diff options
Diffstat (limited to 'p2p/crypto.go')
| -rw-r--r-- | p2p/crypto.go | 45 |
1 files changed, 29 insertions, 16 deletions
diff --git a/p2p/crypto.go b/p2p/crypto.go index 10c82d3a1..37c6e1fc9 100644 --- a/p2p/crypto.go +++ b/p2p/crypto.go @@ -53,10 +53,24 @@ func newCryptoId(id ClientIdentity) (self *cryptoId, err error) { return } -// initAuth is called by peer if it initiated the connection -func (self *cryptoId) initAuth(remotePubKeyDER, sessionToken []byte) (auth []byte, initNonce []byte, remotePubKey *ecdsa.PublicKey, err error) { +/* startHandshake is called by peer if it initiated the connection. + By protocol spec, the party who initiates the connection (initiator) will send an 'auth' packet +New: authInitiator -> E(remote-pubk, S(ecdhe-random, ecdh-shared-secret^nonce) || H(ecdhe-random-pubk) || pubk || nonce || 0x0) + authRecipient -> E(remote-pubk, ecdhe-random-pubk || nonce || 0x0) + +Known: authInitiator = E(remote-pubk, S(ecdhe-random, token^nonce) || H(ecdhe-random-pubk) || pubk || nonce || 0x1) + authRecipient = E(remote-pubk, ecdhe-random-pubk || nonce || 0x1) // token found + authRecipient = E(remote-pubk, ecdhe-random-pubk || nonce || 0x0) // token not found + +The caller provides the public key of the peer as conjuctured from lookup based on IP:port, given as user input or proven by signatures. The caller must have access to persistant information about the peers, and pass the previous session token as an argument to cryptoId. + +The handshake is the process by which the peers establish their connection for a session. + +*/ + +func (self *cryptoId) startHandshake(remotePubKeyDER, sessionToken []byte) (auth []byte, initNonce []byte, randomPrvKey *ecdsa.PrivateKey, randomPubKey *ecdsa.PublicKey, err error) { // session init, common to both parties - remotePubKey = crypto.ToECDSAPub(remotePubKeyDER) + remotePubKey := crypto.ToECDSAPub(remotePubKeyDER) if remotePubKey == nil { err = fmt.Errorf("invalid remote public key") return @@ -70,6 +84,7 @@ func (self *cryptoId) initAuth(remotePubKeyDER, sessionToken []byte) (auth []byt if sessionToken, err = ecies.ImportECDSA(self.prvKey).GenerateShared(ecies.ImportECDSAPublic(remotePubKey), sskLen, sskLen); err != nil { return } + // this will not stay here ;) fmt.Printf("secret generated: %v %x", len(sessionToken), sessionToken) // tokenFlag = 0x00 // redundant } else { @@ -93,15 +108,14 @@ func (self *cryptoId) initAuth(remotePubKeyDER, sessionToken []byte) (auth []byt var sharedSecret = Xor(sessionToken, initNonce) // generate random keypair to use for signing - var ecdsaRandomPrvKey *ecdsa.PrivateKey - if ecdsaRandomPrvKey, err = crypto.GenerateKey(); err != nil { + if randomPrvKey, err = crypto.GenerateKey(); err != nil { return } // sign shared secret (message known to both parties): shared-secret var signature []byte // signature = sign(ecdhe-random, shared-secret) // uses secp256k1.Sign - if signature, err = crypto.Sign(sharedSecret, ecdsaRandomPrvKey); err != nil { + if signature, err = crypto.Sign(sharedSecret, randomPrvKey); err != nil { return } fmt.Printf("signature generated: %v %x", len(signature), signature) @@ -110,7 +124,7 @@ func (self *cryptoId) initAuth(remotePubKeyDER, sessionToken []byte) (auth []byt // signed-shared-secret || H(ecdhe-random-pubk) || pubk || nonce || 0x0 copy(msg, signature) // copy signed-shared-secret // H(ecdhe-random-pubk) - copy(msg[sigLen:sigLen+keyLen], crypto.Sha3(crypto.FromECDSAPub(&ecdsaRandomPrvKey.PublicKey))) + copy(msg[sigLen:sigLen+keyLen], crypto.Sha3(crypto.FromECDSAPub(&randomPrvKey.PublicKey))) // pubkey copied to the correct segment. copy(msg[sigLen+keyLen:sigLen+2*keyLen], self.pubKeyDER) // nonce is already in the slice @@ -131,7 +145,7 @@ func (self *cryptoId) initAuth(remotePubKeyDER, sessionToken []byte) (auth []byt } // verifyAuth is called by peer if it accepted (but not initiated) the connection -func (self *cryptoId) verifyAuth(auth, sessionToken []byte, remotePubKey *ecdsa.PublicKey) (authResp []byte, respNonce []byte, initNonce []byte, remoteRandomPubKey *ecdsa.PublicKey, err error) { +func (self *cryptoId) respondToHandshake(auth, sessionToken []byte, remotePubKey *ecdsa.PublicKey) (authResp []byte, respNonce []byte, initNonce []byte, randomPrvKey *ecdsa.PrivateKey, err error) { var msg []byte fmt.Printf("encrypted message received: %v %x\n used pubkey: %x\n", len(auth), auth, crypto.FromECDSAPub(self.pubKey)) // they prove that msg is meant for me, @@ -167,7 +181,7 @@ func (self *cryptoId) verifyAuth(auth, sessionToken []byte, remotePubKey *ecdsa. return } // convert to ECDSA standard - remoteRandomPubKey = crypto.ToECDSAPub(remoteRandomPubKeyDER) + remoteRandomPubKey := crypto.ToECDSAPub(remoteRandomPubKeyDER) if remoteRandomPubKey == nil { err = fmt.Errorf("invalid remote public key") return @@ -181,13 +195,12 @@ func (self *cryptoId) verifyAuth(auth, sessionToken []byte, remotePubKey *ecdsa. return } // generate random keypair for session - var ecdsaRandomPrvKey *ecdsa.PrivateKey - if ecdsaRandomPrvKey, err = crypto.GenerateKey(); err != nil { + if randomPrvKey, err = crypto.GenerateKey(); err != nil { return } // responder auth message // E(remote-pubk, ecdhe-random-pubk || nonce || 0x0) - copy(resp[:keyLen], crypto.FromECDSAPub(&ecdsaRandomPrvKey.PublicKey)) + copy(resp[:keyLen], crypto.FromECDSAPub(&randomPrvKey.PublicKey)) // nonce is already in the slice resp[resLen-1] = tokenFlag @@ -200,7 +213,7 @@ func (self *cryptoId) verifyAuth(auth, sessionToken []byte, remotePubKey *ecdsa. return } -func (self *cryptoId) verifyAuthResp(auth []byte) (respNonce []byte, remoteRandomPubKey *ecdsa.PublicKey, tokenFlag bool, err error) { +func (self *cryptoId) completeHandshake(auth []byte) (respNonce []byte, remoteRandomPubKey *ecdsa.PublicKey, tokenFlag bool, err error) { var msg []byte // they prove that msg is meant for me, // I prove I possess private key if i can read it @@ -221,12 +234,12 @@ func (self *cryptoId) verifyAuthResp(auth []byte) (respNonce []byte, remoteRando return } -func (self *cryptoId) newSession(initNonce, respNonce, auth []byte, remoteRandomPubKey *ecdsa.PublicKey) (sessionToken []byte, rw *secretRW, err error) { +func (self *cryptoId) newSession(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 - dhSharedSecret, err = ecies.ImportECDSA(self.prvKey).GenerateShared(ecies.ImportECDSAPublic(remoteRandomPubKey), sskLen, sskLen) - if err != nil { + pubKey := ecies.ImportECDSAPublic(remoteRandomPubKey) + if dhSharedSecret, err = ecies.ImportECDSA(privKey).GenerateShared(pubKey, sskLen, sskLen); err != nil { return } // shared-secret = crypto.Sha3(ecdhe-shared-secret || crypto.Sha3(nonce || initiator-nonce)) |