Reply to Re: Cannot generate random image for form security - help

Your name:

Reply:


Posted by comp.lang.php on 04/04/06 19:48

comp.lang.php wrote:
> See below, thanx
>
> Oli Filth wrote:
> > comp.lang.php said the following on 03/04/2006 23:00:
> > <...SNIP CODE...>
> > >
> > > This class method is supposed to generate one of those random images
> > > you see on forms, you know, with the letters and numbers all mixed up
> > > for people to type it in for security and repost protection purposes.
> > >
> > > This method, however, fails. No errors, no warnings, no notices, not
> > > even a broken image, it just DIES on the spot, completely, stops dead
> > > on the line:
> > >
> > > [PHP]
> > > if (!$image && strcmp($type, 'gif') != 0) $image =
> > > imagecreatetruecolor(150, 30); else $im = imagecreate(100, 50) or
> > > die("Cannot Initialize new GD image stream");
> > > [/PHP]
> > >
> >
> > I'm not going to attempt to debug your code, but firstly, do you
> > definitely have error reporting level set to E_ALL? Secondly, you're
> > using eval() on the line before this, so there's a good chance that this
> > could cock things up. Incidentally, why are you using eval() at all?
> >
>
> I debug by setting error_reporting() to E_ALL, however, that does not
> show anything, not even notices that could be spawned.
>
> Secondly, the reason I'm using eval() is very simple: I will be
> generating a random image that could be a PNG, a GIF, a JPEG, a TIFF, a
> BMP, etc., depending on the immediate need, thus, one command like
> imagepng() or imagejpeg() is insufficient.

** UPDATE **
Turns out that the Linux package "php-gd" was never installed. An
update with that and httpd restart fixed the lack-of-GD problem.

However, there is another problem: I am trying to create a brand new
image file. How do you do that using GD? Each time I try the image
file does not exist.

/**
* Generate the random security image
*
* @access public
* @param $willUseFilePath (default false) boolean to determine if you
will be using a file path
* @param mixed $filePath (optional) file path to store image resource
object contents
* @see actual_path
*/
function &generate($willUseFilePath = false, $filePath = '') { //
STATIC VOID METHOD

if ($this->hasGD() && $this->dbAP->isSuccessful) {

$type = $this->getImageType();
$length = $this->getLength();
if ($willUseFilePath && $filePath) $this->setFilePath($filePath);

$text = $this->generateText();
$fileName = $this->getFileName();
if (!$fileName) {
$fileName = $this->generateFileName();
$this->setFileName($fileName);
}

// create an temporary image from an image file
if (is_file(actual_path("$filePath/$fileName"))) $msg = eval('$image
= imagecreatefrom' . $type . '(actual_path("$filePath/$fileName"));');
if (!$image && strcmp($type, 'gif') != 0) $image =
imagecreatetruecolor(150, 30); else $image = imagecreate(100, 50);
if (!$image) {
$this->dbAP->isSuccessful = false;
$this->dbAP->setErrorArray(array('action' => 'Unable to generate
random image for form security'));
}

// get a color from the image (in this case, yellow)
$orange = imagecolorallocate($image, 220, 210, 60);

// Now we need to get widh and height of the image, so that we can
center the key on the image, so that it does not go outside of the
borders or look strange
$width = (imagesx($image) - 7.5 * strlen($text)) / 2;
$height = (imagesy($image) - 7.5) / 2;

// here we write the key (the string) on the image
imagestring($image, 3, $width, $height, $text, $orange);

// now create the final image [ADDITIONAL: ADD TO FILE IF FILE
NAME INDICATED]
if ($willUseFilePath && $filePath) {
$msg = eval('image' . $type . '($image, "$filePath/$fileName");');
} else {
$msg = eval('image' . $type . '($image);');
}

// to free up results, we need to destroy the temporary image.
imagedestroy($image);

if (is_file(actual_path("$filePath/$fileName")) || $msg) {
$this->setSession($fileName, $text);
} else {
$this->dbAP->isSuccessful = false;
$this->dbAP->setErrorArray(array('action' => "Unable to generate
random image \"$filePath/$fileName\" for form security: " .
nl2br($msg)));
}

}
}

Phil

>
> Phil
>
>
> > --
> > Oli

[Back to original message]


Удаленная работа для программистов  •  Как заработать на Google AdSense  •  England, UK  •  статьи на английском  •  PHP MySQL CMS Apache Oscommerce  •  Online Business Knowledge Base  •  DVD MP3 AVI MP4 players codecs conversion help
Home  •  Search  •  Site Map  •  Set as Homepage  •  Add to Favourites

Copyright © 2005-2006 Powered by Custom PHP Programming

Сайт изготовлен в Студии Валентина Петручека
изготовление и поддержка веб-сайтов, разработка программного обеспечения, поисковая оптимизация