SecureImage Options
SecureImage combines a variable length, random text string over multiple .png backgrounds in order to produce a random text code.
The path to ImageMagick's 'convert' utility needs to be set below along with a preferred true-type font file to create the challenge.
The minimum and maximum values below are used as limits for the random number function used to create each unique image.
settings['validtime'] * 60));
$wpdb->query("DELETE from $wpdb->secureimage WHERE img_datetime < '$validdate'"); //clean up unused images
}
function comment_post($post_ID) {
global $wpdb, $user_ID;
$securitycode = md5($_POST['securitycode']);
$validdate = date('Y-m-d H:i:s', time() - ($this->settings['validtime'] * 60));
// If the user is not logged in check the security code
if ( !$user_ID ) {
// puke on an empty code
if ( '' == $securitycode )
die( __('Error: please enter the security code.') );
// verify the code against the database.
if (!$wpdb->get_var("SELECT img_name FROM $wpdb->secureimage WHERE img_name = '$securitycode' AND img_datetime > '$validdate'")) {
$wpdb->query("DELETE from $wpdb->comments WHERE comment_ID = $post_ID"); //roll back the comment post
die('Invalid security code. Press your browsers back button and try again.');
} else {
$wpdb->query("DELETE from $wpdb->secureimage WHERE img_name = '$securitycode'"); //were ok, delete the image from db
}
}
return $post_ID;
}
function comment_form($post_ID) {
global $wpdb, $user_ID;
// If the user is logged in, dont prompt for code
if (isset($user_ID))
return $post_ID;
$convertprg = $this->settings['convertpath'];
if (!file_exists($convertprg)) {
die(_e('Couldn\'t find your convert utility. Check that you have ImageMagick installed.', 'SecureImage'));
}
//Generate the random string
$chars = array("a","A","b","B","c","C","d","D","e","E","f","F","g","G","h","H","i","j","J",
"k","K","L","m","M","n","N","o","O","p","P","q","Q","r","R","s","S","t","T",
"u","U","v","V","w","W","x","X","y","Y","z","Z","1","2","3","4","5","6","7","8","9");
$textstr = '';
for ($i = 0, $length = rand($this->settings['lengthmin'], $this->settings['lengthmax']); $i < $length; $i++) {
$textstr .= $chars[rand(0, count($chars) - 1)];
}
// SET SESSION VARIABLE
$hashtext = md5($textstr);
//print $hashtext;
# prep font and color
$font = $this->settings['fontfile'];
$color = sprintf("#%02X%02X%02X", rand(0,160), rand(0,160), rand(0,160));
# image magick text gravities that we wanna use to position the text
$gravities = array('West', 'Center', 'East');
$gravity = $gravities[rand(0, count($gravities)-1)];
# modify the image according to the generated settings
$size = rand($this->settings['sizemin'], $this->settings['sizemax']);
$blur = rand($this->settings['blurmin'], $this->settings['blurmax']);
$angle = rand($this->settings['anglemin'], $this->settings['anglemax']);
$swirl = rand($this->settings['swirlmin'], $this->settings['swirlmax']);
$wave = rand($this->settings['wavemin'], $this->settings['wavemax']);
# prepare our image magick command
$cmd = $convertprg;
if (strlen($this->settings['fontfile'])>0) $cmd .= ' -font "/usr/share/fonts/truetype/freefont/FreeSans.ttf"';
$cmd .= ' -fill "'.$color.'"';
$cmd .= ' -pointsize '.$size;
$cmd .= ' -gravity "'.$gravity.'"';
#$cmd .= ' -draw \'text 0,0 "'.$textstr.'"\''; #doesn't work under windoze
$cmd .= ' -draw "text 0,0 \''.$textstr.'\'"';
$cmd .= ' -blur '.$blur;
$cmd .= ' -rotate '.$angle;
$cmd .= ' -swirl '.$swirl;
$cmd .= ' -wave '.$wave.'x80';
$cmd .= ' - - '; # - - for stdin/stdout redirect
#print $cmd;
// -blur