fwolf / fwlib

 * @param	string	$mode_directory			Same as mcrypt_module_open().

 * @return	string

*/

function McryptSmplIvProcess($i_action, $s_data, $s_key, $algorithm, $algorithm_directory = '', $mode = 'cfb', $mode_directory = '') {

	/* Open the cipher */

	$td = mcrypt_module_open($algorithm,

		$algorithm_directory,

		$mode,

		$mode_directory);

	$ks = mcrypt_enc_get_key_size($td);

	/* Create key */

	$key = substr(sha1($s_key), 0, $ks);

	// The IV must be unique and must be the same when decrypting/encrypting.

	// But encrypt/decrypt are executed on 2 machine,

	// randon IV will cause decrypt wrong result

	// Bad offical example, all put encrypt/decrypt together !

	/* Create the IV and determine the keysize length, use MCRYPT_RAND

	 * on Windows instead */

/*

	if (true == NixOs())

		$iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_DEV_RANDOM);

	else

		$iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);

*/

	// So now, I use part/duplicate sha1 value of key as IV

	$iv = sha1($key);	// Sha1 again :-)

	$l_sha1 = strlen($iv);

	$l_iv = mcrypt_enc_get_iv_size($td);

	if ($l_sha1 < $l_iv) {

		// Duplicate sha1 value to generate IV

		$iv = str_repeat($iv, round($l_iv / $l_sha1) + 1);

	}

	$iv = substr($iv, 0, $l_iv);

	/* Intialize encryption */

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

	if (0 == $i_action) {

		/* Encrypt data */

		$encrypted = mcrypt_generic($td, $s_data);

	}

	else {

		/* Decrypt encrypted string */

		$encrypted = mdecrypt_generic($td, $s_data);

	}

	/* Terminate decryption handle and close module */

	mcrypt_generic_deinit($td);

	mcrypt_module_close($td);

	return($encrypted);

} // end of func McryptSmplIvProcess

?>

     * @param   string  $modeDirectory          Same as mcrypt_module_open()

     * @return  string

    */

    public function process(

        $action,

        $source,

        $key,

        $algorithm,

        $algorithmDirectory = '',

        $mode = 'cfb',

        $modeDirectory = ''

    ) {

        self::checkExtension(true);

        // Open the cipher

        $td = mcrypt_module_open(

            $algorithm,

            $algorithmDirectory,

            $mode,

            $modeDirectory

        );

        $ks = mcrypt_enc_get_key_size($td);

        // Create key

        $key = substr(sha1($key), 0, $ks);

        /**

         *

         * The IV must be unique and must be the same when decrypting/encrypting.

         *

         * But encrypt/decrypt are executed on 2 machine,

         * random IV will cause decrypt wrong result

         *

         * So now, I use part/duplicate sha1 value of key as IV

         *

         * Bad official example, all put encrypt/decrypt together !

         */

        $iv = sha1($key);   // Sha1 again :-)

        $lenSha1 = strlen($iv);

        $lenIv = mcrypt_enc_get_iv_size($td);

        // @codeCoverageIgnoreStart

        if ($lenSha1 < $lenIv) {

            // Duplicate sha1 value to generate IV

            $iv = str_repeat($iv, round($lenIv / $lenSha1) + 1);

        }

        // @codeCoverageIgnoreEnd

        $iv = substr($iv, 0, $lenIv);

        // Initialize encryption

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

        if (0 == $action) {

            // Encrypt data

            $encrypted = mcrypt_generic($td, $source);

        } else {

            // Decrypt encrypted string

            $encrypted = mdecrypt_generic($td, $source);

        }

        // Terminate decryption handle and close module

        mcrypt_generic_deinit($td);

        mcrypt_module_close($td);

        return($encrypted);

    }

}