Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/corlib/CommonCrypto/RijndaelManaged.cs

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+//
+// RijndaelManaged.cs: Use CommonCrypto AES when possible, 
+//	fallback on RijndaelManagedTransform otherwise
+//
+// Authors:
+//	Sebastien Pouliot  <sebastien@xamarin.com>
+//
+// Copyright 2012 Xamarin Inc.
+//
+
+using System;
+using System.Security.Cryptography;
+
+using Mono.Security.Cryptography;
+using Crimson.CommonCrypto;
+
+namespace System.Security.Cryptography {
+	
+	public sealed class RijndaelManaged : Rijndael {
+		
+		public RijndaelManaged ()
+		{
+		}
+		
+		public override void GenerateIV ()
+		{
+			IVValue = KeyBuilder.IV (BlockSizeValue >> 3);
+		}
+		
+		public override void GenerateKey ()
+		{
+			KeyValue = KeyBuilder.Key (KeySizeValue >> 3);
+		}
+		
+		public override ICryptoTransform CreateDecryptor (byte[] rgbKey, byte[] rgbIV) 
+		{
+			// AES is Rijndael with a 128 bits block size, so we can use CommonCrypto in this case
+			if (BlockSize == 128) {
+				IntPtr decryptor = IntPtr.Zero;
+				switch (Mode) {
+				case CipherMode.CBC:
+					decryptor = Cryptor.Create (CCOperation.Decrypt, CCAlgorithm.AES128, CCOptions.None, rgbKey, rgbIV);
+					return new FastCryptorTransform (decryptor, this, false, rgbIV);
+				case CipherMode.ECB:
+					decryptor = Cryptor.Create (CCOperation.Decrypt, CCAlgorithm.AES128, CCOptions.ECBMode, rgbKey, rgbIV);
+					return new FastCryptorTransform (decryptor, this, false, rgbIV);
+				default:
+					// CFB cipher mode is not supported by the (old) API we used (for compatibility) so we fallback for them
+					// FIXME: benchmark if we're better with RijndaelManagedTransform or CryptorTransform for CFB mode
+					break;
+				}
+			}
+
+            return NewEncryptor(rgbKey,
+                                ModeValue,
+                                rgbIV,
+                                FeedbackSizeValue,
+                                RijndaelManagedTransformMode.Decrypt);
+		}
+		
+		public override ICryptoTransform CreateEncryptor (byte[] rgbKey, byte[] rgbIV) 
+		{
+			if (BlockSize == 128) {
+				IntPtr encryptor = IntPtr.Zero;
+				switch (Mode) {
+				case CipherMode.CBC:
+					encryptor = Cryptor.Create (CCOperation.Encrypt, CCAlgorithm.AES128, CCOptions.None, rgbKey, rgbIV);
+					return new FastCryptorTransform (encryptor, this, true, rgbIV);
+				case CipherMode.ECB:
+					encryptor = Cryptor.Create (CCOperation.Encrypt, CCAlgorithm.AES128, CCOptions.ECBMode, rgbKey, rgbIV);
+					return new FastCryptorTransform (encryptor, this, true, rgbIV);
+				default:
+					// CFB cipher mode is not supported by the (old) API we used (for compatibility) so we fallback for them
+					// FIXME: benchmark if we're better with RijndaelManagedTransform or CryptorTransform for CFB mode
+					break;
+				}
+			}
+
+            return NewEncryptor(rgbKey,
+                                ModeValue,
+                                rgbIV,
+                                FeedbackSizeValue,
+                                RijndaelManagedTransformMode.Encrypt);
+        }
+
+
+        private ICryptoTransform NewEncryptor (byte[] rgbKey,
+                                               CipherMode mode,
+                                               byte[] rgbIV,
+                                               int feedbackSize,
+                                               RijndaelManagedTransformMode encryptMode) {
+            // Build the key if one does not already exist
+            if (rgbKey == null) {
+                rgbKey = Utils.GenerateRandom(KeySizeValue / 8);
+            }
+
+            // If not ECB mode, make sure we have an IV. In CoreCLR we do not support ECB, so we must have
+            // an IV in all cases.
+#if !FEATURE_CRYPTO
+            if (mode != CipherMode.ECB) {
+#endif // !FEATURE_CRYPTO
+                if (rgbIV == null) {
+                    rgbIV = Utils.GenerateRandom(BlockSizeValue / 8);
+                }
+#if !FEATURE_CRYPTO
+            }
+#endif // !FEATURE_CRYPTO
+
+            // Create the encryptor/decryptor object
+            return new RijndaelManagedTransform (rgbKey,
+                                                 mode,
+                                                 rgbIV,
+                                                 BlockSizeValue,
+                                                 feedbackSize,
+                                                 PaddingValue,
+                                                 encryptMode);
+        }                            
+	}
+}