diff options
Diffstat (limited to 'src/pkg/crypto/openpgp/packet/public_key.go')
| -rw-r--r-- | src/pkg/crypto/openpgp/packet/public_key.go | 103 |
1 files changed, 84 insertions, 19 deletions
diff --git a/src/pkg/crypto/openpgp/packet/public_key.go b/src/pkg/crypto/openpgp/packet/public_key.go index cd4a9aebb..46d365b2a 100644 --- a/src/pkg/crypto/openpgp/packet/public_key.go +++ b/src/pkg/crypto/openpgp/packet/public_key.go @@ -30,6 +30,28 @@ type PublicKey struct { n, e, p, q, g, y parsedMPI } +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(creationTimeSecs uint32, pub *rsa.PublicKey, isSubkey bool) *PublicKey { + pk := &PublicKey{ + CreationTime: creationTimeSecs, + PubKeyAlgo: PubKeyAlgoRSA, + PublicKey: pub, + IsSubkey: isSubkey, + n: fromBig(pub.N), + e: fromBig(big.NewInt(int64(pub.E))), + } + + pk.setFingerPrintAndKeyId() + return pk +} + func (pk *PublicKey) parse(r io.Reader) (err os.Error) { // RFC 4880, section 5.5.2 var buf [6]byte @@ -54,14 +76,17 @@ func (pk *PublicKey) parse(r io.Reader) (err os.Error) { return } + pk.setFingerPrintAndKeyId() + return +} + +func (pk *PublicKey) setFingerPrintAndKeyId() { // RFC 4880, section 12.2 fingerPrint := sha1.New() pk.SerializeSignaturePrefix(fingerPrint) - pk.Serialize(fingerPrint) + pk.serializeWithoutHeaders(fingerPrint) copy(pk.Fingerprint[:], fingerPrint.Sum()) pk.KeyId = binary.BigEndian.Uint64(pk.Fingerprint[12:20]) - - return } // parseRSA parses RSA public key material from the given Reader. See RFC 4880, @@ -143,9 +168,30 @@ func (pk *PublicKey) SerializeSignaturePrefix(h hash.Hash) { return } -// Serialize marshals the PublicKey to w in the form of an OpenPGP public key -// packet, not including the packet header. func (pk *PublicKey) Serialize(w io.Writer) (err os.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) + } + + err = serializeHeader(w, packetTypePublicKey, 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 os.Error) { var buf [6]byte buf[0] = 4 buf[1] = byte(pk.CreationTime >> 24) @@ -211,34 +257,43 @@ func (pk *PublicKey) VerifySignature(signed hash.Hash, sig *Signature) (err os.E panic("unreachable") } -// VerifyKeySignature returns nil iff sig is a valid signature, make by this -// public key, of the public key in signed. -func (pk *PublicKey) VerifyKeySignature(signed *PublicKey, sig *Signature) (err os.Error) { - h := sig.Hash.New() +// 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 *PublicKey, sig *Signature) (h hash.Hash, err os.Error) { + h = sig.Hash.New() if h == nil { - return error.UnsupportedError("hash function") + return nil, error.UnsupportedError("hash function") } // RFC 4880, section 5.2.4 pk.SerializeSignaturePrefix(h) - pk.Serialize(h) + pk.serializeWithoutHeaders(h) signed.SerializeSignaturePrefix(h) - signed.Serialize(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) (err os.Error) { + h, err := keySignatureHash(pk, signed, sig) + if err != nil { + return err + } return pk.VerifySignature(h, sig) } -// VerifyUserIdSignature returns nil iff sig is a valid signature, make by this -// public key, of the given user id. -func (pk *PublicKey) VerifyUserIdSignature(id string, sig *Signature) (err os.Error) { - h := sig.Hash.New() +// 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, sig *Signature) (h hash.Hash, err os.Error) { + h = sig.Hash.New() if h == nil { - return error.UnsupportedError("hash function") + return nil, error.UnsupportedError("hash function") } // RFC 4880, section 5.2.4 pk.SerializeSignaturePrefix(h) - pk.Serialize(h) + pk.serializeWithoutHeaders(h) var buf [5]byte buf[0] = 0xb4 @@ -249,6 +304,16 @@ func (pk *PublicKey) VerifyUserIdSignature(id string, sig *Signature) (err os.Er h.Write(buf[:]) h.Write([]byte(id)) + return +} + +// VerifyUserIdSignature returns nil iff sig is a valid signature, made by this +// public key, of id. +func (pk *PublicKey) VerifyUserIdSignature(id string, sig *Signature) (err os.Error) { + h, err := userIdSignatureHash(id, pk, sig) + if err != nil { + return err + } return pk.VerifySignature(h, sig) } @@ -272,7 +337,7 @@ type parsedMPI struct { bitLength uint16 } -// writeMPIs is a utility function for serialising several big integers to the +// writeMPIs is a utility function for serializing several big integers to the // given Writer. func writeMPIs(w io.Writer, mpis ...parsedMPI) (err os.Error) { for _, mpi := range mpis { |