Support Chaha20-Poly1305

cmd/ck-client/ck-client.go

@@ -192,6 +192,12 @@ start:
 			log.Println(err)
 			return
 		}
+	case 0x02:
+		crypto, err = mux.MakeCPCipher(sta.UID)
+		if err != nil {
+			log.Println(err)
+			return
+		}
 	}
 
 	obfs := mux.MakeObfs(sta.UID, crypto)

cmd/ck-server/ck-server.go

@@ -160,7 +160,15 @@ func dispatchConnection(conn net.Conn, sta *server.State) {
 			goWeb(data)
 			return
 		}
+	case 0x02:
+		crypto, err = mux.MakeCPCipher(UID)
+		if err != nil {
+			log.Println(err)
+			goWeb(data)
+			return
+		}
 	default:
+		log.Println("Unknown encryption method")
 		goWeb(data)
 		return
 	}

internal/client/state.go

@@ -112,6 +112,8 @@ func (sta *State) ParseConfig(conf string) (err error) {
 		sta.EncryptionMethod = 0x00
 	case "aes":
 		sta.EncryptionMethod = 0x01
+	case "chacha20-poly1305":
+		sta.EncryptionMethod = 0x02
 	default:
 		return errors.New("Unknown encryption method")
 	}

internal/multiplex/crypto.go

@@ -4,6 +4,7 @@ import (
 	"crypto/aes"
 	"crypto/cipher"
 	"crypto/rand"
+	"golang.org/x/crypto/chacha20poly1305"
 )
 
 type Crypto interface {
@@ -60,3 +61,33 @@ func (a *AES) decrypt(ciphertext []byte, nonce []byte) ([]byte, error) {
 	}
 	return plain, nil
 }
+
+type C20P1305 struct {
+	cipher cipher.AEAD
+}
+
+func MakeCPCipher(key []byte) (*C20P1305, error) {
+	c, err := chacha20poly1305.New(key)
+	if err != nil {
+		return nil, err
+	}
+	ret := C20P1305{
+		c,
+	}
+	return &ret, nil
+}
+
+func (c *C20P1305) encrypt(plaintext []byte, nonce []byte) ([]byte, error) {
+	ciphertext := c.cipher.Seal(nil, nonce, plaintext, nil)
+	ret := make([]byte, len(plaintext)+16)
+	copy(ret, ciphertext)
+	return ret, nil
+}
+
+func (c *C20P1305) decrypt(ciphertext []byte, nonce []byte) ([]byte, error) {
+	plain, err := c.cipher.Open(nil, nonce, ciphertext, nil)
+	if err != nil {
+		return nil, err
+	}
+	return plain, nil
+}

internal/multiplex/obfs.go

@@ -47,6 +47,7 @@ func MakeObfs(key []byte, algo Crypto) Obfser {
 
 		// Composing final obfsed message
 		// We don't use util.AddRecordLayer here to avoid unnecessary malloc
+		// TODO: allocate this in the beginning and do everything in place
 		obfsed := make([]byte, 5+headerLen+len(encryptedPayload))
 		obfsed[0] = 0x17
 		obfsed[1] = 0x03