C#实现3DES加密解密

    /// <summary>
    /// DES3加密解密
    /// </summary>
    public class Des3
    {
        #region CBC模式**

        /// <summary>
        /// DES3 CBC模式加密
        /// </summary>
        /// <param name="key">密钥</param>
        /// <param name="iv">IV</param>
        /// <param name="data">明文的byte数组</param>
        /// <returns>密文的byte数组</returns>
        public static byte[] Des3EncodeCBC( byte[] key, byte[] iv, byte[] data )
        {
            //复制于MSDN

            try
            {
                // Create a MemoryStream.
                MemoryStream mStream = new MemoryStream();

                TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider();
                tdsp.Mode = CipherMode.CBC;             //默认值
                tdsp.Padding = PaddingMode.PKCS7;       //默认值

                // Create a CryptoStream using the MemoryStream 
                // and the passed key and initialization vector (IV).
                CryptoStream cStream = new CryptoStream( mStream,
                    tdsp.CreateEncryptor( key, iv ),
                    CryptoStreamMode.Write );

                // Write the byte array to the crypto stream and flush it.
                cStream.Write( data, 0, data.Length );
                cStream.FlushFinalBlock();

                // Get an array of bytes from the 
                // MemoryStream that holds the 
                // encrypted data.
                byte[] ret = mStream.ToArray();

                // Close the streams.
                cStream.Close();
                mStream.Close();

                // Return the encrypted buffer.
                return ret;
            }
            catch ( CryptographicException e )
            {
                Console.WriteLine( "A Cryptographic error occurred: {0}", e.Message );
                return null;
            }
        }

        /// <summary>
        /// DES3 CBC模式解密
        /// </summary>
        /// <param name="key">密钥</param>
        /// <param name="iv">IV</param>
        /// <param name="data">密文的byte数组</param>
        /// <returns>明文的byte数组</returns>
        public static byte[] Des3DecodeCBC( byte[] key, byte[] iv, byte[] data )
        {
            try
            {
                // Create a new MemoryStream using the passed 
                // array of encrypted data.
                MemoryStream msDecrypt = new MemoryStream( data );

                TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider();
                tdsp.Mode = CipherMode.CBC;
                tdsp.Padding = PaddingMode.PKCS7;

                // Create a CryptoStream using the MemoryStream 
                // and the passed key and initialization vector (IV).
                CryptoStream csDecrypt = new CryptoStream( msDecrypt,
                    tdsp.CreateDecryptor( key, iv ),
                    CryptoStreamMode.Read );

                // Create buffer to hold the decrypted data.
                byte[] fromEncrypt = new byte[data.Length];

                // Read the decrypted data out of the crypto stream
                // and place it into the temporary buffer.
                csDecrypt.Read( fromEncrypt, 0, fromEncrypt.Length );

                //Convert the buffer into a string and return it.
                return fromEncrypt;
            }
            catch ( CryptographicException e )
            {
                Console.WriteLine( "A Cryptographic error occurred: {0}", e.Message );
                return null;
            }
        }

        #endregion

        #region ECB模式

        /// <summary>
        /// DES3 ECB模式加密
        /// </summary>
        /// <param name="key">密钥</param>
        /// <param name="iv">IV(当模式为ECB时，IV无用)</param>
        /// <param name="str">明文的byte数组</param>
        /// <returns>密文的byte数组</returns>
        public static byte[] Des3EncodeECB( byte[] key, byte[] iv, byte[] data )
        {
            try
            {
                // Create a MemoryStream.
                MemoryStream mStream = new MemoryStream();

                TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider();
                tdsp.Mode = CipherMode.ECB;
                tdsp.Padding = PaddingMode.PKCS7;
                // Create a CryptoStream using the MemoryStream 
                // and the passed key and initialization vector (IV).
                CryptoStream cStream = new CryptoStream( mStream,
                    tdsp.CreateEncryptor( key, iv ),
                    CryptoStreamMode.Write );

                // Write the byte array to the crypto stream and flush it.
                cStream.Write( data, 0, data.Length );
                cStream.FlushFinalBlock();

                // Get an array of bytes from the 
                // MemoryStream that holds the 
                // encrypted data.
                byte[] ret = mStream.ToArray();

                // Close the streams.
                cStream.Close();
                mStream.Close();

                // Return the encrypted buffer.
                return ret;
            }
            catch ( CryptographicException e )
            {
                Console.WriteLine( "A Cryptographic error occurred: {0}", e.Message );
                return null;
            }

        }

        /// <summary>
        /// DES3 ECB模式解密
        /// </summary>
        /// <param name="key">密钥</param>
        /// <param name="iv">IV(当模式为ECB时，IV无用)</param>
        /// <param name="str">密文的byte数组</param>
        /// <returns>明文的byte数组</returns>
        public static byte[] Des3DecodeECB( byte[] key, byte[] iv, byte[] data )
        {
            try
            {
                // Create a new MemoryStream using the passed 
                // array of encrypted data.
                MemoryStream msDecrypt = new MemoryStream( data );

                TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider();
                tdsp.Mode = CipherMode.ECB;
                tdsp.Padding = PaddingMode.PKCS7;

                // Create a CryptoStream using the MemoryStream 
                // and the passed key and initialization vector (IV).
                CryptoStream csDecrypt = new CryptoStream( msDecrypt,
                    tdsp.CreateDecryptor( key, iv ),
                    CryptoStreamMode.Read );

                // Create buffer to hold the decrypted data.
                byte[] fromEncrypt = new byte[data.Length];

                // Read the decrypted data out of the crypto stream
                // and place it into the temporary buffer.
                csDecrypt.Read( fromEncrypt, 0, fromEncrypt.Length );

                //Convert the buffer into a string and return it.
                return fromEncrypt;
            }
            catch ( CryptographicException e )
            {
                Console.WriteLine( "A Cryptographic error occurred: {0}", e.Message );
                return null;
            }
        }

        #endregion

        /// <summary>
        /// 类测试
        /// </summary>
        public static void Test()
        {
            System.Text.Encoding utf8 = System.Text.Encoding.UTF8;

            //key为abcdefghijklmnopqrstuvwx的Base64编码
            byte[] key = Convert.FromBase64String( "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4" );
            byte[] iv = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 };      //当模式为ECB时，IV无用
            byte[] data = utf8.GetBytes( "中国ABCabc123" );

            System.Console.WriteLine( "ECB模式:" );
            byte[] str1 = Des3.Des3EncodeECB( key, iv, data );
            byte[] str2 = Des3.Des3DecodeECB( key, iv, str1 );
            System.Console.WriteLine( Convert.ToBase64String( str1 ) );
            System.Console.WriteLine( System.Text.Encoding.UTF8.GetString( str2 ) );

            System.Console.WriteLine();

            System.Console.WriteLine( "CBC模式:" );
            byte[] str3 = Des3.Des3EncodeCBC( key, iv, data );
            byte[] str4 = Des3.Des3DecodeCBC( key, iv, str3 );
            System.Console.WriteLine( Convert.ToBase64String( str3 ) );
            System.Console.WriteLine( utf8.GetString( str4 ) );

            System.Console.WriteLine();

        }

    }