Encryption using Triple DES

[vidyar_rajan]

hi guys,

currently i am working on a project where we are encrypting a string using triple DES. this encrypted is used for decryting in VC++(this is done by the client) can anyone tell me different ways of performing triple DES encryption.

 

Please reply ASAP

thank you in advance. 

 

Thanks,

Vidya

[btherl]

This can get you started

 

http://sg.php.net/manual/en/ref.mcrypt.php

 

"This is an interface to the mcrypt library, which supports a wide variety of block algorithms such as DES, TripleDES, Blowfish (default), 3-WAY, SAFER-SK64, SAFER-SK128, TWOFISH, TEA, RC2 and GOST in CBC, OFB, CFB and ECB cipher modes."

 

Is your question "How do I implement 3DES in php", or are you asking more generally about how 3DES can be used?

[achuthanz]

I have a similar problem where my 3DES encrypted string using PHP needs to be decrypted by a .NET class using CryptoStream.

 

But, the output of encryption between the php code and .NET class are not matching.

 

PHP:

 

    $string = 'To encrypt';

    echo '<b>Original String:</b>'.$string.'<br>';

    $td = mcrypt_module_open (MCRYPT_TRIPLEDES, '', MCRYPT_MODE_CBC, '');

 

    $ks = mcrypt_enc_get_key_size ($td);

    $key = substr ('abcdefghijklmnop', 0, $ks);

    $key = utf8_encode($key);

 

    $iv = 'zyxwvuts';

    $iv = utf8_encode($iv);

 

    mcrypt_generic_init ($td, $key, $iv);

 

    $encryptedString = mcrypt_generic ($td, utf8_encode($string));

    mcrypt_generic_deinit ($td);

    echo '<b>Encrypted:</b>'.base64_encode($encryptedString).'<br>';

 

    mcrypt_generic_init ($td, $key, $iv);

    $decryptedString = mdecrypt_generic ($td, $encryptedString);

    echo '<b>Decrypted:</b>'.trim($decryptedString).'<br>';

 

    mcrypt_generic_deinit ($td);

    mcrypt_module_close ($td);

 

 

.NET

http://msdn2.microsoft.com/en-us/library/aa302405.aspx

 

Can someone tell what is wrong with the PHP code??

[MadTechie]

.Net using padding, php doesn't try this

 

check the .Net and set the padding to Zeros

 

            TripleDES tdes = TripleDES.Create();
            tdes.Padding = PaddingMode.Zeros;

 

 

then pad the php version

    $buffer = $_POST['data']; 
    // get the amount of bytes to pad
    $extra = 8 - (strlen($buffer) % ;
    // add the zero padding
    if($extra > 0) {
        for($i = 0; $i < $extra; $i++) {
            $buffer .= "\0";
        }
    }

[achuthanz]

Nope. That isn't working. 

The results are still different..