Solution for differences between MD5 encryption in. NET and MD5 encryption value in ASP

Problem: an ASP to ASP is being created. net mall revision, the original registered users need to retain, the original user password is ASP MD5, 32-bit encryption, remember ASP MD5 and ASP.. Net's MD5 encryption results are not equal, so I tried:
The original MD5 encryption method is as follows:
/// <Summary>
/// MD5 Encryption Algorithm
/// </Summary>
/// <Param name = "md5str"> string to be encrypted </param>
/// <Returns> MD5 encryption result </returns>
Public static string getmd5 (string md5str)
{
Byte [] data;
String ret = "";
Data = system. Text. encoding. utf8.getbytes (md5str );
Md5cryptoserviceprovider md5obj = new md5cryptoserviceprovider ();
Byte [] md5byte = md5obj. computehash (data );
For (INT I = 0; I <md5byte. length; I ++)
{
RET + = md5byte [I]. tostring ("X"). padleft (2, '0 ');
}
Return ret;
}

Later, I found a simpler implementation method.
/// <Summary>
/// MD5 Encryption Algorithm
/// </Summary>
/// <Param name = "md5str"> string to be encrypted </param>
/// <Returns> MD5 encryption result </returns>
Public static string getmd5 (string md5str)
{
Return System. Web. Security. formsauthentication. hashpasswordforstoringinconfigfile (md5str, "MD5 ");
}

Use the second method to output the MD5 encryption result of "admin:
21232F297A57A5A743894A0E4A801FC3
Comparison with ASP MD5-encrypted 16-bit and 32-bit encryption:
16-bit encryption (7a57a5a743894a0e)
32-bit encryption (21232f297a57a5a743894a0e4a801fc3)

It is found that the results are the same as those of 32-bit encryption, but the uppercase and lowercase letters are different. The 16-bit encryption results only include 16 in the middle of the 32-bit encryption results, so:
/// <Summary>
/// ASP MD5 Encryption Algorithm
/// </Summary>
/// <Param name = "md5str"> string to be encrypted </param>
/// <Param name = "type"> 16 or 32-bit encryption </param>
/// <Returns> Asp md5 encryption result </returns>
Public static string GetAspMd5 (string md5str, int type)
{
If (type = 16)
{
Return System. Web. Security. formsauthentication. hashpasswordforstoringinconfigfile (md5str, "MD5"). substring (8, 16). tolower ();
}
Else if (type = 32)
{
Return System. Web. Security. formsauthentication. hashpasswordforstoringinconfigfile (md5str, "MD5"). tolower ();
}
Return "";
}
The above method implements ASP MD5 encryption results in. NET.

----------------------- 2007.08.07 plus ----------------------------------

It seems that this problem has been solved for a long time. I found the following methods in my previous projects:

Public static string GetMD5 (string s)
{

/// <Summary>
/// ASP-compatible MD5 Encryption Algorithm
/// </Summary>

MD5 md5 = new MD5CryptoServiceProvider ();
Byte [] t = md5.ComputeHash (Encoding. GetEncoding ("gb2312"). GetBytes (s ));
Stringbuilder sb = new stringbuilder (32 );
For (INT I = 0; I <t. length; I ++)
{
SB. append (T [I]. tostring ("X"). padleft (2, '0 '));
}
Return sb. tostring ();
}