"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
>

Cowboy (Gregory A Beamer) wrote:

> 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.
>

Cowboy (Gregory A Beamer) wrote:

> 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.
>

"jdn" <kingcrim@earthlink.net> wrote in message =
news:uTuNAWYdDHA.2932@tk2msftngp13.phx.gbl...
Cowboy (Gregory A Beamer) wrote:

> 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.
>=20
> Hope this helps.
>=20

Drebin wrote:

> There are several kinds of streams, IO streams, memory streams, XML streams.. etc.. so if you are dealing with a filestream - then you will only really be able to read/write from a file.. if you want to read/write to a variable, you likely need a MemoryStream or some equivalent..
>
>
> "jdn" <kingcrim@earthlink.net> wrote in message news:uTuNAWYdDHA.2932@tk2msftngp13.phx.gbl...
> Cowboy (Gregory A Beamer) wrote:
>
>
>>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.
>>
>
>
>
> Why would changing the stream type fix the issue? It seems to have to
> do with how the decrypt function is written or maybe with how the
> encrypt function writes the string.
>
> jdn
>