use extension members for CryptoAbstractions

Author: mus65

src/Renci.SshNet/Abstractions/CryptoAbstraction.cs

@@ -10,77 +10,5 @@ internal static class CryptoAbstraction
         private static readonly RandomNumberGenerator Randomizer = RandomNumberGenerator.Create();
 
         internal static readonly SecureRandom SecureRandom = new SecureRandom(new CryptoApiRandomGenerator(Randomizer));
-
-        /// <summary>
-        /// Generates a <see cref="byte"/> array of the specified length, and fills it with a
-        /// cryptographically strong random sequence of values.
-        /// </summary>
-        /// <param name="length">The length of the array generate.</param>
-        public static byte[] GenerateRandom(int length)
-        {
-            var random = new byte[length];
-            Randomizer.GetBytes(random);
-            return random;
-        }
-
-        public static byte[] HashMD5(byte[] source)
-        {
-#if NET
-            return MD5.HashData(source);
-#else
-            using (var md5 = MD5.Create())
-            {
-                return md5.ComputeHash(source);
-            }
-#endif
-        }
-
-        public static byte[] HashSHA1(byte[] source)
-        {
-#if NET
-            return SHA1.HashData(source);
-#else
-            using (var sha1 = SHA1.Create())
-            {
-                return sha1.ComputeHash(source);
-            }
-#endif
-        }
-
-        public static byte[] HashSHA256(byte[] source)
-        {
-#if NET
-            return SHA256.HashData(source);
-#else
-            using (var sha256 = SHA256.Create())
-            {
-                return sha256.ComputeHash(source);
-            }
-#endif
-        }
-
-        public static byte[] HashSHA384(byte[] source)
-        {
-#if NET
-            return SHA384.HashData(source);
-#else
-            using (var sha384 = SHA384.Create())
-            {
-                return sha384.ComputeHash(source);
-            }
-#endif
-        }
-
-        public static byte[] HashSHA512(byte[] source)
-        {
-#if NET
-            return SHA512.HashData(source);
-#else
-            using (var sha512 = SHA512.Create())
-            {
-                return sha512.ComputeHash(source);
-            }
-#endif
-        }
     }
 }

src/Renci.SshNet/Abstractions/MD5Extensions.cs

@@ -0,0 +1,19 @@
+#nullable enable
+namespace System.Security.Cryptography
+{
+    internal static class MD5Extensions
+    {
+        extension(MD5)
+        {
+#if !NET
+            public static byte[] HashData(byte[] source)
+            {
+                using (var md5 = MD5.Create())
+                {
+                    return md5.ComputeHash(source);
+                }
+            }
+#endif
+        }
+    }
+}

src/Renci.SshNet/Abstractions/RandomNumberGeneratorExtensions.cs

@@ -0,0 +1,22 @@
+#nullable enable
+namespace System.Security.Cryptography
+{
+    internal static class RandomNumberGeneratorExtensions
+    {
+#if !NET
+        private static readonly RandomNumberGenerator Randomizer = RandomNumberGenerator.Create();
+#endif
+
+        extension(RandomNumberGenerator)
+        {
+#if !NET
+            public static byte[] GetBytes(int length)
+            {
+                var random = new byte[length];
+                Randomizer.GetBytes(random);
+                return random;
+            }
+#endif
+        }
+    }
+}

src/Renci.SshNet/Abstractions/SHA1Extensions.cs

@@ -0,0 +1,18 @@
+namespace System.Security.Cryptography
+{
+    internal static class SHA1Extensions
+    {
+        extension(SHA1)
+        {
+#if !NET
+            public static byte[] HashData(byte[] source)
+            {
+                using (var sha1 = SHA1.Create())
+                {
+                    return sha1.ComputeHash(source);
+                }
+            }
+#endif
+        }
+    }
+}

src/Renci.SshNet/Abstractions/SHA256Extensions.cs

@@ -0,0 +1,19 @@
+#nullable enable
+namespace System.Security.Cryptography
+{
+    internal static class SHA256Extensions
+    {
+        extension(SHA256)
+        {
+#if !NET
+            public static byte[] HashData(byte[] source)
+            {
+                using (var sha256 = SHA256.Create())
+                {
+                    return sha256.ComputeHash(source);
+                }
+            }
+#endif
+        }
+    }
+}

src/Renci.SshNet/Abstractions/SHA384Extensions.cs

@@ -0,0 +1,19 @@
+#nullable enable
+namespace System.Security.Cryptography
+{
+    internal static class SHA384Extensions
+    {
+        extension(SHA384)
+        {
+#if !NET
+            public static byte[] HashData(byte[] source)
+            {
+                using (var sha384 = SHA384.Create())
+                {
+                    return sha384.ComputeHash(source);
+                }
+            }
+#endif
+        }
+    }
+}

src/Renci.SshNet/Abstractions/SHA512Extensions.cs

@@ -0,0 +1,19 @@
+#nullable enable
+namespace System.Security.Cryptography
+{
+    internal static class SHA512Extensions
+    {
+        extension(SHA512)
+        {
+#if !NET
+            public static byte[] HashData(byte[] source)
+            {
+                using (var sha512 = SHA512.Create())
+                {
+                    return sha512.ComputeHash(source);
+                }
+            }
+#endif
+        }
+    }
+}

src/Renci.SshNet/Common/HostKeyEventArgs.cs

@@ -1,7 +1,7 @@
 #nullable enable
 using System;
+using System.Security.Cryptography;
 
-using Renci.SshNet.Abstractions;
 using Renci.SshNet.Security;
 
 namespace Renci.SshNet.Common
@@ -104,9 +104,9 @@ public HostKeyEventArgs(KeyHostAlgorithm host)
             HostKeyName = host.Name;
             KeyLength = host.Key.KeyLength;
 
-            _lazyFingerPrint = new Lazy<byte[]>(() => CryptoAbstraction.HashMD5(HostKey));
+            _lazyFingerPrint = new Lazy<byte[]>(() => MD5.HashData(HostKey));
 
-            _lazyFingerPrintSHA256 = new Lazy<string>(() => Convert.ToBase64String(CryptoAbstraction.HashSHA256(HostKey)).TrimEnd('='));
+            _lazyFingerPrintSHA256 = new Lazy<string>(() => Convert.ToBase64String(SHA256.HashData(HostKey)).TrimEnd('='));
 
             _lazyFingerPrintMD5 = new Lazy<string>(() =>
                 {

src/Renci.SshNet/Messages/Message.cs

@@ -1,6 +1,6 @@
 using System.IO;
+using System.Security.Cryptography;
 
-using Renci.SshNet.Abstractions;
 using Renci.SshNet.Common;
 using Renci.SshNet.Compression;
 
@@ -83,7 +83,7 @@ internal byte[] GetPacket(byte paddingMultiplier, Compressor compressor, bool ex
                     var paddingLength = GetPaddingLength(paddingMultiplier, excludePacketLengthFieldWhenPadding ? packetLength - 4 : packetLength);
 
                     // add padding bytes
-                    var paddingBytes = CryptoAbstraction.GenerateRandom(paddingLength);
+                    var paddingBytes = RandomNumberGenerator.GetBytes(paddingLength);
                     sshDataStream.Write(paddingBytes, 0, paddingLength);
 
                     var packetDataLength = GetPacketDataLength(messageLength, paddingLength);
@@ -127,7 +127,7 @@ internal byte[] GetPacket(byte paddingMultiplier, Compressor compressor, bool ex
                     WriteBytes(sshDataStream);
 
                     // add padding bytes
-                    var paddingBytes = CryptoAbstraction.GenerateRandom(paddingLength);
+                    var paddingBytes = RandomNumberGenerator.GetBytes(paddingLength);
                     sshDataStream.Write(paddingBytes, 0, paddingLength);
 
                     return sshDataStream.ToArray();

src/Renci.SshNet/Messages/Transport/KeyExchangeInitMessage.cs

@@ -1,4 +1,4 @@
-using Renci.SshNet.Abstractions;
+using System.Security.Cryptography;
 
 namespace Renci.SshNet.Messages.Transport
 {
@@ -12,7 +12,7 @@ public class KeyExchangeInitMessage : Message, IKeyExchangedAllowed
         /// </summary>
         public KeyExchangeInitMessage()
         {
-            Cookie = CryptoAbstraction.GenerateRandom(16);
+            Cookie = RandomNumberGenerator.GetBytes(16);
         }
 
         #region Message Properties