.net 对称加密

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public class CryptoHelper

    {

        // 对称加密算法提供器

        private ICryptoTransform encryptor;//加密器对象

        private ICryptoTransform decryptor;//解密器对象

        private const int BufferSize = 1024;

        public CryptoHelper(String algorithmName, String key)

        {

            SymmetricAlgorithm provider = SymmetricAlgorithm.Create(algorithmName);

            provider.Key = Encoding.UTF8.GetBytes(key);//加密密钥

            provider.IV = new byte[] { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };//偏移量

            encryptor = provider.CreateEncryptor();

            decryptor = provider.CreateDecryptor();

        }

        /// <summary>

        ///  TripleDES 算法 给密钥加密

        /// </summary>

        /// <param name="key"></param>

        public CryptoHelper(string key) : this("TripleDES", key) { }

        /// <summary>

        /// 加密算法

        /// </summary>

        /// <param name="clearText"></param>

        /// <returns></returns>

        public String Encrypt(String clearText)

        {

            //创建明文流

            byte[] clearBuffer = Encoding.UTF8.GetBytes(clearText);

            MemoryStream clearStream = new MemoryStream(clearBuffer);

            MemoryStream encryptedStream = new MemoryStream();

            CryptoStream cryptoStream = new CryptoStream(encryptedStream, encryptor, CryptoStreamMode.Write);

            //将明文流写入到buffer中

            //将buffer中的数据写入到cryptoStream 中

            int bytesRead = 0;

            byte[] buffer = new byte[BufferSize];

            //不能用循环 会执行两次

            //do

            //{

                bytesRead = clearStream.Read(buffer, 0, BufferSize);

                cryptoStream.Write(buffer, 0, BufferSize);

            //} while (bytesRead > 0);

            cryptoStream.FlushFinalBlock();

            //获取加密后的文本

            buffer = encryptedStream.ToArray();

            string encryptedText = Convert.ToBase64String(buffer);

            return encryptedText;

        }

        /// <summary>

        /// 解密算法

        /// </summary>

        /// <param name="encryptedText"></param>

        /// <returns></returns>

        public String Decrypt(String encryptedText)

        {

            byte[] encryptedBuffer = Convert.FromBase64String(encryptedText);

            Stream encryptedStream = new MemoryStream(encryptedBuffer);

            MemoryStream clearStream = new MemoryStream();

            CryptoStream cryptoStream = new CryptoStream(encryptedStream, decryptor, CryptoStreamMode.Read);

            int bytesRead = 0;

            byte[] buffer = new byte[BufferSize];

            //不能用循环 会执行两次

            //do

            //{

                bytesRead = cryptoStream.Read(buffer, 0, BufferSize);

                clearStream.Write(buffer, 0, bytesRead);

            //} while (bytesRead > 0);

            buffer = clearStream.GetBuffer();

            String clearText = Encoding.UTF8.GetString(buffer, 0, (int)clearStream.Length);

            return clearText;

        }

        public static String Encrypt(string clearText, string Key)

        {

            CryptoHelper helper = new CryptoHelper(Key);

            return helper.Encrypt(clearText);

        }

        public static String Decrypt(String encryptedText, String Key)

        {

            CryptoHelper helper = new CryptoHelper(Key);

            return helper.Decrypt(encryptedText);

        }

}

 

前台

 String key = "abcdefghijklmno2";//17位数

            String clearText = "欢迎光临!www.ritztours.com";

            CryptoHelper helper = new CryptoHelper(key);

            String encryptedText = helper.Encrypt(clearText);

String DecryptText = helper.Decrypt(encryptedText);