This module implements a VERY limited parser that finds <link> tags in the head of HTML or XHTML documents and parses out their attributes according to the OpenID spec. More...

Collaboration diagram for Auth_OpenID_Parse:

Public Member Functions
	Auth_OpenID_Parse ()

	tagMatcher ($tag_name, $close_tags=null)
	Returns a regular expression that will match a given tag in an SGML string. More...

	openTag ($tag_name)

	closeTag ($tag_name)

	htmlBegin ($s)

	htmlEnd ($s)

	headFind ()

	replaceEntities ($str)

	removeQuotes ($str)

	match ($regexp, $text, &$match)

	parseLinkAttrs ($html)
	Find all link tags in a string representing a HTML document and return a list of their attributes. More...

	relMatches ($rel_attr, $target_rel)

	linkHasRel ($link_attrs, $target_rel)

	findLinksRel ($link_attrs_list, $target_rel)

	findFirstHref ($link_attrs_list, $target_rel)

Data Fields
	$_re_flags = "si"
	Specify some flags for use with regex matching. More...

	$_removed_re
	Stuff to remove before we start looking for tags. More...

	$_tag_expr = "<%s\b(?!:)([^>]?)(?:\/>\|>(.)(?:<\/?%s\s*>\|\Z))"
	Starts with the tag name at a word boundary, where the tag name is not a namespace. More...

	$_attr_find = '\b(\w+)=("[^"]"\|\'[^\']\'\|[^\'"\s\/<>]+)'

	$_open_tag_expr = "<%s\b"

	$_close_tag_expr = "<((\/%s\b)\|(%s[^>\/]*\/))>"

Detailed Description

This module implements a VERY limited parser that finds <link> tags in the head of HTML or XHTML documents and parses out their attributes according to the OpenID spec.

It is a liberal parser, but it requires these things from the data in order to work:

There must be an open <html> tag
There must be an open <head> tag inside of the <html> tag
Only <link>s that are found inside of the <head> tag are parsed (this is by design)
The parser follows the OpenID specification in resolving the attributes of the link tags. This means that the attributes DO NOT get resolved as they would by an XML or HTML parser. In particular, only certain entities get replaced, and href attributes do not get resolved relative to a base URL.

From http://openid.net/specs.bml:

The openid.server URL MUST be an absolute URL. OpenID consumers MUST NOT attempt to resolve relative URLs.
The openid.server URL MUST NOT include entities other than &, <, >, and ".

The parser ignores SGML comments and blocks. Both kinds of quoting are allowed for attributes.

The parser deals with invalid markup in these ways:

Tag names are not case-sensitive
The <html> tag is accepted even when it is not at the top level
The <head> tag is accepted even when it is not a direct child of the <html> tag, but a <html> tag must be an ancestor of the <head> tag
<link> tags are accepted even when they are not direct children of the <head> tag, but a <head> tag must be an ancestor of the <link> tag
If there is no closing tag for an open <html> or <head> tag, the remainder of the document is viewed as being inside of the tag. If there is no closing tag for a <link> tag, the link tag is treated as a short tag. Exceptions to this rule are that <html> closes <html> and <body> or <head> closes <head>
Attributes of the <link> tag are not required to be quoted.
In the case of duplicated attribute names, the attribute coming last in the tag will be the value returned.
Any text that does not parse as an attribute within a link tag will be ignored. (e.g. <link pumpkin rel='openid.server' > will ignore pumpkin)
If there are more than one <html> or <head> tag, the parser only looks inside of the first one.
The contents of <script> tags are ignored entirely, except unclosed <script> tags. Unclosed <script> tags are ignored.
Any other invalid markup is ignored, including unclosed SGML comments and unclosed blocks.

PHP versions 4 and 5

LICENSE: See the COPYING file included in this distribution.

@access private @package OpenID

Author: JanRain, Inc. <openi.nosp@m.d@ja.nosp@m.nrain.nosp@m..com>

Copyright: 2005-2008 Janrain, Inc. @license http://www.apache.org/licenses/LICENSE-2.0 Apache Require Auth_OpenID::arrayGet().

Definition at line 87 of file Parse.php.

Member Function Documentation

◆ Auth_OpenID_Parse()

Auth_OpenID_Parse::Auth_OpenID_Parse ( )

Definition at line 111 of file Parse.php.

    {
        $this->_link_find = sprintf("/<link\b(?!:)([^>]*)(?!<)>/%s",
                                    $this->_re_flags);
 
        $this->_entity_replacements = array(
                                            'amp' => '&',
                                            'lt' => '<',
                                            'gt' => '>',
                                            'quot' => '"'
                                            );
 
        $this->_attr_find = sprintf("/%s/%s",
                                    $this->_attr_find,
                                    $this->_re_flags);
 
        $this->_removed_re = sprintf("/%s/%s",
                                     $this->_removed_re,
                                     $this->_re_flags);
 
        $this->_ent_replace =
            sprintf("&(%s);", implode("|",
                                      $this->_entity_replacements));
    }

◆ closeTag()

Auth_OpenID_Parse::closeTag ( $tag_name )

Definition at line 161 of file Parse.php.

    {
        $expr = sprintf($this->_close_tag_expr, $tag_name, $tag_name);
        return sprintf("/%s/%s", $expr, $this->_re_flags);
    }

Referenced by htmlEnd().

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◆ findFirstHref()

Auth_OpenID_Parse::findFirstHref	(	$link_attrs_list,
		$target_rel
	)

Definition at line 344 of file Parse.php.

    {
        // Return the value of the href attribute for the first link
        // tag in the list that has target_rel as a relationship.
        // XXX: TESTME
        $matches = $this->findLinksRel($link_attrs_list,
                                       $target_rel);
        if (!$matches) {
            return null;
        }
        $first = $matches[0];
        return Auth_OpenID::arrayGet($first, 'href', null);
    }

References Auth_OpenID\arrayGet(), and findLinksRel().

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◆ findLinksRel()

Auth_OpenID_Parse::findLinksRel	(	$link_attrs_list,
		$target_rel
	)

Definition at line 329 of file Parse.php.

    {
        // Filter the list of link attributes on whether it has
        // target_rel as a relationship.
        // XXX: TESTME
        $result = array();
        foreach ($link_attrs_list as $attr) {
            if ($this->linkHasRel($attr, $target_rel)) {
                $result[] = $attr;
            }
        }
 
        return $result;
    }

References $result, and linkHasRel().

Referenced by findFirstHref().

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◆ headFind()

Auth_OpenID_Parse::headFind ( )

Definition at line 191 of file Parse.php.

    {
        return $this->tagMatcher('head', array('body', 'html'));
    }

References tagMatcher().

Referenced by parseLinkAttrs().

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◆ htmlBegin()

Auth_OpenID_Parse::htmlBegin ( $s )

Definition at line 167 of file Parse.php.

    {
        $matches = array();
        $result = preg_match($this->openTag('html'), $s,
                             $matches, PREG_OFFSET_CAPTURE);
        if ($result === false || !$matches) {
            return false;
        }
        // Return the offset of the first match.
        return $matches[0][1];
    }

References $result, and openTag().

Referenced by parseLinkAttrs().

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◆ htmlEnd()

Auth_OpenID_Parse::htmlEnd ( $s )

Definition at line 179 of file Parse.php.

    {
        $matches = array();
        $result = preg_match($this->closeTag('html'), $s,
                             $matches, PREG_OFFSET_CAPTURE);
        if ($result === false || !$matches) {
            return false;
        }
        // Return the offset of the first match.
        return $matches[count($matches) - 1][1];
    }

References $result, and closeTag().

Referenced by parseLinkAttrs().

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◆ linkHasRel()

Auth_OpenID_Parse::linkHasRel	(	$link_attrs,
		$target_rel
	)

Definition at line 320 of file Parse.php.

    {
        // Does this link have target_rel as a relationship?
        // XXX: TESTME
        $rel_attr = Auth_OpeniD::arrayGet($link_attrs, 'rel', null);
        return ($rel_attr && $this->relMatches($rel_attr,
                                               $target_rel));
    }

References relMatches().

Referenced by findLinksRel().

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◆ match()

Auth_OpenID_Parse::match	(		$regexp,
			$text,
		&	$match
	)

Definition at line 219 of file Parse.php.

    {
        if (!is_callable('mb_ereg_search_init')) {
            return preg_match($regexp, $text, $match);
        }
 
        $regexp = substr($regexp, 1, strlen($regexp) - 2 - strlen($this->_re_flags));
        mb_ereg_search_init($text);
        if (!mb_ereg_search($regexp)) {
            return false;
        }
        list($match) = mb_ereg_search_getregs();
        return true;
    }

References $text.

Referenced by parseLinkAttrs().

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◆ openTag()

Auth_OpenID_Parse::openTag ( $tag_name )

Definition at line 155 of file Parse.php.

    {
        $expr = sprintf($this->_open_tag_expr, $tag_name);
        return sprintf("/%s/%s", $expr, $this->_re_flags);
    }

Referenced by htmlBegin().

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◆ parseLinkAttrs()

Auth_OpenID_Parse::parseLinkAttrs ( $html )

Find all link tags in a string representing a HTML document and return a list of their attributes.

Todo:: This is quite ineffective and may fail with the default pcre.backtrack_limit of 100000 in PHP 5.2, if $html is big. It should rather use stripos (in PHP5) or strpos()+strtoupper() in PHP4 to manage this.

Parameters

string $html The text to parse

Returns: array $list An array of arrays of attributes, one for each link tag

Definition at line 247 of file Parse.php.

    {
        $stripped = preg_replace($this->_removed_re,
                                 "",
                                 $html);
 
        $html_begin = $this->htmlBegin($stripped);
        $html_end = $this->htmlEnd($stripped);
 
        if ($html_begin === false) {
            return array();
        }
 
        if ($html_end === false) {
            $html_end = strlen($stripped);
        }
 
        $stripped = substr($stripped, $html_begin,
                           $html_end - $html_begin);
 
        // Workaround to prevent PREG_BACKTRACK_LIMIT_ERROR:
        $old_btlimit = ini_set( 'pcre.backtrack_limit', -1 );
 
        // Try to find the <HEAD> tag.
        $head_re = $this->headFind();
        $head_match = '';
        if (!$this->match($head_re, $stripped, $head_match)) {
                     ini_set( 'pcre.backtrack_limit', $old_btlimit );
                     return array();
        }
 
        $link_data = array();
        $link_matches = array();
 
        if (!preg_match_all($this->_link_find, $head_match,
                            $link_matches)) {
            ini_set( 'pcre.backtrack_limit', $old_btlimit );
            return array();
        }
 
        foreach ($link_matches[0] as $link) {
            $attr_matches = array();
            preg_match_all($this->_attr_find, $link, $attr_matches);
            $link_attrs = array();
            foreach ($attr_matches[0] as $index => $full_match) {
                $name = $attr_matches[1][$index];
                $value = $this->replaceEntities(
                              $this->removeQuotes($attr_matches[2][$index]));
 
                $link_attrs[strtolower($name)] = $value;
            }
            $link_data[] = $link_attrs;
        }
 
        ini_set( 'pcre.backtrack_limit', $old_btlimit );
        return $link_data;
    }

References $html, headFind(), htmlBegin(), htmlEnd(), match(), removeQuotes(), and replaceEntities().

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◆ relMatches()

Auth_OpenID_Parse::relMatches	(	$rel_attr,
		$target_rel
	)

Definition at line 305 of file Parse.php.

    {
        // Does this target_rel appear in the rel_str?
        // XXX: TESTME
        $rels = preg_split("/\s+/", trim($rel_attr));
        foreach ($rels as $rel) {
            $rel = strtolower($rel);
            if ($rel == $target_rel) {
                return 1;
            }
        }
 
        return 0;
    }

Referenced by linkHasRel().

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◆ removeQuotes()

Auth_OpenID_Parse::removeQuotes ( $str )

Definition at line 204 of file Parse.php.

    {
        $matches = array();
        $double = '/^"(.*)"$/';
        $single = "/^\'(.*)\'$/";
 
        if (preg_match($double, $str, $matches)) {
            return $matches[1];
        } else if (preg_match($single, $str, $matches)) {
            return $matches[1];
        } else {
            return $str;
        }
    }

Referenced by parseLinkAttrs().

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◆ replaceEntities()

Auth_OpenID_Parse::replaceEntities ( $str )

Definition at line 196 of file Parse.php.

    {
        foreach ($this->_entity_replacements as $old => $new) {
            $str = preg_replace(sprintf("/&%s;/", $old), $new, $str);
        }
        return $str;
    }

Referenced by parseLinkAttrs().

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◆ tagMatcher()

Auth_OpenID_Parse::tagMatcher	(	$tag_name,
		$close_tags = `null`
	)

Returns a regular expression that will match a given tag in an SGML string.

Definition at line 140 of file Parse.php.

    {
        $expr = $this->_tag_expr;
 
        if ($close_tags) {
            $options = implode("|", array_merge(array($tag_name), $close_tags));
            $closer = sprintf("(?:%s)", $options);
        } else {
            $closer = $tag_name;
        }
 
        $expr = sprintf($expr, $tag_name, $closer);
        return sprintf("/%s/%s", $expr, $this->_re_flags);
    }

References $_tag_expr, and $options.

Referenced by headFind().

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Field Documentation

◆ $_attr_find

Auth_OpenID_Parse::$_attr_find = '\b(\w+)=("[^"]*"|\'[^\']*\'|[^\'"\s\/<>]+)'

Definition at line 106 of file Parse.php.

◆ $_close_tag_expr

Auth_OpenID_Parse::$_close_tag_expr = "<((\/%s\b)|(%s[^>\/]*\/))>"

Definition at line 109 of file Parse.php.

◆ $_open_tag_expr

Auth_OpenID_Parse::$_open_tag_expr = "<%s\b"

Definition at line 108 of file Parse.php.

◆ $_re_flags

Auth_OpenID_Parse::$_re_flags = "si"

Specify some flags for use with regex matching.

Definition at line 92 of file Parse.php.

◆ $_removed_re

Auth_OpenID_Parse::$_removed_re

Initial value:

=

"|<!\[CDATA\[.*?\]\]>|<script\b(?!:)[^>]*>.*?<\/script>"

Stuff to remove before we start looking for tags.

Definition at line 97 of file Parse.php.

◆ $_tag_expr

Auth_OpenID_Parse::$_tag_expr = "<%s\b(?!:)([^>]*?)(?:\/>|>(.*)(?:<\/?%s\s*>|\Z))"

Starts with the tag name at a word boundary, where the tag name is not a namespace.

Definition at line 104 of file Parse.php.

Referenced by tagMatcher().

The documentation for this class was generated from the following file:

Services/OpenId/lib/Auth/OpenID/Parse.php

Public Member Functions

Data Fields

Detailed Description

Member Function Documentation

◆ Auth_OpenID_Parse()

◆ closeTag()

◆ findFirstHref()

◆ findLinksRel()

◆ headFind()

◆ htmlBegin()

◆ htmlEnd()

◆ linkHasRel()

◆ match()

◆ openTag()

◆ parseLinkAttrs()

◆ relMatches()

◆ removeQuotes()

◆ replaceEntities()

◆ tagMatcher()

Field Documentation

◆ $_attr_find

◆ $_close_tag_expr

◆ $_open_tag_expr

◆ $_re_flags

◆ $_removed_re

◆ $_tag_expr