feat: allow unencoded userinfo as per SIP002

x/config/config_test.go

@@ -121,3 +121,15 @@ func TestParseShadowsocksSIP002URLSuccessful(t *testing.T) {
 	require.Equal(t, "example.com:1234", config.serverAddress)
 	require.Equal(t, "HTTP/1.1 ", string(config.prefix))
 }
+
+func TestParseShadowsocksSIP002URLSuccessfulWithoutEncoding(t *testing.T) {
+	configString := "ss://aes-256-gcm:[email protected]:1234"
+	urls, err := parseConfig(configString)
+	require.NoError(t, err)
+	require.Equal(t, 1, len(urls))
+
+	config, err := parseShadowsocksSIP002URL(urls[0])
+
+	require.NoError(t, err)
+	require.Equal(t, "example.com:1234", config.serverAddress)
+}

x/config/shadowsocks.go

@@ -144,11 +144,14 @@ func parseShadowsocksSIP002URL(url *url.URL) (*shadowsocksConfig, error) {
 		return nil, errors.New("host not specified")
 	}
 	config.serverAddress = url.Host
-	cipherInfoBytes, err := base64.URLEncoding.WithPadding(base64.NoPadding).DecodeString(url.User.String())
-	if err != nil {
-		return nil, fmt.Errorf("failed to decode cipher info [%v]: %w", url.User.String(), err)
-	}
-	cipherName, secret, found := strings.Cut(string(cipherInfoBytes), ":")
+	cipherInfo := url.User.String()
+	// Cipher info can be optionally encoded with Base64URL.
+	encoding := base64.URLEncoding.WithPadding(base64.NoPadding)
+	decodedCipherInfo, err := encoding.DecodeString(cipherInfo)
+	if err == nil && encoding.EncodeToString(decodedCipherInfo) == cipherInfo {
+		cipherInfo = string(decodedCipherInfo)
+	}
+	cipherName, secret, found := strings.Cut(cipherInfo, ":")
 	if !found {
 		return nil, errors.New("invalid cipher info: no ':' separator")
 	}