library/HTMLPurifier/AttrDef/CSS/Color.php

   1 <?php
   2
   3 /**
   4  * Validates Color as defined by CSS.
   5  */
   6 class HTMLPurifier_AttrDef_CSS_Color extends HTMLPurifier_AttrDef
   7 {
   8
   9     /**
  10      * @type HTMLPurifier_AttrDef_CSS_AlphaValue
  11      */
  12     protected $alpha;
  13
  14     public function __construct()
  15     {
  16         $this->alpha = new HTMLPurifier_AttrDef_CSS_AlphaValue();
  17     }
  18
  19     /**
  20      * @param string $color
  21      * @param HTMLPurifier_Config $config
  22      * @param HTMLPurifier_Context $context
  23      * @return bool|string
  24      */
  25     public function validate($color, $config, $context)
  26     {
  27         static $colors = null;
  28         if ($colors === null) {
  29             $colors = $config->get('Core.ColorKeywords');
  30         }
  31
  32         $color = trim($color);
  33         if ($color === '') {
  34             return false;
  35         }
  36
  37         $lower = strtolower($color);
  38         if (isset($colors[$lower])) {
  39             return $colors[$lower];
  40         }
  41
  42         if (preg_match('#(rgb|rgba|hsl|hsla)\(#', $color, $matches) === 1) {
  43             $length = strlen($color);
  44             if (strpos($color, ')') !== $length - 1) {
  45                 return false;
  46             }
  47
  48             // get used function : rgb, rgba, hsl or hsla
  49             $function = $matches[1];
  50
  51             $parameters_size = 3;
  52             $alpha_channel = false;
  53             if (substr($function, -1) === 'a') {
  54                 $parameters_size = 4;
  55                 $alpha_channel = true;
  56             }
  57
  58             /*
  59              * Allowed types for values :
  60              * parameter_position => [type => max_value]
  61              */
  62             $allowed_types = array(
  63                 1 => array('percentage' => 100, 'integer' => 255),
  64                 2 => array('percentage' => 100, 'integer' => 255),
  65                 3 => array('percentage' => 100, 'integer' => 255),
  66             );
  67             $allow_different_types = false;
  68
  69             if (strpos($function, 'hsl') !== false) {
  70                 $allowed_types = array(
  71                     1 => array('integer' => 360),
  72                     2 => array('percentage' => 100),
  73                     3 => array('percentage' => 100),
  74                 );
  75                 $allow_different_types = true;
  76             }
  77
  78             $values = trim(str_replace($function, '', $color), ' ()');
  79
  80             $parts = explode(',', $values);
  81             if (count($parts) !== $parameters_size) {
  82                 return false;
  83             }
  84
  85             $type = false;
  86             $new_parts = array();
  87             $i = 0;
  88
  89             foreach ($parts as $part) {
  90                 $i++;
  91                 $part = trim($part);
  92
  93                 if ($part === '') {
  94                     return false;
  95                 }
  96
  97                 // different check for alpha channel
  98                 if ($alpha_channel === true && $i === count($parts)) {
  99                     $result = $this->alpha->validate($part, $config, $context);
 100
 101                     if ($result === false) {
 102                         return false;
 103                     }
 104
 105                     $new_parts[] = (string)$result;
 106                     continue;
 107                 }
 108
 109                 if (substr($part, -1) === '%') {
 110                     $current_type = 'percentage';
 111                 } else {
 112                     $current_type = 'integer';
 113                 }
 114
 115                 if (!array_key_exists($current_type, $allowed_types[$i])) {
 116                     return false;
 117                 }
 118
 119                 if (!$type) {
 120                     $type = $current_type;
 121                 }
 122
 123                 if ($allow_different_types === false && $type != $current_type) {
 124                     return false;
 125                 }
 126
 127                 $max_value = $allowed_types[$i][$current_type];
 128
 129                 if ($current_type == 'integer') {
 130                     // Return value between range 0 -> $max_value
 131                     $new_parts[] = (int)max(min($part, $max_value), 0);
 132                 } elseif ($current_type == 'percentage') {
 133                     $new_parts[] = (float)max(min(rtrim($part, '%'), $max_value), 0) . '%';
 134                 }
 135             }
 136
 137             $new_values = implode(',', $new_parts);
 138
 139             $color = $function . '(' . $new_values . ')';
 140         } else {
 141             // hexadecimal handling
 142             if ($color[0] === '#') {
 143                 $hex = substr($color, 1);
 144             } else {
 145                 $hex = $color;
 146                 $color = '#' . $color;
 147             }
 148             $length = strlen($hex);
 149             if ($length !== 3 && $length !== 6) {
 150                 return false;
 151             }
 152             if (!ctype_xdigit($hex)) {
 153                 return false;
 154             }
 155         }
 156         return $color;
 157     }
 158
 159 }
 160
 161 // vim: et sw=4 sts=4