From 45e1575108688eeab34e97a1b313e4974d692eb8 Mon Sep 17 00:00:00 2001
From: defia <defiaq@gmail.com>
Date: Tue, 3 Feb 2015 12:22:18 +0800
Subject: [PATCH 1/3] add support and test for chacha20 encrypt

---
 shadowsocks/encrypt.go      | 11 +++++++++--
 shadowsocks/encrypt_test.go |  9 +++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/shadowsocks/encrypt.go b/shadowsocks/encrypt.go
index 3dbb673..e9a563b 100644
--- a/shadowsocks/encrypt.go
+++ b/shadowsocks/encrypt.go
@@ -2,8 +2,6 @@ package shadowsocks
 
 import (
 	"bytes"
-	"golang.org/x/crypto/blowfish"
-	"golang.org/x/crypto/cast5"
 	"crypto/aes"
 	"crypto/cipher"
 	"crypto/des"
@@ -13,6 +11,10 @@ import (
 	"encoding/binary"
 	"errors"
 	"io"
+
+	"github.com/codahale/chacha20"
+	"golang.org/x/crypto/blowfish"
+	"golang.org/x/crypto/cast5"
 )
 
 var errEmptyPassword = errors.New("empty key")
@@ -137,6 +139,10 @@ func newRC4MD5Stream(key, iv []byte, _ DecOrEnc) (cipher.Stream, error) {
 	return rc4.NewCipher(rc4key)
 }
 
+func newChaCha20Stream(key, iv []byte, _ DecOrEnc) (cipher.Stream, error) {
+	return chacha20.New(key, iv)
+}
+
 type cipherInfo struct {
 	keyLen    int
 	ivLen     int
@@ -153,6 +159,7 @@ var cipherMethod = map[string]*cipherInfo{
 	"rc4-md5":     {16, 16, newRC4MD5Stream},
 	"rc4":         {16, 0, nil},
 	"table":       {16, 0, nil},
+	"chacha20":    {32, 8, newChaCha20Stream},
 }
 
 func CheckCipherMethod(method string) error {
diff --git a/shadowsocks/encrypt_test.go b/shadowsocks/encrypt_test.go
index e9ff06d..e135f64 100644
--- a/shadowsocks/encrypt_test.go
+++ b/shadowsocks/encrypt_test.go
@@ -143,6 +143,10 @@ func TestRC4MD5(t *testing.T) {
 	testBlockCipher(t, "rc4-md5")
 }
 
+func TestChaCha20(t *testing.T) {
+	testBlockCipher(t, "chacha20")
+}
+
 var cipherKey = make([]byte, 64)
 
 func init() {
@@ -200,3 +204,8 @@ func BenchmarkRC4MD5Init(b *testing.B) {
 	ci := cipherMethod["rc4-md5"]
 	benchmarkCipherInit(b, ci)
 }
+
+func BenchmarkChaCha20Init(b *testing.B) {
+	ci := cipherMethod["chacha20"]
+	benchmarkCipherInit(b, ci)
+}

From dcb3b78febd9ee3b54b1a90620c64aad9f119135 Mon Sep 17 00:00:00 2001
From: defia <defiaq@gmail.com>
Date: Tue, 3 Feb 2015 18:37:59 +0800
Subject: [PATCH 2/3] fix travis build failed

---
 .travis.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.travis.yml b/.travis.yml
index c68e325..646aed1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,7 @@ go:
 install:
   - go get golang.org/x/crypto/blowfish
   - go get golang.org/x/crypto/cast5
+  - go get github.com/codahale/chacha20
   - go install ./cmd/shadowsocks-local
   - go install ./cmd/shadowsocks-server
 script:

From 08ad3023b032bc50c1e0566703899c4004837d2d Mon Sep 17 00:00:00 2001
From: defia <defiaq@gmail.com>
Date: Wed, 11 Feb 2015 16:42:16 +0800
Subject: [PATCH 3/3] fix PipeThenClose will read once more when eof occurs

---
 shadowsocks/pipe.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/shadowsocks/pipe.go b/shadowsocks/pipe.go
index 35f356f..9e53bb7 100644
--- a/shadowsocks/pipe.go
+++ b/shadowsocks/pipe.go
@@ -35,7 +35,7 @@ func PipeThenClose(src, dst net.Conn, timeoutOpt int) {
 		// read may return EOF with n > 0
 		// should always process n > 0 bytes before handling error
 		if n > 0 {
-			if _, err = dst.Write(buf[0:n]); err != nil {
+			if _, err := dst.Write(buf[0:n]); err != nil {
 				Debug.Println("write:", err)
 				break
 			}