Update AesUtils.cs

v2rayN/ServiceLib/Common/AesUtils.cs

@@ -1,5 +1,3 @@
-using System;
-using System.IO;
 using System.Security.Cryptography;
 using System.Text;
 
@@ -10,10 +8,8 @@ namespace ServiceLib.Common
         private const int KeySize = 256; // AES-256
         private const int IvSize = 16;   // AES block size
         private const int Iterations = 10000;
-
         private static readonly byte[] Salt = Encoding.ASCII.GetBytes("saltysalt".PadRight(16, ' ')); // google浏览器默认盐值
-
-        private static readonly string DefaultPassword =Utils.GetHomePath() + "AesUtils";
+        private static readonly string DefaultPassword = Utils.GetMd5(Utils.GetHomePath() + "AesUtils");
 
         /// <summary>
         /// Encrypt
@@ -21,34 +17,30 @@ namespace ServiceLib.Common
         /// <param name="text">Plain text</param>
         /// <param name="password">Password for key derivation or direct key in ASCII bytes</param>
         /// <returns>Base64 encoded cipher text with IV</returns>
-        public static string Encrypt(string text, string password = null)
+        public static string Encrypt(string text, string? password = null)
         {
             if (string.IsNullOrEmpty(text))
                 return string.Empty;
 
-            byte[] plaintext = Encoding.UTF8.GetBytes(text);
-            byte[] key = GetKey(password);
-            byte[] iv = GenerateIv();
+            var plaintext = Encoding.UTF8.GetBytes(text);
+            var key = GetKey(password);
+            var iv = GenerateIv();
 
-            using (Aes aes = Aes.Create())
+            using var aes = Aes.Create();
+            aes.Key = key;
+            aes.IV = iv;
+
+            using var ms = new MemoryStream();
+            ms.Write(iv, 0, iv.Length);
+
+            using (var cs = new CryptoStream(ms, aes.CreateEncryptor(), CryptoStreamMode.Write))
             {
-                aes.Key = key;
-                aes.IV = iv;
-
-                using (MemoryStream ms = new MemoryStream())
-                {
-                    ms.Write(iv, 0, iv.Length);
-
-                    using (CryptoStream cs = new CryptoStream(ms, aes.CreateEncryptor(), CryptoStreamMode.Write))
-                    {
-                        cs.Write(plaintext, 0, plaintext.Length);
-                        cs.FlushFinalBlock();
-                    }
-
-                    byte[] cipherTextWithIv = ms.ToArray();
-                    return Convert.ToBase64String(cipherTextWithIv);
-                }
+                cs.Write(plaintext, 0, plaintext.Length);
+                cs.FlushFinalBlock();
             }
+
+            var cipherTextWithIv = ms.ToArray();
+            return Convert.ToBase64String(cipherTextWithIv);
         }
 
         /// <summary>
@@ -57,72 +49,53 @@ namespace ServiceLib.Common
         /// <param name="cipherTextWithIv">Base64 encoded cipher text with IV</param>
         /// <param name="password">Password for key derivation or direct key in ASCII bytes</param>
         /// <returns>Plain text</returns>
-        public static string Decrypt(string cipherTextWithIv, string password = null)
+        public static string Decrypt(string cipherTextWithIv, string? password = null)
         {
             if (string.IsNullOrEmpty(cipherTextWithIv))
                 return string.Empty;
 
-            byte[] cipherTextWithIvBytes = Convert.FromBase64String(cipherTextWithIv);
-            byte[] key = GetKey(password);
+            var cipherTextWithIvBytes = Convert.FromBase64String(cipherTextWithIv);
+            var key = GetKey(password);
 
-            byte[] iv = new byte[IvSize];
+            var iv = new byte[IvSize];
             Buffer.BlockCopy(cipherTextWithIvBytes, 0, iv, 0, IvSize);
 
-            byte[] cipherText = new byte[cipherTextWithIvBytes.Length - IvSize];
+            var cipherText = new byte[cipherTextWithIvBytes.Length - IvSize];
             Buffer.BlockCopy(cipherTextWithIvBytes, IvSize, cipherText, 0, cipherText.Length);
 
-            using (Aes aes = Aes.Create())
+            using var aes = Aes.Create();
+            aes.Key = key;
+            aes.IV = iv;
+
+            using var ms = new MemoryStream();
+            using (var cs = new CryptoStream(ms, aes.CreateDecryptor(), CryptoStreamMode.Write))
             {
-                aes.Key = key;
-                aes.IV = iv;
-
-                using (MemoryStream ms = new MemoryStream())
-                {
-                    using (CryptoStream cs = new CryptoStream(ms, aes.CreateDecryptor(), CryptoStreamMode.Write))
-                    {
-                        cs.Write(cipherText, 0, cipherText.Length);
-                        cs.FlushFinalBlock();
-                    }
-
-                    byte[] plainText = ms.ToArray();
-                    return Encoding.UTF8.GetString(plainText);
-                }
+                cs.Write(cipherText, 0, cipherText.Length);
+                cs.FlushFinalBlock();
             }
+
+            var plainText = ms.ToArray();
+            return Encoding.UTF8.GetString(plainText);
         }
 
-        private static byte[] GetKey(string password)
+        private static byte[] GetKey(string? password)
         {
-            if (string.IsNullOrEmpty(password))
+            if (password.IsNullOrEmpty())
             {
-                return GetDefaultKey();
+                password = DefaultPassword;
             }
-            else
-            {
-                byte[] key = Encoding.ASCII.GetBytes(password);
-                if (key.Length != KeySize / 8)
-                {
-                    throw new ArgumentException($"Password bytes length must be {KeySize / 8} bytes.");
-                }
-                return key;
-            }
-        }
 
-        private static byte[] GetDefaultKey()
-        {
-            using (Rfc2898DeriveBytes pbkdf2 = new Rfc2898DeriveBytes(DefaultPassword, Salt, Iterations, HashAlgorithmName.SHA256))
-            {
-                return pbkdf2.GetBytes(KeySize / 8);
-            }
+            using var pbkdf2 = new Rfc2898DeriveBytes(password, Salt, Iterations, HashAlgorithmName.SHA256);
+            return pbkdf2.GetBytes(KeySize / 8);
         }
 
         private static byte[] GenerateIv()
         {
-            using (RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider())
-            {
-                byte[] iv = new byte[IvSize];
-                rng.GetBytes(iv);
-                return iv;
-            }
+            var randomNumber = new byte[IvSize];
+
+            using var rng = RandomNumberGenerator.Create();
+            rng.GetBytes(randomNumber);
+            return randomNumber;
         }
     }
 }