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Diffstat (limited to 'library/HTMLPurifier/AttrDef/CSS/FontFamily.php')
| -rw-r--r-- | library/HTMLPurifier/AttrDef/CSS/FontFamily.php | 219 |
1 files changed, 0 insertions, 219 deletions
diff --git a/library/HTMLPurifier/AttrDef/CSS/FontFamily.php b/library/HTMLPurifier/AttrDef/CSS/FontFamily.php deleted file mode 100644 index 74e24c881..000000000 --- a/library/HTMLPurifier/AttrDef/CSS/FontFamily.php +++ /dev/null @@ -1,219 +0,0 @@ -<?php - -/** - * Validates a font family list according to CSS spec - */ -class HTMLPurifier_AttrDef_CSS_FontFamily extends HTMLPurifier_AttrDef -{ - - protected $mask = null; - - public function __construct() - { - $this->mask = '_- '; - for ($c = 'a'; $c <= 'z'; $c++) { - $this->mask .= $c; - } - for ($c = 'A'; $c <= 'Z'; $c++) { - $this->mask .= $c; - } - for ($c = '0'; $c <= '9'; $c++) { - $this->mask .= $c; - } // cast-y, but should be fine - // special bytes used by UTF-8 - for ($i = 0x80; $i <= 0xFF; $i++) { - // We don't bother excluding invalid bytes in this range, - // because the our restriction of well-formed UTF-8 will - // prevent these from ever occurring. - $this->mask .= chr($i); - } - - /* - PHP's internal strcspn implementation is - O(length of string * length of mask), making it inefficient - for large masks. However, it's still faster than - preg_match 8) - for (p = s1;;) { - spanp = s2; - do { - if (*spanp == c || p == s1_end) { - return p - s1; - } - } while (spanp++ < (s2_end - 1)); - c = *++p; - } - */ - // possible optimization: invert the mask. - } - - /** - * @param string $string - * @param HTMLPurifier_Config $config - * @param HTMLPurifier_Context $context - * @return bool|string - */ - public function validate($string, $config, $context) - { - static $generic_names = array( - 'serif' => true, - 'sans-serif' => true, - 'monospace' => true, - 'fantasy' => true, - 'cursive' => true - ); - $allowed_fonts = $config->get('CSS.AllowedFonts'); - - // assume that no font names contain commas in them - $fonts = explode(',', $string); - $final = ''; - foreach ($fonts as $font) { - $font = trim($font); - if ($font === '') { - continue; - } - // match a generic name - if (isset($generic_names[$font])) { - if ($allowed_fonts === null || isset($allowed_fonts[$font])) { - $final .= $font . ', '; - } - continue; - } - // match a quoted name - if ($font[0] === '"' || $font[0] === "'") { - $length = strlen($font); - if ($length <= 2) { - continue; - } - $quote = $font[0]; - if ($font[$length - 1] !== $quote) { - continue; - } - $font = substr($font, 1, $length - 2); - } - - $font = $this->expandCSSEscape($font); - - // $font is a pure representation of the font name - - if ($allowed_fonts !== null && !isset($allowed_fonts[$font])) { - continue; - } - - if (ctype_alnum($font) && $font !== '') { - // very simple font, allow it in unharmed - $final .= $font . ', '; - continue; - } - - // bugger out on whitespace. form feed (0C) really - // shouldn't show up regardless - $font = str_replace(array("\n", "\t", "\r", "\x0C"), ' ', $font); - - // Here, there are various classes of characters which need - // to be treated differently: - // - Alphanumeric characters are essentially safe. We - // handled these above. - // - Spaces require quoting, though most parsers will do - // the right thing if there aren't any characters that - // can be misinterpreted - // - Dashes rarely occur, but they fairly unproblematic - // for parsing/rendering purposes. - // The above characters cover the majority of Western font - // names. - // - Arbitrary Unicode characters not in ASCII. Because - // most parsers give little thought to Unicode, treatment - // of these codepoints is basically uniform, even for - // punctuation-like codepoints. These characters can - // show up in non-Western pages and are supported by most - // major browsers, for example: "ＭＳ 明朝" is a - // legitimate font-name - // <http://ja.wikipedia.org/wiki/MS_明朝>. See - // the CSS3 spec for more examples: - // <http://www.w3.org/TR/2011/WD-css3-fonts-20110324/localizedfamilynames.png> - // You can see live samples of these on the Internet: - // <http://www.google.co.jp/search?q=font-family+ＭＳ+明朝|ゴシック> - // However, most of these fonts have ASCII equivalents: - // for example, 'MS Mincho', and it's considered - // professional to use ASCII font names instead of - // Unicode font names. Thanks Takeshi Terada for - // providing this information. - // The following characters, to my knowledge, have not been - // used to name font names. - // - Single quote. While theoretically you might find a - // font name that has a single quote in its name (serving - // as an apostrophe, e.g. Dave's Scribble), I haven't - // been able to find any actual examples of this. - // Internet Explorer's cssText translation (which I - // believe is invoked by innerHTML) normalizes any - // quoting to single quotes, and fails to escape single - // quotes. (Note that this is not IE's behavior for all - // CSS properties, just some sort of special casing for - // font-family). So a single quote *cannot* be used - // safely in the font-family context if there will be an - // innerHTML/cssText translation. Note that Firefox 3.x - // does this too. - // - Double quote. In IE, these get normalized to - // single-quotes, no matter what the encoding. (Fun - // fact, in IE8, the 'content' CSS property gained - // support, where they special cased to preserve encoded - // double quotes, but still translate unadorned double - // quotes into single quotes.) So, because their - // fixpoint behavior is identical to single quotes, they - // cannot be allowed either. Firefox 3.x displays - // single-quote style behavior. - // - Backslashes are reduced by one (so \\ -> \) every - // iteration, so they cannot be used safely. This shows - // up in IE7, IE8 and FF3 - // - Semicolons, commas and backticks are handled properly. - // - The rest of the ASCII punctuation is handled properly. - // We haven't checked what browsers do to unadorned - // versions, but this is not important as long as the - // browser doesn't /remove/ surrounding quotes (as IE does - // for HTML). - // - // With these results in hand, we conclude that there are - // various levels of safety: - // - Paranoid: alphanumeric, spaces and dashes(?) - // - International: Paranoid + non-ASCII Unicode - // - Edgy: Everything except quotes, backslashes - // - NoJS: Standards compliance, e.g. sod IE. Note that - // with some judicious character escaping (since certain - // types of escaping doesn't work) this is theoretically - // OK as long as innerHTML/cssText is not called. - // We believe that international is a reasonable default - // (that we will implement now), and once we do more - // extensive research, we may feel comfortable with dropping - // it down to edgy. - - // Edgy: alphanumeric, spaces, dashes, underscores and Unicode. Use of - // str(c)spn assumes that the string was already well formed - // Unicode (which of course it is). - if (strspn($font, $this->mask) !== strlen($font)) { - continue; - } - - // Historical: - // In the absence of innerHTML/cssText, these ugly - // transforms don't pose a security risk (as \\ and \" - // might--these escapes are not supported by most browsers). - // We could try to be clever and use single-quote wrapping - // when there is a double quote present, but I have choosen - // not to implement that. (NOTE: you can reduce the amount - // of escapes by one depending on what quoting style you use) - // $font = str_replace('\\', '\\5C ', $font); - // $font = str_replace('"', '\\22 ', $font); - // $font = str_replace("'", '\\27 ', $font); - - // font possibly with spaces, requires quoting - $final .= "'$font', "; - } - $final = rtrim($final, ', '); - if ($final === '') { - return false; - } - return $final; - } - -} - -// vim: et sw=4 sts=4 |