加解密1-流

加密：

        /// <summary>
        /// 使用指定的加密算法加密流
        /// </summary>
        /// <param name="inStream"></param>
        /// <param name="provider"></param>
        /// <returns>加密后的流</returns>
        public static Stream GetEncryptedStream(Stream inStream, SymmetricAlgorithm provider) 
        {
            MemoryStream outStream = new MemoryStream();
            //以加密方式写入到outStream
            CryptoStream encryptStream = new CryptoStream(outStream, provider.CreateEncryptor(), CryptoStreamMode.Write);

            int numBytes;
            byte[] inputBytes = new byte[1024];
            while ((numBytes = inStream.Read(inputBytes, 0, inputBytes.Length)) != 0)
            {
                encryptStream.Write(inputBytes, 0, numBytes);
            }
            encryptStream.FlushFinalBlock();

            //回到输出的流的起点
            outStream.Position = 0;

            //加密后的数据
            return outStream;
        }


       /// <summary>
        /// 使用指定的加密算法加密流
        /// </summary>
        /// <param name="inStream"></param>
        /// <param name="provider"></param>
        /// <returns>加密后的流</returns>
        public static Stream GetEncryptedStream(Stream inStream, SymmetricAlgorithm provider) 
        {
            MemoryStream outStream = new MemoryStream();
            //以加密方式读取inStream
            CryptoStream encryptStream = new CryptoStream(inStream, provider.CreateEncryptor(), CryptoStreamMode.Read);

            int numBytes;
            byte[] inputBytes = new byte[1024];
            while ((numBytes = encryptStream.Read(inputBytes, 0, inputBytes.Length)) != 0)
            {
                outStream.Write(inputBytes, 0, numBytes);
            }
            //回到输出的流的起点
            outStream.Position = 0;

            //加密后的数据
            return outStream;
        }

解密：

        /// <summary>
        /// 使用指定的算法提供器解密流
        /// </summary>
        /// <param name="inStream"></param>
        /// <param name="provider"></param>
        /// <returns>解密后的流</returns>
        public static Stream GetDecryptedStream(Stream inStream,SymmetricAlgorithm provider)
        {
            MemoryStream outStream = new MemoryStream();
            //以解密方式读取inStream
            CryptoStream decryptStream = new CryptoStream(inStream, provider.CreateDecryptor(), CryptoStreamMode.Read);
            
            int numBytes;
            byte[] inputBytes = new byte[_bufferSize];
            while ((numBytes = decryptStream.Read(inputBytes,0,inputBytes.Length)) !=0)
            {
                outStream.Write(inputBytes, 0, numBytes);
            }

            //回到输出的流的起点
            outStream.Position = 0;

            return outStream;
        }

        /// <summary>
        /// 使用指定的算法提供器解密流
        /// </summary>
        /// <param name="inStream"></param>
        /// <param name="provider"></param>
        /// <returns>解密后的流</returns>
        public static Stream GetDecryptedStream(Stream inStream,SymmetricAlgorithm provider)
        {
            MemoryStream outStream = new MemoryStream();
            //以解密方式写入outStream 
            CryptoStream decryptStream = new CryptoStream(outStream , provider.CreateDecryptor(), CryptoStreamMode.Write);
            
            int numBytes;
            byte[] inputBytes = new byte[_bufferSize];
            while ((numBytes = inStream.Read(inputBytes,0,inputBytes.Length)) !=0)
            {
                decryptStream.Write(inputBytes, 0, numBytes);
            }
            decryptStream.FlushFinalBlock();
            //回到输出的流的起点
            outStream.Position = 0;

            return outStream;
        }