first stab at integrating crypto in our p2p
- abstract the entire handshake logic in cryptoId.Run() taking session-relevant parameters - changes in peer to accomodate how the encryption layer would be switched on - modify arguments of handshake components - fixed test getting the wrong pubkey but it till crashes on DH in newSession()
This commit is contained in:
zelig
Felix Lange
parent
1803c65e40
commit
e252c634cb
@ -4,6 +4,7 @@ import (
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"crypto/ecdsa"
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"crypto/rand"
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"fmt"
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"io"
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"github.com/ethereum/go-ethereum/crypto"
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"github.com/obscuren/ecies"
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@ -53,19 +54,35 @@ func newCryptoId(id ClientIdentity) (self *cryptoId, err error) {
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return
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}
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func (self *cryptoId) Run(remotePubKeyDER []byte) (rw *secretRW) {
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if self.initiator {
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auth, initNonce, randomPrvKey, randomPubKey, err := initiator.initAuth(remotePubKeyDER, sessionToken)
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respNonce, remoteRandomPubKey, _, _ := initiator.verifyAuthResp(response)
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} else {
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// we are listening connection. we are responders in the haandshake.
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// Extract info from the authentication. The initiator starts by sending us a handshake that we need to respond to.
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response, remoteRespNonce, remoteInitNonce, remoteRandomPrivKey, _ := responder.verifyAuth(auth, sessionToken, pubInit)
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func (self *cryptoId) Run(conn io.ReadWriter, remotePubKeyDER []byte, sessionToken []byte, initiator bool) (token []byte, rw *secretRW, err error) {
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var auth, initNonce, recNonce []byte
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var randomPrivKey *ecdsa.PrivateKey
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var remoteRandomPubKey *ecdsa.PublicKey
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if initiator {
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if auth, initNonce, randomPrivKey, _, err = self.startHandshake(remotePubKeyDER, sessionToken); err != nil {
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return
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}
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initSessionToken, initSecretRW, _ := initiator.newSession(initNonce, respNonce, auth, randomPrvKey, remoteRandomPubKey)
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respSessionToken, respSecretRW, _ := responder.newSession(remoteInitNonce, remoteRespNonce, auth, remoteRandomPrivKey, randomPubKey)
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conn.Write(auth)
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var response []byte
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conn.Read(response)
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// write out auth message
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// wait for response, then call complete
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if recNonce, remoteRandomPubKey, _, err = self.completeHandshake(response); err != nil {
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return
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}
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} else {
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conn.Read(auth)
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// we are listening connection. we are responders in the handshake.
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// Extract info from the authentication. The initiator starts by sending us a handshake that we need to respond to.
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// so we read auth message first, then respond
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var response []byte
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if response, recNonce, initNonce, randomPrivKey, err = self.respondToHandshake(auth, remotePubKeyDER, sessionToken); err != nil {
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return
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}
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remoteRandomPubKey = &randomPrivKey.PublicKey
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conn.Write(response)
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}
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return self.newSession(initNonce, recNonce, auth, randomPrivKey, remoteRandomPubKey)
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}
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/* startHandshake is called by peer if it initiated the connection.
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@ -83,9 +100,9 @@ The handshake is the process by which the peers establish their connection for a
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*/
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func (self *cryptoId) startHandshake(remotePubKeyDER, sessionToken []byte) (auth []byte, initNonce []byte, randomPrvKey *ecdsa.PrivateKey, randomPubKey *ecdsa.PublicKey, err error) {
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func (self *cryptoId) startHandshake(remotePubKeyDER, sessionToken []byte) (auth []byte, initNonce []byte, randomPrvKey *ecdsa.PrivateKey, remotePubKey *ecdsa.PublicKey, err error) {
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// session init, common to both parties
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remotePubKey := crypto.ToECDSAPub(remotePubKeyDER)
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remotePubKey = crypto.ToECDSAPub(remotePubKeyDER)
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if remotePubKey == nil {
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err = fmt.Errorf("invalid remote public key")
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return
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@ -160,8 +177,14 @@ func (self *cryptoId) startHandshake(remotePubKeyDER, sessionToken []byte) (auth
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}
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// verifyAuth is called by peer if it accepted (but not initiated) the connection
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func (self *cryptoId) respondToHandshake(auth, sessionToken []byte, remotePubKey *ecdsa.PublicKey) (authResp []byte, respNonce []byte, initNonce []byte, randomPrvKey *ecdsa.PrivateKey, err error) {
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func (self *cryptoId) respondToHandshake(auth, remotePubKeyDER, sessionToken []byte) (authResp []byte, respNonce []byte, initNonce []byte, randomPrivKey *ecdsa.PrivateKey, err error) {
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var msg []byte
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remotePubKey := crypto.ToECDSAPub(remotePubKeyDER)
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if remotePubKey == nil {
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err = fmt.Errorf("invalid public key")
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return
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}
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fmt.Printf("encrypted message received: %v %x\n used pubkey: %x\n", len(auth), auth, crypto.FromECDSAPub(self.pubKey))
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// they prove that msg is meant for me,
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// I prove I possess private key if i can read it
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@ -210,12 +233,12 @@ func (self *cryptoId) respondToHandshake(auth, sessionToken []byte, remotePubKey
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return
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}
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// generate random keypair for session
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if randomPrvKey, err = crypto.GenerateKey(); err != nil {
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if randomPrivKey, err = crypto.GenerateKey(); err != nil {
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return
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}
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// responder auth message
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// E(remote-pubk, ecdhe-random-pubk || nonce || 0x0)
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copy(resp[:keyLen], crypto.FromECDSAPub(&randomPrvKey.PublicKey))
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copy(resp[:keyLen], crypto.FromECDSAPub(&randomPrivKey.PublicKey))
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// nonce is already in the slice
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resp[resLen-1] = tokenFlag
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@ -11,44 +11,43 @@ import (
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func TestCryptoHandshake(t *testing.T) {
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var err error
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var sessionToken []byte
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prvInit, _ := crypto.GenerateKey()
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pubInit := &prvInit.PublicKey
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prvResp, _ := crypto.GenerateKey()
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pubResp := &prvResp.PublicKey
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prv0, _ := crypto.GenerateKey()
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pub0 := &prv0.PublicKey
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prv1, _ := crypto.GenerateKey()
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pub1 := &prv1.PublicKey
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var initiator, responder *cryptoId
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if initiator, err = newCryptoId(&peerId{crypto.FromECDSA(prvInit), crypto.FromECDSAPub(pubInit)}); err != nil {
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var initiator, receiver *cryptoId
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if initiator, err = newCryptoId(&peerId{crypto.FromECDSA(prv0), crypto.FromECDSAPub(pub0)}); err != nil {
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return
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}
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if responder, err = newCryptoId(&peerId{crypto.FromECDSA(prvResp), crypto.FromECDSAPub(pubResp)}); err != nil {
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if receiver, err = newCryptoId(&peerId{crypto.FromECDSA(prv1), crypto.FromECDSAPub(pub1)}); err != nil {
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return
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}
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auth, initNonce, randomPrvKey, randomPubKey, _ := initiator.initAuth(responder.pubKeyDER, sessionToken)
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// simulate handshake by feeding output to input
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auth, initNonce, randomPrivKey, _, _ := initiator.startHandshake(receiver.pubKeyDER, sessionToken)
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response, remoteRecNonce, remoteInitNonce, remoteRandomPrivKey, _ := receiver.respondToHandshake(auth, crypto.FromECDSAPub(pub0), sessionToken)
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recNonce, remoteRandomPubKey, _, _ := initiator.completeHandshake(response)
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response, remoteRespNonce, remoteInitNonce, remoteRandomPrivKey, _ := responder.verifyAuth(auth, sessionToken, pubInit)
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initSessionToken, initSecretRW, _ := initiator.newSession(initNonce, recNonce, auth, randomPrivKey, remoteRandomPubKey)
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recSessionToken, recSecretRW, _ := receiver.newSession(remoteInitNonce, remoteRecNonce, auth, remoteRandomPrivKey, &randomPrivKey.PublicKey)
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respNonce, remoteRandomPubKey, _, _ := initiator.verifyAuthResp(response)
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fmt.Printf("%x\n%x\n%x\n%x\n%x\n%x\n%x\n%x\n%x\n%x\n", auth, initNonce, response, remoteRecNonce, remoteInitNonce, remoteRandomPubKey, recNonce, &randomPrivKey.PublicKey, initSessionToken, initSecretRW)
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initSessionToken, initSecretRW, _ := initiator.newSession(initNonce, respNonce, auth, randomPrvKey, remoteRandomPubKey)
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respSessionToken, respSecretRW, _ := responder.newSession(remoteInitNonce, remoteRespNonce, auth, remoteRandomPrivKey, randomPubKey)
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fmt.Printf("%x\n%x\n%x\n%x\n%x\n%x\n%x\n%x\n%x\n%x\n", auth, initNonce, response, remoteRespNonce, remoteInitNonce, remoteRandomPubKey, respNonce, randomPubKey, initSessionToken, initSecretRW)
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if !bytes.Equal(initSessionToken, respSessionToken) {
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if !bytes.Equal(initSessionToken, recSessionToken) {
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t.Errorf("session tokens do not match")
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}
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// aesSecret, macSecret, egressMac, ingressMac
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if !bytes.Equal(initSecretRW.aesSecret, respSecretRW.aesSecret) {
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if !bytes.Equal(initSecretRW.aesSecret, recSecretRW.aesSecret) {
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t.Errorf("AES secrets do not match")
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}
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if !bytes.Equal(initSecretRW.macSecret, respSecretRW.macSecret) {
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if !bytes.Equal(initSecretRW.macSecret, recSecretRW.macSecret) {
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t.Errorf("macSecrets do not match")
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}
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if !bytes.Equal(initSecretRW.egressMac, respSecretRW.egressMac) {
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if !bytes.Equal(initSecretRW.egressMac, recSecretRW.egressMac) {
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t.Errorf("egressMacs do not match")
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}
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if !bytes.Equal(initSecretRW.ingressMac, respSecretRW.ingressMac) {
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if !bytes.Equal(initSecretRW.ingressMac, recSecretRW.ingressMac) {
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t.Errorf("ingressMacs do not match")
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}
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33
p2p/peer.go
33
p2p/peer.go
@ -222,9 +222,9 @@ func (p *Peer) loop() (reason DiscReason, err error) {
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defer close(p.closed)
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defer p.conn.Close()
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var readLoop func(chan Msg, chan error, chan bool)
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var readLoop func(chan<- Msg, chan<- error, <-chan bool)
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if p.cryptoHandshake {
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if readLoop, err := p.handleCryptoHandshake(); err != nil {
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if readLoop, err = p.handleCryptoHandshake(); err != nil {
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// from here on everything can be encrypted, authenticated
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return DiscProtocolError, err // no graceful disconnect
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}
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@ -332,20 +332,33 @@ func (p *Peer) dispatch(msg Msg, protoDone chan struct{}) (wait bool, err error)
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return wait, nil
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}
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func (p *Peer) handleCryptoHandshake() (err error) {
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type readLoop func(chan<- Msg, chan<- error, <-chan bool)
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func (p *Peer) handleCryptoHandshake() (loop readLoop, err error) {
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// cryptoId is just created for the lifecycle of the handshake
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// it is survived by an encrypted readwriter
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if p.dialAddr != 0 { // this should have its own method Outgoing() bool
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var initiator bool
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var sessionToken []byte
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if p.dialAddr != nil { // this should have its own method Outgoing() bool
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initiator = true
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}
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// create crypto layer
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cryptoId := newCryptoId(p.identity, initiator, sessionToken)
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// run on peer
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if rw, err := cryptoId.Run(p.Pubkey()); err != nil {
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return err
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// this could in principle run only once but maybe we want to allow
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// identity switching
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var crypto *cryptoId
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if crypto, err = newCryptoId(p.ourID); err != nil {
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return
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}
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p.conn = rw.Run(p.conn)
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// run on peer
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// this bit handles the handshake and creates a secure communications channel with
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// var rw *secretRW
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if sessionToken, _, err = crypto.Run(p.conn, p.Pubkey(), sessionToken, initiator); err != nil {
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return
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}
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loop = func(msg chan<- Msg, err chan<- error, next <-chan bool) {
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// this is the readloop :)
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}
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return
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}
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func (p *Peer) startBaseProtocol() {
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