AES 加解密,MD5加密。

aes 加密，生成公私钥有比较麻烦，可以通过支付宝提供的网站生成。https://miniu.alipay.com/keytool/create。

AES 加解密两种写法：

 /// <summary>
        /// AES 加密
        /// </summary>
        /// <param name="text"></param>
        /// <param name="password"></param>
        /// <param name="iv"></param>
        /// <returns></returns>
        public static string AESEncrypt(string text, string password, string iv)
        {
            RijndaelManaged rijndaelCipher = new RijndaelManaged();
            rijndaelCipher.Mode = CipherMode.CBC;
            rijndaelCipher.Padding = PaddingMode.PKCS7;
            rijndaelCipher.KeySize = 128;
            rijndaelCipher.BlockSize = 128;
            byte[] encryptedData = Encoding.UTF8.GetBytes(text);
            byte[] pwdBytes = System.Text.Encoding.UTF8.GetBytes(password);
            byte[] keyBytes = new byte[16];
            int len = pwdBytes.Length;
            if (len > keyBytes.Length) len = keyBytes.Length;
            System.Array.Copy(pwdBytes, keyBytes, len);
　　　　　　　　//此句如果没有要求，也可以不要。
            rijndaelCipher.IV = new byte[16];
            rijndaelCipher.Key = keyBytes;
            byte[] ivBytes = System.Text.Encoding.UTF8.GetBytes(iv);
            rijndaelCipher.IV = ivBytes;
            ICryptoTransform transform = rijndaelCipher.CreateEncryptor();
            byte[] plainText = transform.TransformFinalBlock(encryptedData, 0, encryptedData.Length);
            return Convert.ToBase64String(plainText);
        }

        /// <summary>
        /// AES解密
        /// </summary>
        /// <param name="text"></param>
        /// <param name="password"></param>
        /// <param name="iv"></param>
        /// <returns></returns>
        public static string AESDecrypt(string text, string password, string iv)
        {
            RijndaelManaged rijndaelCipher = new RijndaelManaged();
            rijndaelCipher.Mode = CipherMode.CBC;
            rijndaelCipher.Padding = PaddingMode.PKCS7;
            rijndaelCipher.KeySize = 128;
            rijndaelCipher.BlockSize = 128;
            byte[] encryptedData = Convert.FromBase64String(text);
            byte[] pwdBytes = System.Text.Encoding.UTF8.GetBytes(password);
            byte[] keyBytes = new byte[16];
            int len = pwdBytes.Length;
            if (len > keyBytes.Length) len = keyBytes.Length;
            System.Array.Copy(pwdBytes, keyBytes, len);
            rijndaelCipher.Key = keyBytes;
            byte[] ivBytes = System.Text.Encoding.UTF8.GetBytes(iv);
            rijndaelCipher.IV = ivBytes;
            ICryptoTransform transform = rijndaelCipher.CreateDecryptor();
            byte[] plainText = transform.TransformFinalBlock(encryptedData, 0, encryptedData.Length);
            return Encoding.UTF8.GetString(plainText);
        }

 /// <summary>
        /// 加密
        /// </summary>
        /// <param name="toEncrypt">明文</param>
        /// <param name="key">密码</param>
        /// <param name="iv">偏移量</param>
        /// <returns></returns>
        public static string AesEncrypt(string toEncrypt, string key, string iv)
        {

            byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);

            byte[] keyArray = UTF8Encoding.UTF8.GetBytes(key);//注意编码格式(utf8编码 UTF8Encoding)
            byte[] ivArray = UTF8Encoding.UTF8.GetBytes(iv);

            RijndaelManaged rDel = new RijndaelManaged();
            rDel.Key = keyArray;
            //如果没有偏移量，此句可以去掉
            rDel.IV = ivArray;
            rDel.Mode = CipherMode.CBC;
            //rDel.Padding = PaddingMode.Zeros;

            ICryptoTransform cTransform = rDel.CreateEncryptor();//加密
            byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
            return Convert.ToBase64String(resultArray, 0, resultArray.Length);

        }
        /// <summary>
        /// 解密 
        /// </summary>
        /// <param name="toDecrypt">解密</param>
        /// <param name="key">密码</param>
        /// <param name="iv">偏移量</param>
        /// <returns></returns>
        public static string AesDecrypt(string toDecrypt, string key, string iv)
        {
            byte[] toEncryptArray = Convert.FromBase64String(toDecrypt);
            byte[] keyArray = UTF8Encoding.UTF8.GetBytes(key);//注意编码格式(utf8编码 UTF8Encoding)
            byte[] ivArray = UTF8Encoding.UTF8.GetBytes(iv);

            RijndaelManaged rDel = new RijndaelManaged();
            rDel.Key = keyArray;
            //如果没有偏移量，此句可以去掉
            rDel.IV = ivArray;
            rDel.Mode = CipherMode.CBC;
            //rDel.Padding = PaddingMode.Zeros;

            ICryptoTransform cTransform = rDel.CreateDecryptor();//解密
            byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
            return UTF8Encoding.UTF8.GetString(resultArray);
        }

 MD5

一.使用16位、32位、64位MD5方法对用户名加密

1）16位的MD5加密



/// <summary>
/// 16位MD5加密
/// </summary>
/// <param name="password"></param>
/// <returns></returns>
public static string MD5Encrypt16(string password)
{
    var md5 = new MD5CryptoServiceProvider();
    string t2 = BitConverter.ToString(md5.ComputeHash(Encoding.Default.GetBytes(password)), 4, 8);
    t2 = t2.Replace("-", "");
    return t2;
}


2）32位的MD5加密



/// <summary>
/// 32位MD5加密
/// </summary>
/// <param name="password"></param>
/// <returns></returns>
public static string MD5Encrypt32(string password)
{
    string cl = password;
    string pwd = "";
    MD5 md5 = MD5.Create(); //实例化一个md5对像
    // 加密后是一个字节类型的数组，这里要注意编码UTF8/Unicode等的选择　
    byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(cl));
    // 通过使用循环，将字节类型的数组转换为字符串，此字符串是常规字符格式化所得
    for (int i = 0; i < s.Length; i++)
    {
        // 将得到的字符串使用十六进制类型格式。格式后的字符是小写的字母，如果使用大写（X）则格式后的字符是大写字符 
        pwd = pwd + s[i].ToString("X");
    }
    return pwd;
}


3）64位的MD5加密



public static string MD5Encrypt64(string password)
{
    string cl = password;
    //string pwd = "";
    MD5 md5 = MD5.Create(); //实例化一个md5对像
    // 加密后是一个字节类型的数组，这里要注意编码UTF8/Unicode等的选择　
    byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(cl));
    return Convert.ToBase64String(s);
}


4）使用MD5为用户密码加密



/// <summary>
/// 加密用户密码
/// </summary>
/// <param name="password">密码</param>
/// <param name="codeLength">加密位数</param>
/// <returns>加密密码</returns>
public static string md5(string password, int codeLength)
{
    if (!string.IsNullOrEmpty(password))
    {
        // 16位MD5加密（取32位加密的9~25字符）  
        if (codeLength == 16)
        {
            return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(password, "MD5").ToLower().Substring(8, 16);
        }

        // 32位加密
        if (codeLength == 32)
        {
            return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(password, "MD5").ToLower();
        }
    }
    return string.Empty;
}


      由于MD5是不可逆的，所以加密之后就无法解密，取用户名和密码时候，需要再加密一边用户输入的数据与数据库中已加密的数据进行比对。如果比对结果一致，则可以判定登陆成功！
原文链接：https://blog.csdn.net/u011555996/article/details/107051146