--- /dev/null
+<?php
+
+/**
+ * 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 <![CDATA[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 <![CDATA[blocks.
+ *
+ * PHP versions 4 and 5
+ *
+ * LICENSE: See the COPYING file included in this distribution.
+ *
+ * @access private
+ * @package OpenID
+ * @author JanRain, Inc. <openid@janrain.com>
+ * @copyright 2005-2008 Janrain, Inc.
+ * @license http://www.apache.org/licenses/LICENSE-2.0 Apache
+ */
+
+/**
+ * Require Auth_OpenID::arrayGet().
+ */
+require_once "Auth/OpenID.php";
+
+class Auth_OpenID_Parse {
+
+ /**
+ * Specify some flags for use with regex matching.
+ */
+ var $_re_flags = "si";
+
+ /**
+ * Stuff to remove before we start looking for tags
+ */
+ var $_removed_re =
+ "<!--.*?-->|<!\[CDATA\[.*?\]\]>|<script\b(?!:)[^>]*>.*?<\/script>";
+
+ /**
+ * Starts with the tag name at a word boundary, where the tag name
+ * is not a namespace
+ */
+ var $_tag_expr = "<%s\b(?!:)([^>]*?)(?:\/>|>(.*?)(?:<\/?%s\s*>|\Z))";
+
+ var $_attr_find = '\b(\w+)=("[^"]*"|\'[^\']*\'|[^\'"\s\/<>]+)';
+
+ var $_open_tag_expr = "<%s\b";
+ var $_close_tag_expr = "<((\/%s\b)|(%s[^>\/]*\/))>";
+
+ function Auth_OpenID_Parse()
+ {
+ $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("|",
+ $this->_entity_replacements));
+ }
+
+ /**
+ * Returns a regular expression that will match a given tag in an
+ * SGML string.
+ */
+ function tagMatcher($tag_name, $close_tags = null)
+ {
+ $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, $this->_re_flags);
+ }
+
+ function openTag($tag_name)
+ {
+ $expr = sprintf($this->_open_tag_expr, $tag_name);
+ return sprintf("/%s/%s", $expr, $this->_re_flags);
+ }
+
+ function closeTag($tag_name)
+ {
+ $expr = sprintf($this->_close_tag_expr, $tag_name, $tag_name);
+ return sprintf("/%s/%s", $expr, $this->_re_flags);
+ }
+
+ function htmlBegin($s)
+ {
+ $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 $matches[0][1];
+ }
+
+ function htmlEnd($s)
+ {
+ $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];
+ }
+
+ function headFind()
+ {
+ return $this->tagMatcher('head', array('body', 'html'));
+ }
+
+ function replaceEntities($str)
+ {
+ foreach ($this->_entity_replacements as $old => $new) {
+ $str = preg_replace(sprintf("/&%s;/", $old), $new, $str);
+ }
+ return $str;
+ }
+
+ function removeQuotes($str)
+ {
+ $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;
+ }
+ }
+
+ /**
+ * Find all link tags in a string representing a HTML document and
+ * return a list of their attributes.
+ *
+ * @param string $html The text to parse
+ * @return array $list An array of arrays of attributes, one for each
+ * link tag
+ */
+ function parseLinkAttrs($html)
+ {
+ $stripped = preg_replace($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);
+
+ // Try to find the <HEAD> tag.
+ $head_re = $this->headFind();
+ $head_matches = array();
+ if (!preg_match($head_re, $stripped, $head_matches)) {
+ return array();
+ }
+
+ $link_data = array();
+ $link_matches = array();
+
+ if (!preg_match_all($this->_link_find, $head_matches[0],
+ $link_matches)) {
+ return array();
+ }
+
+ foreach ($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;
+ }
+
+ return $link_data;
+ }
+
+ function relMatches($rel_attr, $target_rel)
+ {
+ // 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 == $target_rel) {
+ return 1;
+ }
+ }
+
+ return 0;
+ }
+
+ function linkHasRel($link_attrs, $target_rel)
+ {
+ // 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,
+ $target_rel));
+ }
+
+ function findLinksRel($link_attrs_list, $target_rel)
+ {
+ // 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 $result;
+ }
+
+ function findFirstHref($link_attrs_list, $target_rel)
+ {
+ // 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);
+ }
+}
+
+function Auth_OpenID_legacy_discover($html_text, $server_rel,
+ $delegate_rel)
+{
+ $p = new Auth_OpenID_Parse();
+
+ $link_attrs = $p->parseLinkAttrs($html_text);
+
+ $server_url = $p->findFirstHref($link_attrs,
+ $server_rel);
+
+ if ($server_url === null) {
+ return false;
+ } else {
+ $delegate_url = $p->findFirstHref($link_attrs,
+ $delegate_rel);
+ return array($delegate_url, $server_url);
+ }
+}
+
+?>
\ No newline at end of file
projects / quix0rs-gnu-social.git / blobdiff