Enano CMS (1.1.x): comparison includes/captcha/engine

equal deleted inserted replaced

-:7eef739a5b81
+:6ae6e387a0e3
+<?php
+/************************************************************\
+*
+*		freeCap v1.4.1 Copyright 2005 Howard Yeend
+*		www.puremango.co.uk
+*
+*    This file is part of freeCap.
+*
+*    freeCap is free software; you can redistribute it and/or modify
+*    it under the terms of the GNU General Public License as published by
+*    the Free Software Foundation; either version 2 of the License, or
+*    (at your option) any later version.
+*
+*    freeCap is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU General Public License for more details.
+*
+*    You should have received a copy of the GNU General Public License
+*    along with freeCap; if not, write to the Free Software
+*    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*
+*
+\************************************************************/
+/**
+* A port of the freeCap captcha engine to Enano.
+*/
+class captcha_engine_freecap extends captcha_base
+{
+var $site_tags = array();
+var $tag_pos = 0;
+var $rand_func = "mt_rand";
+var $seed_func = "mt_srand";
+var $hash_func = "sha1";
+var $output = "png";
+var $use_dict = false;
+var $dict_location = "";
+var $max_word_length = 7;
+var $col_type = 1;
+var $max_attempts = 20;
+var $font_locations = Array();
+var $bg_type = 3;
+var $blur_bg = false;
+var $bg_images = Array();
+var $merge_type = 0;
+var $morph_bg = true;
+var $im, $im2, $im3;
+var $font_size = 36;
+var $debug = false;
+function __construct($s, $r = false)
+{
+parent::__construct($s, $r);
+// try to avoid the 'free p*rn' method of CAPTCHA circumvention
+// see en.wikipedia.org/wiki/CAPTCHA for more info
+// $this->site_tags[0] = "To avoid spam, please do NOT enter the text if";
+// $this->site_tags[1] = "this site is not puremango.co.uk";
+// or more simply:
+// $site_tags[0] = "for use only on puremango.co.uk";
+// reword or add lines as you please
+// or if you don't want any text:
+$this->site_tags = array();
+// where to write the above:
+// 0=top
+// 1=bottom
+// 2=both
+$this->tag_pos = 1;
+// functions to call for random number generation
+// mt_rand produces 'better' random numbers
+// but if your server doesn't support it, it's fine to use rand instead
+$this->rand_func = "mt_rand";
+$this->seed_func = "mt_srand";
+// which type of hash to use?
+// possible values: "sha1", "md5", "crc32"
+// sha1 supported by PHP4.3.0+
+// md5 supported by PHP3+
+// crc32 supported by PHP4.0.1+
+$this->hash_func = $this->session_fetch('hash_func', 'sha1');
+// store in session so can validate in form processor
+// image type:
+// possible values: "jpg", "png", "gif"
+// jpg doesn't support transparency (transparent bg option ends up white)
+// png isn't supported by old browsers (see http://www.libpng.org/pub/png/pngstatus.html)
+// gif may not be supported by your GD Lib.
+$this->output = "png";
+// 0=generate pseudo-random string, true=use dictionary
+// dictionary is easier to recognise
+// - both for humans and computers, so use random string if you're paranoid.
+$this->use_dict = false;
+// if your server is NOT set up to deny web access to files beginning ".ht"
+// then you should ensure the dictionary file is kept outside the web directory
+// eg: if www.foo.com/index.html points to c:\website\www\index.html
+// then the dictionary should be placed in c:\website\dict.txt
+// test your server's config by trying to access the dictionary through a web browser
+// you should NOT be able to view the contents.
+// can leave this blank if not using dictionary
+$this->dict_location = ENANO_ROOT . "/includes/captcha/dicts/default.php";
+// used to calculate image width, and for non-dictionary word generation
+$this->max_word_length = 7;
+// text colour
+// 0=one random colour for all letters
+// 1=different random colour for each letter
+$this->col_type = 1;
+// maximum times a user can refresh the image
+// on a 6500 word dictionary, I think 15-50 is enough to not annoy users and make BF unfeasble.
+// further notes re: BF attacks in "avoid brute force attacks" section, below
+// on the other hand, those attempting OCR will find the ability to request new images
+// very useful; if they can't crack one, just grab an easier target...
+// for the ultra-paranoid, setting it to <5 will still work for most users
+$this->max_attempts = 20;
+// list of fonts to use
+// font size should be around 35 pixels wide for each character.
+// you can use my GD fontmaker script at www.puremango.co.uk to create your own fonts
+// There are other programs to can create GD fonts, but my script allows a greater
+// degree of control over exactly how wide each character is, and is therefore
+// recommended for 'special' uses. For normal use of GD fonts,
+// the GDFontGenerator @ http://www.philiplb.de is excellent for convering ttf to GD
+// the fonts included with freeCap *only* include lowercase alphabetic characters
+// so are not suitable for most other uses
+// to increase security, you really should add other fonts
+$this->font_locations = Array(
+//ENANO_ROOT . "/includes/captcha/fonts/assimila.ttf",
+//ENANO_ROOT . "/includes/captcha/fonts/elephant.ttf",
+//ENANO_ROOT . "/includes/captcha/fonts/swash_normal.ttf",
+//ENANO_ROOT . "/includes/captcha/fonts/.ttf",
+//ENANO_ROOT . "/includes/captcha/fonts/trekker_regular.ttf"
+ENANO_ROOT . "/includes/captcha/fonts/FreeMonoBold.ttf",
+ENANO_ROOT . "/includes/captcha/fonts/FreeSerifBold.ttf",
+ENANO_ROOT . "/includes/captcha/fonts/LiberationSans-Bold.ttf",
+);
+// background:
+// 0=transparent (if jpg, white)
+// 1=white bg with grid
+// 2=white bg with squiggles
+// 3=morphed image blocks
+// 'random' background from v1.3 didn't provide any extra security (according to 2 independent experts)
+// many thanks to http://ocr-research.org.ua and http://sam.zoy.org/pwntcha/ for testing
+// for jpgs, 'transparent' is white
+$this->bg_type = 3;
+// should we blur the background? (looks nicer, makes text easier to read, takes longer)
+$this->blur_bg = false;
+// for bg_type 3, which images should we use?
+// if you add your own, make sure they're fairly 'busy' images (ie a lot of shapes in them)
+$this->bg_images = Array(
+ENANO_ROOT . "/includes/captcha/pics/freecap_im1.jpg",
+ENANO_ROOT . "/includes/captcha/pics/freecap_im2.jpg",
+ENANO_ROOT . "/includes/captcha/pics/freecap_im3.jpg",
+ENANO_ROOT . "/includes/captcha/pics/freecap_im4.jpg",
+ENANO_ROOT . "/includes/captcha/pics/allyourbase.jpg"
+);
+// for non-transparent backgrounds only:
+// if 0, merges CAPTCHA with bg
+// if 1, write CAPTCHA over bg
+$this->merge_type = 0;
+// should we morph the bg? (recommend yes, but takes a little longer to compute)
+$this->morph_bg = true;
+// you shouldn't need to edit anything below this, but it's extensively commented if you do want to play
+// have fun, and email me with ideas, or improvements to the code (very interested in speed improvements)
+// hope this script saves some spam :-)
+}
+//////////////////////////////////////////////////////
+////// Functions:
+//////////////////////////////////////////////////////
+function make_seed() {
+// from http://php.net/srand
+list($usec, $sec) = explode(' ', microtime());
+return (float) $sec + ((float) $usec * 100000);
+}
+function rand_color() {
+$rf =& $this->rand_func;
+if($this->bg_type==3)
+{
+// needs darker colour..
+return $rf(10,100);
+} else {
+return $rf(60,170);
+}
+}
+function myImageBlur($im)
+{
+// w00t. my very own blur function
+// in GD2, there's a gaussian blur function. bunch of bloody show-offs... :-)
+$width = imagesx($im);
+$height = imagesy($im);
+$temp_im = ImageCreateTrueColor($width,$height);
+$bg = ImageColorAllocate($temp_im,150,150,150);
+// preserves transparency if in orig image
+ImageColorTransparent($temp_im,$bg);
+// fill bg
+ImageFill($temp_im,0,0,$bg);
+// anything higher than 3 makes it totally unreadable
+// might be useful in a 'real' blur function, though (ie blurring pictures not text)
+$distance = 1;
+// use $distance=30 to have multiple copies of the word. not sure if this is useful.
+// blur by merging with itself at different x/y offsets:
+ImageCopyMerge($temp_im, $im, 0, 0, 0, $distance, $width, $height-$distance, 70);
+ImageCopyMerge($im, $temp_im, 0, 0, $distance, 0, $width-$distance, $height, 70);
+ImageCopyMerge($temp_im, $im, 0, $distance, 0, 0, $width, $height, 70);
+ImageCopyMerge($im, $temp_im, $distance, 0, 0, 0, $width, $height, 70);
+// remove temp image
+ImageDestroy($temp_im);
+return $im;
+}
+function sendImage($pic)
+{
+// output image with appropriate headers
+global $output,$im,$im2,$im3;
+// ENANO - obfuscation technique disabled
+// (this is for ethical reasons - ask dan at enanocms.org for information on why)
+// Basically it outputs an X-Captcha header showing freeCap version, etc. Unnecessary
+// header(base64_decode("WC1DYXB0Y2hhOiBmcmVlQ2FwIDEuNCAtIHd3dy5wdXJlbWFuZ28uY28udWs="));
+if ( $this->debug )
+{
+$x = imagesx($pic) - 70;
+$y = imagesy($pic) - 20;
+$code = $this->get_code();
+$red = ImageColorAllocateAlpha($pic, 0xAA, 0, 0, 72);
+ImageString($pic, 5, $x, $y, $code, $red);
+ImageString($pic, 5, 5, $y, "[debug mode]", $red);
+}
+switch($this->output)
+{
+// add other cases as desired
+case "jpg":
+header("Content-Type: image/jpeg");
+ImageJPEG($pic);
+break;
+case "gif":
+header("Content-Type: image/gif");
+ImageGIF($pic);
+break;
+case "png":
+default:
+header("Content-Type: image/png");
+ImagePNG($pic);
+break;
+}
+// kill GD images (removes from memory)
+ImageDestroy($this->im);
+ImageDestroy($this->im2);
+ImageDestroy($pic);
+if(!empty($this->im3))
+{
+ImageDestroy($this->im3);
+}
+exit();
+}
+function make_image()
+{
+//////////////////////////////////////////////////////
+////// Create Images + initialise a few things
+//////////////////////////////////////////////////////
+// seed random number generator
+// PHP 4.2.0+ doesn't need this, but lower versions will
+$this->seed_func($this->make_seed());
+// how faded should the bg be? (100=totally gone, 0=bright as the day)
+// to test how much protection the bg noise gives, take a screenshot of the freeCap image
+// and take it into a photo editor. play with contrast and brightness.
+// If you can remove most of the bg, then it's not a good enough percentage
+switch($this->bg_type)
+{
+case 0:
+break;
+case 1:
+case 2:
+$bg_fade_pct = 65;
+break;
+case 3:
+$bg_fade_pct = 50;
+break;
+}
+// slightly randomise the bg fade
+$bg_fade_pct += $this->rand_func(-2,2);
+// read each font and get font character widths
+// $font_widths = Array();
+// for($i=0 ; $i<sizeof($this->font_locations) ; $i++)
+// {
+//   $handle = fopen($this->font_locations[$i],"r");
+//   // read header of GD font, up to char width
+//   $c_wid = fread($handle,15);
+//   $font_widths[$i] = ord($c_wid{8})+ord($c_wid{9})+ord($c_wid{10})+ord($c_wid{11});
+//   fclose($handle);
+// }
+// modify image width depending on maximum possible length of word
+// you shouldn't need to use words > 6 chars in length really.
+$width = ($this->max_word_length*($this->font_size+10)+75);
+$height = 90;
+$this->im = ImageCreateTrueColor($width, $height);
+$this->im2 = ImageCreateTrueColor($width, $height);
+////////////////////////////////////////////////////////
+// GENERATE IMAGE                                     //
+////////////////////////////////////////////////////////
+$word = $this->get_code();
+// save hash of word for comparison
+// using hash so that if there's an insecurity elsewhere (eg on the form processor),
+// an attacker could only get the hash
+// also, shared servers usually give all users access to the session files
+// echo `ls /tmp`; and echo `more /tmp/someone_elses_session_file`; usually work
+// so even if your site is 100% secure, someone else's site on your server might not be
+// hence, even if attackers can read the session file, they can't get the freeCap word
+// (though most hashes are easy to brute force for simple strings)
+//////////////////////////////////////////////////////
+////// Fill BGs and Allocate Colours:
+//////////////////////////////////////////////////////
+// set tag colour
+// have to do this before any distortion
+// (otherwise colour allocation fails when bg type is 1)
+$tag_col = ImageColorAllocate($this->im,10,10,10);
+$site_tag_col2 = ImageColorAllocate($this->im2,0,0,0);
+// set debug colours (text colours are set later)
+$debug = ImageColorAllocate($this->im, 255, 0, 0);
+$debug2 = ImageColorAllocate($this->im2, 255, 0, 0);
+// set background colour (can change to any colour not in possible $text_col range)
+// it doesn't matter as it'll be transparent or coloured over.
+// if you're using bg_type 3, you might want to try to ensure that the color chosen
+// below doesn't appear too much in any of your background images.
+$bg = ImageColorAllocate($this->im, 254, 254, 254);
+$bg2 = ImageColorAllocate($this->im2, 254, 254, 254);
+// set transparencies
+ImageColorTransparent($this->im,$bg);
+// im2 transparent to allow characters to overlap slightly while morphing
+ImageColorTransparent($this->im2,$bg2);
+// fill backgrounds
+ImageFill($this->im,0,0,$bg);
+ImageFill($this->im2,0,0,$bg2);
+if($this->bg_type!=0)
+{
+// generate noisy background, to be merged with CAPTCHA later
+// any suggestions on how best to do this much appreciated
+// sample code would be even better!
+// I'm not an OCR expert (hell, I'm not even an image expert; puremango.co.uk was designed in MsPaint)
+// so the noise models are based around my -guesswork- as to what would make it hard for an OCR prog
+// ideally, the character obfuscation would be strong enough not to need additional background noise
+// in any case, I hope at least one of the options given here provide some extra security!
+$this->im3 = ImageCreateTrueColor($width,$height);
+$temp_bg = ImageCreateTrueColor($width*1.5,$height*1.5);
+$bg3 = ImageColorAllocate($this->im3,255,255,255);
+ImageFill($this->im3,0,0,$bg3);
+$temp_bg_col = ImageColorAllocate($temp_bg,255,255,255);
+ImageFill($temp_bg,0,0,$temp_bg_col);
+// we draw all noise onto temp_bg
+// then if we're morphing, merge from temp_bg to im3
+// or if not, just copy a $widthx$height portion of $temp_bg to $this->im3
+// temp_bg is much larger so that when morphing, the edges retain the noise.
+if($this->bg_type==1)
+{
+// grid bg:
+// draw grid on x
+for($i=$this->rand_func(6,20) ; $i<$width*2 ; $i+=$this->rand_func(10,25))
+{
+ImageSetThickness($temp_bg,$this->rand_func(2,6));
+$text_r = $this->rand_func(100,150);
+$text_g = $this->rand_func(100,150);
+$text_b = $this->rand_func(100,150);
+$text_colour3 = ImageColorAllocate($temp_bg, $text_r, $text_g, $text_b);
+ImageLine($temp_bg,$i,0,$i,$height*2,$text_colour3);
+}
+// draw grid on y
+for($i=$this->rand_func(6,20) ; $i<$height*2 ; $i+=$this->rand_func(10,25))
+{
+ImageSetThickness($temp_bg,$this->rand_func(2,6));
+$text_r = $this->rand_func(100,150);
+$text_g = $this->rand_func(100,150);
+$text_b = $this->rand_func(100,150);
+$text_colour3 = ImageColorAllocate($temp_bg, $text_r, $text_g, $text_b);
+ImageLine($temp_bg,0,$i,$width*2, $i ,$text_colour3);
+}
+} else if($this->bg_type==2) {
+// draw squiggles!
+$bg3 = ImageColorAllocate($this->im3,255,255,255);
+ImageFill($this->im3,0,0,$bg3);
+ImageSetThickness($temp_bg,4);
+for($i=0 ; $i<strlen($word)+1 ; $i++)
+{
+$text_r = $this->rand_func(100,150);
+$text_g = $this->rand_func(100,150);
+$text_b = $this->rand_func(100,150);
+$text_colour3 = ImageColorAllocate($temp_bg, $text_r, $text_g, $text_b);
+$points = Array();
+// draw random squiggle for each character
+// the longer the loop, the more complex the squiggle
+// keep random so OCR can't say "if found shape has 10 points, ignore it"
+// each squiggle will, however, be a closed shape, so OCR could try to find
+// line terminations and start from there. (I don't think they're that advanced yet..)
+for($j=1 ; $j<$this->rand_func(5,10) ; $j++)
+{
+$points[] = $this->rand_func(1*(20*($i+1)),1*(50*($i+1)));
+$points[] = $this->rand_func(30,$height+30);
+}
+ImagePolygon($temp_bg,$points,intval(sizeof($points)/2),$text_colour3);
+}
+} else if($this->bg_type==3) {
+// take random chunks of $this->bg_images and paste them onto the background
+for($i=0 ; $i<sizeof($this->bg_images) ; $i++)
+{
+// read each image and its size
+$temp_im[$i] = ImageCreateFromJPEG($this->bg_images[$i]);
+$temp_width[$i] = imagesx($temp_im[$i]);
+$temp_height[$i] = imagesy($temp_im[$i]);
+}
+$blocksize = $this->rand_func(20,60);
+for($i=0 ; $i<$width*2 ; $i+=$blocksize)
+{
+// could randomise blocksize here... hardly matters
+for($j=0 ; $j<$height*2 ; $j+=$blocksize)
+{
+$this->image_index = $this->rand_func(0,sizeof($temp_im)-1);
+$cut_x = $this->rand_func(0,$temp_width[$this->image_index]-$blocksize);
+$cut_y = $this->rand_func(0,$temp_height[$this->image_index]-$blocksize);
+ImageCopy($temp_bg, $temp_im[$this->image_index], $i, $j, $cut_x, $cut_y, $blocksize, $blocksize);
+}
+}
+for($i=0 ; $i<sizeof($temp_im) ; $i++)
+{
+// remove bgs from memory
+ImageDestroy($temp_im[$i]);
+}
+// for debug:
+//sendImage($temp_bg);
+}
+// for debug:
+//sendImage($this->im3);
+if($this->morph_bg)
+{
+// morph background
+// we do this separately to the main text morph because:
+// a) the main text morph is done char-by-char, this is done across whole image
+// b) if an attacker could un-morph the bg, it would un-morph the CAPTCHA
+// hence bg is morphed differently to text
+// why do we morph it at all? it might make it harder for an attacker to remove the background
+// morph_chunk 1 looks better but takes longer
+// this is a different and less perfect morph than the one we do on the CAPTCHA
+// occasonally you get some dark background showing through around the edges
+// it doesn't need to be perfect as it's only the bg.
+$morph_chunk = $this->rand_func(1,5);
+$morph_y = 0;
+for($x=0 ; $x<$width ; $x+=$morph_chunk)
+{
+$morph_chunk = $this->rand_func(1,5);
+$morph_y += $this->rand_func(-1,1);
+ImageCopy($this->im3, $temp_bg, $x, 0, $x+30, 30+$morph_y, $morph_chunk, $height*2);
+}
+ImageCopy($temp_bg, $this->im3, 0, 0, 0, 0, $width, $height);
+$morph_x = 0;
+for($y=0 ; $y<=$height; $y+=$morph_chunk)
+{
+$morph_chunk = $this->rand_func(1,5);
+$morph_x += $this->rand_func(-1,1);
+ImageCopy($this->im3, $temp_bg, $morph_x, $y, 0, $y, $width, $morph_chunk);
+}
+} else {
+// just copy temp_bg onto im3
+ImageCopy($this->im3,$temp_bg,0,0,30,30,$width,$height);
+}
+ImageDestroy($temp_bg);
+if($this->blur_bg)
+{
+$this->myImageBlur($this->im3);
+}
+}
+// for debug:
+//sendImage($this->im3);
+//////////////////////////////////////////////////////
+////// Write Word
+//////////////////////////////////////////////////////
+// write word in random starting X position
+$word_start_x = $this->rand_func(5,32);
+// y positions jiggled about later
+$word_start_y = 50;
+// use last pixelwidth
+$font_pixelwidth = $this->font_size + 10;
+if($this->col_type==0)
+{
+$text_r = $this->rand_color();
+$text_g = $this->rand_color();
+$text_b = $this->rand_color();
+$text_colour2 = ImageColorAllocate($this->im2, $text_r, $text_g, $text_b);
+}
+// write each char in different font
+for($i=0 ; $i<strlen($word) ; $i++)
+{
+if($this->col_type==1)
+{
+$text_r = $this->rand_color();
+$text_g = $this->rand_color();
+$text_b = $this->rand_color();
+$text_colour2 = ImageColorAllocate($this->im2, $text_r, $text_g, $text_b);
+}
+$j = $this->rand_func(0,sizeof($this->font_locations)-1);
+// $font = ImageLoadFont($this->font_locations[$j]);
+// ImageString($this->im2, $font, $word_start_x+($font_widths[$j]*$i), $word_start_y, $word{$i}, $text_colour2);
+ImageTTFText($this->im2, $this->font_size, 0, $word_start_x+(($font_pixelwidth)*$i), $word_start_y, $text_colour2, $this->font_locations[$j], $word{$i});
+}
+// for debug:
+// $this->sendImage($this->im2);
+//////////////////////////////////////////////////////
+////// Morph Image:
+//////////////////////////////////////////////////////
+// calculate how big the text is in pixels
+// (so we only morph what we need to)
+$word_pix_size = $word_start_x+(strlen($word)*$font_pixelwidth);
+// firstly move each character up or down a bit:
+$y_pos = 0;
+for($i=$word_start_x ; $i<$word_pix_size ; $i+=$font_pixelwidth)
+{
+// move on Y axis
+// deviates at least 4 pixels between each letter
+$prev_y = $y_pos;
+do{
+$y_pos = $this->rand_func(-5,5);
+} while($y_pos<$prev_y+2 && $y_pos>$prev_y-2);
+ImageCopy($this->im, $this->im2, $i, $y_pos, $i, 0, $font_pixelwidth, $height);
+// for debug:
+// ImageRectangle($this->im,$i,$y_pos+10,$i+$font_pixelwidth,$y_pos+70,$debug);
+}
+// for debug:
+// $this->sendImage($this->im);
+ImageFilledRectangle($this->im2,0,0,$width,$height,$bg2);
+// randomly morph each character individually on x-axis
+// this is where the main distortion happens
+// massively improved since v1.2
+$y_chunk = 1;
+$morph_factor = 1;
+$morph_x = 0;
+for($j=0 ; $j<strlen($word) ; $j++)
+{
+$y_pos = 0;
+for($i=0 ; $i<=$height; $i+=$y_chunk)
+{
+$orig_x = $word_start_x+($j*$font_pixelwidth);
+// morph x += so that instead of deviating from orig x each time, we deviate from where we last deviated to
+// get it? instead of a zig zag, we get more of a sine wave.
+// I wish we could deviate more but it looks crap if we do.
+$morph_x += $this->rand_func(-$morph_factor,$morph_factor);
+// had to change this to ImageCopyMerge when starting using ImageCreateTrueColor
+// according to the manual; "when (pct is) 100 this function behaves identically to imagecopy()"
+// but this is NOT true when dealing with transparencies...
+ImageCopyMerge($this->im2, $this->im, $orig_x+$morph_x, $i+$y_pos, $orig_x, $i, $font_pixelwidth, $y_chunk, 100);
+// for debug:
+//ImageLine($this->im2, $orig_x+$morph_x, $i, $orig_x+$morph_x+1, $i+$y_chunk, $debug2);
+//ImageLine($this->im2, $orig_x+$morph_x+$font_pixelwidth, $i, $orig_x+$morph_x+$font_pixelwidth+1, $i+$y_chunk, $debug2);
+}
+}
+// for debug:
+//sendImage($this->im2);
+ImageFilledRectangle($this->im,0,0,$width,$height,$bg);
+// now do the same on the y-axis
+// (much easier because we can just do it across the whole image, don't have to do it char-by-char)
+$y_pos = 0;
+$x_chunk = 1;
+for($i=0 ; $i<=$width ; $i+=$x_chunk)
+{
+// can result in image going too far off on Y-axis;
+// not much I can do about that, apart from make image bigger
+// again, I wish I could do 1.5 pixels
+$y_pos += $this->rand_func(-1,1);
+ImageCopy($this->im, $this->im2, $i, $y_pos, $i, 0, $x_chunk, $height);
+// for debug:
+//ImageLine($this->im,$i+$x_chunk,0,$i+$x_chunk,100,$debug);
+//ImageLine($this->im,$i,$y_pos+25,$i+$x_chunk,$y_pos+25,$debug);
+}
+// for debug:
+//sendImage($this->im);
+// blur edges:
+// doesn't really add any security, but looks a lot nicer, and renders text a little easier to read
+// for humans (hopefully not for OCRs, but if you know better, feel free to disable this function)
+// (and if you do, let me know why)
+$this->myImageBlur($this->im);
+// for debug:
+//sendImage($this->im);
+if($this->output!="jpg" && $this->bg_type==0)
+{
+// make background transparent
+ImageColorTransparent($this->im,$bg);
+}
+//////////////////////////////////////////////////////
+////// Try to avoid 'free p*rn' style CAPTCHA re-use
+//////////////////////////////////////////////////////
+// ('*'ed to stop my site coming up for certain keyword searches on google)
+// can obscure CAPTCHA word in some cases..
+// write site tags 'shining through' the morphed image
+ImageFilledRectangle($this->im2,0,0,$width,$height,$bg2);
+if(is_array($this->site_tags))
+{
+for($i=0 ; $i<sizeof($this->site_tags) ; $i++)
+{
+// ensure tags are centered
+$tag_width = strlen($this->site_tags[$i])*6;
+// write tag is chosen position
+if($this->tag_pos==0 || $this->tag_pos==2)
+{
+// write at top
+ImageString($this->im2, 2, intval($width/2)-intval($tag_width/2), (10*$i), $this->site_tags[$i], $site_tag_col2);
+}
+if($this->tag_pos==1 || $this->tag_pos==2)
+{
+// write at bottom
+ImageString($this->im2, 2, intval($width/2)-intval($tag_width/2), ($height-34+($i*10)), $this->site_tags[$i], $site_tag_col2);
+}
+}
+}
+ImageCopyMerge($this->im2,$this->im,0,0,0,0,$width,$height,80);
+ImageCopy($this->im,$this->im2,0,0,0,0,$width,$height);
+// for debug:
+//sendImage($this->im);
+//////////////////////////////////////////////////////
+////// Merge with obfuscated background
+//////////////////////////////////////////////////////
+if($this->bg_type!=0)
+{
+// merge bg image with CAPTCHA image to create smooth background
+// fade bg:
+if($this->bg_type!=3)
+{
+$temp_im = ImageCreateTrueColor($width,$height);
+$white = ImageColorAllocate($temp_im,255,255,255);
+ImageFill($temp_im,0,0,$white);
+ImageCopyMerge($this->im3,$temp_im,0,0,0,0,$width,$height,$bg_fade_pct);
+// for debug:
+//sendImage($this->im3);
+ImageDestroy($temp_im);
+$c_fade_pct = 50;
+} else {
+$c_fade_pct = $bg_fade_pct;
+}
+// captcha over bg:
+// might want to not blur if using this method
+// otherwise leaves white-ish border around each letter
+if($this->merge_type==1)
+{
+ImageCopyMerge($this->im3,$this->im,0,0,0,0,$width,$height,100);
+ImageCopy($this->im,$this->im3,0,0,0,0,$width,$height);
+} else {
+// bg over captcha:
+ImageCopyMerge($this->im,$this->im3,0,0,0,0,$width,$height,$c_fade_pct);
+}
+}
+// for debug:
+//sendImage($this->im);
+//////////////////////////////////////////////////////
+////// Write tags, remove variables and output!
+//////////////////////////////////////////////////////
+// tag it
+// feel free to remove/change
+// but if it's not essential I'd appreciate you leaving it
+// after all, I've put a lot of work into this and am giving it away for free
+// the least you could do is give me credit (or buy me stuff from amazon!)
+// but I understand that in professional environments, your boss might not like this tag
+// so that's cool.
+$tag_str = "";
+// for debug:
+//$tag_str = "[".$word."]";
+// ensure tag is right-aligned
+$tag_width = strlen($tag_str)*6;
+// write tag
+ImageString($this->im, 2, $width-$tag_width, $height-13, $tag_str, $tag_col);
+// unset all sensetive vars
+// in case someone include()s this file on a shared server
+// you might think this unneccessary, as it exit()s
+// but by using register_shutdown_function
+// on a -very- insecure shared server, they -might- be able to get the word
+unset($word);
+// the below aren't really essential, but might aid an OCR attack if discovered.
+// so we unset them
+// output final image :-)
+$this->sendImage($this->im);
+// (sendImage also destroys all used images)
+}
+function rand_func($s, $m)
+{
+global $_starttime;
+$tn = microtime_float() - $_starttime;
+if ( $tn > 5 )
+{
+echo '<pre>';
+enano_debug_print_backtrace();
+echo '</pre>';
+exit;
+}
+$rf =& $this->rand_func;
+return $rf($s, $m);
+}
+function seed_func($s)
+{
+$rf =& $this->seed_func;
+return $rf($s);
+}
+function hash_func($s)
+{
+$rf =& $this->hash_func;
+return $rf($s);
+}
+}

changeset 401	6ae6e387a0e3
child 558	fd082123f2f4