RijndaelManaged.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / clr / src / BCL / System / Security / Cryptography / RijndaelManaged.cs / 1305376 / RijndaelManaged.cs
                        

                        
                            using System.Diagnostics.Contracts; 
// ==++==
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// ==--==
// [....] 
// 

// 
// RijndaelManaged.cs
//

namespace System.Security.Cryptography 
{
[System.Runtime.InteropServices.ComVisible(true)] 
    public sealed class RijndaelManaged : Rijndael { 
        public RijndaelManaged () {
#if FEATURE_CRYPTO 
            if (CryptoConfig.AllowOnlyFipsAlgorithms)
                throw new InvalidOperationException(Environment.GetResourceString("Cryptography_NonCompliantFIPSAlgorithm"));
            Contract.EndContractBlock();
#endif // FEATURE_CRYPTO 
        }
 
        // #CoreCLRRijndaelModes 
        //
        // On CoreCLR we limit the supported cipher modes and padding modes for the AES algorithm to a 
        // single hard coded value.  This allows us to remove a lot of code by removing support for the
        // uncommon cases and forcing everyone to use the same common padding and ciper modes:
        //
        //  - CipherMode: CipherMode.CBC 
        //  - PaddingMode: PaddingMode.PKCS7
 
        public override ICryptoTransform CreateEncryptor (byte[] rgbKey, byte[] rgbIV) { 
            return NewEncryptor(rgbKey,
                                ModeValue, 
                                rgbIV,
                                FeedbackSizeValue,
                                RijndaelManagedTransformMode.Encrypt);
        } 

        public override ICryptoTransform CreateDecryptor (byte[] rgbKey, byte[] rgbIV) { 
            return NewEncryptor(rgbKey, 
                                ModeValue,
                                rgbIV, 
                                FeedbackSizeValue,
                                RijndaelManagedTransformMode.Decrypt);
        }
 
        public override void GenerateKey () {
            KeyValue = Utils.GenerateRandom(KeySizeValue / 8); 
        } 

        public override void GenerateIV () { 
            IVValue = Utils.GenerateRandom(BlockSizeValue / 8);
        }

        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); 
        } 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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