From 303fd6e26178d9d89e6a7e904d360d939bf6aee0 Mon Sep 17 00:00:00 2001
From: RPRX <63339210+rprx@users.noreply.github.com>
Date: Thu, 28 Jan 2021 03:11:17 +0000
Subject: [PATCH] Standardize Socks Outbound Authentication Behavior

---
 proxy/socks/protocol.go | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/proxy/socks/protocol.go b/proxy/socks/protocol.go
index 5701678e..29b9c913 100644
--- a/proxy/socks/protocol.go
+++ b/proxy/socks/protocol.go
@@ -422,16 +422,6 @@ func ClientHandshake(request *protocol.RequestHeader, reader io.Reader, writer i
 	defer b.Release()
 
 	common.Must2(b.Write([]byte{socks5Version, 0x01, authByte}))
-	if authByte == authPassword {
-		account := request.User.Account.(*Account)
-
-		common.Must(b.WriteByte(0x01))
-		common.Must(b.WriteByte(byte(len(account.Username))))
-		common.Must2(b.WriteString(account.Username))
-		common.Must(b.WriteByte(byte(len(account.Password))))
-		common.Must2(b.WriteString(account.Password))
-	}
-
 	if err := buf.WriteAllBytes(writer, b.Bytes()); err != nil {
 		return nil, err
 	}
@@ -449,6 +439,17 @@ func ClientHandshake(request *protocol.RequestHeader, reader io.Reader, writer i
 	}
 
 	if authByte == authPassword {
+		b.Clear()
+		account := request.User.Account.(*Account)
+		common.Must(b.WriteByte(0x01))
+		common.Must(b.WriteByte(byte(len(account.Username))))
+		common.Must2(b.WriteString(account.Username))
+		common.Must(b.WriteByte(byte(len(account.Password))))
+		common.Must2(b.WriteString(account.Password))
+		if err := buf.WriteAllBytes(writer, b.Bytes()); err != nil {
+			return nil, err
+		}
+
 		b.Clear()
 		if _, err := b.ReadFullFrom(reader, 2); err != nil {
 			return nil, err