links: accept unpadded and url-safe base64, legacy ss format #1281

util/base64.go

@@ -1,10 +1,25 @@
 package util
 
-import "encoding/base64"
+import (
+	"encoding/base64"
+	"strings"
+)
+
+func decodeBase64(str string) ([]byte, error) {
+	str = strings.TrimSpace(str)
+	var err error
+	for _, enc := range []*base64.Encoding{base64.StdEncoding, base64.RawStdEncoding, base64.URLEncoding, base64.RawURLEncoding} {
+		var decoded []byte
+		if decoded, err = enc.DecodeString(str); err == nil {
+			return decoded, nil
+		}
+	}
+	return nil, err
+}
 
 // Function to return decoded bytes if a string is Base64 encoded
 func StrOrBase64Encoded(str string) string {
-	decoded, err := base64.StdEncoding.DecodeString(str)
+	decoded, err := decodeBase64(str)
 	if err == nil {
 		return string(decoded)
 	}
@@ -12,7 +27,7 @@ func StrOrBase64Encoded(str string) string {
 }
 
 func B64StrToByte(str string) ([]byte, error) {
-	return base64.StdEncoding.DecodeString(str)
+	return decodeBase64(str)
 }
 
 func ByteToB64Str(b []byte) string {

util/linkToJson.go

@@ -351,6 +351,21 @@ func tuic(u *url.URL, i int) (*map[string]interface{}, string, error) {
 }
 
 func ss(u *url.URL, i int) (*map[string]interface{}, string, error) {
+	if u.User == nil {
+		decoded, err := decodeBase64(u.Host + strings.TrimSuffix(u.Path, "/"))
+		if err != nil {
+			return nil, "", common.NewError("Unsupported shadowsocks")
+		}
+		idx := strings.LastIndex(string(decoded), "@")
+		if idx == -1 {
+			return nil, "", common.NewError("Unsupported shadowsocks")
+		}
+		legacy := *u
+		legacy.User = url.UserPassword(splitMethod(string(decoded[:idx])))
+		legacy.Host = string(decoded[idx+1:])
+		legacy.Path = ""
+		u = &legacy
+	}
 	query, _ := url.ParseQuery(u.RawQuery)
 	host, portStr, _ := net.SplitHostPort(u.Host)
 	port := 443
@@ -410,6 +425,11 @@ func ss(u *url.URL, i int) (*map[string]interface{}, string, error) {
 	return &ss, tag, nil
 }
 
+func splitMethod(userInfo string) (string, string) {
+	method, password, _ := strings.Cut(userInfo, ":")
+	return method, password
+}
+
 func parseNaiveLink(u *url.URL, i int) (*map[string]interface{}, string, error) {
 	var host, portStr, username, password string
 	var port int

util/linkToJson_ss_test.go

@@ -0,0 +1,48 @@
+package util
+
+import (
+	"encoding/base64"
+	"testing"
+)
+
+// Shadowsocks links come base64-encoded in several flavours; strict standard
+// decoding rejected most of them and the node vanished from Clash output,
+// while the link subscription passed the line through untouched (#1281).
+func TestShadowsocksLinkFormats(t *testing.T) {
+	const method = "2022-blake3-aes-256-gcm"
+	const password = "bWFza2VkLXZhbHVlMDAwMDAwMDAwMDAwMDAwMDAwMDA=:bWFza2VkLXZhbHVlMDAwMDAwMDAwMDAwMDAwMDAwMDA="
+	userInfo := method + ":" + password
+
+	cases := map[string]string{
+		"padded standard":   base64.StdEncoding.EncodeToString([]byte(userInfo)) + "@[240e:1:2::1234]:22851",
+		"unpadded url-safe": base64.RawURLEncoding.EncodeToString([]byte(userInfo)) + "@[240e:1:2::1234]:22851",
+		"plugin path":       base64.RawURLEncoding.EncodeToString([]byte(userInfo)) + "@[240e:1:2::1234]:22851/?plugin=none",
+		"legacy whole":      base64.StdEncoding.EncodeToString([]byte(userInfo + "@[240e:1:2::1234]:22851")),
+		"legacy unpadded":   base64.RawURLEncoding.EncodeToString([]byte(userInfo + "@[240e:1:2::1234]:22851")),
+	}
+	for name, body := range cases {
+		t.Run(name, func(t *testing.T) {
+			out, tag, err := GetOutbound("ss://"+body+"#node", 0)
+			if err != nil {
+				t.Fatal(err)
+			}
+			o := *out
+			if tag != "node" || o["method"] != method || o["password"] != password ||
+				o["server"] != "240e:1:2::1234" || o["server_port"] != 22851 {
+				t.Errorf("got %v", o)
+			}
+		})
+	}
+}
+
+// vmess payloads are often unpadded too.
+func TestVmessUnpaddedLink(t *testing.T) {
+	payload := base64.RawStdEncoding.EncodeToString([]byte(`{"v":"2","ps":"vm","add":"1.2.3.4","port":"443","id":"b831381d-6324-4d53-ad4f-8cda48b30811","net":"tcp"}`))
+	out, _, err := GetOutbound("vmess://"+payload, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if (*out)["server"] != "1.2.3.4" {
+		t.Errorf("got %v", *out)
+	}
+}