chore: make deps, go mod vendor

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/aead_crypter.go

@@ -88,17 +88,20 @@ func (ar *aeadDecrypter) Read(dst []byte) (n int, err error) {
 	if errRead != nil && errRead != io.EOF {
 		return 0, errRead
 	}
-	decrypted, errChunk := ar.openChunk(cipherChunk)
-	if errChunk != nil {
-		return 0, errChunk
-	}
 
-	// Return decrypted bytes, buffering if necessary
-	if len(dst) < len(decrypted) {
-		n = copy(dst, decrypted[:len(dst)])
-		ar.buffer.Write(decrypted[len(dst):])
-	} else {
-		n = copy(dst, decrypted)
+	if len(cipherChunk) > 0 {
+		decrypted, errChunk := ar.openChunk(cipherChunk)
+		if errChunk != nil {
+			return 0, errChunk
+		}
+
+		// Return decrypted bytes, buffering if necessary
+		if len(dst) < len(decrypted) {
+			n = copy(dst, decrypted[:len(dst)])
+			ar.buffer.Write(decrypted[len(dst):])
+		} else {
+			n = copy(dst, decrypted)
+		}
 	}
 
 	// Check final authentication tag
@@ -116,6 +119,12 @@ func (ar *aeadDecrypter) Read(dst []byte) (n int, err error) {
 // checked in the last Read call. In the future, this function could be used to
 // wipe the reader and peeked, decrypted bytes, if necessary.
 func (ar *aeadDecrypter) Close() (err error) {
+	if !ar.eof {
+		errChunk := ar.validateFinalTag(ar.peekedBytes)
+		if errChunk != nil {
+			return errChunk
+		}
+	}
 	return nil
 }
 
@@ -138,7 +147,7 @@ func (ar *aeadDecrypter) openChunk(data []byte) ([]byte, error) {
 	nonce := ar.computeNextNonce()
 	plainChunk, err := ar.aead.Open(nil, nonce, chunk, adata)
 	if err != nil {
-		return nil, err
+		return nil, errors.ErrAEADTagVerification
 	}
 	ar.bytesProcessed += len(plainChunk)
 	if err = ar.aeadCrypter.incrementIndex(); err != nil {
@@ -163,9 +172,8 @@ func (ar *aeadDecrypter) validateFinalTag(tag []byte) error {
 	// ... and total number of encrypted octets
 	adata = append(adata, amountBytes...)
 	nonce := ar.computeNextNonce()
-	_, err := ar.aead.Open(nil, nonce, tag, adata)
-	if err != nil {
-		return err
+	if _, err := ar.aead.Open(nil, nonce, tag, adata); err != nil {
+		return errors.ErrAEADTagVerification
 	}
 	return nil
 }

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/compressed.go

@@ -8,9 +8,10 @@ import (
 	"compress/bzip2"
 	"compress/flate"
 	"compress/zlib"
-	"github.com/ProtonMail/go-crypto/openpgp/errors"
 	"io"
 	"strconv"
+
+	"github.com/ProtonMail/go-crypto/openpgp/errors"
 )
 
 // Compressed represents a compressed OpenPGP packet. The decompressed contents
@@ -39,6 +40,37 @@ type CompressionConfig struct {
 	Level int
 }
 
+// decompressionReader ensures that the whole compression packet is read.
+type decompressionReader struct {
+	compressed   io.Reader
+	decompressed io.ReadCloser
+	readAll      bool
+}
+
+func newDecompressionReader(r io.Reader, decompressor io.ReadCloser) *decompressionReader {
+	return &decompressionReader{
+		compressed:   r,
+		decompressed: decompressor,
+	}
+}
+
+func (dr *decompressionReader) Read(data []byte) (n int, err error) {
+	if dr.readAll {
+		return 0, io.EOF
+	}
+	n, err = dr.decompressed.Read(data)
+	if err == io.EOF {
+		dr.readAll = true
+		// Close the decompressor.
+		if errDec := dr.decompressed.Close(); errDec != nil {
+			return n, errDec
+		}
+		// Consume all remaining data from the compressed packet.
+		consumeAll(dr.compressed)
+	}
+	return n, err
+}
+
 func (c *Compressed) parse(r io.Reader) error {
 	var buf [1]byte
 	_, err := readFull(r, buf[:])
@@ -50,11 +82,15 @@ func (c *Compressed) parse(r io.Reader) error {
 	case 0:
 		c.Body = r
 	case 1:
-		c.Body = flate.NewReader(r)
+		c.Body = newDecompressionReader(r, flate.NewReader(r))
 	case 2:
-		c.Body, err = zlib.NewReader(r)
+		decompressor, err := zlib.NewReader(r)
+		if err != nil {
+			return err
+		}
+		c.Body = newDecompressionReader(r, decompressor)
 	case 3:
-		c.Body = bzip2.NewReader(r)
+		c.Body = newDecompressionReader(r, io.NopCloser(bzip2.NewReader(r)))
 	default:
 		err = errors.UnsupportedError("unknown compression algorithm: " + strconv.Itoa(int(buf[0])))
 	}

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/config.go

@@ -14,6 +14,34 @@ import (
 	"github.com/ProtonMail/go-crypto/openpgp/s2k"
 )
 
+var (
+	defaultRejectPublicKeyAlgorithms = map[PublicKeyAlgorithm]bool{
+		PubKeyAlgoElGamal: true,
+		PubKeyAlgoDSA:     true,
+	}
+	defaultRejectHashAlgorithms = map[crypto.Hash]bool{
+		crypto.MD5:       true,
+		crypto.RIPEMD160: true,
+	}
+	defaultRejectMessageHashAlgorithms = map[crypto.Hash]bool{
+		crypto.SHA1:      true,
+		crypto.MD5:       true,
+		crypto.RIPEMD160: true,
+	}
+	defaultRejectCurves = map[Curve]bool{
+		CurveSecP256k1: true,
+	}
+)
+
+// A global feature flag to indicate v5 support.
+// Can be set via a build tag, e.g.: `go build -tags v5 ./...`
+// If the build tag is missing config_v5.go will set it to true.
+//
+// Disables parsing of v5 keys and v5 signatures.
+// These are non-standard entities, which in the crypto-refresh have been superseded
+// by v6 keys, v6 signatures and SEIPDv2 encrypted data, respectively.
+var V5Disabled = false
+
 // Config collects a number of parameters along with sensible defaults.
 // A nil *Config is valid and results in all default values.
 type Config struct {
@@ -73,9 +101,16 @@ type Config struct {
 	// **Note: using this option may break compatibility with other OpenPGP
 	// implementations, as well as future versions of this library.**
 	AEADConfig *AEADConfig
-	// V5Keys configures version 5 key generation. If false, this package still
-	// supports version 5 keys, but produces version 4 keys.
-	V5Keys bool
+	// V6Keys configures version 6 key generation. If false, this package still
+	// supports version 6 keys, but produces version 4 keys.
+	V6Keys bool
+	// Minimum RSA key size allowed for key generation and message signing, verification and encryption.
+	MinRSABits uint16
+	// Reject insecure algorithms, only works with v2 api
+	RejectPublicKeyAlgorithms   map[PublicKeyAlgorithm]bool
+	RejectHashAlgorithms        map[crypto.Hash]bool
+	RejectMessageHashAlgorithms map[crypto.Hash]bool
+	RejectCurves                map[Curve]bool
 	// "The validity period of the key.  This is the number of seconds after
 	// the key creation time that the key expires.  If this is not present
 	// or has a value of zero, the key never expires.  This is found only on
@@ -104,12 +139,40 @@ type Config struct {
 	// might be no other way than to tolerate the missing MDC. Setting this flag, allows this
 	// mode of operation. It should be considered a measure of last resort.
 	InsecureAllowUnauthenticatedMessages bool
+	// InsecureAllowDecryptionWithSigningKeys allows decryption with keys marked as signing keys in the v2 API.
+	// This setting is potentially insecure, but it is needed as some libraries
+	// ignored key flags when selecting a key for encryption.
+	// Not relevant for the v1 API, as all keys were allowed in decryption.
+	InsecureAllowDecryptionWithSigningKeys bool
 	// KnownNotations is a map of Notation Data names to bools, which controls
 	// the notation names that are allowed to be present in critical Notation Data
 	// signature subpackets.
 	KnownNotations map[string]bool
 	// SignatureNotations is a list of Notations to be added to any signatures.
 	SignatureNotations []*Notation
+	// CheckIntendedRecipients controls, whether the OpenPGP Intended Recipient Fingerprint feature
+	// should be enabled for encryption and decryption.
+	// (See https://www.ietf.org/archive/id/draft-ietf-openpgp-crypto-refresh-12.html#name-intended-recipient-fingerpr).
+	// When the flag is set, encryption produces Intended Recipient Fingerprint signature sub-packets and decryption
+	// checks whether the key it was encrypted to is one of the included fingerprints in the signature.
+	// If the flag is disabled, no Intended Recipient Fingerprint sub-packets are created or checked.
+	// The default behavior, when the config or flag is nil, is to enable the feature.
+	CheckIntendedRecipients *bool
+	// CacheSessionKey controls if decryption should return the session key used for decryption.
+	// If the flag is set, the session key is cached in the message details struct.
+	CacheSessionKey bool
+	// CheckPacketSequence is a flag that controls if the pgp message reader should strictly check
+	// that the packet sequence conforms with the grammar mandated by rfc4880.
+	// The default behavior, when the config or flag is nil, is to check the packet sequence.
+	CheckPacketSequence *bool
+	// NonDeterministicSignaturesViaNotation is a flag to enable randomization of signatures.
+	// If true, a salt notation is used to randomize signatures generated by v4 and v5 keys
+	// (v6 signatures are always non-deterministic, by design).
+	// This protects EdDSA signatures from potentially leaking the secret key in case of faults (i.e. bitflips) which, in principle, could occur
+	// during the signing computation. It is added to signatures of any algo for simplicity, and as it may also serve as protection in case of
+	// weaknesses in the hash algo, potentially hindering e.g. some chosen-prefix attacks.
+	// The default behavior, when the config or flag is nil, is to enable the feature.
+	NonDeterministicSignaturesViaNotation *bool
 }
 
 func (c *Config) Random() io.Reader {
@@ -197,7 +260,7 @@ func (c *Config) S2K() *s2k.Config {
 		return nil
 	}
 	// for backwards compatibility
-	if c != nil && c.S2KCount > 0 && c.S2KConfig == nil {
+	if c.S2KCount > 0 && c.S2KConfig == nil {
 		return &s2k.Config{
 			S2KCount: c.S2KCount,
 		}
@@ -233,6 +296,13 @@ func (c *Config) AllowUnauthenticatedMessages() bool {
 	return c.InsecureAllowUnauthenticatedMessages
 }
 
+func (c *Config) AllowDecryptionWithSigningKeys() bool {
+	if c == nil {
+		return false
+	}
+	return c.InsecureAllowDecryptionWithSigningKeys
+}
+
 func (c *Config) KnownNotation(notationName string) bool {
 	if c == nil {
 		return false
@@ -246,3 +316,95 @@ func (c *Config) Notations() []*Notation {
 	}
 	return c.SignatureNotations
 }
+
+func (c *Config) V6() bool {
+	if c == nil {
+		return false
+	}
+	return c.V6Keys
+}
+
+func (c *Config) IntendedRecipients() bool {
+	if c == nil || c.CheckIntendedRecipients == nil {
+		return true
+	}
+	return *c.CheckIntendedRecipients
+}
+
+func (c *Config) RetrieveSessionKey() bool {
+	if c == nil {
+		return false
+	}
+	return c.CacheSessionKey
+}
+
+func (c *Config) MinimumRSABits() uint16 {
+	if c == nil || c.MinRSABits == 0 {
+		return 2047
+	}
+	return c.MinRSABits
+}
+
+func (c *Config) RejectPublicKeyAlgorithm(alg PublicKeyAlgorithm) bool {
+	var rejectedAlgorithms map[PublicKeyAlgorithm]bool
+	if c == nil || c.RejectPublicKeyAlgorithms == nil {
+		// Default
+		rejectedAlgorithms = defaultRejectPublicKeyAlgorithms
+	} else {
+		rejectedAlgorithms = c.RejectPublicKeyAlgorithms
+	}
+	return rejectedAlgorithms[alg]
+}
+
+func (c *Config) RejectHashAlgorithm(hash crypto.Hash) bool {
+	var rejectedAlgorithms map[crypto.Hash]bool
+	if c == nil || c.RejectHashAlgorithms == nil {
+		// Default
+		rejectedAlgorithms = defaultRejectHashAlgorithms
+	} else {
+		rejectedAlgorithms = c.RejectHashAlgorithms
+	}
+	return rejectedAlgorithms[hash]
+}
+
+func (c *Config) RejectMessageHashAlgorithm(hash crypto.Hash) bool {
+	var rejectedAlgorithms map[crypto.Hash]bool
+	if c == nil || c.RejectMessageHashAlgorithms == nil {
+		// Default
+		rejectedAlgorithms = defaultRejectMessageHashAlgorithms
+	} else {
+		rejectedAlgorithms = c.RejectMessageHashAlgorithms
+	}
+	return rejectedAlgorithms[hash]
+}
+
+func (c *Config) RejectCurve(curve Curve) bool {
+	var rejectedCurve map[Curve]bool
+	if c == nil || c.RejectCurves == nil {
+		// Default
+		rejectedCurve = defaultRejectCurves
+	} else {
+		rejectedCurve = c.RejectCurves
+	}
+	return rejectedCurve[curve]
+}
+
+func (c *Config) StrictPacketSequence() bool {
+	if c == nil || c.CheckPacketSequence == nil {
+		return true
+	}
+	return *c.CheckPacketSequence
+}
+
+func (c *Config) RandomizeSignaturesViaNotation() bool {
+	if c == nil || c.NonDeterministicSignaturesViaNotation == nil {
+		return true
+	}
+	return *c.NonDeterministicSignaturesViaNotation
+}
+
+// BoolPointer is a helper function to set a boolean pointer in the Config.
+// e.g., config.CheckPacketSequence = BoolPointer(true)
+func BoolPointer(value bool) *bool {
+	return &value
+}

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/config_v5.go

@@ -0,0 +1,7 @@
+//go:build !v5
+
+package packet
+
+func init() {
+	V5Disabled = true
+}

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/encrypted_key.go

@@ -5,9 +5,11 @@
 package packet
 
 import (
+	"bytes"
 	"crypto"
 	"crypto/rsa"
 	"encoding/binary"
+	"encoding/hex"
 	"io"
 	"math/big"
 	"strconv"
@@ -16,32 +18,85 @@ import (
 	"github.com/ProtonMail/go-crypto/openpgp/elgamal"
 	"github.com/ProtonMail/go-crypto/openpgp/errors"
 	"github.com/ProtonMail/go-crypto/openpgp/internal/encoding"
+	"github.com/ProtonMail/go-crypto/openpgp/x25519"
+	"github.com/ProtonMail/go-crypto/openpgp/x448"
 )
 
-const encryptedKeyVersion = 3
-
 // EncryptedKey represents a public-key encrypted session key. See RFC 4880,
 // section 5.1.
 type EncryptedKey struct {
-	KeyId      uint64
-	Algo       PublicKeyAlgorithm
-	CipherFunc CipherFunction // only valid after a successful Decrypt for a v3 packet
-	Key        []byte         // only valid after a successful Decrypt
+	Version        int
+	KeyId          uint64
+	KeyVersion     int    // v6
+	KeyFingerprint []byte // v6
+	Algo           PublicKeyAlgorithm
+	CipherFunc     CipherFunction // only valid after a successful Decrypt for a v3 packet
+	Key            []byte         // only valid after a successful Decrypt
 
 	encryptedMPI1, encryptedMPI2 encoding.Field
+	ephemeralPublicX25519        *x25519.PublicKey // used for x25519
+	ephemeralPublicX448          *x448.PublicKey   // used for x448
+	encryptedSession             []byte            // used for x25519 and x448
 }
 
 func (e *EncryptedKey) parse(r io.Reader) (err error) {
-	var buf [10]byte
-	_, err = readFull(r, buf[:])
+	var buf [8]byte
+	_, err = readFull(r, buf[:versionSize])
 	if err != nil {
 		return
 	}
-	if buf[0] != encryptedKeyVersion {
+	e.Version = int(buf[0])
+	if e.Version != 3 && e.Version != 6 {
 		return errors.UnsupportedError("unknown EncryptedKey version " + strconv.Itoa(int(buf[0])))
 	}
-	e.KeyId = binary.BigEndian.Uint64(buf[1:9])
-	e.Algo = PublicKeyAlgorithm(buf[9])
+	if e.Version == 6 {
+		//Read a one-octet size of the following two fields.
+		if _, err = readFull(r, buf[:1]); err != nil {
+			return
+		}
+		// The size may also be zero, and the key version and
+		// fingerprint omitted for an "anonymous recipient"
+		if buf[0] != 0 {
+			// non-anonymous case
+			_, err = readFull(r, buf[:versionSize])
+			if err != nil {
+				return
+			}
+			e.KeyVersion = int(buf[0])
+			if e.KeyVersion != 4 && e.KeyVersion != 6 {
+				return errors.UnsupportedError("unknown public key version " + strconv.Itoa(e.KeyVersion))
+			}
+			var fingerprint []byte
+			if e.KeyVersion == 6 {
+				fingerprint = make([]byte, fingerprintSizeV6)
+			} else if e.KeyVersion == 4 {
+				fingerprint = make([]byte, fingerprintSize)
+			}
+			_, err = readFull(r, fingerprint)
+			if err != nil {
+				return
+			}
+			e.KeyFingerprint = fingerprint
+			if e.KeyVersion == 6 {
+				e.KeyId = binary.BigEndian.Uint64(e.KeyFingerprint[:keyIdSize])
+			} else if e.KeyVersion == 4 {
+				e.KeyId = binary.BigEndian.Uint64(e.KeyFingerprint[fingerprintSize-keyIdSize : fingerprintSize])
+			}
+		}
+	} else {
+		_, err = readFull(r, buf[:8])
+		if err != nil {
+			return
+		}
+		e.KeyId = binary.BigEndian.Uint64(buf[:keyIdSize])
+	}
+
+	_, err = readFull(r, buf[:1])
+	if err != nil {
+		return
+	}
+	e.Algo = PublicKeyAlgorithm(buf[0])
+	var cipherFunction byte
 	switch e.Algo {
 	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly:
 		e.encryptedMPI1 = new(encoding.MPI)
@@ -68,26 +123,39 @@ func (e *EncryptedKey) parse(r io.Reader) (err error) {
 		if _, err = e.encryptedMPI2.ReadFrom(r); err != nil {
 			return
 		}
+	case PubKeyAlgoX25519:
+		e.ephemeralPublicX25519, e.encryptedSession, cipherFunction, err = x25519.DecodeFields(r, e.Version == 6)
+		if err != nil {
+			return
+		}
+	case PubKeyAlgoX448:
+		e.ephemeralPublicX448, e.encryptedSession, cipherFunction, err = x448.DecodeFields(r, e.Version == 6)
+		if err != nil {
+			return
+		}
 	}
+	if e.Version < 6 {
+		switch e.Algo {
+		case PubKeyAlgoX25519, PubKeyAlgoX448:
+			e.CipherFunc = CipherFunction(cipherFunction)
+			// Check for validiy is in the Decrypt method
+		}
+	}
+
 	_, err = consumeAll(r)
 	return
 }
 
-func checksumKeyMaterial(key []byte) uint16 {
-	var checksum uint16
-	for _, v := range key {
-		checksum += uint16(v)
-	}
-	return checksum
-}
-
 // Decrypt decrypts an encrypted session key with the given private key. The
 // private key must have been decrypted first.
 // If config is nil, sensible defaults will be used.
 func (e *EncryptedKey) Decrypt(priv *PrivateKey, config *Config) error {
-	if e.KeyId != 0 && e.KeyId != priv.KeyId {
+	if e.Version < 6 && e.KeyId != 0 && e.KeyId != priv.KeyId {
 		return errors.InvalidArgumentError("cannot decrypt encrypted session key for key id " + strconv.FormatUint(e.KeyId, 16) + " with private key id " + strconv.FormatUint(priv.KeyId, 16))
 	}
+	if e.Version == 6 && e.KeyVersion != 0 && !bytes.Equal(e.KeyFingerprint, priv.Fingerprint) {
+		return errors.InvalidArgumentError("cannot decrypt encrypted session key for key fingerprint " + hex.EncodeToString(e.KeyFingerprint) + " with private key fingerprint " + hex.EncodeToString(priv.Fingerprint))
+	}
 	if e.Algo != priv.PubKeyAlgo {
 		return errors.InvalidArgumentError("cannot decrypt encrypted session key of type " + strconv.Itoa(int(e.Algo)) + " with private key of type " + strconv.Itoa(int(priv.PubKeyAlgo)))
 	}
@@ -113,52 +181,116 @@ func (e *EncryptedKey) Decrypt(priv *PrivateKey, config *Config) error {
 		vsG := e.encryptedMPI1.Bytes()
 		m := e.encryptedMPI2.Bytes()
 		oid := priv.PublicKey.oid.EncodedBytes()
-		b, err = ecdh.Decrypt(priv.PrivateKey.(*ecdh.PrivateKey), vsG, m, oid, priv.PublicKey.Fingerprint[:])
+		fp := priv.PublicKey.Fingerprint[:]
+		if priv.PublicKey.Version == 5 {
+			// For v5 the, the fingerprint must be restricted to 20 bytes
+			fp = fp[:20]
+		}
+		b, err = ecdh.Decrypt(priv.PrivateKey.(*ecdh.PrivateKey), vsG, m, oid, fp)
+	case PubKeyAlgoX25519:
+		b, err = x25519.Decrypt(priv.PrivateKey.(*x25519.PrivateKey), e.ephemeralPublicX25519, e.encryptedSession)
+	case PubKeyAlgoX448:
+		b, err = x448.Decrypt(priv.PrivateKey.(*x448.PrivateKey), e.ephemeralPublicX448, e.encryptedSession)
 	default:
 		err = errors.InvalidArgumentError("cannot decrypt encrypted session key with private key of type " + strconv.Itoa(int(priv.PubKeyAlgo)))
 	}
-
 	if err != nil {
 		return err
 	}
 
-	e.CipherFunc = CipherFunction(b[0])
-	if !e.CipherFunc.IsSupported() {
-		return errors.UnsupportedError("unsupported encryption function")
+	var key []byte
+	switch priv.PubKeyAlgo {
+	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoElGamal, PubKeyAlgoECDH:
+		keyOffset := 0
+		if e.Version < 6 {
+			e.CipherFunc = CipherFunction(b[0])
+			keyOffset = 1
+			if !e.CipherFunc.IsSupported() {
+				return errors.UnsupportedError("unsupported encryption function")
+			}
+		}
+		key, err = decodeChecksumKey(b[keyOffset:])
+		if err != nil {
+			return err
+		}
+	case PubKeyAlgoX25519, PubKeyAlgoX448:
+		if e.Version < 6 {
+			switch e.CipherFunc {
+			case CipherAES128, CipherAES192, CipherAES256:
+				break
+			default:
+				return errors.StructuralError("v3 PKESK mandates AES as cipher function for x25519 and x448")
+			}
+		}
+		key = b[:]
+	default:
+		return errors.UnsupportedError("unsupported algorithm for decryption")
 	}
-
-	e.Key = b[1 : len(b)-2]
-	expectedChecksum := uint16(b[len(b)-2])<<8 | uint16(b[len(b)-1])
-	checksum := checksumKeyMaterial(e.Key)
-	if checksum != expectedChecksum {
-		return errors.StructuralError("EncryptedKey checksum incorrect")
-	}
-
+	e.Key = key
 	return nil
 }
 
 // Serialize writes the encrypted key packet, e, to w.
 func (e *EncryptedKey) Serialize(w io.Writer) error {
-	var mpiLen int
+	var encodedLength int
 	switch e.Algo {
 	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly:
-		mpiLen = int(e.encryptedMPI1.EncodedLength())
+		encodedLength = int(e.encryptedMPI1.EncodedLength())
 	case PubKeyAlgoElGamal:
-		mpiLen = int(e.encryptedMPI1.EncodedLength()) + int(e.encryptedMPI2.EncodedLength())
+		encodedLength = int(e.encryptedMPI1.EncodedLength()) + int(e.encryptedMPI2.EncodedLength())
 	case PubKeyAlgoECDH:
-		mpiLen = int(e.encryptedMPI1.EncodedLength()) + int(e.encryptedMPI2.EncodedLength())
+		encodedLength = int(e.encryptedMPI1.EncodedLength()) + int(e.encryptedMPI2.EncodedLength())
+	case PubKeyAlgoX25519:
+		encodedLength = x25519.EncodedFieldsLength(e.encryptedSession, e.Version == 6)
+	case PubKeyAlgoX448:
+		encodedLength = x448.EncodedFieldsLength(e.encryptedSession, e.Version == 6)
 	default:
 		return errors.InvalidArgumentError("don't know how to serialize encrypted key type " + strconv.Itoa(int(e.Algo)))
 	}
 
-	err := serializeHeader(w, packetTypeEncryptedKey, 1 /* version */ +8 /* key id */ +1 /* algo */ +mpiLen)
+	packetLen := versionSize /* version */ + keyIdSize /* key id */ + algorithmSize /* algo */ + encodedLength
+	if e.Version == 6 {
+		packetLen = versionSize /* version */ + algorithmSize /* algo */ + encodedLength + keyVersionSize /* key version */
+		if e.KeyVersion == 6 {
+			packetLen += fingerprintSizeV6
+		} else if e.KeyVersion == 4 {
+			packetLen += fingerprintSize
+		}
+	}
+
+	err := serializeHeader(w, packetTypeEncryptedKey, packetLen)
 	if err != nil {
 		return err
 	}
 
-	w.Write([]byte{encryptedKeyVersion})
-	binary.Write(w, binary.BigEndian, e.KeyId)
-	w.Write([]byte{byte(e.Algo)})
+	_, err = w.Write([]byte{byte(e.Version)})
+	if err != nil {
+		return err
+	}
+	if e.Version == 6 {
+		_, err = w.Write([]byte{byte(e.KeyVersion)})
+		if err != nil {
+			return err
+		}
+		// The key version number may also be zero,
+		// and the fingerprint omitted
+		if e.KeyVersion != 0 {
+			_, err = w.Write(e.KeyFingerprint)
+			if err != nil {
+				return err
+			}
+		}
+	} else {
+		// Write KeyID
+		err = binary.Write(w, binary.BigEndian, e.KeyId)
+		if err != nil {
+			return err
+		}
+	}
+	_, err = w.Write([]byte{byte(e.Algo)})
+	if err != nil {
+		return err
+	}
 
 	switch e.Algo {
 	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly:
@@ -176,34 +308,115 @@ func (e *EncryptedKey) Serialize(w io.Writer) error {
 		}
 		_, err := w.Write(e.encryptedMPI2.EncodedBytes())
 		return err
+	case PubKeyAlgoX25519:
+		err := x25519.EncodeFields(w, e.ephemeralPublicX25519, e.encryptedSession, byte(e.CipherFunc), e.Version == 6)
+		return err
+	case PubKeyAlgoX448:
+		err := x448.EncodeFields(w, e.ephemeralPublicX448, e.encryptedSession, byte(e.CipherFunc), e.Version == 6)
+		return err
 	default:
 		panic("internal error")
 	}
 }
 
-// SerializeEncryptedKey serializes an encrypted key packet to w that contains
+// SerializeEncryptedKeyAEAD serializes an encrypted key packet to w that contains
 // key, encrypted to pub.
+// If aeadSupported is set, PKESK v6 is used, otherwise v3.
+// Note: aeadSupported MUST match the value passed to SerializeSymmetricallyEncrypted.
 // If config is nil, sensible defaults will be used.
-func SerializeEncryptedKey(w io.Writer, pub *PublicKey, cipherFunc CipherFunction, key []byte, config *Config) error {
-	var buf [10]byte
-	buf[0] = encryptedKeyVersion
-	binary.BigEndian.PutUint64(buf[1:9], pub.KeyId)
-	buf[9] = byte(pub.PubKeyAlgo)
+func SerializeEncryptedKeyAEAD(w io.Writer, pub *PublicKey, cipherFunc CipherFunction, aeadSupported bool, key []byte, config *Config) error {
+	return SerializeEncryptedKeyAEADwithHiddenOption(w, pub, cipherFunc, aeadSupported, key, false, config)
+}
 
-	keyBlock := make([]byte, 1 /* cipher type */ +len(key)+2 /* checksum */)
-	keyBlock[0] = byte(cipherFunc)
-	copy(keyBlock[1:], key)
-	checksum := checksumKeyMaterial(key)
-	keyBlock[1+len(key)] = byte(checksum >> 8)
-	keyBlock[1+len(key)+1] = byte(checksum)
+// SerializeEncryptedKeyAEADwithHiddenOption serializes an encrypted key packet to w that contains
+// key, encrypted to pub.
+// Offers the hidden flag option to indicated if the PKESK packet should include a wildcard KeyID.
+// If aeadSupported is set, PKESK v6 is used, otherwise v3.
+// Note: aeadSupported MUST match the value passed to SerializeSymmetricallyEncrypted.
+// If config is nil, sensible defaults will be used.
+func SerializeEncryptedKeyAEADwithHiddenOption(w io.Writer, pub *PublicKey, cipherFunc CipherFunction, aeadSupported bool, key []byte, hidden bool, config *Config) error {
+	var buf [36]byte // max possible header size is v6
+	lenHeaderWritten := versionSize
+	version := 3
+
+	if aeadSupported {
+		version = 6
+	}
+	// An implementation MUST NOT generate ElGamal v6 PKESKs.
+	if version == 6 && pub.PubKeyAlgo == PubKeyAlgoElGamal {
+		return errors.InvalidArgumentError("ElGamal v6 PKESK are not allowed")
+	}
+	// In v3 PKESKs, for x25519 and x448, mandate using AES
+	if version == 3 && (pub.PubKeyAlgo == PubKeyAlgoX25519 || pub.PubKeyAlgo == PubKeyAlgoX448) {
+		switch cipherFunc {
+		case CipherAES128, CipherAES192, CipherAES256:
+			break
+		default:
+			return errors.InvalidArgumentError("v3 PKESK mandates AES for x25519 and x448")
+		}
+	}
+
+	buf[0] = byte(version)
+
+	// If hidden is set, the key should be hidden
+	// An implementation MAY accept or use a Key ID of all zeros,
+	// or a key version of zero and no key fingerprint, to hide the intended decryption key.
+	// See Section 5.1.8. in the open pgp crypto refresh
+	if version == 6 {
+		if !hidden {
+			// A one-octet size of the following two fields.
+			buf[1] = byte(keyVersionSize + len(pub.Fingerprint))
+			// A one octet key version number.
+			buf[2] = byte(pub.Version)
+			lenHeaderWritten += keyVersionSize + 1
+			// The fingerprint of the public key
+			copy(buf[lenHeaderWritten:lenHeaderWritten+len(pub.Fingerprint)], pub.Fingerprint)
+			lenHeaderWritten += len(pub.Fingerprint)
+		} else {
+			// The size may also be zero, and the key version
+			// and fingerprint omitted for an "anonymous recipient"
+			buf[1] = 0
+			lenHeaderWritten += 1
+		}
+	} else {
+		if !hidden {
+			binary.BigEndian.PutUint64(buf[versionSize:(versionSize+keyIdSize)], pub.KeyId)
+		}
+		lenHeaderWritten += keyIdSize
+	}
+	buf[lenHeaderWritten] = byte(pub.PubKeyAlgo)
+	lenHeaderWritten += algorithmSize
+
+	var keyBlock []byte
+	switch pub.PubKeyAlgo {
+	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoElGamal, PubKeyAlgoECDH:
+		lenKeyBlock := len(key) + 2
+		if version < 6 {
+			lenKeyBlock += 1 // cipher type included
+		}
+		keyBlock = make([]byte, lenKeyBlock)
+		keyOffset := 0
+		if version < 6 {
+			keyBlock[0] = byte(cipherFunc)
+			keyOffset = 1
+		}
+		encodeChecksumKey(keyBlock[keyOffset:], key)
+	case PubKeyAlgoX25519, PubKeyAlgoX448:
+		// algorithm is added in plaintext below
+		keyBlock = key
+	}
 
 	switch pub.PubKeyAlgo {
 	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly:
-		return serializeEncryptedKeyRSA(w, config.Random(), buf, pub.PublicKey.(*rsa.PublicKey), keyBlock)
+		return serializeEncryptedKeyRSA(w, config.Random(), buf[:lenHeaderWritten], pub.PublicKey.(*rsa.PublicKey), keyBlock)
 	case PubKeyAlgoElGamal:
-		return serializeEncryptedKeyElGamal(w, config.Random(), buf, pub.PublicKey.(*elgamal.PublicKey), keyBlock)
+		return serializeEncryptedKeyElGamal(w, config.Random(), buf[:lenHeaderWritten], pub.PublicKey.(*elgamal.PublicKey), keyBlock)
 	case PubKeyAlgoECDH:
-		return serializeEncryptedKeyECDH(w, config.Random(), buf, pub.PublicKey.(*ecdh.PublicKey), keyBlock, pub.oid, pub.Fingerprint)
+		return serializeEncryptedKeyECDH(w, config.Random(), buf[:lenHeaderWritten], pub.PublicKey.(*ecdh.PublicKey), keyBlock, pub.oid, pub.Fingerprint)
+	case PubKeyAlgoX25519:
+		return serializeEncryptedKeyX25519(w, config.Random(), buf[:lenHeaderWritten], pub.PublicKey.(*x25519.PublicKey), keyBlock, byte(cipherFunc), version)
+	case PubKeyAlgoX448:
+		return serializeEncryptedKeyX448(w, config.Random(), buf[:lenHeaderWritten], pub.PublicKey.(*x448.PublicKey), keyBlock, byte(cipherFunc), version)
 	case PubKeyAlgoDSA, PubKeyAlgoRSASignOnly:
 		return errors.InvalidArgumentError("cannot encrypt to public key of type " + strconv.Itoa(int(pub.PubKeyAlgo)))
 	}
@@ -211,14 +424,32 @@ func SerializeEncryptedKey(w io.Writer, pub *PublicKey, cipherFunc CipherFunctio
 	return errors.UnsupportedError("encrypting a key to public key of type " + strconv.Itoa(int(pub.PubKeyAlgo)))
 }
 
-func serializeEncryptedKeyRSA(w io.Writer, rand io.Reader, header [10]byte, pub *rsa.PublicKey, keyBlock []byte) error {
+// SerializeEncryptedKey serializes an encrypted key packet to w that contains
+// key, encrypted to pub.
+// PKESKv6 is used if config.AEAD() is not nil.
+// If config is nil, sensible defaults will be used.
+// Deprecated: Use SerializeEncryptedKeyAEAD instead.
+func SerializeEncryptedKey(w io.Writer, pub *PublicKey, cipherFunc CipherFunction, key []byte, config *Config) error {
+	return SerializeEncryptedKeyAEAD(w, pub, cipherFunc, config.AEAD() != nil, key, config)
+}
+
+// SerializeEncryptedKeyWithHiddenOption serializes an encrypted key packet to w that contains
+// key, encrypted to pub. PKESKv6 is used if config.AEAD() is not nil.
+// The hidden option controls if the packet should be anonymous, i.e., omit key metadata.
+// If config is nil, sensible defaults will be used.
+// Deprecated: Use SerializeEncryptedKeyAEADwithHiddenOption instead.
+func SerializeEncryptedKeyWithHiddenOption(w io.Writer, pub *PublicKey, cipherFunc CipherFunction, key []byte, hidden bool, config *Config) error {
+	return SerializeEncryptedKeyAEADwithHiddenOption(w, pub, cipherFunc, config.AEAD() != nil, key, hidden, config)
+}
+
+func serializeEncryptedKeyRSA(w io.Writer, rand io.Reader, header []byte, pub *rsa.PublicKey, keyBlock []byte) error {
 	cipherText, err := rsa.EncryptPKCS1v15(rand, pub, keyBlock)
 	if err != nil {
 		return errors.InvalidArgumentError("RSA encryption failed: " + err.Error())
 	}
 
 	cipherMPI := encoding.NewMPI(cipherText)
-	packetLen := 10 /* header length */ + int(cipherMPI.EncodedLength())
+	packetLen := len(header) /* header length */ + int(cipherMPI.EncodedLength())
 
 	err = serializeHeader(w, packetTypeEncryptedKey, packetLen)
 	if err != nil {
@@ -232,13 +463,13 @@ func serializeEncryptedKeyRSA(w io.Writer, rand io.Reader, header [10]byte, pub
 	return err
 }
 
-func serializeEncryptedKeyElGamal(w io.Writer, rand io.Reader, header [10]byte, pub *elgamal.PublicKey, keyBlock []byte) error {
+func serializeEncryptedKeyElGamal(w io.Writer, rand io.Reader, header []byte, pub *elgamal.PublicKey, keyBlock []byte) error {
 	c1, c2, err := elgamal.Encrypt(rand, pub, keyBlock)
 	if err != nil {
 		return errors.InvalidArgumentError("ElGamal encryption failed: " + err.Error())
 	}
 
-	packetLen := 10 /* header length */
+	packetLen := len(header) /* header length */
 	packetLen += 2 /* mpi size */ + (c1.BitLen()+7)/8
 	packetLen += 2 /* mpi size */ + (c2.BitLen()+7)/8
 
@@ -257,7 +488,7 @@ func serializeEncryptedKeyElGamal(w io.Writer, rand io.Reader, header [10]byte,
 	return err
 }
 
-func serializeEncryptedKeyECDH(w io.Writer, rand io.Reader, header [10]byte, pub *ecdh.PublicKey, keyBlock []byte, oid encoding.Field, fingerprint []byte) error {
+func serializeEncryptedKeyECDH(w io.Writer, rand io.Reader, header []byte, pub *ecdh.PublicKey, keyBlock []byte, oid encoding.Field, fingerprint []byte) error {
 	vsG, c, err := ecdh.Encrypt(rand, pub, keyBlock, oid.EncodedBytes(), fingerprint)
 	if err != nil {
 		return errors.InvalidArgumentError("ECDH encryption failed: " + err.Error())
@@ -266,7 +497,7 @@ func serializeEncryptedKeyECDH(w io.Writer, rand io.Reader, header [10]byte, pub
 	g := encoding.NewMPI(vsG)
 	m := encoding.NewOID(c)
 
-	packetLen := 10 /* header length */
+	packetLen := len(header) /* header length */
 	packetLen += int(g.EncodedLength()) + int(m.EncodedLength())
 
 	err = serializeHeader(w, packetTypeEncryptedKey, packetLen)
@@ -284,3 +515,70 @@ func serializeEncryptedKeyECDH(w io.Writer, rand io.Reader, header [10]byte, pub
 	_, err = w.Write(m.EncodedBytes())
 	return err
 }
+
+func serializeEncryptedKeyX25519(w io.Writer, rand io.Reader, header []byte, pub *x25519.PublicKey, keyBlock []byte, cipherFunc byte, version int) error {
+	ephemeralPublicX25519, ciphertext, err := x25519.Encrypt(rand, pub, keyBlock)
+	if err != nil {
+		return errors.InvalidArgumentError("x25519 encryption failed: " + err.Error())
+	}
+
+	packetLen := len(header) /* header length */
+	packetLen += x25519.EncodedFieldsLength(ciphertext, version == 6)
+
+	err = serializeHeader(w, packetTypeEncryptedKey, packetLen)
+	if err != nil {
+		return err
+	}
+
+	_, err = w.Write(header[:])
+	if err != nil {
+		return err
+	}
+	return x25519.EncodeFields(w, ephemeralPublicX25519, ciphertext, cipherFunc, version == 6)
+}
+
+func serializeEncryptedKeyX448(w io.Writer, rand io.Reader, header []byte, pub *x448.PublicKey, keyBlock []byte, cipherFunc byte, version int) error {
+	ephemeralPublicX448, ciphertext, err := x448.Encrypt(rand, pub, keyBlock)
+	if err != nil {
+		return errors.InvalidArgumentError("x448 encryption failed: " + err.Error())
+	}
+
+	packetLen := len(header) /* header length */
+	packetLen += x448.EncodedFieldsLength(ciphertext, version == 6)
+
+	err = serializeHeader(w, packetTypeEncryptedKey, packetLen)
+	if err != nil {
+		return err
+	}
+
+	_, err = w.Write(header[:])
+	if err != nil {
+		return err
+	}
+	return x448.EncodeFields(w, ephemeralPublicX448, ciphertext, cipherFunc, version == 6)
+}
+
+func checksumKeyMaterial(key []byte) uint16 {
+	var checksum uint16
+	for _, v := range key {
+		checksum += uint16(v)
+	}
+	return checksum
+}
+
+func decodeChecksumKey(msg []byte) (key []byte, err error) {
+	key = msg[:len(msg)-2]
+	expectedChecksum := uint16(msg[len(msg)-2])<<8 | uint16(msg[len(msg)-1])
+	checksum := checksumKeyMaterial(key)
+	if checksum != expectedChecksum {
+		err = errors.StructuralError("session key checksum is incorrect")
+	}
+	return
+}
+
+func encodeChecksumKey(buffer []byte, key []byte) {
+	copy(buffer, key)
+	checksum := checksumKeyMaterial(key)
+	buffer[len(key)] = byte(checksum >> 8)
+	buffer[len(key)+1] = byte(checksum)
+}

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/literal.go

@@ -58,9 +58,9 @@ func (l *LiteralData) parse(r io.Reader) (err error) {
 // on completion. The fileName is truncated to 255 bytes.
 func SerializeLiteral(w io.WriteCloser, isBinary bool, fileName string, time uint32) (plaintext io.WriteCloser, err error) {
 	var buf [4]byte
-	buf[0] = 't'
-	if isBinary {
-		buf[0] = 'b'
+	buf[0] = 'b'
+	if !isBinary {
+		buf[0] = 'u'
 	}
 	if len(fileName) > 255 {
 		fileName = fileName[:255]

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/marker.go

@@ -0,0 +1,33 @@
+package packet
+
+import (
+	"io"
+
+	"github.com/ProtonMail/go-crypto/openpgp/errors"
+)
+
+type Marker struct{}
+
+const markerString = "PGP"
+
+// parse just checks if the packet contains "PGP".
+func (m *Marker) parse(reader io.Reader) error {
+	var buffer [3]byte
+	if _, err := io.ReadFull(reader, buffer[:]); err != nil {
+		return err
+	}
+	if string(buffer[:]) != markerString {
+		return errors.StructuralError("invalid marker packet")
+	}
+	return nil
+}
+
+// SerializeMarker writes a marker packet to writer.
+func SerializeMarker(writer io.Writer) error {
+	err := serializeHeader(writer, packetTypeMarker, len(markerString))
+	if err != nil {
+		return err
+	}
+	_, err = writer.Write([]byte(markerString))
+	return err
+}

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/one_pass_signature.go

@@ -7,34 +7,37 @@ package packet
 import (
 	"crypto"
 	"encoding/binary"
-	"github.com/ProtonMail/go-crypto/openpgp/errors"
-	"github.com/ProtonMail/go-crypto/openpgp/internal/algorithm"
 	"io"
 	"strconv"
+
+	"github.com/ProtonMail/go-crypto/openpgp/errors"
+	"github.com/ProtonMail/go-crypto/openpgp/internal/algorithm"
 )
 
 // OnePassSignature represents a one-pass signature packet. See RFC 4880,
 // section 5.4.
 type OnePassSignature struct {
-	SigType    SignatureType
-	Hash       crypto.Hash
-	PubKeyAlgo PublicKeyAlgorithm
-	KeyId      uint64
-	IsLast     bool
+	Version        int
+	SigType        SignatureType
+	Hash           crypto.Hash
+	PubKeyAlgo     PublicKeyAlgorithm
+	KeyId          uint64
+	IsLast         bool
+	Salt           []byte // v6 only
+	KeyFingerprint []byte // v6 only
 }
 
-const onePassSignatureVersion = 3
-
 func (ops *OnePassSignature) parse(r io.Reader) (err error) {
-	var buf [13]byte
-
-	_, err = readFull(r, buf[:])
+	var buf [8]byte
+	// Read: version | signature type | hash algorithm | public-key algorithm
+	_, err = readFull(r, buf[:4])
 	if err != nil {
 		return
 	}
-	if buf[0] != onePassSignatureVersion {
-		err = errors.UnsupportedError("one-pass-signature packet version " + strconv.Itoa(int(buf[0])))
+	if buf[0] != 3 && buf[0] != 6 {
+		return errors.UnsupportedError("one-pass-signature packet version " + strconv.Itoa(int(buf[0])))
 	}
+	ops.Version = int(buf[0])
 
 	var ok bool
 	ops.Hash, ok = algorithm.HashIdToHashWithSha1(buf[2])
@@ -44,15 +47,69 @@ func (ops *OnePassSignature) parse(r io.Reader) (err error) {
 
 	ops.SigType = SignatureType(buf[1])
 	ops.PubKeyAlgo = PublicKeyAlgorithm(buf[3])
-	ops.KeyId = binary.BigEndian.Uint64(buf[4:12])
-	ops.IsLast = buf[12] != 0
+
+	if ops.Version == 6 {
+		// Only for v6, a variable-length field containing the salt
+		_, err = readFull(r, buf[:1])
+		if err != nil {
+			return
+		}
+		saltLength := int(buf[0])
+		var expectedSaltLength int
+		expectedSaltLength, err = SaltLengthForHash(ops.Hash)
+		if err != nil {
+			return
+		}
+		if saltLength != expectedSaltLength {
+			err = errors.StructuralError("unexpected salt size for the given hash algorithm")
+			return
+		}
+		salt := make([]byte, expectedSaltLength)
+		_, err = readFull(r, salt)
+		if err != nil {
+			return
+		}
+		ops.Salt = salt
+
+		// Only for v6 packets, 32 octets of the fingerprint of the signing key.
+		fingerprint := make([]byte, 32)
+		_, err = readFull(r, fingerprint)
+		if err != nil {
+			return
+		}
+		ops.KeyFingerprint = fingerprint
+		ops.KeyId = binary.BigEndian.Uint64(ops.KeyFingerprint[:8])
+	} else {
+		_, err = readFull(r, buf[:8])
+		if err != nil {
+			return
+		}
+		ops.KeyId = binary.BigEndian.Uint64(buf[:8])
+	}
+
+	_, err = readFull(r, buf[:1])
+	if err != nil {
+		return
+	}
+	ops.IsLast = buf[0] != 0
 	return
 }
 
 // Serialize marshals the given OnePassSignature to w.
 func (ops *OnePassSignature) Serialize(w io.Writer) error {
-	var buf [13]byte
-	buf[0] = onePassSignatureVersion
+	//v3 length 1+1+1+1+8+1 =
+	packetLength := 13
+	if ops.Version == 6 {
+		// v6 length 1+1+1+1+1+len(salt)+32+1 =
+		packetLength = 38 + len(ops.Salt)
+	}
+
+	if err := serializeHeader(w, packetTypeOnePassSignature, packetLength); err != nil {
+		return err
+	}
+
+	var buf [8]byte
+	buf[0] = byte(ops.Version)
 	buf[1] = uint8(ops.SigType)
 	var ok bool
 	buf[2], ok = algorithm.HashToHashIdWithSha1(ops.Hash)
@@ -60,14 +117,41 @@ func (ops *OnePassSignature) Serialize(w io.Writer) error {
 		return errors.UnsupportedError("hash type: " + strconv.Itoa(int(ops.Hash)))
 	}
 	buf[3] = uint8(ops.PubKeyAlgo)
-	binary.BigEndian.PutUint64(buf[4:12], ops.KeyId)
-	if ops.IsLast {
-		buf[12] = 1
-	}
 
-	if err := serializeHeader(w, packetTypeOnePassSignature, len(buf)); err != nil {
+	_, err := w.Write(buf[:4])
+	if err != nil {
 		return err
 	}
-	_, err := w.Write(buf[:])
+
+	if ops.Version == 6 {
+		// write salt for v6 signatures
+		_, err := w.Write([]byte{uint8(len(ops.Salt))})
+		if err != nil {
+			return err
+		}
+		_, err = w.Write(ops.Salt)
+		if err != nil {
+			return err
+		}
+
+		// write fingerprint v6 signatures
+		_, err = w.Write(ops.KeyFingerprint)
+		if err != nil {
+			return err
+		}
+	} else {
+		binary.BigEndian.PutUint64(buf[:8], ops.KeyId)
+		_, err := w.Write(buf[:8])
+		if err != nil {
+			return err
+		}
+	}
+
+	isLast := []byte{byte(0)}
+	if ops.IsLast {
+		isLast[0] = 1
+	}
+
+	_, err = w.Write(isLast)
 	return err
 }

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/opaque.go

@@ -7,7 +7,6 @@ package packet
 import (
 	"bytes"
 	"io"
-	"io/ioutil"
 
 	"github.com/ProtonMail/go-crypto/openpgp/errors"
 )
@@ -26,7 +25,7 @@ type OpaquePacket struct {
 }
 
 func (op *OpaquePacket) parse(r io.Reader) (err error) {
-	op.Contents, err = ioutil.ReadAll(r)
+	op.Contents, err = io.ReadAll(r)
 	return
 }
 

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/packet.go

@@ -311,12 +311,15 @@ const (
 	packetTypePrivateSubkey                            packetType = 7
 	packetTypeCompressed                               packetType = 8
 	packetTypeSymmetricallyEncrypted                   packetType = 9
+	packetTypeMarker                                   packetType = 10
 	packetTypeLiteralData                              packetType = 11
+	packetTypeTrust                                    packetType = 12
 	packetTypeUserId                                   packetType = 13
 	packetTypePublicSubkey                             packetType = 14
 	packetTypeUserAttribute                            packetType = 17
 	packetTypeSymmetricallyEncryptedIntegrityProtected packetType = 18
 	packetTypeAEADEncrypted                            packetType = 20
+	packetPadding                                      packetType = 21
 )
 
 // EncryptedDataPacket holds encrypted data. It is currently implemented by
@@ -328,7 +331,7 @@ type EncryptedDataPacket interface {
 // Read reads a single OpenPGP packet from the given io.Reader. If there is an
 // error parsing a packet, the whole packet is consumed from the input.
 func Read(r io.Reader) (p Packet, err error) {
-	tag, _, contents, err := readHeader(r)
+	tag, len, contents, err := readHeader(r)
 	if err != nil {
 		return
 	}
@@ -367,8 +370,93 @@ func Read(r io.Reader) (p Packet, err error) {
 		p = se
 	case packetTypeAEADEncrypted:
 		p = new(AEADEncrypted)
-	default:
+	case packetPadding:
+		p = Padding(len)
+	case packetTypeMarker:
+		p = new(Marker)
+	case packetTypeTrust:
+		// Not implemented, just consume
 		err = errors.UnknownPacketTypeError(tag)
+	default:
+		// Packet Tags from 0 to 39 are critical.
+		// Packet Tags from 40 to 63 are non-critical.
+		if tag < 40 {
+			err = errors.CriticalUnknownPacketTypeError(tag)
+		} else {
+			err = errors.UnknownPacketTypeError(tag)
+		}
+	}
+	if p != nil {
+		err = p.parse(contents)
+	}
+	if err != nil {
+		consumeAll(contents)
+	}
+	return
+}
+
+// ReadWithCheck reads a single OpenPGP message packet from the given io.Reader. If there is an
+// error parsing a packet, the whole packet is consumed from the input.
+// ReadWithCheck additionally checks if the OpenPGP message packet sequence adheres
+// to the packet composition rules in rfc4880, if not throws an error.
+func ReadWithCheck(r io.Reader, sequence *SequenceVerifier) (p Packet, msgErr error, err error) {
+	tag, len, contents, err := readHeader(r)
+	if err != nil {
+		return
+	}
+	switch tag {
+	case packetTypeEncryptedKey:
+		msgErr = sequence.Next(ESKSymbol)
+		p = new(EncryptedKey)
+	case packetTypeSignature:
+		msgErr = sequence.Next(SigSymbol)
+		p = new(Signature)
+	case packetTypeSymmetricKeyEncrypted:
+		msgErr = sequence.Next(ESKSymbol)
+		p = new(SymmetricKeyEncrypted)
+	case packetTypeOnePassSignature:
+		msgErr = sequence.Next(OPSSymbol)
+		p = new(OnePassSignature)
+	case packetTypeCompressed:
+		msgErr = sequence.Next(CompSymbol)
+		p = new(Compressed)
+	case packetTypeSymmetricallyEncrypted:
+		msgErr = sequence.Next(EncSymbol)
+		p = new(SymmetricallyEncrypted)
+	case packetTypeLiteralData:
+		msgErr = sequence.Next(LDSymbol)
+		p = new(LiteralData)
+	case packetTypeSymmetricallyEncryptedIntegrityProtected:
+		msgErr = sequence.Next(EncSymbol)
+		se := new(SymmetricallyEncrypted)
+		se.IntegrityProtected = true
+		p = se
+	case packetTypeAEADEncrypted:
+		msgErr = sequence.Next(EncSymbol)
+		p = new(AEADEncrypted)
+	case packetPadding:
+		p = Padding(len)
+	case packetTypeMarker:
+		p = new(Marker)
+	case packetTypeTrust:
+		// Not implemented, just consume
+		err = errors.UnknownPacketTypeError(tag)
+	case packetTypePrivateKey,
+		packetTypePrivateSubkey,
+		packetTypePublicKey,
+		packetTypePublicSubkey,
+		packetTypeUserId,
+		packetTypeUserAttribute:
+		msgErr = sequence.Next(UnknownSymbol)
+		consumeAll(contents)
+	default:
+		// Packet Tags from 0 to 39 are critical.
+		// Packet Tags from 40 to 63 are non-critical.
+		if tag < 40 {
+			err = errors.CriticalUnknownPacketTypeError(tag)
+		} else {
+			err = errors.UnknownPacketTypeError(tag)
+		}
 	}
 	if p != nil {
 		err = p.parse(contents)
@@ -385,17 +473,17 @@ type SignatureType uint8
 
 const (
 	SigTypeBinary                  SignatureType = 0x00
-	SigTypeText                                  = 0x01
-	SigTypeGenericCert                           = 0x10
-	SigTypePersonaCert                           = 0x11
-	SigTypeCasualCert                            = 0x12
-	SigTypePositiveCert                          = 0x13
-	SigTypeSubkeyBinding                         = 0x18
-	SigTypePrimaryKeyBinding                     = 0x19
-	SigTypeDirectSignature                       = 0x1F
-	SigTypeKeyRevocation                         = 0x20
-	SigTypeSubkeyRevocation                      = 0x28
-	SigTypeCertificationRevocation               = 0x30
+	SigTypeText                    SignatureType = 0x01
+	SigTypeGenericCert             SignatureType = 0x10
+	SigTypePersonaCert             SignatureType = 0x11
+	SigTypeCasualCert              SignatureType = 0x12
+	SigTypePositiveCert            SignatureType = 0x13
+	SigTypeSubkeyBinding           SignatureType = 0x18
+	SigTypePrimaryKeyBinding       SignatureType = 0x19
+	SigTypeDirectSignature         SignatureType = 0x1F
+	SigTypeKeyRevocation           SignatureType = 0x20
+	SigTypeSubkeyRevocation        SignatureType = 0x28
+	SigTypeCertificationRevocation SignatureType = 0x30
 )
 
 // PublicKeyAlgorithm represents the different public key system specified for
@@ -412,6 +500,11 @@ const (
 	PubKeyAlgoECDSA PublicKeyAlgorithm = 19
 	// https://www.ietf.org/archive/id/draft-koch-eddsa-for-openpgp-04.txt
 	PubKeyAlgoEdDSA PublicKeyAlgorithm = 22
+	// https://datatracker.ietf.org/doc/html/draft-ietf-openpgp-crypto-refresh
+	PubKeyAlgoX25519  PublicKeyAlgorithm = 25
+	PubKeyAlgoX448    PublicKeyAlgorithm = 26
+	PubKeyAlgoEd25519 PublicKeyAlgorithm = 27
+	PubKeyAlgoEd448   PublicKeyAlgorithm = 28
 
 	// Deprecated in RFC 4880, Section 13.5. Use key flags instead.
 	PubKeyAlgoRSAEncryptOnly PublicKeyAlgorithm = 2
@@ -422,7 +515,7 @@ const (
 // key of the given type.
 func (pka PublicKeyAlgorithm) CanEncrypt() bool {
 	switch pka {
-	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoElGamal, PubKeyAlgoECDH:
+	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoElGamal, PubKeyAlgoECDH, PubKeyAlgoX25519, PubKeyAlgoX448:
 		return true
 	}
 	return false
@@ -432,7 +525,7 @@ func (pka PublicKeyAlgorithm) CanEncrypt() bool {
 // sign a message.
 func (pka PublicKeyAlgorithm) CanSign() bool {
 	switch pka {
-	case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly, PubKeyAlgoDSA, PubKeyAlgoECDSA, PubKeyAlgoEdDSA:
+	case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly, PubKeyAlgoDSA, PubKeyAlgoECDSA, PubKeyAlgoEdDSA, PubKeyAlgoEd25519, PubKeyAlgoEd448:
 		return true
 	}
 	return false
@@ -512,6 +605,11 @@ func (mode AEADMode) TagLength() int {
 	return algorithm.AEADMode(mode).TagLength()
 }
 
+// IsSupported returns true if the aead mode is supported from the library
+func (mode AEADMode) IsSupported() bool {
+	return algorithm.AEADMode(mode).TagLength() > 0
+}
+
 // new returns a fresh instance of the given mode.
 func (mode AEADMode) new(block cipher.Block) cipher.AEAD {
 	return algorithm.AEADMode(mode).New(block)
@@ -526,8 +624,17 @@ const (
 	KeySuperseded  ReasonForRevocation = 1
 	KeyCompromised ReasonForRevocation = 2
 	KeyRetired     ReasonForRevocation = 3
+	UserIDNotValid ReasonForRevocation = 32
+	Unknown        ReasonForRevocation = 200
 )
 
+func NewReasonForRevocation(value byte) ReasonForRevocation {
+	if value < 4 || value == 32 {
+		return ReasonForRevocation(value)
+	}
+	return Unknown
+}
+
 // Curve is a mapping to supported ECC curves for key generation.
 // See https://www.ietf.org/archive/id/draft-ietf-openpgp-crypto-refresh-06.html#name-curve-specific-wire-formats
 type Curve string
@@ -549,3 +656,20 @@ type TrustLevel uint8
 
 // TrustAmount represents a trust amount per RFC4880 5.2.3.13
 type TrustAmount uint8
+
+const (
+	// versionSize is the length in bytes of the version value.
+	versionSize = 1
+	// algorithmSize is the length in bytes of the key algorithm value.
+	algorithmSize = 1
+	// keyVersionSize is the length in bytes of the key version value
+	keyVersionSize = 1
+	// keyIdSize is the length in bytes of the key identifier value.
+	keyIdSize = 8
+	// timestampSize is the length in bytes of encoded timestamps.
+	timestampSize = 4
+	// fingerprintSizeV6 is the length in bytes of the key fingerprint in v6.
+	fingerprintSizeV6 = 32
+	// fingerprintSize is the length in bytes of the key fingerprint.
+	fingerprintSize = 20
+)

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/packet_sequence.go

@@ -0,0 +1,222 @@
+package packet
+
+// This file implements the pushdown automata (PDA) from PGPainless (Paul Schaub)
+// to verify pgp packet sequences. See Paul's blogpost for more details:
+// https://blog.jabberhead.tk/2022/10/26/implementing-packet-sequence-validation-using-pushdown-automata/
+import (
+	"fmt"
+
+	"github.com/ProtonMail/go-crypto/openpgp/errors"
+)
+
+func NewErrMalformedMessage(from State, input InputSymbol, stackSymbol StackSymbol) errors.ErrMalformedMessage {
+	return errors.ErrMalformedMessage(fmt.Sprintf("state %d, input symbol %d, stack symbol %d ", from, input, stackSymbol))
+}
+
+// InputSymbol defines the input alphabet of the PDA
+type InputSymbol uint8
+
+const (
+	LDSymbol InputSymbol = iota
+	SigSymbol
+	OPSSymbol
+	CompSymbol
+	ESKSymbol
+	EncSymbol
+	EOSSymbol
+	UnknownSymbol
+)
+
+// StackSymbol defines the stack alphabet of the PDA
+type StackSymbol int8
+
+const (
+	MsgStackSymbol StackSymbol = iota
+	OpsStackSymbol
+	KeyStackSymbol
+	EndStackSymbol
+	EmptyStackSymbol
+)
+
+// State defines the states of the PDA
+type State int8
+
+const (
+	OpenPGPMessage State = iota
+	ESKMessage
+	LiteralMessage
+	CompressedMessage
+	EncryptedMessage
+	ValidMessage
+)
+
+// transition represents a state transition in the PDA
+type transition func(input InputSymbol, stackSymbol StackSymbol) (State, []StackSymbol, bool, error)
+
+// SequenceVerifier is a pushdown automata to verify
+// PGP messages packet sequences according to rfc4880.
+type SequenceVerifier struct {
+	stack []StackSymbol
+	state State
+}
+
+// Next performs a state transition with the given input symbol.
+// If the transition fails a ErrMalformedMessage is returned.
+func (sv *SequenceVerifier) Next(input InputSymbol) error {
+	for {
+		stackSymbol := sv.popStack()
+		transitionFunc := getTransition(sv.state)
+		nextState, newStackSymbols, redo, err := transitionFunc(input, stackSymbol)
+		if err != nil {
+			return err
+		}
+		if redo {
+			sv.pushStack(stackSymbol)
+		}
+		for _, newStackSymbol := range newStackSymbols {
+			sv.pushStack(newStackSymbol)
+		}
+		sv.state = nextState
+		if !redo {
+			break
+		}
+	}
+	return nil
+}
+
+// Valid returns true if RDA is in a valid state.
+func (sv *SequenceVerifier) Valid() bool {
+	return sv.state == ValidMessage && len(sv.stack) == 0
+}
+
+func (sv *SequenceVerifier) AssertValid() error {
+	if !sv.Valid() {
+		return errors.ErrMalformedMessage("invalid message")
+	}
+	return nil
+}
+
+func NewSequenceVerifier() *SequenceVerifier {
+	return &SequenceVerifier{
+		stack: []StackSymbol{EndStackSymbol, MsgStackSymbol},
+		state: OpenPGPMessage,
+	}
+}
+
+func (sv *SequenceVerifier) popStack() StackSymbol {
+	if len(sv.stack) == 0 {
+		return EmptyStackSymbol
+	}
+	elemIndex := len(sv.stack) - 1
+	stackSymbol := sv.stack[elemIndex]
+	sv.stack = sv.stack[:elemIndex]
+	return stackSymbol
+}
+
+func (sv *SequenceVerifier) pushStack(stackSymbol StackSymbol) {
+	sv.stack = append(sv.stack, stackSymbol)
+}
+
+func getTransition(from State) transition {
+	switch from {
+	case OpenPGPMessage:
+		return fromOpenPGPMessage
+	case LiteralMessage:
+		return fromLiteralMessage
+	case CompressedMessage:
+		return fromCompressedMessage
+	case EncryptedMessage:
+		return fromEncryptedMessage
+	case ESKMessage:
+		return fromESKMessage
+	case ValidMessage:
+		return fromValidMessage
+	}
+	return nil
+}
+
+// fromOpenPGPMessage is the transition for the state OpenPGPMessage.
+func fromOpenPGPMessage(input InputSymbol, stackSymbol StackSymbol) (State, []StackSymbol, bool, error) {
+	if stackSymbol != MsgStackSymbol {
+		return 0, nil, false, NewErrMalformedMessage(OpenPGPMessage, input, stackSymbol)
+	}
+	switch input {
+	case LDSymbol:
+		return LiteralMessage, nil, false, nil
+	case SigSymbol:
+		return OpenPGPMessage, []StackSymbol{MsgStackSymbol}, false, nil
+	case OPSSymbol:
+		return OpenPGPMessage, []StackSymbol{OpsStackSymbol, MsgStackSymbol}, false, nil
+	case CompSymbol:
+		return CompressedMessage, nil, false, nil
+	case ESKSymbol:
+		return ESKMessage, []StackSymbol{KeyStackSymbol}, false, nil
+	case EncSymbol:
+		return EncryptedMessage, nil, false, nil
+	}
+	return 0, nil, false, NewErrMalformedMessage(OpenPGPMessage, input, stackSymbol)
+}
+
+// fromESKMessage is the transition for the state ESKMessage.
+func fromESKMessage(input InputSymbol, stackSymbol StackSymbol) (State, []StackSymbol, bool, error) {
+	if stackSymbol != KeyStackSymbol {
+		return 0, nil, false, NewErrMalformedMessage(ESKMessage, input, stackSymbol)
+	}
+	switch input {
+	case ESKSymbol:
+		return ESKMessage, []StackSymbol{KeyStackSymbol}, false, nil
+	case EncSymbol:
+		return EncryptedMessage, nil, false, nil
+	}
+	return 0, nil, false, NewErrMalformedMessage(ESKMessage, input, stackSymbol)
+}
+
+// fromLiteralMessage is the transition for the state LiteralMessage.
+func fromLiteralMessage(input InputSymbol, stackSymbol StackSymbol) (State, []StackSymbol, bool, error) {
+	switch input {
+	case SigSymbol:
+		if stackSymbol == OpsStackSymbol {
+			return LiteralMessage, nil, false, nil
+		}
+	case EOSSymbol:
+		if stackSymbol == EndStackSymbol {
+			return ValidMessage, nil, false, nil
+		}
+	}
+	return 0, nil, false, NewErrMalformedMessage(LiteralMessage, input, stackSymbol)
+}
+
+// fromLiteralMessage is the transition for the state CompressedMessage.
+func fromCompressedMessage(input InputSymbol, stackSymbol StackSymbol) (State, []StackSymbol, bool, error) {
+	switch input {
+	case SigSymbol:
+		if stackSymbol == OpsStackSymbol {
+			return CompressedMessage, nil, false, nil
+		}
+	case EOSSymbol:
+		if stackSymbol == EndStackSymbol {
+			return ValidMessage, nil, false, nil
+		}
+	}
+	return OpenPGPMessage, []StackSymbol{MsgStackSymbol}, true, nil
+}
+
+// fromEncryptedMessage is the transition for the state EncryptedMessage.
+func fromEncryptedMessage(input InputSymbol, stackSymbol StackSymbol) (State, []StackSymbol, bool, error) {
+	switch input {
+	case SigSymbol:
+		if stackSymbol == OpsStackSymbol {
+			return EncryptedMessage, nil, false, nil
+		}
+	case EOSSymbol:
+		if stackSymbol == EndStackSymbol {
+			return ValidMessage, nil, false, nil
+		}
+	}
+	return OpenPGPMessage, []StackSymbol{MsgStackSymbol}, true, nil
+}
+
+// fromValidMessage is the transition for the state ValidMessage.
+func fromValidMessage(input InputSymbol, stackSymbol StackSymbol) (State, []StackSymbol, bool, error) {
+	return 0, nil, false, NewErrMalformedMessage(ValidMessage, input, stackSymbol)
+}

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/packet_unsupported.go

@@ -0,0 +1,24 @@
+package packet
+
+import (
+	"io"
+
+	"github.com/ProtonMail/go-crypto/openpgp/errors"
+)
+
+// UnsupportedPackage represents a OpenPGP packet with a known packet type
+// but with unsupported content.
+type UnsupportedPacket struct {
+	IncompletePacket Packet
+	Error            errors.UnsupportedError
+}
+
+// Implements the Packet interface
+func (up *UnsupportedPacket) parse(read io.Reader) error {
+	err := up.IncompletePacket.parse(read)
+	if castedErr, ok := err.(errors.UnsupportedError); ok {
+		up.Error = castedErr
+		return nil
+	}
+	return err
+}

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/padding.go

@@ -0,0 +1,26 @@
+package packet
+
+import (
+	"io"
+)
+
+// Padding type represents a Padding Packet (Tag 21).
+// The padding type is represented by the length of its padding.
+// see https://datatracker.ietf.org/doc/html/draft-ietf-openpgp-crypto-refresh#name-padding-packet-tag-21
+type Padding int
+
+// parse just ignores the padding content.
+func (pad Padding) parse(reader io.Reader) error {
+	_, err := io.CopyN(io.Discard, reader, int64(pad))
+	return err
+}
+
+// SerializePadding writes the padding to writer.
+func (pad Padding) SerializePadding(writer io.Writer, rand io.Reader) error {
+	err := serializeHeader(writer, packetPadding, int(pad))
+	if err != nil {
+		return err
+	}
+	_, err = io.CopyN(writer, rand, int64(pad))
+	return err
+}

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/private_key.go

@@ -9,22 +9,28 @@ import (
 	"crypto"
 	"crypto/cipher"
 	"crypto/dsa"
-	"crypto/rand"
 	"crypto/rsa"
 	"crypto/sha1"
+	"crypto/sha256"
+	"crypto/subtle"
+	"fmt"
 	"io"
-	"io/ioutil"
 	"math/big"
 	"strconv"
 	"time"
 
 	"github.com/ProtonMail/go-crypto/openpgp/ecdh"
 	"github.com/ProtonMail/go-crypto/openpgp/ecdsa"
+	"github.com/ProtonMail/go-crypto/openpgp/ed25519"
+	"github.com/ProtonMail/go-crypto/openpgp/ed448"
 	"github.com/ProtonMail/go-crypto/openpgp/eddsa"
 	"github.com/ProtonMail/go-crypto/openpgp/elgamal"
 	"github.com/ProtonMail/go-crypto/openpgp/errors"
 	"github.com/ProtonMail/go-crypto/openpgp/internal/encoding"
 	"github.com/ProtonMail/go-crypto/openpgp/s2k"
+	"github.com/ProtonMail/go-crypto/openpgp/x25519"
+	"github.com/ProtonMail/go-crypto/openpgp/x448"
+	"golang.org/x/crypto/hkdf"
 )
 
 // PrivateKey represents a possibly encrypted private key. See RFC 4880,
@@ -35,14 +41,14 @@ type PrivateKey struct {
 	encryptedData []byte
 	cipher        CipherFunction
 	s2k           func(out, in []byte)
-	// An *{rsa|dsa|elgamal|ecdh|ecdsa|ed25519}.PrivateKey or
+	aead          AEADMode // only relevant if S2KAEAD is enabled
+	// An *{rsa|dsa|elgamal|ecdh|ecdsa|ed25519|ed448}.PrivateKey or
 	// crypto.Signer/crypto.Decrypter (Decryptor RSA only).
-	PrivateKey   interface{}
-	sha1Checksum bool
-	iv           []byte
+	PrivateKey interface{}
+	iv         []byte
 
 	// Type of encryption of the S2K packet
-	// Allowed values are 0 (Not encrypted), 254 (SHA1), or
+	// Allowed values are 0 (Not encrypted), 253 (AEAD), 254 (SHA1), or
 	// 255 (2-byte checksum)
 	s2kType S2KType
 	// Full parameters of the S2K packet
@@ -55,6 +61,8 @@ type S2KType uint8
 const (
 	// S2KNON unencrypt
 	S2KNON S2KType = 0
+	// S2KAEAD use authenticated encryption
+	S2KAEAD S2KType = 253
 	// S2KSHA1 sha1 sum check
 	S2KSHA1 S2KType = 254
 	// S2KCHECKSUM sum check
@@ -103,6 +111,34 @@ func NewECDHPrivateKey(creationTime time.Time, priv *ecdh.PrivateKey) *PrivateKe
 	return pk
 }
 
+func NewX25519PrivateKey(creationTime time.Time, priv *x25519.PrivateKey) *PrivateKey {
+	pk := new(PrivateKey)
+	pk.PublicKey = *NewX25519PublicKey(creationTime, &priv.PublicKey)
+	pk.PrivateKey = priv
+	return pk
+}
+
+func NewX448PrivateKey(creationTime time.Time, priv *x448.PrivateKey) *PrivateKey {
+	pk := new(PrivateKey)
+	pk.PublicKey = *NewX448PublicKey(creationTime, &priv.PublicKey)
+	pk.PrivateKey = priv
+	return pk
+}
+
+func NewEd25519PrivateKey(creationTime time.Time, priv *ed25519.PrivateKey) *PrivateKey {
+	pk := new(PrivateKey)
+	pk.PublicKey = *NewEd25519PublicKey(creationTime, &priv.PublicKey)
+	pk.PrivateKey = priv
+	return pk
+}
+
+func NewEd448PrivateKey(creationTime time.Time, priv *ed448.PrivateKey) *PrivateKey {
+	pk := new(PrivateKey)
+	pk.PublicKey = *NewEd448PublicKey(creationTime, &priv.PublicKey)
+	pk.PrivateKey = priv
+	return pk
+}
+
 // NewSignerPrivateKey creates a PrivateKey from a crypto.Signer that
 // implements RSA, ECDSA or EdDSA.
 func NewSignerPrivateKey(creationTime time.Time, signer interface{}) *PrivateKey {
@@ -122,6 +158,14 @@ func NewSignerPrivateKey(creationTime time.Time, signer interface{}) *PrivateKey
 		pk.PublicKey = *NewEdDSAPublicKey(creationTime, &pubkey.PublicKey)
 	case eddsa.PrivateKey:
 		pk.PublicKey = *NewEdDSAPublicKey(creationTime, &pubkey.PublicKey)
+	case *ed25519.PrivateKey:
+		pk.PublicKey = *NewEd25519PublicKey(creationTime, &pubkey.PublicKey)
+	case ed25519.PrivateKey:
+		pk.PublicKey = *NewEd25519PublicKey(creationTime, &pubkey.PublicKey)
+	case *ed448.PrivateKey:
+		pk.PublicKey = *NewEd448PublicKey(creationTime, &pubkey.PublicKey)
+	case ed448.PrivateKey:
+		pk.PublicKey = *NewEd448PublicKey(creationTime, &pubkey.PublicKey)
 	default:
 		panic("openpgp: unknown signer type in NewSignerPrivateKey")
 	}
@@ -129,7 +173,7 @@ func NewSignerPrivateKey(creationTime time.Time, signer interface{}) *PrivateKey
 	return pk
 }
 
-// NewDecrypterPrivateKey creates a PrivateKey from a *{rsa|elgamal|ecdh}.PrivateKey.
+// NewDecrypterPrivateKey creates a PrivateKey from a *{rsa|elgamal|ecdh|x25519|x448}.PrivateKey.
 func NewDecrypterPrivateKey(creationTime time.Time, decrypter interface{}) *PrivateKey {
 	pk := new(PrivateKey)
 	switch priv := decrypter.(type) {
@@ -139,6 +183,10 @@ func NewDecrypterPrivateKey(creationTime time.Time, decrypter interface{}) *Priv
 		pk.PublicKey = *NewElGamalPublicKey(creationTime, &priv.PublicKey)
 	case *ecdh.PrivateKey:
 		pk.PublicKey = *NewECDHPublicKey(creationTime, &priv.PublicKey)
+	case *x25519.PrivateKey:
+		pk.PublicKey = *NewX25519PublicKey(creationTime, &priv.PublicKey)
+	case *x448.PrivateKey:
+		pk.PublicKey = *NewX448PublicKey(creationTime, &priv.PublicKey)
 	default:
 		panic("openpgp: unknown decrypter type in NewDecrypterPrivateKey")
 	}
@@ -152,6 +200,11 @@ func (pk *PrivateKey) parse(r io.Reader) (err error) {
 		return
 	}
 	v5 := pk.PublicKey.Version == 5
+	v6 := pk.PublicKey.Version == 6
+
+	if V5Disabled && v5 {
+		return errors.UnsupportedError("support for parsing v5 entities is disabled; build with `-tags v5` if needed")
+	}
 
 	var buf [1]byte
 	_, err = readFull(r, buf[:])
@@ -160,7 +213,7 @@ func (pk *PrivateKey) parse(r io.Reader) (err error) {
 	}
 	pk.s2kType = S2KType(buf[0])
 	var optCount [1]byte
-	if v5 {
+	if v5 || (v6 && pk.s2kType != S2KNON) {
 		if _, err = readFull(r, optCount[:]); err != nil {
 			return
 		}
@@ -170,9 +223,9 @@ func (pk *PrivateKey) parse(r io.Reader) (err error) {
 	case S2KNON:
 		pk.s2k = nil
 		pk.Encrypted = false
-	case S2KSHA1, S2KCHECKSUM:
-		if v5 && pk.s2kType == S2KCHECKSUM {
-			return errors.StructuralError("wrong s2k identifier for version 5")
+	case S2KSHA1, S2KCHECKSUM, S2KAEAD:
+		if (v5 || v6) && pk.s2kType == S2KCHECKSUM {
+			return errors.StructuralError(fmt.Sprintf("wrong s2k identifier for version %d", pk.Version))
 		}
 		_, err = readFull(r, buf[:])
 		if err != nil {
@@ -182,6 +235,29 @@ func (pk *PrivateKey) parse(r io.Reader) (err error) {
 		if pk.cipher != 0 && !pk.cipher.IsSupported() {
 			return errors.UnsupportedError("unsupported cipher function in private key")
 		}
+		// [Optional] If string-to-key usage octet was 253,
+		// a one-octet AEAD algorithm.
+		if pk.s2kType == S2KAEAD {
+			_, err = readFull(r, buf[:])
+			if err != nil {
+				return
+			}
+			pk.aead = AEADMode(buf[0])
+			if !pk.aead.IsSupported() {
+				return errors.UnsupportedError("unsupported aead mode in private key")
+			}
+		}
+
+		// [Optional] Only for a version 6 packet,
+		// and if string-to-key usage octet was 255, 254, or 253,
+		// an one-octet count of the following field.
+		if v6 {
+			_, err = readFull(r, buf[:])
+			if err != nil {
+				return
+			}
+		}
+
 		pk.s2kParams, err = s2k.ParseIntoParams(r)
 		if err != nil {
 			return
@@ -189,28 +265,43 @@ func (pk *PrivateKey) parse(r io.Reader) (err error) {
 		if pk.s2kParams.Dummy() {
 			return
 		}
+		if pk.s2kParams.Mode() == s2k.Argon2S2K && pk.s2kType != S2KAEAD {
+			return errors.StructuralError("using Argon2 S2K without AEAD is not allowed")
+		}
+		if pk.s2kParams.Mode() == s2k.SimpleS2K && pk.Version == 6 {
+			return errors.StructuralError("using Simple S2K with version 6 keys is not allowed")
+		}
 		pk.s2k, err = pk.s2kParams.Function()
 		if err != nil {
 			return
 		}
 		pk.Encrypted = true
-		if pk.s2kType == S2KSHA1 {
-			pk.sha1Checksum = true
-		}
 	default:
 		return errors.UnsupportedError("deprecated s2k function in private key")
 	}
 
 	if pk.Encrypted {
-		blockSize := pk.cipher.blockSize()
-		if blockSize == 0 {
+		var ivSize int
+		// If the S2K usage octet was 253, the IV is of the size expected by the AEAD mode,
+		// unless it's a version 5 key, in which case it's the size of the symmetric cipher's block size.
+		// For all other S2K modes, it's always the block size.
+		if !v5 && pk.s2kType == S2KAEAD {
+			ivSize = pk.aead.IvLength()
+		} else {
+			ivSize = pk.cipher.blockSize()
+		}
+
+		if ivSize == 0 {
 			return errors.UnsupportedError("unsupported cipher in private key: " + strconv.Itoa(int(pk.cipher)))
 		}
-		pk.iv = make([]byte, blockSize)
+		pk.iv = make([]byte, ivSize)
 		_, err = readFull(r, pk.iv)
 		if err != nil {
 			return
 		}
+		if v5 && pk.s2kType == S2KAEAD {
+			pk.iv = pk.iv[:pk.aead.IvLength()]
+		}
 	}
 
 	var privateKeyData []byte
@@ -230,7 +321,7 @@ func (pk *PrivateKey) parse(r io.Reader) (err error) {
 			return
 		}
 	} else {
-		privateKeyData, err = ioutil.ReadAll(r)
+		privateKeyData, err = io.ReadAll(r)
 		if err != nil {
 			return
 		}
@@ -239,16 +330,22 @@ func (pk *PrivateKey) parse(r io.Reader) (err error) {
 		if len(privateKeyData) < 2 {
 			return errors.StructuralError("truncated private key data")
 		}
-		var sum uint16
-		for i := 0; i < len(privateKeyData)-2; i++ {
-			sum += uint16(privateKeyData[i])
+		if pk.Version != 6 {
+			// checksum
+			var sum uint16
+			for i := 0; i < len(privateKeyData)-2; i++ {
+				sum += uint16(privateKeyData[i])
+			}
+			if privateKeyData[len(privateKeyData)-2] != uint8(sum>>8) ||
+				privateKeyData[len(privateKeyData)-1] != uint8(sum) {
+				return errors.StructuralError("private key checksum failure")
+			}
+			privateKeyData = privateKeyData[:len(privateKeyData)-2]
+			return pk.parsePrivateKey(privateKeyData)
+		} else {
+			// No checksum
+			return pk.parsePrivateKey(privateKeyData)
 		}
-		if privateKeyData[len(privateKeyData)-2] != uint8(sum>>8) ||
-			privateKeyData[len(privateKeyData)-1] != uint8(sum) {
-			return errors.StructuralError("private key checksum failure")
-		}
-		privateKeyData = privateKeyData[:len(privateKeyData)-2]
-		return pk.parsePrivateKey(privateKeyData)
 	}
 
 	pk.encryptedData = privateKeyData
@@ -280,18 +377,59 @@ func (pk *PrivateKey) Serialize(w io.Writer) (err error) {
 
 	optional := bytes.NewBuffer(nil)
 	if pk.Encrypted || pk.Dummy() {
-		optional.Write([]byte{uint8(pk.cipher)})
-		if err := pk.s2kParams.Serialize(optional); err != nil {
+		// [Optional] If string-to-key usage octet was 255, 254, or 253,
+		// a one-octet symmetric encryption algorithm.
+		if _, err = optional.Write([]byte{uint8(pk.cipher)}); err != nil {
+			return
+		}
+		// [Optional] If string-to-key usage octet was 253,
+		// a one-octet AEAD algorithm.
+		if pk.s2kType == S2KAEAD {
+			if _, err = optional.Write([]byte{uint8(pk.aead)}); err != nil {
+				return
+			}
+		}
+
+		s2kBuffer := bytes.NewBuffer(nil)
+		if err := pk.s2kParams.Serialize(s2kBuffer); err != nil {
 			return err
 		}
+		// [Optional] Only for a version 6 packet, and if string-to-key
+		// usage octet was 255, 254, or 253, an one-octet
+		// count of the following field.
+		if pk.Version == 6 {
+			if _, err = optional.Write([]byte{uint8(s2kBuffer.Len())}); err != nil {
+				return
+			}
+		}
+		// [Optional] If string-to-key usage octet was 255, 254, or 253,
+		// a string-to-key (S2K) specifier. The length of the string-to-key specifier
+		// depends on its type
+		if _, err = io.Copy(optional, s2kBuffer); err != nil {
+			return
+		}
+
+		// IV
 		if pk.Encrypted {
-			optional.Write(pk.iv)
+			if _, err = optional.Write(pk.iv); err != nil {
+				return
+			}
+			if pk.Version == 5 && pk.s2kType == S2KAEAD {
+				// Add padding for version 5
+				padding := make([]byte, pk.cipher.blockSize()-len(pk.iv))
+				if _, err = optional.Write(padding); err != nil {
+					return
+				}
+			}
 		}
 	}
-	if pk.Version == 5 {
+	if pk.Version == 5 || (pk.Version == 6 && pk.s2kType != S2KNON) {
 		contents.Write([]byte{uint8(optional.Len())})
 	}
-	io.Copy(contents, optional)
+
+	if _, err := io.Copy(contents, optional); err != nil {
+		return err
+	}
 
 	if !pk.Dummy() {
 		l := 0
@@ -303,8 +441,10 @@ func (pk *PrivateKey) Serialize(w io.Writer) (err error) {
 				return err
 			}
 			l = buf.Len()
-			checksum := mod64kHash(buf.Bytes())
-			buf.Write([]byte{byte(checksum >> 8), byte(checksum)})
+			if pk.Version != 6 {
+				checksum := mod64kHash(buf.Bytes())
+				buf.Write([]byte{byte(checksum >> 8), byte(checksum)})
+			}
 			priv = buf.Bytes()
 		} else {
 			priv, l = pk.encryptedData, len(pk.encryptedData)
@@ -370,6 +510,26 @@ func serializeECDHPrivateKey(w io.Writer, priv *ecdh.PrivateKey) error {
 	return err
 }
 
+func serializeX25519PrivateKey(w io.Writer, priv *x25519.PrivateKey) error {
+	_, err := w.Write(priv.Secret)
+	return err
+}
+
+func serializeX448PrivateKey(w io.Writer, priv *x448.PrivateKey) error {
+	_, err := w.Write(priv.Secret)
+	return err
+}
+
+func serializeEd25519PrivateKey(w io.Writer, priv *ed25519.PrivateKey) error {
+	_, err := w.Write(priv.MarshalByteSecret())
+	return err
+}
+
+func serializeEd448PrivateKey(w io.Writer, priv *ed448.PrivateKey) error {
+	_, err := w.Write(priv.MarshalByteSecret())
+	return err
+}
+
 // decrypt decrypts an encrypted private key using a decryption key.
 func (pk *PrivateKey) decrypt(decryptionKey []byte) error {
 	if pk.Dummy() {
@@ -378,37 +538,51 @@ func (pk *PrivateKey) decrypt(decryptionKey []byte) error {
 	if !pk.Encrypted {
 		return nil
 	}
-
 	block := pk.cipher.new(decryptionKey)
-	cfb := cipher.NewCFBDecrypter(block, pk.iv)
-
-	data := make([]byte, len(pk.encryptedData))
-	cfb.XORKeyStream(data, pk.encryptedData)
-
-	if pk.sha1Checksum {
-		if len(data) < sha1.Size {
-			return errors.StructuralError("truncated private key data")
+	var data []byte
+	switch pk.s2kType {
+	case S2KAEAD:
+		aead := pk.aead.new(block)
+		additionalData, err := pk.additionalData()
+		if err != nil {
+			return err
 		}
-		h := sha1.New()
-		h.Write(data[:len(data)-sha1.Size])
-		sum := h.Sum(nil)
-		if !bytes.Equal(sum, data[len(data)-sha1.Size:]) {
-			return errors.StructuralError("private key checksum failure")
+		// Decrypt the encrypted key material with aead
+		data, err = aead.Open(nil, pk.iv, pk.encryptedData, additionalData)
+		if err != nil {
+			return err
 		}
-		data = data[:len(data)-sha1.Size]
-	} else {
-		if len(data) < 2 {
-			return errors.StructuralError("truncated private key data")
+	case S2KSHA1, S2KCHECKSUM:
+		cfb := cipher.NewCFBDecrypter(block, pk.iv)
+		data = make([]byte, len(pk.encryptedData))
+		cfb.XORKeyStream(data, pk.encryptedData)
+		if pk.s2kType == S2KSHA1 {
+			if len(data) < sha1.Size {
+				return errors.StructuralError("truncated private key data")
+			}
+			h := sha1.New()
+			h.Write(data[:len(data)-sha1.Size])
+			sum := h.Sum(nil)
+			if !bytes.Equal(sum, data[len(data)-sha1.Size:]) {
+				return errors.StructuralError("private key checksum failure")
+			}
+			data = data[:len(data)-sha1.Size]
+		} else {
+			if len(data) < 2 {
+				return errors.StructuralError("truncated private key data")
+			}
+			var sum uint16
+			for i := 0; i < len(data)-2; i++ {
+				sum += uint16(data[i])
+			}
+			if data[len(data)-2] != uint8(sum>>8) ||
+				data[len(data)-1] != uint8(sum) {
+				return errors.StructuralError("private key checksum failure")
+			}
+			data = data[:len(data)-2]
 		}
-		var sum uint16
-		for i := 0; i < len(data)-2; i++ {
-			sum += uint16(data[i])
-		}
-		if data[len(data)-2] != uint8(sum>>8) ||
-			data[len(data)-1] != uint8(sum) {
-			return errors.StructuralError("private key checksum failure")
-		}
-		data = data[:len(data)-2]
+	default:
+		return errors.InvalidArgumentError("invalid s2k type")
 	}
 
 	err := pk.parsePrivateKey(data)
@@ -424,7 +598,6 @@ func (pk *PrivateKey) decrypt(decryptionKey []byte) error {
 	pk.s2k = nil
 	pk.Encrypted = false
 	pk.encryptedData = nil
-
 	return nil
 }
 
@@ -440,6 +613,9 @@ func (pk *PrivateKey) decryptWithCache(passphrase []byte, keyCache *s2k.Cache) e
 	if err != nil {
 		return err
 	}
+	if pk.s2kType == S2KAEAD {
+		key = pk.applyHKDF(key)
+	}
 	return pk.decrypt(key)
 }
 
@@ -454,11 +630,14 @@ func (pk *PrivateKey) Decrypt(passphrase []byte) error {
 
 	key := make([]byte, pk.cipher.KeySize())
 	pk.s2k(key, passphrase)
+	if pk.s2kType == S2KAEAD {
+		key = pk.applyHKDF(key)
+	}
 	return pk.decrypt(key)
 }
 
 // DecryptPrivateKeys decrypts all encrypted keys with the given config and passphrase.
-// Avoids recomputation of similar s2k key derivations. 
+// Avoids recomputation of similar s2k key derivations.
 func DecryptPrivateKeys(keys []*PrivateKey, passphrase []byte) error {
 	// Create a cache to avoid recomputation of key derviations for the same passphrase.
 	s2kCache := &s2k.Cache{}
@@ -474,7 +653,7 @@ func DecryptPrivateKeys(keys []*PrivateKey, passphrase []byte) error {
 }
 
 // encrypt encrypts an unencrypted private key.
-func (pk *PrivateKey) encrypt(key []byte, params *s2k.Params, cipherFunction CipherFunction) error {
+func (pk *PrivateKey) encrypt(key []byte, params *s2k.Params, s2kType S2KType, cipherFunction CipherFunction, rand io.Reader) error {
 	if pk.Dummy() {
 		return errors.ErrDummyPrivateKey("dummy key found")
 	}
@@ -485,7 +664,15 @@ func (pk *PrivateKey) encrypt(key []byte, params *s2k.Params, cipherFunction Cip
 	if len(key) != cipherFunction.KeySize() {
 		return errors.InvalidArgumentError("supplied encryption key has the wrong size")
 	}
-	
+
+	if params.Mode() == s2k.Argon2S2K && s2kType != S2KAEAD {
+		return errors.InvalidArgumentError("using Argon2 S2K without AEAD is not allowed")
+	}
+	if params.Mode() != s2k.Argon2S2K && params.Mode() != s2k.IteratedSaltedS2K &&
+		params.Mode() != s2k.SaltedS2K { // only allowed for high-entropy passphrases
+		return errors.InvalidArgumentError("insecure S2K mode")
+	}
+
 	priv := bytes.NewBuffer(nil)
 	err := pk.serializePrivateKey(priv)
 	if err != nil {
@@ -497,35 +684,53 @@ func (pk *PrivateKey) encrypt(key []byte, params *s2k.Params, cipherFunction Cip
 	pk.s2k, err = pk.s2kParams.Function()
 	if err != nil {
 		return err
-	} 
+	}
 
 	privateKeyBytes := priv.Bytes()
-	pk.sha1Checksum = true
+	pk.s2kType = s2kType
 	block := pk.cipher.new(key)
-	pk.iv = make([]byte, pk.cipher.blockSize())
-	_, err = rand.Read(pk.iv)
-	if err != nil {
-		return err
-	}
-	cfb := cipher.NewCFBEncrypter(block, pk.iv)
-
-	if pk.sha1Checksum {
-		pk.s2kType = S2KSHA1
-		h := sha1.New()
-		h.Write(privateKeyBytes)
-		sum := h.Sum(nil)
-		privateKeyBytes = append(privateKeyBytes, sum...)
-	} else {
-		pk.s2kType = S2KCHECKSUM
-		var sum uint16
-		for _, b := range privateKeyBytes {
-			sum += uint16(b)
+	switch s2kType {
+	case S2KAEAD:
+		if pk.aead == 0 {
+			return errors.StructuralError("aead mode is not set on key")
 		}
-		priv.Write([]byte{uint8(sum >> 8), uint8(sum)})
+		aead := pk.aead.new(block)
+		additionalData, err := pk.additionalData()
+		if err != nil {
+			return err
+		}
+		pk.iv = make([]byte, aead.NonceSize())
+		_, err = io.ReadFull(rand, pk.iv)
+		if err != nil {
+			return err
+		}
+		// Decrypt the encrypted key material with aead
+		pk.encryptedData = aead.Seal(nil, pk.iv, privateKeyBytes, additionalData)
+	case S2KSHA1, S2KCHECKSUM:
+		pk.iv = make([]byte, pk.cipher.blockSize())
+		_, err = io.ReadFull(rand, pk.iv)
+		if err != nil {
+			return err
+		}
+		cfb := cipher.NewCFBEncrypter(block, pk.iv)
+		if s2kType == S2KSHA1 {
+			h := sha1.New()
+			h.Write(privateKeyBytes)
+			sum := h.Sum(nil)
+			privateKeyBytes = append(privateKeyBytes, sum...)
+		} else {
+			var sum uint16
+			for _, b := range privateKeyBytes {
+				sum += uint16(b)
+			}
+			privateKeyBytes = append(privateKeyBytes, []byte{uint8(sum >> 8), uint8(sum)}...)
+		}
+		pk.encryptedData = make([]byte, len(privateKeyBytes))
+		cfb.XORKeyStream(pk.encryptedData, privateKeyBytes)
+	default:
+		return errors.InvalidArgumentError("invalid s2k type for encryption")
 	}
 
-	pk.encryptedData = make([]byte, len(privateKeyBytes))
-	cfb.XORKeyStream(pk.encryptedData, privateKeyBytes)
 	pk.Encrypted = true
 	pk.PrivateKey = nil
 	return err
@@ -544,8 +749,15 @@ func (pk *PrivateKey) EncryptWithConfig(passphrase []byte, config *Config) error
 		return err
 	}
 	s2k(key, passphrase)
+	s2kType := S2KSHA1
+	if config.AEAD() != nil {
+		s2kType = S2KAEAD
+		pk.aead = config.AEAD().Mode()
+		pk.cipher = config.Cipher()
+		key = pk.applyHKDF(key)
+	}
 	// Encrypt the private key with the derived encryption key.
-	return pk.encrypt(key, params, config.Cipher())
+	return pk.encrypt(key, params, s2kType, config.Cipher(), config.Random())
 }
 
 // EncryptPrivateKeys encrypts all unencrypted keys with the given config and passphrase.
@@ -564,7 +776,16 @@ func EncryptPrivateKeys(keys []*PrivateKey, passphrase []byte, config *Config) e
 	s2k(encryptionKey, passphrase)
 	for _, key := range keys {
 		if key != nil && !key.Dummy() && !key.Encrypted {
-			err = key.encrypt(encryptionKey, params, config.Cipher())
+			s2kType := S2KSHA1
+			if config.AEAD() != nil {
+				s2kType = S2KAEAD
+				key.aead = config.AEAD().Mode()
+				key.cipher = config.Cipher()
+				derivedKey := key.applyHKDF(encryptionKey)
+				err = key.encrypt(derivedKey, params, s2kType, config.Cipher(), config.Random())
+			} else {
+				err = key.encrypt(encryptionKey, params, s2kType, config.Cipher(), config.Random())
+			}
 			if err != nil {
 				return err
 			}
@@ -581,7 +802,7 @@ func (pk *PrivateKey) Encrypt(passphrase []byte) error {
 			S2KMode:  s2k.IteratedSaltedS2K,
 			S2KCount: 65536,
 			Hash:     crypto.SHA256,
-		} ,
+		},
 		DefaultCipher: CipherAES256,
 	}
 	return pk.EncryptWithConfig(passphrase, config)
@@ -601,6 +822,14 @@ func (pk *PrivateKey) serializePrivateKey(w io.Writer) (err error) {
 		err = serializeEdDSAPrivateKey(w, priv)
 	case *ecdh.PrivateKey:
 		err = serializeECDHPrivateKey(w, priv)
+	case *x25519.PrivateKey:
+		err = serializeX25519PrivateKey(w, priv)
+	case *x448.PrivateKey:
+		err = serializeX448PrivateKey(w, priv)
+	case *ed25519.PrivateKey:
+		err = serializeEd25519PrivateKey(w, priv)
+	case *ed448.PrivateKey:
+		err = serializeEd448PrivateKey(w, priv)
 	default:
 		err = errors.InvalidArgumentError("unknown private key type")
 	}
@@ -621,8 +850,18 @@ func (pk *PrivateKey) parsePrivateKey(data []byte) (err error) {
 		return pk.parseECDHPrivateKey(data)
 	case PubKeyAlgoEdDSA:
 		return pk.parseEdDSAPrivateKey(data)
+	case PubKeyAlgoX25519:
+		return pk.parseX25519PrivateKey(data)
+	case PubKeyAlgoX448:
+		return pk.parseX448PrivateKey(data)
+	case PubKeyAlgoEd25519:
+		return pk.parseEd25519PrivateKey(data)
+	case PubKeyAlgoEd448:
+		return pk.parseEd448PrivateKey(data)
+	default:
+		err = errors.StructuralError("unknown private key type")
+		return
 	}
-	panic("impossible")
 }
 
 func (pk *PrivateKey) parseRSAPrivateKey(data []byte) (err error) {
@@ -743,6 +982,86 @@ func (pk *PrivateKey) parseECDHPrivateKey(data []byte) (err error) {
 	return nil
 }
 
+func (pk *PrivateKey) parseX25519PrivateKey(data []byte) (err error) {
+	publicKey := pk.PublicKey.PublicKey.(*x25519.PublicKey)
+	privateKey := x25519.NewPrivateKey(*publicKey)
+	privateKey.PublicKey = *publicKey
+
+	privateKey.Secret = make([]byte, x25519.KeySize)
+
+	if len(data) != x25519.KeySize {
+		err = errors.StructuralError("wrong x25519 key size")
+		return err
+	}
+	subtle.ConstantTimeCopy(1, privateKey.Secret, data)
+	if err = x25519.Validate(privateKey); err != nil {
+		return err
+	}
+	pk.PrivateKey = privateKey
+	return nil
+}
+
+func (pk *PrivateKey) parseX448PrivateKey(data []byte) (err error) {
+	publicKey := pk.PublicKey.PublicKey.(*x448.PublicKey)
+	privateKey := x448.NewPrivateKey(*publicKey)
+	privateKey.PublicKey = *publicKey
+
+	privateKey.Secret = make([]byte, x448.KeySize)
+
+	if len(data) != x448.KeySize {
+		err = errors.StructuralError("wrong x448 key size")
+		return err
+	}
+	subtle.ConstantTimeCopy(1, privateKey.Secret, data)
+	if err = x448.Validate(privateKey); err != nil {
+		return err
+	}
+	pk.PrivateKey = privateKey
+	return nil
+}
+
+func (pk *PrivateKey) parseEd25519PrivateKey(data []byte) (err error) {
+	publicKey := pk.PublicKey.PublicKey.(*ed25519.PublicKey)
+	privateKey := ed25519.NewPrivateKey(*publicKey)
+	privateKey.PublicKey = *publicKey
+
+	if len(data) != ed25519.SeedSize {
+		err = errors.StructuralError("wrong ed25519 key size")
+		return err
+	}
+	err = privateKey.UnmarshalByteSecret(data)
+	if err != nil {
+		return err
+	}
+	err = ed25519.Validate(privateKey)
+	if err != nil {
+		return err
+	}
+	pk.PrivateKey = privateKey
+	return nil
+}
+
+func (pk *PrivateKey) parseEd448PrivateKey(data []byte) (err error) {
+	publicKey := pk.PublicKey.PublicKey.(*ed448.PublicKey)
+	privateKey := ed448.NewPrivateKey(*publicKey)
+	privateKey.PublicKey = *publicKey
+
+	if len(data) != ed448.SeedSize {
+		err = errors.StructuralError("wrong ed448 key size")
+		return err
+	}
+	err = privateKey.UnmarshalByteSecret(data)
+	if err != nil {
+		return err
+	}
+	err = ed448.Validate(privateKey)
+	if err != nil {
+		return err
+	}
+	pk.PrivateKey = privateKey
+	return nil
+}
+
 func (pk *PrivateKey) parseEdDSAPrivateKey(data []byte) (err error) {
 	eddsaPub := pk.PublicKey.PublicKey.(*eddsa.PublicKey)
 	eddsaPriv := eddsa.NewPrivateKey(*eddsaPub)
@@ -767,6 +1086,41 @@ func (pk *PrivateKey) parseEdDSAPrivateKey(data []byte) (err error) {
 	return nil
 }
 
+func (pk *PrivateKey) additionalData() ([]byte, error) {
+	additionalData := bytes.NewBuffer(nil)
+	// Write additional data prefix based on packet type
+	var packetByte byte
+	if pk.PublicKey.IsSubkey {
+		packetByte = 0xc7
+	} else {
+		packetByte = 0xc5
+	}
+	// Write public key to additional data
+	_, err := additionalData.Write([]byte{packetByte})
+	if err != nil {
+		return nil, err
+	}
+	err = pk.PublicKey.serializeWithoutHeaders(additionalData)
+	if err != nil {
+		return nil, err
+	}
+	return additionalData.Bytes(), nil
+}
+
+func (pk *PrivateKey) applyHKDF(inputKey []byte) []byte {
+	var packetByte byte
+	if pk.PublicKey.IsSubkey {
+		packetByte = 0xc7
+	} else {
+		packetByte = 0xc5
+	}
+	associatedData := []byte{packetByte, byte(pk.Version), byte(pk.cipher), byte(pk.aead)}
+	hkdfReader := hkdf.New(sha256.New, inputKey, []byte{}, associatedData)
+	encryptionKey := make([]byte, pk.cipher.KeySize())
+	_, _ = readFull(hkdfReader, encryptionKey)
+	return encryptionKey
+}
+
 func validateDSAParameters(priv *dsa.PrivateKey) error {
 	p := priv.P // group prime
 	q := priv.Q // subgroup order

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/public_key.go

@@ -5,7 +5,6 @@
 package packet
 
 import (
-	"crypto"
 	"crypto/dsa"
 	"crypto/rsa"
 	"crypto/sha1"
@@ -21,23 +20,24 @@ import (
 
 	"github.com/ProtonMail/go-crypto/openpgp/ecdh"
 	"github.com/ProtonMail/go-crypto/openpgp/ecdsa"
+	"github.com/ProtonMail/go-crypto/openpgp/ed25519"
+	"github.com/ProtonMail/go-crypto/openpgp/ed448"
 	"github.com/ProtonMail/go-crypto/openpgp/eddsa"
 	"github.com/ProtonMail/go-crypto/openpgp/elgamal"
 	"github.com/ProtonMail/go-crypto/openpgp/errors"
 	"github.com/ProtonMail/go-crypto/openpgp/internal/algorithm"
 	"github.com/ProtonMail/go-crypto/openpgp/internal/ecc"
 	"github.com/ProtonMail/go-crypto/openpgp/internal/encoding"
+	"github.com/ProtonMail/go-crypto/openpgp/x25519"
+	"github.com/ProtonMail/go-crypto/openpgp/x448"
 )
 
-type kdfHashFunction byte
-type kdfAlgorithm byte
-
 // PublicKey represents an OpenPGP public key. See RFC 4880, section 5.5.2.
 type PublicKey struct {
 	Version      int
 	CreationTime time.Time
 	PubKeyAlgo   PublicKeyAlgorithm
-	PublicKey    interface{} // *rsa.PublicKey, *dsa.PublicKey, *ecdsa.PublicKey or *eddsa.PublicKey
+	PublicKey    interface{} // *rsa.PublicKey, *dsa.PublicKey, *ecdsa.PublicKey or *eddsa.PublicKey, *x25519.PublicKey, *x448.PublicKey, *ed25519.PublicKey, *ed448.PublicKey
 	Fingerprint  []byte
 	KeyId        uint64
 	IsSubkey     bool
@@ -61,11 +61,19 @@ func (pk *PublicKey) UpgradeToV5() {
 	pk.setFingerprintAndKeyId()
 }
 
+// UpgradeToV6 updates the version of the key to v6, and updates all necessary
+// fields.
+func (pk *PublicKey) UpgradeToV6() error {
+	pk.Version = 6
+	pk.setFingerprintAndKeyId()
+	return pk.checkV6Compatibility()
+}
+
 // signingKey provides a convenient abstraction over signature verification
 // for v3 and v4 public keys.
 type signingKey interface {
 	SerializeForHash(io.Writer) error
-	SerializeSignaturePrefix(io.Writer)
+	SerializeSignaturePrefix(io.Writer) error
 	serializeWithoutHeaders(io.Writer) error
 }
 
@@ -174,6 +182,54 @@ func NewEdDSAPublicKey(creationTime time.Time, pub *eddsa.PublicKey) *PublicKey
 	return pk
 }
 
+func NewX25519PublicKey(creationTime time.Time, pub *x25519.PublicKey) *PublicKey {
+	pk := &PublicKey{
+		Version:      4,
+		CreationTime: creationTime,
+		PubKeyAlgo:   PubKeyAlgoX25519,
+		PublicKey:    pub,
+	}
+
+	pk.setFingerprintAndKeyId()
+	return pk
+}
+
+func NewX448PublicKey(creationTime time.Time, pub *x448.PublicKey) *PublicKey {
+	pk := &PublicKey{
+		Version:      4,
+		CreationTime: creationTime,
+		PubKeyAlgo:   PubKeyAlgoX448,
+		PublicKey:    pub,
+	}
+
+	pk.setFingerprintAndKeyId()
+	return pk
+}
+
+func NewEd25519PublicKey(creationTime time.Time, pub *ed25519.PublicKey) *PublicKey {
+	pk := &PublicKey{
+		Version:      4,
+		CreationTime: creationTime,
+		PubKeyAlgo:   PubKeyAlgoEd25519,
+		PublicKey:    pub,
+	}
+
+	pk.setFingerprintAndKeyId()
+	return pk
+}
+
+func NewEd448PublicKey(creationTime time.Time, pub *ed448.PublicKey) *PublicKey {
+	pk := &PublicKey{
+		Version:      4,
+		CreationTime: creationTime,
+		PubKeyAlgo:   PubKeyAlgoEd448,
+		PublicKey:    pub,
+	}
+
+	pk.setFingerprintAndKeyId()
+	return pk
+}
+
 func (pk *PublicKey) parse(r io.Reader) (err error) {
 	// RFC 4880, section 5.5.2
 	var buf [6]byte
@@ -181,12 +237,19 @@ func (pk *PublicKey) parse(r io.Reader) (err error) {
 	if err != nil {
 		return
 	}
-	if buf[0] != 4 && buf[0] != 5 {
+
+	pk.Version = int(buf[0])
+	if pk.Version != 4 && pk.Version != 5 && pk.Version != 6 {
 		return errors.UnsupportedError("public key version " + strconv.Itoa(int(buf[0])))
 	}
 
-	pk.Version = int(buf[0])
-	if pk.Version == 5 {
+	if V5Disabled && pk.Version == 5 {
+		return errors.UnsupportedError("support for parsing v5 entities is disabled; build with `-tags v5` if needed")
+	}
+
+	if pk.Version >= 5 {
+		// Read the four-octet scalar octet count
+		// The count is not used in this implementation
 		var n [4]byte
 		_, err = readFull(r, n[:])
 		if err != nil {
@@ -195,6 +258,7 @@ func (pk *PublicKey) parse(r io.Reader) (err error) {
 	}
 	pk.CreationTime = time.Unix(int64(uint32(buf[1])<<24|uint32(buf[2])<<16|uint32(buf[3])<<8|uint32(buf[4])), 0)
 	pk.PubKeyAlgo = PublicKeyAlgorithm(buf[5])
+	// Ignore four-ocet length
 	switch pk.PubKeyAlgo {
 	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
 		err = pk.parseRSA(r)
@@ -208,6 +272,14 @@ func (pk *PublicKey) parse(r io.Reader) (err error) {
 		err = pk.parseECDH(r)
 	case PubKeyAlgoEdDSA:
 		err = pk.parseEdDSA(r)
+	case PubKeyAlgoX25519:
+		err = pk.parseX25519(r)
+	case PubKeyAlgoX448:
+		err = pk.parseX448(r)
+	case PubKeyAlgoEd25519:
+		err = pk.parseEd25519(r)
+	case PubKeyAlgoEd448:
+		err = pk.parseEd448(r)
 	default:
 		err = errors.UnsupportedError("public key type: " + strconv.Itoa(int(pk.PubKeyAlgo)))
 	}
@@ -221,21 +293,44 @@ func (pk *PublicKey) parse(r io.Reader) (err error) {
 
 func (pk *PublicKey) setFingerprintAndKeyId() {
 	// RFC 4880, section 12.2
-	if pk.Version == 5 {
+	if pk.Version >= 5 {
 		fingerprint := sha256.New()
-		pk.SerializeForHash(fingerprint)
+		if err := pk.SerializeForHash(fingerprint); err != nil {
+			// Should not happen for a hash.
+			panic(err)
+		}
 		pk.Fingerprint = make([]byte, 32)
 		copy(pk.Fingerprint, fingerprint.Sum(nil))
 		pk.KeyId = binary.BigEndian.Uint64(pk.Fingerprint[:8])
 	} else {
 		fingerprint := sha1.New()
-		pk.SerializeForHash(fingerprint)
+		if err := pk.SerializeForHash(fingerprint); err != nil {
+			// Should not happen for a hash.
+			panic(err)
+		}
 		pk.Fingerprint = make([]byte, 20)
 		copy(pk.Fingerprint, fingerprint.Sum(nil))
 		pk.KeyId = binary.BigEndian.Uint64(pk.Fingerprint[12:20])
 	}
 }
 
+func (pk *PublicKey) checkV6Compatibility() error {
+	// Implementations MUST NOT accept or generate version 6 key material using the deprecated OIDs.
+	switch pk.PubKeyAlgo {
+	case PubKeyAlgoECDH:
+		curveInfo := ecc.FindByOid(pk.oid)
+		if curveInfo == nil {
+			return errors.UnsupportedError(fmt.Sprintf("unknown oid: %x", pk.oid))
+		}
+		if curveInfo.GenName == ecc.Curve25519GenName {
+			return errors.StructuralError("cannot generate v6 key with deprecated OID: Curve25519Legacy")
+		}
+	case PubKeyAlgoEdDSA:
+		return errors.StructuralError("cannot generate v6 key with deprecated algorithm: EdDSALegacy")
+	}
+	return nil
+}
+
 // parseRSA parses RSA public key material from the given Reader. See RFC 4880,
 // section 5.5.2.
 func (pk *PublicKey) parseRSA(r io.Reader) (err error) {
@@ -324,16 +419,17 @@ func (pk *PublicKey) parseECDSA(r io.Reader) (err error) {
 	if _, err = pk.oid.ReadFrom(r); err != nil {
 		return
 	}
-	pk.p = new(encoding.MPI)
-	if _, err = pk.p.ReadFrom(r); err != nil {
-		return
-	}
 
 	curveInfo := ecc.FindByOid(pk.oid)
 	if curveInfo == nil {
 		return errors.UnsupportedError(fmt.Sprintf("unknown oid: %x", pk.oid))
 	}
 
+	pk.p = new(encoding.MPI)
+	if _, err = pk.p.ReadFrom(r); err != nil {
+		return
+	}
+
 	c, ok := curveInfo.Curve.(ecc.ECDSACurve)
 	if !ok {
 		return errors.UnsupportedError(fmt.Sprintf("unsupported oid: %x", pk.oid))
@@ -353,6 +449,17 @@ func (pk *PublicKey) parseECDH(r io.Reader) (err error) {
 	if _, err = pk.oid.ReadFrom(r); err != nil {
 		return
 	}
+
+	curveInfo := ecc.FindByOid(pk.oid)
+	if curveInfo == nil {
+		return errors.UnsupportedError(fmt.Sprintf("unknown oid: %x", pk.oid))
+	}
+
+	if pk.Version == 6 && curveInfo.GenName == ecc.Curve25519GenName {
+		// Implementations MUST NOT accept or generate version 6 key material using the deprecated OIDs.
+		return errors.StructuralError("cannot read v6 key with deprecated OID: Curve25519Legacy")
+	}
+
 	pk.p = new(encoding.MPI)
 	if _, err = pk.p.ReadFrom(r); err != nil {
 		return
@@ -362,12 +469,6 @@ func (pk *PublicKey) parseECDH(r io.Reader) (err error) {
 		return
 	}
 
-	curveInfo := ecc.FindByOid(pk.oid)
-
-	if curveInfo == nil {
-		return errors.UnsupportedError(fmt.Sprintf("unknown oid: %x", pk.oid))
-	}
-
 	c, ok := curveInfo.Curve.(ecc.ECDHCurve)
 	if !ok {
 		return errors.UnsupportedError(fmt.Sprintf("unsupported oid: %x", pk.oid))
@@ -396,10 +497,16 @@ func (pk *PublicKey) parseECDH(r io.Reader) (err error) {
 }
 
 func (pk *PublicKey) parseEdDSA(r io.Reader) (err error) {
+	if pk.Version == 6 {
+		// Implementations MUST NOT accept or generate version 6 key material using the deprecated OIDs.
+		return errors.StructuralError("cannot generate v6 key with deprecated algorithm: EdDSALegacy")
+	}
+
 	pk.oid = new(encoding.OID)
 	if _, err = pk.oid.ReadFrom(r); err != nil {
 		return
 	}
+
 	curveInfo := ecc.FindByOid(pk.oid)
 	if curveInfo == nil {
 		return errors.UnsupportedError(fmt.Sprintf("unknown oid: %x", pk.oid))
@@ -435,75 +542,145 @@ func (pk *PublicKey) parseEdDSA(r io.Reader) (err error) {
 	return
 }
 
+func (pk *PublicKey) parseX25519(r io.Reader) (err error) {
+	point := make([]byte, x25519.KeySize)
+	_, err = io.ReadFull(r, point)
+	if err != nil {
+		return
+	}
+	pub := &x25519.PublicKey{
+		Point: point,
+	}
+	pk.PublicKey = pub
+	return
+}
+
+func (pk *PublicKey) parseX448(r io.Reader) (err error) {
+	point := make([]byte, x448.KeySize)
+	_, err = io.ReadFull(r, point)
+	if err != nil {
+		return
+	}
+	pub := &x448.PublicKey{
+		Point: point,
+	}
+	pk.PublicKey = pub
+	return
+}
+
+func (pk *PublicKey) parseEd25519(r io.Reader) (err error) {
+	point := make([]byte, ed25519.PublicKeySize)
+	_, err = io.ReadFull(r, point)
+	if err != nil {
+		return
+	}
+	pub := &ed25519.PublicKey{
+		Point: point,
+	}
+	pk.PublicKey = pub
+	return
+}
+
+func (pk *PublicKey) parseEd448(r io.Reader) (err error) {
+	point := make([]byte, ed448.PublicKeySize)
+	_, err = io.ReadFull(r, point)
+	if err != nil {
+		return
+	}
+	pub := &ed448.PublicKey{
+		Point: point,
+	}
+	pk.PublicKey = pub
+	return
+}
+
 // SerializeForHash serializes the PublicKey to w with the special packet
 // header format needed for hashing.
 func (pk *PublicKey) SerializeForHash(w io.Writer) error {
-	pk.SerializeSignaturePrefix(w)
+	if err := pk.SerializeSignaturePrefix(w); err != nil {
+		return err
+	}
 	return pk.serializeWithoutHeaders(w)
 }
 
 // SerializeSignaturePrefix writes the prefix for this public key to the given Writer.
 // The prefix is used when calculating a signature over this public key. See
 // RFC 4880, section 5.2.4.
-func (pk *PublicKey) SerializeSignaturePrefix(w io.Writer) {
+func (pk *PublicKey) SerializeSignaturePrefix(w io.Writer) error {
 	var pLength = pk.algorithmSpecificByteCount()
-	if pk.Version == 5 {
-		pLength += 10 // version, timestamp (4), algorithm, key octet count (4).
-		w.Write([]byte{
-			0x9A,
+	// version, timestamp, algorithm
+	pLength += versionSize + timestampSize + algorithmSize
+	if pk.Version >= 5 {
+		// key octet count (4).
+		pLength += 4
+		_, err := w.Write([]byte{
+			// When a v4 signature is made over a key, the hash data starts with the octet 0x99, followed by a two-octet length
+			// of the key, and then the body of the key packet. When a v6 signature is made over a key, the hash data starts
+			// with the salt, then octet 0x9B, followed by a four-octet length of the key, and then the body of the key packet.
+			0x95 + byte(pk.Version),
 			byte(pLength >> 24),
 			byte(pLength >> 16),
 			byte(pLength >> 8),
 			byte(pLength),
 		})
-		return
+		return err
 	}
-	pLength += 6
-	w.Write([]byte{0x99, byte(pLength >> 8), byte(pLength)})
+	if _, err := w.Write([]byte{0x99, byte(pLength >> 8), byte(pLength)}); err != nil {
+		return err
+	}
+	return nil
 }
 
 func (pk *PublicKey) Serialize(w io.Writer) (err error) {
-	length := 6 // 6 byte header
+	length := uint32(versionSize + timestampSize + algorithmSize) // 6 byte header
 	length += pk.algorithmSpecificByteCount()
-	if pk.Version == 5 {
+	if pk.Version >= 5 {
 		length += 4 // octet key count
 	}
 	packetType := packetTypePublicKey
 	if pk.IsSubkey {
 		packetType = packetTypePublicSubkey
 	}
-	err = serializeHeader(w, packetType, length)
+	err = serializeHeader(w, packetType, int(length))
 	if err != nil {
 		return
 	}
 	return pk.serializeWithoutHeaders(w)
 }
 
-func (pk *PublicKey) algorithmSpecificByteCount() int {
-	length := 0
+func (pk *PublicKey) algorithmSpecificByteCount() uint32 {
+	length := uint32(0)
 	switch pk.PubKeyAlgo {
 	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
-		length += int(pk.n.EncodedLength())
-		length += int(pk.e.EncodedLength())
+		length += uint32(pk.n.EncodedLength())
+		length += uint32(pk.e.EncodedLength())
 	case PubKeyAlgoDSA:
-		length += int(pk.p.EncodedLength())
-		length += int(pk.q.EncodedLength())
-		length += int(pk.g.EncodedLength())
-		length += int(pk.y.EncodedLength())
+		length += uint32(pk.p.EncodedLength())
+		length += uint32(pk.q.EncodedLength())
+		length += uint32(pk.g.EncodedLength())
+		length += uint32(pk.y.EncodedLength())
 	case PubKeyAlgoElGamal:
-		length += int(pk.p.EncodedLength())
-		length += int(pk.g.EncodedLength())
-		length += int(pk.y.EncodedLength())
+		length += uint32(pk.p.EncodedLength())
+		length += uint32(pk.g.EncodedLength())
+		length += uint32(pk.y.EncodedLength())
 	case PubKeyAlgoECDSA:
-		length += int(pk.oid.EncodedLength())
-		length += int(pk.p.EncodedLength())
+		length += uint32(pk.oid.EncodedLength())
+		length += uint32(pk.p.EncodedLength())
 	case PubKeyAlgoECDH:
-		length += int(pk.oid.EncodedLength())
-		length += int(pk.p.EncodedLength())
-		length += int(pk.kdf.EncodedLength())
+		length += uint32(pk.oid.EncodedLength())
+		length += uint32(pk.p.EncodedLength())
+		length += uint32(pk.kdf.EncodedLength())
 	case PubKeyAlgoEdDSA:
-		length += int(pk.oid.EncodedLength())
-		length += int(pk.p.EncodedLength())
+		length += uint32(pk.oid.EncodedLength())
+		length += uint32(pk.p.EncodedLength())
+	case PubKeyAlgoX25519:
+		length += x25519.KeySize
+	case PubKeyAlgoX448:
+		length += x448.KeySize
+	case PubKeyAlgoEd25519:
+		length += ed25519.PublicKeySize
+	case PubKeyAlgoEd448:
+		length += ed448.PublicKeySize
 	default:
 		panic("unknown public key algorithm")
 	}
@@ -522,7 +699,7 @@ func (pk *PublicKey) serializeWithoutHeaders(w io.Writer) (err error) {
 		return
 	}
 
-	if pk.Version == 5 {
+	if pk.Version >= 5 {
 		n := pk.algorithmSpecificByteCount()
 		if _, err = w.Write([]byte{
 			byte(n >> 24), byte(n >> 16), byte(n >> 8), byte(n),
@@ -580,6 +757,22 @@ func (pk *PublicKey) serializeWithoutHeaders(w io.Writer) (err error) {
 		}
 		_, err = w.Write(pk.p.EncodedBytes())
 		return
+	case PubKeyAlgoX25519:
+		publicKey := pk.PublicKey.(*x25519.PublicKey)
+		_, err = w.Write(publicKey.Point)
+		return
+	case PubKeyAlgoX448:
+		publicKey := pk.PublicKey.(*x448.PublicKey)
+		_, err = w.Write(publicKey.Point)
+		return
+	case PubKeyAlgoEd25519:
+		publicKey := pk.PublicKey.(*ed25519.PublicKey)
+		_, err = w.Write(publicKey.Point)
+		return
+	case PubKeyAlgoEd448:
+		publicKey := pk.PublicKey.(*ed448.PublicKey)
+		_, err = w.Write(publicKey.Point)
+		return
 	}
 	return errors.InvalidArgumentError("bad public-key algorithm")
 }
@@ -589,6 +782,20 @@ func (pk *PublicKey) CanSign() bool {
 	return pk.PubKeyAlgo != PubKeyAlgoRSAEncryptOnly && pk.PubKeyAlgo != PubKeyAlgoElGamal && pk.PubKeyAlgo != PubKeyAlgoECDH
 }
 
+// VerifyHashTag returns nil iff sig appears to be a plausible signature of the data
+// hashed into signed, based solely on its HashTag. signed is mutated by this call.
+func VerifyHashTag(signed hash.Hash, sig *Signature) (err error) {
+	if sig.Version == 5 && (sig.SigType == 0x00 || sig.SigType == 0x01) {
+		sig.AddMetadataToHashSuffix()
+	}
+	signed.Write(sig.HashSuffix)
+	hashBytes := signed.Sum(nil)
+	if hashBytes[0] != sig.HashTag[0] || hashBytes[1] != sig.HashTag[1] {
+		return errors.SignatureError("hash tag doesn't match")
+	}
+	return nil
+}
+
 // VerifySignature returns nil iff sig is a valid signature, made by this
 // public key, of the data hashed into signed. signed is mutated by this call.
 func (pk *PublicKey) VerifySignature(signed hash.Hash, sig *Signature) (err error) {
@@ -600,7 +807,8 @@ func (pk *PublicKey) VerifySignature(signed hash.Hash, sig *Signature) (err erro
 	}
 	signed.Write(sig.HashSuffix)
 	hashBytes := signed.Sum(nil)
-	if sig.Version == 5 && (hashBytes[0] != sig.HashTag[0] || hashBytes[1] != sig.HashTag[1]) {
+	// see discussion https://github.com/ProtonMail/go-crypto/issues/107
+	if sig.Version >= 5 && (hashBytes[0] != sig.HashTag[0] || hashBytes[1] != sig.HashTag[1]) {
 		return errors.SignatureError("hash tag doesn't match")
 	}
 
@@ -639,6 +847,18 @@ func (pk *PublicKey) VerifySignature(signed hash.Hash, sig *Signature) (err erro
 			return errors.SignatureError("EdDSA verification failure")
 		}
 		return nil
+	case PubKeyAlgoEd25519:
+		ed25519PublicKey := pk.PublicKey.(*ed25519.PublicKey)
+		if !ed25519.Verify(ed25519PublicKey, hashBytes, sig.EdSig) {
+			return errors.SignatureError("Ed25519 verification failure")
+		}
+		return nil
+	case PubKeyAlgoEd448:
+		ed448PublicKey := pk.PublicKey.(*ed448.PublicKey)
+		if !ed448.Verify(ed448PublicKey, hashBytes, sig.EdSig) {
+			return errors.SignatureError("ed448 verification failure")
+		}
+		return nil
 	default:
 		return errors.SignatureError("Unsupported public key algorithm used in signature")
 	}
@@ -646,11 +866,8 @@ func (pk *PublicKey) VerifySignature(signed hash.Hash, sig *Signature) (err erro
 
 // keySignatureHash returns a Hash of the message that needs to be signed for
 // pk to assert a subkey relationship to signed.
-func keySignatureHash(pk, signed signingKey, hashFunc crypto.Hash) (h hash.Hash, err error) {
-	if !hashFunc.Available() {
-		return nil, errors.UnsupportedError("hash function")
-	}
-	h = hashFunc.New()
+func keySignatureHash(pk, signed signingKey, hashFunc hash.Hash) (h hash.Hash, err error) {
+	h = hashFunc
 
 	// RFC 4880, section 5.2.4
 	err = pk.SerializeForHash(h)
@@ -662,10 +879,28 @@ func keySignatureHash(pk, signed signingKey, hashFunc crypto.Hash) (h hash.Hash,
 	return
 }
 
+// VerifyKeyHashTag returns nil iff sig appears to be a plausible signature over this
+// primary key and subkey, based solely on its HashTag.
+func (pk *PublicKey) VerifyKeyHashTag(signed *PublicKey, sig *Signature) error {
+	preparedHash, err := sig.PrepareVerify()
+	if err != nil {
+		return err
+	}
+	h, err := keySignatureHash(pk, signed, preparedHash)
+	if err != nil {
+		return err
+	}
+	return VerifyHashTag(h, sig)
+}
+
 // VerifyKeySignature returns nil iff sig is a valid signature, made by this
 // public key, of signed.
 func (pk *PublicKey) VerifyKeySignature(signed *PublicKey, sig *Signature) error {
-	h, err := keySignatureHash(pk, signed, sig.Hash)
+	preparedHash, err := sig.PrepareVerify()
+	if err != nil {
+		return err
+	}
+	h, err := keySignatureHash(pk, signed, preparedHash)
 	if err != nil {
 		return err
 	}
@@ -679,10 +914,14 @@ func (pk *PublicKey) VerifyKeySignature(signed *PublicKey, sig *Signature) error
 		if sig.EmbeddedSignature == nil {
 			return errors.StructuralError("signing subkey is missing cross-signature")
 		}
+		preparedHashEmbedded, err := sig.EmbeddedSignature.PrepareVerify()
+		if err != nil {
+			return err
+		}
 		// Verify the cross-signature. This is calculated over the same
 		// data as the main signature, so we cannot just recursively
 		// call signed.VerifyKeySignature(...)
-		if h, err = keySignatureHash(pk, signed, sig.EmbeddedSignature.Hash); err != nil {
+		if h, err = keySignatureHash(pk, signed, preparedHashEmbedded); err != nil {
 			return errors.StructuralError("error while hashing for cross-signature: " + err.Error())
 		}
 		if err := signed.VerifySignature(h, sig.EmbeddedSignature); err != nil {
@@ -693,32 +932,44 @@ func (pk *PublicKey) VerifyKeySignature(signed *PublicKey, sig *Signature) error
 	return nil
 }
 
-func keyRevocationHash(pk signingKey, hashFunc crypto.Hash) (h hash.Hash, err error) {
-	if !hashFunc.Available() {
-		return nil, errors.UnsupportedError("hash function")
+func keyRevocationHash(pk signingKey, hashFunc hash.Hash) (err error) {
+	return pk.SerializeForHash(hashFunc)
+}
+
+// VerifyRevocationHashTag returns nil iff sig appears to be a plausible signature
+// over this public key, based solely on its HashTag.
+func (pk *PublicKey) VerifyRevocationHashTag(sig *Signature) (err error) {
+	preparedHash, err := sig.PrepareVerify()
+	if err != nil {
+		return err
 	}
-	h = hashFunc.New()
-
-	// RFC 4880, section 5.2.4
-	err = pk.SerializeForHash(h)
-
-	return
+	if err = keyRevocationHash(pk, preparedHash); err != nil {
+		return err
+	}
+	return VerifyHashTag(preparedHash, sig)
 }
 
 // VerifyRevocationSignature returns nil iff sig is a valid signature, made by this
 // public key.
 func (pk *PublicKey) VerifyRevocationSignature(sig *Signature) (err error) {
-	h, err := keyRevocationHash(pk, sig.Hash)
+	preparedHash, err := sig.PrepareVerify()
 	if err != nil {
 		return err
 	}
-	return pk.VerifySignature(h, sig)
+	if err = keyRevocationHash(pk, preparedHash); err != nil {
+		return err
+	}
+	return pk.VerifySignature(preparedHash, sig)
 }
 
 // VerifySubkeyRevocationSignature returns nil iff sig is a valid subkey revocation signature,
 // made by this public key, of signed.
 func (pk *PublicKey) VerifySubkeyRevocationSignature(sig *Signature, signed *PublicKey) (err error) {
-	h, err := keySignatureHash(pk, signed, sig.Hash)
+	preparedHash, err := sig.PrepareVerify()
+	if err != nil {
+		return err
+	}
+	h, err := keySignatureHash(pk, signed, preparedHash)
 	if err != nil {
 		return err
 	}
@@ -727,15 +978,15 @@ func (pk *PublicKey) VerifySubkeyRevocationSignature(sig *Signature, signed *Pub
 
 // userIdSignatureHash returns a Hash of the message that needs to be signed
 // to assert that pk is a valid key for id.
-func userIdSignatureHash(id string, pk *PublicKey, hashFunc crypto.Hash) (h hash.Hash, err error) {
-	if !hashFunc.Available() {
-		return nil, errors.UnsupportedError("hash function")
-	}
-	h = hashFunc.New()
+func userIdSignatureHash(id string, pk *PublicKey, h hash.Hash) (err error) {
 
 	// RFC 4880, section 5.2.4
-	pk.SerializeSignaturePrefix(h)
-	pk.serializeWithoutHeaders(h)
+	if err := pk.SerializeSignaturePrefix(h); err != nil {
+		return err
+	}
+	if err := pk.serializeWithoutHeaders(h); err != nil {
+		return err
+	}
 
 	var buf [5]byte
 	buf[0] = 0xb4
@@ -746,16 +997,51 @@ func userIdSignatureHash(id string, pk *PublicKey, hashFunc crypto.Hash) (h hash
 	h.Write(buf[:])
 	h.Write([]byte(id))
 
-	return
+	return nil
+}
+
+// directKeySignatureHash returns a Hash of the message that needs to be signed.
+func directKeySignatureHash(pk *PublicKey, h hash.Hash) (err error) {
+	return pk.SerializeForHash(h)
+}
+
+// VerifyUserIdHashTag returns nil iff sig appears to be a plausible signature over this
+// public key and UserId, based solely on its HashTag
+func (pk *PublicKey) VerifyUserIdHashTag(id string, sig *Signature) (err error) {
+	preparedHash, err := sig.PrepareVerify()
+	if err != nil {
+		return err
+	}
+	err = userIdSignatureHash(id, pk, preparedHash)
+	if err != nil {
+		return err
+	}
+	return VerifyHashTag(preparedHash, sig)
 }
 
 // VerifyUserIdSignature returns nil iff sig is a valid signature, made by this
 // public key, that id is the identity of pub.
 func (pk *PublicKey) VerifyUserIdSignature(id string, pub *PublicKey, sig *Signature) (err error) {
-	h, err := userIdSignatureHash(id, pub, sig.Hash)
+	h, err := sig.PrepareVerify()
 	if err != nil {
 		return err
 	}
+	if err := userIdSignatureHash(id, pub, h); err != nil {
+		return err
+	}
+	return pk.VerifySignature(h, sig)
+}
+
+// VerifyDirectKeySignature returns nil iff sig is a valid signature, made by this
+// public key.
+func (pk *PublicKey) VerifyDirectKeySignature(sig *Signature) (err error) {
+	h, err := sig.PrepareVerify()
+	if err != nil {
+		return err
+	}
+	if err := directKeySignatureHash(pk, h); err != nil {
+		return err
+	}
 	return pk.VerifySignature(h, sig)
 }
 
@@ -786,21 +1072,49 @@ func (pk *PublicKey) BitLength() (bitLength uint16, err error) {
 		bitLength = pk.p.BitLength()
 	case PubKeyAlgoEdDSA:
 		bitLength = pk.p.BitLength()
+	case PubKeyAlgoX25519:
+		bitLength = x25519.KeySize * 8
+	case PubKeyAlgoX448:
+		bitLength = x448.KeySize * 8
+	case PubKeyAlgoEd25519:
+		bitLength = ed25519.PublicKeySize * 8
+	case PubKeyAlgoEd448:
+		bitLength = ed448.PublicKeySize * 8
 	default:
 		err = errors.InvalidArgumentError("bad public-key algorithm")
 	}
 	return
 }
 
+// Curve returns the used elliptic curve of this public key.
+// Returns an error if no elliptic curve is used.
+func (pk *PublicKey) Curve() (curve Curve, err error) {
+	switch pk.PubKeyAlgo {
+	case PubKeyAlgoECDSA, PubKeyAlgoECDH, PubKeyAlgoEdDSA:
+		curveInfo := ecc.FindByOid(pk.oid)
+		if curveInfo == nil {
+			return "", errors.UnsupportedError(fmt.Sprintf("unknown oid: %x", pk.oid))
+		}
+		curve = Curve(curveInfo.GenName)
+	case PubKeyAlgoEd25519, PubKeyAlgoX25519:
+		curve = Curve25519
+	case PubKeyAlgoEd448, PubKeyAlgoX448:
+		curve = Curve448
+	default:
+		err = errors.InvalidArgumentError("public key does not operate with an elliptic curve")
+	}
+	return
+}
+
 // KeyExpired returns whether sig is a self-signature of a key that has
 // expired or is created in the future.
 func (pk *PublicKey) KeyExpired(sig *Signature, currentTime time.Time) bool {
-	if pk.CreationTime.After(currentTime) {
+	if pk.CreationTime.Unix() > currentTime.Unix() {
 		return true
 	}
 	if sig.KeyLifetimeSecs == nil || *sig.KeyLifetimeSecs == 0 {
 		return false
 	}
 	expiry := pk.CreationTime.Add(time.Duration(*sig.KeyLifetimeSecs) * time.Second)
-	return currentTime.After(expiry)
+	return currentTime.Unix() > expiry.Unix()
 }

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/reader.go

@@ -10,6 +10,12 @@ import (
 	"github.com/ProtonMail/go-crypto/openpgp/errors"
 )
 
+type PacketReader interface {
+	Next() (p Packet, err error)
+	Push(reader io.Reader) (err error)
+	Unread(p Packet)
+}
+
 // Reader reads packets from an io.Reader and allows packets to be 'unread' so
 // that they result from the next call to Next.
 type Reader struct {
@@ -26,37 +32,81 @@ type Reader struct {
 const maxReaders = 32
 
 // Next returns the most recently unread Packet, or reads another packet from
-// the top-most io.Reader. Unknown packet types are skipped.
+// the top-most io.Reader. Unknown/unsupported/Marker packet types are skipped.
 func (r *Reader) Next() (p Packet, err error) {
+	for {
+		p, err := r.read()
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			if _, ok := err.(errors.UnknownPacketTypeError); ok {
+				continue
+			}
+			if _, ok := err.(errors.UnsupportedError); ok {
+				switch p.(type) {
+				case *SymmetricallyEncrypted, *AEADEncrypted, *Compressed, *LiteralData:
+					return nil, err
+				}
+				continue
+			}
+			return nil, err
+		} else {
+			//A marker packet MUST be ignored when received
+			switch p.(type) {
+			case *Marker:
+				continue
+			}
+			return p, nil
+		}
+	}
+	return nil, io.EOF
+}
+
+// Next returns the most recently unread Packet, or reads another packet from
+// the top-most io.Reader. Unknown/Marker packet types are skipped while unsupported
+// packets are returned as UnsupportedPacket type.
+func (r *Reader) NextWithUnsupported() (p Packet, err error) {
+	for {
+		p, err = r.read()
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			if _, ok := err.(errors.UnknownPacketTypeError); ok {
+				continue
+			}
+			if casteErr, ok := err.(errors.UnsupportedError); ok {
+				return &UnsupportedPacket{
+					IncompletePacket: p,
+					Error:            casteErr,
+				}, nil
+			}
+			return
+		} else {
+			//A marker packet MUST be ignored when received
+			switch p.(type) {
+			case *Marker:
+				continue
+			}
+			return
+		}
+	}
+	return nil, io.EOF
+}
+
+func (r *Reader) read() (p Packet, err error) {
 	if len(r.q) > 0 {
 		p = r.q[len(r.q)-1]
 		r.q = r.q[:len(r.q)-1]
 		return
 	}
-
 	for len(r.readers) > 0 {
 		p, err = Read(r.readers[len(r.readers)-1])
-		if err == nil {
-			return
-		}
 		if err == io.EOF {
 			r.readers = r.readers[:len(r.readers)-1]
 			continue
 		}
-		// TODO: Add strict mode that rejects unknown packets, instead of ignoring them.
-		if _, ok := err.(errors.UnknownPacketTypeError); ok {
-			continue
-		}
-		if _, ok := err.(errors.UnsupportedError); ok {
-			switch p.(type) {
-			case *SymmetricallyEncrypted, *AEADEncrypted, *Compressed, *LiteralData:
-				return nil, err
-			}
-			continue
-		}
-		return nil, err
+		return p, err
 	}
-
 	return nil, io.EOF
 }
 
@@ -84,3 +134,76 @@ func NewReader(r io.Reader) *Reader {
 		readers: []io.Reader{r},
 	}
 }
+
+// CheckReader is similar to Reader but additionally
+// uses the pushdown automata to verify the read packet sequence.
+type CheckReader struct {
+	Reader
+	verifier  *SequenceVerifier
+	fullyRead bool
+}
+
+// Next returns the most recently unread Packet, or reads another packet from
+// the top-most io.Reader. Unknown packet types are skipped.
+// If the read packet sequence does not conform to the packet composition
+// rules in rfc4880, it returns an error.
+func (r *CheckReader) Next() (p Packet, err error) {
+	if r.fullyRead {
+		return nil, io.EOF
+	}
+	if len(r.q) > 0 {
+		p = r.q[len(r.q)-1]
+		r.q = r.q[:len(r.q)-1]
+		return
+	}
+	var errMsg error
+	for len(r.readers) > 0 {
+		p, errMsg, err = ReadWithCheck(r.readers[len(r.readers)-1], r.verifier)
+		if errMsg != nil {
+			err = errMsg
+			return
+		}
+		if err == nil {
+			return
+		}
+		if err == io.EOF {
+			r.readers = r.readers[:len(r.readers)-1]
+			continue
+		}
+		//A marker packet MUST be ignored when received
+		switch p.(type) {
+		case *Marker:
+			continue
+		}
+		if _, ok := err.(errors.UnknownPacketTypeError); ok {
+			continue
+		}
+		if _, ok := err.(errors.UnsupportedError); ok {
+			switch p.(type) {
+			case *SymmetricallyEncrypted, *AEADEncrypted, *Compressed, *LiteralData:
+				return nil, err
+			}
+			continue
+		}
+		return nil, err
+	}
+	if errMsg = r.verifier.Next(EOSSymbol); errMsg != nil {
+		return nil, errMsg
+	}
+	if errMsg = r.verifier.AssertValid(); errMsg != nil {
+		return nil, errMsg
+	}
+	r.fullyRead = true
+	return nil, io.EOF
+}
+
+func NewCheckReader(r io.Reader) *CheckReader {
+	return &CheckReader{
+		Reader: Reader{
+			q:       nil,
+			readers: []io.Reader{r},
+		},
+		verifier:  NewSequenceVerifier(),
+		fullyRead: false,
+	}
+}

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/recipient.go

@@ -0,0 +1,15 @@
+package packet
+
+// Recipient type represents a Intended Recipient Fingerprint subpacket
+// See https://datatracker.ietf.org/doc/html/draft-ietf-openpgp-crypto-refresh#name-intended-recipient-fingerpr
+type Recipient struct {
+	KeyVersion  int
+	Fingerprint []byte
+}
+
+func (r *Recipient) Serialize() []byte {
+	packet := make([]byte, len(r.Fingerprint)+1)
+	packet[0] = byte(r.KeyVersion)
+	copy(packet[1:], r.Fingerprint)
+	return packet
+}

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/symmetric_key_encrypted.go

@@ -7,11 +7,13 @@ package packet
 import (
 	"bytes"
 	"crypto/cipher"
+	"crypto/sha256"
 	"io"
 	"strconv"
 
 	"github.com/ProtonMail/go-crypto/openpgp/errors"
 	"github.com/ProtonMail/go-crypto/openpgp/s2k"
+	"golang.org/x/crypto/hkdf"
 )
 
 // This is the largest session key that we'll support. Since at most 256-bit cipher
@@ -39,10 +41,21 @@ func (ske *SymmetricKeyEncrypted) parse(r io.Reader) error {
 		return err
 	}
 	ske.Version = int(buf[0])
-	if ske.Version != 4 && ske.Version != 5 {
+	if ske.Version != 4 && ske.Version != 5 && ske.Version != 6 {
 		return errors.UnsupportedError("unknown SymmetricKeyEncrypted version")
 	}
 
+	if V5Disabled && ske.Version == 5 {
+		return errors.UnsupportedError("support for parsing v5 entities is disabled; build with `-tags v5` if needed")
+	}
+
+	if ske.Version > 5 {
+		// Scalar octet count
+		if _, err := readFull(r, buf[:]); err != nil {
+			return err
+		}
+	}
+
 	// Cipher function
 	if _, err := readFull(r, buf[:]); err != nil {
 		return err
@@ -52,7 +65,7 @@ func (ske *SymmetricKeyEncrypted) parse(r io.Reader) error {
 		return errors.UnsupportedError("unknown cipher: " + strconv.Itoa(int(buf[0])))
 	}
 
-	if ske.Version == 5 {
+	if ske.Version >= 5 {
 		// AEAD mode
 		if _, err := readFull(r, buf[:]); err != nil {
 			return errors.StructuralError("cannot read AEAD octet from packet")
@@ -60,6 +73,13 @@ func (ske *SymmetricKeyEncrypted) parse(r io.Reader) error {
 		ske.Mode = AEADMode(buf[0])
 	}
 
+	if ske.Version > 5 {
+		// Scalar octet count
+		if _, err := readFull(r, buf[:]); err != nil {
+			return err
+		}
+	}
+
 	var err error
 	if ske.s2k, err = s2k.Parse(r); err != nil {
 		if _, ok := err.(errors.ErrDummyPrivateKey); ok {
@@ -68,7 +88,7 @@ func (ske *SymmetricKeyEncrypted) parse(r io.Reader) error {
 		return err
 	}
 
-	if ske.Version == 5 {
+	if ske.Version >= 5 {
 		// AEAD IV
 		iv := make([]byte, ske.Mode.IvLength())
 		_, err := readFull(r, iv)
@@ -109,8 +129,8 @@ func (ske *SymmetricKeyEncrypted) Decrypt(passphrase []byte) ([]byte, CipherFunc
 	case 4:
 		plaintextKey, cipherFunc, err := ske.decryptV4(key)
 		return plaintextKey, cipherFunc, err
-	case 5:
-		plaintextKey, err := ske.decryptV5(key)
+	case 5, 6:
+		plaintextKey, err := ske.aeadDecrypt(ske.Version, key)
 		return plaintextKey, CipherFunction(0), err
 	}
 	err := errors.UnsupportedError("unknown SymmetricKeyEncrypted version")
@@ -136,9 +156,9 @@ func (ske *SymmetricKeyEncrypted) decryptV4(key []byte) ([]byte, CipherFunction,
 	return plaintextKey, cipherFunc, nil
 }
 
-func (ske *SymmetricKeyEncrypted) decryptV5(key []byte) ([]byte, error) {
-	adata := []byte{0xc3, byte(5), byte(ske.CipherFunc), byte(ske.Mode)}
-	aead := getEncryptedKeyAeadInstance(ske.CipherFunc, ske.Mode, key, adata)
+func (ske *SymmetricKeyEncrypted) aeadDecrypt(version int, key []byte) ([]byte, error) {
+	adata := []byte{0xc3, byte(version), byte(ske.CipherFunc), byte(ske.Mode)}
+	aead := getEncryptedKeyAeadInstance(ske.CipherFunc, ske.Mode, key, adata, version)
 
 	plaintextKey, err := aead.Open(nil, ske.iv, ske.encryptedKey, adata)
 	if err != nil {
@@ -175,10 +195,22 @@ func SerializeSymmetricKeyEncrypted(w io.Writer, passphrase []byte, config *Conf
 // the given passphrase. The returned session key must be passed to
 // SerializeSymmetricallyEncrypted.
 // If config is nil, sensible defaults will be used.
+// Deprecated: Use SerializeSymmetricKeyEncryptedAEADReuseKey instead.
 func SerializeSymmetricKeyEncryptedReuseKey(w io.Writer, sessionKey []byte, passphrase []byte, config *Config) (err error) {
+	return SerializeSymmetricKeyEncryptedAEADReuseKey(w, sessionKey, passphrase, config.AEAD() != nil, config)
+}
+
+// SerializeSymmetricKeyEncryptedAEADReuseKey serializes a symmetric key packet to w.
+// The packet contains the given session key, encrypted by a key derived from
+// the given passphrase. The returned session key must be passed to
+// SerializeSymmetricallyEncrypted.
+// If aeadSupported is set, SKESK v6 is used, otherwise v4.
+// Note: aeadSupported MUST match the value passed to SerializeSymmetricallyEncrypted.
+// If config is nil, sensible defaults will be used.
+func SerializeSymmetricKeyEncryptedAEADReuseKey(w io.Writer, sessionKey []byte, passphrase []byte, aeadSupported bool, config *Config) (err error) {
 	var version int
-	if config.AEAD() != nil {
-		version = 5
+	if aeadSupported {
+		version = 6
 	} else {
 		version = 4
 	}
@@ -203,11 +235,15 @@ func SerializeSymmetricKeyEncryptedReuseKey(w io.Writer, sessionKey []byte, pass
 	switch version {
 	case 4:
 		packetLength = 2 /* header */ + len(s2kBytes) + 1 /* cipher type */ + keySize
-	case 5:
+	case 5, 6:
 		ivLen := config.AEAD().Mode().IvLength()
 		tagLen := config.AEAD().Mode().TagLength()
 		packetLength = 3 + len(s2kBytes) + ivLen + keySize + tagLen
 	}
+	if version > 5 {
+		packetLength += 2 // additional octet count fields
+	}
+
 	err = serializeHeader(w, packetTypeSymmetricKeyEncrypted, packetLength)
 	if err != nil {
 		return
@@ -216,13 +252,22 @@ func SerializeSymmetricKeyEncryptedReuseKey(w io.Writer, sessionKey []byte, pass
 	// Symmetric Key Encrypted Version
 	buf := []byte{byte(version)}
 
+	if version > 5 {
+		// Scalar octet count
+		buf = append(buf, byte(3+len(s2kBytes)+config.AEAD().Mode().IvLength()))
+	}
+
 	// Cipher function
 	buf = append(buf, byte(cipherFunc))
 
-	if version == 5 {
+	if version >= 5 {
 		// AEAD mode
 		buf = append(buf, byte(config.AEAD().Mode()))
 	}
+	if version > 5 {
+		// Scalar octet count
+		buf = append(buf, byte(len(s2kBytes)))
+	}
 	_, err = w.Write(buf)
 	if err != nil {
 		return
@@ -243,10 +288,10 @@ func SerializeSymmetricKeyEncryptedReuseKey(w io.Writer, sessionKey []byte, pass
 		if err != nil {
 			return
 		}
-	case 5:
+	case 5, 6:
 		mode := config.AEAD().Mode()
-		adata := []byte{0xc3, byte(5), byte(cipherFunc), byte(mode)}
-		aead := getEncryptedKeyAeadInstance(cipherFunc, mode, keyEncryptingKey, adata)
+		adata := []byte{0xc3, byte(version), byte(cipherFunc), byte(mode)}
+		aead := getEncryptedKeyAeadInstance(cipherFunc, mode, keyEncryptingKey, adata, version)
 
 		// Sample iv using random reader
 		iv := make([]byte, config.AEAD().Mode().IvLength())
@@ -270,7 +315,17 @@ func SerializeSymmetricKeyEncryptedReuseKey(w io.Writer, sessionKey []byte, pass
 	return
 }
 
-func getEncryptedKeyAeadInstance(c CipherFunction, mode AEADMode, inputKey, associatedData []byte) (aead cipher.AEAD) {
-	blockCipher := c.new(inputKey)
+func getEncryptedKeyAeadInstance(c CipherFunction, mode AEADMode, inputKey, associatedData []byte, version int) (aead cipher.AEAD) {
+	var blockCipher cipher.Block
+	if version > 5 {
+		hkdfReader := hkdf.New(sha256.New, inputKey, []byte{}, associatedData)
+
+		encryptionKey := make([]byte, c.KeySize())
+		_, _ = readFull(hkdfReader, encryptionKey)
+
+		blockCipher = c.new(encryptionKey)
+	} else {
+		blockCipher = c.new(inputKey)
+	}
 	return mode.new(blockCipher)
 }

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/symmetrically_encrypted.go

@@ -74,6 +74,10 @@ func (se *SymmetricallyEncrypted) Decrypt(c CipherFunction, key []byte) (io.Read
 // SerializeSymmetricallyEncrypted serializes a symmetrically encrypted packet
 // to w and returns a WriteCloser to which the to-be-encrypted packets can be
 // written.
+// If aeadSupported is set to true, SEIPDv2 is used with the indicated CipherSuite.
+// Otherwise, SEIPDv1 is used with the indicated CipherFunction.
+// Note: aeadSupported MUST match the value passed to SerializeEncryptedKeyAEAD
+// and/or SerializeSymmetricKeyEncryptedAEADReuseKey.
 // If config is nil, sensible defaults will be used.
 func SerializeSymmetricallyEncrypted(w io.Writer, c CipherFunction, aeadSupported bool, cipherSuite CipherSuite, key []byte, config *Config) (Contents io.WriteCloser, err error) {
 	writeCloser := noOpCloser{w}

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/symmetrically_encrypted_aead.go

@@ -7,7 +7,9 @@ package packet
 import (
 	"crypto/cipher"
 	"crypto/sha256"
+	"fmt"
 	"io"
+	"strconv"
 
 	"github.com/ProtonMail/go-crypto/openpgp/errors"
 	"golang.org/x/crypto/hkdf"
@@ -25,19 +27,19 @@ func (se *SymmetricallyEncrypted) parseAead(r io.Reader) error {
 	se.Cipher = CipherFunction(headerData[0])
 	// cipherFunc must have block size 16 to use AEAD
 	if se.Cipher.blockSize() != 16 {
-		return errors.UnsupportedError("invalid aead cipher: " + string(se.Cipher))
+		return errors.UnsupportedError("invalid aead cipher: " + strconv.Itoa(int(se.Cipher)))
 	}
 
 	// Mode
 	se.Mode = AEADMode(headerData[1])
 	if se.Mode.TagLength() == 0 {
-		return errors.UnsupportedError("unknown aead mode: " + string(se.Mode))
+		return errors.UnsupportedError("unknown aead mode: " + strconv.Itoa(int(se.Mode)))
 	}
 
 	// Chunk size
 	se.ChunkSizeByte = headerData[2]
 	if se.ChunkSizeByte > 16 {
-		return errors.UnsupportedError("invalid aead chunk size byte: " + string(se.ChunkSizeByte))
+		return errors.UnsupportedError("invalid aead chunk size byte: " + strconv.Itoa(int(se.ChunkSizeByte)))
 	}
 
 	// Salt
@@ -62,8 +64,11 @@ func (se *SymmetricallyEncrypted) associatedData() []byte {
 // decryptAead decrypts a V2 SEIPD packet (AEAD) as specified in
 // https://www.ietf.org/archive/id/draft-ietf-openpgp-crypto-refresh-07.html#section-5.13.2
 func (se *SymmetricallyEncrypted) decryptAead(inputKey []byte) (io.ReadCloser, error) {
-	aead, nonce := getSymmetricallyEncryptedAeadInstance(se.Cipher, se.Mode, inputKey, se.Salt[:], se.associatedData())
+	if se.Cipher.KeySize() != len(inputKey) {
+		return nil, errors.StructuralError(fmt.Sprintf("invalid session key length for cipher: got %d bytes, but expected %d bytes", len(inputKey), se.Cipher.KeySize()))
+	}
 
+	aead, nonce := getSymmetricallyEncryptedAeadInstance(se.Cipher, se.Mode, inputKey, se.Salt[:], se.associatedData())
 	// Carry the first tagLen bytes
 	tagLen := se.Mode.TagLength()
 	peekedBytes := make([]byte, tagLen)
@@ -115,7 +120,7 @@ func serializeSymmetricallyEncryptedAead(ciphertext io.WriteCloser, cipherSuite
 
 	// Random salt
 	salt := make([]byte, aeadSaltSize)
-	if _, err := rand.Read(salt); err != nil {
+	if _, err := io.ReadFull(rand, salt); err != nil {
 		return nil, err
 	}
 

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/symmetrically_encrypted_mdc.go

@@ -148,7 +148,7 @@ const mdcPacketTagByte = byte(0x80) | 0x40 | 19
 
 func (ser *seMDCReader) Close() error {
 	if ser.error {
-		return errors.ErrMDCMissing
+		return errors.ErrMDCHashMismatch
 	}
 
 	for !ser.eof {
@@ -159,7 +159,7 @@ func (ser *seMDCReader) Close() error {
 			break
 		}
 		if err != nil {
-			return errors.ErrMDCMissing
+			return errors.ErrMDCHashMismatch
 		}
 	}
 
@@ -172,7 +172,7 @@ func (ser *seMDCReader) Close() error {
 	// The hash already includes the MDC header, but we still check its value
 	// to confirm encryption correctness
 	if ser.trailer[0] != mdcPacketTagByte || ser.trailer[1] != sha1.Size {
-		return errors.ErrMDCMissing
+		return errors.ErrMDCHashMismatch
 	}
 	return nil
 }
@@ -237,9 +237,9 @@ func serializeSymmetricallyEncryptedMdc(ciphertext io.WriteCloser, c CipherFunct
 	block := c.new(key)
 	blockSize := block.BlockSize()
 	iv := make([]byte, blockSize)
-	_, err = config.Random().Read(iv)
+	_, err = io.ReadFull(config.Random(), iv)
 	if err != nil {
-		return
+		return nil, err
 	}
 	s, prefix := NewOCFBEncrypter(block, iv, OCFBNoResync)
 	_, err = ciphertext.Write(prefix)

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/userattribute.go

@@ -9,7 +9,6 @@ import (
 	"image"
 	"image/jpeg"
 	"io"
-	"io/ioutil"
 )
 
 const UserAttrImageSubpacket = 1
@@ -63,7 +62,7 @@ func NewUserAttribute(contents ...*OpaqueSubpacket) *UserAttribute {
 
 func (uat *UserAttribute) parse(r io.Reader) (err error) {
 	// RFC 4880, section 5.13
-	b, err := ioutil.ReadAll(r)
+	b, err := io.ReadAll(r)
 	if err != nil {
 		return
 	}

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/userid.go

@@ -6,7 +6,6 @@ package packet
 
 import (
 	"io"
-	"io/ioutil"
 	"strings"
 )
 
@@ -66,7 +65,7 @@ func NewUserId(name, comment, email string) *UserId {
 
 func (uid *UserId) parse(r io.Reader) (err error) {
 	// RFC 4880, section 5.11
-	b, err := ioutil.ReadAll(r)
+	b, err := io.ReadAll(r)
 	if err != nil {
 		return
 	}