diff options
Diffstat (limited to 'vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/openpgp/packet/public_key.go')
| -rw-r--r-- | vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/openpgp/packet/public_key.go | 748 |
1 files changed, 748 insertions, 0 deletions
diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/openpgp/packet/public_key.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/openpgp/packet/public_key.go new file mode 100644 index 000000000..ead26233d --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/openpgp/packet/public_key.go @@ -0,0 +1,748 @@ +// Copyright 2011 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 ( + "bytes" + "crypto" + "crypto/dsa" + "crypto/ecdsa" + "crypto/elliptic" + "crypto/rsa" + "crypto/sha1" + _ "crypto/sha256" + _ "crypto/sha512" + "encoding/binary" + "fmt" + "hash" + "io" + "math/big" + "strconv" + "time" + + "golang.org/x/crypto/openpgp/elgamal" + "golang.org/x/crypto/openpgp/errors" +) + +var ( + // NIST curve P-256 + oidCurveP256 []byte = []byte{0x2A, 0x86, 0x48, 0xCE, 0x3D, 0x03, 0x01, 0x07} + // NIST curve P-384 + oidCurveP384 []byte = []byte{0x2B, 0x81, 0x04, 0x00, 0x22} + // NIST curve P-521 + oidCurveP521 []byte = []byte{0x2B, 0x81, 0x04, 0x00, 0x23} +) + +const maxOIDLength = 8 + +// ecdsaKey stores the algorithm-specific fields for ECDSA keys. +// as defined in RFC 6637, Section 9. +type ecdsaKey struct { + // oid contains the OID byte sequence identifying the elliptic curve used + oid []byte + // p contains the elliptic curve point that represents the public key + p parsedMPI +} + +// parseOID reads the OID for the curve as defined in RFC 6637, Section 9. +func parseOID(r io.Reader) (oid []byte, err error) { + buf := make([]byte, maxOIDLength) + if _, err = readFull(r, buf[:1]); err != nil { + return + } + oidLen := buf[0] + if int(oidLen) > len(buf) { + err = errors.UnsupportedError("invalid oid length: " + strconv.Itoa(int(oidLen))) + return + } + oid = buf[:oidLen] + _, err = readFull(r, oid) + return +} + +func (f *ecdsaKey) parse(r io.Reader) (err error) { + if f.oid, err = parseOID(r); err != nil { + return err + } + f.p.bytes, f.p.bitLength, err = readMPI(r) + return +} + +func (f *ecdsaKey) serialize(w io.Writer) (err error) { + buf := make([]byte, maxOIDLength+1) + buf[0] = byte(len(f.oid)) + copy(buf[1:], f.oid) + if _, err = w.Write(buf[:len(f.oid)+1]); err != nil { + return + } + return writeMPIs(w, f.p) +} + +func (f *ecdsaKey) newECDSA() (*ecdsa.PublicKey, error) { + var c elliptic.Curve + if bytes.Equal(f.oid, oidCurveP256) { + c = elliptic.P256() + } else if bytes.Equal(f.oid, oidCurveP384) { + c = elliptic.P384() + } else if bytes.Equal(f.oid, oidCurveP521) { + c = elliptic.P521() + } else { + return nil, errors.UnsupportedError(fmt.Sprintf("unsupported oid: %x", f.oid)) + } + x, y := elliptic.Unmarshal(c, f.p.bytes) + if x == nil { + return nil, errors.UnsupportedError("failed to parse EC point") + } + return &ecdsa.PublicKey{Curve: c, X: x, Y: y}, nil +} + +func (f *ecdsaKey) byteLen() int { + return 1 + len(f.oid) + 2 + len(f.p.bytes) +} + +type kdfHashFunction byte +type kdfAlgorithm byte + +// ecdhKdf stores key derivation function parameters +// used for ECDH encryption. See RFC 6637, Section 9. +type ecdhKdf struct { + KdfHash kdfHashFunction + KdfAlgo kdfAlgorithm +} + +func (f *ecdhKdf) parse(r io.Reader) (err error) { + buf := make([]byte, 1) + if _, err = readFull(r, buf); err != nil { + return + } + kdfLen := int(buf[0]) + if kdfLen < 3 { + return errors.UnsupportedError("Unsupported ECDH KDF length: " + strconv.Itoa(kdfLen)) + } + buf = make([]byte, kdfLen) + if _, err = readFull(r, buf); err != nil { + return + } + reserved := int(buf[0]) + f.KdfHash = kdfHashFunction(buf[1]) + f.KdfAlgo = kdfAlgorithm(buf[2]) + if reserved != 0x01 { + return errors.UnsupportedError("Unsupported KDF reserved field: " + strconv.Itoa(reserved)) + } + return +} + +func (f *ecdhKdf) serialize(w io.Writer) (err error) { + buf := make([]byte, 4) + // See RFC 6637, Section 9, Algorithm-Specific Fields for ECDH keys. + buf[0] = byte(0x03) // Length of the following fields + buf[1] = byte(0x01) // Reserved for future extensions, must be 1 for now + buf[2] = byte(f.KdfHash) + buf[3] = byte(f.KdfAlgo) + _, err = w.Write(buf[:]) + return +} + +func (f *ecdhKdf) byteLen() int { + return 4 +} + +// PublicKey represents an OpenPGP public key. See RFC 4880, section 5.5.2. +type PublicKey struct { + CreationTime time.Time + PubKeyAlgo PublicKeyAlgorithm + PublicKey interface{} // *rsa.PublicKey, *dsa.PublicKey or *ecdsa.PublicKey + Fingerprint [20]byte + KeyId uint64 + IsSubkey bool + + n, e, p, q, g, y parsedMPI + + // RFC 6637 fields + ec *ecdsaKey + ecdh *ecdhKdf +} + +// signingKey provides a convenient abstraction over signature verification +// for v3 and v4 public keys. +type signingKey interface { + SerializeSignaturePrefix(io.Writer) + serializeWithoutHeaders(io.Writer) error +} + +func fromBig(n *big.Int) parsedMPI { + return parsedMPI{ + bytes: n.Bytes(), + bitLength: uint16(n.BitLen()), + } +} + +// NewRSAPublicKey returns a PublicKey that wraps the given rsa.PublicKey. +func NewRSAPublicKey(creationTime time.Time, pub *rsa.PublicKey) *PublicKey { + pk := &PublicKey{ + CreationTime: creationTime, + PubKeyAlgo: PubKeyAlgoRSA, + PublicKey: pub, + n: fromBig(pub.N), + e: fromBig(big.NewInt(int64(pub.E))), + } + + pk.setFingerPrintAndKeyId() + return pk +} + +// NewDSAPublicKey returns a PublicKey that wraps the given dsa.PublicKey. +func NewDSAPublicKey(creationTime time.Time, pub *dsa.PublicKey) *PublicKey { + pk := &PublicKey{ + CreationTime: creationTime, + PubKeyAlgo: PubKeyAlgoDSA, + PublicKey: pub, + p: fromBig(pub.P), + q: fromBig(pub.Q), + g: fromBig(pub.G), + y: fromBig(pub.Y), + } + + pk.setFingerPrintAndKeyId() + return pk +} + +// NewElGamalPublicKey returns a PublicKey that wraps the given elgamal.PublicKey. +func NewElGamalPublicKey(creationTime time.Time, pub *elgamal.PublicKey) *PublicKey { + pk := &PublicKey{ + CreationTime: creationTime, + PubKeyAlgo: PubKeyAlgoElGamal, + PublicKey: pub, + p: fromBig(pub.P), + g: fromBig(pub.G), + y: fromBig(pub.Y), + } + + pk.setFingerPrintAndKeyId() + return pk +} + +func NewECDSAPublicKey(creationTime time.Time, pub *ecdsa.PublicKey) *PublicKey { + pk := &PublicKey{ + CreationTime: creationTime, + PubKeyAlgo: PubKeyAlgoECDSA, + PublicKey: pub, + ec: new(ecdsaKey), + } + + switch pub.Curve { + case elliptic.P256(): + pk.ec.oid = oidCurveP256 + case elliptic.P384(): + pk.ec.oid = oidCurveP384 + case elliptic.P521(): + pk.ec.oid = oidCurveP521 + default: + panic("unknown elliptic curve") + } + + pk.ec.p.bytes = elliptic.Marshal(pub.Curve, pub.X, pub.Y) + pk.ec.p.bitLength = uint16(8 * len(pk.ec.p.bytes)) + + pk.setFingerPrintAndKeyId() + return pk +} + +func (pk *PublicKey) parse(r io.Reader) (err error) { + // RFC 4880, section 5.5.2 + var buf [6]byte + _, err = readFull(r, buf[:]) + if err != nil { + return + } + if buf[0] != 4 { + 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.PubKeyAlgo = PublicKeyAlgorithm(buf[5]) + switch pk.PubKeyAlgo { + case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly: + err = pk.parseRSA(r) + case PubKeyAlgoDSA: + err = pk.parseDSA(r) + case PubKeyAlgoElGamal: + err = pk.parseElGamal(r) + case PubKeyAlgoECDSA: + pk.ec = new(ecdsaKey) + if err = pk.ec.parse(r); err != nil { + return err + } + pk.PublicKey, err = pk.ec.newECDSA() + case PubKeyAlgoECDH: + pk.ec = new(ecdsaKey) + if err = pk.ec.parse(r); err != nil { + return + } + pk.ecdh = new(ecdhKdf) + if err = pk.ecdh.parse(r); err != nil { + return + } + // The ECDH key is stored in an ecdsa.PublicKey for convenience. + pk.PublicKey, err = pk.ec.newECDSA() + default: + err = errors.UnsupportedError("public key type: " + strconv.Itoa(int(pk.PubKeyAlgo))) + } + if err != nil { + return + } + + pk.setFingerPrintAndKeyId() + return +} + +func (pk *PublicKey) setFingerPrintAndKeyId() { + // RFC 4880, section 12.2 + fingerPrint := sha1.New() + pk.SerializeSignaturePrefix(fingerPrint) + pk.serializeWithoutHeaders(fingerPrint) + copy(pk.Fingerprint[:], fingerPrint.Sum(nil)) + pk.KeyId = binary.BigEndian.Uint64(pk.Fingerprint[12:20]) +} + +// 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) { + pk.n.bytes, pk.n.bitLength, err = readMPI(r) + if err != nil { + return + } + pk.e.bytes, pk.e.bitLength, err = readMPI(r) + if err != nil { + return + } + + if len(pk.e.bytes) > 3 { + err = errors.UnsupportedError("large public exponent") + return + } + rsa := &rsa.PublicKey{ + N: new(big.Int).SetBytes(pk.n.bytes), + E: 0, + } + for i := 0; i < len(pk.e.bytes); i++ { + rsa.E <<= 8 + rsa.E |= int(pk.e.bytes[i]) + } + pk.PublicKey = rsa + return +} + +// parseDSA parses DSA public key material from the given Reader. See RFC 4880, +// section 5.5.2. +func (pk *PublicKey) parseDSA(r io.Reader) (err error) { + pk.p.bytes, pk.p.bitLength, err = readMPI(r) + if err != nil { + return + } + pk.q.bytes, pk.q.bitLength, err = readMPI(r) + if err != nil { + return + } + pk.g.bytes, pk.g.bitLength, err = readMPI(r) + if err != nil { + return + } + pk.y.bytes, pk.y.bitLength, err = readMPI(r) + if err != nil { + return + } + + dsa := new(dsa.PublicKey) + dsa.P = new(big.Int).SetBytes(pk.p.bytes) + dsa.Q = new(big.Int).SetBytes(pk.q.bytes) + dsa.G = new(big.Int).SetBytes(pk.g.bytes) + dsa.Y = new(big.Int).SetBytes(pk.y.bytes) + pk.PublicKey = dsa + return +} + +// parseElGamal parses ElGamal public key material from the given Reader. See +// RFC 4880, section 5.5.2. +func (pk *PublicKey) parseElGamal(r io.Reader) (err error) { + pk.p.bytes, pk.p.bitLength, err = readMPI(r) + if err != nil { + return + } + pk.g.bytes, pk.g.bitLength, err = readMPI(r) + if err != nil { + return + } + pk.y.bytes, pk.y.bitLength, err = readMPI(r) + if err != nil { + return + } + + elgamal := new(elgamal.PublicKey) + elgamal.P = new(big.Int).SetBytes(pk.p.bytes) + elgamal.G = new(big.Int).SetBytes(pk.g.bytes) + elgamal.Y = new(big.Int).SetBytes(pk.y.bytes) + pk.PublicKey = elgamal + 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 *PublicKey) SerializeSignaturePrefix(h 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)) + case PubKeyAlgoDSA: + pLength += 2 + uint16(len(pk.p.bytes)) + pLength += 2 + uint16(len(pk.q.bytes)) + pLength += 2 + uint16(len(pk.g.bytes)) + pLength += 2 + uint16(len(pk.y.bytes)) + case PubKeyAlgoElGamal: + pLength += 2 + uint16(len(pk.p.bytes)) + pLength += 2 + uint16(len(pk.g.bytes)) + pLength += 2 + uint16(len(pk.y.bytes)) + case PubKeyAlgoECDSA: + pLength += uint16(pk.ec.byteLen()) + case PubKeyAlgoECDH: + pLength += uint16(pk.ec.byteLen()) + pLength += uint16(pk.ecdh.byteLen()) + default: + panic("unknown public key algorithm") + } + pLength += 6 + h.Write([]byte{0x99, byte(pLength >> 8), byte(pLength)}) + return +} + +func (pk *PublicKey) Serialize(w io.Writer) (err error) { + length := 6 // 6 byte header + + switch pk.PubKeyAlgo { + case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly: + length += 2 + len(pk.n.bytes) + length += 2 + len(pk.e.bytes) + case PubKeyAlgoDSA: + length += 2 + len(pk.p.bytes) + length += 2 + len(pk.q.bytes) + length += 2 + len(pk.g.bytes) + length += 2 + len(pk.y.bytes) + case PubKeyAlgoElGamal: + length += 2 + len(pk.p.bytes) + length += 2 + len(pk.g.bytes) + length += 2 + len(pk.y.bytes) + case PubKeyAlgoECDSA: + length += pk.ec.byteLen() + case PubKeyAlgoECDH: + length += pk.ec.byteLen() + length += pk.ecdh.byteLen() + default: + panic("unknown public key algorithm") + } + + packetType := packetTypePublicKey + if pk.IsSubkey { + packetType = packetTypePublicSubkey + } + err = serializeHeader(w, packetType, length) + if 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 *PublicKey) serializeWithoutHeaders(w io.Writer) (err error) { + var buf [6]byte + buf[0] = 4 + t := uint32(pk.CreationTime.Unix()) + buf[1] = byte(t >> 24) + buf[2] = byte(t >> 16) + buf[3] = byte(t >> 8) + buf[4] = byte(t) + buf[5] = byte(pk.PubKeyAlgo) + + _, err = w.Write(buf[:]) + if err != nil { + return + } + + switch pk.PubKeyAlgo { + case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly: + return writeMPIs(w, pk.n, pk.e) + case PubKeyAlgoDSA: + return writeMPIs(w, pk.p, pk.q, pk.g, pk.y) + case PubKeyAlgoElGamal: + return writeMPIs(w, pk.p, pk.g, pk.y) + case PubKeyAlgoECDSA: + return pk.ec.serialize(w) + case PubKeyAlgoECDH: + if err = pk.ec.serialize(w); err != nil { + return + } + return pk.ecdh.serialize(w) + } + return errors.InvalidArgumentError("bad public-key algorithm") +} + +// CanSign returns true iff this public key can generate signatures +func (pk *PublicKey) CanSign() bool { + return pk.PubKeyAlgo != PubKeyAlgoRSAEncryptOnly && pk.PubKeyAlgo != PubKeyAlgoElGamal +} + +// 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) { + if !pk.CanSign() { + return errors.InvalidArgumentError("public key cannot generate signatures") + } + + 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") + } + + if pk.PubKeyAlgo != sig.PubKeyAlgo { + return errors.InvalidArgumentError("public key and signature use different algorithms") + } + + switch pk.PubKeyAlgo { + case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly: + rsaPublicKey, _ := pk.PublicKey.(*rsa.PublicKey) + err = rsa.VerifyPKCS1v15(rsaPublicKey, sig.Hash, hashBytes, sig.RSASignature.bytes) + if err != nil { + return errors.SignatureError("RSA verification failure") + } + return nil + case PubKeyAlgoDSA: + dsaPublicKey, _ := pk.PublicKey.(*dsa.PublicKey) + // Need to truncate hashBytes to match FIPS 186-3 section 4.6. + subgroupSize := (dsaPublicKey.Q.BitLen() + 7) / 8 + if len(hashBytes) > subgroupSize { + hashBytes = hashBytes[:subgroupSize] + } + if !dsa.Verify(dsaPublicKey, hashBytes, new(big.Int).SetBytes(sig.DSASigR.bytes), new(big.Int).SetBytes(sig.DSASigS.bytes)) { + return errors.SignatureError("DSA verification failure") + } + return nil + case PubKeyAlgoECDSA: + ecdsaPublicKey := pk.PublicKey.(*ecdsa.PublicKey) + if !ecdsa.Verify(ecdsaPublicKey, hashBytes, new(big.Int).SetBytes(sig.ECDSASigR.bytes), new(big.Int).SetBytes(sig.ECDSASigS.bytes)) { + return errors.SignatureError("ECDSA verification failure") + } + return nil + default: + return errors.SignatureError("Unsupported public key algorithm used in signature") + } +} + +// 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 *PublicKey) 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: + rsaPublicKey := pk.PublicKey.(*rsa.PublicKey) + if err = rsa.VerifyPKCS1v15(rsaPublicKey, sig.Hash, hashBytes, sig.RSASignature.bytes); err != nil { + return errors.SignatureError("RSA verification failure") + } + return + case PubKeyAlgoDSA: + dsaPublicKey := pk.PublicKey.(*dsa.PublicKey) + // Need to truncate hashBytes to match FIPS 186-3 section 4.6. + subgroupSize := (dsaPublicKey.Q.BitLen() + 7) / 8 + if len(hashBytes) > subgroupSize { + hashBytes = hashBytes[:subgroupSize] + } + if !dsa.Verify(dsaPublicKey, hashBytes, new(big.Int).SetBytes(sig.DSASigR.bytes), new(big.Int).SetBytes(sig.DSASigS.bytes)) { + return errors.SignatureError("DSA verification failure") + } + return nil + default: + panic("shouldn't happen") + } +} + +// 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() + + // RFC 4880, section 5.2.4 + pk.SerializeSignaturePrefix(h) + pk.serializeWithoutHeaders(h) + signed.SerializeSignaturePrefix(h) + signed.serializeWithoutHeaders(h) + return +} + +// 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) + if err != nil { + return err + } + if err = pk.VerifySignature(h, sig); err != nil { + return err + } + + if sig.FlagSign { + // Signing subkeys must be cross-signed. See + // https://www.gnupg.org/faq/subkey-cross-certify.html. + if sig.EmbeddedSignature == nil { + return errors.StructuralError("signing subkey is missing cross-signature") + } + // 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 { + return errors.StructuralError("error while hashing for cross-signature: " + err.Error()) + } + if err := signed.VerifySignature(h, sig.EmbeddedSignature); err != nil { + return errors.StructuralError("error while verifying cross-signature: " + err.Error()) + } + } + + return nil +} + +func keyRevocationHash(pk signingKey, hashFunc crypto.Hash) (h hash.Hash, err error) { + if !hashFunc.Available() { + return nil, errors.UnsupportedError("hash function") + } + h = hashFunc.New() + + // RFC 4880, section 5.2.4 + pk.SerializeSignaturePrefix(h) + pk.serializeWithoutHeaders(h) + + return +} + +// 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) + if err != nil { + return err + } + return pk.VerifySignature(h, sig) +} + +// 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() + + // RFC 4880, section 5.2.4 + pk.SerializeSignaturePrefix(h) + pk.serializeWithoutHeaders(h) + + var buf [5]byte + buf[0] = 0xb4 + buf[1] = byte(len(id) >> 24) + buf[2] = byte(len(id) >> 16) + buf[3] = byte(len(id) >> 8) + buf[4] = byte(len(id)) + h.Write(buf[:]) + h.Write([]byte(id)) + + return +} + +// 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) + if err != nil { + return err + } + return pk.VerifySignature(h, sig) +} + +// VerifyUserIdSignatureV3 returns nil iff sig is a valid signature, made by this +// public key, that id is the identity of pub. +func (pk *PublicKey) VerifyUserIdSignatureV3(id string, pub *PublicKey, sig *SignatureV3) (err error) { + h, err := userIdSignatureV3Hash(id, pub, sig.Hash) + if err != nil { + return err + } + return pk.VerifySignatureV3(h, sig) +} + +// KeyIdString returns the public key's fingerprint in capital hex +// (e.g. "6C7EE1B8621CC013"). +func (pk *PublicKey) KeyIdString() string { + return fmt.Sprintf("%X", pk.Fingerprint[12:20]) +} + +// KeyIdShortString returns the short form of public key's fingerprint +// in capital hex, as shown by gpg --list-keys (e.g. "621CC013"). +func (pk *PublicKey) KeyIdShortString() string { + return fmt.Sprintf("%X", pk.Fingerprint[16:20]) +} + +// A parsedMPI is used to store the contents of a big integer, along with the +// bit length that was specified in the original input. This allows the MPI to +// be reserialized exactly. +type parsedMPI struct { + bytes []byte + bitLength uint16 +} + +// writeMPIs is a utility function for serializing several big integers to the +// given Writer. +func writeMPIs(w io.Writer, mpis ...parsedMPI) (err error) { + for _, mpi := range mpis { + err = writeMPI(w, mpi.bitLength, mpi.bytes) + if err != nil { + return + } + } + return +} + +// BitLength returns the bit length for the given public key. +func (pk *PublicKey) BitLength() (bitLength uint16, err error) { + switch pk.PubKeyAlgo { + case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly: + bitLength = pk.n.bitLength + case PubKeyAlgoDSA: + bitLength = pk.p.bitLength + case PubKeyAlgoElGamal: + bitLength = pk.p.bitLength + default: + err = errors.InvalidArgumentError("bad public-key algorithm") + } + return +} |