Re: TripleDES Encryption issue

From: Cowboy \(Gregory A Beamer\) (NoSpamMgbworld_at_comcast.netNoSpamM)
Date: 09/06/03

  • Next message: Sam Page: "Thread Unable to Impersonate (Workaround)" 
    Date: Sat, 6 Sep 2003 12:08:40 -0500

    Change the stream type. The encryption samples use a file stream, but any
    type of stream can be used to encrypt/decrypt. I have seen plenty of samples
    with strings, as well as files, but you are correct that many of the samples
    are file based.

    Hope this helps. 

    -- 
Gregory A. Beamer
MPV; MCP: +I, SE, SD, DBA
**********************************************************************
Think outside the box!
**********************************************************************
"jdn" <kingcrim@earthlink.net> wrote in message
news:uAMyKjEdDHA.904@TK2MSFTNGP11.phx.gbl...
> I'm new to using this part of the framework, so I'm hoping I've done
> something obviously stupid, which someone will be able to point out in
> an obvious manner.
>
> Most of the samples I've seen involved encrypting and decrypting to and
> from a file, but that's not what I want.  I want to be able to insert a
> string into an encryption function which outputs that encrypted string,
> which could then be sent into a decryption function and spit out the
> original string.
>
> As you might expect, ultimately, I want to be able to put this string
> into a database table.
>
> Anyways, I set up a simple test page where I enter a string in a
> textbox, and then run it through an encrypt, then decrypt, function, and
> print out to some labels to make sure it is doing it correctly.
>
> The encrypt part seems to work (at least the function doesn't fail), but
> the decrypt function fails, with an error saying that the length of the
> encrypted string is invalid.  Here are the functions:
>
> **************************************************************
>
> public static string Encrypt(string StringToEncrypt){
> string EncryptedString;
> UTF8Encoding utf8encoder = new UTF8Encoding();
> byte[] inputInBytes = utf8encoder.GetBytes(StringToEncrypt);
> TripleDESCryptoServiceProvider tdesProvider = new
> TripleDESCryptoServiceProvider();
> ICryptoTransform cryptoTransform =
> tdesProvider.CreateEncryptor(tdeskey, tdesIV);
> MemoryStream encryptedStream = new MemoryStream();
> CryptoStream cryptStream = new CryptoStream(encryptedStream,
> cryptoTransform, CryptoStreamMode.Write);
>
> cryptStream.Write(inputInBytes, 0, inputInBytes.Length);
> cryptStream.FlushFinalBlock();
> encryptedStream.Position = 0;
>
> byte[] result = new byte[encryptedStream.Length - 1];
> encryptedStream.Read(result, 0, (int)(encryptedStream.Length - 1));
> cryptStream.Close();
>
> UTF8Encoding myutf = new UTF8Encoding();
> EncryptedString = myutf.GetString(result);
> return EncryptedString;
> }//end Encrypt
>
> public static string Decrypt(string StringToDecrypt){
> string DecryptedString;
>
>
> UTF8Encoding utf8encoder = new UTF8Encoding();
> byte[] inputInBytes = utf8encoder.GetBytes(StringToDecrypt);
> TripleDESCryptoServiceProvider tdesProvider = new
> TripleDESCryptoServiceProvider();
> ICryptoTransform cryptoTransform =
> tdesProvider.CreateDecryptor(tdeskey, tdesIV);
> MemoryStream decryptedStream = new MemoryStream();
> CryptoStream cryptStream = new CryptoStream(decryptedStream,
> cryptoTransform, CryptoStreamMode.Write);
>
> cryptStream.Write(inputInBytes, 0, (inputInBytes.Length));
> cryptStream.FlushFinalBlock();
> decryptedStream.Position = 0;
>
> byte[] result = new byte[decryptedStream.Length - 1];
> decryptedStream.Read(result, 0, (int)(decryptedStream.Length - 1));
> cryptStream.Close();
>
> DecryptedString = result.ToString();
>
> return DecryptedString;
> }//end Decrypt
>
> ************************************************************************
>
> cryptStream.FlushFinalBlock() in the decrypt function is what fails.
>
> Any ideas would be greatly welcomed.
>
> jdn
> kingcrim@earthlink.net
>
  • Next message: Sam Page: "Thread Unable to Impersonate (Workaround)"

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