diff options
Diffstat (limited to 'p2p')
| -rw-r--r-- | p2p/crypto.go | 51 |
1 files changed, 29 insertions, 22 deletions
diff --git a/p2p/crypto.go b/p2p/crypto.go index 6e3f360d9..643bd431e 100644 --- a/p2p/crypto.go +++ b/p2p/crypto.go @@ -17,7 +17,7 @@ var ( sigLen int = 65 // elliptic S256 keyLen int = 32 // ECDSA msgLen int = sigLen + 3*keyLen + 1 // 162 - resLen int = 65 + resLen int = 65 // ) // aesSecret, macSecret, egressMac, ingress @@ -133,7 +133,7 @@ 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, sharedSecret []byte, remotePubKey *ecdsa.PublicKey) (authResp []byte, respNonce []byte, initNonce []byte, remoteRandomPubKey *ecdsa.PublicKey, err error) { +func (self *cryptoId) verifyAuth(auth, sessionToken []byte, remotePubKey *ecdsa.PublicKey) (authResp []byte, respNonce []byte, initNonce []byte, remoteRandomPubKey *ecdsa.PublicKey, 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, @@ -141,50 +141,57 @@ func (self *cryptoId) verifyAuth(auth, sharedSecret []byte, remotePubKey *ecdsa. if msg, err = crypto.Decrypt(self.prvKey, auth); err != nil { return } + fmt.Printf("\nplaintext message retrieved: %v %x\n", len(msg), msg) - // var remoteNonce []byte = msg[msgLen-skLen-1 : msgLen-1] + var tokenFlag byte + 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 + // generate shared key from prv and remote pubkey + if sessionToken, err = ecies.ImportECDSA(self.prvKey).GenerateShared(ecies.ImportECDSAPublic(remotePubKey), sskLen, sskLen); err != nil { + return + } + fmt.Printf("secret generated: %v %x", len(sessionToken), sessionToken) + // tokenFlag = 0x00 // redundant + } else { + // for known peers, we use stored token from the previous session + tokenFlag = 0x01 + } + + // the initiator nonce is read off the end of the message initNonce = msg[msgLen-keyLen-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 - var signedMsg = Xor(sharedSecret, initNonce) + // we can now reconstruct the signed message and recover the peers pubkey + var signedMsg = Xor(sessionToken, initNonce) var remoteRandomPubKeyDER []byte if remoteRandomPubKeyDER, err = secp256k1.RecoverPubkey(signedMsg, msg[:sigLen]); err != nil { return } + // convert to ECDSA standard remoteRandomPubKey = crypto.ToECDSAPub(remoteRandomPubKeyDER) if remoteRandomPubKey == nil { err = fmt.Errorf("invalid remote public key") return } - var resp = make([]byte, 2*keyLen+1) - // generate sskLen long nonce - respNonce = msg[msgLen-keyLen-1 : msgLen-1] + // now we find ourselves a long task too, fill it random + var resp = make([]byte, resLen) + // generate keyLen long nonce + respNonce = msg[resLen-keyLen-1 : msgLen-1] if _, err = rand.Read(respNonce); err != nil { return } - // generate random keypair + // generate random keypair for session var ecdsaRandomPrvKey *ecdsa.PrivateKey if ecdsaRandomPrvKey, err = crypto.GenerateKey(); err != nil { return } - // var ecdsaRandomPubKey *ecdsa.PublicKey - // ecdsaRandomPubKey= &ecdsaRandomPrvKey.PublicKey - - // message + // responder auth message // E(remote-pubk, ecdhe-random-pubk || nonce || 0x0) copy(resp[:keyLen], crypto.FromECDSAPub(&ecdsaRandomPrvKey.PublicKey)) - // pubkey copied to the correct segment. - copy(resp[keyLen:2*keyLen], self.pubKeyDER) // nonce is already in the slice - // stick tokenFlag byte to the end - var tokenFlag byte - if sharedSecret == nil { - } else { - // for known peers, we use stored token from the previous session - tokenFlag = 0x01 - } - resp[resLen] = tokenFlag + resp[resLen-1] = tokenFlag // encrypt using remote-pubk // auth = eciesEncrypt(remote-pubk, msg) |