[送分]请求写一个下面DES加密函数的对称解密函数!

Question

//=================================================================================== 
   public static string Decrypt(string pToDecrypt, string sKey)
    {
        DESCryptoServiceProvider provider1 = new DESCryptoServiceProvider();        byte[] buffer1 = new byte[pToDecrypt.Length / 2];        for (int num1 = 0; num1 < (pToDecrypt.Length / 2); num1++)
        {
            int num2 = Convert.ToInt32(pToDecrypt.Substring(num1 * 2, 2), 0x10);
            buffer1[num1] = (byte)num2;
        }
        provider1.Key = Encoding.ASCII.GetBytes(sKey);
        provider1.IV = Encoding.ASCII.GetBytes(sKey);
        MemoryStream stream1 = new MemoryStream();
        CryptoStream stream2 = new CryptoStream(stream1, provider1.CreateDecryptor(), CryptoStreamMode.Write);
        stream2.Write(buffer1, 0, buffer1.Length);
        stream2.FlushFinalBlock();
        StringBuilder builder1 = new StringBuilder();
        return Encoding.Default.GetString(stream1.ToArray());
    }
//=================================================================================如题请求写一个逆向对称解密函数,谢谢!

Answer 1

应该不难写,帮帮忙,偶刚学ASP.Net 有些不懂呀!

Answer 2

你是用Encoding.ASCII.GetBytes作密匙得，非常麻烦。好像是要16位
我用System.Text.Encoding.Unicode.GetBytespublic static string Decrypt(string datastr, string keystr) 
{
 
System.Security.Cryptography.DESCryptoServiceProvider desc = new System.Security.Cryptography.DESCryptoServiceProvider();
byte[] key = System.Text.Encoding.Unicode.GetBytes(keystr);
byte[] data = Convert.FromBase64String(datastr);
System.IO.MemoryStream ms = new System.IO.MemoryStream();//存储解密后的数据
CryptoStream cs = new CryptoStream(ms, desc.CreateDecryptor(key, key), CryptoStreamMode.Write);
cs.Write(data, 0, data.Length);//解密数据
cs.FlushFinalBlock();
return System.Text.Encoding.Unicode.GetString(ms.ToArray());
 
}

Answer 3

这个函数得配套加密函数，你根据差别是可以修改出合适自己得。
public static  string Encrypt(string datastr, string keystr) 
{
 
DESCryptoServiceProvider desc = new DESCryptoServiceProvider();//des进行加密
byte[] key = System.Text.Encoding.Unicode.GetBytes(keystr);
byte[] data = System.Text.Encoding.Unicode.GetBytes(datastr);
MemoryStream ms = new MemoryStream();//存储加密后的数据
CryptoStream cs = new CryptoStream(ms, desc.CreateEncryptor(key, key), CryptoStreamMode.Write);
cs.Write(data, 0, data.Length);//进行加密
cs.FlushFinalBlock();
return Convert.ToBase64String(ms.ToArray());//取加密后的数据
 
}

Answer 4

我写过如下的.确不行.加密后要是16进制的字符串.因为一些原因,我不能用你的例子那样的准标过程.麻烦大哥再帮我看下吧.//==============================================================
 
public static string Encrypt(string pToEncrypt, string sKey)
    {
        DESCryptoServiceProvider provider2 = new DESCryptoServiceProvider();        byte[] buffer3 = new byte[pToEncrypt.Length];        provider2.Key = Encoding.ASCII.GetBytes(sKey);
        provider2.IV = Encoding.ASCII.GetBytes(sKey);
        MemoryStream stream5 = new MemoryStream();
        CryptoStream stream6 = new CryptoStream(stream5, provider2.CreateEncryptor(), CryptoStreamMode.Write);
        stream6.Write(buffer3, 0, buffer3.Length);
        stream6.FlushFinalBlock();
       // StringBuilder builder1 = new StringBuilder();
        //return Encoding.Default.GetString(stream1.ToArray());
       byte[] buffer4 = new byte[stream5.ToArray().Length];
       buffer4 = stream5.ToArray();
       string text1= "";
       for (int num1 = 0; num1 < buffer4.Length;num1++)
       {
           int num2 = (Int32)buffer4[num1];
           text1 = text1 + Convert.ToString(num2, 0x10);
           //text1 = text1 + buffer2[num1].ToString() + " " ;
       }
       return text1.ToUpper();
    }

Answer 5

public static string Encrypt(string pToEncrypt, string sKey)
    {
        DESCryptoServiceProvider provider2 = new DESCryptoServiceProvider();        byte[] buffer3 = new byte[pToEncrypt.Length];        provider2.Key = Encoding.ASCII.GetBytes(sKey);
        provider2.IV = Encoding.ASCII.GetBytes(sKey);
        MemoryStream stream5 = new MemoryStream();
        CryptoStream stream6 = new CryptoStream(stream5, provider2.CreateEncryptor(), CryptoStreamMode.Write);
        stream6.Write(buffer3, 0, buffer3.Length);
        stream6.FlushFinalBlock();
       // StringBuilder builder1 = new StringBuilder();
        //return Encoding.Default.GetString(stream1.ToArray());
       byte[] buffer4 = new byte[stream5.ToArray().Length];
       buffer4 = stream5.ToArray();
       string text1= "";
       
       for (int num1 = 0; num1 < buffer4.Length;num1++)
       {
            text1= text1+ buffer4[i].ToString("X").PadLeft(2,'0');
        }
       return text1;

Answer 6

text1= text1+ buffer4[num1].ToString("X").PadLeft(2,'0');