C# AES加密类

发布 2021-04-29
更新 2024-01-20
阅读

本文最后更新于$day天前，文中所描述的信息可能已发生改变。

1、序言

各种语言对加密类使用都有极其不太一样的方法，无论是Nodejs、Python、还是C#，加密是要注意原格式编码、Key编码、VI编码。还要注意加密填充方法（Padding），非128位Key填充方法。最优解当然是都是使用byte[]进行操作，这样可以在各种语言上做到一个统一。好像自MD5以后，我还没发现有什么语言可以直接一个 MD5(参数)，能直接生成Hash或者密文。

2、类的作用

这个类可以用不长于32位为UTF-8字符进行AES加密，会自动用空格填充不足32位字符。加密方法使用ECB，这个是一个不需要向量的方法。密文填充方式用PKCS7。可以使用文字加密、JSON文本加密，或者加密Byte[]。

3、源代码

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace Utils
{
    public static class AES
    {
        public const string AesKey = "AES";
        /// <summary>
        /// 文字解密返回UTF8字符
        /// </summary>
        /// <param name="Data"></param>
        /// <param name="Key"></param>
        /// <returns></returns>
        public static string AESDecrypt(String Data, String Key = AesKey)
        {
            return Encoding.UTF8.GetString(AESDecrypt(Convert.FromBase64String(Data), Key));

        }
        /// <summary>
        /// 文字加密，返回Base64编码
        /// </summary>
        /// <param name="Data"></param>
        /// <param name="Key"></param>
        /// <returns></returns>
        public static string AESEncrypt(String Data, String Key = AesKey)
        {
            return Convert.ToBase64String(AESEncrypt(Encoding.UTF8.GetBytes(Data), Key));
        }

        public static byte[] AESEncrypt(byte[] Data, String Key = AesKey)
        {
            MemoryStream mStream = new MemoryStream();
            RijndaelManaged aes = new RijndaelManaged();

            byte[] plainBytes = Data;
            Byte[] bKey = new Byte[32];
            Array.Copy(Encoding.UTF8.GetBytes(Key.PadRight(bKey.Length)), bKey, bKey.Length);
            aes.Mode = CipherMode.ECB;
            aes.Padding = PaddingMode.PKCS7;
            aes.KeySize = 128;  
            aes.Key = bKey;
            CryptoStream cryptoStream = new CryptoStream(mStream, aes.CreateEncryptor(), CryptoStreamMode.Write);
            try
            {
                cryptoStream.Write(plainBytes, 0, plainBytes.Length);
                cryptoStream.FlushFinalBlock();
                return mStream.ToArray();
            }
            finally
            {
                cryptoStream.Close();
                mStream.Close();
                aes.Clear();
            }
      
        }

        public static byte[] AESDecrypt(byte[] Data, String Key = AesKey)
        {
            Byte[] encryptedBytes = Data;
            Byte[] bKey = new Byte[32];
            Array.Copy(Encoding.UTF8.GetBytes(Key.PadRight(bKey.Length)), bKey, bKey.Length);
            MemoryStream mStream = new MemoryStream(encryptedBytes);
            RijndaelManaged aes = new RijndaelManaged();
            aes.Mode = CipherMode.ECB;
            aes.Padding = PaddingMode.PKCS7;
            aes.KeySize = 128;
            aes.Key = bKey;
            CryptoStream cryptoStream = new CryptoStream(mStream, aes.CreateDecryptor(), CryptoStreamMode.Read);
            try
            {
                byte[] tmp = new byte[encryptedBytes.Length + 32];
                int len = cryptoStream.Read(tmp, 0, encryptedBytes.Length + 32);
                byte[] ret = new byte[len];
                Array.Copy(tmp, 0, ret, 0, len);
                return ret;
            }
            finally
            {
                cryptoStream.Close();
                mStream.Close();
                aes.Clear();
            }
        }
    }
}