Encryption and decryption problems (keys)

When configuring the website database, it is often difficult to encrypt the appsonstring of the ettings in Web. config. The common encryption method is DES encryption/decryption.

An error is always reported during website configuration today. The error is as follows:

During this period, I found a lot of information on the Internet, but I didn't want it. Later I found that the keys used for encryption and decryption were different. I was depressed for a long time.

# Region ========= encryption ========

/// <Summary>
/// Encryption
/// </Summary>
/// <Param name = "text"> </param>
/// <Returns> </returns>
Public static string encrypt (string text)
{
Return encrypt (text, Key );
}
/// <Summary>
/// Encrypt data
/// </Summary>
/// <Param name = "text"> </param>
/// <Param name = "skey"> </param>
/// <Returns> </returns>
Public static string encrypt (string text, string skey)
{
Descryptoserviceprovider des = new descryptoserviceprovider ();
Byte [] inputbytearray;
Inputbytearray = encoding. Default. getbytes (text );
Des. Key = asciiencoding. ASCII. getbytes (system. Web. Security. formsauthentication. hashpasswordforstoringinconfigfile (skey, "MD5"). substring (0, 8 ));
Des. IV = asciiencoding. ASCII. getbytes (system. Web. Security. formsauthentication. hashpasswordforstoringinconfigfile (skey, "MD5"). substring (0, 8 ));
System. Io. memorystream MS = new system. Io. memorystream ();
Cryptostream cs = new cryptostream (MS, Des. createencryptor (), cryptostreammode. Write );
CS. Write (inputbytearray, 0, inputbytearray. Length );
CS. flushfinalblock ();
Stringbuilder ret = new stringbuilder ();
Foreach (byte B in ms. toarray ())
{
Ret. appendformat ("{0: X2}", B );
}
Return ret. tostring ();
}

# Endregion

# Region ========= decryption ========

/// <Summary>
/// Decrypt
/// </Summary>
/// <Param name = "text"> </param>
/// <Returns> </returns>
Public static string decrypt (string text)
{
Return decrypt (text, Key );
}
/// <Summary>
/// Decrypt data
/// </Summary>
/// <Param name = "text"> </param>
/// <Param name = "skey"> </param>
/// <Returns> </returns>
Public static string decrypt (string text, string skey)
{
Descryptoserviceprovider des = new descryptoserviceprovider ();
Int Len;
Len = text. Length/2;
Byte [] inputbytearray = new byte [Len];
Int X, I;
For (x = 0; x <Len; X ++)
{
I = convert. toint32 (text. substring (x * 2, 2), 16 );
Inputbytearray [x] = (byte) I;
}
Des. Key = asciiencoding. ASCII. getbytes (system. Web. Security. formsauthentication. hashpasswordforstoringinconfigfile (skey, "MD5"). substring (0, 8 ));
Des. IV = asciiencoding. ASCII. getbytes (system. Web. Security. formsauthentication. hashpasswordforstoringinconfigfile (skey, "MD5"). substring (0, 8 ));
System. Io. memorystream MS = new system. Io. memorystream ();
Cryptostream cs = new cryptostream (MS, Des. createdecryptor (), cryptostreammode. Write );
CS. Write (inputbytearray, 0, inputbytearray. Length );
CS. flushfinalblock ();
Return encoding. Default. getstring (Ms. toarray ());
}

# Endregion