diff --git a/p2p/crypto.go b/p2p/crypto.go
index b6d600826f7106d856752300a5be9aee25997baa..dbef022ccde41801681dc51db6073797138e080f 100644
--- a/p2p/crypto.go
+++ b/p2p/crypto.go
@@ -12,11 +12,12 @@ import (
)
var (
- sskLen int = 16 // ecies.MaxSharedKeyLength(pubKey) / 2
- sigLen int = 65 // elliptic S256
- keyLen int = 32 // ECDSA
- msgLen int = sigLen + 3*keyLen + 1 // 162
- resLen int = 65 //
+ 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
)
// aesSecret, macSecret, egressMac, ingress
@@ -25,20 +26,21 @@ type secretRW struct {
}
type cryptoId struct {
- prvKey *ecdsa.PrivateKey
- pubKey *ecdsa.PublicKey
- pubKeyDER []byte
+ prvKey *ecdsa.PrivateKey
+ pubKey *ecdsa.PublicKey
+ pubKeyS []byte
}
func newCryptoId(id ClientIdentity) (self *cryptoId, err error) {
// will be at server init
- var prvKeyDER []byte = id.PrivKey()
- if prvKeyDER == nil {
+ var prvKeyS []byte = id.PrivKey()
+ if prvKeyS == nil {
err = fmt.Errorf("no private key for client")
return
}
- // initialise ecies private key via importing DER encoded keys (known via our own clientIdentity)
- var prvKey = crypto.ToECDSA(prvKeyDER)
+ // initialise ecies private key via importing keys (known via our own clientIdentity)
+ // the key format is what elliptic package is using: elliptic.Marshal(Curve, X, Y)
+ var prvKey = crypto.ToECDSA(prvKeyS)
if prvKey == nil {
err = fmt.Errorf("invalid private key for client")
return
@@ -50,16 +52,16 @@ func newCryptoId(id ClientIdentity) (self *cryptoId, err error) {
// to be created at server init shared between peers and sessions
// for reuse, call wth ReadAt, no reset seek needed
}
- self.pubKeyDER = id.Pubkey()
+ self.pubKeyS = id.Pubkey()
return
}
-func (self *cryptoId) Run(conn io.ReadWriter, remotePubKeyDER []byte, sessionToken []byte, initiator bool) (token []byte, rw *secretRW, err error) {
+func (self *cryptoId) Run(conn io.ReadWriter, remotePubKeyS []byte, sessionToken []byte, initiator bool) (token []byte, rw *secretRW, err error) {
var auth, initNonce, recNonce []byte
var randomPrivKey *ecdsa.PrivateKey
var remoteRandomPubKey *ecdsa.PublicKey
if initiator {
- if auth, initNonce, randomPrivKey, _, err = self.startHandshake(remotePubKeyDER, sessionToken); err != nil {
+ if auth, initNonce, randomPrivKey, _, err = self.startHandshake(remotePubKeyS, sessionToken); err != nil {
return
}
conn.Write(auth)
@@ -76,10 +78,9 @@ func (self *cryptoId) Run(conn io.ReadWriter, remotePubKeyDER []byte, sessionTok
// 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
var response []byte
- if response, recNonce, initNonce, randomPrivKey, err = self.respondToHandshake(auth, remotePubKeyDER, sessionToken); err != nil {
+ if response, recNonce, initNonce, randomPrivKey, remoteRandomPubKey, err = self.respondToHandshake(auth, remotePubKeyS, sessionToken); err != nil {
return
}
- remoteRandomPubKey = &randomPrivKey.PublicKey
conn.Write(response)
}
return self.newSession(initNonce, recNonce, auth, randomPrivKey, remoteRandomPubKey)
@@ -100,11 +101,29 @@ The handshake is the process by which the peers establish their connection for a
*/
-func (self *cryptoId) startHandshake(remotePubKeyDER, sessionToken []byte) (auth []byte, initNonce []byte, randomPrvKey *ecdsa.PrivateKey, remotePubKey *ecdsa.PublicKey, err error) {
+func ImportPublicKey(pubKey []byte) (pubKeyEC *ecdsa.PublicKey, err error) {
+ var pubKey65 []byte
+ switch len(pubKey) {
+ case 64:
+ 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 (self *cryptoId) startHandshake(remotePubKeyS, sessionToken []byte) (auth []byte, initNonce []byte, randomPrvKey *ecdsa.PrivateKey, remotePubKey *ecdsa.PublicKey, err error) {
// session init, common to both parties
- remotePubKey = crypto.ToECDSAPub(remotePubKeyDER)
- if remotePubKey == nil {
- err = fmt.Errorf("invalid remote public key")
+ if remotePubKey, err = ImportPublicKey(remotePubKeyS); err != nil {
return
}
@@ -116,8 +135,6 @@ func (self *cryptoId) startHandshake(remotePubKeyDER, sessionToken []byte) (auth
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 {
// for known peers, we use stored token from the previous session
@@ -128,9 +145,7 @@ func (self *cryptoId) startHandshake(remotePubKeyDER, 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)
- // generate sskLen long nonce
initNonce = msg[msgLen-keyLen-1 : msgLen-1]
- // nonce = msg[msgLen-sskLen-1 : msgLen-1]
if _, err = rand.Read(initNonce); err != nil {
return
}
@@ -150,48 +165,45 @@ func (self *cryptoId) startHandshake(remotePubKeyDER, sessionToken []byte) (auth
if signature, err = crypto.Sign(sharedSecret, randomPrvKey); err != nil {
return
}
- fmt.Printf("signature generated: %v %x", len(signature), signature)
// message
// 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(&randomPrvKey.PublicKey)))
+ var randomPubKey64 []byte
+ if randomPubKey64, err = ExportPublicKey(&randomPrvKey.PublicKey); err != nil {
+ return
+ }
+ copy(msg[sigLen:sigLen+keyLen], crypto.Sha3(randomPubKey64))
// pubkey copied to the correct segment.
- copy(msg[sigLen+keyLen:sigLen+2*keyLen], self.pubKeyDER)
+ copy(msg[sigLen+keyLen:sigLen+keyLen+pubLen], self.pubKeyS)
// nonce is already in the slice
// stick tokenFlag byte to the end
msg[msgLen-1] = tokenFlag
- fmt.Printf("plaintext message generated: %v %x", len(msg), msg)
-
// encrypt using remote-pubk
// auth = eciesEncrypt(remote-pubk, msg)
if auth, err = crypto.Encrypt(remotePubKey, msg); err != nil {
return
}
- fmt.Printf("encrypted message generated: %v %x\n used pubkey: %x\n", len(auth), auth, crypto.FromECDSAPub(remotePubKey))
return
}
// verifyAuth is called by peer if it accepted (but not initiated) the connection
-func (self *cryptoId) respondToHandshake(auth, remotePubKeyDER, sessionToken []byte) (authResp []byte, respNonce []byte, initNonce []byte, randomPrivKey *ecdsa.PrivateKey, err error) {
+func (self *cryptoId) respondToHandshake(auth, remotePubKeyS, sessionToken []byte) (authResp []byte, respNonce []byte, initNonce []byte, randomPrivKey *ecdsa.PrivateKey, remoteRandomPubKey *ecdsa.PublicKey, err error) {
var msg []byte
- remotePubKey := crypto.ToECDSAPub(remotePubKeyDER)
- if remotePubKey == nil {
- err = fmt.Errorf("invalid public key")
+ var remotePubKey *ecdsa.PublicKey
+ if remotePubKey, err = ImportPublicKey(remotePubKeyS); err != nil {
return
}
- 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,
// I prove I possess private key if i can read it
if msg, err = crypto.Decrypt(self.prvKey, auth); err != nil {
return
}
- fmt.Printf("\nplaintext message retrieved: %v %x\n", len(msg), msg)
var tokenFlag byte
if sessionToken == nil {
@@ -201,7 +213,6 @@ func (self *cryptoId) respondToHandshake(auth, remotePubKeyDER, sessionToken []b
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
@@ -214,21 +225,19 @@ func (self *cryptoId) respondToHandshake(auth, remotePubKeyDER, sessionToken []b
// 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 remoteRandomPubKeyDER []byte
- if remoteRandomPubKeyDER, err = secp256k1.RecoverPubkey(signedMsg, msg[:sigLen]); err != nil {
+ var remoteRandomPubKeyS []byte
+ if remoteRandomPubKeyS, 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")
+ if remoteRandomPubKey, err = ImportPublicKey(remoteRandomPubKeyS); err != nil {
return
}
// 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]
+ respNonce = resp[pubLen : pubLen+keyLen]
if _, err = rand.Read(respNonce); err != nil {
return
}
@@ -238,7 +247,11 @@ func (self *cryptoId) respondToHandshake(auth, remotePubKeyDER, sessionToken []b
}
// responder auth message
// E(remote-pubk, ecdhe-random-pubk || nonce || 0x0)
- copy(resp[:keyLen], crypto.FromECDSAPub(&randomPrivKey.PublicKey))
+ var randomPubKeyS []byte
+ if randomPubKeyS, err = ExportPublicKey(&randomPrivKey.PublicKey); err != nil {
+ return
+ }
+ copy(resp[:pubLen], randomPubKeyS)
// nonce is already in the slice
resp[resLen-1] = tokenFlag
@@ -259,11 +272,9 @@ func (self *cryptoId) completeHandshake(auth []byte) (respNonce []byte, remoteRa
return
}
- respNonce = msg[resLen-keyLen-1 : resLen-1]
- var remoteRandomPubKeyDER = msg[:keyLen]
- remoteRandomPubKey = crypto.ToECDSAPub(remoteRandomPubKeyDER)
- if remoteRandomPubKey == nil {
- err = fmt.Errorf("invalid ecdh random remote public key")
+ respNonce = msg[pubLen : pubLen+keyLen]
+ var remoteRandomPubKeyS = msg[:pubLen]
+ if remoteRandomPubKey, err = ImportPublicKey(remoteRandomPubKeyS); err != nil {
return
}
if msg[resLen-1] == 0x01 {
diff --git a/p2p/crypto_test.go b/p2p/crypto_test.go
index 89baca084445c0b86103248014dea8c00aa1a72c..8000efaf199bdc5845fc1b34f9d1612bdad6d1c9 100644
--- a/p2p/crypto_test.go
+++ b/p2p/crypto_test.go
@@ -2,16 +2,76 @@ package p2p
import (
"bytes"
+ // "crypto/ecdsa"
+ // "crypto/elliptic"
+ // "crypto/rand"
"fmt"
"testing"
"github.com/ethereum/go-ethereum/crypto"
+ "github.com/obscuren/ecies"
)
+func TestPublicKeyEncoding(t *testing.T) {
+ prv0, _ := crypto.GenerateKey() // = ecdsa.GenerateKey(crypto.S256(), rand.Reader)
+ pub0 := &prv0.PublicKey
+ pub0s := crypto.FromECDSAPub(pub0)
+ pub1, err := ImportPublicKey(pub0s)
+ if err != nil {
+ t.Errorf("%v", err)
+ }
+ eciesPub1 := ecies.ImportECDSAPublic(pub1)
+ if eciesPub1 == nil {
+ t.Errorf("invalid ecdsa public key")
+ }
+ pub1s, err := ExportPublicKey(pub1)
+ if err != nil {
+ t.Errorf("%v", err)
+ }
+ if len(pub1s) != 64 {
+ t.Errorf("wrong length expect 64, got", len(pub1s))
+ }
+ pub2, err := ImportPublicKey(pub1s)
+ if err != nil {
+ t.Errorf("%v", err)
+ }
+ pub2s, err := ExportPublicKey(pub2)
+ if err != nil {
+ t.Errorf("%v", err)
+ }
+ if !bytes.Equal(pub1s, pub2s) {
+ t.Errorf("exports dont match")
+ }
+ pub2sEC := crypto.FromECDSAPub(pub2)
+ if !bytes.Equal(pub0s, pub2sEC) {
+ t.Errorf("exports dont match")
+ }
+}
+
+func TestSharedSecret(t *testing.T) {
+ prv0, _ := crypto.GenerateKey() // = ecdsa.GenerateKey(crypto.S256(), rand.Reader)
+ pub0 := &prv0.PublicKey
+ prv1, _ := crypto.GenerateKey()
+ pub1 := &prv1.PublicKey
+
+ ss0, err := ecies.ImportECDSA(prv0).GenerateShared(ecies.ImportECDSAPublic(pub1), sskLen, sskLen)
+ if err != nil {
+ return
+ }
+ ss1, err := ecies.ImportECDSA(prv1).GenerateShared(ecies.ImportECDSAPublic(pub0), sskLen, sskLen)
+ if err != nil {
+ return
+ }
+ t.Logf("Secret:\n%v %x\n%v %x", len(ss0), ss0, len(ss0), ss1)
+ if !bytes.Equal(ss0, ss1) {
+ t.Errorf("dont match :(")
+ }
+}
+
func TestCryptoHandshake(t *testing.T) {
var err error
var sessionToken []byte
- prv0, _ := crypto.GenerateKey()
+ prv0, _ := crypto.GenerateKey() // = ecdsa.GenerateKey(crypto.S256(), rand.Reader)
pub0 := &prv0.PublicKey
prv1, _ := crypto.GenerateKey()
pub1 := &prv1.PublicKey
@@ -26,17 +86,35 @@ func TestCryptoHandshake(t *testing.T) {
// simulate handshake by feeding output to input
// initiator sends handshake 'auth'
- auth, initNonce, randomPrivKey, _, _ := initiator.startHandshake(receiver.pubKeyDER, sessionToken)
+ auth, initNonce, randomPrivKey, _, err := initiator.startHandshake(receiver.pubKeyS, sessionToken)
+ if err != nil {
+ t.Errorf("%v", err)
+ }
+
// receiver reads auth and responds with response
- response, remoteRecNonce, remoteInitNonce, remoteRandomPrivKey, _ := receiver.respondToHandshake(auth, crypto.FromECDSAPub(pub0), sessionToken)
+ response, remoteRecNonce, remoteInitNonce, remoteRandomPrivKey, remoteInitRandomPubKey, err := receiver.respondToHandshake(auth, crypto.FromECDSAPub(pub0), sessionToken)
+ if err != nil {
+ t.Errorf("%v", err)
+ }
+
// initiator reads receiver's response and the key exchange completes
- recNonce, remoteRandomPubKey, _, _ := initiator.completeHandshake(response)
+ recNonce, remoteRandomPubKey, _, err := initiator.completeHandshake(response)
+ if err != nil {
+ t.Errorf("%v", err)
+ }
// now both parties should have the same session parameters
- initSessionToken, initSecretRW, _ := initiator.newSession(initNonce, recNonce, auth, randomPrivKey, remoteRandomPubKey)
- recSessionToken, recSecretRW, _ := receiver.newSession(remoteInitNonce, remoteRecNonce, auth, remoteRandomPrivKey, &randomPrivKey.PublicKey)
+ initSessionToken, initSecretRW, err := initiator.newSession(initNonce, recNonce, auth, randomPrivKey, remoteRandomPubKey)
+ if err != nil {
+ t.Errorf("%v", err)
+ }
+
+ recSessionToken, recSecretRW, err := receiver.newSession(remoteInitNonce, remoteRecNonce, auth, remoteRandomPrivKey, remoteInitRandomPubKey)
+ if err != nil {
+ t.Errorf("%v", err)
+ }
- 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)
+ fmt.Printf("\nauth %x\ninitNonce %x\nresponse%x\nremoteRecNonce %x\nremoteInitNonce %x\nremoteRandomPubKey %x\nrecNonce %x\nremoteInitRandomPubKey %x\ninitSessionToken %x\n\n", auth, initNonce, response, remoteRecNonce, remoteInitNonce, remoteRandomPubKey, recNonce, remoteInitRandomPubKey, initSessionToken)
if !bytes.Equal(initNonce, remoteInitNonce) {
t.Errorf("nonces do not match")