C#之常用加解密

加解密在数据传输中尤为重要，其加密解密的方式也有很多种，我这个类目前只总结了几个常用的，后续用到时会继续完善添加

    public static class JSCSecurityTool
    {
        #region AES加解密
        //默认密钥向量
        private static byte[] Keys = { 0x41, 0x72, 0x65, 0x79, 0x6F, 0x75, 0x6D, 0x79, 0x53, 0x6E, 0x6F, 0x77, 0x6D, 0x61, 0x6E, 0x3F };

        /// <summary>
        /// 对称加密算法AES(块式加密算法)
        /// </summary>
        /// <param name="encryptString">待加密字符串</param>
        /// <param name="encryptKey">加密密钥，须半角字符</param>
        /// <param name="mode">加密模式</param>
        /// <returns>加密结果字符串</returns>
        public static string AESEncrypt(string encryptString, string encryptKey, CipherMode mode = CipherMode.CBC)
        {
            encryptKey = GetSHA256Hash(encryptKey);
            var aes = Aes.Create();
            aes.Key = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 32));
            aes.IV = Keys;
            aes.Mode = mode;
            var rijndaelEncrypt = aes.CreateEncryptor();
            byte[] inputData = Encoding.UTF8.GetBytes(encryptString);
            byte[] encryptedData = rijndaelEncrypt.TransformFinalBlock(inputData, 0, inputData.Length);
            return Convert.ToBase64String(encryptedData);
        }

        /// <summary>
        /// 对称加密算法AES解密字符串
        /// </summary>
        /// <param name="decryptString">待解密的字符串</param>
        /// <param name="decryptKey">解密密钥,和加密密钥相同</param>
        /// <param name="mode">加密模式</param>
        /// <returns>解密成功返回解密后的字符串,失败返回空</returns>
        public static string AESDecrypt(string decryptString, string decryptKey, CipherMode mode = CipherMode.CBC)
        {
            try
            {
                decryptKey = GetSHA256Hash(decryptKey);
                var aes = Aes.Create("AesManaged");
                aes.Key = Encoding.UTF8.GetBytes(decryptKey);
                aes.IV = Keys;
                aes.Mode = mode;
                ICryptoTransform rijndaelDecrypt = aes.CreateDecryptor();
                byte[] inputData = Convert.FromBase64String(decryptString);
                byte[] decryptedData = rijndaelDecrypt.TransformFinalBlock(inputData, 0, inputData.Length);
                return Encoding.UTF8.GetString(decryptedData);
            }
            catch
            {
                return string.Empty;
            }
        }

        // 使用SHA-256哈希函数处理秘钥
        private static string GetSHA256Hash(string input)
        {
            using (SHA256 sha256 = System.Security.Cryptography.SHA256.Create())
            {
                byte[] inputBytes = Encoding.UTF8.GetBytes(input);
                byte[] hashedBytes = sha256.ComputeHash(inputBytes);
                // 取前32字节作为AES算法的秘钥
                return Convert.ToBase64String(hashedBytes).Substring(0, 32);
            }
        }
        #endregion

        #region Base64加密解密
        /// <summary>
        /// Base64加密
        /// </summary>
        /// <param name="str">需要加密的字符串</param>
        /// <returns>加密后的数据</returns>
        public static string Base64Encrypt(string str)
        {
            try
            {
                byte[] encbuff = Encoding.UTF8.GetBytes(str);
                return Convert.ToBase64String(encbuff);
            }
            catch
            {
                return str;
            }
        }

        /// <summary>
        /// Base64解密
        /// </summary>
        /// <param name="str">需要解密的字符串</param>
        /// <returns>解密后的数据</returns>
        public static string Base64Decrypt(string str)
        {
            try
            {
                byte[] decbuff = Convert.FromBase64String(str);
                return Encoding.UTF8.GetString(decbuff);
            }
            catch
            {
                return str;
            }
        }
        #endregion

        #region MD5加密
        /// <summary>
        ///     对字符串进行MD5摘要
        /// </summary>
        /// <param name="str">需要摘要的字符串</param>
        /// <returns>MD5摘要字符串</returns>
        public static string MD5Encrypt(string str)
        {
            MD5CryptoServiceProvider md5Hasher = new MD5CryptoServiceProvider();
            byte[] hashedDataBytes;
            hashedDataBytes = md5Hasher.ComputeHash(Encoding.GetEncoding("gb2312").GetBytes(str));
            StringBuilder byte2String = new StringBuilder();
            foreach (byte i in hashedDataBytes)
            {
                byte2String.Append(i.ToString("x2"));
            }
            return byte2String.ToString();
        }
        #endregion

        #region SHA256加密
        /// <summary>
        /// SHA256函数
        /// </summary>
        /// <param name="str">原始字符串</param>
        /// <returns>SHA256结果(返回长度为44字节的字符串),SHA256的输出长度固定为256位</returns>
        public static string SHA256EncryptBase64(string str)
        {
            byte[] sha256Data = Encoding.UTF8.GetBytes(str);
            using (var sha256 = SHA256.Create())
            {
                byte[] result = sha256.ComputeHash(sha256Data);
                return Convert.ToBase64String(result); //返回长度为44字节的字符串
            }
        }

        /// <summary>
        /// SHA256函数
        /// </summary>
        /// <param name="str"></param>
        /// <returns>SHA256结果(十六进制字符串)</returns>
        public static string SHA256EncryptHex(string str)
        {
            //使用 SHA256 加密算法：
            SHA256 sha256 = new SHA256Managed();
            byte[] sha256Bytes = Encoding.Default.GetBytes(str);
            byte[] cryString = sha256.ComputeHash(sha256Bytes);
            string sha256Str = string.Empty;
            for (int i = 0; i < cryString.Length; i++)
            {
                sha256Str += cryString[i].ToString("X2");
            }
            return sha256Str;
        }
        #endregion
    }