Files
docker-cli/vendor/github.com/moby/buildkit/util/sshutil/keyscan.go
Sebastiaan van Stijn 9a0a071d55 vendor: buildkit v0.8.0-rc2, docker
diffs:

- full diff: af34b94a78...6c0a036dce
- full diff: 4d1f260e84...v0.8.0-rc2

New dependencies:

- go.opencensus.io v0.22.3
- github.com/containerd/typeurl v1.0.1
- github.com/golang/groupcache 869f871628b6baa9cfbc11732cdf6546b17c1298

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2020-12-02 21:01:12 +00:00

52 lines
1.2 KiB
Go

package sshutil
import (
"fmt"
"net"
"strconv"
"strings"
"golang.org/x/crypto/ssh"
)
const defaultPort = 22
var errCallbackDone = fmt.Errorf("callback failed on purpose")
// addDefaultPort appends a default port if hostport doesn't contain one
func addDefaultPort(hostport string, defaultPort int) string {
_, _, err := net.SplitHostPort(hostport)
if err == nil {
return hostport
}
hostport = net.JoinHostPort(hostport, strconv.Itoa(defaultPort))
return hostport
}
// SshKeyScan scans a ssh server for the hostkey; server should be in the form hostname, or hostname:port
func SSHKeyScan(server string) (string, error) {
var key string
KeyScanCallback := func(hostport string, remote net.Addr, pubKey ssh.PublicKey) error {
hostname, _, err := net.SplitHostPort(hostport)
if err != nil {
return err
}
key = strings.TrimSpace(fmt.Sprintf("%s %s", hostname, string(ssh.MarshalAuthorizedKey(pubKey))))
return errCallbackDone
}
config := &ssh.ClientConfig{
HostKeyCallback: KeyScanCallback,
}
server = addDefaultPort(server, defaultPort)
conn, err := ssh.Dial("tcp", server, config)
if key != "" {
// as long as we get the key, the function worked
err = nil
}
if conn != nil {
conn.Close()
}
return key, err
}