friendica-addons/libravatar/Services/Libravatar.php
Klaus Weidenbach b3a0ff0330 Libravatar Addon
Avatar addon to look up avatars at Libravatar. Libravatar is a free and open replacement for Gravatar and you can also host it on you own server. This addon only provides the lookup of avatars at Libravatar. It requires PHP >= 5.3 and you need to disable the gravatar addon.
2012-07-14 19:55:10 +02:00

373 lines
13 KiB
PHP

<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
/**
* PHP support for the Libravatar.org service.
*
* PHP version 5
*
* The MIT License
*
* Copyright (c) 2011 Services_Libravatar committers.
*
* 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.
*
* @category Services
* @package Services_Libravatar
* @author Melissa Draper <melissa@meldraweb.com>
* @copyright 2011 Services_Libravatar committers.
* @license http://www.opensource.org/licenses/mit-license.html MIT License
* @version SVN: <package_version>
* @link http://pear.php.net/package/Services_Libravatar
* @since File available since Release 0.1.0
*/
/**
* PHP support for the Libravatar.org service.
*
* Using this class is easy. After including or requiring
* PEAR/libravatar.php simply do:
* <code>
* $libravatar = new Services_Libravatar();
* $url = $libravatar->url('melissa@meldraweb.com');
* </code>
*
* This would populate $url with the string:
* http://cdn.libravatar.org/avatar/4db84629c121f2d443d33bdb9fd149bc
*
* A complicated lookup using all the options is:
* <code>
* $libravatar = new Services_Libravatar();
* $options = array();
* $options['s'] = '40';
* $options['algorithm'] = 'sha256';
* $options['https'] = true;
* $options['d'] = 'http://upload.wikimedia.org/wikipedia/commons/a/af/Tux.png';
* $url = $libravatar->url('melissa@meldraweb.com', $options);
* </code>
*
* @category Services
* @package Services_Libravatar
* @author Melissa Draper <melissa@meldraweb.com>
* @copyright 2011 Services_Libravatar committers.
* @license http://www.opensource.org/licenses/mit-license.html MIT License
* @version Release: <package_version>
* @link http://pear.php.net/package/Services_Libravatar
* @since Class available since Release 0.1.0
*/
class Services_Libravatar
{
/**
* Composes a URL for the identifier and options passed in
*
* Compose a full URL as specified by the Libravatar API, based on the
* email address or openid URL passed in, and the options specified.
*
* @param string $identifier a string of either an email address
* or an openid url
* @param array $options an array of (bool) https, (string) algorithm
* (string) s or size, (string) d or default
*
* @return string A string of a full URL for an avatar image
*
* @since Method available since Release 0.1.0
*/
public function url($identifier, $options = array())
{
// If no identifier has been passed, set it to a null.
// This way, there'll always be something returned.
if (!$identifier) {
$identifier = null;
}
$https = null;
if (isset($options['https']) && $options['https'] === true) {
$https = true;
}
// If the algorithm has been passed in $options, send it on.
// This will only affect email functionality.
if (isset($options['algorithm']) && is_string($options['algorithm'])) {
$identiferHash = $this->identiferHash(
$identifier,
$https,
$options['algorithm']
);
} else {
$identiferHash = $this->identiferHash($identifier, $https);
}
// Get the domain so we can determine the SRV stuff for federation
$domain = $this->domainGet($identifier, $https);
// If https has been specified in $options, make sure we make the
// correct SRV lookup
if (isset($options['https']) && $options['https'] === true) {
$service = $this->srvGet($domain, true);
$protocol = 'https';
} else {
$service = $this->srvGet($domain);
$protocol = 'http';
}
// We no longer need these, and they will pollute our query string
unset($options['algorithm']);
unset($options['https']);
// If there are any $options left, we want to make those into a query
$params = null;
if (count($options) > 0) {
$params = '?' . http_build_query($options);
}
// Compose the URL from the pieces we generated
$url = $protocol . '://' . $service . '/avatar/' . $identiferHash . $params;
// Return the URL string
return $url;
}
/**
* Create a hash of the identifier.
*
* Create a hash of the email address or openid passed in. Algorithm
* used for email address ONLY can be varied. Either md5 or sha256
* are supported by the Libravatar API. Will be ignored for openid.
*
* @param string $identifier A string of the email address or openid URL
* @param boolean $https If this is https, true.
* @param string $hash A string of the hash algorithm type to make
*
* @return string A string hash of the identifier.
*
* @since Method available since Release 0.1.0
*/
protected function identiferHash($identifier, $https = false, $hash = 'md5')
{
if (filter_var($identifier, FILTER_VALIDATE_EMAIL)) {
// If email, we can select our algorithm. Default to md5 for
// gravatar fallback.
return hash($hash, $identifier);
} else {
// The protocol is important. If we're lacking it this will not be
// filtered. Add it per our preference in the options.
if (stripos($identifier, 'http') !== 0) {
if ($https === true) {
$protocol = 'https://';
} else {
$protocol = 'http://';
}
$identifier = $protocol . $identifier;
}
// Is this an email address or an OpenID account
$filter = filter_var(
$identifier,
FILTER_VALIDATE_URL,
FILTER_FLAG_PATH_REQUIRED
);
if ($filter) {
// If this is an OpenID, split the string and make sure the
// formatting is correct. See the Libravatar API for more info.
// http://wiki.libravatar.org/api/
$url = parse_url($identifier);
$hashurl = strtolower($url['scheme']) . '://' .
strtolower($url['host']);
if (isset($url['port']) && $url['scheme'] === 'http'
&& $url['port'] != 80
|| isset($url['port']) && $url['scheme'] === 'https'
&& $url['port'] != 443
) {
$hashurl .= ':' . $url['port'];
}
$hashurl .= $url['path'];
return hash('sha256', $hashurl);
}
}
}
/**
* Grab the domain from the identifier.
*
* Extract the domain from the Email or OpenID.
*
* @param string $identifier A string of the email address or openid URL
* @param boolean $https If this is https, true.
*
* @return string A string of the domain to use
*
* @since Method available since Release 0.1.0
*/
protected function domainGet($identifier, $https = false)
{
// What are we, email or openid? Split ourself up and get the
// important bit out.
if (filter_var($identifier, FILTER_VALIDATE_EMAIL)) {
$email = explode('@', $identifier);
return $email[1];
} else {
// The protocol is important. If we're lacking it this will not be
// filtered. Add it per our preference in the options.
if ( ! strpos($identifier, 'http')) {
if ($https === true) {
$protocol = 'https://';
} else {
$protocol = 'http://';
}
$identifier = $protocol . $identifier;
}
$filter = filter_var(
$identifier,
FILTER_VALIDATE_URL,
FILTER_FLAG_PATH_REQUIRED
);
if ($filter) {
$url = parse_url($identifier);
$domain = $url['host'];
if (isset($url['port']) && $url['scheme'] === 'http'
&& $url['port'] != 80
|| isset($url['port']) && $url['scheme'] === 'https'
&& $url['port'] != 443
) {
$domain .= ':' . $url['port'];
}
return $domain;
}
}
}
/**
* Get the target to use.
*
* Get the SRV record, filtered by priority and weight. If our domain
* has no SRV records, fall back to Libravatar.org
*
* @param string $domain A string of the domain we extracted from the
* provided identifer with domainGet()
* @param boolean $https Whether or not to look for https records
*
* @return string The target URL.
*
* @since Method available since Release 0.1.0
*/
protected function srvGet($domain, $https = false)
{
// Are we going secure? Set up a fallback too.
if (isset($https) && $https === true) {
$subdomain = '_avatars-sec._tcp.';
$fallback = 'seccdn.';
} else {
$subdomain = '_avatars._tcp.';
$fallback = 'cdn.';
}
// Lets try get us some records based on the choice of subdomain
// and the domain we had passed in.
$srv = dns_get_record($subdomain . $domain, DNS_SRV);
// Did we get anything? No?
if (count($srv) == 0) {
// Then let's try Libravatar.org.
return $fallback . 'libravatar.org';
}
// Sort by the priority. We must get the lowest.
usort($srv, array($this, 'comparePriority'));
$top = $srv[0];
$sum = 0;
// Try to adhere to RFC2782's weighting algorithm, page 3
// "arrange all SRV RRs (that have not been ordered yet) in any order,
// except that all those with weight 0 are placed at the beginning of
// the list."
shuffle($srv);
$srvs = array();
foreach ($srv as $s) {
if ($s['weight'] == 0) {
array_unshift($srvs, $s);
} else {
array_push($srvs, $s);
}
}
foreach ($srvs as $s) {
if ($s['pri'] == $top['pri']) {
// "Compute the sum of the weights of those RRs"
$sum += (int) $s['weight'];
// "and with each RR associate the running sum in the selected
// order."
$pri[$sum] = $s;
}
}
// "Then choose a uniform random number between 0 and the sum computed
// (inclusive)"
$random = rand(0, $sum);
// "and select the RR whose running sum value is the first in the selected
// order which is greater than or equal to the random number selected"
foreach ($pri as $k => $v) {
if ($k >= $random) {
return $v['target'];
}
}
}
/**
* Sorting function for record priorities.
*
* @param mixed $a A mixed value passed by usort()
* @param mixed $b A mixed value passed by usort()
*
* @return mixed The result of the comparison
*
* @since Method available since Release 0.1.0
*/
protected function comparePriority($a, $b)
{
return $a['pri'] - $b['pri'];
}
}
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* c-hanging-comment-ender-p: nil
* End:
*/
?>