Fix various compatibility issues with PHP 8

libs/Captcha/CaptchaBuilder.php

@@ -0,0 +1,739 @@
+<?php
+
+namespace Gregwar\Captcha;
+
+use \Exception;
+
+/**
+ * Builds a new captcha image
+ * Uses the fingerprint parameter, if one is passed, to generate the same image
+ *
+ * @author Gregwar <g.passault@gmail.com>
+ * @author Jeremy Livingston <jeremy.j.livingston@gmail.com>
+ */
+class CaptchaBuilder implements CaptchaBuilderInterface
+{
+    /**
+     * @var array
+     */
+    protected $fingerprint = array();
+
+    /**
+     * @var bool
+     */
+    protected $useFingerprint = false;
+
+    /**
+     * @var array
+     */
+    protected $textColor = array();
+
+    /**
+     * @var array
+     */
+    protected $lineColor = null;
+
+    /**
+     * @var array
+     */
+    protected $backgroundColor = null;
+
+    /**
+     * @var array
+     */
+    protected $backgroundImages = array();
+
+    /**
+     * @var resource
+     */
+    protected $contents = null;
+
+    /**
+     * @var string
+     */
+    protected $phrase = null;
+
+    /**
+     * @var PhraseBuilderInterface
+     */
+    protected $builder;
+
+    /**
+     * @var bool
+     */
+    protected $distortion = true;
+
+    /**
+     * The maximum number of lines to draw in front of
+     * the image. null - use default algorithm
+     */
+    protected $maxFrontLines = null;
+
+    /**
+     * The maximum number of lines to draw behind
+     * the image. null - use default algorithm
+     */
+    protected $maxBehindLines = null;
+
+    /**
+     * The maximum angle of char
+     */
+    protected $maxAngle = 8;
+
+    /**
+     * The maximum offset of char
+     */
+    protected $maxOffset = 5;
+
+    /**
+     * Is the interpolation enabled ?
+     *
+     * @var bool
+     */
+    protected $interpolation = true;
+
+    /**
+     * Ignore all effects
+     *
+     * @var bool
+     */
+    protected $ignoreAllEffects = false;
+
+    /**
+     * Allowed image types for the background images
+     *
+     * @var array
+     */
+    protected $allowedBackgroundImageTypes = array('image/png', 'image/jpeg', 'image/gif');
+
+    /**
+     * The image contents
+     */
+    public function getContents()
+    {
+        return $this->contents;
+    }
+
+    /**
+     * Enable/Disables the interpolation
+     *
+     * @param $interpolate bool  True to enable, false to disable
+     *
+     * @return CaptchaBuilder
+     */
+    public function setInterpolation($interpolate = true)
+    {
+        $this->interpolation = $interpolate;
+
+        return $this;
+    }
+
+    /**
+     * Temporary dir, for OCR check
+     */
+    public $tempDir = 'temp/';
+
+    public function __construct($phrase = null, PhraseBuilderInterface $builder = null)
+    {
+        if ($builder === null) {
+            $this->builder = new PhraseBuilder;
+        } else {
+            $this->builder = $builder;
+        }
+        
+        $this->phrase = is_string($phrase) ? $phrase : $this->builder->build($phrase);
+    }
+
+    /**
+     * Setting the phrase
+     */
+    public function setPhrase($phrase)
+    {
+        $this->phrase = (string) $phrase;
+    }
+
+    /**
+     * Enables/disable distortion
+     */
+    public function setDistortion($distortion)
+    {
+        $this->distortion = (bool) $distortion;
+
+        return $this;
+    }
+
+    public function setMaxBehindLines($maxBehindLines)
+    {
+        $this->maxBehindLines = $maxBehindLines;
+
+        return $this;
+    }
+
+    public function setMaxFrontLines($maxFrontLines)
+    {
+        $this->maxFrontLines = $maxFrontLines;
+
+        return $this;
+    }
+
+    public function setMaxAngle($maxAngle)
+    {
+        $this->maxAngle = $maxAngle;
+
+        return $this;
+    }
+
+    public function setMaxOffset($maxOffset)
+    {
+        $this->maxOffset = $maxOffset;
+
+        return $this;
+    }
+
+    /**
+     * Gets the captcha phrase
+     */
+    public function getPhrase()
+    {
+        return $this->phrase;
+    }
+
+    /**
+     * Returns true if the given phrase is good
+     */
+    public function testPhrase($phrase)
+    {
+        return ($this->builder->niceize($phrase) == $this->builder->niceize($this->getPhrase()));
+    }
+
+    /**
+     * Instantiation
+     */
+    public static function create($phrase = null)
+    {
+        return new self($phrase);
+    }
+
+    /**
+     * Sets the text color to use
+     */
+    public function setTextColor($r, $g, $b)
+    {
+        $this->textColor = array($r, $g, $b);
+
+        return $this;
+    }
+
+    /**
+     * Sets the background color to use
+     */
+    public function setBackgroundColor($r, $g, $b)
+    {
+        $this->backgroundColor = array($r, $g, $b);
+
+        return $this;
+    }
+
+    public function setLineColor($r, $g, $b)
+    {
+        $this->lineColor = array($r, $g, $b);
+
+        return $this;
+    }
+
+    /**
+     * Sets the ignoreAllEffects value
+     *
+     * @param bool $ignoreAllEffects
+     * @return CaptchaBuilder
+     */
+    public function setIgnoreAllEffects($ignoreAllEffects)
+    {
+        $this->ignoreAllEffects = $ignoreAllEffects;
+
+        return $this;
+    }
+
+    /**
+     * Sets the list of background images to use (one image is randomly selected)
+     */
+    public function setBackgroundImages(array $backgroundImages)
+    {
+        $this->backgroundImages = $backgroundImages;
+
+        return $this;
+    }
+
+    /**
+     * Draw lines over the image
+     */
+    protected function drawLine($image, $width, $height, $tcol = null)
+    {
+        if ($this->lineColor === null) {
+            $red = $this->rand(100, 255);
+            $green = $this->rand(100, 255);
+            $blue = $this->rand(100, 255);
+        } else {
+            $red = $this->lineColor[0];
+            $green = $this->lineColor[1];
+            $blue = $this->lineColor[2];
+        }
+
+        if ($tcol === null) {
+            $tcol = imagecolorallocate($image, $red, $green, $blue);
+        }
+
+        if ($this->rand(0, 1)) { // Horizontal
+            $Xa   = $this->rand(0, $width/2);
+            $Ya   = $this->rand(0, $height);
+            $Xb   = $this->rand($width/2, $width);
+            $Yb   = $this->rand(0, $height);
+        } else { // Vertical
+            $Xa   = $this->rand(0, $width);
+            $Ya   = $this->rand(0, $height/2);
+            $Xb   = $this->rand(0, $width);
+            $Yb   = $this->rand($height/2, $height);
+        }
+        imagesetthickness($image, $this->rand(1, 3));
+        imageline($image, $Xa, $Ya, $Xb, $Yb, $tcol);
+    }
+
+    /**
+     * Apply some post effects
+     */
+    protected function postEffect($image)
+    {
+        if (!function_exists('imagefilter')) {
+            return;
+        }
+
+        if ($this->backgroundColor != null || $this->textColor != null) {
+            return;
+        }
+
+        // Negate ?
+        if ($this->rand(0, 1) == 0) {
+            imagefilter($image, IMG_FILTER_NEGATE);
+        }
+
+        // Edge ?
+        if ($this->rand(0, 10) == 0) {
+            imagefilter($image, IMG_FILTER_EDGEDETECT);
+        }
+
+        // Contrast
+        imagefilter($image, IMG_FILTER_CONTRAST, $this->rand(-50, 10));
+
+        // Colorize
+        if ($this->rand(0, 5) == 0) {
+            imagefilter($image, IMG_FILTER_COLORIZE, $this->rand(-80, 50), $this->rand(-80, 50), $this->rand(-80, 50));
+        }
+    }
+
+    /**
+     * Writes the phrase on the image
+     */
+    protected function writePhrase($image, $phrase, $font, $width, $height)
+    {
+        $length = mb_strlen($phrase);
+        if ($length === 0) {
+            return \imagecolorallocate($image, 0, 0, 0);
+        }
+
+        // Gets the text size and start position
+        $size = $width / $length - $this->rand(0, 3) - 1;
+        $box = \imagettfbbox($size, 0, $font, $phrase);
+        $textWidth = $box[2] - $box[0];
+        $textHeight = $box[1] - $box[7];
+        $x = ($width - $textWidth) / 2;
+        $y = ($height - $textHeight) / 2 + $size;
+
+        if (!$this->textColor) {
+            $textColor = array($this->rand(0, 150), $this->rand(0, 150), $this->rand(0, 150));
+        } else {
+            $textColor = $this->textColor;
+        }
+        $col = \imagecolorallocate($image, $textColor[0], $textColor[1], $textColor[2]);
+
+        // Write the letters one by one, with random angle
+        for ($i=0; $i<$length; $i++) {
+            $symbol = mb_substr($phrase, $i, 1);
+            $box = \imagettfbbox($size, 0, $font, $symbol);
+            $w = $box[2] - $box[0];
+            $angle = $this->rand(-$this->maxAngle, $this->maxAngle);
+            $offset = $this->rand(-$this->maxOffset, $this->maxOffset);
+            \imagettftext($image, (float) $size, (float) $angle, (int) $x, (int) $y + $offset, (int) $col, (string) $font, (string) $symbol);
+            $x += $w;
+        }
+
+        return $col;
+    }
+
+    /**
+     * Try to read the code against an OCR
+     */
+    public function isOCRReadable()
+    {
+        if (!is_dir($this->tempDir)) {
+            @mkdir($this->tempDir, 0755, true);
+        }
+
+        $tempj = $this->tempDir . uniqid('captcha', true) . '.jpg';
+        $tempp = $this->tempDir . uniqid('captcha', true) . '.pgm';
+
+        $this->save($tempj);
+        shell_exec("convert $tempj $tempp");
+        $value = trim(strtolower(shell_exec("ocrad $tempp")));
+
+        @unlink($tempj);
+        @unlink($tempp);
+
+        return $this->testPhrase($value);
+    }
+
+    /**
+     * Builds while the code is readable against an OCR
+     */
+    public function buildAgainstOCR($width = 150, $height = 40, $font = null, $fingerprint = null)
+    {
+        do {
+            $this->build($width, $height, $font, $fingerprint);
+        } while ($this->isOCRReadable());
+    }
+
+    /**
+     * Generate the image
+     */
+    public function build($width = 150, $height = 40, $font = null, $fingerprint = null)
+    {
+        if (null !== $fingerprint) {
+            $this->fingerprint = $fingerprint;
+            $this->useFingerprint = true;
+        } else {
+            $this->fingerprint = array();
+            $this->useFingerprint = false;
+        }
+
+        if ($font === null) {
+            $font = __DIR__ . '/Font/captcha'.$this->rand(0, 5).'.ttf';
+        }
+
+        if (empty($this->backgroundImages)) {
+            // if background images list is not set, use a color fill as a background
+            $image   = imagecreatetruecolor($width, $height);
+            if ($this->backgroundColor == null) {
+                $bg = imagecolorallocate($image, $this->rand(200, 255), $this->rand(200, 255), $this->rand(200, 255));
+            } else {
+                $color = $this->backgroundColor;
+                $bg = imagecolorallocate($image, $color[0], $color[1], $color[2]);
+            }
+            $this->background = $bg;
+            imagefill($image, 0, 0, $bg);
+        } else {
+            // use a random background image
+            $randomBackgroundImage = $this->backgroundImages[rand(0, count($this->backgroundImages)-1)];
+
+            $imageType = $this->validateBackgroundImage($randomBackgroundImage);
+
+            $image = $this->createBackgroundImageFromType($randomBackgroundImage, $imageType);
+        }
+
+        // Apply effects
+        if (!$this->ignoreAllEffects) {
+            $square = $width * $height;
+            $effects = $this->rand($square/3000, $square/2000);
+
+            // set the maximum number of lines to draw in front of the text
+            if ($this->maxBehindLines != null && $this->maxBehindLines > 0) {
+                $effects = min($this->maxBehindLines, $effects);
+            }
+
+            if ($this->maxBehindLines !== 0) {
+                for ($e = 0; $e < $effects; $e++) {
+                    $this->drawLine($image, $width, $height);
+                }
+            }
+        }
+
+        // Write CAPTCHA text
+        $color = $this->writePhrase($image, $this->phrase, $font, $width, $height);
+
+        // Apply effects
+        if (!$this->ignoreAllEffects) {
+            $square = $width * $height;
+            $effects = $this->rand($square/3000, $square/2000);
+
+            // set the maximum number of lines to draw in front of the text
+            if ($this->maxFrontLines != null && $this->maxFrontLines > 0) {
+                $effects = min($this->maxFrontLines, $effects);
+            }
+
+            if ($this->maxFrontLines !== 0) {
+                for ($e = 0; $e < $effects; $e++) {
+                    $this->drawLine($image, $width, $height, $color);
+                }
+            }
+        }
+
+        // Distort the image
+        if ($this->distortion && !$this->ignoreAllEffects) {
+            $image = $this->distort($image, $width, $height, $bg);
+        }
+
+        // Post effects
+        if (!$this->ignoreAllEffects) {
+            $this->postEffect($image);
+        }
+
+        $this->contents = $image;
+
+        return $this;
+    }
+
+    /**
+     * Distorts the image
+     */
+    public function distort($image, $width, $height, $bg)
+    {
+        $contents = imagecreatetruecolor($width, $height);
+        $X          = $this->rand(0, $width);
+        $Y          = $this->rand(0, $height);
+        $phase      = $this->rand(0, 10);
+        $scale      = 1.1 + $this->rand(0, 10000) / 30000;
+        for ($x = 0; $x < $width; $x++) {
+            for ($y = 0; $y < $height; $y++) {
+                $Vx = $x - $X;
+                $Vy = $y - $Y;
+                $Vn = sqrt($Vx * $Vx + $Vy * $Vy);
+
+                if ($Vn != 0) {
+                    $Vn2 = $Vn + 4 * sin($Vn / 30);
+                    $nX  = $X + ($Vx * $Vn2 / $Vn);
+                    $nY  = $Y + ($Vy * $Vn2 / $Vn);
+                } else {
+                    $nX = $X;
+                    $nY = $Y;
+                }
+                $nY = $nY + $scale * sin($phase + $nX * 0.2);
+
+                if ($this->interpolation) {
+                    $p = $this->interpolate(
+                        $nX - floor($nX),
+                        $nY - floor($nY),
+                        $this->getCol($image, floor($nX), floor($nY), $bg),
+                        $this->getCol($image, ceil($nX), floor($nY), $bg),
+                        $this->getCol($image, floor($nX), ceil($nY), $bg),
+                        $this->getCol($image, ceil($nX), ceil($nY), $bg)
+                    );
+                } else {
+                    $p = $this->getCol($image, round($nX), round($nY), $bg);
+                }
+
+                if ($p == 0) {
+                    $p = $bg;
+                }
+
+                imagesetpixel($contents, $x, $y, $p);
+            }
+        }
+
+        return $contents;
+    }
+
+    /**
+     * Saves the Captcha to a jpeg file
+     */
+    public function save($filename, $quality = 90)
+    {
+        imagejpeg($this->contents, $filename, $quality);
+    }
+
+    /**
+     * Gets the image GD
+     */
+    public function getGd()
+    {
+        return $this->contents;
+    }
+
+    /**
+     * Gets the image contents
+     */
+    public function get($quality = 90)
+    {
+        ob_start();
+        $this->output($quality);
+
+        return ob_get_clean();
+    }
+
+    /**
+     * Gets the HTML inline base64
+     */
+    public function inline($quality = 90)
+    {
+        return 'data:image/jpeg;base64,' . base64_encode($this->get($quality));
+    }
+
+    /**
+     * Outputs the image
+     */
+    public function output($quality = 90)
+    {
+        imagejpeg($this->contents, null, $quality);
+    }
+
+    /**
+     * @return array
+     */
+    public function getFingerprint()
+    {
+        return $this->fingerprint;
+    }
+
+    /**
+     * Returns a random number or the next number in the
+     * fingerprint
+     */
+    protected function rand($min, $max)
+    {
+        if (!is_array($this->fingerprint)) {
+            $this->fingerprint = array();
+        }
+
+        if ($this->useFingerprint) {
+            $value = current($this->fingerprint);
+            next($this->fingerprint);
+        } else {
+            $value = mt_rand($min, $max);
+            $this->fingerprint[] = $value;
+        }
+
+        return $value;
+    }
+
+    /**
+     * @param $x
+     * @param $y
+     * @param $nw
+     * @param $ne
+     * @param $sw
+     * @param $se
+     *
+     * @return int
+     */
+    protected function interpolate($x, $y, $nw, $ne, $sw, $se)
+    {
+        list($r0, $g0, $b0) = $this->getRGB($nw);
+        list($r1, $g1, $b1) = $this->getRGB($ne);
+        list($r2, $g2, $b2) = $this->getRGB($sw);
+        list($r3, $g3, $b3) = $this->getRGB($se);
+
+        $cx = 1.0 - $x;
+        $cy = 1.0 - $y;
+
+        $m0 = $cx * $r0 + $x * $r1;
+        $m1 = $cx * $r2 + $x * $r3;
+        $r  = (int) ($cy * $m0 + $y * $m1);
+
+        $m0 = $cx * $g0 + $x * $g1;
+        $m1 = $cx * $g2 + $x * $g3;
+        $g  = (int) ($cy * $m0 + $y * $m1);
+
+        $m0 = $cx * $b0 + $x * $b1;
+        $m1 = $cx * $b2 + $x * $b3;
+        $b  = (int) ($cy * $m0 + $y * $m1);
+
+        return ($r << 16) | ($g << 8) | $b;
+    }
+
+    /**
+     * @param $image
+     * @param $x
+     * @param $y
+     *
+     * @return int
+     */
+    protected function getCol($image, $x, $y, $background)
+    {
+        $L = imagesx($image);
+        $H = imagesy($image);
+        if ($x < 0 || $x >= $L || $y < 0 || $y >= $H) {
+            return $background;
+        }
+
+        return imagecolorat($image, $x, $y);
+    }
+
+    /**
+     * @param $col
+     *
+     * @return array
+     */
+    protected function getRGB($col)
+    {
+        return array(
+            (int) ($col >> 16) & 0xff,
+            (int) ($col >> 8) & 0xff,
+            (int) ($col) & 0xff,
+        );
+    }
+
+    /**
+     * Validate the background image path. Return the image type if valid
+     *
+     * @param string $backgroundImage
+     * @return string
+     * @throws Exception
+     */
+    protected function validateBackgroundImage($backgroundImage)
+    {
+        // check if file exists
+        if (!file_exists($backgroundImage)) {
+            $backgroundImageExploded = explode('/', $backgroundImage);
+            $imageFileName = count($backgroundImageExploded) > 1? $backgroundImageExploded[count($backgroundImageExploded)-1] : $backgroundImage;
+
+            throw new Exception('Invalid background image: ' . $imageFileName);
+        }
+
+        // check image type
+        $finfo = finfo_open(FILEINFO_MIME_TYPE); // return mime type ala mimetype extension
+        $imageType = finfo_file($finfo, $backgroundImage);
+        finfo_close($finfo);
+
+        if (!in_array($imageType, $this->allowedBackgroundImageTypes)) {
+            throw new Exception('Invalid background image type! Allowed types are: ' . join(', ', $this->allowedBackgroundImageTypes));
+        }
+
+        return $imageType;
+    }
+
+    /**
+     * Create background image from type
+     *
+     * @param string $backgroundImage
+     * @param string $imageType
+     * @return resource
+     * @throws Exception
+     */
+    protected function createBackgroundImageFromType($backgroundImage, $imageType)
+    {
+        switch ($imageType) {
+            case 'image/jpeg':
+                $image = imagecreatefromjpeg($backgroundImage);
+                break;
+            case 'image/png':
+                $image = imagecreatefrompng($backgroundImage);
+                break;
+            case 'image/gif':
+                $image = imagecreatefromgif($backgroundImage);
+                break;
+
+            default:
+                throw new Exception('Not supported file type for background image!');
+                break;
+        }
+
+        return $image;
+    }
+}

libs/Captcha/CaptchaBuilderInterface.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace Gregwar\Captcha;
+
+/**
+ * A Captcha builder
+ */
+interface CaptchaBuilderInterface
+{
+    /**
+     * Builds the code
+     */
+    public function build($width, $height, $font, $fingerprint);
+
+    /**
+     * Saves the code to a file
+     */
+    public function save($filename, $quality);
+
+    /**
+     * Gets the image contents
+     */
+    public function get($quality);
+
+    /**
+     * Outputs the image
+     */
+    public function output($quality);
+}

libs/Captcha/ImageFileHandler.php

@@ -0,0 +1,105 @@
+<?php
+
+namespace Gregwar\Captcha;
+
+use Symfony\Component\Finder\Finder;
+
+/**
+ * Handles actions related to captcha image files including saving and garbage collection
+ *
+ * @author Gregwar <g.passault@gmail.com>
+ * @author Jeremy Livingston <jeremy@quizzle.com>
+ */
+class ImageFileHandler
+{
+    /**
+     * Name of folder for captcha images
+     * @var string
+     */
+    protected $imageFolder;
+
+    /**
+     * Absolute path to public web folder
+     * @var string
+     */
+    protected $webPath;
+
+    /**
+     * Frequency of garbage collection in fractions of 1
+     * @var int
+     */
+    protected $gcFreq;
+
+    /**
+     * Maximum age of images in minutes
+     * @var int
+     */
+    protected $expiration;
+
+    /**
+     * @param $imageFolder
+     * @param $webPath
+     * @param $gcFreq
+     * @param $expiration
+     */
+    public function __construct($imageFolder, $webPath, $gcFreq, $expiration)
+    {
+        $this->imageFolder      = $imageFolder;
+        $this->webPath          = $webPath;
+        $this->gcFreq           = $gcFreq;
+        $this->expiration       = $expiration;
+    }
+
+    /**
+     * Saves the provided image content as a file
+     *
+     * @param string $contents
+     *
+     * @return string
+     */
+    public function saveAsFile($contents)
+    {
+        $this->createFolderIfMissing();
+
+        $filename = md5(uniqid()) . '.jpg';
+        $filePath = $this->webPath . '/' . $this->imageFolder . '/' . $filename;
+        imagejpeg($contents, $filePath, 15);
+
+        return '/' . $this->imageFolder . '/' . $filename;
+    }
+
+    /**
+     * Randomly runs garbage collection on the image directory
+     *
+     * @return bool
+     */
+    public function collectGarbage()
+    {
+        if (!mt_rand(1, $this->gcFreq) == 1) {
+            return false;
+        }
+
+        $this->createFolderIfMissing();
+
+        $finder = new Finder();
+        $criteria = sprintf('<= now - %s minutes', $this->expiration);
+        $finder->in($this->webPath . '/' . $this->imageFolder)
+            ->date($criteria);
+
+        foreach ($finder->files() as $file) {
+            unlink($file->getPathname());
+        }
+
+        return true;
+    }
+
+    /**
+     * Creates the folder if it doesn't exist
+     */
+    protected function createFolderIfMissing()
+    {
+        if (!file_exists($this->webPath . '/' . $this->imageFolder)) {
+            mkdir($this->webPath . '/' . $this->imageFolder, 0755);
+        }
+    }
+}

libs/Captcha/LICENSE

@@ -0,0 +1,19 @@
+Copyright (c) <2012-2017> Grégoire Passault
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is furnished
+to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

libs/Captcha/PhraseBuilder.php

@@ -0,0 +1,75 @@
+<?php
+
+namespace Gregwar\Captcha;
+
+/**
+ * Generates random phrase
+ *
+ * @author Gregwar <g.passault@gmail.com>
+ */
+class PhraseBuilder implements PhraseBuilderInterface
+{
+    /**
+     * @var int
+     */
+    public $length;
+
+    /**
+     * @var string
+     */
+    public $charset;
+    /**
+     * Constructs a PhraseBuilder with given parameters
+     */
+    public function __construct($length = 5, $charset = 'abcdefghijklmnpqrstuvwxyz123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ')
+    {
+        $this->length = $length;
+        $this->charset = $charset;
+    }
+
+    /**
+     * Generates  random phrase of given length with given charset
+     */
+    public function build($length = null, $charset = null)
+    {
+        if ($length !== null) {
+            $this->length = $length;
+        }
+        if ($charset !== null) {
+            $this->charset = $charset;
+        }
+
+        $phrase = '';
+        $chars = str_split($this->charset);
+
+        for ($i = 0; $i < $this->length; $i++) {
+            $phrase .= $chars[array_rand($chars)];
+        }
+
+        return $phrase;
+    }
+
+    /**
+     * "Niceize" a code
+     */
+    public function niceize($str)
+    {
+        return self::doNiceize($str);
+    }
+    
+    /**
+     * A static helper to niceize
+     */
+    public static function doNiceize($str)
+    {
+        return strtr(strtolower($str), '01', 'ol');
+    }
+
+    /**
+     * A static helper to compare
+     */
+    public static function comparePhrases($str1, $str2)
+    {
+        return self::doNiceize($str1) === self::doNiceize($str2);
+    }
+}

libs/Captcha/PhraseBuilderInterface.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Gregwar\Captcha;
+
+/**
+ * Interface for the PhraseBuilder
+ *
+ * @author Gregwar <g.passault@gmail.com>
+ */
+interface PhraseBuilderInterface
+{
+    /**
+     * Generates  random phrase of given length with given charset
+     */
+    public function build();
+
+    /**
+     * "Niceize" a code
+     */
+    public function niceize($str);
+}