1 files changed, 280 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/openpgp/packet/public_key_v3.go b/vendor/golang.org/x/crypto/openpgp/packet/public_key_v3.go
new file mode 100644
index 000000000..26337f5aa
--- /dev/null
+++ b/vendor/golang.org/x/crypto/openpgp/packet/public_key_v3.go
@@ -0,0 +1,280 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package packet
+
+import (
+	"crypto"
+	"crypto/md5"
+	"crypto/rsa"
+	"encoding/binary"
+	"fmt"
+	"hash"
+	"io"
+	"math/big"
+	"strconv"
+	"time"
+
+	"golang.org/x/crypto/openpgp/errors"
+)
+
+// PublicKeyV3 represents older, version 3 public keys. These keys are less secure and
+// should not be used for signing or encrypting. They are supported here only for
+// parsing version 3 key material and validating signatures.
+// See RFC 4880, section 5.5.2.
+type PublicKeyV3 struct {
+	CreationTime time.Time
+	DaysToExpire uint16
+	PubKeyAlgo   PublicKeyAlgorithm
+	PublicKey    *rsa.PublicKey
+	Fingerprint  [16]byte
+	KeyId        uint64
+	IsSubkey     bool
+
+	n, e parsedMPI
+}
+
+// newRSAPublicKeyV3 returns a PublicKey that wraps the given rsa.PublicKey.
+// Included here for testing purposes only. RFC 4880, section 5.5.2:
+// "an implementation MUST NOT generate a V3 key, but MAY accept it."
+func newRSAPublicKeyV3(creationTime time.Time, pub *rsa.PublicKey) *PublicKeyV3 {
+	pk := &PublicKeyV3{
+		CreationTime: creationTime,
+		PublicKey:    pub,
+		n:            fromBig(pub.N),
+		e:            fromBig(big.NewInt(int64(pub.E))),
+	}
+
+	pk.setFingerPrintAndKeyId()
+	return pk
+}
+
+func (pk *PublicKeyV3) parse(r io.Reader) (err error) {
+	// RFC 4880, section 5.5.2
+	var buf [8]byte
+	if _, err = readFull(r, buf[:]); err != nil {
+		return
+	}
+	if buf[0] < 2 || buf[0] > 3 {
+		return errors.UnsupportedError("public key version")
+	}
+	pk.CreationTime = time.Unix(int64(uint32(buf[1])<<24|uint32(buf[2])<<16|uint32(buf[3])<<8|uint32(buf[4])), 0)
+	pk.DaysToExpire = binary.BigEndian.Uint16(buf[5:7])
+	pk.PubKeyAlgo = PublicKeyAlgorithm(buf[7])
+	switch pk.PubKeyAlgo {
+	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
+		err = pk.parseRSA(r)
+	default:
+		err = errors.UnsupportedError("public key type: " + strconv.Itoa(int(pk.PubKeyAlgo)))
+	}
+	if err != nil {
+		return
+	}
+
+	pk.setFingerPrintAndKeyId()
+	return
+}
+
+func (pk *PublicKeyV3) setFingerPrintAndKeyId() {
+	// RFC 4880, section 12.2
+	fingerPrint := md5.New()
+	fingerPrint.Write(pk.n.bytes)
+	fingerPrint.Write(pk.e.bytes)
+	fingerPrint.Sum(pk.Fingerprint[:0])
+	pk.KeyId = binary.BigEndian.Uint64(pk.n.bytes[len(pk.n.bytes)-8:])
+}
+
+// parseRSA parses RSA public key material from the given Reader. See RFC 4880,
+// section 5.5.2.
+func (pk *PublicKeyV3) parseRSA(r io.Reader) (err error) {
+	if pk.n.bytes, pk.n.bitLength, err = readMPI(r); err != nil {
+		return
+	}
+	if pk.e.bytes, pk.e.bitLength, err = readMPI(r); err != nil {
+		return
+	}
+
+	// RFC 4880 Section 12.2 requires the low 8 bytes of the
+	// modulus to form the key id.
+	if len(pk.n.bytes) < 8 {
+		return errors.StructuralError("v3 public key modulus is too short")
+	}
+	if len(pk.e.bytes) > 3 {
+		err = errors.UnsupportedError("large public exponent")
+		return
+	}
+	rsa := &rsa.PublicKey{N: new(big.Int).SetBytes(pk.n.bytes)}
+	for i := 0; i < len(pk.e.bytes); i++ {
+		rsa.E <<= 8
+		rsa.E |= int(pk.e.bytes[i])
+	}
+	pk.PublicKey = rsa
+	return
+}
+
+// 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 *PublicKeyV3) SerializeSignaturePrefix(w io.Writer) {
+	var pLength uint16
+	switch pk.PubKeyAlgo {
+	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
+		pLength += 2 + uint16(len(pk.n.bytes))
+		pLength += 2 + uint16(len(pk.e.bytes))
+	default:
+		panic("unknown public key algorithm")
+	}
+	pLength += 6
+	w.Write([]byte{0x99, byte(pLength >> 8), byte(pLength)})
+	return
+}
+
+func (pk *PublicKeyV3) Serialize(w io.Writer) (err error) {
+	length := 8 // 8 byte header
+
+	switch pk.PubKeyAlgo {
+	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
+		length += 2 + len(pk.n.bytes)
+		length += 2 + len(pk.e.bytes)
+	default:
+		panic("unknown public key algorithm")
+	}
+
+	packetType := packetTypePublicKey
+	if pk.IsSubkey {
+		packetType = packetTypePublicSubkey
+	}
+	if err = serializeHeader(w, packetType, length); err != nil {
+		return
+	}
+	return pk.serializeWithoutHeaders(w)
+}
+
+// serializeWithoutHeaders marshals the PublicKey to w in the form of an
+// OpenPGP public key packet, not including the packet header.
+func (pk *PublicKeyV3) serializeWithoutHeaders(w io.Writer) (err error) {
+	var buf [8]byte
+	// Version 3
+	buf[0] = 3
+	// Creation time
+	t := uint32(pk.CreationTime.Unix())
+	buf[1] = byte(t >> 24)
+	buf[2] = byte(t >> 16)
+	buf[3] = byte(t >> 8)
+	buf[4] = byte(t)
+	// Days to expire
+	buf[5] = byte(pk.DaysToExpire >> 8)
+	buf[6] = byte(pk.DaysToExpire)
+	// Public key algorithm
+	buf[7] = byte(pk.PubKeyAlgo)
+
+	if _, err = w.Write(buf[:]); err != nil {
+		return
+	}
+
+	switch pk.PubKeyAlgo {
+	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
+		return writeMPIs(w, pk.n, pk.e)
+	}
+	return errors.InvalidArgumentError("bad public-key algorithm")
+}
+
+// CanSign returns true iff this public key can generate signatures
+func (pk *PublicKeyV3) CanSign() bool {
+	return pk.PubKeyAlgo != PubKeyAlgoRSAEncryptOnly
+}
+
+// VerifySignatureV3 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 *PublicKeyV3) VerifySignatureV3(signed hash.Hash, sig *SignatureV3) (err error) {
+	if !pk.CanSign() {
+		return errors.InvalidArgumentError("public key cannot generate signatures")
+	}
+
+	suffix := make([]byte, 5)
+	suffix[0] = byte(sig.SigType)
+	binary.BigEndian.PutUint32(suffix[1:], uint32(sig.CreationTime.Unix()))
+	signed.Write(suffix)
+	hashBytes := signed.Sum(nil)
+
+	if hashBytes[0] != sig.HashTag[0] || hashBytes[1] != sig.HashTag[1] {
+		return errors.SignatureError("hash tag doesn't match")
+	}
+
+	if pk.PubKeyAlgo != sig.PubKeyAlgo {
+		return errors.InvalidArgumentError("public key and signature use different algorithms")
+	}
+
+	switch pk.PubKeyAlgo {
+	case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly:
+		if err = rsa.VerifyPKCS1v15(pk.PublicKey, sig.Hash, hashBytes, sig.RSASignature.bytes); err != nil {
+			return errors.SignatureError("RSA verification failure")
+		}
+		return
+	default:
+		// V3 public keys only support RSA.
+		panic("shouldn't happen")
+	}
+	panic("unreachable")
+}
+
+// VerifyUserIdSignatureV3 returns nil iff sig is a valid signature, made by this
+// public key, that id is the identity of pub.
+func (pk *PublicKeyV3) VerifyUserIdSignatureV3(id string, pub *PublicKeyV3, sig *SignatureV3) (err error) {
+	h, err := userIdSignatureV3Hash(id, pk, sig.Hash)
+	if err != nil {
+		return err
+	}
+	return pk.VerifySignatureV3(h, sig)
+}
+
+// VerifyKeySignatureV3 returns nil iff sig is a valid signature, made by this
+// public key, of signed.
+func (pk *PublicKeyV3) VerifyKeySignatureV3(signed *PublicKeyV3, sig *SignatureV3) (err error) {
+	h, err := keySignatureHash(pk, signed, sig.Hash)
+	if err != nil {
+		return err
+	}
+	return pk.VerifySignatureV3(h, sig)
+}
+
+// userIdSignatureV3Hash returns a Hash of the message that needs to be signed
+// to assert that pk is a valid key for id.
+func userIdSignatureV3Hash(id string, pk signingKey, hfn crypto.Hash) (h hash.Hash, err error) {
+	if !hfn.Available() {
+		return nil, errors.UnsupportedError("hash function")
+	}
+	h = hfn.New()
+
+	// RFC 4880, section 5.2.4
+	pk.SerializeSignaturePrefix(h)
+	pk.serializeWithoutHeaders(h)
+
+	h.Write([]byte(id))
+
+	return
+}
+
+// KeyIdString returns the public key's fingerprint in capital hex
+// (e.g. "6C7EE1B8621CC013").
+func (pk *PublicKeyV3) KeyIdString() string {
+	return fmt.Sprintf("%X", pk.KeyId)
+}
+
+// KeyIdShortString returns the short form of public key's fingerprint
+// in capital hex, as shown by gpg --list-keys (e.g. "621CC013").
+func (pk *PublicKeyV3) KeyIdShortString() string {
+	return fmt.Sprintf("%X", pk.KeyId&0xFFFFFFFF)
+}
+
+// BitLength returns the bit length for the given public key.
+func (pk *PublicKeyV3) BitLength() (bitLength uint16, err error) {
+	switch pk.PubKeyAlgo {
+	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
+		bitLength = pk.n.bitLength
+	default:
+		err = errors.InvalidArgumentError("bad public-key algorithm")
+	}
+	return
+}