p2p: disable encryption handshake

The diff is a bit bigger than expected because the protocol handshake
logic has moved out of Peer. This is necessary because the protocol
handshake will have custom framing in the final protocol.

1 files changed, 0 insertions, 363 deletions

diff --git a/p2p/crypto.go b/p2p/crypto.go
deleted file mode 100644
index 7e4b43712..000000000
--- a/p2p/crypto.go
+++ /dev/null
@@ -1,363 +0,0 @@
-package p2p
-
-import (
-	// "binary"
-	"crypto/ecdsa"
-	"crypto/rand"
-	"fmt"
-	"io"
-
-	"github.com/ethereum/go-ethereum/crypto"
-	"github.com/ethereum/go-ethereum/crypto/ecies"
-	"github.com/ethereum/go-ethereum/crypto/secp256k1"
-	ethlogger "github.com/ethereum/go-ethereum/logger"
-	"github.com/ethereum/go-ethereum/p2p/discover"
-)
-
-var clogger = ethlogger.NewLogger("CRYPTOID")
-
-const (
-	sskLen = 16 // ecies.MaxSharedKeyLength(pubKey) / 2
-	sigLen = 65 // elliptic S256
-	pubLen = 64 // 512 bit pubkey in uncompressed representation without format byte
-	shaLen = 32 // hash length (for nonce etc)
-
-	authMsgLen  = sigLen + shaLen + pubLen + shaLen + 1
-	authRespLen = pubLen + shaLen + 1
-
-	eciesBytes = 65 + 16 + 32
-	iHSLen     = authMsgLen + eciesBytes  // size of the final ECIES payload sent as initiator's handshake
-	rHSLen     = authRespLen + eciesBytes // size of the final ECIES payload sent as receiver's handshake
-)
-
-type hexkey []byte
-
-func (self hexkey) String() string {
-	return fmt.Sprintf("(%d) %x", len(self), []byte(self))
-}
-
-func encHandshake(conn io.ReadWriter, prv *ecdsa.PrivateKey, dial *discover.Node) (
-	remoteID discover.NodeID,
-	sessionToken []byte,
-	err error,
-) {
-	if dial == nil {
-		var remotePubkey []byte
-		sessionToken, remotePubkey, err = inboundEncHandshake(conn, prv, nil)
-		copy(remoteID[:], remotePubkey)
-	} else {
-		remoteID = dial.ID
-		sessionToken, err = outboundEncHandshake(conn, prv, remoteID[:], nil)
-	}
-	return remoteID, sessionToken, err
-}
-
-// outboundEncHandshake negotiates a session token on conn.
-// it should be called on the dialing side of the connection.
-//
-// privateKey is the local client's private key
-// remotePublicKey is the remote peer's node ID
-// sessionToken is the token from a previous session with this node.
-func outboundEncHandshake(conn io.ReadWriter, prvKey *ecdsa.PrivateKey, remotePublicKey []byte, sessionToken []byte) (
-	newSessionToken []byte,
-	err error,
-) {
-	auth, initNonce, randomPrivKey, err := authMsg(prvKey, remotePublicKey, sessionToken)
-	if err != nil {
-		return nil, err
-	}
-	if sessionToken != nil {
-		clogger.Debugf("session-token: %v", hexkey(sessionToken))
-	}
-
-	clogger.Debugf("initiator-nonce: %v", hexkey(initNonce))
-	clogger.Debugf("initiator-random-private-key: %v", hexkey(crypto.FromECDSA(randomPrivKey)))
-	randomPublicKeyS, _ := exportPublicKey(&randomPrivKey.PublicKey)
-	clogger.Debugf("initiator-random-public-key: %v", hexkey(randomPublicKeyS))
-	if _, err = conn.Write(auth); err != nil {
-		return nil, err
-	}
-	clogger.Debugf("initiator handshake: %v", hexkey(auth))
-
-	response := make([]byte, rHSLen)
-	if _, err = io.ReadFull(conn, response); err != nil {
-		return nil, err
-	}
-	recNonce, remoteRandomPubKey, _, err := completeHandshake(response, prvKey)
-	if err != nil {
-		return nil, err
-	}
-
-	clogger.Debugf("receiver-nonce: %v", hexkey(recNonce))
-	remoteRandomPubKeyS, _ := exportPublicKey(remoteRandomPubKey)
-	clogger.Debugf("receiver-random-public-key: %v", hexkey(remoteRandomPubKeyS))
-	return newSession(initNonce, recNonce, randomPrivKey, remoteRandomPubKey)
-}
-
-// authMsg creates the initiator handshake.
-func authMsg(prvKey *ecdsa.PrivateKey, remotePubKeyS, sessionToken []byte) (
-	auth, initNonce []byte,
-	randomPrvKey *ecdsa.PrivateKey,
-	err error,
-) {
-	// session init, common to both parties
-	remotePubKey, err := importPublicKey(remotePubKeyS)
-	if err != nil {
-		return
-	}
-
-	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
-		// generate shared key from prv and remote pubkey
-		if sessionToken, err = ecies.ImportECDSA(prvKey).GenerateShared(ecies.ImportECDSAPublic(remotePubKey), sskLen, sskLen); err != nil {
-			return
-		}
-		// tokenFlag = 0x00 // redundant
-	} else {
-		// for known peers, we use stored token from the previous session
-		tokenFlag = 0x01
-	}
-
-	//E(remote-pubk, S(ecdhe-random, ecdh-shared-secret^nonce) || H(ecdhe-random-pubk) || pubk || nonce || 0x0)
-	// E(remote-pubk, S(ecdhe-random, token^nonce) || H(ecdhe-random-pubk) || pubk || nonce || 0x1)
-	// allocate msgLen long message,
-	var msg []byte = make([]byte, authMsgLen)
-	initNonce = msg[authMsgLen-shaLen-1 : authMsgLen-1]
-	if _, err = rand.Read(initNonce); err != nil {
-		return
-	}
-	// create known message
-	// ecdh-shared-secret^nonce for new peers
-	// token^nonce for old peers
-	var sharedSecret = xor(sessionToken, initNonce)
-
-	// generate random keypair to use for signing
-	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, randomPrvKey); err != nil {
-		return
-	}
-
-	// message
-	// signed-shared-secret || H(ecdhe-random-pubk) || pubk || nonce || 0x0
-	copy(msg, signature) // copy signed-shared-secret
-	// H(ecdhe-random-pubk)
-	var randomPubKey64 []byte
-	if randomPubKey64, err = exportPublicKey(&randomPrvKey.PublicKey); err != nil {
-		return
-	}
-	var pubKey64 []byte
-	if pubKey64, err = exportPublicKey(&prvKey.PublicKey); err != nil {
-		return
-	}
-	copy(msg[sigLen:sigLen+shaLen], crypto.Sha3(randomPubKey64))
-	// pubkey copied to the correct segment.
-	copy(msg[sigLen+shaLen:sigLen+shaLen+pubLen], pubKey64)
-	// nonce is already in the slice
-	// stick tokenFlag byte to the end
-	msg[authMsgLen-1] = tokenFlag
-
-	// encrypt using remote-pubk
-	// auth = eciesEncrypt(remote-pubk, msg)
-	if auth, err = crypto.Encrypt(remotePubKey, msg); err != nil {
-		return
-	}
-	return
-}
-
-// completeHandshake is called when the initiator receives an
-// authentication response (aka receiver handshake). It completes the
-// handshake by reading off parameters the remote peer provides needed
-// to set up the secure session.
-func completeHandshake(auth []byte, prvKey *ecdsa.PrivateKey) (
-	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
-	if msg, err = crypto.Decrypt(prvKey, auth); err != nil {
-		return
-	}
-
-	respNonce = msg[pubLen : pubLen+shaLen]
-	var remoteRandomPubKeyS = msg[:pubLen]
-	if remoteRandomPubKey, err = importPublicKey(remoteRandomPubKeyS); err != nil {
-		return
-	}
-	if msg[authRespLen-1] == 0x01 {
-		tokenFlag = true
-	}
-	return
-}
-
-// inboundEncHandshake negotiates a session token on conn.
-// it should be called on the listening side of the connection.
-//
-// privateKey is the local client's private key
-// sessionToken is the token from a previous session with this node.
-func inboundEncHandshake(conn io.ReadWriter, prvKey *ecdsa.PrivateKey, sessionToken []byte) (
-	token, remotePubKey []byte,
-	err error,
-) {
-	// we are listening connection. we are responders in the
-	// handshake. Extract info from the authentication. The initiator
-	// starts by sending us a handshake that we need to respond to. so
-	// we read auth message first, then respond.
-	auth := make([]byte, iHSLen)
-	if _, err := io.ReadFull(conn, auth); err != nil {
-		return nil, nil, err
-	}
-	response, recNonce, initNonce, remotePubKey, randomPrivKey, remoteRandomPubKey, err := authResp(auth, sessionToken, prvKey)
-	if err != nil {
-		return nil, nil, err
-	}
-	clogger.Debugf("receiver-nonce: %v", hexkey(recNonce))
-	clogger.Debugf("receiver-random-priv-key: %v", hexkey(crypto.FromECDSA(randomPrivKey)))
-	if _, err = conn.Write(response); err != nil {
-		return nil, nil, err
-	}
-	clogger.Debugf("receiver handshake:\n%v", hexkey(response))
-	token, err = newSession(initNonce, recNonce, randomPrivKey, remoteRandomPubKey)
-	return token, remotePubKey, err
-}
-
-// authResp is called by peer if it accepted (but not
-// initiated) the connection from the remote. It is passed the initiator
-// handshake received and the session token belonging to the
-// remote initiator.
-//
-// The first return value is the authentication response (aka receiver
-// handshake) that is to be sent to the remote initiator.
-func authResp(auth, sessionToken []byte, prvKey *ecdsa.PrivateKey) (
-	authResp, respNonce, initNonce, remotePubKeyS []byte,
-	randomPrivKey *ecdsa.PrivateKey,
-	remoteRandomPubKey *ecdsa.PublicKey,
-	err error,
-) {
-	// they prove that msg is meant for me,
-	// I prove I possess private key if i can read it
-	msg, err := crypto.Decrypt(prvKey, auth)
-	if err != nil {
-		return
-	}
-
-	remotePubKeyS = msg[sigLen+shaLen : sigLen+shaLen+pubLen]
-	remotePubKey, _ := importPublicKey(remotePubKeyS)
-
-	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(prvKey).GenerateShared(ecies.ImportECDSAPublic(remotePubKey), sskLen, sskLen); err != nil {
-			return
-		}
-		// 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[authMsgLen-shaLen-1 : authMsgLen-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
-	var signedMsg = xor(sessionToken, initNonce)
-	var remoteRandomPubKeyS []byte
-	if remoteRandomPubKeyS, err = secp256k1.RecoverPubkey(signedMsg, msg[:sigLen]); err != nil {
-		return
-	}
-	// convert to ECDSA standard
-	if remoteRandomPubKey, err = importPublicKey(remoteRandomPubKeyS); err != nil {
-		return
-	}
-
-	// now we find ourselves a long task too, fill it random
-	var resp = make([]byte, authRespLen)
-	// generate shaLen long nonce
-	respNonce = resp[pubLen : pubLen+shaLen]
-	if _, err = rand.Read(respNonce); err != nil {
-		return
-	}
-	// generate random keypair for session
-	if randomPrivKey, err = crypto.GenerateKey(); err != nil {
-		return
-	}
-	// responder auth message
-	// E(remote-pubk, ecdhe-random-pubk || nonce || 0x0)
-	var randomPubKeyS []byte
-	if randomPubKeyS, err = exportPublicKey(&randomPrivKey.PublicKey); err != nil {
-		return
-	}
-	copy(resp[:pubLen], randomPubKeyS)
-	// nonce is already in the slice
-	resp[authRespLen-1] = tokenFlag
-
-	// encrypt using remote-pubk
-	// auth = eciesEncrypt(remote-pubk, msg)
-	// why not encrypt with ecdhe-random-remote
-	if authResp, err = crypto.Encrypt(remotePubKey, resp); err != nil {
-		return
-	}
-	return
-}
-
-// newSession is called after the handshake is completed. The
-// arguments are values negotiated in the handshake. The return value
-// is a new session Token to be remembered for the next time we
-// connect with this peer.
-func newSession(initNonce, respNonce []byte, privKey *ecdsa.PrivateKey, remoteRandomPubKey *ecdsa.PublicKey) ([]byte, error) {
-	// 3) Now we can trust ecdhe-random-pubk to derive new keys
-	//ecdhe-shared-secret = ecdh.agree(ecdhe-random, remote-ecdhe-random-pubk)
-	pubKey := ecies.ImportECDSAPublic(remoteRandomPubKey)
-	dhSharedSecret, err := ecies.ImportECDSA(privKey).GenerateShared(pubKey, sskLen, sskLen)
-	if err != nil {
-		return nil, err
-	}
-	sharedSecret := crypto.Sha3(dhSharedSecret, crypto.Sha3(respNonce, initNonce))
-	sessionToken := crypto.Sha3(sharedSecret)
-	return sessionToken, nil
-}
-
-// importPublicKey unmarshals 512 bit public keys.
-func importPublicKey(pubKey []byte) (pubKeyEC *ecdsa.PublicKey, err error) {
-	var pubKey65 []byte
-	switch len(pubKey) {
-	case 64:
-		// add 'uncompressed key' flag
-		pubKey65 = append([]byte{0x04}, pubKey...)
-	case 65:
-		pubKey65 = pubKey
-	default:
-		return nil, fmt.Errorf("invalid public key length %v (expect 64/65)", len(pubKey))
-	}
-	return crypto.ToECDSAPub(pubKey65), nil
-}
-
-func exportPublicKey(pubKeyEC *ecdsa.PublicKey) (pubKey []byte, err error) {
-	if pubKeyEC == nil {
-		return nil, fmt.Errorf("no ECDSA public key given")
-	}
-	return crypto.FromECDSAPub(pubKeyEC)[1:], nil
-}
-
-func xor(one, other []byte) (xor []byte) {
-	xor = make([]byte, len(one))
-	for i := 0; i < len(one); i++ {
-		xor[i] = one[i] ^ other[i]
-	}
-	return xor
-}