Moved ciphers to core and simplified import graph

README.md

@@ -16,7 +16,7 @@ GoDoc at https://godoc.org/github.com/riobard/go-shadowsocks2/
 ## Install
 
 ```sh
-go get github.com/riobard/go-shadowsocks2
+go get -u -v github.com/riobard/go-shadowsocks2
 ```
 
 

cipher.go → core/cipher.go

@@ -1,4 +1,4 @@
-package main
+package core
 
 import (
 	"crypto/md5"
@@ -7,12 +7,25 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/riobard/go-shadowsocks2/core"
 	"github.com/riobard/go-shadowsocks2/shadowaead"
 	"github.com/riobard/go-shadowsocks2/shadowstream"
 )
 
-var errCipherNotSupported = errors.New("ciper not supported")
+type Cipher interface {
+	StreamConnCipher
+	PacketConnCipher
+}
+
+type StreamConnCipher interface {
+	StreamConn(net.Conn) net.Conn
+}
+
+type PacketConnCipher interface {
+	PacketConn(net.PacketConn) net.PacketConn
+}
+
+// ErrCipherNotSupported occurs when a cipher is not supported (likely because of security concerns).
+var ErrCipherNotSupported = errors.New("cipher not supported")
 
 // List of AEAD ciphers: key size in bytes and constructor
 var aeadList = map[string]struct {
@@ -39,8 +52,8 @@ var streamList = map[string]struct {
 	"chacha20-ietf": {32, shadowstream.Chacha20IETF},
 }
 
-// listCipher returns a list of available cipher names sorted alphabetically.
-func listCipher() []string {
+// ListCipher returns a list of available cipher names sorted alphabetically.
+func ListCipher() []string {
 	var l []string
 	for k := range aeadList {
 		l = append(l, k)
@@ -52,8 +65,8 @@ func listCipher() []string {
 	return l
 }
 
-// derive key from password if given key is empty
-func pickCipher(name string, key []byte, password string) (core.Cipher, error) {
+// PickCipher returns a Cipher of the given name. Derive key from password if given key is empty.
+func PickCipher(name string, key []byte, password string) (Cipher, error) {
 	name = strings.ToLower(name)
 
 	if name == "dummy" {
@@ -82,7 +95,7 @@ func pickCipher(name string, key []byte, password string) (core.Cipher, error) {
 		return &streamCipher{ciph}, err
 	}
 
-	return nil, errCipherNotSupported
+	return nil, ErrCipherNotSupported
 }
 
 type aeadCipher struct{ shadowaead.Cipher }

core/doc.go

@@ -1,19 +1,2 @@
-// Package core provides essential interfaces for Shadowsocks
+// Package core implements essential parts of Shadowsocks
 package core
-
-import (
-	"net"
-)
-
-type Cipher interface {
-	StreamConnCipher
-	PacketConnCipher
-}
-
-type StreamConnCipher interface {
-	StreamConn(net.Conn) net.Conn
-}
-
-type PacketConnCipher interface {
-	PacketConn(net.PacketConn) net.PacketConn
-}

main.go

@@ -12,6 +12,8 @@ import (
 	"strings"
 	"syscall"
 	"time"
+
+	"github.com/riobard/go-shadowsocks2/core"
 )
 
 var config struct {
@@ -42,7 +44,7 @@ func main() {
 	}
 
 	flag.BoolVar(&config.Verbose, "verbose", false, "verbose mode")
-	flag.StringVar(&flags.Cipher, "cipher", "chacha20-ietf-poly1305", "available ciphers: "+strings.Join(listCipher(), " "))
+	flag.StringVar(&flags.Cipher, "cipher", "chacha20-ietf-poly1305", "available ciphers: "+strings.Join(core.ListCipher(), " "))
 	flag.StringVar(&flags.Key, "key", "", "base64url-encoded key (derive from password if empty)")
 	flag.IntVar(&flags.Keygen, "keygen", 0, "generate a base64url-encoded random key of given length in byte")
 	flag.StringVar(&flags.Password, "password", "", "password")
@@ -77,7 +79,7 @@ func main() {
 		key = k
 	}
 
-	ciph, err := pickCipher(flags.Cipher, key, flags.Password)
+	ciph, err := core.PickCipher(flags.Cipher, key, flags.Password)
 	if err != nil {
 		log.Fatal(err)
 	}