streams/include/network.php

<?php

use Zotlabs\Lib\Libzot;
use Zotlabs\Lib\Zotfinger;
use Zotlabs\Lib\Webfinger;
use Zotlabs\Lib\ActivityStreams;
use Zotlabs\Lib\Activity;
use Zotlabs\Lib\ActivityPub;
use Zotlabs\Lib\Queue;
use Zotlabs\Lib\System;
use Zotlabs\Lib\Keyutils;
use Zotlabs\Lib\LDSignatures;
use Zotlabs\Web\HTTPSig;
use Zotlabs\Daemon\Run;


/**
 * @file include/network.php
 * @brief Network related functions.
 */

/**
 * @brief Returns path to CA file.
 *
 * @return string
 */
function get_capath() {
	return appdirpath() . '/library/cacert.pem';
}

/**
 * @brief fetches an URL.
 *
 * @param string $url
 *    URL to fetch
 * @param boolean $binary default false
 *    TRUE if asked to return binary results (file download)
 * @param int $redirects default 0
 *    internal use, recursion counter
 * @param array $opts (optional parameters) associative array with:
 *  * \b timeout => int seconds, default system config value or 60 seconds
 *  * \b headers => array of additional header fields
 *  * \b http_auth => username:password
 *  * \b novalidate => do not validate SSL certs, default is to validate using our CA list
 *  * \b nobody => only return the header
 *  * \b filep => stream resource to write body to. header and body are not returned when using this option.
 *  * \b custom => custom request method: e.g. 'PUT', 'DELETE'
 *  * \b cookiejar => cookie file (write)
 *  * \b cookiefile => cookie file (read)
 *  * \b session => boolean; append session cookie *if* $url is our own site
 *
 * @return array an associative array with:
 *  * \e int \b return_code => HTTP return code or 0 if timeout or failure
 *  * \e boolean \b success => boolean true (if HTTP 2xx result) or false
 *  * \e string \b header => HTTP headers
 *  * \e string \b body => fetched content
 */
function z_fetch_url($url, $binary = false, $redirects = 0, $opts = []) {

	$ret = array('return_code' => 0, 'success' => false, 'header' => "", 'body' => "");
	$passthru = false;

	$ch = @curl_init($url);
	if(($redirects > 8) || (! $ch))
		return $ret;

	if(! array_key_exists('request_target',$opts)) {
		$opts['request_target'] = 'get ' . get_request_string($url);
	}


	@curl_setopt($ch, CURLOPT_HEADER, true);
	@curl_setopt($ch, CURLINFO_HEADER_OUT, true);
	@curl_setopt($ch, CURLOPT_CAINFO, get_capath());
	@curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
	@curl_setopt($ch, CURLOPT_RETURNTRANSFER,true);
	@curl_setopt($ch, CURLOPT_ENCODING, '');
	
	$ciphers = @get_config('system','curl_ssl_ciphers');
	if($ciphers)
		@curl_setopt($ch, CURLOPT_SSL_CIPHER_LIST, $ciphers);

	if(x($opts,'filep')) {
		@curl_setopt($ch, CURLOPT_FILE, $opts['filep']);
		@curl_setopt($ch, CURLOPT_HEADER, false);
		@curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
		$passthru = true;
	}

	if (x($opts['useragent'])) {
		@curl_setopt($ch, CURLOPT_USERAGENT, $opts['useragent']);
	}
	else {
		@curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (compatible; zot)");
	}

	if(x($opts,'upload'))
		@curl_setopt($ch, CURLOPT_UPLOAD, $opts['upload']);

	if(x($opts,'infile'))
		@curl_setopt($ch, CURLOPT_INFILE, $opts['infile']);

	if(x($opts,'infilesize'))
		@curl_setopt($ch, CURLOPT_INFILESIZE, $opts['infilesize']);

	if(x($opts,'readfunc'))
		@curl_setopt($ch, CURLOPT_READFUNCTION, $opts['readfunc']);

	// When using the session option and fetching from our own site,
	// append the PHPSESSID cookie to any existing headers.
	// Don't add to $opts['headers'] so that the cookie does not get
	// sent to other sites via redirects

	$instance_headers = ((array_key_exists('headers',$opts) && is_array($opts['headers'])) ? $opts['headers'] : []);

	if(x($opts,'session')) {
		if(strpos($url,z_root()) === 0) {
			$instance_headers[] = 'Cookie: PHPSESSID=' . session_id();
		}
	}
	if($instance_headers)
		@curl_setopt($ch, CURLOPT_HTTPHEADER, $instance_headers);


	if(x($opts,'nobody'))
		@curl_setopt($ch, CURLOPT_NOBODY, $opts['nobody']);

	if(x($opts,'custom'))
		@curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $opts['custom']);

	if(x($opts,'timeout') && intval($opts['timeout'])) {
		@curl_setopt($ch, CURLOPT_TIMEOUT, intval($opts['timeout']));
	}
	else {
		$curl_time = intval(@get_config('system','curl_timeout',60));
		@curl_setopt($ch, CURLOPT_TIMEOUT, $curl_time);
	}

	if(x($opts,'connecttimeout') && intval($opts['connecttimeout'])) {
		@curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, intval($opts['connecttimeout']));
	}
	else {
		$curl_contime = intval(@get_config('system','curl_connecttimeout',30));
		@curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $curl_contime);
	}


	if(x($opts,'http_auth')) {
		// "username" . ':' . "password"
		@curl_setopt($ch, CURLOPT_USERPWD, $opts['http_auth']);
	}

	if(x($opts,'cookiejar'))
		@curl_setopt($ch, CURLOPT_COOKIEJAR, $opts['cookiejar']);
	if(x($opts,'cookiefile'))
		@curl_setopt($ch, CURLOPT_COOKIEFILE, $opts['cookiefile']);

	if(x($opts,'cookie'))
		@curl_setopt($ch, CURLOPT_COOKIE, $opts['cookie']);

	@curl_setopt($ch, CURLOPT_SSL_VERIFYPEER,
		((x($opts,'novalidate') && intval($opts['novalidate'])) ? false : true));

	$prx = @get_config('system','proxy');
	if(strlen($prx)) {
		@curl_setopt($ch, CURLOPT_HTTPPROXYTUNNEL, 1);
		@curl_setopt($ch, CURLOPT_PROXY, $prx);
		$prxusr = @get_config('system','proxyuser');
		if(strlen($prxusr))
			@curl_setopt($ch, CURLOPT_PROXYUSERPWD, $prxusr);
	}
	if($binary)
		@curl_setopt($ch, CURLOPT_BINARYTRANSFER,1);


	// don't let curl abort the entire application'
	// if it throws any errors.

	$s = @curl_exec($ch);

	$base = $s;
	$curl_info = @curl_getinfo($ch);
	$http_code = $curl_info['http_code'];
	//logger('fetch_url:' . $http_code . ' data: ' . $s);
	$header = '';

	// For file redirects, set curl to follow location (indicated by $passthru).
	// Then just return success or failure.
	
	if ($passthru) {
		if ($http_code >= 200 && $http_code < 300) {
			$ret['success'] = true;
		}
		$ret['return_code'] = $http_code;
		@curl_close($ch);					
		return $ret;
	}
		

	// Pull out multiple headers, e.g. proxy and continuation headers
	// allow for HTTP/2.x without fixing code

	while(preg_match('/^HTTP\/[1-3][\.0-9]* [1-5][0-9][0-9]/',$base)) {
		$chunk = substr($base,0,strpos($base,"\r\n\r\n")+4);
		$header .= $chunk;
		$base = substr($base,strlen($chunk));
	}

	if($http_code == 301 || $http_code == 302 || $http_code == 303 || $http_code == 307 || $http_code == 308) {
		$matches = [];
		preg_match('/(Location:|URI:)(.*?)\n/i', $header, $matches);
		$newurl = trim(array_pop($matches));
		if(strpos($newurl,'/') === 0) {
			// We received a redirect to a relative path.
			// Find the base component of the original url and re-assemble it with the new location
			$base = @parse_url($url);
			if ($base) {
				unset($base['path']); unset($base['query']); unset($base['fragment']);
				$newurl = unparse_url($base) . $newurl;
			}
		}
		if ($newurl) {
			@curl_close($ch);			
			return z_fetch_url($newurl,$binary,++$redirects,$opts);
		}
	}

	$rc = intval($http_code);
	$ret['return_code'] = $rc;
	$ret['success'] = (($rc >= 200 && $rc <= 299) ? true : false);
	if(! $ret['success']) {
		$ret['error'] = curl_error($ch);
		$ret['debug'] = $curl_info;
		$dbg = [ 
			'url' => $ret['debug']['url'],
			'content_type' => $ret['debug']['content_type'],
			'error_code'  => $ret['debug']['error_code'],
			'request_header' => $ret['debug']['request_header']
		];
		logger('z_fetch_url: error: ' . $url . ': ' . $ret['error'], LOGGER_DEBUG);
		logger('z_fetch_url: debug: ' . print_r($dbg,true), LOGGER_DATA);
	}
	$ret['body'] = substr($s,strlen($header));
	$ret['header'] = $header;
	$ret['request_target'] = $opts['request_target'];

	if(x($opts,'debug')) {
		$ret['debug'] = $curl_info;
	}

	@curl_close($ch);
	return($ret);
}


/**
 * @brief Does a curl post request.
 *
 * @param string $url
 *    URL to post
 * @param mixed $params
 *   The full data to post in a HTTP "POST" operation. This parameter can
 *   either be passed as a urlencoded string like 'para1=val1&para2=val2&...'
 *   or as an array with the field name as key and field data as value. If value
 *   is an array, the Content-Type header will be set to multipart/form-data.
 * @param int $redirects = 0
 *    internal use, recursion counter
 * @param array $opts (optional parameters)
 *    'timeout' => int seconds, default system config value or 60 seconds
 *    'http_auth' => username:password
 *    'novalidate' => do not validate SSL certs, default is to validate using our CA list
 *    'filep' => stream resource to write body to. header and body are not returned when using this option.
 *    'custom' => custom request method: e.g. 'PUT', 'DELETE'
 *
 * @return array an associative array with:
 *  * \e int \b return_code => HTTP return code or 0 if timeout or failure
 *  * \e boolean \b success => boolean true (if HTTP 2xx result) or false
 *  * \e string \b header => HTTP headers
 *  * \e string \b body => content
 *  * \e string \b debug => from curl_info()
 */
function z_post_url($url, $params, $redirects = 0, $opts = []) {

//	logger('url: ' . $url);
//	logger('params: ' . print_r($params,true));
//	logger('opts: ' . print_r($opts,true));

	$ret = array('return_code' => 0, 'success' => false, 'header' => "", 'body' => "");

	$ch = curl_init($url);
	if(($redirects > 8) || (! $ch))
		return $ret;

	if(! array_key_exists('request_target',$opts)) {
		$opts['request_target'] = 'post ' . get_request_string($url);
	}


	@curl_setopt($ch, CURLOPT_HEADER, true);
	@curl_setopt($ch, CURLINFO_HEADER_OUT, true);
	@curl_setopt($ch, CURLOPT_CAINFO, get_capath());
	@curl_setopt($ch, CURLOPT_RETURNTRANSFER,true);
	@curl_setopt($ch, CURLOPT_POST,1);
	@curl_setopt($ch, CURLOPT_POSTFIELDS,$params);
	@curl_setopt($ch, CURLOPT_ENCODING, '');
	
	$ciphers = @get_config('system','curl_ssl_ciphers');
	if($ciphers)
		@curl_setopt($ch, CURLOPT_SSL_CIPHER_LIST, $ciphers);

	if(x($opts,'filep')) {
		@curl_setopt($ch, CURLOPT_FILE, $opts['filep']);
		@curl_setopt($ch, CURLOPT_HEADER, false);
	}

	if (x($opts['useragent'])) {
		@curl_setopt($ch, CURLOPT_USERAGENT, $opts['useragent']);
	}
	else {
		@curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (compatible; zot)");
	}


	$instance_headers = ((array_key_exists('headers',$opts) && is_array($opts['headers'])) ? $opts['headers'] : []);

	if(x($opts,'session')) {
		if(strpos($url,z_root()) === 0) {
			$instance_headers[] = 'Cookie: PHPSESSID=' . session_id();
		}
	}
	if($instance_headers)
		@curl_setopt($ch, CURLOPT_HTTPHEADER, $instance_headers);


	if(x($opts,'nobody'))
		@curl_setopt($ch, CURLOPT_NOBODY, $opts['nobody']);

	if(x($opts,'custom')) {
		@curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $opts['custom']);
		@curl_setopt($ch, CURLOPT_POST,0);
	}

	if(x($opts,'timeout') && intval($opts['timeout'])) {
		@curl_setopt($ch, CURLOPT_TIMEOUT, intval($opts['timeout']));
	}
	else {
		$curl_time = intval(@get_config('system','curl_timeout',60));
		@curl_setopt($ch, CURLOPT_TIMEOUT, $curl_time);
	}

	if(x($opts,'connecttimeout') && intval($opts['connecttimeout'])) {
		@curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, intval($opts['connecttimeout']));
	}
	else {
		$curl_contime = intval(@get_config('system','curl_connecttimeout',30));
		@curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $curl_contime);
	}

	if(x($opts,'http_auth')) {
		// "username" . ':' . "password"
		@curl_setopt($ch, CURLOPT_USERPWD, $opts['http_auth']);
	}

	if(x($opts,'cookiejar'))
		@curl_setopt($ch, CURLOPT_COOKIEJAR, $opts['cookiejar']);
	if(x($opts,'cookiefile'))
		@curl_setopt($ch, CURLOPT_COOKIEFILE, $opts['cookiefile']);
	if(x($opts,'cookie'))
		@curl_setopt($ch, CURLOPT_COOKIE, $opts['cookie']);

	@curl_setopt($ch, CURLOPT_SSL_VERIFYPEER,
		((x($opts,'novalidate') && intval($opts['novalidate'])) ? false : true));

	$prx = get_config('system','proxy');
	if(strlen($prx)) {
		@curl_setopt($ch, CURLOPT_HTTPPROXYTUNNEL, 1);
		@curl_setopt($ch, CURLOPT_PROXY, $prx);
		$prxusr = get_config('system','proxyuser');
		if(strlen($prxusr))
			@curl_setopt($ch, CURLOPT_PROXYUSERPWD, $prxusr);
	}

	// don't let curl abort the entire application
	// if it throws any errors.

	$s = @curl_exec($ch);

	$base = $s;
	$curl_info = @curl_getinfo($ch);
	$http_code = $curl_info['http_code'];

	$header = '';

	// Pull out multiple headers, e.g. proxy and continuation headers
	// allow for HTTP/2.x without fixing code

	while(preg_match('/^HTTP\/[1-3][\.0-9]* [1-5][0-9][0-9]/',$base)) {
		$chunk = substr($base,0,strpos($base,"\r\n\r\n")+4);
		$header .= $chunk;
		$base = substr($base,strlen($chunk));
	}

	// would somebody take lighttpd and just shoot it?

	if($http_code == 417) {
		curl_close($ch);
		if($opts) {
			if($opts['headers'])
				$opts['headers'][] = 'Expect:';
			else
				$opts['headers'] = array('Expect:');
		}
		else
			$opts = array('headers' => array('Expect:'));
		return z_post_url($url,$params,++$redirects,$opts);
	}

	if($http_code == 301 || $http_code == 302 || $http_code == 303 || $http_code == 307 || $http_code == 308) {
		$matches = [];
		preg_match('/(Location:|URI:)(.*?)\n/', $header, $matches);
		$newurl = trim(array_pop($matches));
		if(strpos($newurl,'/') === 0) {
			// We received a redirect to a relative path.
			// Find the base component of the original url and re-assemble it with the new location
			$base = @parse_url($url);
			if ($base) {
				unset($base['path']); unset($base['query']); unset($base['fragment']);
				$newurl = unparse_url($base) . $newurl;
			}
		}
		if ($newurl) {
			curl_close($ch);
			if($http_code == 303) {
				return z_fetch_url($newurl,false,++$redirects,$opts);
			}
			else {
				return z_post_url($newurl,$params,++$redirects,$opts);
			}
		}
	}
	$rc = intval($http_code);
	$ret['return_code'] = $rc;
	$ret['success'] = (($rc >= 200 && $rc <= 299) ? true : false);
	if(! $ret['success']) {
		$ret['error'] = curl_error($ch);
		$ret['debug'] = $curl_info;
		$dbg = [ 
			'url' => $ret['debug']['url'],
			'content_type' => $ret['debug']['content_type'],
			'error_code'  => $ret['debug']['error_code'],
			'request_header' => $ret['debug']['request_header']
		];
		logger('z_post_url: error: ' . $url . ': ' . $ret['error'], LOGGER_DEBUG);
		logger('z_post_url: debug: ' . print_r($dbg,true), LOGGER_DATA);
	}

	$ret['body'] = substr($s, strlen($header));
	$ret['header'] = $header;
	$ret['request_target'] = $opts['request_target'];

	if(x($opts,'debug')) {
		$ret['debug'] = $curl_info;
	}

	curl_close($ch);
	return($ret);
}

function json_return_and_die($x, $content_type = 'application/json', $debug = false) {
	header("Content-type: $content_type");
	if ($debug) {
		logger('returned_json: ' . json_encode($x,JSON_PRETTY_PRINT|JSON_UNESCAPED_SLASHES), LOGGER_DATA);
	}
	echo json_encode($x);
	killme();
}

function as_return_and_die($obj,$channel) {

	$x = array_merge(['@context' => [
		ACTIVITYSTREAMS_JSONLD_REV,
		'https://w3id.org/security/v1',
		Activity::ap_schema()
		]], $obj );

	$headers = [];
	$headers['Content-Type'] = 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"' ;
	$x['signature'] = LDSignatures::sign($x,$channel);
	$ret = json_encode($x, JSON_UNESCAPED_SLASHES);
	logger('data: ' . jindent($ret), LOGGER_DATA);
	$headers['Date'] = datetime_convert('UTC','UTC', 'now', 'D, d M Y H:i:s \\G\\M\\T');
	$headers['Digest'] = HTTPSig::generate_digest_header($ret);
	$headers['(request-target)'] = strtolower($_SERVER['REQUEST_METHOD']) . ' ' . $_SERVER['REQUEST_URI'];

	$h = HTTPSig::create_sig($headers,$channel['channel_prvkey'],channel_url($channel));
	HTTPSig::set_headers($h);

	echo $ret;
	killme();

}


/**
 * @brief Send HTTP status header.
 *
 * @param int $val
 *    integer HTTP status result value
 * @param string $msg
 *    optional message
 */
function http_status($val, $msg = '') {
	if ($val >= 400)
		$msg = (($msg) ? $msg : 'Error');
	if ($val >= 200 && $val < 300)
		$msg = (($msg) ? $msg : 'OK');

	logger(\App::$query_string . ':' . $val . ' ' . $msg);
	header($_SERVER['SERVER_PROTOCOL'] . ' ' . $val . ' ' . $msg);
}


/**
 * @brief Send HTTP status header and exit.
 *
 * @param int $val
 *    integer HTTP status result value
 * @param string $msg
 *    optional message
 * @return void does not return, process is terminated
 */
function http_status_exit($val, $msg = '') {
	http_status($val, $msg);
	killme();
}

/*
 *
 * Takes the output of parse_url and builds a URL from it
 *
 */
 
function unparse_url($parsed_url) {
	$scheme   = isset($parsed_url['scheme']) ? $parsed_url['scheme'] . '://' : '';
	$host     = isset($parsed_url['host']) ? $parsed_url['host'] : '';
	$port     = ((isset($parsed_url['port']) && intval($parsed_url['port'])) ? ':' . intval($parsed_url['port']) : '');
	$user     = isset($parsed_url['user']) ? $parsed_url['user'] : '';
	$pass     = isset($parsed_url['pass']) ? ':' . $parsed_url['pass']  : '';
	$pass     = ($user || $pass) ? "$pass@" : '';
	$path     = isset($parsed_url['path']) ? $parsed_url['path'] : '';
	$query    = isset($parsed_url['query']) ? '?' . $parsed_url['query'] : '';
	$fragment = isset($parsed_url['fragment']) ? '#' . $parsed_url['fragment'] : '';
  	return "$scheme$user$pass$host$port$path$query$fragment";
} 





/**
 * @brief Convert an XML document to a normalised, case-corrected array used by webfinger.
 *
 * @param string|array|SimpleXMLElement $xml_element
 * @param[in,out] int $recursion_depth
 * @return NULL|string|array
 */
function convert_xml_element_to_array($xml_element, &$recursion_depth=0) {

	// If we're getting too deep, bail out
	if ($recursion_depth > 512) {
		return(null);
	}

	if (!is_string($xml_element) &&
			!is_array($xml_element) &&
			(get_class($xml_element) == 'SimpleXMLElement')) {
		$xml_element_copy = $xml_element;
		$xml_element = get_object_vars($xml_element);
	}

	if (is_array($xml_element)) {
		$result_array = [];
		if (count($xml_element) <= 0) {
			return (trim(strval($xml_element_copy)));
		}

		foreach($xml_element as $key=>$value) {
			$recursion_depth++;
			$result_array[strtolower($key)] =
				convert_xml_element_to_array($value, $recursion_depth);
			$recursion_depth--;
		}
		if ($recursion_depth == 0) {
			$temp_array = $result_array;
			$result_array = array(
				strtolower($xml_element_copy->getName()) => $temp_array,
			);
		}

		return ($result_array);
	} else {
		return (trim(strval($xml_element)));
	}
}



function z_dns_check($h,$check_mx = 0) {

	// dns_get_record() has issues on some platforms
	// so allow somebody to ignore it completely
	// Use config values from memory as this can be called during setup
	// before a database or even any config structure exists.

	if(is_array(App::$config) && array_path_exists('system/do_not_check_dns', App::$config) && App::$config['system']['do_not_check_dns'])
		return true;

	// This will match either Windows or Mac ('Darwin')
	if(stripos(PHP_OS,'win') !== false)
		return true;

	// BSD variants have dns_get_record() but it only works reliably without any options
	if(stripos(PHP_OS,'bsd') !== false)
		return((@dns_get_record($h) || filter_var($h, FILTER_VALIDATE_IP)) ? true : false);

	// Otherwise we will assume dns_get_record() works as documented

	$opts = DNS_A + DNS_CNAME + DNS_AAAA;
	if($check_mx)
		$opts += DNS_MX;

	return((@dns_get_record($h,$opts) || filter_var($h, FILTER_VALIDATE_IP)) ? true : false);
}

/**
 * @brief Validates a given URL.
 *
 * Take a URL from the wild, prepend http:// if necessary and check DNS to see
 * if it's real (or check if is a valid IP address).
 *
 * @see z_dns_check()
 *
 * @param[in,out] string $url URL to check
 * @return boolean Return true if it's OK, false if something is wrong with it
 */
function validate_url(&$url) {

	// no naked subdomains (allow localhost for tests)
	if(strpos($url, '.') === false && strpos($url, '/localhost/') === false)
		return false;

	if(substr($url, 0, 4) != 'http')
		$url = 'http://' . $url;

	$h = @parse_url($url);

	if(($h) && z_dns_check($h['host'])) {
		return true;
	}

	return false;
}

/**
 * @brief Checks that email is an actual resolvable internet address.
 *
 * @param string $addr
 * @return boolean
 */
function validate_email($addr) {

	if(get_config('system', 'disable_email_validation'))
		return true;

	if(! strpos($addr, '@'))
		return false;

	$h = substr($addr, strpos($addr, '@') + 1);

	if(($h) && z_dns_check($h, true)) {
		return true;
	}

	return false;
}

/**
 * @brief Check if email address is allowed to register here.
 *
 * Compare against our list (wildcards allowed).
 *
 * @param string $email
 * @return boolean Returns false if not allowed, true if allowed or if allowed list is
 * not configured.
 */
function allowed_email($email) {

	$domain = strtolower(substr($email, strpos($email, '@') + 1));
	if(! $domain)
		return false;

	$str_allowed = get_config('system', 'allowed_email');
	$str_not_allowed = get_config('system', 'not_allowed_email');

	if(! $str_allowed && ! $str_not_allowed)
		return true;

	$return = false;
	$found_allowed = false;
	$found_not_allowed = false;

	$fnmatch = function_exists('fnmatch');

	$allowed = explode(',', $str_allowed);

	if(count($allowed)) {
		foreach($allowed as $a) {
			$pat = strtolower(trim($a));
			if(($fnmatch && fnmatch($pat,$email)) || ($pat == $domain)) {
				$found_allowed = true;
				break;
			}
		}
	}

	$not_allowed = explode(',', $str_not_allowed);

	if(count($not_allowed)) {
		foreach($not_allowed as $na) {
			$pat = strtolower(trim($na));
			if(($fnmatch && fnmatch($pat,$email)) || ($pat == $domain)) {
				$found_not_allowed = true;
				break;
			}
		}
	}

	if ($found_allowed) {
		$return = true;
	} elseif (!$str_allowed && !$found_not_allowed) {
		$return = true;
	}

	return $return;
}



function parse_xml_string($s, $strict = true) {
	if($strict) {
		if(! strstr($s,'<?xml'))
			return false;

		$s2 = substr($s,strpos($s,'<?xml'));
	}
	else
		$s2 = $s;

	libxml_use_internal_errors(true);


	$x = @simplexml_load_string($s2);
	if($x === false) {
		logger('libxml: parse: error: ' . $s2, LOGGER_DATA);
		foreach(libxml_get_errors() as $err) {
			logger('libxml: parse: ' . $err->code . ' at ' . $err->line
				. ':' . $err->column . ' : ' . $err->message, LOGGER_DATA);
		}
		libxml_clear_errors();
	}

	return $x;
}


function sxml2array ( $xmlObject, $out = array () )
{
    foreach ( (array) $xmlObject as $index => $node )
        $out[$index] = ( is_object ( $node ) ) ? sxml2array ( $node ) : $node;

    return $out;
}

/**
 * @brief xml2[] will convert the given XML text to an array in the XML structure.
 *
 * Link: http://www.bin-co.com/php/scripts/xml2array/
 * Portions significantly re-written by mike@macgirvin.com 
 * (namespaces, lowercase tags, get_attribute default changed, more...)
 *
 * Examples: $array =  xml2array(file_get_contents('feed.xml'));
 *           $array =  xml2array(file_get_contents('feed.xml', true, 1, 'attribute'));
 *
 * @param string $contents The XML text
 * @param boolean $namespaces true or false include namespace information in the returned array as array elements
 * @param int $get_attributes 1 or 0. If this is 1 the function will get the attributes as well as the tag values - this results in a different array structure in the return value.
 * @param string $priority Can be 'tag' or 'attribute'. This will change the way the resulting array sturcture. For 'tag', the tags are given more importance.
 *
 * @return array The parsed XML in an array form. Use print_r() to see the resulting array structure.
 */
function xml2array($contents, $namespaces = true, $get_attributes=1, $priority = 'attribute') {
	if(!$contents)
		return [];

	if(!function_exists('xml_parser_create')) {
		logger('xml2array: parser function missing');
		return [];
	}

	libxml_use_internal_errors(true);
	libxml_clear_errors();

	if($namespaces)
		$parser = @xml_parser_create_ns("UTF-8",':');
	else
		$parser = @xml_parser_create();

	if(! $parser) {
		logger('xml2array: xml_parser_create: no resource');
		return [];
	}

	xml_parser_set_option($parser, XML_OPTION_TARGET_ENCODING, "UTF-8");
	// http://minutillo.com/steve/weblog/2004/6/17/php-xml-and-character-encodings-a-tale-of-sadness-rage-and-data-loss
	xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, 0);
	xml_parser_set_option($parser, XML_OPTION_SKIP_WHITE, 1);
	@xml_parse_into_struct($parser, trim($contents), $xml_values);
	@xml_parser_free($parser);

	if(! $xml_values) {
		logger('xml2array: libxml: parse error: ' . $contents, LOGGER_DATA);
		foreach(libxml_get_errors() as $err)
			logger('libxml: parse: ' . $err->code . " at " . $err->line . ":" . $err->column . " : " . $err->message, LOGGER_DATA);
		libxml_clear_errors();

		return;
	}

	//Initializations
	$xml_array = [];
	$parents = [];
	$opened_tags = [];
	$arr = [];

	$current = &$xml_array; // Reference

	// Go through the tags.
	$repeated_tag_index = []; // Multiple tags with same name will be turned into an array
	foreach($xml_values as $data) {
		unset($attributes,$value); // Remove existing values, or there will be trouble

		// This command will extract these variables into the foreach scope
		// tag(string), type(string), level(int), attributes(array).
		extract($data); // We could use the array by itself, but this cooler.

		$result = [];
		$attributes_data = [];

		if(isset($value)) {
			if($priority == 'tag') $result = $value;
			else $result['value'] = $value; // Put the value in a assoc array if we are in the 'Attribute' mode
		}

		//Set the attributes too.
		if(isset($attributes) and $get_attributes) {
			foreach($attributes as $attr => $val) {
				if($priority == 'tag') $attributes_data[$attr] = $val;
				else $result['@attributes'][$attr] = $val; // Set all the attributes in a array called 'attr'
			}
		}

		// See tag status and do the needed.
		if($namespaces && strpos($tag,':')) {
			$namespc = substr($tag,0,strrpos($tag,':'));
			$tag = strtolower(substr($tag,strlen($namespc)+1));
			$result['@namespace'] = $namespc;
		}
		$tag = strtolower($tag);

		if($type == "open") {   // The starting of the tag '<tag>'
			$parent[$level-1] = &$current;
			if(!is_array($current) or (!in_array($tag, array_keys($current)))) { // Insert New tag
				$current[$tag] = $result;
				if($attributes_data) $current[$tag. '_attr'] = $attributes_data;
				$repeated_tag_index[$tag.'_'.$level] = 1;

				$current = &$current[$tag];

			} else { // There was another element with the same tag name

				if(isset($current[$tag][0])) { // If there is a 0th element it is already an array
					$current[$tag][$repeated_tag_index[$tag.'_'.$level]] = $result;
					$repeated_tag_index[$tag.'_'.$level]++;
				} else { // This section will make the value an array if multiple tags with the same name appear together
					$current[$tag] = array($current[$tag],$result); // This will combine the existing item and the new item together to make an array
					$repeated_tag_index[$tag.'_'.$level] = 2;

					if(isset($current[$tag.'_attr'])) { // The attribute of the last(0th) tag must be moved as well
						$current[$tag]['0_attr'] = $current[$tag.'_attr'];
						unset($current[$tag.'_attr']);
					}
				}
				$last_item_index = $repeated_tag_index[$tag.'_'.$level]-1;
				$current = &$current[$tag][$last_item_index];
			}

		} elseif($type == "complete") { // Tags that ends in 1 line '<tag />'
			//See if the key is already taken.
			if(!isset($current[$tag])) { //New Key
				$current[$tag] = $result;
				$repeated_tag_index[$tag.'_'.$level] = 1;
				if($priority == 'tag' and $attributes_data)
					$current[$tag. '_attr'] = $attributes_data;

			} else { // If taken, put all things inside a list(array)
				if(isset($current[$tag][0]) and is_array($current[$tag])) { // If it is already an array...

					// ...push the new element into that array.
					$current[$tag][$repeated_tag_index[$tag.'_'.$level]] = $result;

					if($priority == 'tag' and $get_attributes and $attributes_data) {
						$current[$tag][$repeated_tag_index[$tag.'_'.$level] . '_attr'] = $attributes_data;
					}
					$repeated_tag_index[$tag.'_'.$level]++;
				} else { // If it is not an array...
					$current[$tag] = array($current[$tag],$result); //...Make it an array using using the existing value and the new value
					$repeated_tag_index[$tag.'_'.$level] = 1;
					if($priority == 'tag' and $get_attributes) {
						if(isset($current[$tag.'_attr'])) { // The attribute of the last(0th) tag must be moved as well
							$current[$tag]['0_attr'] = $current[$tag.'_attr'];
							unset($current[$tag.'_attr']);
						}

						if($attributes_data) {
							$current[$tag][$repeated_tag_index[$tag.'_'.$level] . '_attr'] = $attributes_data;
						}
					}
					$repeated_tag_index[$tag.'_'.$level]++; // 0 and 1 indexes are already taken
				}
			}

		} elseif($type == 'close') { // End of tag '</tag>'
			$current = &$parent[$level-1];
		}
	}

	return($xml_array);
}


function email_header_encode($in_str, $charset = 'UTF-8', $header = 'Subject') {
	$out_str = $in_str;
	$need_to_convert = false;

	for($x = 0; $x < strlen($in_str); $x ++) {
		if((ord($in_str[$x]) == 0) || ((ord($in_str[$x]) > 128))) {
			$need_to_convert = true;
			break;
		}
	}

	if(! $need_to_convert)
		return $in_str;

	if ($out_str && $charset) {

		// define start delimimter, end delimiter and spacer
		$end = "?=";
		$start = "=?" . $charset . "?B?";
		$spacer = $end . PHP_EOL . " " . $start;

		// determine length of encoded text within chunks
		// and ensure length is even
		$length = 75 - strlen($start) - strlen($end) - (strlen($header) + 2);

		/*
			[EDIT BY danbrown AT php DOT net: The following
			is a bugfix provided by (gardan AT gmx DOT de)
			on 31-MAR-2005 with the following note:
			"This means: $length should not be even,
			but divisible by 4. The reason is that in
			base64-encoding 3 8-bit-chars are represented
			by 4 6-bit-chars. These 4 chars must not be
			split between two encoded words, according
			to RFC-2047.
		*/
		$length = $length - ($length % 4);

		// encode the string and split it into chunks
		// with spacers after each chunk
		$out_str = base64_encode($out_str);
		$out_str = chunk_split($out_str, $length, $spacer);

		// remove trailing spacer and
		// add start and end delimiters
		$spacer = preg_quote($spacer,'/');
		$out_str = preg_replace("/" . $spacer . "$/", "", $out_str);
		$out_str = $start . $out_str . $end;
	}
	return $out_str;
}

/**
 * @brief
 *
 * @param string $webbie
 * @param string $protocol (optional) default empty
 * @param boolean $verify (optional) default true, verify HTTP signatures on Zot discovery packets.
 * @return boolean
 */
function discover_by_webbie($webbie, $protocol = '', $verify = true) {

	$result   = [];

	$network  = null;

	$x = Webfinger::exec($webbie);

 	$address = EMPTY_STR;

	if($x && array_key_exists('subject',$x) && strpos($x['subject'],'acct:') === 0)
        $address = str_replace('acct:','',$x['subject']);
    if($x && array_key_exists('aliases',$x) && count($x['aliases'])) {
        foreach($x['aliases'] as $a) {
            if(strpos($a,'acct:') === 0) {
                $address = str_replace('acct:','',$a);
                break;
            }
        }
    }

	if($x && array_key_exists('links',$x) && is_array($x['links'])) {
		foreach($x['links'] as $link) {
			if(array_key_exists('rel',$link)) {

				$apurl = null;

				// If we discover zot - don't search further; grab the info and get out of
				// here.

				if($link['rel'] === PROTOCOL_ZOT6 && ((! $protocol) || (strtolower($protocol) === 'zot6'))) {
					logger('zot6 found for ' . $webbie, LOGGER_DEBUG);
					$record = Zotfinger::exec($link['href'], null, $verify);

					// Check the HTTP signature

					if ($verify) {

						$hsig = $record['signature'];
						if($hsig && ($hsig['signer'] === $url || $hsig['signer'] === $link['href']) && $hsig['header_valid'] === true && $hsig['content_valid'] === true) {
							$hsig_valid = true;
						}

						if(! $hsig_valid) {
							logger('http signature not valid: ' . print_r($hsig,true));
							continue;
						}
					}

					$x = Libzot::import_xchan($record['data']);
					if($x['success']) {
						return $x['hash'];
					}
				}
				if($link['rel'] === 'self' && ($link['type'] === 'application/activity+json' || strpos($link['type'],'ld+json') !== false) && ((! $protocol) || (strtolower($protocol) === 'activitypub'))) {
					$ap = ActivityPub::discover($link['href']);
					if($ap) {
						return $ap;
					}
				}
			}
		}
	}

	if(strpos($webbie,'http') === 0) {
		$ap = ActivityPub::discover($webbie);
		if($ap) {
			return $ap;
		}
	}

	logger('webfinger: ' . print_r($x,true), LOGGER_DATA, LOG_INFO);

	$arr = [
			'address'   => $webbie,
			'protocol'  => $protocol,
			'success'   => false,
			'xchan'     => '',
			'webfinger' => $x
	];
	/**
	 * @hooks discover_channel_webfinger
	 *   Called when performing a webfinger lookup.
	 *   * \e string \b address - The webbie
	 *   * \e string \b protocol
	 *   * \e array \b webfinger - The result from webfinger_rfc7033()
	 *   * \e boolean \b success - The return value, default false
	 */
	call_hooks('discover_channel_webfinger', $arr);
	if($arr['success'])
		return $arr['xchan'];

	return false;
}

/**
 * @brief Fetch and return a webfinger for a webbie.
 * No longer used - see Zotlabs/Lib/Webfinger.php
 *
 * @param string $webbie - The resource
 * @return boolean|string false or associative array from result JSON
 */
function webfinger_rfc7033($webbie) {

	if(strpos($webbie,'@')) {
		$lhs = substr($webbie,0,strpos($webbie,'@'));
		$rhs = substr($webbie,strpos($webbie,'@')+1);
		$resource = urlencode('acct:' . $webbie);
	}
	else {
		$m = parse_url($webbie);
		if($m) {
			if($m['scheme'] !== 'https')
				return false;

			$rhs = $m['host'] . ((isset($m['port']) && intval($m['port'])) ? ':' . intval($m['port']) : '');
			$resource = urlencode($webbie);
		}
		else
			return false;
	}
	logger('fetching url from resource: ' . $rhs . ':' . $webbie);

	$counter = 0;
	$s = z_fetch_url('https://' . $rhs . '/.well-known/webfinger?f=&resource=' . $resource . (($zot) ? '&zot=1' : ''),
		false, $counter, [ 'headers' => [ 'Accept: application/jrd+json, application/json, */*' ] ]);

	if($s['success']) {
		$j = json_decode($s['body'], true);
		return($j);
	}

	return false;
}

function do_delivery($deliveries, $force = false) {

	// $force is set if a site that wasn't responding suddenly returns to life.
	// Try and shove through everything going to that site while it's responding. 

	if(! (is_array($deliveries) && count($deliveries)))
		return;


	$x = q("select count(outq_hash) as total from outq where outq_delivered = 0");
	if(intval($x[0]['total']) > intval(get_config('system','force_queue_threshold',3000)) && (! $force)) {
		logger('immediate delivery deferred.', LOGGER_DEBUG, LOG_INFO);
		foreach($deliveries as $d) {
			Queue::update($d);
		}
		return;
	}


	$interval = ((get_config('system','delivery_interval') !== false)
			? intval(get_config('system','delivery_interval')) : 2 );

	$deliveries_per_process = intval(get_config('system','delivery_batch_count'));

	if($deliveries_per_process <= 0)
		$deliveries_per_process = 1;


	$deliver = [];
	foreach($deliveries as $d) {

		if(! $d)
			continue;

		$deliver[] = $d;

		if(count($deliver) >= $deliveries_per_process) {
			Run::Summon( [ 'Deliver',$deliver ] );
			$deliver = [];
			if($interval)
				@time_sleep_until(microtime(true) + (float) $interval);
		}
	}

	// catch any stragglers

	if($deliver) {
		Run::Summon( [ 'Deliver',$deliver ] );
	}
}


function get_site_info() {

	$register_policy = Array('REGISTER_CLOSED', 'REGISTER_APPROVE', 'REGISTER_OPEN');
	$directory_mode = Array('DIRECTORY_MODE_NORMAL', 'DIRECTORY_MODE_PRIMARY', 'DIRECTORY_MODE_SECONDARY', 256 => 'DIRECTORY_MODE_STANDALONE');

	$sql_extra = '';

	$r = q("select * from channel left join account on account_id = channel_account_id where ( account_roles & 4096 ) > 0 and account_default_channel = channel_id");


	if($r) {
		$admin = [];
		foreach($r as $rr) {
			if($rr['channel_pageflags'] & PAGE_HUBADMIN)
				$admin[] = array( 'name' => $rr['channel_name'], 'address' => channel_reddress($rr), 'channel' => z_root() . '/channel/' . $rr['channel_address']);
		}
		if(! $admin) {
			foreach($r as $rr) {
				$admin[] = array( 'name' => $rr['channel_name'], 'address' => channel_reddress($rr), 'channel' => z_root() . '/channel/' . $rr['channel_address']);
			}
		}
	}
	else {
		$admin = false;
	}

	$def_service_class = get_config('system','default_service_class');
	if($def_service_class)
		$service_class = get_config('service_class',$def_service_class);
	else
		$service_class = false;

	$visible_plugins = visible_plugin_list();

	if(@is_dir('.git') && function_exists('shell_exec'))
		$commit = trim(@shell_exec('git log -1 --format="%h"'));
	if(! isset($commit) || strlen($commit) > 16)
		$commit = '';

	$site_info = get_config('system','info');
	$site_name = get_config('system','sitename');
	if(! get_config('system','hidden_version_siteinfo')) {
		$version = System::get_project_version();

		if(@is_dir('.git') && function_exists('shell_exec')) {
			$commit = trim( @shell_exec('git log -1 --format="%h"'));
		}

		if(! isset($commit) || strlen($commit) > 16)
			$commit = '';
	}
	else {
		$version = $commit = '';
	}

	//Statistics
//	$channels_total_stat = intval(get_config('system','channels_total_stat'));
//	$channels_active_halfyear_stat = intval(get_config('system','channels_active_halfyear_stat'));
//	$channels_active_monthly_stat = intval(get_config('system','channels_active_monthly_stat'));
//	$local_posts_stat = intval(get_config('system','local_posts_stat'));
//	$local_comments_stat = intval(get_config('system','local_comments_stat'));
//	$hide_in_statistics = intval(get_config('system','hide_in_statistics'));

	$site_expire = intval(get_config('system', 'default_expire_days'));

	load_config('feature_lock');
	$locked_features = [];
	if(is_array(App::$config['feature_lock']) && count(App::$config['feature_lock'])) {
		foreach(App::$config['feature_lock'] as $k => $v) {
			if($k === 'config_loaded')
				continue;

			$locked_features[$k] = intval($v);
		}
	}

	$protocols = [ 'zot' ];
	if (get_config('system','activitypub', ACTIVITYPUB_ENABLED)) {
		$protocols[] = 'activitypub';
	}

	$data = [
		'url'                          => z_root(),
		'platform'                     => System::get_platform_name(),
		'site_name'                    => (($site_name) ? $site_name : ''),
		'version'                      => $version,
//		'version_tag'                  => $tag,
		'addon_version'                => defined('ADDON_VERSION') ? ADDON_VERSION : 'unknown',
		'server_role'                  => System::get_server_role(),
		'commit'                       => $commit,
		'protocols'                    => $protocols,
		'plugins'                      => $visible_plugins,
		'register_policy'              =>  $register_policy[get_config('system','register_policy')],
		'invitation_only'              => (bool) intval(get_config('system','invitation_only')),
		'directory_mode'               =>  $directory_mode[get_config('system','directory_mode')],
//		'directory_server'             => get_config('system','directory_server'),
		'language'                     => get_config('system','language'),
//		'rss_connections'              => (bool) intval(get_config('system','feed_contacts')),
		'expiration'                   => $site_expire,
		'default_service_restrictions' => $service_class,
		'locked_features'              => $locked_features,
		'admin'                        => $admin,
		'dbdriver'                     => DBA::$dba->getdriver() . ' ' . ((ACTIVE_DBTYPE == DBTYPE_POSTGRES) ? 'postgres' : 'mysql'),
		'lastpoll'                     => get_config('system','lastpoll'),
		'ebs'                          => System::ebs(),
		'info'                         => (($site_info) ? $site_info : '')

	];


	return $data;
}

/**
 * @brief
 *
 * @param string $url
 * @return boolean
 */
function check_siteallowed($url) {

	$retvalue = true;

	$arr = [ 'url' => $url ];
	/**
	 * @hooks check_siteallowed
	 *   Used to over-ride or bypass the site black/white block lists.
	 *   * \e string \b url
	 *   * \e boolean \b allowed - optional return value set in hook
	 */
	call_hooks('check_siteallowed', $arr);

	if (array_key_exists('allowed',$arr)) {
		return $arr['allowed'];
	}

	$bl1 = get_config('system','allowed_sites');
	if (is_array($bl1) && $bl1) {
		foreach ($bl1 as $bl) {
			if ($bl === '*') {
				$retvalue = true;
			}
			if ($bl && strpos($url,$bl) !== false)
				return true;
		}
	}
	$bl1 = get_config('system','denied_sites');
	if (is_array($bl1) && $bl1) {
		foreach ($bl1 as $bl) {
			if ($bl === '*') {
				$retvalue = false;
			}
			if ($bl && strpos($url,$bl) !== false) {
				return false;
			}
		}
	}

	return $retvalue;
}

/**
 * @brief
 *
 * @param string $url
 * @return boolean
 */
function check_pubstream_siteallowed($url) {

	$retvalue = true;

	$arr = array('url' => $url);
	/**
	 * @hooks check_siteallowed
	 *   Used to over-ride or bypass the site black/white block lists.
	 *   * \e string \b url
	 *   * \e boolean \b allowed - optional return value set in hook
	 */
	call_hooks('pubstream_check_siteallowed', $arr);

	if(array_key_exists('allowed',$arr))
		return $arr['allowed'];

	$bl1 = get_config('system','pubstream_allowed_sites');
	if(is_array($bl1) && $bl1) {
		foreach($bl1 as $bl) {
			if($bl === '*')
				$retvalue = true;
			if($bl && strpos($url,$bl) !== false)
				return true;
		}
	}
	$bl1 = get_config('system','pubstream_denied_sites');
	if(is_array($bl1) && $bl1) {
		foreach($bl1 as $bl) {
			if($bl === '*')
				$retvalue = false;
			if($bl && strpos($url,$bl) !== false) {
				return false;
			}
		}
	}

	return $retvalue;
}



/**
 * @brief
 *
 * @param string $hash
 * @return boolean
 */
function check_channelallowed($hash) {

	$retvalue = true;

	$arr = [ 'hash' => $hash ];
	/**
	 * @hooks check_channelallowed
	 *   Used to over-ride or bypass the channel black/white block lists.
	 *   * \e string \b hash
	 *   * \e boolean \b allowed - optional return value set in hook
	 */
	call_hooks('check_channelallowed', $arr);

	if (array_key_exists('allowed',$arr)) {
		return $arr['allowed'];
	}

	$bl1 = get_config('system','allowed_channels');
	if (is_array($bl1) && $bl1) {
		foreach ($bl1 as $bl) {
			if ($bl === '*') {
				$retvalue = true;
			}
			if ($bl && strpos($hash,$bl) !== false) {
				return true;
			}
		}
	}
	$bl1 = get_config('system','denied_channels');
	if (is_array($bl1) && $bl1) {
		foreach ($bl1 as $bl) {
			if ($bl === '*') {
				$retvalue = false;
			}
			if ($bl && strpos($hash,$bl) !== false) {
				return false;
			}
		}
	}

	return $retvalue;
}


/**
 * @brief
 *
 * @param string $hash
 * @return boolean
 */
function check_pubstream_channelallowed($hash) {

	$retvalue = true;

	$arr = array('hash' => $hash);
	/**
	 * @hooks check_channelallowed
	 *   Used to over-ride or bypass the channel black/white block lists.
	 *   * \e string \b hash
	 *   * \e boolean \b allowed - optional return value set in hook
	 */
	call_hooks('check_pubstream_channelallowed', $arr);

	if(array_key_exists('allowed',$arr))
		return $arr['allowed'];

	$bl1 = get_config('system','pubstream_allowed_channels');
	if(is_array($bl1) && $bl1) {
		foreach($bl1 as $bl) {
			if($bl === '*')
				$retvalue = true;
			if($bl && strpos($hash,$bl) !== false)
				return true;
		}
	}
	$bl1 = get_config('system','pubstream_denied_channels');
	if(is_array($bl1) && $bl1) {
		foreach($bl1 as $bl) {
			if($bl === '*')
				$retvalue = false;
			if($bl && strpos($hash,$bl) !== false) {
				return false;
			}
		}
	}

	return $retvalue;
}


function deliverable_singleton($channel_id,$xchan) {

	if(array_key_exists('xchan_hash',$xchan))
		$xchan_hash = $xchan['xchan_hash'];
	elseif(array_key_exists('hubloc_hash',$xchan))
		$xchan_hash = $xchan['hubloc_hash'];
	else
		return true;

	$r = q("select abook_instance from abook where abook_channel = %d and abook_xchan = '%s' limit 1",
		intval($channel_id),
		dbesc($xchan_hash)
	);
	if($r) {
		if(! $r[0]['abook_instance'])
			return true;
		if(strpos($r[0]['abook_instance'],z_root()) !== false)
			return true;
	}
	return false;
}



function get_repository_version($branch = 'release') {

	$path = "https://codeberg.org/zot/" . ((PLATFORM_NAME === 'mistpark') ? 'misty' : PLATFORM_NAME) . "/raw/$branch/boot.php";

	$x = z_fetch_url($path);
	if($x['success']) {
		$y = preg_match('/define(.*?)STD_VERSION(.*?)([0-9.].*)\'/',$x['body'],$matches);
		if($y)
			return $matches[3];
	}
	return '?.?';
}

/**
 * @brief Get translated network name.
 *
 * @param string $s Network string, see boot.php
 * @return string Translated name of the network
 */
function network_to_name($s) {

	$nets = array(
		NETWORK_DFRN        => t('Friendica'),
		NETWORK_FRND        => t('Friendica'),
		NETWORK_OSTATUS     => t('OStatus'),
		NETWORK_GNUSOCIAL   => t('GNU-Social'),
		NETWORK_FEED        => t('RSS/Atom'),
		NETWORK_ACTIVITYPUB => t('ActivityPub'),
		NETWORK_MAIL        => t('Email'),
		NETWORK_DIASPORA    => t('Diaspora'),
		NETWORK_FACEBOOK    => t('Facebook'),
		NETWORK_ZOT         => t('Zot'),
		NETWORK_LINKEDIN    => t('LinkedIn'),
		NETWORK_XMPP        => t('XMPP/IM'),
		NETWORK_MYSPACE     => t('MySpace'),
	);

	/**
	 * @hooks network_to_name
	 * @deprecated
	 */
	call_hooks('network_to_name', $nets);

	$search  = array_keys($nets);
	$replace = array_values($nets);

	return str_replace($search, $replace, $s);
}

/**
 * @brief Send a text email message.
 *
 * @param array $params an associative array with:
 *  * \e string \b fromName        name of the sender
 *  * \e string \b fromEmail       email of the sender
 *  * \e string \b replyTo         replyTo address to direct responses
 *  * \e string \b toEmail         destination email address
 *  * \e string \b messageSubject  subject of the message
 *  * \e string \b htmlVersion     html version of the message
 *  * \e string \b textVersion     text only version of the message
 *  * \e string \b additionalMailHeader  additions to the smtp mail header
 */
function z_mail($params) {

	if(! $params['fromEmail']) {
		$params['fromEmail'] = get_config('system','from_email');
		if(! $params['fromEmail'])
			$params['fromEmail'] = 'Administrator' . '@' . App::get_hostname();
	}
	if(! $params['fromName']) {
		$params['fromName'] = get_config('system','from_email_name');
		if(! $params['fromName'])
			$params['fromName'] = System::get_site_name();
	}
	if(! $params['replyTo']) {
		$params['replyTo'] = get_config('system','reply_address');
		if(! $params['replyTo'])
			$params['replyTo'] = 'noreply' . '@' . App::get_hostname();
	}

	$params['sent']   = false;
	$params['result'] = false;

	/**
	 * @hooks email_send
	 *   * \e params @see z_mail()
	 */
	call_hooks('email_send', $params);

	if($params['sent']) {
		logger('notification: z_mail returns ' . (($params['result']) ? 'success' : 'failure'), LOGGER_DEBUG);
		return $params['result'];
	}

	$fromName = email_header_encode(html_entity_decode($params['fromName'],ENT_QUOTES,'UTF-8'),'UTF-8');
	$messageSubject = email_header_encode(html_entity_decode($params['messageSubject'],ENT_QUOTES,'UTF-8'),'UTF-8');

	$messageHeader =
		$params['additionalMailHeader'] .

		"From: $fromName <{$params['fromEmail']}>" .PHP_EOL .
		"Reply-To: $fromName <{$params['replyTo']}>" . PHP_EOL .
		"Content-Type: text/plain; charset=UTF-8";

	// send the message
	$res = mail(
		$params['toEmail'],								// send to address
		$messageSubject,								// subject
		$params['textVersion'],
		$messageHeader									// message headers
	);
	logger('notification: z_mail returns ' . (($res) ? 'success' : 'failure'), LOGGER_DEBUG);
	return $res;
}


/**
 * @brief Discover the best API path available for redmatrix/hubzilla servers.
 *
 * @param string $host
 * @return string
 */
function probe_api_path($host) {

	$schemes = ['https', 'http' ];
	$paths   = ['/api/z/1.0/version', '/api/red/version' ];

	foreach($schemes as $scheme) {
		foreach($paths as $path) {
			$curpath = $scheme . '://' . $host . $path;
			$x = z_fetch_url($curpath);
			if($x['success'] && ! strpos($x['body'], 'not implemented'))
				return str_replace('version', '', $curpath);
		}
	}

	return '';
}

function service_plink($contact, $guid) {

	$plink = '';

	$m = parse_url($contact['xchan_url']);
	if($m) {
		$url = $m['scheme'] . '://' . $m['host'] . ((isset($m['port']) && intval($m['port'])) ? ':' . intval($m['port']) : '');
	}
	else {
		$url = 'https://' . substr($contact['xchan_addr'],strpos($contact['xchan_addr'],'@')+1);
	}

	$handle = substr($contact['xchan_addr'], 0, strpos($contact['xchan_addr'],'@'));

	$plink = $url . '/channel/' . $handle . '?f=&mid=' . $guid;

	$x = [ 'xchan' => $contact, 'guid' => $guid, 'url' => $url, 'plink' => $plink ];
	/**
	 * @hooks service_plink
	 *   * \e array \b xchan
	 *   * \e string \b guid
	 *   * \e string \b url
	 *   * \e string \b plink will get returned
	 */
	call_hooks('service_plink', $x);

	return $x['plink'];
}


/**
 * @brief
 *
 * @param array $mimeTypes
 * @param string $acceptedTypes by default false will use $_SERVER['HTTP_ACCEPT']
 * @return array|NULL
 */
function getBestSupportedMimeType($mimeTypes = null, $acceptedTypes = false) {
	// Values will be stored in this array
	$AcceptTypes = [];

	if($acceptedTypes === false) {
		$acceptedTypes = ((isset($_SERVER['HTTP_ACCEPT']) && $_SERVER['HTTP_ACCEPT']) ? $_SERVER['HTTP_ACCEPT'] : EMPTY_STR);
	}

	// Accept header is case insensitive, and whitespace isn’t important
	$accept = strtolower(str_replace(' ', '', $acceptedTypes));
	// divide it into parts in the place of a ","
	$accept = explode(',', $accept);
	foreach ($accept as $a) {
		// the default quality is 1.
		$q = 1;
		// check if there is a different quality
		if (strpos($a, ';q=')) {
			// divide "mime/type;q=X" into two parts: "mime/type" i "X"
			list($a, $q) = explode(';q=', $a);
		}
		// mime-type $a is accepted with the quality $q
		// WARNING: $q == 0 means, that mime-type isn’t supported!
		$AcceptTypes[$a] = $q;
	}
	arsort($AcceptTypes);

	// if no parameter was passed, just return parsed data
	if (!$mimeTypes) return $AcceptTypes;

	$mimeTypes = array_map('strtolower', (array)$mimeTypes);

	// let’s check our supported types:
	foreach ($AcceptTypes as $mime => $q) {
		if ($q && in_array($mime, $mimeTypes)) return $mime;
	}

	// no mime-type found
	return null;
}

/**
 * @brief Perform caching for jsonld normaliser.
 *
 * @param string $url
 * @return mixed|boolean|array
 */
function jsonld_document_loader($url) {

	require_once('library/jsonld/jsonld.php');

	$recursion = 0;

	$x = debug_backtrace();
	if($x) {
		foreach($x as $n) {
			if($n['function'] === __FUNCTION__)  {
				$recursion ++;
			}
		}
	}
	if($recursion > 5) {
		logger('jsonld bomb detected at: ' . $url);
		killme();
	}


	$cachepath = 'cache/ldcache';
	if(! is_dir($cachepath))
		os_mkdir($cachepath, STORAGE_DEFAULT_PERMISSIONS, true);

	$filename = $cachepath . '/' . urlencode($url);
	if(file_exists($filename) && filemtime($filename) > time() - (12 * 60 * 60)) {
		return json_decode(file_get_contents($filename));
	}

	$r = jsonld_default_document_loader($url);
	if($r) {
		file_put_contents($filename, json_encode($r));
		return $r;
	}

	logger('not found');
	if(file_exists($filename)) {
		return json_decode(file_get_contents($filename));
	}

	return [];
}


function is_https_request() {

	$https = false;

	if (array_key_exists('HTTPS',$_SERVER) && $_SERVER['HTTPS']) {
		$https = true;
	}
	elseif (array_key_exists('SERVER_PORT',$_SERVER) && intval($_SERVER['SERVER_PORT']) === 443) {
		$https = true;
	}
	elseif (array_key_exists('HTTP_X_FORWARDED_PROTO',$_SERVER) && $_SERVER['HTTP_X_FORWARDED_PROTO'] === 'https') {
		$https = true; // technically this is not true, but pretending it is will allow reverse proxies to work
	}

	return $https;
}

/**
 * @brief Given a URL, return everything after the host portion.
 * example https://foobar.com/gravy?g=5&y=6
 * returns /gravy?g=5&y=6
 * result always returns the leading slash
 */

function get_request_string($url) {

	$a = explode('/',$url,4);
	return '/' . ((count($a) > 3) ? $a[3] : EMPTY_STR);

}