DES，AeS加解密，MD5，SHA加密

1、DES一共就有4个参数参与运作：明文、密文、密钥、向量。其中这4者的关系可以理解为：

　　密文=明文+密钥+向量；
　　明文=密文-密钥-向量；
　　为什么要向量这个参数呢？因为如果有一篇文章，有几个词重复，那么这个词加上密钥形成的密文，仍然会重复，这给破解者有机可乘，破解者可以根据重复的内容，猜出是什么词，然而一旦猜对这个词，那么，他就能算出密钥，整篇文章就被破解了！加上向量这个参数以后，每块文字段都会依次加上一段值，这样，即使相同的文字，加密出来的密文，也是不一样的，算法的安全性大大提高！

2、AES是美国联邦政府采用的商业及政府数据加密标准，预计将在未来几十年里代替DES在各个领域中得到广泛应用。AES提供128位密钥，因此，128位AES的加密强度是56位DES加密强度的1021倍还多。假设可以制造一部可以在1秒内破解DES密码的机器，那么使用这台机器破解一个128位AES密码需要大约149亿万年的时间。

3、MD5和SHA1散列通常被用于密码中，很多人称其为散列算法。散列是不可逆的，也就是没有了"解密"这个说法。

des加解密参考：http://www.faceye.net/search/110023.html

加解密只是参考：http://blog.csdn.net/z1x1c1v1/article/details/8755032

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Security.Cryptography;
using System.IO;

namespace WinForms_Crypt
{
    public partial class Form3 : Form
    {
        /// <summary>
        /// 加密解密方式
        /// </summary>
        private enum CryptType
        {
            MD5,DES,AES
        }

        /// <summary>
        /// 当前使用的加解密方式
        /// </summary>
        CryptType type = CryptType.MD5;

        public Form3()
        {
            InitializeComponent();

            if (type == CryptType.MD5)
            {
                button_Decrypt.Enabled = false;
                button_Encrypt.Enabled = true;
            }
            else if (type == CryptType.DES)
            {
                button_Decrypt.Enabled = true;
                button_Encrypt.Enabled = true;
            }
            else if (type == CryptType.AES)
            {
                button_Decrypt.Enabled = true;
                button_Encrypt.Enabled = true;
            }
        }

        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button_Encrypt_Click(object sender, EventArgs e)
        {
            //明文 
            string MingWen = textBox_DecryptText.Text.Trim();
            //加密得到的密文
            string MiWen = "";
            if (MingWen != "")
            {
                if (type == CryptType.MD5)
                {
                    MiWen = "MD5Base64："+MD5_Crypt.GetHashStr(MingWen);
                    MiWen += "
 MD5：" + MD5_Crypt2.MD5(MiWen);
                    MiWen += "
 SHA128：" + MD5_Crypt2.SHA128(MiWen);
                    MiWen += "
 SHA256：" + MD5_Crypt2.SHA256(MiWen);
                    MiWen += "
 SHA384：" + MD5_Crypt2.SHA384(MiWen);
                    MiWen += "
 SHA512：" + MD5_Crypt2.SHA512(MiWen);
                }
                else if (type == CryptType.DES)
                {
                    MiWen = DES_Crypt.Encrypt(MingWen);
                }
                else if (type == CryptType.AES)
                {
                    MiWen = AeS_Crypt.Encrypt(MingWen);
                } 
            }
            textBox_EncyptText.Text = MiWen;
        }

        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button_Decrypt_Click(object sender, EventArgs e)
        {
            //密文
            string MiWen = textBox_EncyptText.Text.Trim();
            //解密得到的明文
            string MingWen = "";
            //无法解析哈希值
            if (MiWen != "")
            {
                if (type == CryptType.MD5)
                {
                    MessageBox.Show("MD5无法解密");
                }
                else if (type == CryptType.DES)
                {
                    MingWen = DES_Crypt.Decrypt(MiWen);
                }
                else if (type == CryptType.AES)
                {
                    MingWen = AeS_Crypt.Decrypt(MiWen);

                }
            }
            textBox_DecryptText.Text = MingWen;
        }
    }

    /// <summary>
    /// MD5加密
    /// </summary>
    public class MD5_Crypt
    {
        /// <summary>
        /// MD5加密
        /// </summary>
        /// <param name="inputByt">原文</param>
        /// <returns>加密后的字节数组</returns>
        public static byte[] GetHash(byte[] inputByt)
        {
            HashAlgorithm algorithm = HashAlgorithm.Create("MD5");
            return algorithm.ComputeHash(inputByt);
        }
        /// <summary>
        /// MD5加密
        /// </summary>
        /// <param name="inputStr">原文</param>
        /// <returns>加密后的字节数组</returns>
        public static byte[] GetHash(string inputStr)
        {
            byte[] inputByt = new UnicodeEncoding().GetBytes(inputStr);

            return GetHash(inputByt);
        }
        /// <summary>
        /// MD5加密
        /// </summary>
        /// <param name="inputStr">原文</param>
        /// <returns>BASE64编码字符串</returns>
        public static string GetHashStr(string inputStr)
        {
            return Convert.ToBase64String(GetHash(inputStr));
        }

        /// <summary>
        /// MD5加密
        /// </summary>
        /// <param name="inputStr">原文</param>
        /// <returns>32位编码</returns>
        public static string GetHashString32(string inputStr)
        {
            string hash = BitConverter.ToString(GetHash(inputStr));
            return hash.Replace("-", "");
        }

        /// <summary>
        /// MD5加密
        /// </summary>
        /// <param name="inputStr">原文</param>
        /// <returns>32位编码</returns>
        public static string GetHashString(byte[] inputStr)
        {
            string hash = BitConverter.ToString(GetHash(inputStr));
            return hash.Replace("-", "");
        }
    }

    /// <summary>
    /// DES加解密
    /// </summary>
    public class DES_Crypt
    { 
        /// <summary>
        /// 获取密钥
        /// </summary>
        private static string Key
        {
            get { return @"P@+#wG%A"; }
        }

        /// <summary>
        /// 获取向量
        /// </summary>
        private static string IV
        {
            get { return @"L*n67}GMk@k%:~Y"; }
        }

        /// <summary>
        /// DES加密
        /// </summary>
        /// <param name="plainStr">明文字符串</param>
        /// <returns>密文</returns>
        public static string Encrypt(string plainStr)
        {
            byte[] bKey = Encoding.UTF8.GetBytes(Key);
            byte[] bIV = Encoding.UTF8.GetBytes(IV);
            byte[] byteArray = Encoding.UTF8.GetBytes(plainStr);

            string encrypt = null;
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            try
            {
                using (MemoryStream mStream = new MemoryStream())
                {
                    using (CryptoStream cStream = new CryptoStream(mStream, des.CreateEncryptor(bKey, bIV), CryptoStreamMode.Write))
                    {
                        cStream.Write(byteArray, 0, byteArray.Length);
                        cStream.FlushFinalBlock();
                        encrypt = Convert.ToBase64String(mStream.ToArray());
                    }
                }
            }
            catch { }
            des.Clear();
            return encrypt;
        }

        /// <summary>
        /// DES解密
        /// </summary>
        /// <param name="encryptStr">密文字符串</param>
        /// <returns>明文</returns>
        public static string Decrypt(string encryptStr)
        {
            byte[] bKey = Encoding.UTF8.GetBytes(Key);
            byte[] bIV = Encoding.UTF8.GetBytes(IV);
            byte[] byteArray = Convert.FromBase64String(encryptStr);

            string decrypt = null;
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            try
            {
                using (MemoryStream mStream = new MemoryStream())
                {
                    using (CryptoStream cStream = new CryptoStream(mStream, des.CreateDecryptor(bKey, bIV), CryptoStreamMode.Write))
                    {
                        cStream.Write(byteArray, 0, byteArray.Length);
                        cStream.FlushFinalBlock();
                        decrypt = Encoding.UTF8.GetString(mStream.ToArray());
                    }
                }
            }
            catch { }
            des.Clear();
            return decrypt;
        }
    }

    /// <summary>
    /// AES加解密
    /// </summary>
    public class AeS_Crypt
    { 
        /// <summary>
        /// 获取密钥
        /// </summary>
        private static string Key
        {
            get { return @"qO[NB]6,YF}gefcaj{+oESb9d8>Z'e9M"; }
        }

        /// <summary>
        /// 获取向量
        /// </summary>
        private static string IV
        {
            get { return @"L+~f4.Ir)b$=pkf"; }
        }

        /// <summary>
        /// AES加密
        /// </summary>
        /// <param name="plainStr">明文字符串</param>
        /// <returns>密文</returns>
        public static string Encrypt(string plainStr)
        {
            byte[] bKey = Encoding.UTF8.GetBytes(Key);
            byte[] bIV = Encoding.UTF8.GetBytes(IV);
            byte[] byteArray = Encoding.UTF8.GetBytes(plainStr);

            string encrypt = null;
            Rijndael aes = Rijndael.Create();
            try
            {
                using (MemoryStream mStream = new MemoryStream())
                {
                    using (CryptoStream cStream = new CryptoStream(mStream, aes.CreateEncryptor(bKey, bIV), CryptoStreamMode.Write))
                    {
                        cStream.Write(byteArray, 0, byteArray.Length);
                        cStream.FlushFinalBlock();
                        encrypt = Convert.ToBase64String(mStream.ToArray());
                    }
                }
            }
            catch { }
            aes.Clear();
            return encrypt;
        }

        /// <summary>
        /// AES解密
        /// </summary>
        /// <param name="encryptStr">密文字符串</param>
        /// <returns>明文</returns>
        public static string Decrypt(string encryptStr)
        {
            byte[] bKey = Encoding.UTF8.GetBytes(Key);
            byte[] bIV = Encoding.UTF8.GetBytes(IV);
            byte[] byteArray = Convert.FromBase64String(encryptStr);

            string decrypt = null;
            Rijndael aes = Rijndael.Create();
            try
            {
                using (MemoryStream mStream = new MemoryStream())
                {
                    using (CryptoStream cStream = new CryptoStream(mStream, aes.CreateDecryptor(bKey, bIV), CryptoStreamMode.Write))
                    {
                        cStream.Write(byteArray, 0, byteArray.Length);
                        cStream.FlushFinalBlock();
                        decrypt = Encoding.UTF8.GetString(mStream.ToArray());
                    }
                }
            }
            catch { }
            aes.Clear();
            return decrypt;
        }
    }

    public class MD5_Crypt2
    {
        //16字节,128位
        public static string MD5(string str)
        {
            byte[] buffer = Encoding.UTF8.GetBytes(str);
            MD5CryptoServiceProvider MD5 = new MD5CryptoServiceProvider();
            byte[] byteArr = MD5.ComputeHash(buffer);
            return BitConverter.ToString(byteArr);
        }

        //20字节,160位
        public static string SHA128(string str)
        {
            byte[] buffer = Encoding.UTF8.GetBytes(str);
            SHA1CryptoServiceProvider SHA1 = new SHA1CryptoServiceProvider();
            byte[] byteArr = SHA1.ComputeHash(buffer);
            return BitConverter.ToString(byteArr);
        }

        //32字节,256位
        public static string SHA256(string str)
        {
            byte[] buffer = Encoding.UTF8.GetBytes(str);
            SHA256CryptoServiceProvider SHA256 = new SHA256CryptoServiceProvider();
            byte[] byteArr = SHA256.ComputeHash(buffer);
            return BitConverter.ToString(byteArr);
        }

        //48字节,384位
        public static string SHA384(string str)
        {
            byte[] buffer = Encoding.UTF8.GetBytes(str);
            SHA384CryptoServiceProvider SHA384 = new SHA384CryptoServiceProvider();
            byte[] byteArr = SHA384.ComputeHash(buffer);
            return BitConverter.ToString(byteArr);
        }

        //64字节,512位
        public static string SHA512(string str)
        {
            byte[] buffer = Encoding.UTF8.GetBytes(str);
            SHA512CryptoServiceProvider SHA512 = new SHA512CryptoServiceProvider();
            byte[] byteArr = SHA512.ComputeHash(buffer);
            return BitConverter.ToString(byteArr);
        }
    }
}