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-rw-r--r--src/device.go18
-rw-r--r--src/kdf_test.go76
-rw-r--r--src/noise_helpers.go86
-rw-r--r--src/noise_protocol.go179
-rw-r--r--src/noise_test.go38
-rw-r--r--src/noise_types.go (renamed from src/noise.go)6
-rw-r--r--src/tai64.go23
7 files changed, 422 insertions, 4 deletions
diff --git a/src/device.go b/src/device.go
index d03057d..9f1daa6 100644
--- a/src/device.go
+++ b/src/device.go
@@ -1,12 +1,17 @@
package main
import (
+ "math/rand"
"sync"
)
+/* TODO: Locking may be a little broad here
+ */
+
type Device struct {
mutex sync.RWMutex
peers map[NoisePublicKey]*Peer
+ sessions map[uint32]*Handshake
privateKey NoisePrivateKey
publicKey NoisePublicKey
fwMark uint32
@@ -14,6 +19,19 @@ type Device struct {
routingTable RoutingTable
}
+func (dev *Device) NewID(h *Handshake) uint32 {
+ dev.mutex.Lock()
+ defer dev.mutex.Unlock()
+ for {
+ id := rand.Uint32()
+ _, ok := dev.sessions[id]
+ if !ok {
+ dev.sessions[id] = h
+ return id
+ }
+ }
+}
+
func (dev *Device) RemovePeer(key NoisePublicKey) {
dev.mutex.Lock()
defer dev.mutex.Unlock()
diff --git a/src/kdf_test.go b/src/kdf_test.go
new file mode 100644
index 0000000..0cce81d
--- /dev/null
+++ b/src/kdf_test.go
@@ -0,0 +1,76 @@
+package main
+
+import (
+ "encoding/hex"
+ "testing"
+)
+
+type KDFTest struct {
+ key string
+ input string
+ t0 string
+ t1 string
+ t2 string
+}
+
+func assertEquals(t *testing.T, a string, b string) {
+ if a != b {
+ t.Fatal("expected", a, "=", b)
+ }
+}
+
+func TestKDF(t *testing.T) {
+ tests := []KDFTest{
+ {
+ key: "746573742d6b6579",
+ input: "746573742d696e707574",
+ t0: "6f0e5ad38daba1bea8a0d213688736f19763239305e0f58aba697f9ffc41c633",
+ t1: "df1194df20802a4fe594cde27e92991c8cae66c366e8106aaa937a55fa371e8a",
+ t2: "fac6e2745a325f5dc5d11a5b165aad08b0ada28e7b4e666b7c077934a4d76c24",
+ },
+ {
+ key: "776972656775617264",
+ input: "776972656775617264",
+ t0: "491d43bbfdaa8750aaf535e334ecbfe5129967cd64635101c566d4caefda96e8",
+ t1: "1e71a379baefd8a79aa4662212fcafe19a23e2b609a3db7d6bcba8f560e3d25f",
+ t2: "31e1ae48bddfbe5de38f295e5452b1909a1b4e38e183926af3780b0c1e1f0160",
+ },
+ {
+ key: "",
+ input: "",
+ t0: "8387b46bf43eccfcf349552a095d8315c4055beb90208fb1be23b894bc2ed5d0",
+ t1: "58a0e5f6faefccf4807bff1f05fa8a9217945762040bcec2f4b4a62bdfe0e86e",
+ t2: "0ce6ea98ec548f8e281e93e32db65621c45eb18dc6f0a7ad94178610a2f7338e",
+ },
+ }
+
+ for _, test := range tests {
+ key, _ := hex.DecodeString(test.key)
+ input, _ := hex.DecodeString(test.input)
+ t0, t1, t2 := KDF3(key, input)
+ t0s := hex.EncodeToString(t0[:])
+ t1s := hex.EncodeToString(t1[:])
+ t2s := hex.EncodeToString(t2[:])
+ assertEquals(t, t0s, test.t0)
+ assertEquals(t, t1s, test.t1)
+ assertEquals(t, t2s, test.t2)
+ }
+
+ for _, test := range tests {
+ key, _ := hex.DecodeString(test.key)
+ input, _ := hex.DecodeString(test.input)
+ t0, t1 := KDF2(key, input)
+ t0s := hex.EncodeToString(t0[:])
+ t1s := hex.EncodeToString(t1[:])
+ assertEquals(t, t0s, test.t0)
+ assertEquals(t, t1s, test.t1)
+ }
+
+ for _, test := range tests {
+ key, _ := hex.DecodeString(test.key)
+ input, _ := hex.DecodeString(test.input)
+ t0 := KDF1(key, input)
+ t0s := hex.EncodeToString(t0[:])
+ assertEquals(t, t0s, test.t0)
+ }
+}
diff --git a/src/noise_helpers.go b/src/noise_helpers.go
new file mode 100644
index 0000000..df25011
--- /dev/null
+++ b/src/noise_helpers.go
@@ -0,0 +1,86 @@
+package main
+
+import (
+ "crypto/hmac"
+ "crypto/rand"
+ "golang.org/x/crypto/blake2s"
+ "golang.org/x/crypto/curve25519"
+ "hash"
+)
+
+/* KDF related functions.
+ * HMAC-based Key Derivation Function (HKDF)
+ * https://tools.ietf.org/html/rfc5869
+ */
+
+func HMAC(sum *[blake2s.Size]byte, key []byte, input []byte) {
+ mac := hmac.New(func() hash.Hash {
+ h, _ := blake2s.New256(nil)
+ return h
+ }, key)
+ mac.Write(input)
+ mac.Sum(sum[:0])
+}
+
+func KDF1(key []byte, input []byte) (t0 [blake2s.Size]byte) {
+ HMAC(&t0, key, input)
+ HMAC(&t0, t0[:], []byte{0x1})
+ return
+}
+
+func KDF2(key []byte, input []byte) (t0 [blake2s.Size]byte, t1 [blake2s.Size]byte) {
+ var prk [blake2s.Size]byte
+ HMAC(&prk, key, input)
+ HMAC(&t0, prk[:], []byte{0x1})
+ HMAC(&t1, prk[:], append(t0[:], 0x2))
+ return
+}
+
+func KDF3(key []byte, input []byte) (t0 [blake2s.Size]byte, t1 [blake2s.Size]byte, t2 [blake2s.Size]byte) {
+ var prk [blake2s.Size]byte
+ HMAC(&prk, key, input)
+ HMAC(&t0, prk[:], []byte{0x1})
+ HMAC(&t1, prk[:], append(t0[:], 0x2))
+ HMAC(&t2, prk[:], append(t1[:], 0x3))
+ return
+}
+
+/*
+ *
+ */
+
+func addToChainKey(c [blake2s.Size]byte, data []byte) [blake2s.Size]byte {
+ return KDF1(c[:], data)
+}
+
+func addToHash(h [blake2s.Size]byte, data []byte) [blake2s.Size]byte {
+ return blake2s.Sum256(append(h[:], data...))
+}
+
+/* Curve25519 wrappers
+ *
+ * TODO: Rethink this
+ */
+
+func newPrivateKey() (sk NoisePrivateKey, err error) {
+ // clamping: https://cr.yp.to/ecdh.html
+ _, err = rand.Read(sk[:])
+ sk[0] &= 248
+ sk[31] &= 127
+ sk[31] |= 64
+ return
+}
+
+func (sk *NoisePrivateKey) publicKey() (pk NoisePublicKey) {
+ apk := (*[NoisePublicKeySize]byte)(&pk)
+ ask := (*[NoisePrivateKeySize]byte)(sk)
+ curve25519.ScalarBaseMult(apk, ask)
+ return
+}
+
+func (sk *NoisePrivateKey) sharedSecret(pk NoisePublicKey) (ss [NoisePublicKeySize]byte) {
+ apk := (*[NoisePublicKeySize]byte)(&pk)
+ ask := (*[NoisePrivateKeySize]byte)(sk)
+ curve25519.ScalarMult(&ss, apk, ask)
+ return ss
+}
diff --git a/src/noise_protocol.go b/src/noise_protocol.go
new file mode 100644
index 0000000..e7c8774
--- /dev/null
+++ b/src/noise_protocol.go
@@ -0,0 +1,179 @@
+package main
+
+import (
+ "errors"
+ "golang.org/x/crypto/blake2s"
+ "golang.org/x/crypto/chacha20poly1305"
+ "golang.org/x/crypto/poly1305"
+ "sync"
+)
+
+const (
+ HandshakeInitialCreated = iota
+ HandshakeInitialConsumed
+ HandshakeResponseCreated
+)
+
+const (
+ NoiseConstruction = "Noise_IKpsk2_25519_ChaChaPoly_BLAKE2s"
+ WGIdentifier = "WireGuard v1 zx2c4 Jason@zx2c4.com"
+ WGLabelMAC1 = "mac1----"
+ WGLabelCookie = "cookie--"
+)
+
+const (
+ MessageInitalType = 1
+ MessageResponseType = 2
+ MessageCookieResponseType = 3
+ MessageTransportType = 4
+)
+
+type MessageInital struct {
+ Type uint32
+ Sender uint32
+ Ephemeral NoisePublicKey
+ Static [NoisePublicKeySize + poly1305.TagSize]byte
+ Timestamp [TAI64NSize + poly1305.TagSize]byte
+ Mac1 [blake2s.Size128]byte
+ Mac2 [blake2s.Size128]byte
+}
+
+type MessageResponse struct {
+ Type uint32
+ Sender uint32
+ Reciever uint32
+ Ephemeral NoisePublicKey
+ Empty [poly1305.TagSize]byte
+ Mac1 [blake2s.Size128]byte
+ Mac2 [blake2s.Size128]byte
+}
+
+type MessageTransport struct {
+ Type uint32
+ Reciever uint32
+ Counter uint64
+ Content []byte
+}
+
+type Handshake struct {
+ lock sync.Mutex
+ state int
+ chainKey [blake2s.Size]byte // chain key
+ hash [blake2s.Size]byte // hash value
+ staticStatic NoisePublicKey // precomputed DH(S_i, S_r)
+ ephemeral NoisePrivateKey // ephemeral secret key
+ remoteIndex uint32 // index for sending
+ device *Device
+ peer *Peer
+}
+
+var (
+ ZeroNonce [chacha20poly1305.NonceSize]byte
+ InitalChainKey [blake2s.Size]byte
+ InitalHash [blake2s.Size]byte
+)
+
+func init() {
+ InitalChainKey = blake2s.Sum256([]byte(NoiseConstruction))
+ InitalHash = blake2s.Sum256(append(InitalChainKey[:], []byte(WGIdentifier)...))
+}
+
+func (h *Handshake) Precompute() {
+ h.staticStatic = h.device.privateKey.sharedSecret(h.peer.publicKey)
+}
+
+func (h *Handshake) ConsumeMessageResponse(msg *MessageResponse) {
+
+}
+
+func (h *Handshake) addHash(data []byte) {
+ h.hash = addToHash(h.hash, data)
+}
+
+func (h *Handshake) addChain(data []byte) {
+ h.chainKey = addToChainKey(h.chainKey, data)
+}
+
+func (h *Handshake) CreateMessageInital() (*MessageInital, error) {
+ h.lock.Lock()
+ defer h.lock.Unlock()
+
+ // reset handshake
+
+ var err error
+ h.ephemeral, err = newPrivateKey()
+ if err != nil {
+ return nil, err
+ }
+ h.chainKey = InitalChainKey
+ h.hash = addToHash(InitalHash, h.device.publicKey[:])
+
+ // create ephemeral key
+
+ var msg MessageInital
+ msg.Type = MessageInitalType
+ msg.Sender = h.device.NewID(h)
+ msg.Ephemeral = h.ephemeral.publicKey()
+ h.chainKey = addToChainKey(h.chainKey, msg.Ephemeral[:])
+ h.hash = addToHash(h.hash, msg.Ephemeral[:])
+
+ // encrypt long-term "identity key"
+
+ func() {
+ var key [chacha20poly1305.KeySize]byte
+ ss := h.ephemeral.sharedSecret(h.peer.publicKey)
+ h.chainKey, key = KDF2(h.chainKey[:], ss[:])
+ aead, _ := chacha20poly1305.New(key[:])
+ aead.Seal(msg.Static[:0], ZeroNonce[:], h.device.publicKey[:], nil)
+ }()
+ h.addHash(msg.Static[:])
+
+ // encrypt timestamp
+
+ timestamp := Timestamp()
+ func() {
+ var key [chacha20poly1305.KeySize]byte
+ h.chainKey, key = KDF2(h.chainKey[:], h.staticStatic[:])
+ aead, _ := chacha20poly1305.New(key[:])
+ aead.Seal(msg.Timestamp[:0], ZeroNonce[:], timestamp[:], nil)
+ }()
+ h.addHash(msg.Timestamp[:])
+ h.state = HandshakeInitialCreated
+ return &msg, nil
+}
+
+func (h *Handshake) ConsumeMessageInitial(msg *MessageInital) error {
+ if msg.Type != MessageInitalType {
+ panic(errors.New("bug: invalid inital message type"))
+ }
+
+ hash := addToHash(InitalHash, h.device.publicKey[:])
+ chainKey := addToChainKey(InitalChainKey, msg.Ephemeral[:])
+ hash = addToHash(hash, msg.Ephemeral[:])
+
+ //
+
+ ephemeral, err := newPrivateKey()
+ if err != nil {
+ return err
+ }
+
+ // update handshake state
+
+ h.lock.Lock()
+ defer h.lock.Unlock()
+
+ h.hash = hash
+ h.chainKey = chainKey
+ h.remoteIndex = msg.Sender
+ h.ephemeral = ephemeral
+ h.state = HandshakeInitialConsumed
+
+ return nil
+
+}
+
+func (h *Handshake) CreateMessageResponse() []byte {
+
+ return nil
+}
diff --git a/src/noise_test.go b/src/noise_test.go
new file mode 100644
index 0000000..b3ea54f
--- /dev/null
+++ b/src/noise_test.go
@@ -0,0 +1,38 @@
+package main
+
+import (
+ "testing"
+)
+
+func TestHandshake(t *testing.T) {
+ var dev1 Device
+ var dev2 Device
+
+ var err error
+
+ dev1.privateKey, err = newPrivateKey()
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ dev2.privateKey, err = newPrivateKey()
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ var peer1 Peer
+ var peer2 Peer
+
+ peer1.publicKey = dev1.privateKey.publicKey()
+ peer2.publicKey = dev2.privateKey.publicKey()
+
+ var handshake1 Handshake
+ var handshake2 Handshake
+
+ handshake1.device = &dev1
+ handshake2.device = &dev2
+
+ handshake1.peer = &peer2
+ handshake2.peer = &peer1
+
+}
diff --git a/src/noise.go b/src/noise_types.go
index 5508f9a..6dae6b2 100644
--- a/src/noise.go
+++ b/src/noise_types.go
@@ -12,10 +12,8 @@ const (
)
type (
- NoisePublicKey [NoisePublicKeySize]byte
- NoisePrivateKey [NoisePrivateKeySize]byte
- NoiseSymmetricKey [NoiseSymmetricKeySize]byte
- NoiseNonce uint64 // padded to 12-bytes
+ NoisePublicKey [NoisePublicKeySize]byte
+ NoisePrivateKey [NoisePrivateKeySize]byte
)
func loadExactHex(dst []byte, src string) error {
diff --git a/src/tai64.go b/src/tai64.go
new file mode 100644
index 0000000..d0d1432
--- /dev/null
+++ b/src/tai64.go
@@ -0,0 +1,23 @@
+package main
+
+import (
+ "encoding/binary"
+ "time"
+)
+
+const (
+ TAI64NBase = uint64(4611686018427387914)
+ TAI64NSize = 12
+)
+
+type TAI64N [TAI64NSize]byte
+
+func Timestamp() TAI64N {
+ var tai64n TAI64N
+ now := time.Now()
+ secs := TAI64NBase + uint64(now.Unix())
+ nano := uint32(now.UnixNano())
+ binary.BigEndian.PutUint64(tai64n[:], secs)
+ binary.BigEndian.PutUint32(tai64n[8:], nano)
+ return tai64n
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-17 13:54:01 +0000