diff options
Diffstat (limited to 'p2p/crypto.go')
| -rw-r--r-- | p2p/crypto.go | 44 |
1 files changed, 23 insertions, 21 deletions
diff --git a/p2p/crypto.go b/p2p/crypto.go index f5307cd5a..361012743 100644 --- a/p2p/crypto.go +++ b/p2p/crypto.go @@ -7,20 +7,20 @@ import ( "io" "github.com/ethereum/go-ethereum/crypto" + "github.com/ethereum/go-ethereum/crypto/secp256k1" ethlogger "github.com/ethereum/go-ethereum/logger" "github.com/obscuren/ecies" - "github.com/obscuren/secp256k1-go" ) var clogger = ethlogger.NewLogger("CRYPTOID") -var ( +const ( sskLen int = 16 // ecies.MaxSharedKeyLength(pubKey) / 2 sigLen int = 65 // elliptic S256 pubLen int = 64 // 512 bit pubkey in uncompressed representation without format byte - keyLen int = 32 // ECDSA - msgLen int = 194 // sigLen + keyLen + pubLen + keyLen + 1 = 194 - resLen int = 97 // pubLen + keyLen + 1 + shaLen int = 32 // hash length (for nonce etc) + msgLen int = 194 // sigLen + shaLen + pubLen + shaLen + 1 = 194 + resLen int = 97 // pubLen + shaLen + 1 iHSLen int = 307 // size of the final ECIES payload sent as initiator's handshake rHSLen int = 210 // size of the final ECIES payload sent as receiver's handshake ) @@ -157,7 +157,7 @@ func (self *cryptoId) Run(conn io.ReadWriter, remotePubKeyS []byte, sessionToken } clogger.Debugf("receiver handshake (sent to %v):\n%v", hexkey(remotePubKeyS), hexkey(response)) } - return self.newSession(initNonce, recNonce, auth, randomPrivKey, remoteRandomPubKey) + return self.newSession(initiator, initNonce, recNonce, auth, randomPrivKey, remoteRandomPubKey) } /* @@ -198,7 +198,7 @@ func (self *cryptoId) startHandshake(remotePubKeyS, sessionToken []byte) (auth [ return } - var tokenFlag byte + var tokenFlag byte // = 0x00 if sessionToken == nil { // no session token found means we need to generate shared secret. // ecies shared secret is used as initial session token for new peers @@ -216,7 +216,7 @@ func (self *cryptoId) startHandshake(remotePubKeyS, sessionToken []byte) (auth [ // E(remote-pubk, S(ecdhe-random, token^nonce) || H(ecdhe-random-pubk) || pubk || nonce || 0x1) // allocate msgLen long message, var msg []byte = make([]byte, msgLen) - initNonce = msg[msgLen-keyLen-1 : msgLen-1] + initNonce = msg[msgLen-shaLen-1 : msgLen-1] if _, err = rand.Read(initNonce); err != nil { return } @@ -245,9 +245,9 @@ func (self *cryptoId) startHandshake(remotePubKeyS, sessionToken []byte) (auth [ if randomPubKey64, err = ExportPublicKey(&randomPrvKey.PublicKey); err != nil { return } - copy(msg[sigLen:sigLen+keyLen], crypto.Sha3(randomPubKey64)) + copy(msg[sigLen:sigLen+shaLen], crypto.Sha3(randomPubKey64)) // pubkey copied to the correct segment. - copy(msg[sigLen+keyLen:sigLen+keyLen+pubLen], self.pubKeyS) + copy(msg[sigLen+shaLen:sigLen+shaLen+pubLen], self.pubKeyS) // nonce is already in the slice // stick tokenFlag byte to the end msg[msgLen-1] = tokenFlag @@ -295,7 +295,7 @@ func (self *cryptoId) respondToHandshake(auth, remotePubKeyS, sessionToken []byt } // the initiator nonce is read off the end of the message - initNonce = msg[msgLen-keyLen-1 : msgLen-1] + initNonce = msg[msgLen-shaLen-1 : msgLen-1] // I prove that i own prv key (to derive shared secret, and read nonce off encrypted msg) and that I own shared secret // they prove they own the private key belonging to ecdhe-random-pubk // we can now reconstruct the signed message and recover the peers pubkey @@ -311,8 +311,8 @@ func (self *cryptoId) respondToHandshake(auth, remotePubKeyS, sessionToken []byt // now we find ourselves a long task too, fill it random var resp = make([]byte, resLen) - // generate keyLen long nonce - respNonce = resp[pubLen : pubLen+keyLen] + // generate shaLen long nonce + respNonce = resp[pubLen : pubLen+shaLen] if _, err = rand.Read(respNonce); err != nil { return } @@ -350,7 +350,7 @@ func (self *cryptoId) completeHandshake(auth []byte) (respNonce []byte, remoteRa return } - respNonce = msg[pubLen : pubLen+keyLen] + respNonce = msg[pubLen : pubLen+shaLen] var remoteRandomPubKeyS = msg[:pubLen] if remoteRandomPubKey, err = ImportPublicKey(remoteRandomPubKeyS); err != nil { return @@ -364,7 +364,7 @@ func (self *cryptoId) completeHandshake(auth []byte) (respNonce []byte, remoteRa /* newSession is called after the handshake is completed. The arguments are values negotiated in the handshake and the return value is a new session : a new session Token to be remembered for the next time we connect with this peer. And a MsgReadWriter that implements an encrypted and authenticated connection with key material obtained from the crypto handshake key exchange */ -func (self *cryptoId) newSession(initNonce, respNonce, auth []byte, privKey *ecdsa.PrivateKey, remoteRandomPubKey *ecdsa.PublicKey) (sessionToken []byte, rw *secretRW, err error) { +func (self *cryptoId) newSession(initiator bool, initNonce, respNonce, auth []byte, privKey *ecdsa.PrivateKey, remoteRandomPubKey *ecdsa.PublicKey) (sessionToken []byte, rw *secretRW, err error) { // 3) Now we can trust ecdhe-random-pubk to derive new keys //ecdhe-shared-secret = ecdh.agree(ecdhe-random, remote-ecdhe-random-pubk) var dhSharedSecret []byte @@ -382,12 +382,14 @@ func (self *cryptoId) newSession(initNonce, respNonce, auth []byte, privKey *ecd // mac-secret = crypto.Sha3(ecdhe-shared-secret || aes-secret) var macSecret = crypto.Sha3(append(dhSharedSecret, aesSecret...)) // # destroy ecdhe-shared-secret - // egress-mac = crypto.Sha3(mac-secret^nonce || auth) - var egressMac = crypto.Sha3(append(Xor(macSecret, respNonce), auth...)) - // # destroy nonce - // ingress-mac = crypto.Sha3(mac-secret^initiator-nonce || auth), - var ingressMac = crypto.Sha3(append(Xor(macSecret, initNonce), auth...)) - // # destroy remote-nonce + var egressMac, ingressMac []byte + if initiator { + egressMac = Xor(macSecret, respNonce) + ingressMac = Xor(macSecret, initNonce) + } else { + egressMac = Xor(macSecret, initNonce) + ingressMac = Xor(macSecret, respNonce) + } rw = &secretRW{ aesSecret: aesSecret, macSecret: macSecret, |