From c354852482d6c4e676e46ad134cc508b9305b59b Mon Sep 17 00:00:00 2001
From: Bruce Wayne <admin@bige0.com>
Date: Fri, 26 Feb 2021 15:00:20 +0800
Subject: [PATCH] Better code

Shadowsocks.Protocol
---
 .../Shadowsocks/AeadBlockMessage.cs                 |  8 ++++----
 .../Socks5/Socks5UserPasswordRequestMessage.cs      |  2 +-
 .../Socks5/Socks5VersionIdentifierMessage.cs        |  2 +-
 Shadowsocks.Protocol/Util.cs                        | 13 ++-----------
 4 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/Shadowsocks.Protocol/Shadowsocks/AeadBlockMessage.cs b/Shadowsocks.Protocol/Shadowsocks/AeadBlockMessage.cs
index ffe27bca..e2aa4d5b 100644
--- a/Shadowsocks.Protocol/Shadowsocks/AeadBlockMessage.cs
+++ b/Shadowsocks.Protocol/Shadowsocks/AeadBlockMessage.cs
@@ -31,10 +31,10 @@ namespace Shadowsocks.Protocol.Shadowsocks
             m.Span[0] = (byte)(Data.Length / 256);
             m.Span[1] = (byte)(Data.Length % 256);
             var len1 = aead.Encrypt(nonce.Span, m.Span, buffer.Span);
-            Util.SodiumIncrement(nonce.Span);
+            nonce.Span.SodiumIncrement();
             buffer = buffer.Slice(len1);
             aead.Encrypt(nonce.Span, Data.Span, buffer.Span);
-            Util.SodiumIncrement(nonce.Span);
+            nonce.Span.SodiumIncrement();
             return len;
         }
 
@@ -48,7 +48,7 @@ namespace Shadowsocks.Protocol.Shadowsocks
                 // decrypt length
                 Memory<byte> m = new byte[2];
                 len = aead.Decrypt(nonce.Span, m.Span, buffer.Span);
-                Util.SodiumIncrement(nonce.Span);
+                nonce.Span.SodiumIncrement();
                 if (len != 2) return (false, 0);
 
                 expectedDataLength = m.Span[0] * 256 + m.Span[1];
@@ -61,7 +61,7 @@ namespace Shadowsocks.Protocol.Shadowsocks
             var dataBuffer = buffer.Slice(tagLength + 2);
             Data = new byte[expectedDataLength];
             len = aead.Decrypt(nonce.Span, Data.Span, dataBuffer.Span);
-            Util.SodiumIncrement(nonce.Span);
+            nonce.Span.SodiumIncrement();
             if (len != expectedDataLength) return (false, 0);
             return (true, totalLength);
         }
diff --git a/Shadowsocks.Protocol/Socks5/Socks5UserPasswordRequestMessage.cs b/Shadowsocks.Protocol/Socks5/Socks5UserPasswordRequestMessage.cs
index 22050bb3..79629335 100644
--- a/Shadowsocks.Protocol/Socks5/Socks5UserPasswordRequestMessage.cs
+++ b/Shadowsocks.Protocol/Socks5/Socks5UserPasswordRequestMessage.cs
@@ -41,7 +41,7 @@ namespace Shadowsocks.Protocol.Socks5
             if (ReferenceEquals(this, other)) return true;
             if (other.GetType() != GetType()) return false;
             var msg = (Socks5UserPasswordRequestMessage) other;
-            return Util.MemEqual(User, msg.User) && Util.MemEqual(Password, msg.Password);
+            return User.SequenceEqual(msg.User) && Password.SequenceEqual(msg.Password);
         }
     }
 }
\ No newline at end of file
diff --git a/Shadowsocks.Protocol/Socks5/Socks5VersionIdentifierMessage.cs b/Shadowsocks.Protocol/Socks5/Socks5VersionIdentifierMessage.cs
index 8d1805fe..b3ff91a7 100644
--- a/Shadowsocks.Protocol/Socks5/Socks5VersionIdentifierMessage.cs
+++ b/Shadowsocks.Protocol/Socks5/Socks5VersionIdentifierMessage.cs
@@ -36,7 +36,7 @@ namespace Shadowsocks.Protocol.Socks5
             if (other is null) return false;
             if (ReferenceEquals(this, other)) return true;
             if (other.GetType() != GetType()) return false;
-            return Util.MemEqual(Auth, ((Socks5VersionIdentifierMessage) other).Auth);
+            return Auth.SequenceEqual(((Socks5VersionIdentifierMessage) other).Auth);
         }
     }
 }
\ No newline at end of file
diff --git a/Shadowsocks.Protocol/Util.cs b/Shadowsocks.Protocol/Util.cs
index 89956696..612c61ca 100644
--- a/Shadowsocks.Protocol/Util.cs
+++ b/Shadowsocks.Protocol/Util.cs
@@ -28,18 +28,9 @@ namespace Shadowsocks.Protocol
 
         public static ArgumentException BufferTooSmall(int expected, int actual, string name) => new ArgumentException($"Require {expected} byte buffer, received {actual} byte", name);
 
-        public static bool MemEqual(Memory<byte> m1, Memory<byte> m2)
-        {
-            if (m1.Length != m2.Length) return false;
-            for (var i = 0; i < m1.Length; i++)
-            {
-                if (m1.Span[i] != m2.Span[i]) return false;
-            }
-
-            return true;
-        }
+        public static bool SequenceEqual(this Memory<byte> m1, ReadOnlyMemory<byte> m2) => m1.Span.SequenceEqual(m2.Span);
 
-        public static void SodiumIncrement(Span<byte> salt)
+        public static void SodiumIncrement(this Span<byte> salt)
         {
             for (var i = 0; i < salt.Length; ++i)
             {