chore(deps): update dependency codespell to v2.4.3

chore(deps): update module github.com/go-git/go-git/v5 to v5.19.2
chore(deps): update otel/weaver docker tag to v0.25.1
2026-07-29 13:01:17 +00:00 · 2026-07-29 12:02:00 +00:00 · 2026-07-29 02:00:47 +00:00 · 2026-07-24 20:01:06 +00:00 · 2026-07-16 02:01:04 +00:00 · 2026-07-15 12:00:52 +00:00
110 changed files with 8455 additions and 25892 deletions
@@ -84,38 +84,3 @@ build-mo:

 release:
 	@goreleaser release --clean
-
-CLIENT_VM := abra-client
-vm-client-status:
-	sudo systemctl status microvm@$(CLIENT_VM).service
-vm-client-create:
-	sudo microvm -f git+file://$$(pwd) -c $(CLIENT_VM)
-vm-client-start:
-	sudo systemctl start microvm@$(CLIENT_VM).service
-vm-client-update:
-	sudo microvm -R -f git+file://$$(pwd) -u $(CLIENT_VM) 
-vm-client-run:
-	sudo microvm -f git+file://$$(pwd) -r $(CLIENT_VM)
-vm-client-stop:
-	sudo systemctl stop microvm@$(CLIENT_VM)
-vm-client-delete: vm-client-stop
-	sudo rm -rf /var/lib/microvms/$(CLIENT_VM)
-
-SERVER_VM := abra-server
-vm-server-status:
-	sudo systemctl status microvm@$(SERVER_VM).service
-vm-server-create:
-	sudo microvm -f git+file://$$(pwd) -c $(SERVER_VM)
-vm-server-start:
-	sudo systemctl start microvm@$(SERVER_VM).service
-vm-server-update:
-	sudo microvm -R -f git+file://$$(pwd) -u $(SERVER_VM) 
-vm-server-run:
-	sudo microvm -f git+file://$$(pwd) -r $(SERVER_VM)
-vm-server-stop:
-	sudo systemctl stop microvm@$(SERVER_VM)
-vm-server-delete: vm-stop
-	sudo rm -rf /var/lib/microvms/$(SERVER_VM)
-
-test-integration:
-	ssh-keygen -t ed25519 -f ./test-integration -q -N "" -C "abra integration test"
@@ -18,48 +18,6 @@
        "type": "github"
      }
    },
-    "home-manager": {
-      "inputs": {
-        "nixpkgs": [
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1785119570,
-        "narHash": "sha256-Rgs2xKnGLFWQscxUaXX07oyZeuMDOHEbqDOsgliLFGM=",
-        "owner": "nix-community",
-        "repo": "home-manager",
-        "rev": "d4fd24667c8cbef124bb70a20380cab75ec8474d",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nix-community",
-        "ref": "release-26.05",
-        "repo": "home-manager",
-        "type": "github"
-      }
-    },
-    "microvm": {
-      "inputs": {
-        "nixpkgs": [
-          "nixpkgs"
-        ],
-        "spectrum": "spectrum"
-      },
-      "locked": {
-        "lastModified": 1784666190,
-        "narHash": "sha256-xgfS6slV7J3baMooNN1UuBi51RIgg9y0DbCxfSA0668=",
-        "owner": "astro",
-        "repo": "microvm.nix",
-        "rev": "fa5340ac684cdce8a22b6d4a0bcebb0cc999275e",
-        "type": "github"
-      },
-      "original": {
-        "owner": "astro",
-        "repo": "microvm.nix",
-        "type": "github"
-      }
-    },
    "nixpkgs": {
      "locked": {
        "lastModified": 1778443072,
@@ -79,27 +37,9 @@
    "root": {
      "inputs": {
        "flake-utils": "flake-utils",
-        "home-manager": "home-manager",
-        "microvm": "microvm",
        "nixpkgs": "nixpkgs"
      }
    },
-    "spectrum": {
-      "flake": false,
-      "locked": {
-        "lastModified": 1783694892,
-        "narHash": "sha256-xO8f7Qng+18FK2UlB9vcrkxCaQMCt5WjCH24aW/11eg=",
-        "ref": "refs/heads/main",
-        "rev": "24c4346e30fdea8d8e80f34aec3554a15a667d24",
-        "revCount": 1410,
-        "type": "git",
-        "url": "https://spectrum-os.org/git/spectrum"
-      },
-      "original": {
-        "type": "git",
-        "url": "https://spectrum-os.org/git/spectrum"
-      }
-    },
    "systems": {
      "locked": {
        "lastModified": 1681028828,
@@ -3,71 +3,35 @@

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
-    home-manager = {
-      url = "github:nix-community/home-manager/release-26.05";
-      inputs.nixpkgs.follows = "nixpkgs";
-    };
    flake-utils.url = "github:numtide/flake-utils";
-    microvm = {
-      url = "github:astro/microvm.nix";
-      inputs.nixpkgs.follows = "nixpkgs";
-    };
  };

  outputs =
    {
      self,
      nixpkgs,
-      microvm,
-      home-manager,
      flake-utils,
    }:
-    let
-      system = "x86_64-linux";
-      pkgs = nixpkgs.legacyPackages.${system};
-      publicKey = builtins.readFile ./test-integration.pub;
-      privateKey = builtins.readFile ./test-integration;
-    in
-    {
-      nixosConfigurations = {
-        abra-client = nixpkgs.lib.nixosSystem {
-          system = "x86_64-linux";
-          modules = [
-            microvm.nixosModules.microvm
-            home-manager.nixosModules.home-manager
-            ./nix/hosts/client/configuration.nix
-          ];
-          specialArgs = { inherit publicKey privateKey; };
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      {
+        packages = rec {
+          abra = pkgs.callPackage ./package.nix { };
+          default = abra;
        };
-        abra-server = nixpkgs.lib.nixosSystem {
-          system = "x86_64-linux";
-          modules = [
-            microvm.nixosModules.microvm
-            ./nix/hosts/server/configuration.nix
-          ];
-          specialArgs = { inherit publicKey privateKey; };
+        apps = rec {
+          abra = flake-utils.lib.mkApp { drv = self.packages.${system}.abra; };
+          default = abra;
        };
-      };
-      packages = rec {
-        abra = pkgs.callPackage ./package.nix { };
-        default = abra;
-      };
-      apps = rec {
-        abra = flake-utils.lib.mkApp { drv = self.packages.${system}.abra; };
-        default = abra;
-      };
-      devShells.${system}.default = pkgs.mkShell {
-        # testing env variables
-        BATS_LIB_PATH = "~/.local/share/bats/";
-        TEST_SERVER = "abra.local";
-        ABRA_DIR = "$HOME/.abra_test";
-
-        packages = with pkgs; [
-          go_1_26
-          gnumake
-          gopls
-        ];
-      };
-
-    };
+        devShells.default = pkgs.mkShell {
+          packages = with pkgs; [
+            go_1_26
+            gnumake
+          ];
+        };
+      }
+    );
 }
@@ -13,14 +13,14 @@ require (
 	github.com/docker/cli v28.4.0+incompatible
 	github.com/docker/docker v28.5.2+incompatible
 	github.com/docker/go-units v0.5.0
-	github.com/go-git/go-git/v5 v5.19.1
+	github.com/go-git/go-git/v5 v5.19.2
 	github.com/google/go-cmp v0.7.0
 	github.com/leonelquinteros/gotext v1.7.2
 	github.com/moby/sys/signal v0.7.1
 	github.com/moby/term v0.5.2
 	github.com/pkg/errors v0.9.1
 	github.com/schollz/progressbar/v3 v3.19.1
-	golang.org/x/term v0.44.0
+	golang.org/x/term v0.45.0
 	gopkg.in/yaml.v3 v3.0.1
 	gotest.tools/v3 v3.5.2
 )
@@ -124,10 +124,10 @@ require (
 	go.opentelemetry.io/proto/otlp v1.10.0 // indirect
 	go.yaml.in/yaml/v2 v2.4.4 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
-	golang.org/x/crypto v0.50.0 // indirect
+	golang.org/x/crypto v0.53.0 // indirect
 	golang.org/x/exp v0.0.0-20260410095643-746e56fc9e2f // indirect
-	golang.org/x/net v0.53.0 // indirect
-	golang.org/x/text v0.36.0 // indirect
+	golang.org/x/net v0.56.0 // indirect
+	golang.org/x/text v0.39.0 // indirect
 	golang.org/x/time v0.15.0 // indirect
 	google.golang.org/genproto/googleapis/api v0.0.0-20260401024825-9d38bb4040a9 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9 // indirect
@@ -155,7 +155,7 @@ require (
 	github.com/stretchr/testify v1.11.1
 	github.com/theupdateframework/notary v0.7.0 // indirect
 	github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb // indirect
-	golang.org/x/sys v0.46.0
+	golang.org/x/sys v0.47.0
 )

 replace github.com/docker/cli v28.4.0+incompatible => git.coopcloud.tech/toolshed/docker-cli v28.5.3-0.20260202112816-30df2d0b3a00+incompatible
@@ -393,8 +393,8 @@ github.com/go-git/go-billy/v5 v5.9.0 h1:jItGXszUDRtR/AlferWPTMN4j38BQ88XnXKbilmm
 github.com/go-git/go-billy/v5 v5.9.0/go.mod h1:jCnQMLj9eUgGU7+ludSTYoZL/GGmii14RxKFj7ROgHw=
 github.com/go-git/go-git-fixtures/v4 v4.3.2-0.20231010084843-55a94097c399 h1:eMje31YglSBqCdIqdhKBW8lokaMrL3uTkpGYlE2OOT4=
 github.com/go-git/go-git-fixtures/v4 v4.3.2-0.20231010084843-55a94097c399/go.mod h1:1OCfN199q1Jm3HZlxleg+Dw/mwps2Wbk9frAWm+4FII=
-github.com/go-git/go-git/v5 v5.19.1 h1:nX27AnaU43/K5bKktKwgBmR9lawoYVe1Ckg0rgzzN00=
-github.com/go-git/go-git/v5 v5.19.1/go.mod h1:Pb1v0c7/g8aGQJwx9Us09W85yGoyvSwuhEGMH7zjDKQ=
+github.com/go-git/go-git/v5 v5.19.2 h1:wkfn7vOlUBu8ivAWKBWisTiwJK4jYHzTF8Ndv1LyGqY=
+github.com/go-git/go-git/v5 v5.19.2/go.mod h1:QqCBE1EFN5ddFmrliLQ3/ntRCUjZU3EJuwuB/jWEHjk=
 github.com/go-gl/glfw v0.0.0-20190409004039-e6da0acd62b1/go.mod h1:vR7hzQXu2zJy9AVAgeJqvqgH9Q5CA+iKCZ2gyEVpxRU=
 github.com/go-gl/glfw/v3.3/glfw v0.0.0-20191125211704-12ad95a8df72/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=
 github.com/go-gl/glfw/v3.3/glfw v0.0.0-20200222043503-6f7a984d4dc4/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=
@@ -966,8 +966,8 @@ golang.org/x/crypto v0.0.0-20201117144127-c1f2f97bffc9/go.mod h1:jdWPYTVW3xRLrWP
 golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/crypto v0.0.0-20220622213112-05595931fe9d/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
-golang.org/x/crypto v0.50.0 h1:zO47/JPrL6vsNkINmLoo/PH1gcxpls50DNogFvB5ZGI=
-golang.org/x/crypto v0.50.0/go.mod h1:3muZ7vA7PBCE6xgPX7nkzzjiUq87kRItoJQM1Yo8S+Q=
+golang.org/x/crypto v0.53.0 h1:QZ4Muo8THX6CizN2vPPd5fBGHyogrdK9fG4wLPFUsto=
+golang.org/x/crypto v0.53.0/go.mod h1:DNLU434OwVakk9PzuwV8w62mAJpRJL3vsgcfp4Qnsio=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190510132918-efd6b22b2522/go.mod h1:ZjyILWgesfNpC6sMxTJOJm9Kp84zZh5NQWvqDGG3Qr8=
@@ -1043,8 +1043,8 @@ golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96b
 golang.org/x/net v0.0.0-20210825183410-e898025ed96a/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
-golang.org/x/net v0.53.0 h1:d+qAbo5L0orcWAr0a9JweQpjXF19LMXJE8Ey7hwOdUA=
-golang.org/x/net v0.53.0/go.mod h1:JvMuJH7rrdiCfbeHoo3fCQU24Lf5JJwT9W3sJFulfgs=
+golang.org/x/net v0.56.0 h1:Rw8j/hFzGvJUZwNBXnAtf5sVDVt+65SK2C7IxCxZt5o=
+golang.org/x/net v0.56.0/go.mod h1:D3Ku6r+V6JROoZK144D2XfMHFcMq/0zSfLelVTCFKec=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
@@ -1139,13 +1139,13 @@ golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.46.0 h1:noSf2Fq6F8DBgS+LysIkx7rIExoNHJsxOAtPp4rthXw=
-golang.org/x/sys v0.46.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/sys v0.47.0 h1:o7XGOvZQCADBQQ4Y7VNq2dRWQR7JmOUW8Kxx4ZsNgWs=
+golang.org/x/sys v0.47.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
-golang.org/x/term v0.44.0 h1:0rLvDRCtNj0gZkyIXhCyOb2OAzEhLVqc4B+hrsBhrmc=
-golang.org/x/term v0.44.0/go.mod h1:7ze4MdzUzLXpSAoFP1H0bOI9aXDqveSvatT5vKcFh2Y=
+golang.org/x/term v0.45.0 h1:NwWyBmoJCbfTHpxrWoZ9C6/VxOf7ic219I8xZZFdrf0=
+golang.org/x/term v0.45.0/go.mod h1:9aqxs0blBcrm/n0L9QW0aRVD+ktan8ssZromtqJC43w=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
@@ -1155,8 +1155,8 @@ golang.org/x/text v0.3.4/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/text v0.4.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
-golang.org/x/text v0.36.0 h1:JfKh3XmcRPqZPKevfXVpI1wXPTqbkE5f7JA92a55Yxg=
-golang.org/x/text v0.36.0/go.mod h1:NIdBknypM8iqVmPiuco0Dh6P5Jcdk8lJL0CUebqK164=
+golang.org/x/text v0.39.0 h1:UbZz4pLOvn600D6Oh6GGEI6VAmndrEBLv8/6BEXzyus=
+golang.org/x/text v0.39.0/go.mod h1:3UwRclnC2g0TU9x8PZiyfOajCd1zaUNHF9cvqcQZ+ZM=
 golang.org/x/time v0.0.0-20180412165947-fbb02b2291d2/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
@@ -1,162 +0,0 @@
-{
-  lib,
-  pkgs,
-  publicKey,
-  privateKey,
-  ...
-}:
-let
-  index = 2;
-  mac = "00:00:00:00:00:01";
-  serverIp = "10.0.0.3";
-in
-{
-  microvm = {
-    vcpu = 4;
-    mem = 2049; # see issue related in microvm repo with 2048, so add 1MB
-    interfaces = [
-      {
-        id = "vm${toString index}";
-        type = "tap";
-        inherit mac;
-      }
-    ];
-    shares = [
-      {
-        proto = "virtiofs";
-        tag = "repo";
-        # Source path can be absolute or relative
-        # to /var/lib/microvms/$hostName
-        source = "/home/dev/Documents/abra";
-        mountPoint = "/home/dev/abra";
-      }
-    ];
-  };
-
-  boot.tmp = {
-    useTmpfs = true;
-    tmpfsSize = "2G";
-  };
-
-  networking = {
-    hostName = "abra-client";
-    useNetworkd = true;
-  };
-  systemd.network.networks."10-eth" = {
-    matchConfig.MACAddress = mac;
-    # Static IP configuration
-    address = [
-      "10.0.0.${toString index}/32"
-      "fec0::${lib.toHexString index}/128"
-    ];
-    routes = [
-      {
-        # A route to the host
-        Destination = "10.0.0.0/32";
-        GatewayOnLink = true;
-      }
-      {
-        # Route to server
-        Destination = "${serverIp}/32";
-        Gateway = "10.0.0.0";
-        GatewayOnLink = true;
-      }
-      {
-        # Default route
-        Destination = "0.0.0.0/0";
-        Gateway = "10.0.0.0";
-        GatewayOnLink = true;
-      }
-      {
-        # Default route
-        Destination = "::/0";
-        Gateway = "fec0::";
-        GatewayOnLink = true;
-      }
-    ];
-    networkConfig = {
-      # DNS servers no longer come from DHCP nor Router
-      # Advertisements. Perhaps you want to change the defaults:
-      DNS = [
-        # Quad9.net
-        "9.9.9.9"
-        "149.112.112.112"
-        "2620:fe::fe"
-        "2620:fe::9"
-      ];
-    };
-  };
-
-  # open the ports to allow ssh access from the host
-  networking.firewall.allowedTCPPorts = [ 22 ];
-  networking.firewall.allowedUDPPorts = [ 22 ];
-
-  networking.extraHosts = ''
-    ${serverIp} abra.local
-    ${serverIp} app_check_bats.abra.local
-  '';
-
-  environment.variables = {
-    CGO_ENABLED = 0;
-    TEST_SERVER = "abra.local";
-    ABRA_DIR = "$HOME/.abra_test";
-  };
-
-  users.users.dev = {
-    isNormalUser = true;
-    password = "test";
-    home = "/home/dev";
-    description = "Alice Foobar";
-    extraGroups = [
-      "wheel"
-      "networkmanager"
-    ];
-    openssh.authorizedKeys.keys = [
-      publicKey
-    ];
-  };
-  # ssh agent with askpass
-  programs.ssh = {
-    startAgent = true;
-  };
-  services.openssh = {
-    enable = true;
-    settings = {
-      PasswordAuthentication = false;
-      PermitRootLogin = "no";
-      AllowUsers = [ "dev" ];
-    };
-  };
-  programs.git.enable = true;
-
-  environment.systemPackages = with pkgs; [
-    # build dependencies, copied from flake.nix
-    go_1_26
-    gnumake
-    # testing dependencies
-    (bats.withLibraries (p: [
-      p.bats-assert
-      p.bats-file
-      p.bats-support
-    ]))
-    jq
-  ];
-
-  home-manager = {
-    useGlobalPkgs = true;
-    useUserPackages = true;
-    users.dev =
-      { ... }:
-      {
-        imports = [
-          ./home.nix
-        ];
-      };
-    # pass args to home-manager
-    extraSpecialArgs = {
-      publicKey = publicKey;
-      privateKey = privateKey;
-      serverIp = serverIp;
-    };
-  };
-}
@@ -1,41 +0,0 @@
-{
-  serverIp,
-  ...
-}:
-{
-  # Home Manager needs a bit of information about you and the
-  # paths it should manage.
-  home.username = "dev";
-  home.homeDirectory = "/home/dev";
-
-  # This value determines the Home Manager release that your
-  # configuration is compatible with. This helps avoid breakage
-  # when a new Home Manager release introduces backwards
-  # incompatible changes.
-  #
-  # You can update Home Manager without changing this value. See
-  # the Home Manager release notes for a list of state version
-  # changes in each release.
-  home.stateVersion = "26.05";
-
-  # Let Home Manager install and manage itself.
-  programs.home-manager.enable = true;
-  programs.ssh = {
-    enable = true;
-    enableDefaultConfig = false;
-    settings = {
-      "abra.local" = {
-        HostName = serverIp;
-        User = "dev";
-        Port = 22;
-        IdentityFile = "/home/dev/abra/test-integration";
-      };
-      "*.abra.local" = {
-        HostName = serverIp;
-        User = "dev";
-        Port = 22;
-        IdentityFile = "/home/dev/abra/test-integration";
-      };
-    };
-  };
-}
@@ -1,116 +0,0 @@
-{
-  lib,
-  publicKey,
-  ...
-}:
-let
-  index = 3;
-  mac = "00:00:00:00:00:02";
-  clientIp = "10.0.0.2";
-in
-{
-  microvm = {
-    vcpu = 2;
-    mem = 2049; # see issue related in microvm repo with 2048, so add 1MB
-    interfaces = [
-      {
-        id = "vm${toString index}";
-        type = "tap";
-        inherit mac;
-      }
-    ];
-  };
-
-  boot.tmp = {
-    useTmpfs = true;
-    tmpfsSize = "2G";
-  };
-
-  networking = {
-    hostName = "abra-server";
-    useNetworkd = true;
-  };
-  systemd.network.networks."11-eth" = {
-    matchConfig.MACAddress = mac;
-    # Static IP configuration
-    address = [
-      "10.0.0.${toString index}/32"
-      "fec0::${lib.toHexString index}/128"
-    ];
-    routes = [
-      {
-        # A route to the host
-        Destination = "10.0.0.0/32";
-        GatewayOnLink = true;
-      }
-      {
-        # Route to server
-        Destination = "${clientIp}/32";
-        Gateway = "10.0.0.0";
-        GatewayOnLink = true;
-      }
-      {
-        # Default route
-        Destination = "0.0.0.0/0";
-        Gateway = "10.0.0.0";
-        GatewayOnLink = true;
-      }
-      {
-        # Default route
-        Destination = "::/0";
-        Gateway = "fec0::";
-        GatewayOnLink = true;
-      }
-    ];
-    networkConfig = {
-      # DNS servers no longer come from DHCP nor Router
-      # Advertisements. Perhaps you want to change the defaults:
-      DNS = [
-        # Quad9.net
-        "9.9.9.9"
-        "149.112.112.112"
-        "2620:fe::fe"
-        "2620:fe::9"
-      ];
-    };
-  };
-
-  # open the ports to allow ssh access from the host
-  networking.firewall.allowedTCPPorts = [
-    22
-    80
-    443
-  ];
-  networking.firewall.allowedUDPPorts = [
-    22
-    80
-    443
-  ];
-
-  users.users.dev = {
-    isNormalUser = true;
-    password = "test";
-    home = "/home/dev";
-    description = "Alice Foobar";
-    extraGroups = [
-      "wheel"
-      "networkmanager"
-      "docker"
-    ];
-    openssh.authorizedKeys.keys = [
-      publicKey
-    ];
-  };
-  services.openssh = {
-    enable = true;
-    settings = {
-      PasswordAuthentication = false;
-      PermitRootLogin = "no";
-      AllowUsers = [ "dev" ];
-    };
-  };
-  virtualisation.docker = {
-    enable = true;
-    liveRestore = false;
-  };
-}
@@ -3,7 +3,7 @@ version: "3.8"

 services:
  app:
-    image: nginx:1.31.2
+    image: nginx:1.31.3
    secrets:
      - test_pass_one
      - test_pass_two
@@ -3,7 +3,7 @@ version: "3.8"

 services:
  app:
-    image: nginx:1.31.2
+    image: nginx:1.31.3
    networks:
      - proxy
    deploy:
@@ -5,3 +5,4 @@ profile.out
 .tmp/
 .git-dist/
 .vscode
+build/tools/
@@ -110,6 +110,48 @@ func (r ReferenceName) IsTag() bool {
 	return strings.HasPrefix(string(r), refTagPrefix)
 }

+// IsSafe reports whether the reference name can be safely turned into a path
+// under the .git directory, mirroring Git's refname_is_safe (refs.c). A name
+// is safe when it is either:
+//
+//   - under "refs/", non-empty after the prefix, containing no backslash and
+//     no empty, "." or ".." path component (so it cannot escape the refs/
+//     sub-tree, or alias another name, once turned into a path); or
+//   - a one-level pseudo-ref whose spelling is restricted to [A-Z_]
+//     (e.g. HEAD, ORIG_HEAD, FETCH_HEAD).
+//
+// Everything else — a lowercase or mixed one-level name such as "config" or
+// "index", an absolute or drive-prefixed name, or a refs/ name that escapes —
+// is unsafe, because it could resolve onto unrelated repository metadata.
+func (r ReferenceName) IsSafe() bool {
+	s := string(r)
+	if s == "" {
+		return false
+	}
+
+	if rest, ok := strings.CutPrefix(s, refPrefix); ok {
+		// '\' is a path separator on Windows, so a refs/ name containing one
+		// could escape the sub-tree or alias another name once turned into a
+		// path; reject it outright (check_refname_format forbids '\' too).
+		if rest == "" || strings.Contains(rest, "\\") {
+			return false
+		}
+		for part := range strings.SplitSeq(rest, "/") {
+			if part == "" || part == "." || part == ".." {
+				return false
+			}
+		}
+		return true
+	}
+
+	for i := 0; i < len(s); i++ {
+		if (s[i] < 'A' || s[i] > 'Z') && s[i] != '_' {
+			return false
+		}
+	}
+	return true
+}
+
 func (r ReferenceName) String() string {
 	return string(r)
 }
@@ -16,6 +16,7 @@ import (
 	"strings"
 	"time"

+	"github.com/go-git/go-git/v5/internal/pathutil"
 	"github.com/go-git/go-git/v5/plumbing"
 	"github.com/go-git/go-git/v5/plumbing/hash"
 	"github.com/go-git/go-git/v5/storage"
@@ -79,8 +80,52 @@ var (
 	// resolve outside the modules/ subtree, mirroring canonical Git's
 	// "ignoring suspicious submodule name" defence.
 	ErrModuleNameEscape = errors.New("submodule name escapes modules/ directory")
+	// ErrReferenceNameEscape is returned when a reference name would
+	// resolve outside its reference sub-tree once turned into a path
+	// under the .git directory (e.g. a name with a ".." component).
+	ErrReferenceNameEscape = errors.New("reference name escapes the reference storage")
 )

+// isPathSep reports whether r is a path separator in reference names.
+// It treats both '/' and '\\' as separators to harden against cross-OS paths.
+func isPathSep(r rune) bool { return r == '/' || r == '\\' }
+
+// validReferenceName rejects reference names that cannot be safely turned into
+// a path under the .git directory. A loose reference is stored verbatim at
+// ".git/<name>", so a crafted name — for instance one advertised by a malicious
+// remote — could climb out of its reference sub-tree and read, overwrite, or
+// delete unrelated metadata such as .git/config.
+//
+// The storage-safety gate is plumbing.ReferenceName.IsSafe, mirroring Git's
+// refname_is_safe: a name must be under refs/ without escaping it, or be a
+// [A-Z_] pseudo-ref. This alone rejects absolute, drive-prefixed, escaping and
+// single-level metadata names. On top of it, this adds filesystem-specific
+// hardening that IsSafe's literal check does not cover: control characters, and
+// components a case-insensitive/NTFS/HFS+ filesystem would fold back to "." or
+// ".." (trailing dots/spaces, Alternate Data Streams, ignorable Unicode code
+// points), delegated to pathutil.IsHFSDot and pathutil.IsNTFSDot with "." as
+// the needle — as validSubmoduleName does — and run regardless of host OS.
+func validReferenceName(name plumbing.ReferenceName) error {
+	if !name.IsSafe() {
+		return fmt.Errorf("%w: %q is not under refs/ nor a valid pseudo-ref", ErrReferenceNameEscape, string(name))
+	}
+
+	s := string(name)
+	for i := 0; i < len(s); i++ {
+		if s[i] < 0x20 || s[i] == 0x7f {
+			return fmt.Errorf("%w: %q", ErrReferenceNameEscape, s)
+		}
+	}
+	for _, part := range strings.FieldsFunc(s, isPathSep) {
+		// IsNTFSDot/IsHFSDot with a "." needle match ".." and its disguises
+		// but not a bare ".", so reject that component explicitly too.
+		if part == "." || pathutil.IsHFSDot(part, ".") || pathutil.IsNTFSDot(part, ".", "") {
+			return fmt.Errorf("%w: %q", ErrReferenceNameEscape, s)
+		}
+	}
+	return nil
+}
+
 // Options holds configuration for the storage.
 type Options struct {
 	// ExclusiveAccess means that the filesystem is not modified externally
@@ -706,6 +751,10 @@ func (d *DotGit) checkReferenceAndTruncate(f billy.File, old *plumbing.Reference
 }

 func (d *DotGit) SetRef(r, old *plumbing.Reference) error {
+	if err := validReferenceName(r.Name()); err != nil {
+		return err
+	}
+
 	var content string
 	switch r.Type() {
 	case plumbing.SymbolicReference:
@@ -741,6 +790,10 @@ func (d *DotGit) Refs() ([]*plumbing.Reference, error) {

 // Ref returns the reference for a given reference name.
 func (d *DotGit) Ref(name plumbing.ReferenceName) (*plumbing.Reference, error) {
+	if err := validReferenceName(name); err != nil {
+		return nil, err
+	}
+
 	ref, err := d.readReferenceFile(".", name.String())
 	if err == nil {
 		return ref, nil
@@ -804,6 +857,10 @@ func (d *DotGit) packedRef(name plumbing.ReferenceName) (*plumbing.Reference, er

 // RemoveRef removes a reference by name.
 func (d *DotGit) RemoveRef(name plumbing.ReferenceName) error {
+	if err := validReferenceName(name); err != nil {
+		return err
+	}
+
 	path := d.fs.Join(".", name.String())
 	_, err := d.fs.Stat(path)
 	if err == nil {
@@ -583,6 +583,10 @@ func (w *Worktree) checkoutChangeSubmodule(name string,
 			return err
 		}

+		if err := w.clearBlockingSymlinks(name); err != nil {
+			return err
+		}
+
 		if err := w.Filesystem.MkdirAll(name, mode); err != nil {
 			return err
 		}
@@ -626,7 +630,70 @@ func (w *Worktree) checkoutChangeRegularFile(name string,
 	return nil
 }

+// clearBlockingSymlinks removes a symlink that is in the way of
+// materialising name, so the checkout writes a real entry in its place
+// instead of following the link out of the worktree. Two cases:
+//
+//   - a leading directory component that is a symlink (e.g. "s" while
+//     writing "s/config", where "s" links to ".git"): OpenFile/MkdirAll
+//     would traverse it, so the write would land under the link's target.
+//   - the final component itself being a symlink (e.g. writing "s" while
+//     "s" links to ".git/config"): OpenFile with O_TRUNC, or Symlink,
+//     would follow/replace through it and clobber the target.
+//
+// A symlink can never be a legitimate parent of, or the destination for,
+// a tracked entry, so removing it is always correct. This mirrors upstream
+// Git's forced checkout, which unlinks a blocking symlink in the leading
+// path (create_directories) and unlinks an existing entry before
+// write_entry.
+// https://github.com/git/git/blob/v2.54.0/entry.c#L50
+func (w *Worktree) clearBlockingSymlinks(name string) error {
+	var dirs []string
+	for dir := filepath.Dir(name); dir != "." && dir != "" && dir != string(filepath.Separator); dir = filepath.Dir(dir) {
+		dirs = append(dirs, dir)
+	}
+	// Leading components, shallowest-first: removing the shallowest symlink
+	// invalidates every component beneath it, so a single removal is enough.
+	for i := len(dirs) - 1; i >= 0; i-- {
+		fi, err := w.Filesystem.Lstat(dirs[i])
+		if err != nil {
+			// A missing component is created as a real directory by the
+			// checkout. Any other error means we cannot tell whether it is
+			// a symlink, so surface it instead of leaving a blocking link in
+			// place and failing later in a harder-to-diagnose way.
+			if os.IsNotExist(err) {
+				continue
+			}
+			return err
+		}
+		if fi.Mode()&os.ModeSymlink != 0 {
+			return w.Filesystem.Remove(dirs[i])
+		}
+	}
+	// Final component: an existing symlink here would be followed by the
+	// subsequent OpenFile/Symlink/MkdirAll, so replace it.
+	fi, err := w.Filesystem.Lstat(name)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return err
+	}
+	if fi.Mode()&os.ModeSymlink != 0 {
+		return w.Filesystem.Remove(name)
+	}
+	return nil
+}
+
 func (w *Worktree) checkoutFile(f *object.File) (err error) {
+	// checkoutFile is the materialisation boundary for tracked entries.
+	// Remove any blocking symlink first so the subsequent OpenFile or
+	// Symlink call writes the entry itself instead of following a planted
+	// final-component link in the underlying filesystem.
+	if err := w.clearBlockingSymlinks(f.Name); err != nil {
+		return err
+	}
+
 	mode, err := f.Mode.ToOSFileMode()
 	if err != nil {
 		return
@@ -35,10 +35,25 @@ func defaultProtectNTFS() bool {
 	return true
 }

-// worktreeFilesystem wraps a billy.Filesystem and validates every path passed
-// to a mutating operation. This prevents writing to, or deleting from,
-// dangerous locations (e.g. .git/*, ../) regardless of which worktree
-// code path triggers the operation.
+// worktreeFilesystem wraps a billy.Filesystem and validates every path it
+// is handed, so worktree operations cannot use dangerous paths at the
+// boundary. Two layers apply:
+//
+//   - validPath rejects dangerous path *strings*: .git and its HFS+/NTFS
+//     variants, "..", control characters, volume names.
+//   - validNoLeadingSymlink rejects paths whose leading directories
+//     already exist on disk as symlinks, so a write or delete cannot
+//     follow a planted link out of the tree.
+//
+// Both layers run on every mutating operation (validWritePath) and every
+// read (validReadPath). Chroot additionally refuses a symlink as the final
+// component, so a sub-filesystem such as a submodule worktree cannot be
+// scoped to a redirected target.
+//
+// The wrapper intentionally stops at leading-component traversal. Callers
+// that need final-component no-follow semantics for materialisation
+// (checkoutFile) enforce that directly by removing the blocking symlink
+// before opening the destination path.
 type worktreeFilesystem struct {
 	billy.Filesystem
 	protectNTFS bool
@@ -50,7 +65,7 @@ func newWorktreeFilesystem(fs billy.Filesystem, protectNTFS, protectHFS bool) *w
 }

 func (sfs *worktreeFilesystem) Create(filename string) (billy.File, error) {
-	if err := sfs.validPath(filename); err != nil {
+	if err := sfs.validWritePath(filename); err != nil {
 		return nil, fmt.Errorf("create: %w", err)
 	}
 	return sfs.Filesystem.Create(filename)
@@ -64,7 +79,7 @@ func (sfs *worktreeFilesystem) Open(filename string) (billy.File, error) {
 }

 func (sfs *worktreeFilesystem) OpenFile(filename string, flag int, perm os.FileMode) (billy.File, error) {
-	if err := sfs.validPath(filename); err != nil {
+	if err := sfs.validWritePath(filename); err != nil {
 		return nil, fmt.Errorf("openfile: %w", err)
 	}
 	return sfs.Filesystem.OpenFile(filename, flag, perm)
@@ -78,14 +93,14 @@ func (sfs *worktreeFilesystem) Stat(filename string) (os.FileInfo, error) {
 }

 func (sfs *worktreeFilesystem) Remove(filename string) error {
-	if err := sfs.validPath(filename); err != nil {
+	if err := sfs.validWritePath(filename); err != nil {
 		return fmt.Errorf("remove: %w", err)
 	}
 	return sfs.Filesystem.Remove(filename)
 }

 func (sfs *worktreeFilesystem) Rename(from, to string) error {
-	if err := sfs.validPath(from, to); err != nil {
+	if err := sfs.validWritePath(from, to); err != nil {
 		return fmt.Errorf("rename: %w", err)
 	}
 	return sfs.Filesystem.Rename(from, to)
@@ -106,7 +121,7 @@ func (sfs *worktreeFilesystem) Lstat(filename string) (os.FileInfo, error) {
 }

 func (sfs *worktreeFilesystem) Symlink(target, link string) error {
-	if err := sfs.validPath(link); err != nil {
+	if err := sfs.validWritePath(link); err != nil {
 		return fmt.Errorf("symlink: %w", err)
 	}
 	if err := sfs.validSymlinkName(link); err != nil {
@@ -131,7 +146,7 @@ func (sfs *worktreeFilesystem) MkdirAll(path string, perm os.FileMode) error {
 	if path == "" || path == "." || path == "/" {
 		return nil
 	}
-	if err := sfs.validPath(path); err != nil {
+	if err := sfs.validWritePath(path); err != nil {
 		return fmt.Errorf("mkdirall: %w", err)
 	}
 	return sfs.Filesystem.MkdirAll(path, perm)
@@ -145,18 +160,39 @@ func (sfs *worktreeFilesystem) Chroot(path string) (billy.Filesystem, error) {
 	if err := sfs.validReadPath(path); err != nil {
 		return nil, fmt.Errorf("chroot: %w", err)
 	}
+	// Chroot scopes a sub-filesystem to path, so the final component must
+	// be a real directory too: a symlink there would silently redirect the
+	// scope (e.g. a submodule worktree) to a target outside the tree. This
+	// is the "valid path, wrong target" case that validNoLeadingSymlink,
+	// which only inspects leading components, does not cover.
+	//
+	// A non-existent target is fine: Chroot creates it as a real
+	// directory. Any other Lstat error means we cannot prove the target
+	// is not a symlink, so fail closed rather than scope through it.
+	if fi, err := sfs.Filesystem.Lstat(path); err != nil {
+		if !os.IsNotExist(err) {
+			return nil, fmt.Errorf("chroot: cannot stat %q: %w", path, err)
+		}
+	} else if fi.Mode()&os.ModeSymlink != 0 {
+		return nil, fmt.Errorf("chroot: invalid path %q: is a symlink", path)
+	}
 	return sfs.Filesystem.Chroot(path)
 }

-// validReadPath is like validPath but treats the empty string and "." as
-// valid references to the worktree root. Read-side operations on the root
-// (e.g. ReadDir(""), Lstat(".")) are legitimate; mutating the root itself
-// is not, so write-side operations continue to use validPath directly.
+// validReadPath is like validWritePath but treats the empty string and "."
+// as valid references to the worktree root. Read-side operations on the
+// root (e.g. ReadDir(""), Lstat(".")) are legitimate. Mutating the root
+// itself is not, so write-side operations reject it via validPath. Reads
+// are still refused through a leading symlink, so the wrapper never
+// follows a planted link even on the read surface.
 func (sfs *worktreeFilesystem) validReadPath(p string) error {
 	if p == "" || p == "." || p == "/" {
 		return nil
 	}
-	return sfs.validPath(p)
+	if err := sfs.validPath(p); err != nil {
+		return err
+	}
+	return sfs.validNoLeadingSymlink(p)
 }

 var errUnsupportedOperation = errors.New("unsupported operation")
@@ -232,6 +268,55 @@ func (sfs *worktreeFilesystem) validPath(paths ...string) error {
 	return nil
 }

+// validWritePath validates paths for mutating operations. It layers the
+// filesystem-state check validNoLeadingSymlink on top of the string-only
+// checks in validPath, so a write can neither name a dangerous path nor
+// reach one by traversing an existing symlink. Every mutating method on
+// the wrapper funnels through here, so the leading-symlink invariant holds
+// for all worktree writers without each call site having to remember it.
+func (sfs *worktreeFilesystem) validWritePath(paths ...string) error {
+	if err := sfs.validPath(paths...); err != nil {
+		return err
+	}
+	return sfs.validNoLeadingSymlink(paths...)
+}
+
+// validNoLeadingSymlink rejects paths whose leading directory components
+// resolve through a symlink that already exists on the underlying
+// filesystem. validPath guards the path string. This guards the on-disk
+// state, so a write or delete cannot reach outside the worktree by
+// traversing a symlink that a tree or an earlier step left in place.
+//
+// This is the fail-closed backstop for the whole class. Callers that want
+// upstream's replace-and-continue behaviour (checkout) remove the blocking
+// symlink first via clearBlockingSymlinks, so no symlink remains when the
+// write reaches the wrapper. Callers that do not get a safe error,
+// matching upstream Git refusing rather than following the link. See
+// has_symlink_leading_path (symlinks.c) and the check_leading_path guard
+// in unlink_entry (entry.c).
+func (sfs *worktreeFilesystem) validNoLeadingSymlink(paths ...string) error {
+	for _, p := range paths {
+		for dir := filepath.Dir(p); dir != "." && dir != "" && dir != string(filepath.Separator); dir = filepath.Dir(dir) {
+			fi, err := sfs.Filesystem.Lstat(dir)
+			if err != nil {
+				// A missing ancestor is materialised as a real directory,
+				// so it cannot be a symlink and is safe to skip. Any other
+				// error (permission, I/O) means we cannot prove the
+				// component is not a symlink, so fail closed rather than
+				// let the operation traverse an unverified component.
+				if os.IsNotExist(err) {
+					continue
+				}
+				return fmt.Errorf("invalid path %q: cannot stat leading component %q: %w", p, dir, err)
+			}
+			if fi.Mode()&os.ModeSymlink != 0 {
+				return fmt.Errorf("invalid path %q: leading component %q is a symlink", p, dir)
+			}
+		}
+	}
+	return nil
+}
+
 // validSymlinkName checks the per-component name of a symlink for
 // dotfile names that attackers can use to trick a checkout into
 // writing a dangerous symlink. Each path component is compared
@@ -371,7 +371,7 @@ func (w *Worktree) doAdd(path string, ignorePattern []gitignore.Pattern, skipSta
 		}
 	}

-	path = filepath.Clean(path)
+	path = filepath.ToSlash(filepath.Clean(path))

 	if err != nil || !fi.IsDir() {
 		added, h, err = w.doAddFile(idx, s, path, ignorePattern)
@@ -1,4 +1,4 @@
-FROM golang:1.26@sha256:f96cc555eb8db430159a3aa6797cd5bae561945b7b0fe7d0e284c63a3b291609
+FROM golang:1.25@sha256:31c1e53dfc1cc2d269deec9c83f58729fa3c53dc9a576f6426109d1e319e9e9a

 ENV GOOS=linux
 ENV GOARCH=arm
@@ -1,4 +1,4 @@
-FROM golang:1.26@sha256:f96cc555eb8db430159a3aa6797cd5bae561945b7b0fe7d0e284c63a3b291609
+FROM golang:1.25@sha256:31c1e53dfc1cc2d269deec9c83f58729fa3c53dc9a576f6426109d1e319e9e9a

 ENV GOOS=linux
 ENV GOARCH=arm64
@@ -1 +1 @@
-codespell==2.4.2
+codespell==2.4.3
@@ -1,11 +0,0 @@
-// Copyright 2025 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build go1.25
-
-package blake2b
-
-import "hash"
-
-var _ hash.XOF = (*xof)(nil)
@@ -11,6 +11,7 @@
 package hkdf

 import (
+	"crypto/hkdf"
 	"crypto/hmac"
 	"errors"
 	"hash"
@@ -24,15 +25,19 @@ import (
 // Expand invocations and different context values. Most common scenarios,
 // including the generation of multiple keys, should use New instead.
 func Extract(hash func() hash.Hash, secret, salt []byte) []byte {
-	if salt == nil {
-		salt = make([]byte, hash().Size())
+	// Use the stdlib Extract, which disables FIPS 140 enforcement of the HMAC
+	// key (which in HKDF is the salt). The only possible error is FIPS 140
+	// enforcement of the hash, which had to panic under this API anyway. We
+	// don't use the stdlib Expand, because it switched to returning a []byte
+	// instead of an io.Reader, and Expand uses the HMAC key as a key.
+	out, err := hkdf.Extract(hash, secret, salt)
+	if err != nil {
+		panic(err)
 	}
-	extractor := hmac.New(hash, salt)
-	extractor.Write(secret)
-	return extractor.Sum(nil)
+	return out
 }

-type hkdf struct {
+type hkdfReader struct {
 	expander hash.Hash
 	size     int

@@ -43,7 +48,7 @@ type hkdf struct {
 	buf  []byte
 }

-func (f *hkdf) Read(p []byte) (int, error) {
+func (f *hkdfReader) Read(p []byte) (int, error) {
 	// Check whether enough data can be generated
 	need := len(p)
 	remains := len(f.buf) + int(255-f.counter+1)*f.size
@@ -84,7 +89,7 @@ func (f *hkdf) Read(p []byte) (int, error) {
 // 3.3. Most common scenarios will want to use New instead.
 func Expand(hash func() hash.Hash, pseudorandomKey, info []byte) io.Reader {
 	expander := hmac.New(hash, pseudorandomKey)
-	return &hkdf{expander, expander.Size(), info, 1, nil, nil}
+	return &hkdfReader{expander, expander.Size(), info, 1, nil, nil}
 }

 // New returns a Reader, from which keys can be read, using the given hash,
@@ -26,6 +26,7 @@ import (
 	"io"
 	"math/big"
 	"sync"
+	"sync/atomic"

 	"golang.org/x/crypto/ssh"
 )
@@ -307,17 +308,50 @@ func parseKey(in []byte) (out *Key, rest []byte, err error) {
 	}, record.Rest, nil
 }

+// pipelineMaxInFlight is the maximum number of outstanding requests the
+// client will pipeline to the agent before applying backpressure.
+const pipelineMaxInFlight = 32
+
 // client is a client for an ssh-agent process.
+//
+// Exactly one of pipeline / (mu, conn) is set, chosen by NewClient
+// based on whether the underlying transport implements io.Closer.
 type client struct {
-	// conn is typically a *net.UnixConn
+	// pipeline, if non-nil, dispatches requests over a pipelined
+	// connection: requests are written as soon as the wire is
+	// available and responses are routed back to per-call reply
+	// channels in FIFO order by a background reader goroutine.
+	pipeline *pipeline
+
+	// mu and conn are used in fully-serialized mode, when the
+	// transport does not implement io.Closer. Each call takes mu,
+	// writes its request, reads the matching response, and releases
+	// mu before returning. There is no background goroutine.
+	mu   sync.Mutex
 	conn io.ReadWriter
-	// mu is used to prevent concurrent access to the agent
-	mu sync.Mutex
 }

 // NewClient returns an Agent that talks to an ssh-agent process over
 // the given connection.
+//
+// If rw also implements io.Closer (like *net.UnixConn and ssh.Channel
+// do), the returned client pipelines concurrent requests over the
+// connection: callers can issue Sign and other operations from
+// multiple goroutines and they will be written to the agent as soon
+// as the wire is available, rather than waiting for the previous
+// responses. The ssh-agent protocol still requires responses to be
+// returned in request order, so a slow request delays subsequent
+// responses on the same connection (head-of-line blocking).
+//
+// Pipelining requires io.Closer because, on a Write error, the
+// background reader goroutine must be unblocked by closing the
+// underlying connection. When rw does not implement io.Closer
+// this is not possible, so NewClient falls back to fully
+// serializing each request: a single in-flight call at a time.
 func NewClient(rw io.ReadWriter) ExtendedAgent {
+	if rwc, ok := rw.(io.ReadWriteCloser); ok {
+		return &client{pipeline: newPipeline(rwc)}
+	}
 	return &client{conn: rw}
 }

@@ -340,6 +374,16 @@ func (c *client) call(req []byte) (reply interface{}, err error) {
 // bytes of the response are returned; no unmarshalling is
 // performed on the response.
 func (c *client) callRaw(req []byte) (reply []byte, err error) {
+	if c.pipeline != nil {
+		return c.pipeline.call(req)
+	}
+	return c.serialCall(req)
+}
+
+// serialCall implements the fully-serialized request/response path
+// used when the transport is not an io.Closer. It writes req under mu
+// and reads the matching response before returning.
+func (c *client) serialCall(req []byte) (reply []byte, err error) {
 	c.mu.Lock()
 	defer c.mu.Unlock()

@@ -577,6 +621,9 @@ func (c *client) insertKey(s interface{}, comment string, constraints []byte) er
 			Constraints: constraints,
 		})
 	case ed25519.PrivateKey:
+		if len(k) != ed25519.PrivateKeySize {
+			return fmt.Errorf("agent: bad ED25519 key size: %d", len(k))
+		}
 		req = ssh.Marshal(ed25519KeyMsg{
 			Type:        ssh.KeyAlgoED25519,
 			Pub:         []byte(k)[32:],
@@ -588,6 +635,9 @@ func (c *client) insertKey(s interface{}, comment string, constraints []byte) er
 	// general idiom is to pass ed25519.PrivateKey by value, not by pointer.
 	// We still support the pointer variant for backwards compatibility.
 	case *ed25519.PrivateKey:
+		if len(*k) != ed25519.PrivateKeySize {
+			return fmt.Errorf("agent: bad ED25519 key size: %d", len(*k))
+		}
 		req = ssh.Marshal(ed25519KeyMsg{
 			Type:        ssh.KeyAlgoED25519,
 			Pub:         []byte(*k)[32:],
@@ -663,6 +713,13 @@ func (c *client) Add(key AddedKey) error {
 		constraints = append(constraints, agentConstrainConfirm)
 	}

+	for _, ext := range key.ConstraintExtensions {
+		constraints = append(constraints, ssh.Marshal(constrainExtensionAgentMsg{
+			ExtensionName:    ext.ExtensionName,
+			ExtensionDetails: ext.ExtensionDetails,
+		})...)
+	}
+
 	cert := key.Certificate
 	if cert == nil {
 		return c.insertKey(key.PrivateKey, key.Comment, constraints)
@@ -705,6 +762,9 @@ func (c *client) insertCert(s interface{}, cert *ssh.Certificate, comment string
 			Constraints: constraints,
 		})
 	case ed25519.PrivateKey:
+		if len(k) != ed25519.PrivateKeySize {
+			return fmt.Errorf("agent: bad ED25519 key size: %d", len(k))
+		}
 		req = ssh.Marshal(ed25519CertMsg{
 			Type:        cert.Type(),
 			CertBytes:   cert.Marshal(),
@@ -717,6 +777,9 @@ func (c *client) insertCert(s interface{}, cert *ssh.Certificate, comment string
 	// general idiom is to pass ed25519.PrivateKey by value, not by pointer.
 	// We still support the pointer variant for backwards compatibility.
 	case *ed25519.PrivateKey:
+		if len(*k) != ed25519.PrivateKeySize {
+			return fmt.Errorf("agent: bad ED25519 key size: %d", len(*k))
+		}
 		req = ssh.Marshal(ed25519CertMsg{
 			Type:        cert.Type(),
 			CertBytes:   cert.Marshal(),
@@ -854,3 +917,170 @@ func (c *client) Extension(extensionType string, contents []byte) ([]byte, error

 	return buf, nil
 }
+
+// pipelineResult carries either a raw agent reply or an error back to a
+// caller waiting on the response channel.
+type pipelineResult struct {
+	reply []byte
+	err   error
+}
+
+// pipeline implements request pipelining over a single agent connection.
+//
+// Writers serialize on writeMu to both register a reply channel in the
+// pending FIFO queue and write the request bytes on the wire; the two
+// must be atomic so the queue order matches the wire order. A single
+// reader goroutine decodes responses from the connection and dispatches
+// each one to the channel at the head of the queue.
+//
+// pending is a chan-of-chan acting as a FIFO queue with a fixed
+// capacity of pipelineMaxInFlight. The outer channel provides ordering
+// (reads happen in send order) and natural backpressure (a full queue
+// blocks new writers). Each inner channel is buffered with capacity
+// one and is sent to exactly once: either by the reader goroutine
+// with the agent reply, or by shutdown with the terminal error during
+// drain. The cap-one buffer makes the producer's send non-blocking,
+// so the reader and shutdown never have to wait for the caller to be
+// scheduled on the receive.
+//
+// When the reader goroutine exits (on read error or protocol
+// violation), it closes exitCh to wake any writer blocked on the
+// pending queue, then serializes with any in-flight writer to close
+// the pending channel, and finally drains the remaining entries
+// delivering the terminal error to each waiting caller. The
+// pipeline relies on conn implementing io.Closer so a writer that
+// hits a Write error can close the connection to unblock the reader
+// goroutine; NewClient is responsible for only constructing a
+// pipeline when this guarantee holds.
+type pipeline struct {
+	conn io.ReadWriteCloser
+
+	writeMu sync.Mutex
+	// pending is the FIFO queue of reply channels with capacity
+	// pipelineMaxInFlight. See type-level documentation.
+	pending chan chan pipelineResult
+	exitCh  chan struct{}
+
+	// err carries the terminal error to callers blocked on a closed
+	// pipeline. It is stored exactly once by the reader goroutine
+	// before exitCh is closed; every read happens after observing
+	// exitCh closed, so the load synchronises through the close and
+	// is guaranteed to return the stored value (never nil).
+	err atomic.Pointer[error]
+}
+
+func newPipeline(conn io.ReadWriteCloser) *pipeline {
+	p := &pipeline{
+		conn:    conn,
+		pending: make(chan chan pipelineResult, pipelineMaxInFlight),
+		exitCh:  make(chan struct{}),
+	}
+	go p.readLoop()
+	return p
+}
+
+// readLoop decodes responses from conn and dispatches them in FIFO order
+// to reply channels in pending. On any failure it invokes shutdown.
+func (p *pipeline) readLoop() {
+	var finalErr error
+	for {
+		var sizeBuf [4]byte
+		if _, err := io.ReadFull(p.conn, sizeBuf[:]); err != nil {
+			finalErr = err
+			break
+		}
+		respSize := binary.BigEndian.Uint32(sizeBuf[:])
+		if respSize > maxAgentResponseBytes {
+			finalErr = errors.New("response too large")
+			break
+		}
+		buf := make([]byte, respSize)
+		if _, err := io.ReadFull(p.conn, buf); err != nil {
+			finalErr = err
+			break
+		}
+		// Successful writes always enqueue before sending bytes, so
+		// pending has a waiting channel for this response.
+		ch := <-p.pending
+		// The reply channel is buffered with capacity 1 and is only
+		// ever written to once, so this send cannot block.
+		ch <- pipelineResult{reply: buf}
+	}
+	p.shutdown(clientErr(finalErr))
+}
+
+// shutdown is called exactly once, from readLoop, when the reader is
+// terminating. It unblocks pending writers and fails all in-flight
+// requests with finalErr.
+func (p *pipeline) shutdown(finalErr error) {
+	// Publish the terminal error before closing exitCh so any
+	// writer that subsequently observes exitCh closed sees err.
+	p.err.Store(&finalErr)
+
+	// Wake any writer blocked waiting for a slot in the pending queue.
+	close(p.exitCh)
+
+	// Wait for any writer currently inside its critical section to
+	// complete. After this lock, no new writer can reach the send on
+	// pending: they will observe exitCh closed in the select and bail
+	// out before attempting the send.
+	p.writeMu.Lock()
+	close(p.pending)
+	p.writeMu.Unlock()
+
+	// Drain entries that were enqueued but never answered, delivering
+	// the terminal error to their waiting callers. The reply channels
+	// are buffered (cap 1) and written to exactly once, so these sends
+	// cannot block.
+	for ch := range p.pending {
+		ch <- pipelineResult{err: finalErr}
+	}
+}
+
+// call sends req to the agent and returns the matching raw response.
+func (p *pipeline) call(req []byte) ([]byte, error) {
+	replyCh := make(chan pipelineResult, 1)
+
+	p.writeMu.Lock()
+
+	// Priority check: if the reader has already finished shutdown,
+	// pending is closed and sending to it would panic. Bail out now.
+	// Once we pass this check while holding writeMu, shutdown cannot
+	// complete close(pending) until we release writeMu, so the send
+	// below is safe against concurrent closure.
+	select {
+	case <-p.exitCh:
+		p.writeMu.Unlock()
+		return nil, *p.err.Load()
+	default:
+	}
+
+	// Enqueue the reply channel before writing the request, so FIFO
+	// order on the wire matches FIFO order in the pending queue. The
+	// exitCh arm handles the case where the reader errors while we
+	// block on a full queue.
+	select {
+	case p.pending <- replyCh:
+	case <-p.exitCh:
+		p.writeMu.Unlock()
+		return nil, *p.err.Load()
+	}
+
+	msg := make([]byte, 4+len(req))
+	binary.BigEndian.PutUint32(msg, uint32(len(req)))
+	copy(msg[4:], req)
+	_, werr := p.conn.Write(msg)
+	p.writeMu.Unlock()
+
+	if werr != nil {
+		// The connection is in an undefined state. Close it so the
+		// reader unblocks promptly and triggers shutdown for every
+		// other in-flight caller. NewClient guarantees conn is a
+		// real io.Closer when the pipeline is in use.
+		p.conn.Close()
+		return nil, clientErr(werr)
+	}
+
+	res := <-replyCh
+	return res.reply, res.err
+}
@@ -32,8 +32,10 @@ type keyring struct {

 var errLocked = errors.New("agent: locked")

-// NewKeyring returns an Agent that holds keys in memory.  It is safe
-// for concurrent use by multiple goroutines.
+// NewKeyring returns an Agent that holds keys in memory.  It is safe for
+// concurrent use by multiple goroutines.
+//
+// The returned Agent only supports the "lifetime" constraint.
 func NewKeyring() Agent {
 	return &keyring{}
 }
@@ -143,15 +145,26 @@ func (r *keyring) List() ([]*Key, error) {
 	return ids, nil
 }

-// Insert adds a private key to the keyring. If a certificate
-// is given, that certificate is added as public key. Note that
-// any constraints given are ignored.
+// Add adds a private key to the keyring. If a certificate is given, that
+// certificate is added as public key.
+//
+// Add returns an error if key contains ConstraintExtensions or
+// ConfirmBeforeUse.
 func (r *keyring) Add(key AddedKey) error {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 	if r.locked {
 		return errLocked
 	}
+
+	if key.ConfirmBeforeUse {
+		return errors.New("agent: confirm before use constraint is not supported")
+	}
+
+	if len(key.ConstraintExtensions) > 0 {
+		return errors.New("agent: constraint extensions are present but not supported")
+	}
+
 	signer, err := ssh.NewSignerFromKey(key.PrivateKey)

 	if err != nil {
@@ -240,13 +240,35 @@ func setConstraints(key *AddedKey, constraintBytes []byte) error {
 	return nil
 }

+// checkRSAKeyParams enforces the same bounds as parseRSA in the ssh
+// package, and additionally caps the prime factors. Without this,
+// the rsa.PrivateKey built from an Add request would call Precompute()
+// on arbitrary inputs; the CRT coefficient recomputation is cubic in
+// |p| and can consume excessive CPU on oversized keys.
+func checkRSAKeyParams(N, E, P, Q *big.Int) error {
+	if N.BitLen() > 8192 {
+		return errors.New("agent: RSA modulus too large")
+	}
+	if P.BitLen() > 4096 || Q.BitLen() > 4096 {
+		return errors.New("agent: RSA prime too large")
+	}
+	if E.BitLen() > 24 {
+		return errors.New("agent: RSA public exponent too large")
+	}
+	e := E.Int64()
+	if e < 3 || e&1 == 0 {
+		return errors.New("agent: incorrect RSA public exponent")
+	}
+	return nil
+}
+
 func parseRSAKey(req []byte) (*AddedKey, error) {
 	var k rsaKeyMsg
 	if err := ssh.Unmarshal(req, &k); err != nil {
 		return nil, err
 	}
-	if k.E.BitLen() > 30 {
-		return nil, errors.New("agent: RSA public exponent too large")
+	if err := checkRSAKeyParams(k.N, k.E, k.P, k.Q); err != nil {
+		return nil, err
 	}
 	priv := &rsa.PrivateKey{
 		PublicKey: rsa.PublicKey{
@@ -270,6 +292,9 @@ func parseEd25519Key(req []byte) (*AddedKey, error) {
 	if err := ssh.Unmarshal(req, &k); err != nil {
 		return nil, err
 	}
+	if len(k.Priv) != ed25519.PrivateKeySize {
+		return nil, fmt.Errorf("agent: bad ED25519 key size: %d", len(k.Priv))
+	}
 	priv := ed25519.PrivateKey(k.Priv)

 	addedKey := &AddedKey{PrivateKey: &priv, Comment: k.Comments}
@@ -336,6 +361,9 @@ func parseEd25519Cert(req []byte) (*AddedKey, error) {
 	if err != nil {
 		return nil, err
 	}
+	if len(k.Priv) != ed25519.PrivateKeySize {
+		return nil, fmt.Errorf("agent: bad ED25519 key size: %d", len(k.Priv))
+	}
 	priv := ed25519.PrivateKey(k.Priv)
 	cert, ok := pubKey.(*ssh.Certificate)
 	if !ok {
@@ -393,8 +421,8 @@ func parseRSACert(req []byte) (*AddedKey, error) {
 		return nil, fmt.Errorf("agent: Unmarshal failed to parse public key: %v", err)
 	}

-	if rsaPub.E.BitLen() > 30 {
-		return nil, errors.New("agent: RSA public exponent too large")
+	if err := checkRSAKeyParams(rsaPub.N, rsaPub.E, k.P, k.Q); err != nil {
+		return nil, err
 	}

 	priv := rsa.PrivateKey{
@@ -348,6 +348,9 @@ func (c *CertChecker) CheckHostKey(addr string, remote net.Addr, key PublicKey)
 	if cert.CertType != HostCert {
 		return fmt.Errorf("ssh: certificate presented as a host key has type %d", cert.CertType)
 	}
+	if c.IsHostAuthority == nil {
+		return errors.New("ssh: cannot verify certificate, IsHostAuthority not set")
+	}
 	if !c.IsHostAuthority(cert.SignatureKey, addr) {
 		return fmt.Errorf("ssh: no authorities for hostname: %v", addr)
 	}
@@ -375,6 +378,9 @@ func (c *CertChecker) Authenticate(conn ConnMetadata, pubKey PublicKey) (*Permis
 	if cert.CertType != UserCert {
 		return nil, fmt.Errorf("ssh: cert has type %d", cert.CertType)
 	}
+	if c.IsUserAuthority == nil {
+		return nil, errors.New("ssh: cannot verify certificate, IsUserAuthority not set")
+	}
 	if !c.IsUserAuthority(cert.SignatureKey) {
 		return nil, fmt.Errorf("ssh: certificate signed by unrecognized authority")
 	}
@@ -438,7 +444,17 @@ func (c *CertChecker) CheckCert(principal string, cert *Certificate) error {
 	if before := int64(cert.ValidBefore); cert.ValidBefore != uint64(CertTimeInfinity) && (unixNow >= before || before < 0) {
 		return fmt.Errorf("ssh: cert has expired")
 	}
-	if err := cert.SignatureKey.Verify(cert.bytesForSigning(), cert.Signature); err != nil {
+	// Match OpenSSH: the SK user-presence flag is never enforced on a
+	// certificate's CA signature. OpenSSH calls sshkey_verify with
+	// detailsp==NULL in sshkey.c:cert_parse, so the UP/UV flags are
+	// not even extracted. The UP bit on a CA signature reflects the
+	// CA operator's presence at signing time, which has no bearing on
+	// whether the user being authenticated is present now; enforcing
+	// it here would only break interop with certificates issued by
+	// non-interactive SK CAs. skKeyWithoutUP is a no-op for non-SK
+	// keys (the common case).
+	caKey := skKeyWithoutUP(cert.SignatureKey)
+	if err := caKey.Verify(cert.bytesForSigning(), cert.Signature); err != nil {
 		return fmt.Errorf("ssh: certificate signature does not verify")
 	}

@@ -11,6 +11,7 @@ import (
 	"io"
 	"log"
 	"sync"
+	"sync/atomic"
 )

 const (
@@ -131,11 +132,17 @@ func (r RejectionReason) String() string {
 	return fmt.Sprintf("unknown reason %d", int(r))
 }

-func min(a uint32, b int) uint32 {
-	if a < uint32(b) {
-		return a
+// minPayloadSize returns min(limit, length) clamped to a uint32. It is used
+// to compute the size of the next channel data packet from the remaining
+// payload. The comparison is done in int64 because length is an int — on
+// 64-bit systems len(data) can exceed 2^32, and a direct uint32(length)
+// cast would silently truncate to 0 at every multiple of 2^32, causing
+// WriteExtended's loop to spin without making progress.
+func minPayloadSize(limit uint32, length int) uint32 {
+	if int64(length) > int64(limit) {
+		return limit
 	}
-	return uint32(b)
+	return uint32(length)
 }

 type channelDirection uint8
@@ -177,6 +184,12 @@ type channel struct {
 	// with WantReply=true outstanding.  This lock is held by a
 	// goroutine that has such an outgoing request pending.
 	sentRequestMu sync.Mutex
+	// sentRequestPending is set to true while a SendRequest call with
+	// WantReply=true is in flight. handlePacket uses it as a gate: responses
+	// arriving while no request is pending are dropped to prevent a
+	// misbehaving peer from stalling the mux read loop by filling ch.msg
+	// with unsolicited channelRequestSuccess/Failure messages.
+	sentRequestPending atomic.Bool

 	incomingRequests chan *Request

@@ -251,7 +264,7 @@ func (ch *channel) WriteExtended(data []byte, extendedCode uint32) (n int, err e
 	ch.writeMu.Unlock()

 	for len(data) > 0 {
-		space := min(ch.maxRemotePayload, len(data))
+		space := minPayloadSize(ch.maxRemotePayload, len(data))
 		if space, err = ch.remoteWin.reserve(space); err != nil {
 			return n, err
 		}
@@ -460,6 +473,18 @@ func (ch *channel) handlePacket(packet []byte) error {
 		}

 		ch.incomingRequests <- &req
+	case *channelRequestSuccessMsg, *channelRequestFailureMsg:
+		// Drop responses that arrive when no SendRequest is waiting, to
+		// prevent a malicious peer from filling ch.msg and stalling the
+		// mux read loop. The non-blocking send additionally protects the
+		// loop if a well-behaved caller is slow to read.
+		if !ch.sentRequestPending.Load() {
+			return nil
+		}
+		select {
+		case ch.msg <- msg:
+		default:
+		}
 	default:
 		ch.msg <- msg
 	}
@@ -530,7 +555,17 @@ func (ch *channel) Reject(reason RejectionReason, message string) error {
 		Language: "en",
 	}
 	ch.decided = true
-	return ch.sendMessage(reject)
+	err := ch.sendMessage(reject)
+
+	// Remove the channel from the mux to prevent memory leaks.
+	// Do not call ch.close() here: no goroutine holds a reference to a
+	// rejected channel's internal channels (msg, incomingRequests), so
+	// removing it from chanList is sufficient for GC. Calling close()
+	// would race with the mux loop goroutine (handlePacket or dropAll),
+	// causing a panic from closing an already-closed channel.
+	ch.mux.chanList.remove(ch.localId)
+
+	return err
 }

 func (ch *channel) Read(data []byte) (int, error) {
@@ -586,6 +621,27 @@ func (ch *channel) SendRequest(name string, wantReply bool, payload []byte) (boo
 	if wantReply {
 		ch.sentRequestMu.Lock()
 		defer ch.sentRequestMu.Unlock()
+
+		// Open the gate so that responses arriving while this request is in
+		// flight are allowed to reach ch.msg. Responses arriving while no
+		// request is pending are dropped by handlePacket.
+		ch.sentRequestPending.Store(true)
+		defer ch.sentRequestPending.Store(false)
+
+		// Drain any spurious responses that may have been buffered. This
+		// prevents a previously buffered unexpected response from being
+		// consumed instead of the actual response for this request.
+	drain:
+		for {
+			select {
+			case _, ok := <-ch.msg:
+				if !ok {
+					break drain
+				}
+			default:
+				break drain
+			}
+		}
 	}

 	msg := channelRequestMsg{
@@ -407,7 +407,7 @@ func (c *gcmCipher) readCipherPacket(seqNum uint32, r io.Reader) ([]byte, error)
 		return nil, fmt.Errorf("ssh: illegal padding %d", padding)
 	}

-	if int(padding+1) >= len(plain) {
+	if int(padding)+1 >= len(plain) {
 		return nil, fmt.Errorf("ssh: padding %d too large", padding)
 	}
 	plain = plain[1 : length-uint32(padding)]
@@ -88,6 +88,32 @@ func NewClientConn(c net.Conn, addr string, config *ClientConfig) (Conn, <-chan
 	return conn, conn.mux.incomingChannels, conn.mux.incomingRequests, nil
 }

+// NewControlClientConn establishes an SSH connection over an OpenSSH
+// ControlMaster socket c in proxy mode.
+//
+// Note that this package only implements the client side of the multiplexing
+// protocol. The provided net.Conn must be a local, secure connection (such as a
+// Unix domain socket) connected to an already-running OpenSSH process acting as
+// the ControlMaster.
+//
+// WARNING: Because proxy mode bypasses the standard cryptographic handshake
+// passing a standard network connection (e.g., TCP) will result in plaintext
+// data leakage.
+//
+// The Request and NewChannel channels must be serviced or the connection
+// will hang.
+func NewControlClientConn(c net.Conn) (Conn, <-chan NewChannel, <-chan *Request, error) {
+	conn := &connection{
+		sshConn: sshConn{conn: c},
+	}
+	var err error
+	if conn.transport, err = handshakeControlProxy(c); err != nil {
+		return nil, nil, nil, fmt.Errorf("ssh: control proxy handshake failed: %w", err)
+	}
+	conn.mux = newMux(conn.transport)
+	return conn, conn.mux.incomingChannels, conn.mux.incomingRequests, nil
+}
+
 // clientHandshake performs the client side key exchange. See RFC 4253 Section
 // 7.
 func (c *connection) clientHandshake(dialAddress string, config *ClientConfig) error {
@@ -197,6 +223,59 @@ type HostKeyCallback func(hostname string, remote net.Addr, key PublicKey) error
 // the server. A BannerCallback receives the message sent by the remote server.
 type BannerCallback func(message string) error

+// ClientAuthContext contains information about the current state of the
+// authentication process, passed to [ClientAuthCallback].
+type ClientAuthContext struct {
+	// Metadata contains the connection metadata.
+	Metadata ConnMetadata
+
+	// Algorithms contains the negotiated algorithms.
+	Algorithms NegotiatedAlgorithms
+
+	// AllowedMethods lists the authentication methods currently accepted
+	// by the server. These are the protocol-level names defined in RFC 4252
+	// such as "publickey", "password".
+	AllowedMethods []string
+
+	// PartialSuccessMethods lists the authentication methods that have already
+	// succeeded, indicating a multi-step authentication flow. This list
+	// represents the exact sequence of partial successes and may contain
+	// duplicates if the same method succeeded multiple times.
+	PartialSuccessMethods []string
+
+	// TriedMethods lists the methods that have already been attempted and
+	// failed during this session. This list represents the exact sequence of
+	// failures and may contain duplicates. This allows the callback to also
+	// track the number of failed attempts for a specific method.
+	TriedMethods []string
+}
+
+// ClientAuthCallback is a hook invoked before each authentication attempt. It
+// allows the client to dynamically select an authentication method based on the
+// current context, server capabilities, or previous failures.
+//
+// The callback is invoked after the initial "none" authentication method, once
+// the server's supported authentication methods are known.
+//
+// Return values:
+//   - (AuthMethod, nil): The client will attempt this specific method next.
+//     The returned method does NOT need to be present in [ClientConfig.Auth].
+//     This allows for dynamic authentication strategies (e.g., prompting
+//     for a password only if public key auth fails). Callers should inspect
+//     [ClientAuthContext.TriedMethods] to avoid repeatedly returning the
+//     same failing method.
+//   - (nil, nil): The client selects from [ClientConfig.Auth] the first
+//     instance of a method that has not been tried yet, or aborts if none
+//     are left. If authentication is not successful, the callback is invoked
+//     again before the following attempt.
+//   - (nil, error): The authentication process is aborted immediately,
+//     causing the ongoing SSH handshake to fail with the provided error.
+//
+// To bound resource use, the client caps the total number of authentication
+// attempts (failures and partial successes combined) at 64. If the cap is
+// exceeded the handshake aborts with an error.
+type ClientAuthCallback func(ctx *ClientAuthContext) (AuthMethod, error)
+
 // A ClientConfig structure is used to configure a Client. It must not be
 // modified after having been passed to an SSH function.
 type ClientConfig struct {
@@ -210,6 +289,9 @@ type ClientConfig struct {
 	// Auth contains possible authentication methods to use with the
 	// server. Only the first instance of a particular RFC 4252 method will
 	// be used during authentication.
+	//
+	// If AuthCallback is set, these AuthMethod are only used if the
+	// callback returns nil.
 	Auth []AuthMethod

 	// HostKeyCallback is called during the cryptographic
@@ -240,6 +322,9 @@ type ClientConfig struct {
 	//
 	// A Timeout of zero means no timeout.
 	Timeout time.Duration
+
+	// AuthCallback, if non-nil, is invoked before each authentication attempt.
+	AuthCallback ClientAuthCallback
 }

 // InsecureIgnoreHostKey returns a function that can be used for
@@ -21,6 +21,12 @@ const (
 	authSuccess
 )

+// maxAuthClientTried bounds the total number of authentication attempts
+// (failures and partial successes combined) the client makes before
+// aborting the loop, to prevent unbounded growth when an AuthCallback
+// keeps supplying methods.
+const maxAuthClientTried = 64
+
 // clientAuthenticate authenticates with the remote server. See RFC 4252.
 func (c *connection) clientAuthenticate(config *ClientConfig) error {
 	// initiate user auth session
@@ -67,32 +73,62 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
 	// then any untried methods suggested by the server.
 	var tried []string
 	var lastMethods []string
+	var partialSuccess []string

 	sessionID := c.transport.getSessionID()
 	for auth := AuthMethod(new(noneAuth)); auth != nil; {
 		ok, methods, err := auth.auth(sessionID, config.User, c.transport, config.Rand, extensions)
 		if err != nil {
 			// On disconnect, return error immediately
-			if _, ok := err.(*disconnectMsg); ok {
+			if _, isDisconnect := err.(*disconnectMsg); isDisconnect {
 				return err
 			}
-			// We return the error later if there is no other method left to
-			// try.
+			// We return the error later if there is no other method
+			// left to try.
 			ok = authFailure
 		}
-		if ok == authSuccess {
-			// success
+
+		switch ok {
+		case authSuccess:
 			return nil
-		} else if ok == authFailure {
-			if m := auth.method(); !slices.Contains(tried, m) {
-				tried = append(tried, m)
-			}
+		case authPartialSuccess:
+			partialSuccess = append(partialSuccess, auth.method())
+		case authFailure:
+			tried = append(tried, auth.method())
 		}
+		if len(partialSuccess)+len(tried) > maxAuthClientTried {
+			return fmt.Errorf("ssh: too many authentication attempts (%d), aborting",
+				len(partialSuccess)+len(tried))
+		}
+
 		if methods == nil {
 			methods = lastMethods
 		}
 		lastMethods = methods

+		// If AuthCallback is set it takes precedence: it picks the next
+		// AuthMethod dynamically. The returned method need not be in
+		// config.Auth. If the callback returns (nil, nil) we fall back to
+		// selecting the next untried method from config.Auth below; on
+		// (nil, error) the handshake aborts.
+		if config.AuthCallback != nil {
+			ctx := &ClientAuthContext{
+				Metadata:              c,
+				Algorithms:            c.Algorithms(),
+				AllowedMethods:        slices.Clone(methods),
+				PartialSuccessMethods: slices.Clone(partialSuccess),
+				TriedMethods:          slices.Clone(tried),
+			}
+			altAuth, cbErr := config.AuthCallback(ctx)
+			if cbErr != nil {
+				return cbErr
+			}
+			if altAuth != nil {
+				auth = altAuth
+				continue
+			}
+		}
+
 		auth = nil

 	findNext:
@@ -377,11 +413,11 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
 			return authFailure, nil, err
 		}

-		// If authentication succeeds or the list of available methods does not
-		// contain the "publickey" method, do not attempt to authenticate with any
-		// other keys.  According to RFC 4252 Section 7, the latter can occur when
-		// additional authentication methods are required.
-		if success == authSuccess || !slices.Contains(methods, cb.method()) {
+		// If authentication succeeds or partially succeeds, return immediately
+		// so the caller can select the next auth method. According to RFC 4252
+		// Section 7, if the server no longer lists "publickey" among its
+		// allowed methods, do not attempt to authenticate with any other keys.
+		if success == authSuccess || success == authPartialSuccess || !slices.Contains(methods, cb.method()) {
 			return success, methods, err
 		}
 	}
@@ -91,9 +91,17 @@ func DiscardRequests(in <-chan *Request) {
 	}
 }

+// A connTransport represents the transport for a connection.
+type connTransport interface {
+	packetConn
+	getAlgorithms() NegotiatedAlgorithms
+	getSessionID() []byte
+	waitSession() error
+}
+
 // A connection represents an incoming connection.
 type connection struct {
-	transport *handshakeTransport
+	transport connTransport
 	sshConn

 	// The connection protocol.
@@ -0,0 +1,155 @@
+// Copyright 2026 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+
+	"golang.org/x/crypto/cryptobyte"
+)
+
+const (
+	muxProtocolVersion = 4
+
+	muxMsgHello = 0x00000001
+	muxCProxy   = 0x1000000f
+	muxSProxy   = 0x8000000f
+)
+
+const controlProxyRequestID = 0
+
+// handshakeControlProxy attempts to establish a transport connection with an
+// OpenSSH ControlMaster socket in proxy mode. For details see:
+// https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.mux
+func handshakeControlProxy(rw io.ReadWriteCloser) (connTransport, error) {
+	if err := controlProxyWritePacket(rw, func(b *cryptobyte.Builder) {
+		b.AddUint32(muxMsgHello)
+		b.AddUint32(muxProtocolVersion)
+	}); err != nil {
+		return nil, fmt.Errorf("mux hello write failed: %w", err)
+	}
+	if err := controlProxyWritePacket(rw, func(b *cryptobyte.Builder) {
+		b.AddUint32(muxCProxy)
+		b.AddUint32(controlProxyRequestID)
+	}); err != nil {
+		return nil, fmt.Errorf("mux client proxy write failed: %w", err)
+	}
+
+	messageType, body, err := controlProxyReadMessage(rw)
+	if err != nil {
+		return nil, fmt.Errorf("mux hello read failed: %w", err)
+	}
+	if messageType != muxMsgHello {
+		return nil, fmt.Errorf("expected hello response, got %v", messageType)
+	}
+	var v uint32
+	if !body.ReadUint32(&v) {
+		return nil, errors.New("EOF reading mux protocol version")
+	}
+	if v != muxProtocolVersion {
+		return nil, fmt.Errorf("mux server has unsupported version %v", v)
+	}
+	messageType, body, err = controlProxyReadMessage(rw)
+	if err != nil {
+		return nil, fmt.Errorf("mux server proxy read failed: %w", err)
+	}
+	if messageType != muxSProxy {
+		return nil, fmt.Errorf("expected server proxy response, got %v", messageType)
+	}
+	var reqID uint32
+	if !body.ReadUint32(&reqID) {
+		return nil, errors.New("EOF reading request id")
+	}
+	if reqID != controlProxyRequestID {
+		return nil, fmt.Errorf("expected request id %v, got %v", controlProxyRequestID, reqID)
+	}
+	return &controlProxyTransport{rw}, nil
+}
+
+// controlProxyTransport implements the connTransport interface for
+// ControlMaster connections. Each controlMessage has zero length padding and
+// no MAC.
+type controlProxyTransport struct {
+	rw io.ReadWriteCloser
+}
+
+func (p *controlProxyTransport) Close() error {
+	return p.rw.Close()
+}
+
+func (p *controlProxyTransport) writePacket(controlMessage []byte) error {
+	return controlProxyWritePacket(p.rw, func(b *cryptobyte.Builder) {
+		b.AddUint8(0) // Padding length.
+		b.AddBytes(controlMessage)
+	})
+}
+
+func (p *controlProxyTransport) readPacket() ([]byte, error) {
+	buf, err := controlProxyReadPacket(p.rw)
+	if err != nil {
+		return nil, fmt.Errorf("ssh: error reading control message: %w", err)
+	}
+	// Discard the padding length.
+	if len(buf) < 1 {
+		return nil, errors.New("ssh: EOF reading padding length")
+	}
+	if buf[0] != 0 {
+		return nil, errors.New("ssh: unexpected non-zero padding in control message")
+	}
+	return buf[1:], nil
+}
+
+func (p *controlProxyTransport) getAlgorithms() NegotiatedAlgorithms {
+	return NegotiatedAlgorithms{}
+}
+
+func (p *controlProxyTransport) getSessionID() []byte {
+	return nil
+}
+
+func (p *controlProxyTransport) waitSession() error {
+	return nil
+}
+
+func controlProxyWritePacket(w io.Writer, f cryptobyte.BuilderContinuation) error {
+	var buf []byte
+	b := cryptobyte.NewBuilder(buf)
+	b.AddUint32LengthPrefixed(f)
+	out, err := b.Bytes()
+	if err != nil {
+		return err
+	}
+	_, err = w.Write(out)
+	return err
+}
+
+func controlProxyReadPacket(r io.Reader) (cryptobyte.String, error) {
+	var l uint32
+	if err := binary.Read(r, binary.BigEndian, &l); err != nil {
+		return nil, err
+	}
+	if l > maxPacket {
+		return nil, fmt.Errorf("message length %v exceeds maximum %v", l, maxPacket)
+	}
+	buf := make([]byte, l)
+	if _, err := io.ReadFull(r, buf); err != nil {
+		return nil, err
+	}
+	return buf, nil
+}
+
+func controlProxyReadMessage(r io.Reader) (messageType uint32, body cryptobyte.String, err error) {
+	body, err = controlProxyReadPacket(r)
+	if err != nil {
+		return 0, nil, fmt.Errorf("error reading message body: %w", err)
+	}
+	if !body.ReadUint32(&messageType) {
+		return 0, nil, errors.New("EOF reading message type")
+	}
+	return messageType, body, nil
+}
@@ -16,6 +16,7 @@ import (
 	"io"
 	"math/big"
 	"slices"
+	"sync"

 	"golang.org/x/crypto/curve25519"
 )
@@ -718,15 +719,9 @@ func (gex *dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshak
 			kexDHGexRequest.MaxBits, kexDHGexRequest.PreferredBits)
 	}

-	var p *big.Int
-	// We hardcode sending Oakley Group 14 (2048 bits), Oakley Group 15 (3072
-	// bits) or Oakley Group 16 (4096 bits), based on the requested max size.
-	if kexDHGexRequest.MaxBits < 3072 {
-		p, _ = new(big.Int).SetString(oakleyGroup14, 16)
-	} else if kexDHGexRequest.MaxBits < 4096 {
-		p, _ = new(big.Int).SetString(oakleyGroup15, 16)
-	} else {
-		p, _ = new(big.Int).SetString(oakleyGroup16, 16)
+	p, err := chooseDH(kexDHGexRequest)
+	if err != nil {
+		return nil, err
 	}

 	g := big.NewInt(2)
@@ -805,3 +800,65 @@ func (gex *dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshak
 		Hash:      gex.hashFunc,
 	}, err
 }
+
+type dhKEXGroup struct {
+	size int
+	p    *big.Int
+}
+
+// supportedDHKEXGroups returns the DH groups the server is willing to offer
+// for diffie-hellman-group-exchange-* key exchanges. The list is built lazily
+// on first use to keep the hex-to-big.Int parse out of package initialization.
+var supportedDHKEXGroups = sync.OnceValue(func() []dhKEXGroup {
+	specs := []struct {
+		size int
+		hex  string
+	}{
+		{2048, oakleyGroup14},
+		{3072, oakleyGroup15},
+		{4096, oakleyGroup16},
+	}
+	out := make([]dhKEXGroup, 0, len(specs))
+	for _, s := range specs {
+		p, _ := new(big.Int).SetString(s.hex, 16)
+		out = append(out, dhKEXGroup{size: s.size, p: p})
+	}
+	return out
+})
+
+// chooseDH picks a DH group for the given client request, mirroring the
+// algorithm used by OpenSSH's choose_dh in dh.c: prefer the smallest known
+// group larger than  or equal to the client's PreferredBits, and otherwise pick
+// the largest group within the accepted [MinBits, MaxBits] range.
+func chooseDH(req kexDHGexRequestMsg) (*big.Int, error) {
+	var best *big.Int
+	bestSize := 0
+	wantBits := int(req.PreferredBits)
+
+	for _, group := range supportedDHKEXGroups() {
+		if uint32(group.size) < req.MinBits || uint32(group.size) > req.MaxBits {
+			continue
+		}
+
+		if bestSize == 0 {
+			best = group.p
+			bestSize = group.size
+			continue
+		}
+
+		closerFromAbove := group.size >= wantBits && group.size < bestSize
+		closerFromBelow := group.size > bestSize && bestSize < wantBits
+
+		if closerFromAbove || closerFromBelow {
+			best = group.p
+			bestSize = group.size
+		}
+	}
+
+	if bestSize == 0 {
+		return nil, fmt.Errorf("ssh: no suitable DH group found for request min: %d, preferred: %d, max: %d",
+			req.MinBits, req.PreferredBits, req.MaxBits)
+	}
+
+	return best, nil
+}
@@ -76,7 +76,7 @@ func parsePubKey(in []byte, algo string) (pubKey PublicKey, rest []byte, err err
 	case InsecureKeyAlgoDSA:
 		return parseDSA(in)
 	case KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521:
-		return parseECDSA(in)
+		return parseECDSA(in, algo)
 	case KeyAlgoSKECDSA256:
 		return parseSKECDSA(in)
 	case KeyAlgoED25519:
@@ -469,6 +469,12 @@ func parseRSA(in []byte) (out PublicKey, rest []byte, err error) {
 		return nil, nil, err
 	}

+	// 8192 bits is also the maximum RSA key size accepted by crypto/tls for
+	// signature verification:
+	// https://github.com/golang/go/blob/69801b25/src/crypto/tls/handshake_client.go#L1096
+	if w.N.BitLen() > 8192 {
+		return nil, nil, errors.New("ssh: rsa modulus too large")
+	}
 	if w.E.BitLen() > 24 {
 		return nil, nil, errors.New("ssh: exponent too large")
 	}
@@ -574,6 +580,24 @@ func checkDSAParams(param *dsa.Parameters) error {
 		return fmt.Errorf("ssh: unsupported DSA key size %d", l)
 	}

+	// FIPS 186-2 specifies that Q must be exactly 160 bits. We must enforce
+	// this to prevent DoS attacks where an attacker sends a huge Q which makes
+	// verification slow.
+	if l := param.Q.BitLen(); l != 160 {
+		return fmt.Errorf("ssh: unsupported DSA sub-prime size %d", l)
+	}
+
+	// The generator G is an element of the group, so it must be strictly less
+	// than the modulus P.
+	if param.G.Cmp(param.P) >= 0 {
+		return errors.New("ssh: DSA generator larger than modulus")
+	}
+
+	// G must be positive.
+	if param.G.Sign() <= 0 {
+		return errors.New("ssh: DSA generator must be positive")
+	}
+
 	return nil
 }

@@ -596,6 +620,14 @@ func parseDSA(in []byte) (out PublicKey, rest []byte, err error) {
 		return nil, nil, err
 	}

+	// The public value Y must be a non-zero element of the group, i.e.
+	// strictly between 0 and P. crypto/dsa.Verify does not range-check Y,
+	// so we reject out-of-range values here to prevent a maliciously
+	// oversized Y from slowing verification.
+	if w.Y.Sign() <= 0 || w.Y.Cmp(w.P) >= 0 {
+		return nil, nil, errors.New("ssh: DSA public value Y out of range")
+	}
+
 	key := &dsaPublicKey{
 		Parameters: param,
 		Y:          w.Y,
@@ -774,7 +806,7 @@ func supportedEllipticCurve(curve elliptic.Curve) bool {
 }

 // parseECDSA parses an ECDSA key according to RFC 5656, section 3.1.
-func parseECDSA(in []byte) (out PublicKey, rest []byte, err error) {
+func parseECDSA(in []byte, expectedType string) (out PublicKey, rest []byte, err error) {
 	var w struct {
 		Curve    string
 		KeyBytes []byte
@@ -785,6 +817,12 @@ func parseECDSA(in []byte) (out PublicKey, rest []byte, err error) {
 		return nil, nil, err
 	}

+	actualType := "ecdsa-sha2-" + w.Curve
+	if expectedType != actualType {
+		return nil, nil, fmt.Errorf("ssh: algorithm type mismatch: expected %q, found curve %q (type %q)",
+			expectedType, w.Curve, actualType)
+	}
+
 	key := new(ecdsa.PublicKey)

 	switch w.Curve {
@@ -869,11 +907,25 @@ type skFields struct {
 	Counter uint32
 }

+// flagUserPresence is the "user present" bit (UP) in the SK signature
+// flags, matching the FIDO CTAP2 authenticatorData UP flag. See
+// openssh/PROTOCOL.u2f.
+const flagUserPresence = 0x01
+
+// errSKMissingUserPresence is returned by SK key Verify methods when
+// the signature does not assert user presence and the key was not
+// marked as no-touch-required.
+var errSKMissingUserPresence = errors.New("ssh: signature missing required user presence flag")
+
 type skECDSAPublicKey struct {
 	// application is a URL-like string, typically "ssh:" for SSH.
 	// see openssh/PROTOCOL.u2f for details.
 	application string
 	ecdsa.PublicKey
+	// noTouchRequired, when true, disables the default user-presence
+	// check in Verify. It is set by skKeyWithoutUP on a clone of the
+	// key, never on an instance shared across authentication attempts.
+	noTouchRequired bool
 }

 func (k *skECDSAPublicKey) Type() string {
@@ -959,6 +1011,10 @@ func (k *skECDSAPublicKey) Verify(data []byte, sig *Signature) error {
 		return err
 	}

+	if skf.Flags&flagUserPresence == 0 && !k.noTouchRequired {
+		return errSKMissingUserPresence
+	}
+
 	blob := struct {
 		ApplicationDigest []byte `ssh:"rest"`
 		Flags             byte
@@ -992,6 +1048,10 @@ type skEd25519PublicKey struct {
 	// see openssh/PROTOCOL.u2f for details.
 	application string
 	ed25519.PublicKey
+	// noTouchRequired, when true, disables the default user-presence
+	// check in Verify. It is set by skKeyWithoutUP on a clone of the
+	// key, never on an instance shared across authentication attempts.
+	noTouchRequired bool
 }

 func (k *skEd25519PublicKey) Type() string {
@@ -1066,6 +1126,10 @@ func (k *skEd25519PublicKey) Verify(data []byte, sig *Signature) error {
 		return err
 	}

+	if skf.Flags&flagUserPresence == 0 && !k.noTouchRequired {
+		return errSKMissingUserPresence
+	}
+
 	blob := struct {
 		ApplicationDigest []byte `ssh:"rest"`
 		Flags             byte
@@ -1408,6 +1472,17 @@ func passphraseProtectedOpenSSHKey(passphrase []byte) openSSHDecryptFunc {
 			return nil, err
 		}

+		// OpenSSH does not impose an upper bound on the bcrypt round count
+		// stored in the key file, but bcrypt_pbkdf cost is linear in rounds:
+		// the default is 16, ssh-keygen lets users pick anything up to
+		// INT_MAX. Cap at 2048 (128x the default, a few seconds of CPU) so
+		// that an oversized value in the file cannot tie up the caller for
+		// months.
+		const maxRounds = 1 << 11
+		if opts.Rounds > maxRounds {
+			return nil, fmt.Errorf("ssh: bcrypt KDF rounds %d exceed maximum %d", opts.Rounds, maxRounds)
+		}
+
 		k, err := bcrypt_pbkdf.Key(passphrase, []byte(opts.Salt), int(opts.Rounds), 32+16)
 		if err != nil {
 			return nil, err
@@ -1577,10 +1652,28 @@ func parseOpenSSHPrivateKey(key []byte, decrypt openSSHDecryptFunc) (crypto.Priv
 			return nil, err
 		}

+		// Mirror the validation done in parseRSA for public keys: cap the
+		// modulus at the same limit enforced by crypto/tls, reject oversized
+		// or invalid exponents, and additionally bound the prime factors to
+		// avoid the expensive CRT coefficient recomputation in pk.Precompute.
+		if key.N.BitLen() > 8192 {
+			return nil, errors.New("ssh: rsa modulus too large")
+		}
+		if key.P.BitLen() > 4096 || key.Q.BitLen() > 4096 {
+			return nil, errors.New("ssh: rsa prime too large")
+		}
+		if key.E.BitLen() > 24 {
+			return nil, errors.New("ssh: exponent too large")
+		}
+		e := key.E.Int64()
+		if e < 3 || e&1 == 0 {
+			return nil, errors.New("ssh: incorrect exponent")
+		}
+
 		pk := &rsa.PrivateKey{
 			PublicKey: rsa.PublicKey{
 				N: key.N,
-				E: int(key.E.Int64()),
+				E: int(e),
 			},
 			D:      key.D,
 			Primes: []*big.Int{key.P, key.Q},
@@ -160,8 +160,13 @@ func (db *hostKeyDB) IsHostAuthority(remote ssh.PublicKey, address string) bool

 // IsRevoked can be used as a callback in ssh.CertChecker
 func (db *hostKeyDB) IsRevoked(key *ssh.Certificate) bool {
-	_, ok := db.revoked[string(key.Marshal())]
-	return ok
+	if _, ok := db.revoked[string(key.Marshal())]; ok {
+		return true
+	}
+	if _, ok := db.revoked[string(key.SignatureKey.Marshal())]; ok {
+		return true
+	}
+	return false
 }

 const markerCert = "@cert-authority"
@@ -173,7 +178,7 @@ func nextWord(line []byte) (string, []byte) {
 		return string(line), nil
 	}

-	return string(line[:i]), bytes.TrimSpace(line[i:])
+	return string(line[:i]), trimSpace(line[i:])
 }

 func parseLine(line []byte) (marker, host string, key ssh.PublicKey, err error) {
@@ -183,12 +188,17 @@ func parseLine(line []byte) (marker, host string, key ssh.PublicKey, err error)
 	}

 	host, line = nextWord(line)
+	// If the extracted 'host' starts with '@', it means we either encountered
+	// a second marker (e.g., "@cert-authority @revoked") or an unknown marker
+	// (e.g., "@unknown"). Both are invalid.
+	if len(host) > 0 && host[0] == '@' {
+		return "", "", nil, fmt.Errorf("knownhosts: unexpected marker: %q", host)
+	}
 	if len(line) == 0 {
 		return "", "", nil, errors.New("knownhosts: missing host pattern")
 	}

-	// ignore the keytype as it's in the key blob anyway.
-	_, line = nextWord(line)
+	wantType, line := nextWord(line)
 	if len(line) == 0 {
 		return "", "", nil, errors.New("knownhosts: missing key type pattern")
 	}
@@ -204,6 +214,10 @@ func parseLine(line []byte) (marker, host string, key ssh.PublicKey, err error)
 		return "", "", nil, err
 	}

+	if key.Type() != wantType {
+		return "", "", nil, fmt.Errorf("knownhosts: key type mismatch: found %q, want %q", key.Type(), wantType)
+	}
+
 	return marker, host, key, nil
 }

@@ -382,7 +396,7 @@ func (db *hostKeyDB) Read(r io.Reader, filename string) error {
 	for scanner.Scan() {
 		lineNum++
 		line := scanner.Bytes()
-		line = bytes.TrimSpace(line)
+		line = trimSpace(line)
 		if len(line) == 0 || line[0] == '#' {
 			continue
 		}
@@ -530,3 +544,10 @@ func newHashedHost(encoded string) (*hashedHost, error) {
 func (h *hashedHost) match(a addr) bool {
 	return bytes.Equal(hashHost(Normalize(a.String()), h.salt), h.hash)
 }
+
+// trimSpace removes leading and trailing ASCII whitespace (space and tab). It
+// is used instead of bytes.TrimSpace to match OpenSSH behavior, which strictly
+// parses only ASCII space (0x20) and tab (0x09) as whitespace.
+func trimSpace(in []byte) []byte {
+	return bytes.Trim(in, " \t")
+}
@@ -91,9 +91,10 @@ type mux struct {

 	incomingChannels chan NewChannel

-	globalSentMu     sync.Mutex
-	globalResponses  chan interface{}
-	incomingRequests chan *Request
+	globalSentMu      sync.Mutex
+	globalSentPending atomic.Bool
+	globalResponses   chan interface{}
+	incomingRequests  chan *Request

 	errCond *sync.Cond
 	err     error
@@ -141,6 +142,27 @@ func (m *mux) SendRequest(name string, wantReply bool, payload []byte) (bool, []
 	if wantReply {
 		m.globalSentMu.Lock()
 		defer m.globalSentMu.Unlock()
+
+		// Open the gate so that responses arriving while this request is in
+		// flight are allowed to reach globalResponses. Any response arriving
+		// while no request is pending is dropped by handleGlobalPacket.
+		m.globalSentPending.Store(true)
+		defer m.globalSentPending.Store(false)
+
+		// Drain any spurious responses that may have been buffered. This prevents
+		// a previously buffered unexpected response from being consumed instead
+		// of the actual response for this request.
+	drain:
+		for {
+			select {
+			case _, ok := <-m.globalResponses:
+				if !ok {
+					break drain
+				}
+			default:
+				break drain
+			}
+		}
 	}

 	if err := m.sendMessage(globalRequestMsg{
@@ -267,7 +289,16 @@ func (m *mux) handleGlobalPacket(packet []byte) error {
 			mux:       m,
 		}
 	case *globalRequestSuccessMsg, *globalRequestFailureMsg:
-		m.globalResponses <- msg
+		// Drop responses that arrive when no SendRequest is waiting, to
+		// prevent a malicious peer from staging responses for a future
+		// caller.
+		if !m.globalSentPending.Load() {
+			return nil
+		}
+		select {
+		case m.globalResponses <- msg:
+		default:
+		}
 	default:
 		panic(fmt.Sprintf("not a global message %#v", msg))
 	}
@@ -34,21 +34,29 @@ type Permissions struct {
 	// or not supported.
 	CriticalOptions map[string]string

-	// Extensions are extra functionality that the server may
-	// offer on authenticated connections. Lack of support for an
-	// extension does not preclude authenticating a user. Common
-	// extensions are "permit-agent-forwarding",
-	// "permit-X11-forwarding". The Go SSH library currently does
-	// not act on any extension, and it is up to server
-	// implementations to honor them. Extensions can be used to
-	// pass data from the authentication callbacks to the server
-	// application layer.
+	// Extensions are extra functionality that the server may offer on
+	// authenticated connections. Lack of support for an extension does not
+	// preclude authenticating a user. Common extensions are
+	// "permit-agent-forwarding", "permit-X11-forwarding". In general the Go
+	// SSH library does not act on extensions and it is up to server
+	// implementations to honor them; extensions can also be used to pass data
+	// from the authentication callbacks to the server application layer.
+	//
+	// The one extension acted upon by this library is "no-touch-required",
+	// which applies only to security-key public keys
+	// (sk-ecdsa-sha2-nistp256@openssh.com and sk-ssh-ed25519@openssh.com).
+	// When present, it waives the default requirement that SK signatures
+	// assert user presence (i.e. a physical touch of the authenticator)
+	// during signature verification.
 	Extensions map[string]string

 	// ExtraData allows to store user defined data.
 	ExtraData map[any]any
 }

+// GSSAPIWithMICConfig includes the server callbacks for gssapi-with-mic
+// authentication. If either field is nil, gssapi-with-mic is considered not
+// configured.
 type GSSAPIWithMICConfig struct {
 	// AllowLogin, must be set, is called when gssapi-with-mic
 	// authentication is selected (RFC 4462 section 3). The srcName is from the
@@ -63,6 +71,10 @@ type GSSAPIWithMICConfig struct {
 	Server GSSAPIServer
 }

+func gssapiWithMICConfigured(config *GSSAPIWithMICConfig) bool {
+	return config != nil && config.AllowLogin != nil && config.Server != nil
+}
+
 // SendAuthBanner implements [ServerPreAuthConn].
 func (s *connection) SendAuthBanner(msg string) error {
 	return s.transport.writePacket(Marshal(&userAuthBannerMsg{
@@ -84,6 +96,79 @@ type ServerPreAuthConn interface {
 	SendAuthBanner(string) error
 }

+// noTouchRequiredExtension is the extension name used by OpenSSH in
+// authorized_keys options and certificate extensions to mark keys
+// whose signatures do not need to assert user presence (touch). See
+// ssh-keygen(1) and sshd(8).
+const noTouchRequiredExtension = "no-touch-required"
+
+// noTouchAllowed reports whether the user presence requirement on
+// SK signatures should be waived for this authentication attempt. The
+// requirement is waived when the "no-touch-required" extension is
+// present either in the Permissions returned by the auth callback
+// (authorized_keys-level opt-out) or in the certificate's own
+// Extensions (CA-level opt-out), matching OpenSSH behavior. OpenSSH
+// reads the per-key opt-out only from cert Extensions and
+// authorized_keys options (never from CriticalOptions); we follow the
+// same rule.
+func noTouchAllowed(pubKey PublicKey, perms *Permissions) bool {
+	if perms != nil {
+		if _, ok := perms.Extensions[noTouchRequiredExtension]; ok {
+			return true
+		}
+	}
+	if cert, ok := pubKey.(*Certificate); ok {
+		if _, ok := cert.Extensions[noTouchRequiredExtension]; ok {
+			return true
+		}
+	}
+	return false
+}
+
+// skKeyWithoutUP returns a PublicKey equivalent to pubKey but whose
+// Verify accepts SK signatures with the user-presence flag clear. If
+// pubKey is not (and does not wrap) an SK key, pubKey is returned
+// unchanged. The returned value never mutates pubKey: for SK keys a
+// shallow copy is made so that the noTouchRequired flag is set only on
+// the clone.
+//
+// The implementation is iterative rather than recursive. When pubKey
+// is a *Certificate we unwrap exactly one level to look at the inner
+// key. The SSH cert format forbids Certificate.Key from being another
+// Certificate (parseCert rejects it), but nothing stops callers from
+// constructing such a value directly in Go; a recursive descent could
+// otherwise be driven to unbounded depth by a hand-crafted or cyclic
+// Certificate. A malformed input of that shape simply returns
+// unchanged here.
+func skKeyWithoutUP(pubKey PublicKey) PublicKey {
+	cert, isCert := pubKey.(*Certificate)
+	target := pubKey
+	if isCert {
+		target = cert.Key
+	}
+	var cloned PublicKey
+	switch k := target.(type) {
+	case *skECDSAPublicKey:
+		c := *k
+		c.noTouchRequired = true
+		cloned = &c
+	case *skEd25519PublicKey:
+		c := *k
+		c.noTouchRequired = true
+		cloned = &c
+	default:
+		// Not an SK key (or a pathological *Certificate wrapping
+		// another *Certificate): pubKey is already usable for Verify.
+		return pubKey
+	}
+	if !isCert {
+		return cloned
+	}
+	c := *cert
+	c.Key = cloned
+	return &c
+}
+
 // ServerConfig holds server specific configuration data.
 type ServerConfig struct {
 	// Config contains configuration shared between client and server.
@@ -242,8 +327,10 @@ func (c *pubKeyCache) add(candidate cachedPubKey) {
 type ServerConn struct {
 	Conn

-	// If the succeeding authentication callback returned a
-	// non-nil Permissions pointer, it is stored here.
+	// If the succeeding authentication callback returned a non-nil Permissions
+	// pointer, it is stored here. These are the permissions from the final,
+	// successful authentication method. Permissions returned by callbacks that
+	// return PartialSuccessError are not preserved and must be nil.
 	Permissions *Permissions
 }

@@ -302,8 +389,7 @@ func (s *connection) serverHandshake(config *ServerConfig) (*Permissions, error)
 	}

 	if !config.NoClientAuth && config.PasswordCallback == nil && config.PublicKeyCallback == nil &&
-		config.KeyboardInteractiveCallback == nil && (config.GSSAPIWithMICConfig == nil ||
-		config.GSSAPIWithMICConfig.AllowLogin == nil || config.GSSAPIWithMICConfig.Server == nil) {
+		config.KeyboardInteractiveCallback == nil && !gssapiWithMICConfigured(config.GSSAPIWithMICConfig) {
 		return nil, errors.New("ssh: no authentication methods configured but NoClientAuth is also false")
 	}

@@ -527,6 +613,15 @@ func (b *BannerError) Error() string {
 	return b.Err.Error()
 }

+// maxAuthServerAttempts caps the total number of SSH_MSG_USERAUTH_REQUEST
+// messages the server will process on a single connection, regardless of
+// outcome (failure, partial success, public key query, or none). It is a
+// backstop against clients that drive the authentication loop indefinitely
+// without ever incurring a real failure — for example by repeatedly
+// triggering PartialSuccessError or by spamming public key offer queries —
+// neither of which increment the MaxAuthTries failure counter.
+const maxAuthServerAttempts = 128
+
 func (s *connection) serverAuthenticate(config *ServerConfig) (*Permissions, error) {
 	if config.PreAuthConnCallback != nil {
 		config.PreAuthConnCallback(s)
@@ -537,6 +632,7 @@ func (s *connection) serverAuthenticate(config *ServerConfig) (*Permissions, err
 	var perms *Permissions

 	authFailures := 0
+	authAttempts := 0
 	noneAuthCount := 0
 	var authErrs []error
 	var calledBannerCallback bool
@@ -565,6 +661,19 @@ userAuthLoop:
 			return nil, &ServerAuthError{Errors: authErrs}
 		}

+		if authAttempts >= maxAuthServerAttempts {
+			discMsg := &disconnectMsg{
+				Reason:  2,
+				Message: "too many authentication attempts",
+			}
+			if err := s.transport.writePacket(Marshal(discMsg)); err != nil {
+				return nil, err
+			}
+			authErrs = append(authErrs, discMsg)
+			return nil, &ServerAuthError{Errors: authErrs}
+		}
+		authAttempts++
+
 		var userAuthReq userAuthRequestMsg
 		if packet, err := s.transport.readPacket(); err != nil {
 			if err == io.EOF {
@@ -737,8 +846,15 @@ userAuthLoop:
 				}

 				signedData := buildDataSignedForAuth(sessionID, userAuthReq, algo, pubKeyData)
-
-				if err := pubKey.Verify(signedData, sig); err != nil {
+				// pubKey is reused below for VerifiedPublicKeyCallback and
+				// must remain the key as presented by the client; derive a
+				// separate value for Verify that carries any applicable
+				// no-touch-required opt-out.
+				pubKeyForVerify := pubKey
+				if noTouchAllowed(pubKey, candidate.perms) {
+					pubKeyForVerify = skKeyWithoutUP(pubKey)
+				}
+				if err := pubKeyForVerify.Verify(signedData, sig); err != nil {
 					return nil, err
 				}

@@ -750,9 +866,16 @@ userAuthLoop:
 					// considered verified and the callback must not run.
 					perms, authErr = config.VerifiedPublicKeyCallback(s, pubKey, perms, algo)
 				}
+				if authErr == nil && perms != nil && perms.CriticalOptions != nil {
+					if saco := perms.CriticalOptions[sourceAddressCriticalOption]; saco != "" {
+						if err := checkSourceAddress(s.RemoteAddr(), saco); err != nil {
+							authErr = err
+						}
+					}
+				}
 			}
 		case "gssapi-with-mic":
-			if authConfig.GSSAPIWithMICConfig == nil {
+			if !gssapiWithMICConfigured(authConfig.GSSAPIWithMICConfig) {
 				authErr = errors.New("ssh: gssapi-with-mic auth not configured")
 				break
 			}
@@ -824,6 +947,13 @@ userAuthLoop:
 		var failureMsg userAuthFailureMsg

 		if partialSuccess, ok := authErr.(*PartialSuccessError); ok {
+			// Permissions are not preserved between authentication steps. To
+			// avoid confusion about the final state of the connection, we
+			// disallow returning non-nil Permissions combined with
+			// PartialSuccessError.
+			if perms != nil {
+				return nil, errors.New("ssh: permissions must be nil when returning PartialSuccessError")
+			}
 			// After a partial success error we don't allow changing the user
 			// name and execute the NoClientAuthCallback.
 			partialSuccessReturned = true
@@ -878,8 +1008,7 @@ userAuthLoop:
 		if authConfig.KeyboardInteractiveCallback != nil {
 			failureMsg.Methods = append(failureMsg.Methods, "keyboard-interactive")
 		}
-		if authConfig.GSSAPIWithMICConfig != nil && authConfig.GSSAPIWithMICConfig.Server != nil &&
-			authConfig.GSSAPIWithMICConfig.AllowLogin != nil {
+		if gssapiWithMICConfigured(authConfig.GSSAPIWithMICConfig) {
 			failureMsg.Methods = append(failureMsg.Methods, "gssapi-with-mic")
 		}

@@ -423,6 +423,9 @@ func (s *Session) wait(reqs <-chan *Request) error {
 	for msg := range reqs {
 		switch msg.Type {
 		case "exit-status":
+			if len(msg.Payload) < 4 {
+				return errors.New("ssh: malformed exit-status request")
+			}
 			wm.status = int(binary.BigEndian.Uint32(msg.Payload))
 		case "exit-signal":
 			var sigval struct {
@@ -0,0 +1,19 @@
+This package (golang.org/x/net/http2) is the original source of truth
+of the Go HTTP/2 implementation.
+
+As of Go 1.27, the source of truth has moved to the standard library
+package net/http/internal/http2.
+All new feature development should happen in that package.
+Only critical bug fixes and security fixes will be backported to x/net.
+
+The x/net package contains two implementations of the HTTP/2 transport and server:
+
+The original implementation (no longer the source of truth).
+
+A reimplementation of the x/net/http2 APIs in terms of net/http.
+This is called "the wrapping implementation", since it wraps net/http.
+
+The original implementation is used when the Go version is less than 1.27.
+
+The wrapping implementation is used when the Go version is at least 1.27.
+The build tag "http2legacy" may be set to use the original implementation.
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

+//go:build !(go1.27 && !http2legacy)
+
 // Transport code's client connection pooling.

 package http2
@@ -14,18 +16,6 @@ import (
 	"sync"
 )

-// ClientConnPool manages a pool of HTTP/2 client connections.
-type ClientConnPool interface {
-	// GetClientConn returns a specific HTTP/2 connection (usually
-	// a TLS-TCP connection) to an HTTP/2 server. On success, the
-	// returned ClientConn accounts for the upcoming RoundTrip
-	// call, so the caller should not omit it. If the caller needs
-	// to, ClientConn.RoundTrip can be called with a bogus
-	// new(http.Request) to release the stream reservation.
-	GetClientConn(req *http.Request, addr string) (*ClientConn, error)
-	MarkDead(*ClientConn)
-}
-
 // clientConnPoolIdleCloser is the interface implemented by ClientConnPool
 // implementations which can close their idle connections.
 type clientConnPoolIdleCloser interface {
@@ -0,0 +1,57 @@
+// Copyright 2026 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http2
+
+import (
+	"context"
+	"net/http"
+)
+
+func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
+	return cc.roundTrip(req)
+}
+
+// SetDoNotReuse marks cc as not reusable for future HTTP requests.
+func (cc *ClientConn) SetDoNotReuse() {
+	cc.setDoNotReuse()
+}
+
+// CanTakeNewRequest reports whether the connection can take a new request,
+// meaning it has not been closed or received or sent a GOAWAY.
+//
+// If the caller is going to immediately make a new request on this
+// connection, use ReserveNewRequest instead.
+func (cc *ClientConn) CanTakeNewRequest() bool {
+	return cc.canTakeNewRequest()
+}
+
+// ReserveNewRequest is like CanTakeNewRequest but also reserves a
+// concurrent stream in cc. The reservation is decremented on the
+// next call to RoundTrip.
+func (cc *ClientConn) ReserveNewRequest() bool {
+	return cc.reserveNewRequest()
+}
+
+// State returns a snapshot of cc's state.
+func (cc *ClientConn) State() ClientConnState {
+	return cc.state()
+}
+
+// Shutdown gracefully closes the client connection, waiting for running streams to complete.
+func (cc *ClientConn) Shutdown(ctx context.Context) error {
+	return cc.shutdown(ctx)
+}
+
+// Close closes the client connection immediately.
+//
+// In-flight requests are interrupted. For a graceful shutdown, use Shutdown instead.
+func (cc *ClientConn) Close() error {
+	return cc.close()
+}
+
+// Ping sends a PING frame to the server and waits for the ack.
+func (cc *ClientConn) Ping(ctx context.Context) error {
+	return cc.ping(ctx)
+}
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

+//go:build !(go1.27 && !http2legacy)
+
 package http2

 import (
@@ -6,7 +6,6 @@ package hpack

 import (
 	"fmt"
-	"strings"
 )

 // headerFieldTable implements a list of HeaderFields.
@@ -55,16 +54,10 @@ func (t *headerFieldTable) len() int {

 // addEntry adds a new entry.
 func (t *headerFieldTable) addEntry(f HeaderField) {
-	// Prevent f from escaping to the heap.
-	f2 := HeaderField{
-		Name:      strings.Clone(f.Name),
-		Value:     strings.Clone(f.Value),
-		Sensitive: f.Sensitive,
-	}
 	id := uint64(t.len()) + t.evictCount + 1
-	t.byName[f2.Name] = id
-	t.byNameValue[pairNameValue{f2.Name, f2.Value}] = id
-	t.ents = append(t.ents, f2)
+	t.byName[f.Name] = id
+	t.byNameValue[pairNameValue{f.Name, f.Value}] = id
+	t.ents = append(t.ents, f)
 }

 // evictOldest evicts the n oldest entries in the table.
@@ -195,7 +195,7 @@ func (s SettingID) String() string {
 }

 // validWireHeaderFieldName reports whether v is a valid header field
-// name (key). See httpguts.ValidHeaderName for the base rules.
+// name (key). See httpguts.ValidHeaderFieldName for the base rules.
 //
 // Further, http2 says:
 //
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

+//go:build !(go1.27 && !http2legacy)
+
 // TODO: turn off the serve goroutine when idle, so
 // an idle conn only has the readFrames goroutine active. (which could
 // also be optimized probably to pin less memory in crypto/tls). This
@@ -88,98 +90,6 @@ var (
 	testHookOnPanic       func(sc *serverConn, panicVal interface{}) (rePanic bool)
 )

-// Server is an HTTP/2 server.
-type Server struct {
-	// MaxHandlers limits the number of http.Handler ServeHTTP goroutines
-	// which may run at a time over all connections.
-	// Negative or zero no limit.
-	// TODO: implement
-	MaxHandlers int
-
-	// MaxConcurrentStreams optionally specifies the number of
-	// concurrent streams that each client may have open at a
-	// time. This is unrelated to the number of http.Handler goroutines
-	// which may be active globally, which is MaxHandlers.
-	// If zero, MaxConcurrentStreams defaults to at least 100, per
-	// the HTTP/2 spec's recommendations.
-	MaxConcurrentStreams uint32
-
-	// MaxDecoderHeaderTableSize optionally specifies the http2
-	// SETTINGS_HEADER_TABLE_SIZE to send in the initial settings frame. It
-	// informs the remote endpoint of the maximum size of the header compression
-	// table used to decode header blocks, in octets. If zero, the default value
-	// of 4096 is used.
-	MaxDecoderHeaderTableSize uint32
-
-	// MaxEncoderHeaderTableSize optionally specifies an upper limit for the
-	// header compression table used for encoding request headers. Received
-	// SETTINGS_HEADER_TABLE_SIZE settings are capped at this limit. If zero,
-	// the default value of 4096 is used.
-	MaxEncoderHeaderTableSize uint32
-
-	// MaxReadFrameSize optionally specifies the largest frame
-	// this server is willing to read. A valid value is between
-	// 16k and 16M, inclusive. If zero or otherwise invalid, a
-	// default value is used.
-	MaxReadFrameSize uint32
-
-	// PermitProhibitedCipherSuites, if true, permits the use of
-	// cipher suites prohibited by the HTTP/2 spec.
-	PermitProhibitedCipherSuites bool
-
-	// IdleTimeout specifies how long until idle clients should be
-	// closed with a GOAWAY frame. PING frames are not considered
-	// activity for the purposes of IdleTimeout.
-	// If zero or negative, there is no timeout.
-	IdleTimeout time.Duration
-
-	// ReadIdleTimeout is the timeout after which a health check using a ping
-	// frame will be carried out if no frame is received on the connection.
-	// If zero, no health check is performed.
-	ReadIdleTimeout time.Duration
-
-	// PingTimeout is the timeout after which the connection will be closed
-	// if a response to a ping is not received.
-	// If zero, a default of 15 seconds is used.
-	PingTimeout time.Duration
-
-	// WriteByteTimeout is the timeout after which a connection will be
-	// closed if no data can be written to it. The timeout begins when data is
-	// available to write, and is extended whenever any bytes are written.
-	// If zero or negative, there is no timeout.
-	WriteByteTimeout time.Duration
-
-	// MaxUploadBufferPerConnection is the size of the initial flow
-	// control window for each connections. The HTTP/2 spec does not
-	// allow this to be smaller than 65535 or larger than 2^32-1.
-	// If the value is outside this range, a default value will be
-	// used instead.
-	MaxUploadBufferPerConnection int32
-
-	// MaxUploadBufferPerStream is the size of the initial flow control
-	// window for each stream. The HTTP/2 spec does not allow this to
-	// be larger than 2^32-1. If the value is zero or larger than the
-	// maximum, a default value will be used instead.
-	MaxUploadBufferPerStream int32
-
-	// NewWriteScheduler constructs a write scheduler for a connection.
-	// If nil, a default scheduler is chosen.
-	//
-	// Deprecated: User-provided write schedulers are deprecated.
-	NewWriteScheduler func() WriteScheduler
-
-	// CountError, if non-nil, is called on HTTP/2 server errors.
-	// It's intended to increment a metric for monitoring, such
-	// as an expvar or Prometheus metric.
-	// The errType consists of only ASCII word characters.
-	CountError func(errType string)
-
-	// Internal state. This is a pointer (rather than embedded directly)
-	// so that we don't embed a Mutex in this struct, which will make the
-	// struct non-copyable, which might break some callers.
-	state *serverInternalState
-}
-
 type serverInternalState struct {
 	mu          sync.Mutex
 	activeConns map[*serverConn]struct{}
@@ -187,6 +97,9 @@ type serverInternalState struct {
 	// Pool of error channels. This is per-Server rather than global
 	// because channels can't be reused across synctest bubbles.
 	errChanPool sync.Pool
+
+	// Used in tests.
+	testNewConn func(*serverConn)
 }

 func (s *serverInternalState) registerConn(sc *serverConn) {
@@ -239,12 +152,7 @@ func (s *serverInternalState) putErrChan(ch chan error) {
 	s.errChanPool.Put(ch)
 }

-// ConfigureServer adds HTTP/2 support to a net/http Server.
-//
-// The configuration conf may be nil.
-//
-// ConfigureServer must be called before s begins serving.
-func ConfigureServer(s *http.Server, conf *Server) error {
+func configureServer(s *http.Server, conf *Server) error {
 	if s == nil {
 		panic("nil *http.Server")
 	}
@@ -349,83 +257,6 @@ func ConfigureServer(s *http.Server, conf *Server) error {
 	return nil
 }

-// ServeConnOpts are options for the Server.ServeConn method.
-type ServeConnOpts struct {
-	// Context is the base context to use.
-	// If nil, context.Background is used.
-	Context context.Context
-
-	// BaseConfig optionally sets the base configuration
-	// for values. If nil, defaults are used.
-	BaseConfig *http.Server
-
-	// Handler specifies which handler to use for processing
-	// requests. If nil, BaseConfig.Handler is used. If BaseConfig
-	// or BaseConfig.Handler is nil, http.DefaultServeMux is used.
-	Handler http.Handler
-
-	// UpgradeRequest is an initial request received on a connection
-	// undergoing an h2c upgrade. The request body must have been
-	// completely read from the connection before calling ServeConn,
-	// and the 101 Switching Protocols response written.
-	UpgradeRequest *http.Request
-
-	// Settings is the decoded contents of the HTTP2-Settings header
-	// in an h2c upgrade request.
-	Settings []byte
-
-	// SawClientPreface is set if the HTTP/2 connection preface
-	// has already been read from the connection.
-	SawClientPreface bool
-}
-
-func (o *ServeConnOpts) context() context.Context {
-	if o != nil && o.Context != nil {
-		return o.Context
-	}
-	return context.Background()
-}
-
-func (o *ServeConnOpts) baseConfig() *http.Server {
-	if o != nil && o.BaseConfig != nil {
-		return o.BaseConfig
-	}
-	return new(http.Server)
-}
-
-func (o *ServeConnOpts) handler() http.Handler {
-	if o != nil {
-		if o.Handler != nil {
-			return o.Handler
-		}
-		if o.BaseConfig != nil && o.BaseConfig.Handler != nil {
-			return o.BaseConfig.Handler
-		}
-	}
-	return http.DefaultServeMux
-}
-
-// ServeConn serves HTTP/2 requests on the provided connection and
-// blocks until the connection is no longer readable.
-//
-// ServeConn starts speaking HTTP/2 assuming that c has not had any
-// reads or writes. It writes its initial settings frame and expects
-// to be able to read the preface and settings frame from the
-// client. If c has a ConnectionState method like a *tls.Conn, the
-// ConnectionState is used to verify the TLS ciphersuite and to set
-// the Request.TLS field in Handlers.
-//
-// ServeConn does not support h2c by itself. Any h2c support must be
-// implemented in terms of providing a suitably-behaving net.Conn.
-//
-// The opts parameter is optional. If nil, default values are used.
-func (s *Server) ServeConn(c net.Conn, opts *ServeConnOpts) {
-	if opts == nil {
-		opts = &ServeConnOpts{}
-	}
-	s.serveConn(c, opts, nil)
-}
-
 func (s *Server) serveConn(c net.Conn, opts *ServeConnOpts, newf func(*serverConn)) {
 	baseCtx, cancel := serverConnBaseContext(c, opts)
 	defer cancel()
@@ -461,6 +292,9 @@ func (s *Server) serveConn(c net.Conn, opts *ServeConnOpts, newf func(*serverCon
 	if newf != nil {
 		newf(sc)
 	}
+	if s.state != nil && s.state.testNewConn != nil {
+		s.state.testNewConn(sc)
+	}

 	s.state.registerConn(sc)
 	defer s.state.unregisterConn(sc)
@@ -570,15 +404,6 @@ func (s *Server) serveConn(c net.Conn, opts *ServeConnOpts, newf func(*serverCon
 	sc.serve(conf)
 }

-func serverConnBaseContext(c net.Conn, opts *ServeConnOpts) (ctx context.Context, cancel func()) {
-	ctx, cancel = context.WithCancel(opts.context())
-	ctx = context.WithValue(ctx, http.LocalAddrContextKey, c.LocalAddr())
-	if hs := opts.baseConfig(); hs != nil {
-		ctx = context.WithValue(ctx, http.ServerContextKey, hs)
-	}
-	return
-}
-
 func (sc *serverConn) rejectConn(err ErrCode, debug string) {
 	sc.vlogf("http2: server rejecting conn: %v, %s", err, debug)
 	// ignoring errors. hanging up anyway.
@@ -2832,21 +2657,6 @@ func (rws *responseWriterState) writeChunk(p []byte) (n int, err error) {
 	return len(p), nil
 }

-// TrailerPrefix is a magic prefix for ResponseWriter.Header map keys
-// that, if present, signals that the map entry is actually for
-// the response trailers, and not the response headers. The prefix
-// is stripped after the ServeHTTP call finishes and the values are
-// sent in the trailers.
-//
-// This mechanism is intended only for trailers that are not known
-// prior to the headers being written. If the set of trailers is fixed
-// or known before the header is written, the normal Go trailers mechanism
-// is preferred:
-//
-//	https://golang.org/pkg/net/http/#ResponseWriter
-//	https://golang.org/pkg/net/http/#example_ResponseWriter_trailers
-const TrailerPrefix = "Trailer:"
-
 // promoteUndeclaredTrailers permits http.Handlers to set trailers
 // after the header has already been flushed. Because the Go
 // ResponseWriter interface has no way to set Trailers (only the
@@ -3123,12 +2933,6 @@ func (w *responseWriter) handlerDone() {
 	responseWriterStatePool.Put(rws)
 }

-// Push errors.
-var (
-	ErrRecursivePush    = errors.New("http2: recursive push not allowed")
-	ErrPushLimitReached = errors.New("http2: push would exceed peer's SETTINGS_MAX_CONCURRENT_STREAMS")
-)
-
 var _ http.Pusher = (*responseWriter)(nil)

 func (w *responseWriter) Push(target string, opts *http.PushOptions) error {
@@ -0,0 +1,221 @@
+// Copyright 2026 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http2
+
+import (
+	"context"
+	"errors"
+	"net"
+	"net/http"
+	"time"
+)
+
+// TrailerPrefix is a magic prefix for ResponseWriter.Header map keys
+// that, if present, signals that the map entry is actually for
+// the response trailers, and not the response headers. The prefix
+// is stripped after the ServeHTTP call finishes and the values are
+// sent in the trailers.
+//
+// This mechanism is intended only for trailers that are not known
+// prior to the headers being written. If the set of trailers is fixed
+// or known before the header is written, the normal Go trailers mechanism
+// is preferred:
+//
+//	https://golang.org/pkg/net/http/#ResponseWriter
+//	https://golang.org/pkg/net/http/#example_ResponseWriter_trailers
+const TrailerPrefix = "Trailer:"
+
+// Push errors.
+var (
+	ErrRecursivePush    = errors.New("http2: recursive push not allowed")
+	ErrPushLimitReached = errors.New("http2: push would exceed peer's SETTINGS_MAX_CONCURRENT_STREAMS")
+)
+
+// ConfigureServer adds HTTP/2 support to a net/http Server.
+//
+// The configuration conf may be nil.
+//
+// ConfigureServer must be called before s begins serving.
+func ConfigureServer(s *http.Server, conf *Server) error {
+	return configureServer(s, conf)
+}
+
+// Server is an HTTP/2 server.
+type Server struct {
+	// MaxHandlers limits the number of http.Handler ServeHTTP goroutines
+	// which may run at a time over all connections.
+	// Negative or zero no limit.
+	// TODO: implement
+	MaxHandlers int
+
+	// MaxConcurrentStreams optionally specifies the number of
+	// concurrent streams that each client may have open at a
+	// time. This is unrelated to the number of http.Handler goroutines
+	// which may be active globally, which is MaxHandlers.
+	// If zero, MaxConcurrentStreams defaults to at least 100, per
+	// the HTTP/2 spec's recommendations.
+	MaxConcurrentStreams uint32
+
+	// MaxDecoderHeaderTableSize optionally specifies the http2
+	// SETTINGS_HEADER_TABLE_SIZE to send in the initial settings frame. It
+	// informs the remote endpoint of the maximum size of the header compression
+	// table used to decode header blocks, in octets. If zero, the default value
+	// of 4096 is used.
+	MaxDecoderHeaderTableSize uint32
+
+	// MaxEncoderHeaderTableSize optionally specifies an upper limit for the
+	// header compression table used for encoding request headers. Received
+	// SETTINGS_HEADER_TABLE_SIZE settings are capped at this limit. If zero,
+	// the default value of 4096 is used.
+	MaxEncoderHeaderTableSize uint32
+
+	// MaxReadFrameSize optionally specifies the largest frame
+	// this server is willing to read. A valid value is between
+	// 16k and 16M, inclusive. If zero or otherwise invalid, a
+	// default value is used.
+	MaxReadFrameSize uint32
+
+	// PermitProhibitedCipherSuites, if true, permits the use of
+	// cipher suites prohibited by the HTTP/2 spec.
+	PermitProhibitedCipherSuites bool
+
+	// IdleTimeout specifies how long until idle clients should be
+	// closed with a GOAWAY frame. PING frames are not considered
+	// activity for the purposes of IdleTimeout.
+	// If zero or negative, there is no timeout.
+	IdleTimeout time.Duration
+
+	// ReadIdleTimeout is the timeout after which a health check using a ping
+	// frame will be carried out if no frame is received on the connection.
+	// If zero, no health check is performed.
+	ReadIdleTimeout time.Duration
+
+	// PingTimeout is the timeout after which the connection will be closed
+	// if a response to a ping is not received.
+	// If zero, a default of 15 seconds is used.
+	PingTimeout time.Duration
+
+	// WriteByteTimeout is the timeout after which a connection will be
+	// closed if no data can be written to it. The timeout begins when data is
+	// available to write, and is extended whenever any bytes are written.
+	// If zero or negative, there is no timeout.
+	WriteByteTimeout time.Duration
+
+	// MaxUploadBufferPerConnection is the size of the initial flow
+	// control window for each connections. The HTTP/2 spec does not
+	// allow this to be smaller than 65535 or larger than 2^32-1.
+	// If the value is outside this range, a default value will be
+	// used instead.
+	MaxUploadBufferPerConnection int32
+
+	// MaxUploadBufferPerStream is the size of the initial flow control
+	// window for each stream. The HTTP/2 spec does not allow this to
+	// be larger than 2^32-1. If the value is zero or larger than the
+	// maximum, a default value will be used instead.
+	MaxUploadBufferPerStream int32
+
+	// NewWriteScheduler constructs a write scheduler for a connection.
+	// If nil, a default scheduler is chosen.
+	//
+	// Deprecated: User-provided write schedulers are deprecated.
+	NewWriteScheduler func() WriteScheduler
+
+	// CountError, if non-nil, is called on HTTP/2 server errors.
+	// It's intended to increment a metric for monitoring, such
+	// as an expvar or Prometheus metric.
+	// The errType consists of only ASCII word characters.
+	CountError func(errType string)
+
+	// Internal state. This is a pointer (rather than embedded directly)
+	// so that we don't embed a Mutex in this struct, which will make the
+	// struct non-copyable, which might break some callers.
+	state *serverInternalState
+}
+
+// ServeConnOpts are options for the Server.ServeConn method.
+type ServeConnOpts struct {
+	// Context is the base context to use.
+	// If nil, context.Background is used.
+	Context context.Context
+
+	// BaseConfig optionally sets the base configuration
+	// for values. If nil, defaults are used.
+	BaseConfig *http.Server
+
+	// Handler specifies which handler to use for processing
+	// requests. If nil, BaseConfig.Handler is used. If BaseConfig
+	// or BaseConfig.Handler is nil, http.DefaultServeMux is used.
+	Handler http.Handler
+
+	// UpgradeRequest is an initial request received on a connection
+	// undergoing an h2c upgrade. The request body must have been
+	// completely read from the connection before calling ServeConn,
+	// and the 101 Switching Protocols response written.
+	UpgradeRequest *http.Request
+
+	// Settings is the decoded contents of the HTTP2-Settings header
+	// in an h2c upgrade request.
+	Settings []byte
+
+	// SawClientPreface is set if the HTTP/2 connection preface
+	// has already been read from the connection.
+	SawClientPreface bool
+}
+
+// ServeConn serves HTTP/2 requests on the provided connection and
+// blocks until the connection is no longer readable.
+//
+// ServeConn starts speaking HTTP/2 assuming that c has not had any
+// reads or writes. It writes its initial settings frame and expects
+// to be able to read the preface and settings frame from the
+// client. If c has a ConnectionState method like a *tls.Conn, the
+// ConnectionState is used to verify the TLS ciphersuite and to set
+// the Request.TLS field in Handlers.
+//
+// ServeConn does not support h2c by itself. Any h2c support must be
+// implemented in terms of providing a suitably-behaving net.Conn.
+//
+// The opts parameter is optional. If nil, default values are used.
+func (s *Server) ServeConn(c net.Conn, opts *ServeConnOpts) {
+	if opts == nil {
+		opts = &ServeConnOpts{}
+	}
+	s.serveConn(c, opts, nil)
+}
+
+func (o *ServeConnOpts) context() context.Context {
+	if o != nil && o.Context != nil {
+		return o.Context
+	}
+	return context.Background()
+}
+
+func (o *ServeConnOpts) baseConfig() *http.Server {
+	if o != nil && o.BaseConfig != nil {
+		return o.BaseConfig
+	}
+	return new(http.Server)
+}
+
+func (o *ServeConnOpts) handler() http.Handler {
+	if o != nil {
+		if o.Handler != nil {
+			return o.Handler
+		}
+		if o.BaseConfig != nil && o.BaseConfig.Handler != nil {
+			return o.BaseConfig.Handler
+		}
+	}
+	return http.DefaultServeMux
+}
+
+func serverConnBaseContext(c net.Conn, opts *ServeConnOpts) (ctx context.Context, cancel func()) {
+	ctx, cancel = context.WithCancel(opts.context())
+	ctx = context.WithValue(ctx, http.LocalAddrContextKey, c.LocalAddr())
+	if hs := opts.baseConfig(); hs != nil {
+		ctx = context.WithValue(ctx, http.ServerContextKey, hs)
+	}
+	return
+}
@@ -0,0 +1,217 @@
+// Copyright 2026 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build go1.27 && !http2legacy
+
+// Server wrapping a net/http.Server.
+
+package http2
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"net"
+	"net/http"
+	"slices"
+	"sync"
+	"time"
+)
+
+type serverInternalState struct {
+	s1            *http.Server
+	initOnce      sync.Once
+	serveConnFunc func(context.Context, net.Conn, http.Handler, bool, *http.Request, []byte)
+}
+
+func configureServer(s *http.Server, conf *Server) error {
+	if s == nil {
+		panic("nil *http.Server")
+	}
+	if conf == nil {
+		conf = new(Server)
+	}
+	if conf.state != nil {
+		// This isn't a panic in the pre-wrapping implementation,
+		// but calling ConfigureServer twice with the same http2.Server
+		// overwrites internal state on the server.
+		// Make the error explicit and early here.
+		panic("ConfigureServer may be called only once per Server")
+	}
+	if h1, h2 := s, conf; h2.IdleTimeout == 0 {
+		if h1.IdleTimeout != 0 {
+			h2.IdleTimeout = h1.IdleTimeout
+		} else {
+			h2.IdleTimeout = h1.ReadTimeout
+		}
+	}
+
+	// Register h2 and http/1.1 ALPN protocols on s.TLSConfig, matching
+	// the pre-wrapping implementation in server.go, so that TLS listeners
+	// built from s.TLSConfig still negotiate HTTP/2.
+	if s.TLSConfig == nil {
+		s.TLSConfig = new(tls.Config)
+	}
+	if !slices.Contains(s.TLSConfig.NextProtos, NextProtoTLS) {
+		s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, NextProtoTLS)
+	}
+	if !slices.Contains(s.TLSConfig.NextProtos, "http/1.1") {
+		s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, "http/1.1")
+	}
+
+	conf.state = &serverInternalState{
+		s1: s,
+	}
+	sconfig := &serverConfig{s: conf}
+	if err := s.Serve(sconfig); err != nil || sconfig.serveConnFunc == nil {
+		panic("http2: net/http does not support this version of x/net/http2")
+	}
+	conf.state.serveConnFunc = sconfig.serveConnFunc
+	return nil
+}
+
+type serverConfig struct {
+	s             *Server
+	serveConnFunc func(context.Context, net.Conn, http.Handler, bool, *http.Request, []byte)
+}
+
+func (*serverConfig) Accept() (net.Conn, error) {
+	return nil, errors.New("unexpected call to Accept")
+}
+func (*serverConfig) Close() error {
+	return nil
+}
+func (*serverConfig) Addr() net.Addr {
+	return nil
+}
+
+func (s *serverConfig) ServeConnFunc(f func(context.Context, net.Conn, http.Handler, bool, *http.Request, []byte)) {
+	s.serveConnFunc = f
+}
+
+func (s *serverConfig) HTTP2Config() http.HTTP2Config {
+	return http.HTTP2Config{
+		MaxConcurrentStreams:          int(s.s.MaxConcurrentStreams),
+		MaxDecoderHeaderTableSize:     int(s.s.MaxDecoderHeaderTableSize),
+		MaxEncoderHeaderTableSize:     int(s.s.MaxEncoderHeaderTableSize),
+		MaxReadFrameSize:              int(s.s.MaxReadFrameSize),
+		PermitProhibitedCipherSuites:  s.s.PermitProhibitedCipherSuites,
+		MaxReceiveBufferPerConnection: int(s.s.MaxUploadBufferPerConnection),
+		MaxReceiveBufferPerStream:     int(s.s.MaxUploadBufferPerStream),
+		SendPingTimeout:               s.s.ReadIdleTimeout,
+		PingTimeout:                   s.s.PingTimeout,
+		WriteByteTimeout:              s.s.WriteByteTimeout,
+		CountError:                    s.s.CountError,
+	}
+}
+
+func (s *serverConfig) IdleTimeout() time.Duration {
+	return s.s.IdleTimeout
+}
+
+type serverConn struct{}
+
+func (s *Server) serveConn(c net.Conn, opts *ServeConnOpts, _ func(*serverConn)) {
+	var serveConnFunc func(context.Context, net.Conn, http.Handler, bool, *http.Request, []byte)
+	switch {
+	case opts.BaseConfig != nil:
+		// The user has provided us with an http.Server to take configuration from.
+		//
+		// We can't send our request to opts.BaseConfig, because an http.Server can
+		// only be associated with a single http2.Server and the user might
+		// use this one with several http.Servers.
+		//
+		// We can't send our request to s.state.s1, because it doesn't contain
+		// the right configuration.
+		//
+		// So create a one-off copy of opts.BaseConfig and use it.
+		h1 := &http.Server{
+			TLSConfig:         opts.BaseConfig.TLSConfig,
+			ReadTimeout:       opts.BaseConfig.ReadTimeout,
+			ReadHeaderTimeout: opts.BaseConfig.ReadHeaderTimeout,
+			WriteTimeout:      opts.BaseConfig.WriteTimeout,
+			IdleTimeout:       opts.BaseConfig.IdleTimeout,
+			MaxHeaderBytes:    opts.BaseConfig.MaxHeaderBytes,
+			ConnState:         opts.BaseConfig.ConnState,
+			ErrorLog:          opts.BaseConfig.ErrorLog,
+			BaseContext:       opts.BaseConfig.BaseContext,
+			ConnContext:       opts.BaseConfig.ConnContext,
+			HTTP2:             opts.BaseConfig.HTTP2,
+		}
+		sconfig := &serverConfig{s: s}
+		if err := h1.Serve(sconfig); err != nil || sconfig.serveConnFunc == nil {
+			panic("http2: net/http does not support this version of x/net/http2")
+		}
+		serveConnFunc = sconfig.serveConnFunc
+	case s.state != nil:
+		serveConnFunc = s.state.serveConnFunc
+	default:
+		// Strange-but-true: Server has no concurrency-safe way to initialize
+		// its internal state, so historically ServeConn just doesn't use any
+		// persistent state if you don't call ConfigureServer first.
+		//
+		// If ConfigureServer hasn't been called, create a one-off http.Server
+		// for the connection, since we don't have any way to keep one around for reuse.
+		h1 := &http.Server{}
+		sconfig := &serverConfig{s: s}
+		if err := h1.Serve(sconfig); err != nil || sconfig.serveConnFunc == nil {
+			panic("http2: net/http does not support this version of x/net/http2")
+		}
+		serveConnFunc = sconfig.serveConnFunc
+	}
+
+	ctx, cancel := serverConnBaseContext(c, opts)
+	defer cancel()
+	serveConnFunc(ctx, c, opts.handler(), opts.SawClientPreface, opts.UpgradeRequest, opts.Settings)
+
+}
+
+// FrameWriteRequest is a request to write a frame.
+//
+// Deprecated: User-provided write schedulers are deprecated.
+type FrameWriteRequest struct {
+	// Ideally we'd define this in writesched_common.go,
+	// to avoid duplicating an exported symbol across two files,
+	// but the changes required to make this work are fairly large.
+}
+
+func (wr FrameWriteRequest) StreamID() uint32 {
+	return 0
+}
+
+func (wr FrameWriteRequest) DataSize() int {
+	return 0
+}
+
+func (wr FrameWriteRequest) Consume(n int32) (FrameWriteRequest, FrameWriteRequest, int) {
+	return FrameWriteRequest{}, FrameWriteRequest{}, 0
+}
+
+func (wr FrameWriteRequest) String() string {
+	return ""
+}
+
+// NewPriorityWriteScheduler is deprecated.
+//
+// Deprecated: User-provided write schedulers are deprecated.
+func NewPriorityWriteScheduler(cfg *PriorityWriteSchedulerConfig) WriteScheduler {
+	return unsupportedWriteScheduler{}
+}
+
+// NewRandomWriteScheduler is deprecated.
+//
+// Deprecated: User-provided write schedulers are deprecated.
+func NewRandomWriteScheduler() WriteScheduler {
+	return unsupportedWriteScheduler{}
+}
+
+type unsupportedWriteScheduler struct{}
+
+func (unsupportedWriteScheduler) OpenStream(streamID uint32, options OpenStreamOptions) {}
+func (unsupportedWriteScheduler) CloseStream(streamID uint32)                           {}
+func (unsupportedWriteScheduler) AdjustStream(streamID uint32, priority PriorityParam)  {}
+func (unsupportedWriteScheduler) Push(wr FrameWriteRequest)                             {}
+func (unsupportedWriteScheduler) Pop() (wr FrameWriteRequest, ok bool) {
+	return FrameWriteRequest{}, false
+}
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

+//go:build !(go1.27 && !http2legacy)
+
 // Transport code.

 package http2
@@ -21,20 +23,17 @@ import (
 	"log"
 	"math"
 	"math/bits"
-	mathrand "math/rand"
 	"net"
 	"net/http"
 	"net/http/httptrace"
 	"net/textproto"
 	"strconv"
-	"strings"
 	"sync"
 	"sync/atomic"
 	"time"

 	"golang.org/x/net/http/httpguts"
 	"golang.org/x/net/http2/hpack"
-	"golang.org/x/net/idna"
 	"golang.org/x/net/internal/httpcommon"
 )

@@ -60,123 +59,7 @@ const (
 	defaultMaxConcurrentStreams = 1000
 )

-// Transport is an HTTP/2 Transport.
-//
-// A Transport internally caches connections to servers. It is safe
-// for concurrent use by multiple goroutines.
-type Transport struct {
-	// DialTLSContext specifies an optional dial function with context for
-	// creating TLS connections for requests.
-	//
-	// If DialTLSContext and DialTLS is nil, tls.Dial is used.
-	//
-	// If the returned net.Conn has a ConnectionState method like tls.Conn,
-	// it will be used to set http.Response.TLS.
-	DialTLSContext func(ctx context.Context, network, addr string, cfg *tls.Config) (net.Conn, error)
-
-	// DialTLS specifies an optional dial function for creating
-	// TLS connections for requests.
-	//
-	// If DialTLSContext and DialTLS is nil, tls.Dial is used.
-	//
-	// Deprecated: Use DialTLSContext instead, which allows the transport
-	// to cancel dials as soon as they are no longer needed.
-	// If both are set, DialTLSContext takes priority.
-	DialTLS func(network, addr string, cfg *tls.Config) (net.Conn, error)
-
-	// TLSClientConfig specifies the TLS configuration to use with
-	// tls.Client. If nil, the default configuration is used.
-	TLSClientConfig *tls.Config
-
-	// ConnPool optionally specifies an alternate connection pool to use.
-	// If nil, the default is used.
-	ConnPool ClientConnPool
-
-	// DisableCompression, if true, prevents the Transport from
-	// requesting compression with an "Accept-Encoding: gzip"
-	// request header when the Request contains no existing
-	// Accept-Encoding value. If the Transport requests gzip on
-	// its own and gets a gzipped response, it's transparently
-	// decoded in the Response.Body. However, if the user
-	// explicitly requested gzip it is not automatically
-	// uncompressed.
-	DisableCompression bool
-
-	// AllowHTTP, if true, permits HTTP/2 requests using the insecure,
-	// plain-text "http" scheme. Note that this does not enable h2c support.
-	AllowHTTP bool
-
-	// MaxHeaderListSize is the http2 SETTINGS_MAX_HEADER_LIST_SIZE to
-	// send in the initial settings frame. It is how many bytes
-	// of response headers are allowed. Unlike the http2 spec, zero here
-	// means to use a default limit (currently 10MB). If you actually
-	// want to advertise an unlimited value to the peer, Transport
-	// interprets the highest possible value here (0xffffffff or 1<<32-1)
-	// to mean no limit.
-	MaxHeaderListSize uint32
-
-	// MaxReadFrameSize is the http2 SETTINGS_MAX_FRAME_SIZE to send in the
-	// initial settings frame. It is the size in bytes of the largest frame
-	// payload that the sender is willing to receive. If 0, no setting is
-	// sent, and the value is provided by the peer, which should be 16384
-	// according to the spec:
-	// https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2.
-	// Values are bounded in the range 16k to 16M.
-	MaxReadFrameSize uint32
-
-	// MaxDecoderHeaderTableSize optionally specifies the http2
-	// SETTINGS_HEADER_TABLE_SIZE to send in the initial settings frame. It
-	// informs the remote endpoint of the maximum size of the header compression
-	// table used to decode header blocks, in octets. If zero, the default value
-	// of 4096 is used.
-	MaxDecoderHeaderTableSize uint32
-
-	// MaxEncoderHeaderTableSize optionally specifies an upper limit for the
-	// header compression table used for encoding request headers. Received
-	// SETTINGS_HEADER_TABLE_SIZE settings are capped at this limit. If zero,
-	// the default value of 4096 is used.
-	MaxEncoderHeaderTableSize uint32
-
-	// StrictMaxConcurrentStreams controls whether the server's
-	// SETTINGS_MAX_CONCURRENT_STREAMS should be respected
-	// globally. If false, new TCP connections are created to the
-	// server as needed to keep each under the per-connection
-	// SETTINGS_MAX_CONCURRENT_STREAMS limit. If true, the
-	// server's SETTINGS_MAX_CONCURRENT_STREAMS is interpreted as
-	// a global limit and callers of RoundTrip block when needed,
-	// waiting for their turn.
-	StrictMaxConcurrentStreams bool
-
-	// IdleConnTimeout is the maximum amount of time an idle
-	// (keep-alive) connection will remain idle before closing
-	// itself.
-	// Zero means no limit.
-	IdleConnTimeout time.Duration
-
-	// ReadIdleTimeout is the timeout after which a health check using ping
-	// frame will be carried out if no frame is received on the connection.
-	// Note that a ping response will is considered a received frame, so if
-	// there is no other traffic on the connection, the health check will
-	// be performed every ReadIdleTimeout interval.
-	// If zero, no health check is performed.
-	ReadIdleTimeout time.Duration
-
-	// PingTimeout is the timeout after which the connection will be closed
-	// if a response to Ping is not received.
-	// Defaults to 15s.
-	PingTimeout time.Duration
-
-	// WriteByteTimeout is the timeout after which the connection will be
-	// closed no data can be written to it. The timeout begins when data is
-	// available to write, and is extended whenever any bytes are written.
-	WriteByteTimeout time.Duration
-
-	// CountError, if non-nil, is called on HTTP/2 transport errors.
-	// It's intended to increment a metric for monitoring, such
-	// as an expvar or Prometheus metric.
-	// The errType consists of only ASCII word characters.
-	CountError func(errType string)
-
+type transportInternal struct {
 	// t1, if non-nil, is the standard library Transport using
 	// this transport. Its settings are used (but not its
 	// RoundTrip method, etc).
@@ -217,27 +100,18 @@ func (t *Transport) disableCompression() bool {
 	return t.DisableCompression || (t.t1 != nil && t.t1.DisableCompression)
 }

-// ConfigureTransport configures a net/http HTTP/1 Transport to use HTTP/2.
-// It returns an error if t1 has already been HTTP/2-enabled.
-//
-// Use ConfigureTransports instead to configure the HTTP/2 Transport.
-func ConfigureTransport(t1 *http.Transport) error {
-	_, err := ConfigureTransports(t1)
+func configureTransport(t1 *http.Transport) error {
+	_, err := configureTransports(t1)
 	return err
 }

-// ConfigureTransports configures a net/http HTTP/1 Transport to use HTTP/2.
-// It returns a new HTTP/2 Transport for further configuration.
-// It returns an error if t1 has already been HTTP/2-enabled.
-func ConfigureTransports(t1 *http.Transport) (*Transport, error) {
-	return configureTransports(t1)
-}
-
 func configureTransports(t1 *http.Transport) (*Transport, error) {
 	connPool := new(clientConnPool)
 	t2 := &Transport{
 		ConnPool: noDialClientConnPool{connPool},
-		t1:       t1,
+		transportInternal: transportInternal{
+			t1: t1,
+		},
 	}
 	connPool.t = t2
 	if err := registerHTTPSProtocol(t1, noDialH2RoundTripper{t2}); err != nil {
@@ -525,68 +399,7 @@ func (sew stickyErrWriter) Write(p []byte) (n int, err error) {
 	return n, err
 }

-// noCachedConnError is the concrete type of ErrNoCachedConn, which
-// needs to be detected by net/http regardless of whether it's its
-// bundled version (in h2_bundle.go with a rewritten type name) or
-// from a user's x/net/http2. As such, as it has a unique method name
-// (IsHTTP2NoCachedConnError) that net/http sniffs for via func
-// isNoCachedConnError.
-type noCachedConnError struct{}
-
-func (noCachedConnError) IsHTTP2NoCachedConnError() {}
-func (noCachedConnError) Error() string             { return "http2: no cached connection was available" }
-
-// isNoCachedConnError reports whether err is of type noCachedConnError
-// or its equivalent renamed type in net/http2's h2_bundle.go. Both types
-// may coexist in the same running program.
-func isNoCachedConnError(err error) bool {
-	_, ok := err.(interface{ IsHTTP2NoCachedConnError() })
-	return ok
-}
-
-var ErrNoCachedConn error = noCachedConnError{}
-
-// RoundTripOpt are options for the Transport.RoundTripOpt method.
-type RoundTripOpt struct {
-	// OnlyCachedConn controls whether RoundTripOpt may
-	// create a new TCP connection. If set true and
-	// no cached connection is available, RoundTripOpt
-	// will return ErrNoCachedConn.
-	OnlyCachedConn bool
-
-	allowHTTP bool // allow http:// URLs
-}
-
-func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
-	return t.RoundTripOpt(req, RoundTripOpt{})
-}
-
-// authorityAddr returns a given authority (a host/IP, or host:port / ip:port)
-// and returns a host:port. The port 443 is added if needed.
-func authorityAddr(scheme string, authority string) (addr string) {
-	host, port, err := net.SplitHostPort(authority)
-	if err != nil { // authority didn't have a port
-		host = authority
-		port = ""
-	}
-	if port == "" { // authority's port was empty
-		port = "443"
-		if scheme == "http" {
-			port = "80"
-		}
-	}
-	if a, err := idna.ToASCII(host); err == nil {
-		host = a
-	}
-	// IPv6 address literal, without a port:
-	if strings.HasPrefix(host, "[") && strings.HasSuffix(host, "]") {
-		return host + ":" + port
-	}
-	return net.JoinHostPort(host, port)
-}
-
-// RoundTripOpt is like RoundTrip, but takes options.
-func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Response, error) {
+func (t *Transport) roundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Response, error) {
 	switch req.URL.Scheme {
 	case "https":
 		// Always okay.
@@ -597,126 +410,15 @@ func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Res
 	default:
 		return nil, errors.New("http2: unsupported scheme")
 	}
-
-	addr := authorityAddr(req.URL.Scheme, req.URL.Host)
-	for retry := 0; ; retry++ {
-		cc, err := t.connPool().GetClientConn(req, addr)
-		if err != nil {
-			t.vlogf("http2: Transport failed to get client conn for %s: %v", addr, err)
-			return nil, err
-		}
-		reused := !atomic.CompareAndSwapUint32(&cc.atomicReused, 0, 1)
-		traceGotConn(req, cc, reused)
-		res, err := cc.RoundTrip(req)
-		if err != nil && retry <= 6 {
-			roundTripErr := err
-			if req, err = shouldRetryRequest(req, err); err == nil {
-				// After the first retry, do exponential backoff with 10% jitter.
-				if retry == 0 {
-					t.vlogf("RoundTrip retrying after failure: %v", roundTripErr)
-					continue
-				}
-				backoff := float64(uint(1) << (uint(retry) - 1))
-				backoff += backoff * (0.1 * mathrand.Float64())
-				d := time.Second * time.Duration(backoff)
-				tm := time.NewTimer(d)
-				select {
-				case <-tm.C:
-					t.vlogf("RoundTrip retrying after failure: %v", roundTripErr)
-					continue
-				case <-req.Context().Done():
-					tm.Stop()
-					err = req.Context().Err()
-				}
-			}
-		}
-		if err == errClientConnNotEstablished {
-			// This ClientConn was created recently,
-			// this is the first request to use it,
-			// and the connection is closed and not usable.
-			//
-			// In this state, cc.idleTimer will remove the conn from the pool
-			// when it fires. Stop the timer and remove it here so future requests
-			// won't try to use this connection.
-			//
-			// If the timer has already fired and we're racing it, the redundant
-			// call to MarkDead is harmless.
-			if cc.idleTimer != nil {
-				cc.idleTimer.Stop()
-			}
-			t.connPool().MarkDead(cc)
-		}
-		if err != nil {
-			t.vlogf("RoundTrip failure: %v", err)
-			return nil, err
-		}
-		return res, nil
-	}
+	return t.roundTripViaPool(req, opt, t.connPool())
 }

-// CloseIdleConnections closes any connections which were previously
-// connected from previous requests but are now sitting idle.
-// It does not interrupt any connections currently in use.
-func (t *Transport) CloseIdleConnections() {
+func (t *Transport) closeIdleConnections() {
 	if cp, ok := t.connPool().(clientConnPoolIdleCloser); ok {
 		cp.closeIdleConnections()
 	}
 }

-var (
-	errClientConnClosed         = errors.New("http2: client conn is closed")
-	errClientConnUnusable       = errors.New("http2: client conn not usable")
-	errClientConnNotEstablished = errors.New("http2: client conn could not be established")
-	errClientConnGotGoAway      = errors.New("http2: Transport received Server's graceful shutdown GOAWAY")
-	errClientConnForceClosed    = errors.New("http2: client connection force closed via ClientConn.Close")
-)
-
-// shouldRetryRequest is called by RoundTrip when a request fails to get
-// response headers. It is always called with a non-nil error.
-// It returns either a request to retry (either the same request, or a
-// modified clone), or an error if the request can't be replayed.
-func shouldRetryRequest(req *http.Request, err error) (*http.Request, error) {
-	if !canRetryError(err) {
-		return nil, err
-	}
-	// If the Body is nil (or http.NoBody), it's safe to reuse
-	// this request and its Body.
-	if req.Body == nil || req.Body == http.NoBody {
-		return req, nil
-	}
-
-	// If the request body can be reset back to its original
-	// state via the optional req.GetBody, do that.
-	if req.GetBody != nil {
-		body, err := req.GetBody()
-		if err != nil {
-			return nil, err
-		}
-		newReq := *req
-		newReq.Body = body
-		return &newReq, nil
-	}
-
-	// The Request.Body can't reset back to the beginning, but we
-	// don't seem to have started to read from it yet, so reuse
-	// the request directly.
-	if err == errClientConnUnusable {
-		return req, nil
-	}
-
-	return nil, fmt.Errorf("http2: Transport: cannot retry err [%v] after Request.Body was written; define Request.GetBody to avoid this error", err)
-}
-
-func canRetryError(err error) bool {
-	if err == errClientConnUnusable || err == errClientConnGotGoAway {
-		return true
-	}
-	if se, ok := err.(StreamError); ok {
-		return se.Code == ErrCodeRefusedStream
-	}
-	return false
-}
-
 func (t *Transport) dialClientConn(ctx context.Context, addr string, singleUse bool) (*ClientConn, error) {
 	host, _, err := net.SplitHostPort(addr)
 	if err != nil {
@@ -743,27 +445,6 @@ func (t *Transport) newTLSConfig(host string) *tls.Config {
 	return cfg
 }

-func (t *Transport) dialTLS(ctx context.Context, network, addr string, tlsCfg *tls.Config) (net.Conn, error) {
-	if t.DialTLSContext != nil {
-		return t.DialTLSContext(ctx, network, addr, tlsCfg)
-	} else if t.DialTLS != nil {
-		return t.DialTLS(network, addr, tlsCfg)
-	}
-
-	tlsCn, err := t.dialTLSWithContext(ctx, network, addr, tlsCfg)
-	if err != nil {
-		return nil, err
-	}
-	state := tlsCn.ConnectionState()
-	if p := state.NegotiatedProtocol; p != NextProtoTLS {
-		return nil, fmt.Errorf("http2: unexpected ALPN protocol %q; want %q", p, NextProtoTLS)
-	}
-	if !state.NegotiatedProtocolIsMutual {
-		return nil, errors.New("http2: could not negotiate protocol mutually")
-	}
-	return tlsCn, nil
-}
-
 // disableKeepAlives reports whether connections should be closed as
 // soon as possible after handling the first request.
 func (t *Transport) disableKeepAlives() bool {
@@ -777,7 +458,7 @@ func (t *Transport) expectContinueTimeout() time.Duration {
 	return t.t1.ExpectContinueTimeout
 }

-func (t *Transport) NewClientConn(c net.Conn) (*ClientConn, error) {
+func (t *Transport) newUserClientConn(c net.Conn) (*ClientConn, error) {
 	return t.newClientConn(c, t.disableKeepAlives(), nil)
 }

@@ -890,8 +571,7 @@ func (cc *ClientConn) healthCheck() {
 	}
 }

-// SetDoNotReuse marks cc as not reusable for future HTTP requests.
-func (cc *ClientConn) SetDoNotReuse() {
+func (cc *ClientConn) setDoNotReuse() {
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
 	cc.doNotReuse = true
@@ -932,21 +612,13 @@ func (cc *ClientConn) setGoAway(f *GoAwayFrame) {
 	}
 }

-// CanTakeNewRequest reports whether the connection can take a new request,
-// meaning it has not been closed or received or sent a GOAWAY.
-//
-// If the caller is going to immediately make a new request on this
-// connection, use ReserveNewRequest instead.
-func (cc *ClientConn) CanTakeNewRequest() bool {
+func (cc *ClientConn) canTakeNewRequest() bool {
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
 	return cc.canTakeNewRequestLocked()
 }

-// ReserveNewRequest is like CanTakeNewRequest but also reserves a
-// concurrent stream in cc. The reservation is decremented on the
-// next call to RoundTrip.
-func (cc *ClientConn) ReserveNewRequest() bool {
+func (cc *ClientConn) reserveNewRequest() bool {
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
 	if st := cc.idleStateLocked(); !st.canTakeNewRequest {
@@ -956,41 +628,7 @@ func (cc *ClientConn) ReserveNewRequest() bool {
 	return true
 }

-// ClientConnState describes the state of a ClientConn.
-type ClientConnState struct {
-	// Closed is whether the connection is closed.
-	Closed bool
-
-	// Closing is whether the connection is in the process of
-	// closing. It may be closing due to shutdown, being a
-	// single-use connection, being marked as DoNotReuse, or
-	// having received a GOAWAY frame.
-	Closing bool
-
-	// StreamsActive is how many streams are active.
-	StreamsActive int
-
-	// StreamsReserved is how many streams have been reserved via
-	// ClientConn.ReserveNewRequest.
-	StreamsReserved int
-
-	// StreamsPending is how many requests have been sent in excess
-	// of the peer's advertised MaxConcurrentStreams setting and
-	// are waiting for other streams to complete.
-	StreamsPending int
-
-	// MaxConcurrentStreams is how many concurrent streams the
-	// peer advertised as acceptable. Zero means no SETTINGS
-	// frame has been received yet.
-	MaxConcurrentStreams uint32
-
-	// LastIdle, if non-zero, is when the connection last
-	// transitioned to idle state.
-	LastIdle time.Time
-}
-
-// State returns a snapshot of cc's state.
-func (cc *ClientConn) State() ClientConnState {
+func (cc *ClientConn) state() ClientConnState {
 	cc.wmu.Lock()
 	maxConcurrent := cc.maxConcurrentStreams
 	if !cc.seenSettings {
@@ -1161,6 +799,12 @@ func (cc *ClientConn) closeIfIdle() {
 	cc.closeConn()
 }

+func (cc *ClientConn) stopIdleTimer() {
+	if cc.idleTimer != nil {
+		cc.idleTimer.Stop()
+	}
+}
+
 func (cc *ClientConn) isDoNotReuseAndIdle() bool {
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
@@ -1169,8 +813,7 @@ func (cc *ClientConn) isDoNotReuseAndIdle() bool {

 var shutdownEnterWaitStateHook = func() {}

-// Shutdown gracefully closes the client connection, waiting for running streams to complete.
-func (cc *ClientConn) Shutdown(ctx context.Context) error {
+func (cc *ClientConn) shutdown(ctx context.Context) error {
 	if err := cc.sendGoAway(); err != nil {
 		return err
 	}
@@ -1244,10 +887,7 @@ func (cc *ClientConn) closeForError(err error) {
 	cc.closeConn()
 }

-// Close closes the client connection immediately.
-//
-// In-flight requests are interrupted. For a graceful shutdown, use Shutdown instead.
-func (cc *ClientConn) Close() error {
+func (cc *ClientConn) close() error {
 	cc.closeForError(errClientConnForceClosed)
 	return nil
 }
@@ -1301,11 +941,11 @@ func (cc *ClientConn) decrStreamReservationsLocked() {
 	}
 }

-func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
-	return cc.roundTrip(req, nil)
+func (cc *ClientConn) roundTrip(req *http.Request) (*http.Response, error) {
+	return cc.internalRoundTrip(req, nil)
 }

-func (cc *ClientConn) roundTrip(req *http.Request, streamf func(*clientStream)) (*http.Response, error) {
+func (cc *ClientConn) internalRoundTrip(req *http.Request, streamf func(*clientStream)) (*http.Response, error) {
 	ctx := req.Context()
 	cs := &clientStream{
 		cc:                   cc,
@@ -2125,19 +1765,6 @@ func (cc *ClientConn) readLoop() {
 	}
 }

-// GoAwayError is returned by the Transport when the server closes the
-// TCP connection after sending a GOAWAY frame.
-type GoAwayError struct {
-	LastStreamID uint32
-	ErrCode      ErrCode
-	DebugData    string
-}
-
-func (e GoAwayError) Error() string {
-	return fmt.Sprintf("http2: server sent GOAWAY and closed the connection; LastStreamID=%v, ErrCode=%v, debug=%q",
-		e.LastStreamID, e.ErrCode, e.DebugData)
-}
-
 func isEOFOrNetReadError(err error) bool {
 	if err == io.EOF {
 		return true
@@ -2978,7 +2605,7 @@ func (rl *clientConnReadLoop) processResetStream(f *RSTStreamFrame) error {
 }

 // Ping sends a PING frame to the server and waits for the ack.
-func (cc *ClientConn) Ping(ctx context.Context) error {
+func (cc *ClientConn) ping(ctx context.Context) error {
 	c := make(chan struct{})
 	// Generate a random payload
 	var p [8]byte
@@ -3092,16 +2719,6 @@ func (cc *ClientConn) vlogf(format string, args ...interface{}) {
 	cc.t.vlogf(format, args...)
 }

-func (t *Transport) vlogf(format string, args ...interface{}) {
-	if VerboseLogs {
-		t.logf(format, args...)
-	}
-}
-
-func (t *Transport) logf(format string, args ...interface{}) {
-	log.Printf(format, args...)
-}
-
 var noBody io.ReadCloser = noBodyReader{}

 type noBodyReader struct{}
@@ -3417,17 +3034,3 @@ func traceGot1xxResponseFunc(trace *httptrace.ClientTrace) func(int, textproto.M
 	}
 	return nil
 }
-
-// dialTLSWithContext uses tls.Dialer, added in Go 1.15, to open a TLS
-// connection.
-func (t *Transport) dialTLSWithContext(ctx context.Context, network, addr string, cfg *tls.Config) (*tls.Conn, error) {
-	dialer := &tls.Dialer{
-		Config: cfg,
-	}
-	cn, err := dialer.DialContext(ctx, network, addr)
-	if err != nil {
-		return nil, err
-	}
-	tlsCn := cn.(*tls.Conn) // DialContext comment promises this will always succeed
-	return tlsCn, nil
-}
@@ -0,0 +1,447 @@
+// Copyright 2026 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http2
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"log"
+	mathrand "math/rand"
+	"net"
+	"net/http"
+	"strings"
+	"sync/atomic"
+	"time"
+
+	"golang.org/x/net/idna"
+)
+
+// ConfigureTransport configures a net/http HTTP/1 Transport to use HTTP/2.
+// It returns an error if t1 has already been HTTP/2-enabled.
+//
+// Use ConfigureTransports instead to configure the HTTP/2 Transport.
+func ConfigureTransport(t1 *http.Transport) error {
+	return configureTransport(t1)
+}
+
+// ConfigureTransports configures a net/http HTTP/1 Transport to use HTTP/2.
+// It returns a new HTTP/2 Transport for further configuration.
+// It returns an error if t1 has already been HTTP/2-enabled.
+func ConfigureTransports(t1 *http.Transport) (*Transport, error) {
+	return configureTransports(t1)
+}
+
+// Transport is an HTTP/2 Transport.
+//
+// A Transport internally caches connections to servers. It is safe
+// for concurrent use by multiple goroutines.
+type Transport struct {
+	// DialTLSContext specifies an optional dial function with context for
+	// creating TLS connections for requests.
+	//
+	// If DialTLSContext and DialTLS is nil, tls.Dial is used.
+	//
+	// If the returned net.Conn has a ConnectionState method like tls.Conn,
+	// it will be used to set http.Response.TLS.
+	DialTLSContext func(ctx context.Context, network, addr string, cfg *tls.Config) (net.Conn, error)
+
+	// DialTLS specifies an optional dial function for creating
+	// TLS connections for requests.
+	//
+	// If DialTLSContext and DialTLS is nil, tls.Dial is used.
+	//
+	// Deprecated: Use DialTLSContext instead, which allows the transport
+	// to cancel dials as soon as they are no longer needed.
+	// If both are set, DialTLSContext takes priority.
+	DialTLS func(network, addr string, cfg *tls.Config) (net.Conn, error)
+
+	// TLSClientConfig specifies the TLS configuration to use with
+	// tls.Client. If nil, the default configuration is used.
+	TLSClientConfig *tls.Config
+
+	// ConnPool optionally specifies an alternate connection pool to use.
+	// If nil, the default is used.
+	ConnPool ClientConnPool
+
+	// DisableCompression, if true, prevents the Transport from
+	// requesting compression with an "Accept-Encoding: gzip"
+	// request header when the Request contains no existing
+	// Accept-Encoding value. If the Transport requests gzip on
+	// its own and gets a gzipped response, it's transparently
+	// decoded in the Response.Body. However, if the user
+	// explicitly requested gzip it is not automatically
+	// uncompressed.
+	DisableCompression bool
+
+	// AllowHTTP, if true, permits HTTP/2 requests using the insecure,
+	// plain-text "http" scheme. Note that this does not enable h2c support.
+	AllowHTTP bool
+
+	// MaxHeaderListSize is the http2 SETTINGS_MAX_HEADER_LIST_SIZE to
+	// send in the initial settings frame. It is how many bytes
+	// of response headers are allowed. Unlike the http2 spec, zero here
+	// means to use a default limit (currently 10MB). If you actually
+	// want to advertise an unlimited value to the peer, Transport
+	// interprets the highest possible value here (0xffffffff or 1<<32-1)
+	// to mean no limit.
+	MaxHeaderListSize uint32
+
+	// MaxReadFrameSize is the http2 SETTINGS_MAX_FRAME_SIZE to send in the
+	// initial settings frame. It is the size in bytes of the largest frame
+	// payload that the sender is willing to receive. If 0, no setting is
+	// sent, and the value is provided by the peer, which should be 16384
+	// according to the spec:
+	// https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2.
+	// Values are bounded in the range 16k to 16M.
+	MaxReadFrameSize uint32
+
+	// MaxDecoderHeaderTableSize optionally specifies the http2
+	// SETTINGS_HEADER_TABLE_SIZE to send in the initial settings frame. It
+	// informs the remote endpoint of the maximum size of the header compression
+	// table used to decode header blocks, in octets. If zero, the default value
+	// of 4096 is used.
+	MaxDecoderHeaderTableSize uint32
+
+	// MaxEncoderHeaderTableSize optionally specifies an upper limit for the
+	// header compression table used for encoding request headers. Received
+	// SETTINGS_HEADER_TABLE_SIZE settings are capped at this limit. If zero,
+	// the default value of 4096 is used.
+	MaxEncoderHeaderTableSize uint32
+
+	// StrictMaxConcurrentStreams controls whether the server's
+	// SETTINGS_MAX_CONCURRENT_STREAMS should be respected
+	// globally. If false, new TCP connections are created to the
+	// server as needed to keep each under the per-connection
+	// SETTINGS_MAX_CONCURRENT_STREAMS limit. If true, the
+	// server's SETTINGS_MAX_CONCURRENT_STREAMS is interpreted as
+	// a global limit and callers of RoundTrip block when needed,
+	// waiting for their turn.
+	StrictMaxConcurrentStreams bool
+
+	// IdleConnTimeout is the maximum amount of time an idle
+	// (keep-alive) connection will remain idle before closing
+	// itself.
+	// Zero means no limit.
+	IdleConnTimeout time.Duration
+
+	// ReadIdleTimeout is the timeout after which a health check using ping
+	// frame will be carried out if no frame is received on the connection.
+	// Note that a ping response will is considered a received frame, so if
+	// there is no other traffic on the connection, the health check will
+	// be performed every ReadIdleTimeout interval.
+	// If zero, no health check is performed.
+	ReadIdleTimeout time.Duration
+
+	// PingTimeout is the timeout after which the connection will be closed
+	// if a response to Ping is not received.
+	// Defaults to 15s.
+	PingTimeout time.Duration
+
+	// WriteByteTimeout is the timeout after which the connection will be
+	// closed no data can be written to it. The timeout begins when data is
+	// available to write, and is extended whenever any bytes are written.
+	WriteByteTimeout time.Duration
+
+	// CountError, if non-nil, is called on HTTP/2 transport errors.
+	// It's intended to increment a metric for monitoring, such
+	// as an expvar or Prometheus metric.
+	// The errType consists of only ASCII word characters.
+	CountError func(errType string)
+
+	// Internal state, differs between wrapped and non-wrapped implementations.
+	transportInternal
+}
+
+var (
+	errClientConnClosed         = errors.New("http2: client conn is closed")
+	errClientConnNotEstablished = errors.New("http2: client conn could not be established")
+	errClientConnGotGoAway      = errors.New("http2: Transport received Server's graceful shutdown GOAWAY")
+	errClientConnForceClosed    = errors.New("http2: client connection force closed via ClientConn.Close")
+	errClientConnUnusable       = errors.New("http2: client conn not usable")
+)
+
+// ClientConnPool manages a pool of HTTP/2 client connections.
+type ClientConnPool interface {
+	// GetClientConn returns a specific HTTP/2 connection (usually
+	// a TLS-TCP connection) to an HTTP/2 server. On success, the
+	// returned ClientConn accounts for the upcoming RoundTrip
+	// call, so the caller should not omit it. If the caller needs
+	// to, ClientConn.RoundTrip can be called with a bogus
+	// new(http.Request) to release the stream reservation.
+	GetClientConn(req *http.Request, addr string) (*ClientConn, error)
+	MarkDead(*ClientConn)
+}
+
+// ClientConnState describes the state of a ClientConn.
+type ClientConnState struct {
+	// Closed is whether the connection is closed.
+	Closed bool
+
+	// Closing is whether the connection is in the process of
+	// closing. It may be closing due to shutdown, being a
+	// single-use connection, being marked as DoNotReuse, or
+	// having received a GOAWAY frame.
+	Closing bool
+
+	// StreamsActive is how many streams are active.
+	StreamsActive int
+
+	// StreamsReserved is how many streams have been reserved via
+	// ClientConn.ReserveNewRequest.
+	StreamsReserved int
+
+	// StreamsPending is how many requests have been sent in excess
+	// of the peer's advertised MaxConcurrentStreams setting and
+	// are waiting for other streams to complete.
+	StreamsPending int
+
+	// MaxConcurrentStreams is how many concurrent streams the
+	// peer advertised as acceptable. Zero means no SETTINGS
+	// frame has been received yet.
+	MaxConcurrentStreams uint32
+
+	// LastIdle, if non-zero, is when the connection last
+	// transitioned to idle state.
+	LastIdle time.Time
+}
+
+// RoundTripOpt are options for the Transport.RoundTripOpt method.
+type RoundTripOpt struct {
+	// OnlyCachedConn controls whether RoundTripOpt may
+	// create a new TCP connection. If set true and
+	// no cached connection is available, RoundTripOpt
+	// will return ErrNoCachedConn.
+
+	// OnlyCachedConn was broken in https://go.dev/cl/16699.
+	OnlyCachedConn bool
+
+	allowHTTP bool // allow http:// URLs
+}
+
+func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
+	return t.RoundTripOpt(req, RoundTripOpt{})
+}
+
+// RoundTripOpt is like RoundTrip, but takes options.
+func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Response, error) {
+	return t.roundTripOpt(req, opt)
+}
+
+// CloseIdleConnections closes any connections which were previously
+// connected from previous requests but are now sitting idle.
+// It does not interrupt any connections currently in use.
+func (t *Transport) CloseIdleConnections() {
+	t.closeIdleConnections()
+}
+
+func (t *Transport) NewClientConn(c net.Conn) (*ClientConn, error) {
+	return t.newUserClientConn(c)
+}
+
+// authorityAddr returns a given authority (a host/IP, or host:port / ip:port)
+// and returns a host:port. The port 443 is added if needed.
+func authorityAddr(scheme string, authority string) (addr string) {
+	host, port, err := net.SplitHostPort(authority)
+	if err != nil { // authority didn't have a port
+		host = authority
+		port = ""
+	}
+	if port == "" { // authority's port was empty
+		port = "443"
+		if scheme == "http" {
+			port = "80"
+		}
+	}
+	if a, err := idna.ToASCII(host); err == nil {
+		host = a
+	}
+	// IPv6 address literal, without a port:
+	if strings.HasPrefix(host, "[") && strings.HasSuffix(host, "]") {
+		return host + ":" + port
+	}
+	return net.JoinHostPort(host, port)
+}
+
+func (t *Transport) roundTripViaPool(req *http.Request, opt RoundTripOpt, pool ClientConnPool) (*http.Response, error) {
+	addr := authorityAddr(req.URL.Scheme, req.URL.Host)
+	for retry := 0; ; retry++ {
+		cc, err := pool.GetClientConn(req, addr)
+		if err != nil {
+			t.vlogf("http2: Transport failed to get client conn for %s: %v", addr, err)
+			return nil, err
+		}
+		reused := !atomic.CompareAndSwapUint32(&cc.atomicReused, 0, 1)
+		traceGotConn(req, cc, reused)
+		res, err := cc.RoundTrip(req)
+		if err != nil && retry <= 6 {
+			roundTripErr := err
+			if req, err = shouldRetryRequest(req, err); err == nil {
+				// After the first retry, do exponential backoff with 10% jitter.
+				if retry == 0 {
+					t.vlogf("RoundTrip retrying after failure: %v", roundTripErr)
+					continue
+				}
+				backoff := float64(uint(1) << (uint(retry) - 1))
+				backoff += backoff * (0.1 * mathrand.Float64())
+				d := time.Second * time.Duration(backoff)
+				tm := time.NewTimer(d)
+				select {
+				case <-tm.C:
+					t.vlogf("RoundTrip retrying after failure: %v", roundTripErr)
+					continue
+				case <-req.Context().Done():
+					tm.Stop()
+					err = req.Context().Err()
+				}
+			}
+		}
+		if err == errClientConnNotEstablished {
+			// This ClientConn was created recently,
+			// this is the first request to use it,
+			// and the connection is closed and not usable.
+			//
+			// In this state, cc.idleTimer will remove the conn from the pool
+			// when it fires. Stop the timer and remove it here so future requests
+			// won't try to use this connection.
+			//
+			// If the timer has already fired and we're racing it, the redundant
+			// call to MarkDead is harmless.
+			cc.stopIdleTimer()
+			pool.MarkDead(cc)
+		}
+		if err != nil {
+			t.vlogf("RoundTrip failure: %v", err)
+			return nil, err
+		}
+		return res, nil
+	}
+}
+
+// shouldRetryRequest is called by RoundTrip when a request fails to get
+// response headers. It is always called with a non-nil error.
+// It returns either a request to retry (either the same request, or a
+// modified clone), or an error if the request can't be replayed.
+func shouldRetryRequest(req *http.Request, err error) (*http.Request, error) {
+	if !canRetryError(err) {
+		return nil, err
+	}
+	// If the Body is nil (or http.NoBody), it's safe to reuse
+	// this request and its Body.
+	if req.Body == nil || req.Body == http.NoBody {
+		return req, nil
+	}
+
+	// If the request body can be reset back to its original
+	// state via the optional req.GetBody, do that.
+	if req.GetBody != nil {
+		body, err := req.GetBody()
+		if err != nil {
+			return nil, err
+		}
+		newReq := *req
+		newReq.Body = body
+		return &newReq, nil
+	}
+
+	// The Request.Body can't reset back to the beginning, but we
+	// don't seem to have started to read from it yet, so reuse
+	// the request directly.
+	if err == errClientConnUnusable {
+		return req, nil
+	}
+
+	return nil, fmt.Errorf("http2: Transport: cannot retry err [%v] after Request.Body was written; define Request.GetBody to avoid this error", err)
+}
+
+func canRetryError(err error) bool {
+	if err == errClientConnUnusable || err == errClientConnGotGoAway {
+		return true
+	}
+	if se, ok := err.(StreamError); ok {
+		return se.Code == ErrCodeRefusedStream
+	}
+	return false
+}
+
+func (t *Transport) vlogf(format string, args ...interface{}) {
+	if VerboseLogs {
+		t.logf(format, args...)
+	}
+}
+
+func (t *Transport) logf(format string, args ...interface{}) {
+	log.Printf(format, args...)
+}
+
+func (t *Transport) dialTLS(ctx context.Context, network, addr string, tlsCfg *tls.Config) (net.Conn, error) {
+	if t.DialTLSContext != nil {
+		return t.DialTLSContext(ctx, network, addr, tlsCfg)
+	} else if t.DialTLS != nil {
+		return t.DialTLS(network, addr, tlsCfg)
+	}
+
+	tlsCn, err := t.dialTLSWithContext(ctx, network, addr, tlsCfg)
+	if err != nil {
+		return nil, err
+	}
+	state := tlsCn.ConnectionState()
+	if p := state.NegotiatedProtocol; p != NextProtoTLS {
+		return nil, fmt.Errorf("http2: unexpected ALPN protocol %q; want %q", p, NextProtoTLS)
+	}
+	if !state.NegotiatedProtocolIsMutual {
+		return nil, errors.New("http2: could not negotiate protocol mutually")
+	}
+	return tlsCn, nil
+}
+
+// dialTLSWithContext uses tls.Dialer, added in Go 1.15, to open a TLS
+// connection.
+func (t *Transport) dialTLSWithContext(ctx context.Context, network, addr string, cfg *tls.Config) (*tls.Conn, error) {
+	dialer := &tls.Dialer{
+		Config: cfg,
+	}
+	cn, err := dialer.DialContext(ctx, network, addr)
+	if err != nil {
+		return nil, err
+	}
+	tlsCn := cn.(*tls.Conn) // DialContext comment promises this will always succeed
+	return tlsCn, nil
+}
+
+// GoAwayError is returned by the Transport when the server closes the
+// TCP connection after sending a GOAWAY frame.
+type GoAwayError struct {
+	LastStreamID uint32
+	ErrCode      ErrCode
+	DebugData    string
+}
+
+func (e GoAwayError) Error() string {
+	return fmt.Sprintf("http2: server sent GOAWAY and closed the connection; LastStreamID=%v, ErrCode=%v, debug=%q",
+		e.LastStreamID, e.ErrCode, e.DebugData)
+}
+
+// noCachedConnError is the concrete type of ErrNoCachedConn, which
+// needs to be detected by net/http regardless of whether it's its
+// bundled version (in h2_bundle.go with a rewritten type name) or
+// from a user's x/net/http2. As such, as it has a unique method name
+// (IsHTTP2NoCachedConnError) that net/http sniffs for via func
+// isNoCachedConnError.
+type noCachedConnError struct{}
+
+func (noCachedConnError) IsHTTP2NoCachedConnError() {}
+func (noCachedConnError) Error() string             { return "http2: no cached connection was available" }
+
+// isNoCachedConnError reports whether err is of type noCachedConnError
+// or its equivalent renamed type in net/http2's h2_bundle.go. Both types
+// may coexist in the same running program.
+func isNoCachedConnError(err error) bool {
+	_, ok := err.(interface{ IsHTTP2NoCachedConnError() })
+	return ok
+}
+
+var ErrNoCachedConn error = noCachedConnError{}
@@ -0,0 +1,392 @@
+// Copyright 2026 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build go1.27 && !http2legacy
+
+// Transport wrapping a net/http.Transport.
+
+package http2
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"math"
+	"net"
+	"net/http"
+	"net/http/httptrace"
+	"slices"
+	"sync"
+	"time"
+)
+
+func configureTransport(t1 *http.Transport) error {
+	_, err := configureTransports(t1)
+	return err
+}
+
+func configureTransports(t1 *http.Transport) (*Transport, error) {
+	// ConfigureTransport returns an http2.Transport with a configuration
+	// linked to the http.Transport's.
+	tr2 := &Transport{}
+	tr2.configure(t1)
+	// Enable HTTP/2 on the transport, as the pre-wrapping implementation did:
+	// net/http does not auto-enable it for a transport with a custom
+	// TLSClientConfig or dialer.
+	if t1.TLSClientConfig == nil {
+		t1.TLSClientConfig = &tls.Config{}
+	}
+	if t1.Protocols == nil {
+		t1.Protocols = new(http.Protocols)
+		t1.Protocols.SetHTTP1(true)
+	}
+	t1.Protocols.SetHTTP2(true)
+	return tr2, nil
+}
+
+// transportConfig is passed to net/http.Transport.RegisterProtocol("http/2", config).
+// It provides the net/http.Transport with access to the configuration in the
+// x/net/http2.Transport.
+type transportConfig struct {
+	t *Transport
+}
+
+// Registered is called by net/http.Transport.RegisterProtocol,
+// to let us know that it understands the registration mechanism we're using.
+func (t transportConfig) Registered(t1 *http.Transport) {
+	t.t.t1 = t1
+}
+
+func (t transportConfig) DisableCompression() bool {
+	return t.t.DisableCompression
+}
+
+func (t transportConfig) MaxHeaderListSize() int64 {
+	return int64(t.t.MaxHeaderListSize)
+}
+
+func (t transportConfig) IdleConnTimeout() time.Duration {
+	return t.t.IdleConnTimeout
+}
+
+func (t transportConfig) HTTP2Config() http.HTTP2Config {
+	return http.HTTP2Config{
+		StrictMaxConcurrentRequests: t.t.StrictMaxConcurrentStreams,
+		MaxDecoderHeaderTableSize:   int(t.t.MaxDecoderHeaderTableSize),
+		MaxEncoderHeaderTableSize:   int(t.t.MaxEncoderHeaderTableSize),
+		MaxReadFrameSize:            int(t.t.MaxReadFrameSize),
+		SendPingTimeout:             t.t.ReadIdleTimeout,
+		PingTimeout:                 t.t.PingTimeout,
+		WriteByteTimeout:            t.t.WriteByteTimeout,
+		CountError:                  t.t.CountError,
+	}
+}
+
+// ExternalRoundTrip reports whether the Transport wants to take control of the RoundTrip call.
+// If the user hasn't configured a custom connection pool, we leave the RoundTrip up to net/http.
+func (t transportConfig) ExternalRoundTrip() bool {
+	return t.t.ConnPool != nil
+}
+
+// RoundTrip is used when the http.Transport is passing control of the full
+// RoundTrip to us--connection pooling, retries, etc.
+//
+// This is only used when the http2.Transport has a user-provided ConnPool.
+// Any other time, net/http handles everything.
+func (t transportConfig) RoundTrip(req *http.Request) (*http.Response, error) {
+	if t.t.ConnPool == nil {
+		return nil, http.ErrSkipAltProtocol
+	}
+	return t.t.RoundTrip(req)
+}
+
+// netConnContextKey passes a net.Conn to http.Transport.NewClientConn.
+// See http2.Transport.NewClientConn.
+type netConnContextKey struct{}
+
+// ConnFromContext lets the http.Transport fetch a net.Conn out of a context
+// passed to NewClientConn. See http2.Transport.NewClientConn.
+func (t transportConfig) ConnFromContext(ctx context.Context) net.Conn {
+	nc, _ := ctx.Value(netConnContextKey{}).(net.Conn)
+	return nc
+}
+
+// http2TransportContextKey marks a RoundTrip as needing its dial handled by the http2.Transport.
+// We set this for http2.RoundTrip calls, where the historical behavior is to use the
+// http2.Transport's dialer.
+type http2TransportContextKey struct{}
+
+// DialFromContext dials a new connection using the http2.Transport's DialTLS/DialTLSContext.
+func (t transportConfig) DialFromContext(ctx context.Context, network, address string) (net.Conn, error) {
+	if ctx.Value(http2TransportContextKey{}) == nil {
+		// We're being called from a RoundTrip that did not start with an http2.Transport.
+		// Use the http.Transport's dialer.
+		return nil, errors.ErrUnsupported
+	}
+
+	tlsConf := t.t.TLSClientConfig
+	if tlsConf == nil {
+		tlsConf = &tls.Config{}
+	} else {
+		tlsConf = tlsConf.Clone()
+	}
+	if !slices.Contains(tlsConf.NextProtos, "h2") {
+		tlsConf.NextProtos = append([]string{"h2"}, tlsConf.NextProtos...)
+	}
+	if tlsConf.ServerName == "" {
+		host, _, err := net.SplitHostPort(address)
+		if err == nil {
+			tlsConf.ServerName = host
+		}
+	}
+	return t.t.dialTLS(ctx, network, address, tlsConf)
+}
+
+type transportInternal struct {
+	initOnce sync.Once
+	t1       *http.Transport
+}
+
+func (t *Transport) init() {
+	t.initOnce.Do(func() {
+		if t.t1 != nil {
+			return
+		}
+		t1 := &http.Transport{}
+		t.configure(t1)
+	})
+}
+
+func (t *Transport) configure(t1 *http.Transport) {
+	t1.RegisterProtocol("http/2", transportConfig{t})
+	// tr2.t1 is set by transportConfig.Registered.
+	if t.t1 != t1 {
+		panic("http2: net/http does not support this version of x/net/http2")
+	}
+}
+
+func (t *Transport) roundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Response, error) {
+	t.init()
+
+	if req.URL.Scheme == "http" && !t.AllowHTTP {
+		return nil, errors.New("http2: unencrypted HTTP/2 not enabled")
+	}
+
+	// When the Transport has a user-provided connection pool (unusual, deprecated),
+	// we need to handle picking a connection, retrys, etc.
+	if t.ConnPool != nil {
+		return t.roundTripViaPool(req, opt, t.ConnPool)
+	}
+
+	// Setting this context key lets net/http know that if it is necessary to dial
+	// a new connection, we should handle the net.Dial.
+	//
+	// Both http.Transport and http2.Transport allow the user to provide a custom
+	// dial function, and historically you only get the dial function from the
+	// Transport you're calling RoundTrip on.
+	ctx := context.WithValue(req.Context(), http2TransportContextKey{}, t)
+	req = req.WithContext(ctx)
+
+	return t.t1.RoundTrip(req)
+}
+
+func (t *Transport) closeIdleConnections() {
+	t.init()
+	t.t1.CloseIdleConnections()
+}
+
+func (t *Transport) newUserClientConn(c net.Conn) (*ClientConn, error) {
+	// http.Transport's NewClientConn doesn't provide a supported way to create
+	// a connection from a net.Conn. (This might be useful to add in the future?)
+	// We're going to craftily sneak one in via the context key, with the
+	// scheme of "http/2" telling NewClientConn to look for it.
+	ctx := context.WithValue(context.Background(), netConnContextKey{}, c)
+
+	nhcc, err := t.t1.NewClientConn(ctx, "http/2", "")
+	if err != nil {
+		return nil, err
+	}
+	cc := &ClientConn{cc: nhcc, tr: t, tconn: c}
+	nhcc.SetStateHook(cc.stateHook)
+	return cc, nil
+}
+
+// ClientConn is the state of a single HTTP/2 client connection to an
+// HTTP/2 server.
+type ClientConn struct {
+	cc         *http.ClientConn
+	tconn      net.Conn
+	tr         *Transport
+	doNotReuse bool
+
+	mu            sync.Mutex
+	closing       bool
+	closed        bool
+	roundTrips    int
+	reserved      int
+	starting      int
+	pending       int
+	maxConcurrent int
+	lastIdle      time.Time
+	shutdownc     chan struct{}
+
+	atomicReused uint32 // whether conn is being reused; atomic
+}
+
+func (cc *ClientConn) roundTrip(req *http.Request) (*http.Response, error) {
+	err := func() error {
+		cc.mu.Lock()
+		defer cc.mu.Unlock()
+		if cc.doNotReuse {
+			return errClientConnUnusable
+		}
+		cc.roundTrips++
+		if cc.reserved > 0 {
+			// We've already reserved a concurrency slot for this request.
+			cc.reserved--
+		} else if cc.cc.Reserve() != nil {
+			// We don't seem to have an available concurrency slot,
+			// so bump the pending count (requests waiting for a slot).
+			cc.pending++
+		}
+		// ClientConn.Shutdown will not shut down the conn while
+		// cc.starting > 0 or cc.cc.InFlight() > 0.
+		//
+		// The starting state covers the gap between us deciding to
+		// start sending the request, and actually sending it.
+		cc.starting++
+		return nil
+	}()
+	if err != nil {
+		return nil, err
+	}
+	resp, err := cc.cc.RoundTrip(req)
+	cc.mu.Lock()
+	cc.starting--
+	if cc.pending > 0 {
+		// A request completing frees up a concurrency slot for
+		// a pending request to start.
+		cc.pending--
+	}
+	cc.updateStateLocked()
+	cc.mu.Unlock()
+	return resp, err
+}
+
+func (cc *ClientConn) canTakeNewRequest() bool {
+	return cc.cc.Available() > 0 && !cc.doNotReuse
+}
+
+func (cc *ClientConn) close() error {
+	return cc.cc.Close()
+}
+
+func (cc *ClientConn) ping(ctx context.Context) error {
+	// Ask net/http to ping its connection by sending a request with a method of ":ping".
+	_, err := cc.cc.RoundTrip((&http.Request{
+		Method: ":ping",
+	}).WithContext(ctx))
+	return err
+}
+
+func (cc *ClientConn) reserveNewRequest() bool {
+	cc.mu.Lock()
+	defer cc.mu.Unlock()
+	if cc.doNotReuse {
+		return false
+	}
+	if err := cc.cc.Reserve(); err != nil {
+		return false
+	}
+	cc.reserved++
+	return true
+}
+
+func (cc *ClientConn) setDoNotReuse() {
+	cc.mu.Lock()
+	defer cc.mu.Unlock()
+	cc.doNotReuse = true
+	cc.closing = true
+}
+
+func (cc *ClientConn) shutdown(ctx context.Context) error {
+	cc.mu.Lock()
+	inFlight := cc.cc.InFlight() + cc.starting
+	if inFlight > 0 && cc.shutdownc == nil {
+		cc.shutdownc = make(chan struct{})
+	}
+	shutdownc := cc.shutdownc
+	cc.mu.Unlock()
+	if shutdownc != nil {
+		// Wait for in-flight requests to finish.
+		select {
+		case <-shutdownc:
+		case <-ctx.Done():
+			return ctx.Err()
+		}
+	}
+	cc.cc.Close()
+	return nil
+}
+
+func (cc *ClientConn) state() ClientConnState {
+	cc.mu.Lock()
+	defer cc.mu.Unlock()
+	cc.updateStateLocked()
+	return ClientConnState{
+		Closed:               cc.closed,
+		Closing:              cc.closing,
+		StreamsActive:        cc.cc.InFlight() - cc.reserved,
+		StreamsReserved:      cc.reserved,
+		StreamsPending:       cc.pending,
+		MaxConcurrentStreams: uint32(min(int64(cc.maxConcurrent), math.MaxUint32)),
+		LastIdle:             cc.lastIdle,
+	}
+}
+
+// stateHook is the http.ClientConn's state hook.
+func (cc *ClientConn) stateHook(*http.ClientConn) {
+	cc.mu.Lock()
+	defer cc.mu.Unlock()
+	cc.updateStateLocked()
+}
+
+func (cc *ClientConn) updateStateLocked() {
+	if cc.cc.Err() != nil && !cc.closed {
+		cc.closing = true
+		cc.closed = true
+		if cc.tr.ConnPool != nil {
+			// Do the ConnPool update in another goroutine,
+			// to avoid holding the conn mutex while it runs.
+			go cc.tr.ConnPool.MarkDead(cc)
+		}
+	}
+	if cc.cc.InFlight() == 0 && cc.roundTrips > 0 && cc.starting == 0 {
+		cc.lastIdle = time.Now()
+	}
+	if !cc.closed {
+		// This is slightly racy (a request could start or finish in between
+		// the Available and InFlight calls), but the best we can do given that
+		// the net/http ClientConn API doesn't expose the conn's max concurrency.
+		cc.maxConcurrent = cc.cc.Available() + cc.cc.InFlight()
+	}
+	if cc.shutdownc != nil && cc.cc.InFlight()+cc.starting == 0 {
+		close(cc.shutdownc)
+		cc.shutdownc = nil
+	}
+}
+
+func (cc *ClientConn) stopIdleTimer() {}
+
+// traceGotConn is (when http2legacy is not enabled) only used for tracing
+// connections acquired while using a user-provided ClientConnPool.
+func traceGotConn(req *http.Request, cc *ClientConn, reused bool) {
+	trace := httptrace.ContextClientTrace(req.Context())
+	if trace == nil || trace.GotConn == nil {
+		return
+	}
+	ci := httptrace.GotConnInfo{Conn: cc.tconn}
+	ci.Reused = reused
+	trace.GotConn(ci)
+}
@@ -2,54 +2,12 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

+//go:build !(go1.27 && !http2legacy)
+
 package http2

 import "fmt"

-// WriteScheduler is the interface implemented by HTTP/2 write schedulers.
-// Methods are never called concurrently.
-//
-// Deprecated: User-provided write schedulers are deprecated.
-type WriteScheduler interface {
-	// OpenStream opens a new stream in the write scheduler.
-	// It is illegal to call this with streamID=0 or with a streamID that is
-	// already open -- the call may panic.
-	OpenStream(streamID uint32, options OpenStreamOptions)
-
-	// CloseStream closes a stream in the write scheduler. Any frames queued on
-	// this stream should be discarded. It is illegal to call this on a stream
-	// that is not open -- the call may panic.
-	CloseStream(streamID uint32)
-
-	// AdjustStream adjusts the priority of the given stream. This may be called
-	// on a stream that has not yet been opened or has been closed. Note that
-	// RFC 7540 allows PRIORITY frames to be sent on streams in any state. See:
-	// https://tools.ietf.org/html/rfc7540#section-5.1
-	AdjustStream(streamID uint32, priority PriorityParam)
-
-	// Push queues a frame in the scheduler. In most cases, this will not be
-	// called with wr.StreamID()!=0 unless that stream is currently open. The one
-	// exception is RST_STREAM frames, which may be sent on idle or closed streams.
-	Push(wr FrameWriteRequest)
-
-	// Pop dequeues the next frame to write. Returns false if no frames can
-	// be written. Frames with a given wr.StreamID() are Pop'd in the same
-	// order they are Push'd, except RST_STREAM frames. No frames should be
-	// discarded except by CloseStream.
-	Pop() (wr FrameWriteRequest, ok bool)
-}
-
-// OpenStreamOptions specifies extra options for WriteScheduler.OpenStream.
-//
-// Deprecated: User-provided write schedulers are deprecated.
-type OpenStreamOptions struct {
-	// PusherID is zero if the stream was initiated by the client. Otherwise,
-	// PusherID names the stream that pushed the newly opened stream.
-	PusherID uint32
-	// priority is used to set the priority of the newly opened stream.
-	priority PriorityParam
-}
-
 // FrameWriteRequest is a request to write a frame.
 //
 // Deprecated: User-provided write schedulers are deprecated.
@@ -0,0 +1,90 @@
+// Copyright 2026 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http2
+
+// WriteScheduler is the interface implemented by HTTP/2 write schedulers.
+// Methods are never called concurrently.
+//
+// Deprecated: User-provided write schedulers are deprecated.
+type WriteScheduler interface {
+	// OpenStream opens a new stream in the write scheduler.
+	// It is illegal to call this with streamID=0 or with a streamID that is
+	// already open -- the call may panic.
+	OpenStream(streamID uint32, options OpenStreamOptions)
+
+	// CloseStream closes a stream in the write scheduler. Any frames queued on
+	// this stream should be discarded. It is illegal to call this on a stream
+	// that is not open -- the call may panic.
+	CloseStream(streamID uint32)
+
+	// AdjustStream adjusts the priority of the given stream. This may be called
+	// on a stream that has not yet been opened or has been closed. Note that
+	// RFC 7540 allows PRIORITY frames to be sent on streams in any state. See:
+	// https://tools.ietf.org/html/rfc7540#section-5.1
+	AdjustStream(streamID uint32, priority PriorityParam)
+
+	// Push queues a frame in the scheduler. In most cases, this will not be
+	// called with wr.StreamID()!=0 unless that stream is currently open. The one
+	// exception is RST_STREAM frames, which may be sent on idle or closed streams.
+	Push(wr FrameWriteRequest)
+
+	// Pop dequeues the next frame to write. Returns false if no frames can
+	// be written. Frames with a given wr.StreamID() are Pop'd in the same
+	// order they are Push'd, except RST_STREAM frames. No frames should be
+	// discarded except by CloseStream.
+	Pop() (wr FrameWriteRequest, ok bool)
+}
+
+// OpenStreamOptions specifies extra options for WriteScheduler.OpenStream.
+//
+// Deprecated: User-provided write schedulers are deprecated.
+type OpenStreamOptions struct {
+	// PusherID is zero if the stream was initiated by the client. Otherwise,
+	// PusherID names the stream that pushed the newly opened stream.
+	PusherID uint32
+	// priority is used to set the priority of the newly opened stream.
+	priority PriorityParam
+}
+
+// PriorityWriteSchedulerConfig configures a priorityWriteScheduler.
+//
+// Deprecated: User-provided write schedulers are deprecated.
+type PriorityWriteSchedulerConfig struct {
+	// MaxClosedNodesInTree controls the maximum number of closed streams to
+	// retain in the priority tree. Setting this to zero saves a small amount
+	// of memory at the cost of performance.
+	//
+	// See RFC 7540, Section 5.3.4:
+	//   "It is possible for a stream to become closed while prioritization
+	//   information ... is in transit. ... This potentially creates suboptimal
+	//   prioritization, since the stream could be given a priority that is
+	//   different from what is intended. To avoid these problems, an endpoint
+	//   SHOULD retain stream prioritization state for a period after streams
+	//   become closed. The longer state is retained, the lower the chance that
+	//   streams are assigned incorrect or default priority values."
+	MaxClosedNodesInTree int
+
+	// MaxIdleNodesInTree controls the maximum number of idle streams to
+	// retain in the priority tree. Setting this to zero saves a small amount
+	// of memory at the cost of performance.
+	//
+	// See RFC 7540, Section 5.3.4:
+	//   Similarly, streams that are in the "idle" state can be assigned
+	//   priority or become a parent of other streams. This allows for the
+	//   creation of a grouping node in the dependency tree, which enables
+	//   more flexible expressions of priority. Idle streams begin with a
+	//   default priority (Section 5.3.5).
+	MaxIdleNodesInTree int
+
+	// ThrottleOutOfOrderWrites enables write throttling to help ensure that
+	// data is delivered in priority order. This works around a race where
+	// stream B depends on stream A and both streams are about to call Write
+	// to queue DATA frames. If B wins the race, a naive scheduler would eagerly
+	// write as much data from B as possible, but this is suboptimal because A
+	// is a higher-priority stream. With throttling enabled, we write a small
+	// amount of data from B to minimize the amount of bandwidth that B can
+	// steal from A.
+	ThrottleOutOfOrderWrites bool
+}
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

+//go:build !(go1.27 && !http2legacy)
+
 package http2

 import (
@@ -13,47 +15,6 @@ import (
 // RFC 7540, Section 5.3.5: the default weight is 16.
 const priorityDefaultWeightRFC7540 = 15 // 16 = 15 + 1

-// PriorityWriteSchedulerConfig configures a priorityWriteScheduler.
-//
-// Deprecated: User-provided write schedulers are deprecated.
-type PriorityWriteSchedulerConfig struct {
-	// MaxClosedNodesInTree controls the maximum number of closed streams to
-	// retain in the priority tree. Setting this to zero saves a small amount
-	// of memory at the cost of performance.
-	//
-	// See RFC 7540, Section 5.3.4:
-	//   "It is possible for a stream to become closed while prioritization
-	//   information ... is in transit. ... This potentially creates suboptimal
-	//   prioritization, since the stream could be given a priority that is
-	//   different from what is intended. To avoid these problems, an endpoint
-	//   SHOULD retain stream prioritization state for a period after streams
-	//   become closed. The longer state is retained, the lower the chance that
-	//   streams are assigned incorrect or default priority values."
-	MaxClosedNodesInTree int
-
-	// MaxIdleNodesInTree controls the maximum number of idle streams to
-	// retain in the priority tree. Setting this to zero saves a small amount
-	// of memory at the cost of performance.
-	//
-	// See RFC 7540, Section 5.3.4:
-	//   Similarly, streams that are in the "idle" state can be assigned
-	//   priority or become a parent of other streams. This allows for the
-	//   creation of a grouping node in the dependency tree, which enables
-	//   more flexible expressions of priority. Idle streams begin with a
-	//   default priority (Section 5.3.5).
-	MaxIdleNodesInTree int
-
-	// ThrottleOutOfOrderWrites enables write throttling to help ensure that
-	// data is delivered in priority order. This works around a race where
-	// stream B depends on stream A and both streams are about to call Write
-	// to queue DATA frames. If B wins the race, a naive scheduler would eagerly
-	// write as much data from B as possible, but this is suboptimal because A
-	// is a higher-priority stream. With throttling enabled, we write a small
-	// amount of data from B to minimize the amount of bandwidth that B can
-	// steal from A.
-	ThrottleOutOfOrderWrites bool
-}
-
 // NewPriorityWriteScheduler constructs a WriteScheduler that schedules
 // frames by following HTTP/2 priorities as described in RFC 7540 Section 5.3.
 // If cfg is nil, default options are used.
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

+//go:build !(go1.27 && !http2legacy)
+
 package http2

 import (
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

+//go:build !(go1.27 && !http2legacy)
+
 package http2

 import "math"
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

+//go:build !(go1.27 && !http2legacy)
+
 package http2

 import (
@@ -1,13 +0,0 @@
-// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
-
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build go1.18
-
-package idna
-
-// Transitional processing is disabled by default in Go 1.18.
-// https://golang.org/issue/47510
-const transitionalLookup = false
@@ -4,8 +4,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

-//go:build go1.10
-
 // Package idna implements IDNA2008 using the compatibility processing
 // defined by UTS (Unicode Technical Standard) #46, which defines a standard to
 // deal with the transition from IDNA2003.
@@ -20,6 +18,7 @@ package idna // import "golang.org/x/net/idna"
 import (
 	"fmt"
 	"strings"
+	"unicode"
 	"unicode/utf8"

 	"golang.org/x/text/secure/bidirule"
@@ -27,6 +26,8 @@ import (
 	"golang.org/x/text/unicode/norm"
 )

+const unicode16 = unicode.Version >= "16.0.0"
+
 // NOTE: Unlike common practice in Go APIs, the functions will return a
 // sanitized domain name in case of errors. Browsers sometimes use a partially
 // evaluated string as lookup.
@@ -101,6 +102,11 @@ func ValidateLabels(enable bool) Option {
 	}
 }

+// validateLabels reports whether the ValidateLabels option is enabled.
+func (p *Profile) validateLabels() bool {
+	return p.fromPuny != nil
+}
+
 // CheckHyphens sets whether to check for correct use of hyphens ('-') in
 // labels. Most web browsers do not have this option set, since labels such as
 // "r3---sn-apo3qvuoxuxbt-j5pe" are in common use.
@@ -263,6 +269,10 @@ func (p *Profile) String() string {
 	return s
 }

+// Transitional processing is disabled by default as of Go 1.18.
+// https://golang.org/issue/47510
+const transitionalLookup = false
+
 var (
 	// Punycode is a Profile that does raw punycode processing with a minimum
 	// of validation.
@@ -324,15 +334,30 @@ func (e labelError) Error() string {
 	return fmt.Sprintf("idna: invalid label %q", e.label)
 }

-type runeError rune
-
-func (e runeError) code() string { return "P1" }
-func (e runeError) Error() string {
-	return fmt.Sprintf("idna: disallowed rune %U", e)
+type runeError struct {
+	r     rune
+	code_ string
 }

-// process implements the algorithm described in section 4 of UTS #46,
-// see https://www.unicode.org/reports/tr46.
+func (e runeError) code() string { return e.code_ }
+func (e runeError) Error() string {
+	return fmt.Sprintf("idna: disallowed rune %U", e.r)
+}
+
+// code16 returns old for Unicode < 16, new for Unicode >= 16.
+func code16(old, new string) string {
+	if unicode16 {
+		return new
+	}
+	return old
+}
+
+// process10 implements the algorithm described in section 4 of UTS #46.
+// It implements both the Unicode 10 algorithm
+// (https://www.unicode.org/reports/tr46/tr46-19.html)
+// and the Unicode 16 algorithm
+// (https://www.unicode.org/reports/tr46/tr46-35.html)
+// depending on unicode16, which in turn depends on unicode.Version.
 func (p *Profile) process(s string, toASCII bool) (string, error) {
 	var err error
 	var isBidi bool
@@ -347,8 +372,12 @@ func (p *Profile) process(s string, toASCII bool) (string, error) {
 	// TODO: allow for a quick check of the tables data.
 	// It seems like we should only create this error on ToASCII, but the
 	// UTS 46 conformance tests suggests we should always check this.
+	labelCode := "X4_2"
+	if !unicode16 || toASCII {
+		labelCode = "A4"
+	}
 	if err == nil && p.verifyDNSLength && s == "" {
-		err = &labelError{s, "A4"}
+		err = labelError{s, labelCode}
 	}
 	labels := labelIter{orig: s}
 	for ; !labels.done(); labels.next() {
@@ -357,12 +386,13 @@ func (p *Profile) process(s string, toASCII bool) (string, error) {
 			// Empty labels are not okay. The label iterator skips the last
 			// label if it is empty.
 			if err == nil && p.verifyDNSLength {
-				err = &labelError{s, "A4"}
+				err = labelError{s, labelCode}
 			}
 			continue
 		}
 		if strings.HasPrefix(label, acePrefix) {
-			u, err2 := decode(label[len(acePrefix):])
+			enc := label[len(acePrefix):]
+			u, err2 := decode(enc)
 			if err2 != nil {
 				if err == nil {
 					err = err2
@@ -370,6 +400,9 @@ func (p *Profile) process(s string, toASCII bool) (string, error) {
 				// Spec says keep the old label.
 				continue
 			}
+			if unicode16 && err == nil && len(u) > 0 && isASCII(u) {
+				err = punyError(enc)
+			}
 			isBidi = isBidi || bidirule.DirectionString(u) != bidi.LeftToRight
 			labels.set(u)
 			if err == nil && p.fromPuny != nil {
@@ -379,16 +412,16 @@ func (p *Profile) process(s string, toASCII bool) (string, error) {
 				// This should be called on NonTransitional, according to the
 				// spec, but that currently does not have any effect. Use the
 				// original profile to preserve options.
-				err = p.validateLabel(u)
+				err = p.validateLabel(u, labelCode)
 			}
 		} else if err == nil {
-			err = p.validateLabel(label)
+			err = p.validateLabel(label, labelCode)
 		}
 	}
 	if isBidi && p.bidirule != nil && err == nil {
 		for labels.reset(); !labels.done(); labels.next() {
 			if !p.bidirule(labels.label()) {
-				err = &labelError{s, "B"}
+				err = labelError{s, "B"}
 				break
 			}
 		}
@@ -406,24 +439,36 @@ func (p *Profile) process(s string, toASCII bool) (string, error) {
 			}
 			n := len(label)
 			if p.verifyDNSLength && err == nil && (n == 0 || n > 63) {
-				err = &labelError{label, "A4"}
+				err = labelError{label, labelCode}
 			}
 		}
 	}
 	s = labels.result()
 	if toASCII && p.verifyDNSLength && err == nil {
+		if unicode16 && strings.HasSuffix(s, ".") {
+			err = labelError{s, labelCode}
+		}
 		// Compute the length of the domain name minus the root label and its dot.
 		n := len(s)
 		if n > 0 && s[n-1] == '.' {
 			n--
 		}
 		if len(s) < 1 || n > 253 {
-			err = &labelError{s, "A4"}
+			err = labelError{s, labelCode}
 		}
 	}
 	return s, err
 }

+func isASCII(s string) bool {
+	for _, c := range []byte(s) {
+		if c >= 0x80 {
+			return false
+		}
+	}
+	return true
+}
+
 func normalize(p *Profile, s string) (mapped string, isBidi bool, err error) {
 	// TODO: consider first doing a quick check to see if any of these checks
 	// need to be done. This will make it slower in the general case, but
@@ -436,12 +481,12 @@ func normalize(p *Profile, s string) (mapped string, isBidi bool, err error) {
 func validateRegistration(p *Profile, s string) (idem string, bidi bool, err error) {
 	// TODO: filter need for normalization in loop below.
 	if !norm.NFC.IsNormalString(s) {
-		return s, false, &labelError{s, "V1"}
+		return s, false, labelError{s, "V1"}
 	}
 	for i := 0; i < len(s); {
 		v, sz := trie.lookupString(s[i:])
 		if sz == 0 {
-			return s, bidi, runeError(utf8.RuneError)
+			return s, bidi, runeError{utf8.RuneError, "P1"}
 		}
 		bidi = bidi || info(v).isBidi(s[i:])
 		// Copy bytes not copied so far.
@@ -449,9 +494,12 @@ func validateRegistration(p *Profile, s string) (idem string, bidi bool, err err
 		// TODO: handle the NV8 defined in the Unicode idna data set to allow
 		// for strict conformance to IDNA2008.
 		case valid, deviation:
+			if sz == 1 && p.useSTD3Rules && !allowedSTD3(rune(s[i])) {
+				return s, bidi, runeError{rune(s[i]), "P1"}
+			}
 		case disallowed, mapped, unknown, ignored:
 			r, _ := utf8.DecodeRuneInString(s[i:])
-			return s, bidi, runeError(r)
+			return s, bidi, runeError{r, "P1"}
 		}
 		i += sz
 	}
@@ -489,7 +537,7 @@ func validateAndMap(p *Profile, s string) (vm string, bidi bool, err error) {
 			b = append(b, "\ufffd"...)
 			k = len(s)
 			if err == nil {
-				err = runeError(utf8.RuneError)
+				err = runeError{utf8.RuneError, "P1"}
 			}
 			break
 		}
@@ -502,14 +550,26 @@ func validateAndMap(p *Profile, s string) (vm string, bidi bool, err error) {
 		case valid:
 			continue
 		case disallowed:
-			if err == nil {
+			// Unicode 16 delays the error until validateLabels.
+			// Unicode 10 gave an error now.
+			if !unicode16 && err == nil {
 				r, _ := utf8.DecodeRuneInString(s[start:])
-				err = runeError(r)
+				err = runeError{r, "P1"}
 			}
 			continue
-		case mapped, deviation:
+		case deviation:
+			if unicode16 && !p.transitional {
+				break
+			}
+			fallthrough
+		case mapped:
 			b = append(b, s[k:start]...)
-			b = info(v).appendMapping(b, s[start:i])
+			// Unicode 16 requires a special case to handle ẞ -> ss in transitional mode.
+			if unicode16 && p.transitional && s[start:start+sz] == "ẞ" {
+				b = append(b, "ss"...)
+			} else {
+				b = info(v).appendMapping(b, s[start:i])
+			}
 		case ignored:
 			b = append(b, s[k:start]...)
 			// drop the rune
@@ -600,13 +660,13 @@ const acePrefix = "xn--"

 func (p *Profile) simplify(cat category) category {
 	switch cat {
-	case disallowedSTD3Mapped:
+	case disallowedSTD3Mapped: // only happens for pre-Unicode 16
 		if p.useSTD3Rules {
 			cat = disallowed
 		} else {
 			cat = mapped
 		}
-	case disallowedSTD3Valid:
+	case disallowedSTD3Valid: // only happens for pre-Unicode 16
 		if p.useSTD3Rules {
 			cat = disallowed
 		} else {
@@ -625,17 +685,18 @@ func (p *Profile) simplify(cat category) category {

 func validateFromPunycode(p *Profile, s string) error {
 	if !norm.NFC.IsNormalString(s) {
-		return &labelError{s, "V1"}
+		return labelError{s, "V1"}
 	}
 	// TODO: detect whether string may have to be normalized in the following
 	// loop.
 	for i := 0; i < len(s); {
 		v, sz := trie.lookupString(s[i:])
 		if sz == 0 {
-			return runeError(utf8.RuneError)
+			return runeError{utf8.RuneError, "P1"}
 		}
-		if c := p.simplify(info(v).category()); c != valid && c != deviation {
-			return &labelError{s, "V6"}
+		cat := info(v).category()
+		if c := p.simplify(cat); c != valid && c != deviation {
+			return labelError{s, code16("V6", "V7")}
 		}
 		i += sz
 	}
@@ -704,23 +765,51 @@ var joinStates = [][numJoinTypes]joinState{
 	},
 }

+// allowedSTD3 reports whether r is a rune that can appear in a domain name
+// according to STD3. We allow all non-ASCII runes and then letters, digits, hyphens.
+// We also add dot so that this can be run against the whole name and not just
+// a single name element (label). The surrounding code checks dots well enough.
+func allowedSTD3(r rune) bool {
+	return r >= 0x80 || 'a' <= r && r <= 'z' || '0' <= r && r <= '9' || r == '-' || r == '.'
+}
+
 // validateLabel validates the criteria from Section 4.1. Item 1, 4, and 6 are
 // already implicitly satisfied by the overall implementation.
-func (p *Profile) validateLabel(s string) (err error) {
+func (p *Profile) validateLabel(s string, labelCode string) (err error) {
 	if s == "" {
 		if p.verifyDNSLength {
-			return &labelError{s, "A4"}
+			return labelError{s, labelCode}
 		}
 		return nil
 	}
 	if p.checkHyphens {
 		if len(s) > 4 && s[2] == '-' && s[3] == '-' {
-			return &labelError{s, "V2"}
+			return labelError{s, "V2"}
 		}
 		if s[0] == '-' || s[len(s)-1] == '-' {
-			return &labelError{s, "V3"}
+			return labelError{s, "V3"}
 		}
 	}
+
+	// Unicode 16's TR 46 delays the rune validity checks until after the label is decoded.
+	// (validateAndMap did not reject them earlier.)
+	if unicode16 && p.validateLabels() {
+		for i := 0; i < len(s); {
+			v, sz := trie.lookupString(s[i:])
+			if sz == 0 {
+				return runeError{utf8.RuneError, "P1"}
+			}
+			cat := info(v).category()
+			if c := p.simplify(cat); c != valid && (!p.transitional || c != deviation) {
+				return labelError{s, "V7"}
+			}
+			if sz == 1 && p.useSTD3Rules && !allowedSTD3(rune(s[i])) {
+				return runeError{rune(s[i]), "U1"}
+			}
+			i += sz
+		}
+	}
+
 	if !p.checkJoiners {
 		return nil
 	}
@@ -729,7 +818,7 @@ func (p *Profile) validateLabel(s string) (err error) {
 	v, sz := trie.lookupString(s)
 	x := info(v)
 	if x.isModifier() {
-		return &labelError{s, "V5"}
+		return labelError{s, code16("V5", "V6")}
 	}
 	// Quickly return in the absence of zero-width (non) joiners.
 	if strings.Index(s, zwj) == -1 && strings.Index(s, zwnj) == -1 {
@@ -754,8 +843,9 @@ func (p *Profile) validateLabel(s string) (err error) {
 		x = info(v)
 	}
 	if st == stateFAIL || st == stateAfter {
-		return &labelError{s, "C"}
+		return labelError{s, "C"}
 	}
+
 	return nil
 }

@@ -767,3 +857,24 @@ func ascii(s string) bool {
 	}
 	return true
 }
+
+// appendMapping appends the mapping for the respective rune. isMapped must be
+// true. A mapping is a categorization of a rune as defined in UTS #46.
+func (c info) appendMapping(b []byte, s string) []byte {
+	index := int(c >> indexShift)
+	if c&xorBit == 0 {
+		p := index
+		return append(b, mappings[mappingIndex[p]:mappingIndex[p+1]]...)
+	}
+	b = append(b, s...)
+	if c&inlineXOR == inlineXOR {
+		// TODO: support and handle two-byte inline masks
+		b[len(b)-1] ^= byte(index)
+	} else {
+		for p := len(b) - int(xorData[index]); p < len(b); p++ {
+			index++
+			b[p] ^= xorData[index]
+		}
+	}
+	return b
+}
@@ -1,717 +0,0 @@
-// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
-
-// Copyright 2016 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build !go1.10
-
-// Package idna implements IDNA2008 using the compatibility processing
-// defined by UTS (Unicode Technical Standard) #46, which defines a standard to
-// deal with the transition from IDNA2003.
-//
-// IDNA2008 (Internationalized Domain Names for Applications), is defined in RFC
-// 5890, RFC 5891, RFC 5892, RFC 5893 and RFC 5894.
-// UTS #46 is defined in https://www.unicode.org/reports/tr46.
-// See https://unicode.org/cldr/utility/idna.jsp for a visualization of the
-// differences between these two standards.
-package idna // import "golang.org/x/net/idna"
-
-import (
-	"fmt"
-	"strings"
-	"unicode/utf8"
-
-	"golang.org/x/text/secure/bidirule"
-	"golang.org/x/text/unicode/norm"
-)
-
-// NOTE: Unlike common practice in Go APIs, the functions will return a
-// sanitized domain name in case of errors. Browsers sometimes use a partially
-// evaluated string as lookup.
-// TODO: the current error handling is, in my opinion, the least opinionated.
-// Other strategies are also viable, though:
-// Option 1) Return an empty string in case of error, but allow the user to
-//    specify explicitly which errors to ignore.
-// Option 2) Return the partially evaluated string if it is itself a valid
-//    string, otherwise return the empty string in case of error.
-// Option 3) Option 1 and 2.
-// Option 4) Always return an empty string for now and implement Option 1 as
-//    needed, and document that the return string may not be empty in case of
-//    error in the future.
-// I think Option 1 is best, but it is quite opinionated.
-
-// ToASCII is a wrapper for Punycode.ToASCII.
-func ToASCII(s string) (string, error) {
-	return Punycode.process(s, true)
-}
-
-// ToUnicode is a wrapper for Punycode.ToUnicode.
-func ToUnicode(s string) (string, error) {
-	return Punycode.process(s, false)
-}
-
-// An Option configures a Profile at creation time.
-type Option func(*options)
-
-// Transitional sets a Profile to use the Transitional mapping as defined in UTS
-// #46. This will cause, for example, "ß" to be mapped to "ss". Using the
-// transitional mapping provides a compromise between IDNA2003 and IDNA2008
-// compatibility. It is used by some browsers when resolving domain names. This
-// option is only meaningful if combined with MapForLookup.
-func Transitional(transitional bool) Option {
-	return func(o *options) { o.transitional = transitional }
-}
-
-// VerifyDNSLength sets whether a Profile should fail if any of the IDN parts
-// are longer than allowed by the RFC.
-//
-// This option corresponds to the VerifyDnsLength flag in UTS #46.
-func VerifyDNSLength(verify bool) Option {
-	return func(o *options) { o.verifyDNSLength = verify }
-}
-
-// RemoveLeadingDots removes leading label separators. Leading runes that map to
-// dots, such as U+3002 IDEOGRAPHIC FULL STOP, are removed as well.
-func RemoveLeadingDots(remove bool) Option {
-	return func(o *options) { o.removeLeadingDots = remove }
-}
-
-// ValidateLabels sets whether to check the mandatory label validation criteria
-// as defined in Section 5.4 of RFC 5891. This includes testing for correct use
-// of hyphens ('-'), normalization, validity of runes, and the context rules.
-// In particular, ValidateLabels also sets the CheckHyphens and CheckJoiners flags
-// in UTS #46.
-func ValidateLabels(enable bool) Option {
-	return func(o *options) {
-		// Don't override existing mappings, but set one that at least checks
-		// normalization if it is not set.
-		if o.mapping == nil && enable {
-			o.mapping = normalize
-		}
-		o.trie = trie
-		o.checkJoiners = enable
-		o.checkHyphens = enable
-		if enable {
-			o.fromPuny = validateFromPunycode
-		} else {
-			o.fromPuny = nil
-		}
-	}
-}
-
-// CheckHyphens sets whether to check for correct use of hyphens ('-') in
-// labels. Most web browsers do not have this option set, since labels such as
-// "r3---sn-apo3qvuoxuxbt-j5pe" are in common use.
-//
-// This option corresponds to the CheckHyphens flag in UTS #46.
-func CheckHyphens(enable bool) Option {
-	return func(o *options) { o.checkHyphens = enable }
-}
-
-// CheckJoiners sets whether to check the ContextJ rules as defined in Appendix
-// A of RFC 5892, concerning the use of joiner runes.
-//
-// This option corresponds to the CheckJoiners flag in UTS #46.
-func CheckJoiners(enable bool) Option {
-	return func(o *options) {
-		o.trie = trie
-		o.checkJoiners = enable
-	}
-}
-
-// StrictDomainName limits the set of permissible ASCII characters to those
-// allowed in domain names as defined in RFC 1034 (A-Z, a-z, 0-9 and the
-// hyphen). This is set by default for MapForLookup and ValidateForRegistration,
-// but is only useful if ValidateLabels is set.
-//
-// This option is useful, for instance, for browsers that allow characters
-// outside this range, for example a '_' (U+005F LOW LINE). See
-// http://www.rfc-editor.org/std/std3.txt for more details.
-//
-// This option corresponds to the UseSTD3ASCIIRules flag in UTS #46.
-func StrictDomainName(use bool) Option {
-	return func(o *options) { o.useSTD3Rules = use }
-}
-
-// NOTE: the following options pull in tables. The tables should not be linked
-// in as long as the options are not used.
-
-// BidiRule enables the Bidi rule as defined in RFC 5893. Any application
-// that relies on proper validation of labels should include this rule.
-//
-// This option corresponds to the CheckBidi flag in UTS #46.
-func BidiRule() Option {
-	return func(o *options) { o.bidirule = bidirule.ValidString }
-}
-
-// ValidateForRegistration sets validation options to verify that a given IDN is
-// properly formatted for registration as defined by Section 4 of RFC 5891.
-func ValidateForRegistration() Option {
-	return func(o *options) {
-		o.mapping = validateRegistration
-		StrictDomainName(true)(o)
-		ValidateLabels(true)(o)
-		VerifyDNSLength(true)(o)
-		BidiRule()(o)
-	}
-}
-
-// MapForLookup sets validation and mapping options such that a given IDN is
-// transformed for domain name lookup according to the requirements set out in
-// Section 5 of RFC 5891. The mappings follow the recommendations of RFC 5894,
-// RFC 5895 and UTS 46. It does not add the Bidi Rule. Use the BidiRule option
-// to add this check.
-//
-// The mappings include normalization and mapping case, width and other
-// compatibility mappings.
-func MapForLookup() Option {
-	return func(o *options) {
-		o.mapping = validateAndMap
-		StrictDomainName(true)(o)
-		ValidateLabels(true)(o)
-		RemoveLeadingDots(true)(o)
-	}
-}
-
-type options struct {
-	transitional      bool
-	useSTD3Rules      bool
-	checkHyphens      bool
-	checkJoiners      bool
-	verifyDNSLength   bool
-	removeLeadingDots bool
-
-	trie *idnaTrie
-
-	// fromPuny calls validation rules when converting A-labels to U-labels.
-	fromPuny func(p *Profile, s string) error
-
-	// mapping implements a validation and mapping step as defined in RFC 5895
-	// or UTS 46, tailored to, for example, domain registration or lookup.
-	mapping func(p *Profile, s string) (string, error)
-
-	// bidirule, if specified, checks whether s conforms to the Bidi Rule
-	// defined in RFC 5893.
-	bidirule func(s string) bool
-}
-
-// A Profile defines the configuration of a IDNA mapper.
-type Profile struct {
-	options
-}
-
-func apply(o *options, opts []Option) {
-	for _, f := range opts {
-		f(o)
-	}
-}
-
-// New creates a new Profile.
-//
-// With no options, the returned Profile is the most permissive and equals the
-// Punycode Profile. Options can be passed to further restrict the Profile. The
-// MapForLookup and ValidateForRegistration options set a collection of options,
-// for lookup and registration purposes respectively, which can be tailored by
-// adding more fine-grained options, where later options override earlier
-// options.
-func New(o ...Option) *Profile {
-	p := &Profile{}
-	apply(&p.options, o)
-	return p
-}
-
-// ToASCII converts a domain or domain label to its ASCII form. For example,
-// ToASCII("bücher.example.com") is "xn--bcher-kva.example.com", and
-// ToASCII("golang") is "golang". If an error is encountered it will return
-// an error and a (partially) processed result.
-func (p *Profile) ToASCII(s string) (string, error) {
-	return p.process(s, true)
-}
-
-// ToUnicode converts a domain or domain label to its Unicode form. For example,
-// ToUnicode("xn--bcher-kva.example.com") is "bücher.example.com", and
-// ToUnicode("golang") is "golang". If an error is encountered it will return
-// an error and a (partially) processed result.
-func (p *Profile) ToUnicode(s string) (string, error) {
-	pp := *p
-	pp.transitional = false
-	return pp.process(s, false)
-}
-
-// String reports a string with a description of the profile for debugging
-// purposes. The string format may change with different versions.
-func (p *Profile) String() string {
-	s := ""
-	if p.transitional {
-		s = "Transitional"
-	} else {
-		s = "NonTransitional"
-	}
-	if p.useSTD3Rules {
-		s += ":UseSTD3Rules"
-	}
-	if p.checkHyphens {
-		s += ":CheckHyphens"
-	}
-	if p.checkJoiners {
-		s += ":CheckJoiners"
-	}
-	if p.verifyDNSLength {
-		s += ":VerifyDNSLength"
-	}
-	return s
-}
-
-var (
-	// Punycode is a Profile that does raw punycode processing with a minimum
-	// of validation.
-	Punycode *Profile = punycode
-
-	// Lookup is the recommended profile for looking up domain names, according
-	// to Section 5 of RFC 5891. The exact configuration of this profile may
-	// change over time.
-	Lookup *Profile = lookup
-
-	// Display is the recommended profile for displaying domain names.
-	// The configuration of this profile may change over time.
-	Display *Profile = display
-
-	// Registration is the recommended profile for checking whether a given
-	// IDN is valid for registration, according to Section 4 of RFC 5891.
-	Registration *Profile = registration
-
-	punycode = &Profile{}
-	lookup   = &Profile{options{
-		transitional:      true,
-		removeLeadingDots: true,
-		useSTD3Rules:      true,
-		checkHyphens:      true,
-		checkJoiners:      true,
-		trie:              trie,
-		fromPuny:          validateFromPunycode,
-		mapping:           validateAndMap,
-		bidirule:          bidirule.ValidString,
-	}}
-	display = &Profile{options{
-		useSTD3Rules:      true,
-		removeLeadingDots: true,
-		checkHyphens:      true,
-		checkJoiners:      true,
-		trie:              trie,
-		fromPuny:          validateFromPunycode,
-		mapping:           validateAndMap,
-		bidirule:          bidirule.ValidString,
-	}}
-	registration = &Profile{options{
-		useSTD3Rules:    true,
-		verifyDNSLength: true,
-		checkHyphens:    true,
-		checkJoiners:    true,
-		trie:            trie,
-		fromPuny:        validateFromPunycode,
-		mapping:         validateRegistration,
-		bidirule:        bidirule.ValidString,
-	}}
-
-	// TODO: profiles
-	// Register: recommended for approving domain names: don't do any mappings
-	// but rather reject on invalid input. Bundle or block deviation characters.
-)
-
-type labelError struct{ label, code_ string }
-
-func (e labelError) code() string { return e.code_ }
-func (e labelError) Error() string {
-	return fmt.Sprintf("idna: invalid label %q", e.label)
-}
-
-type runeError rune
-
-func (e runeError) code() string { return "P1" }
-func (e runeError) Error() string {
-	return fmt.Sprintf("idna: disallowed rune %U", e)
-}
-
-// process implements the algorithm described in section 4 of UTS #46,
-// see https://www.unicode.org/reports/tr46.
-func (p *Profile) process(s string, toASCII bool) (string, error) {
-	var err error
-	if p.mapping != nil {
-		s, err = p.mapping(p, s)
-	}
-	// Remove leading empty labels.
-	if p.removeLeadingDots {
-		for ; len(s) > 0 && s[0] == '.'; s = s[1:] {
-		}
-	}
-	// It seems like we should only create this error on ToASCII, but the
-	// UTS 46 conformance tests suggests we should always check this.
-	if err == nil && p.verifyDNSLength && s == "" {
-		err = &labelError{s, "A4"}
-	}
-	labels := labelIter{orig: s}
-	for ; !labels.done(); labels.next() {
-		label := labels.label()
-		if label == "" {
-			// Empty labels are not okay. The label iterator skips the last
-			// label if it is empty.
-			if err == nil && p.verifyDNSLength {
-				err = &labelError{s, "A4"}
-			}
-			continue
-		}
-		if strings.HasPrefix(label, acePrefix) {
-			u, err2 := decode(label[len(acePrefix):])
-			if err2 != nil {
-				if err == nil {
-					err = err2
-				}
-				// Spec says keep the old label.
-				continue
-			}
-			labels.set(u)
-			if err == nil && p.fromPuny != nil {
-				err = p.fromPuny(p, u)
-			}
-			if err == nil {
-				// This should be called on NonTransitional, according to the
-				// spec, but that currently does not have any effect. Use the
-				// original profile to preserve options.
-				err = p.validateLabel(u)
-			}
-		} else if err == nil {
-			err = p.validateLabel(label)
-		}
-	}
-	if toASCII {
-		for labels.reset(); !labels.done(); labels.next() {
-			label := labels.label()
-			if !ascii(label) {
-				a, err2 := encode(acePrefix, label)
-				if err == nil {
-					err = err2
-				}
-				label = a
-				labels.set(a)
-			}
-			n := len(label)
-			if p.verifyDNSLength && err == nil && (n == 0 || n > 63) {
-				err = &labelError{label, "A4"}
-			}
-		}
-	}
-	s = labels.result()
-	if toASCII && p.verifyDNSLength && err == nil {
-		// Compute the length of the domain name minus the root label and its dot.
-		n := len(s)
-		if n > 0 && s[n-1] == '.' {
-			n--
-		}
-		if len(s) < 1 || n > 253 {
-			err = &labelError{s, "A4"}
-		}
-	}
-	return s, err
-}
-
-func normalize(p *Profile, s string) (string, error) {
-	return norm.NFC.String(s), nil
-}
-
-func validateRegistration(p *Profile, s string) (string, error) {
-	if !norm.NFC.IsNormalString(s) {
-		return s, &labelError{s, "V1"}
-	}
-	for i := 0; i < len(s); {
-		v, sz := trie.lookupString(s[i:])
-		// Copy bytes not copied so far.
-		switch p.simplify(info(v).category()) {
-		// TODO: handle the NV8 defined in the Unicode idna data set to allow
-		// for strict conformance to IDNA2008.
-		case valid, deviation:
-		case disallowed, mapped, unknown, ignored:
-			r, _ := utf8.DecodeRuneInString(s[i:])
-			return s, runeError(r)
-		}
-		i += sz
-	}
-	return s, nil
-}
-
-func validateAndMap(p *Profile, s string) (string, error) {
-	var (
-		err error
-		b   []byte
-		k   int
-	)
-	for i := 0; i < len(s); {
-		v, sz := trie.lookupString(s[i:])
-		start := i
-		i += sz
-		// Copy bytes not copied so far.
-		switch p.simplify(info(v).category()) {
-		case valid:
-			continue
-		case disallowed:
-			if err == nil {
-				r, _ := utf8.DecodeRuneInString(s[start:])
-				err = runeError(r)
-			}
-			continue
-		case mapped, deviation:
-			b = append(b, s[k:start]...)
-			b = info(v).appendMapping(b, s[start:i])
-		case ignored:
-			b = append(b, s[k:start]...)
-			// drop the rune
-		case unknown:
-			b = append(b, s[k:start]...)
-			b = append(b, "\ufffd"...)
-		}
-		k = i
-	}
-	if k == 0 {
-		// No changes so far.
-		s = norm.NFC.String(s)
-	} else {
-		b = append(b, s[k:]...)
-		if norm.NFC.QuickSpan(b) != len(b) {
-			b = norm.NFC.Bytes(b)
-		}
-		// TODO: the punycode converters require strings as input.
-		s = string(b)
-	}
-	return s, err
-}
-
-// A labelIter allows iterating over domain name labels.
-type labelIter struct {
-	orig     string
-	slice    []string
-	curStart int
-	curEnd   int
-	i        int
-}
-
-func (l *labelIter) reset() {
-	l.curStart = 0
-	l.curEnd = 0
-	l.i = 0
-}
-
-func (l *labelIter) done() bool {
-	return l.curStart >= len(l.orig)
-}
-
-func (l *labelIter) result() string {
-	if l.slice != nil {
-		return strings.Join(l.slice, ".")
-	}
-	return l.orig
-}
-
-func (l *labelIter) label() string {
-	if l.slice != nil {
-		return l.slice[l.i]
-	}
-	p := strings.IndexByte(l.orig[l.curStart:], '.')
-	l.curEnd = l.curStart + p
-	if p == -1 {
-		l.curEnd = len(l.orig)
-	}
-	return l.orig[l.curStart:l.curEnd]
-}
-
-// next sets the value to the next label. It skips the last label if it is empty.
-func (l *labelIter) next() {
-	l.i++
-	if l.slice != nil {
-		if l.i >= len(l.slice) || l.i == len(l.slice)-1 && l.slice[l.i] == "" {
-			l.curStart = len(l.orig)
-		}
-	} else {
-		l.curStart = l.curEnd + 1
-		if l.curStart == len(l.orig)-1 && l.orig[l.curStart] == '.' {
-			l.curStart = len(l.orig)
-		}
-	}
-}
-
-func (l *labelIter) set(s string) {
-	if l.slice == nil {
-		l.slice = strings.Split(l.orig, ".")
-	}
-	l.slice[l.i] = s
-}
-
-// acePrefix is the ASCII Compatible Encoding prefix.
-const acePrefix = "xn--"
-
-func (p *Profile) simplify(cat category) category {
-	switch cat {
-	case disallowedSTD3Mapped:
-		if p.useSTD3Rules {
-			cat = disallowed
-		} else {
-			cat = mapped
-		}
-	case disallowedSTD3Valid:
-		if p.useSTD3Rules {
-			cat = disallowed
-		} else {
-			cat = valid
-		}
-	case deviation:
-		if !p.transitional {
-			cat = valid
-		}
-	case validNV8, validXV8:
-		// TODO: handle V2008
-		cat = valid
-	}
-	return cat
-}
-
-func validateFromPunycode(p *Profile, s string) error {
-	if !norm.NFC.IsNormalString(s) {
-		return &labelError{s, "V1"}
-	}
-	for i := 0; i < len(s); {
-		v, sz := trie.lookupString(s[i:])
-		if c := p.simplify(info(v).category()); c != valid && c != deviation {
-			return &labelError{s, "V6"}
-		}
-		i += sz
-	}
-	return nil
-}
-
-const (
-	zwnj = "\u200c"
-	zwj  = "\u200d"
-)
-
-type joinState int8
-
-const (
-	stateStart joinState = iota
-	stateVirama
-	stateBefore
-	stateBeforeVirama
-	stateAfter
-	stateFAIL
-)
-
-var joinStates = [][numJoinTypes]joinState{
-	stateStart: {
-		joiningL:   stateBefore,
-		joiningD:   stateBefore,
-		joinZWNJ:   stateFAIL,
-		joinZWJ:    stateFAIL,
-		joinVirama: stateVirama,
-	},
-	stateVirama: {
-		joiningL: stateBefore,
-		joiningD: stateBefore,
-	},
-	stateBefore: {
-		joiningL:   stateBefore,
-		joiningD:   stateBefore,
-		joiningT:   stateBefore,
-		joinZWNJ:   stateAfter,
-		joinZWJ:    stateFAIL,
-		joinVirama: stateBeforeVirama,
-	},
-	stateBeforeVirama: {
-		joiningL: stateBefore,
-		joiningD: stateBefore,
-		joiningT: stateBefore,
-	},
-	stateAfter: {
-		joiningL:   stateFAIL,
-		joiningD:   stateBefore,
-		joiningT:   stateAfter,
-		joiningR:   stateStart,
-		joinZWNJ:   stateFAIL,
-		joinZWJ:    stateFAIL,
-		joinVirama: stateAfter, // no-op as we can't accept joiners here
-	},
-	stateFAIL: {
-		0:          stateFAIL,
-		joiningL:   stateFAIL,
-		joiningD:   stateFAIL,
-		joiningT:   stateFAIL,
-		joiningR:   stateFAIL,
-		joinZWNJ:   stateFAIL,
-		joinZWJ:    stateFAIL,
-		joinVirama: stateFAIL,
-	},
-}
-
-// validateLabel validates the criteria from Section 4.1. Item 1, 4, and 6 are
-// already implicitly satisfied by the overall implementation.
-func (p *Profile) validateLabel(s string) error {
-	if s == "" {
-		if p.verifyDNSLength {
-			return &labelError{s, "A4"}
-		}
-		return nil
-	}
-	if p.bidirule != nil && !p.bidirule(s) {
-		return &labelError{s, "B"}
-	}
-	if p.checkHyphens {
-		if len(s) > 4 && s[2] == '-' && s[3] == '-' {
-			return &labelError{s, "V2"}
-		}
-		if s[0] == '-' || s[len(s)-1] == '-' {
-			return &labelError{s, "V3"}
-		}
-	}
-	if !p.checkJoiners {
-		return nil
-	}
-	trie := p.trie // p.checkJoiners is only set if trie is set.
-	// TODO: merge the use of this in the trie.
-	v, sz := trie.lookupString(s)
-	x := info(v)
-	if x.isModifier() {
-		return &labelError{s, "V5"}
-	}
-	// Quickly return in the absence of zero-width (non) joiners.
-	if strings.Index(s, zwj) == -1 && strings.Index(s, zwnj) == -1 {
-		return nil
-	}
-	st := stateStart
-	for i := 0; ; {
-		jt := x.joinType()
-		if s[i:i+sz] == zwj {
-			jt = joinZWJ
-		} else if s[i:i+sz] == zwnj {
-			jt = joinZWNJ
-		}
-		st = joinStates[st][jt]
-		if x.isViramaModifier() {
-			st = joinStates[st][joinVirama]
-		}
-		if i += sz; i == len(s) {
-			break
-		}
-		v, sz = trie.lookupString(s[i:])
-		x = info(v)
-	}
-	if st == stateFAIL || st == stateAfter {
-		return &labelError{s, "C"}
-	}
-	return nil
-}
-
-func ascii(s string) bool {
-	for i := 0; i < len(s); i++ {
-		if s[i] >= utf8.RuneSelf {
-			return false
-		}
-	}
-	return true
-}
@@ -1,11 +0,0 @@
-// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
-
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build !go1.18
-
-package idna
-
-const transitionalLookup = true
@@ -28,7 +28,7 @@ const (
 	tmin        int32 = 1
 )

-func punyError(s string) error { return &labelError{s, "A3"} }
+func punyError(s string) error { return &labelError{s, code16("A3", "P4")} }

 // decode decodes a string as specified in section 6.2.
 func decode(encoded string) (string, error) {
@@ -108,6 +108,9 @@ func encode(prefix, s string) (string, error) {
 	delta, n, bias := int32(0), initialN, initialBias
 	b, remaining := int32(0), int32(0)
 	for _, r := range s {
+		if unicode16 && r == 0xfffd {
+			return s, &labelError{s, "A3"}
+		}
 		if r < 0x80 {
 			b++
 			output = append(output, byte(r))
@@ -1,6 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.

-//go:build go1.21
+//go:build !go1.27

 package idna

@@ -1,30 +0,0 @@
-// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
-
-// Copyright 2016 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build !go1.16
-
-package idna
-
-// appendMapping appends the mapping for the respective rune. isMapped must be
-// true. A mapping is a categorization of a rune as defined in UTS #46.
-func (c info) appendMapping(b []byte, s string) []byte {
-	index := int(c >> indexShift)
-	if c&xorBit == 0 {
-		s := mappings[index:]
-		return append(b, s[1:s[0]+1]...)
-	}
-	b = append(b, s...)
-	if c&inlineXOR == inlineXOR {
-		// TODO: support and handle two-byte inline masks
-		b[len(b)-1] ^= byte(index)
-	} else {
-		for p := len(b) - int(xorData[index]); p < len(b); p++ {
-			index++
-			b[p] ^= xorData[index]
-		}
-	}
-	return b
-}
@@ -1,30 +0,0 @@
-// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
-
-// Copyright 2016 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build go1.16
-
-package idna
-
-// appendMapping appends the mapping for the respective rune. isMapped must be
-// true. A mapping is a categorization of a rune as defined in UTS #46.
-func (c info) appendMapping(b []byte, s string) []byte {
-	index := int(c >> indexShift)
-	if c&xorBit == 0 {
-		p := index
-		return append(b, mappings[mappingIndex[p]:mappingIndex[p+1]]...)
-	}
-	b = append(b, s...)
-	if c&inlineXOR == inlineXOR {
-		// TODO: support and handle two-byte inline masks
-		b[len(b)-1] ^= byte(index)
-	} else {
-		for p := len(b) - int(xorData[index]); p < len(b); p++ {
-			index++
-			b[p] ^= xorData[index]
-		}
-	}
-	return b
-}
@@ -448,6 +448,14 @@ func NewServerRequest(rp ServerRequestParam) ServerRequestResult {
 		url_ = &url.URL{Host: rp.Authority}
 		requestURI = rp.Authority // mimic HTTP/1 server behavior
 	} else {
+		// "[The :path] pseudo-header field MUST NOT be empty [...]"
+		// https://www.rfc-editor.org/rfc/rfc9113.html#section-8.3.1-2.4.2
+		if rp.Path == "" || (rp.Path[0] != '/' && rp.Path != "*") {
+			return ServerRequestResult{
+				InvalidReason: "bad_path",
+			}
+		}
+
 		var err error
 		url_, err = url.ParseRequestURI(rp.Path)
 		if err != nil {
@@ -6,38 +6,50 @@ package cpu

 import "strconv"

-// parseRelease parses a dot-separated version number. It follows the semver
-// syntax, but allows the minor and patch versions to be elided.
+// parseRelease parses a dot-separated version number from the prefix
+// of rel. It returns ok=true only if at least the major and minor
+// components were successfully parsed; the patch component is
+// best-effort. Trailing vendor or build suffixes such as
+// "-generic", "+", "_hi3535", or "-rc1" are ignored.
 //
 // This is a copy of the Go runtime's parseRelease from
-// https://golang.org/cl/209597.
+// https://golang.org/cl/209597, updated in https://golang.org/cl/781800.
 func parseRelease(rel string) (major, minor, patch int, ok bool) {
-	// Strip anything after a dash or plus.
-	for i := range len(rel) {
-		if rel[i] == '-' || rel[i] == '+' {
-			rel = rel[:i]
-			break
+	// next consumes a run of decimal digits from the front of rel,
+	// returning the parsed value. If the digits are followed by a
+	// '.', it is consumed and more is set so the caller knows to
+	// parse another component; otherwise scanning terminates and
+	// the rest of rel is discarded.
+	next := func() (n int, more, ok bool) {
+		i := 0
+		for i < len(rel) && rel[i] >= '0' && rel[i] <= '9' {
+			i++
 		}
+		if i == 0 {
+			return 0, false, false
+		}
+		n, err := strconv.Atoi(rel[:i])
+		if err != nil {
+			return 0, false, false
+		}
+		if i < len(rel) && rel[i] == '.' {
+			rel = rel[i+1:]
+			return n, true, true
+		}
+		rel = ""
+		return n, false, true
 	}

-	next := func() (int, bool) {
-		for i := range len(rel) {
-			if rel[i] == '.' {
-				ver, err := strconv.Atoi(rel[:i])
-				rel = rel[i+1:]
-				return ver, err == nil
-			}
-		}
-		ver, err := strconv.Atoi(rel)
-		rel = ""
-		return ver, err == nil
+	var more bool
+	if major, more, ok = next(); !ok || !more {
+		return 0, 0, 0, false
 	}
-	if major, ok = next(); !ok || rel == "" {
-		return
+	if minor, more, ok = next(); !ok {
+		return 0, 0, 0, false
 	}
-	if minor, ok = next(); !ok || rel == "" {
-		return
+	if !more {
+		return major, minor, 0, true
 	}
-	patch, ok = next()
-	return
+	patch, _, _ = next()
+	return major, minor, patch, true
 }
@@ -1874,6 +1874,7 @@ func Dup2(oldfd, newfd int) error {
 //sys	Dup3(oldfd int, newfd int, flags int) (err error)
 //sysnb	EpollCreate1(flag int) (fd int, err error)
 //sysnb	EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error)
+//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) = SYS_EPOLL_PWAIT
 //sys	Eventfd(initval uint, flags int) (fd int, err error) = SYS_EVENTFD2
 //sys	Exit(code int) = SYS_EXIT_GROUP
 //sys	Fallocate(fd int, mode uint32, off int64, len int64) (err error)
@@ -20,7 +20,6 @@ func setTimeval(sec, usec int64) Timeval {

 // 64-bit file system and 32-bit uid calls
 // (386 default is 32-bit file system and 16-bit uid).
-//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64_64
 //sys	Fchown(fd int, uid int, gid int) (err error) = SYS_FCHOWN32
 //sys	Fstat(fd int, stat *Stat_t) (err error) = SYS_FSTAT64
@@ -6,7 +6,6 @@

 package unix

-//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
 //sys	Fstat(fd int, stat *Stat_t) (err error)
@@ -44,7 +44,6 @@ func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {

 // 64-bit file system and 32-bit uid calls
 // (16-bit uid calls are not always supported in newer kernels)
-//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fchown(fd int, uid int, gid int) (err error) = SYS_FCHOWN32
 //sys	Fstat(fd int, stat *Stat_t) (err error) = SYS_FSTAT64
 //sys	Fstatat(dirfd int, path string, stat *Stat_t, flags int) (err error) = SYS_FSTATAT64
@@ -8,7 +8,6 @@ package unix

 import "unsafe"

-//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) = SYS_EPOLL_PWAIT
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
 //sys	Fstat(fd int, stat *Stat_t) (err error)
@@ -8,7 +8,6 @@ package unix

 import "unsafe"

-//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) = SYS_EPOLL_PWAIT
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
 //sys	Fstatfs(fd int, buf *Statfs_t) (err error)
@@ -6,7 +6,6 @@

 package unix

-//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
 //sys	Fstatfs(fd int, buf *Statfs_t) (err error)
@@ -13,7 +13,6 @@ import (

 func Syscall9(trap, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr, err syscall.Errno)

-//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
 //sys	Ftruncate(fd int, length int64) (err error) = SYS_FTRUNCATE64
@@ -11,7 +11,6 @@ import (
 	"unsafe"
 )

-//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fchown(fd int, uid int, gid int) (err error)
 //sys	Fstat(fd int, stat *Stat_t) (err error) = SYS_FSTAT64
 //sys	Fstatat(dirfd int, path string, stat *Stat_t, flags int) (err error) = SYS_FSTATAT64
@@ -6,7 +6,6 @@

 package unix

-//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
 //sys	Fstat(fd int, stat *Stat_t) (err error)
@@ -8,7 +8,6 @@ package unix

 import "unsafe"

-//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) = SYS_EPOLL_PWAIT
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
 //sys	Fstat(fd int, stat *Stat_t) (err error)
@@ -10,7 +10,6 @@ import (
 	"unsafe"
 )

-//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
 //sys	Fstat(fd int, stat *Stat_t) (err error)
@@ -6,7 +6,6 @@

 package unix

-//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
 //sys	Fstat(fd int, stat *Stat_t) (err error)
@@ -1359,6 +1359,7 @@ const (
 	FAN_UNLIMITED_MARKS                         = 0x20
 	FAN_UNLIMITED_QUEUE                         = 0x10
 	FD_CLOEXEC                                  = 0x1
+	FD_PIDFS_ROOT                               = -0x2712
 	FD_SETSIZE                                  = 0x400
 	FF0                                         = 0x0
 	FIB_RULE_DEV_DETACHED                       = 0x8
@@ -1970,6 +1971,8 @@ const (
 	MADV_DONTNEED                               = 0x4
 	MADV_DONTNEED_LOCKED                        = 0x18
 	MADV_FREE                                   = 0x8
+	MADV_GUARD_INSTALL                          = 0x66
+	MADV_GUARD_REMOVE                           = 0x67
 	MADV_HUGEPAGE                               = 0xe
 	MADV_HWPOISON                               = 0x64
 	MADV_KEEPONFORK                             = 0x13
@@ -2114,7 +2117,7 @@ const (
 	MS_NOSEC                                    = 0x10000000
 	MS_NOSUID                                   = 0x2
 	MS_NOSYMFOLLOW                              = 0x100
-	MS_NOUSER                                   = -0x80000000
+	MS_NOUSER                                   = 0x80000000
 	MS_POSIXACL                                 = 0x10000
 	MS_PRIVATE                                  = 0x40000
 	MS_RDONLY                                   = 0x1
@@ -3786,6 +3789,9 @@ const (
 	TCPOPT_TIMESTAMP                            = 0x8
 	TCPOPT_TSTAMP_HDR                           = 0x101080a
 	TCPOPT_WINDOW                               = 0x3
+	TCP_AO_KEYF_EXCLUDE_OPT                     = 0x2
+	TCP_AO_KEYF_IFINDEX                         = 0x1
+	TCP_AO_MAXKEYLEN                            = 0x50
 	TCP_CC_INFO                                 = 0x1a
 	TCP_CM_INQ                                  = 0x24
 	TCP_CONGESTION                              = 0xd
@@ -700,6 +700,23 @@ func EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

+func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
+	var _p0 unsafe.Pointer
+	if len(events) > 0 {
+		_p0 = unsafe.Pointer(&events[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	r0, _, e1 := Syscall6(SYS_EPOLL_PWAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
+	n = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Eventfd(initval uint, flags int) (fd int, err error) {
 	r0, _, e1 := Syscall(SYS_EVENTFD2, uintptr(initval), uintptr(flags), 0)
 	fd = int(r0)
@@ -45,23 +45,6 @@ func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_WAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
 	_, _, e1 := Syscall6(SYS_FADVISE64_64, uintptr(fd), uintptr(offset), uintptr(offset>>32), uintptr(length), uintptr(length>>32), uintptr(advice))
 	if e1 != 0 {
@@ -45,23 +45,6 @@ func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_WAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
 	_, _, e1 := Syscall6(SYS_FADVISE64, uintptr(fd), uintptr(offset), uintptr(length), uintptr(advice), 0, 0)
 	if e1 != 0 {
@@ -213,23 +213,6 @@ func sendmsg(s int, msg *Msghdr, flags int) (n int, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_WAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fchown(fd int, uid int, gid int) (err error) {
 	_, _, e1 := Syscall(SYS_FCHOWN32, uintptr(fd), uintptr(uid), uintptr(gid))
 	if e1 != 0 {
@@ -45,23 +45,6 @@ func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_PWAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
 	_, _, e1 := Syscall6(SYS_FADVISE64, uintptr(fd), uintptr(offset), uintptr(length), uintptr(advice), 0, 0)
 	if e1 != 0 {
@@ -45,23 +45,6 @@ func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_PWAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
 	_, _, e1 := Syscall6(SYS_FADVISE64, uintptr(fd), uintptr(offset), uintptr(length), uintptr(advice), 0, 0)
 	if e1 != 0 {
@@ -45,23 +45,6 @@ func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_WAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
 	_, _, e1 := Syscall9(SYS_FADVISE64, uintptr(fd), 0, uintptr(offset>>32), uintptr(offset), uintptr(length>>32), uintptr(length), uintptr(advice), 0, 0)
 	if e1 != 0 {
@@ -45,23 +45,6 @@ func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_WAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
 	_, _, e1 := Syscall6(SYS_FADVISE64, uintptr(fd), uintptr(offset), uintptr(length), uintptr(advice), 0, 0)
 	if e1 != 0 {
@@ -45,23 +45,6 @@ func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_WAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
 	_, _, e1 := Syscall6(SYS_FADVISE64, uintptr(fd), uintptr(offset), uintptr(length), uintptr(advice), 0, 0)
 	if e1 != 0 {
@@ -45,23 +45,6 @@ func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_WAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
 	_, _, e1 := Syscall9(SYS_FADVISE64, uintptr(fd), 0, uintptr(offset), uintptr(offset>>32), uintptr(length), uintptr(length>>32), uintptr(advice), 0, 0)
 	if e1 != 0 {
@@ -45,23 +45,6 @@ func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_WAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fchown(fd int, uid int, gid int) (err error) {
 	_, _, e1 := Syscall(SYS_FCHOWN, uintptr(fd), uintptr(uid), uintptr(gid))
 	if e1 != 0 {
@@ -45,23 +45,6 @@ func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_WAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
 	_, _, e1 := Syscall6(SYS_FADVISE64, uintptr(fd), uintptr(offset), uintptr(length), uintptr(advice), 0, 0)
 	if e1 != 0 {
@@ -45,23 +45,6 @@ func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_WAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
 	_, _, e1 := Syscall6(SYS_FADVISE64, uintptr(fd), uintptr(offset), uintptr(length), uintptr(advice), 0, 0)
 	if e1 != 0 {
@@ -45,23 +45,6 @@ func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_PWAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
 	_, _, e1 := Syscall6(SYS_FADVISE64, uintptr(fd), uintptr(offset), uintptr(length), uintptr(advice), 0, 0)
 	if e1 != 0 {
@@ -45,23 +45,6 @@ func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {

 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

-func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(events) > 0 {
-		_p0 = unsafe.Pointer(&events[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall6(SYS_EPOLL_WAIT, uintptr(epfd), uintptr(_p0), uintptr(len(events)), uintptr(msec), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
 	_, _, e1 := Syscall6(SYS_FADVISE64, uintptr(fd), uintptr(offset), uintptr(length), uintptr(advice), 0, 0)
 	if e1 != 0 {
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
renovate-bot	324993fd25	chore(deps): update dependency codespell to v2.4.3 continuous-integration/drone/push Build is passing Details continuous-integration/drone/pr Build is passing Details	2026-07-29 13:01:17 +00:00
renovate-bot	a1de95a8ce	chore(deps): update module github.com/go-git/go-git/v5 to v5.19.2 continuous-integration/drone/pr Build is passing Details continuous-integration/drone/push Build is passing Details	2026-07-29 12:02:00 +00:00
renovate-bot	f4861bf3c1	chore(deps): update otel/weaver docker tag to v0.25.1 continuous-integration/drone/pr Build is passing Details continuous-integration/drone/push Build is passing Details	2026-07-29 02:00:47 +00:00
renovate-bot	7fb3b2f591	chore(deps): update otel/weaver docker tag to v0.25.0 continuous-integration/drone/push Build is passing Details	2026-07-24 20:01:06 +00:00
renovate-bot	0dec68294f	chore(deps): update nginx docker tag to v1.31.3 continuous-integration/drone/pr Build is passing Details continuous-integration/drone/push Build is passing Details	2026-07-16 02:01:04 +00:00
renovate-bot	69ba548dab	chore(deps): update dependency codespell to v2.4.3 continuous-integration/drone/pr Build is passing Details continuous-integration/drone/push Build is passing Details	2026-07-15 12:00:52 +00:00
renovate-bot	cfa9ff15bb	chore(deps): update golang docker tag continuous-integration/drone/pr Build is passing Details continuous-integration/drone/push Build is passing Details	2026-07-08 18:01:07 +00:00
renovate-bot	ddf7441152	chore(deps): update module golang.org/x/term to v0.45.0 continuous-integration/drone/pr Build is passing Details continuous-integration/drone/push Build is passing Details	2026-07-08 17:01:50 +00:00
renovate-bot	20b4a3fb84	chore(deps): update golang docker tag continuous-integration/drone/pr Build is passing Details continuous-integration/drone/push Build is passing Details	2026-07-08 14:01:06 +00:00
renovate-bot	81f4420a67	chore(deps): update module golang.org/x/sys to v0.47.0 continuous-integration/drone/pr Build is passing Details continuous-integration/drone/push Build is passing Details	2026-07-08 13:01:44 +00:00