加密与解密

最近想要对连接字符串加密，就直接想到了加密字符串的方法，如下有示例一个:
先定义一个key与iv

private string key = "GroupPower";
private string iv = "AFaneTi";

再定义一个加密对象

private RijndaelManaged mobjCryptoService = new RijndaelManaged();

然后初始化Key与IV

/// <summary>
        /// 初始化密钥
        /// </summary>
        /// <returns>密钥字节数组</returns>
        private byte[] GetLegalKey()
        {
            string result = "";
            mobjCryptoService.GenerateKey();
            byte[] buff = mobjCryptoService.Key;
            if (key.Length < buff.Length)
            {
                result = key.PadRight(buff.Length, ' ');
            }
            else if (key.Length > buff.Length)
            {
                result = key.Substring(0, buff.Length);
            }
            else
            {
                result = key;
            }
            return Encoding.ASCII.GetBytes(result);
        }  

        /// <summary>
        /// 初始化向量IV
        /// </summary>
        /// <returns>IV向量字节数组</returns>
        private byte[] GetLegalIV()
        {
            string result = "";
            mobjCryptoService.GenerateIV();
            byte[] buff = mobjCryptoService.IV;
            if (iv.Length < buff.Length)
            {
                result = iv.PadRight(buff.Length, ' ');
            }
            else if (iv.Length > buff.Length)
            {
                result = iv.Substring(0, buff.Length);
            }
            else
            {
                result = iv;
            }
            return Encoding.ASCII.GetBytes(result);
        }  

下面是对称加密字符串

/// <summary>
        /// 对称加密字符串
        /// </summary>
        /// <param name="sourceStr">待加密的字符串</param>
        /// <returns>加密后的字符串</returns>
        public string EncryStr(string sourceStr)
        {
            byte[] bytIn = UTF8Encoding.UTF8.GetBytes(sourceStr);
            MemoryStream ms = new MemoryStream();
            mobjCryptoService.Key = GetLegalKey();
            mobjCryptoService.IV = GetLegalIV();
            ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor();
            CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);
            cs.Write(bytIn, 0, bytIn.Length);
            cs.FlushFinalBlock();
            ms.Close();
            byte[] bytOut = ms.ToArray();
            return Convert.ToBase64String(bytOut);
        }

对字符串解密

/// <summary>
        /// 对称解密字符串
        /// </summary>
        /// <param name="sourceStr">密文</param>
        /// <returns>明文</returns>
        public string DecryStr(string sourceStr)
        {
            try
            {
                byte[] bytIn = Convert.FromBase64String(sourceStr);
                MemoryStream ms = new MemoryStream(bytIn, 0, bytIn.Length);
                mobjCryptoService.Key = GetLegalKey();
                mobjCryptoService.IV = GetLegalIV();
                ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor();
                CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);
                StreamReader sr = new StreamReader(cs);
                return sr.ReadToEnd();
            }
            catch
            {
                throw new Exception("源字符串格式不正确");
                return null;
            }
        }