C#对称加密（AES加密）每次生成的密文结果不同思路代码分享

逃离我推掉我的手 2023-10-17 20:34 8阅读 0赞

思路：使用随机向量，把随机向量放入密文中，每次解密时从密文中截取前16位，其实就是我们之前加密的随机向量。

代码

public static string Encrypt(string plainText, string AESKey)
    {
        RijndaelManaged rijndaelCipher = new RijndaelManaged();
        byte[] inputByteArray = Encoding.UTF8.GetBytes(plainText);//得到需要加密的字节数组 
        rijndaelCipher.Key = Convert.FromBase64String(AESKey);//加解密双方约定好密钥：AESKey
        rijndaelCipher.GenerateIV();
        byte[] keyIv = rijndaelCipher.IV;
        byte[] cipherBytes = null;
        using (MemoryStream ms = new MemoryStream())
        {
            using (CryptoStream cs = new CryptoStream(ms, rijndaelCipher.CreateEncryptor(), CryptoStreamMode.Write))
            {
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                cipherBytes = ms.ToArray();//得到加密后的字节数组
                cs.Close();
                ms.Close();
            }
        }
        var allEncrypt = new byte[keyIv.Length + cipherBytes.Length];
        Buffer.BlockCopy(keyIv, 0, allEncrypt, 0, keyIv.Length);
        Buffer.BlockCopy(cipherBytes, 0, allEncrypt, keyIv.Length * sizeof(byte), cipherBytes.Length);
        return Convert.ToBase64String(allEncrypt);
    }
    
    public static string Decrypt(string showText, string AESKey)
    {
        string result = string.Empty;
        try
        {
            byte[] cipherText = Convert.FromBase64String(showText);
            int length = cipherText.Length;
            SymmetricAlgorithm rijndaelCipher = Rijndael.Create();
            rijndaelCipher.Key = Convert.FromBase64String(AESKey);//加解密双方约定好的密钥
            byte[] iv = new byte[16];
            Buffer.BlockCopy(cipherText, 0, iv, 0, 16);
            rijndaelCipher.IV = iv;
            byte[] decryptBytes = new byte[length - 16];
            byte[] passwdText = new byte[length - 16];
            Buffer.BlockCopy(cipherText, 16, passwdText, 0, length - 16);
            using (MemoryStream ms = new MemoryStream(passwdText))
            {
                using (CryptoStream cs = new CryptoStream(ms, rijndaelCipher.CreateDecryptor(), CryptoStreamMode.Read))
                {
                    cs.Read(decryptBytes, 0, decryptBytes.Length);
                    cs.Close();
                    ms.Close();
                }
            }
            result = Encoding.UTF8.GetString(decryptBytes).Replace("\0", "");   ///将字符串后尾的'\0'去掉
        }
        catch { }
        return result;
    }

调用：

string jiaMi = MyAESTools.Encrypt(textBox1.Text, "abcdefgh12345678abcdefgh12345678");
    
    string jieMi = MyAESTools.Decrypt(textBox3.Text, "abcdefgh12345678abcdefgh12345678");