MyShaarli/application/http/HttpUtils.php

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<?php
use Shaarli\Http\Url;
/**
* GET an HTTP URL to retrieve its content
* Uses the cURL library or a fallback method
*
* @param string $url URL to get (http://...)
* @param int $timeout network timeout (in seconds)
* @param int $maxBytes maximum downloaded bytes (default: 4 MiB)
* @param callable|string $curlHeaderFunction Optional callback called during the download of headers
* (CURLOPT_HEADERFUNCTION)
* @param callable|string $curlWriteFunction Optional callback called during the download (cURL CURLOPT_WRITEFUNCTION).
* Can be used to add download conditions on the
* headers (response code, content type, etc.).
*
* @return array HTTP response headers, downloaded content
*
* Output format:
* [0] = associative array containing HTTP response headers
* [1] = URL content (downloaded data)
*
* Example:
* list($headers, $data) = get_http_response('http://sebauvage.net/');
* if (strpos($headers[0], '200 OK') !== false) {
* echo 'Data type: '.htmlspecialchars($headers['Content-Type']);
* } else {
* echo 'There was an error: '.htmlspecialchars($headers[0]);
* }
*
* @see https://secure.php.net/manual/en/ref.curl.php
* @see https://secure.php.net/manual/en/functions.anonymous.php
* @see https://secure.php.net/manual/en/function.preg-split.php
* @see https://secure.php.net/manual/en/function.explode.php
* @see http://stackoverflow.com/q/17641073
* @see http://stackoverflow.com/q/9183178
* @see http://stackoverflow.com/q/1462720
*/
function get_http_response(
$url,
$timeout = 30,
$maxBytes = 4194304,
$curlHeaderFunction = null,
$curlWriteFunction = null
) {
$urlObj = new Url($url);
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$cleanUrl = $urlObj->idnToAscii();
if (!filter_var($cleanUrl, FILTER_VALIDATE_URL) || !$urlObj->isHttp()) {
return array(array(0 => 'Invalid HTTP UrlUtils'), false);
}
$userAgent =
'Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:45.0)'
. ' Gecko/20100101 Firefox/45.0';
$acceptLanguage =
substr(setlocale(LC_COLLATE, 0), 0, 2) . ',en-US;q=0.7,en;q=0.3';
$maxRedirs = 3;
if (!function_exists('curl_init')) {
return get_http_response_fallback(
$cleanUrl,
$timeout,
$maxBytes,
$userAgent,
$acceptLanguage,
$maxRedirs
);
}
$ch = curl_init($cleanUrl);
if ($ch === false) {
return array(array(0 => 'curl_init() error'), false);
}
// General cURL settings
curl_setopt($ch, CURLOPT_AUTOREFERER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
// Default header download if the $curlHeaderFunction is not defined
curl_setopt($ch, CURLOPT_HEADER, !is_callable($curlHeaderFunction));
curl_setopt(
$ch,
CURLOPT_HTTPHEADER,
array('Accept-Language: ' . $acceptLanguage)
);
curl_setopt($ch, CURLOPT_MAXREDIRS, $maxRedirs);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
curl_setopt($ch, CURLOPT_USERAGENT, $userAgent);
// Max download size management
curl_setopt($ch, CURLOPT_BUFFERSIZE, 1024*16);
curl_setopt($ch, CURLOPT_NOPROGRESS, false);
if (is_callable($curlHeaderFunction)) {
curl_setopt($ch, CURLOPT_HEADERFUNCTION, $curlHeaderFunction);
}
if (is_callable($curlWriteFunction)) {
curl_setopt($ch, CURLOPT_WRITEFUNCTION, $curlWriteFunction);
}
curl_setopt(
$ch,
CURLOPT_PROGRESSFUNCTION,
function ($arg0, $arg1, $arg2, $arg3, $arg4) use ($maxBytes) {
$downloaded = $arg2;
// Non-zero return stops downloading
return ($downloaded > $maxBytes) ? 1 : 0;
}
);
$response = curl_exec($ch);
$errorNo = curl_errno($ch);
$errorStr = curl_error($ch);
$headSize = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
curl_close($ch);
if ($response === false) {
if ($errorNo == CURLE_COULDNT_RESOLVE_HOST) {
/*
* Workaround to match fallback method behaviour
* Removing this would require updating
* GetHttpUrlTest::testGetInvalidRemoteUrl()
*/
return array(false, false);
}
return array(array(0 => 'curl_exec() error: ' . $errorStr), false);
}
// Formatting output like the fallback method
$rawHeaders = substr($response, 0, $headSize);
// Keep only headers from latest redirection
$rawHeadersArrayRedirs = explode("\r\n\r\n", trim($rawHeaders));
$rawHeadersLastRedir = end($rawHeadersArrayRedirs);
$content = substr($response, $headSize);
$headers = array();
foreach (preg_split('~[\r\n]+~', $rawHeadersLastRedir) as $line) {
if (empty($line) || ctype_space($line)) {
continue;
}
$splitLine = explode(': ', $line, 2);
if (count($splitLine) > 1) {
$key = $splitLine[0];
$value = $splitLine[1];
if (array_key_exists($key, $headers)) {
if (!is_array($headers[$key])) {
$headers[$key] = array(0 => $headers[$key]);
}
$headers[$key][] = $value;
} else {
$headers[$key] = $value;
}
} else {
$headers[] = $splitLine[0];
}
}
return array($headers, $content);
}
/**
* GET an HTTP URL to retrieve its content (fallback method)
*
* @param string $cleanUrl URL to get (http://... valid and in ASCII form)
* @param int $timeout network timeout (in seconds)
* @param int $maxBytes maximum downloaded bytes
* @param string $userAgent "User-Agent" header
* @param string $acceptLanguage "Accept-Language" header
* @param int $maxRedr maximum amount of redirections followed
*
* @return array HTTP response headers, downloaded content
*
* Output format:
* [0] = associative array containing HTTP response headers
* [1] = URL content (downloaded data)
*
* @see http://php.net/manual/en/function.file-get-contents.php
* @see http://php.net/manual/en/function.stream-context-create.php
* @see http://php.net/manual/en/function.get-headers.php
*/
function get_http_response_fallback(
$cleanUrl,
$timeout,
$maxBytes,
$userAgent,
$acceptLanguage,
$maxRedr
) {
$options = array(
'http' => array(
'method' => 'GET',
'timeout' => $timeout,
'user_agent' => $userAgent,
'header' => "Accept: */*\r\n"
. 'Accept-Language: ' . $acceptLanguage
)
);
stream_context_set_default($options);
list($headers, $finalUrl) = get_redirected_headers($cleanUrl, $maxRedr);
if (! $headers || strpos($headers[0], '200 OK') === false) {
$options['http']['request_fulluri'] = true;
stream_context_set_default($options);
list($headers, $finalUrl) = get_redirected_headers($cleanUrl, $maxRedr);
}
if (! $headers) {
return array($headers, false);
}
try {
// TODO: catch Exception in calling code (thumbnailer)
$context = stream_context_create($options);
$content = file_get_contents($finalUrl, false, $context, -1, $maxBytes);
} catch (Exception $exc) {
return array(array(0 => 'HTTP Error'), $exc->getMessage());
}
return array($headers, $content);
}
/**
* Retrieve HTTP headers, following n redirections (temporary and permanent ones).
*
* @param string $url initial URL to reach.
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* @param int $redirectionLimit max redirection follow.
*
* @return array HTTP headers, or false if it failed.
*/
function get_redirected_headers($url, $redirectionLimit = 3)
{
$headers = get_headers($url, 1);
if (!empty($headers['location']) && empty($headers['Location'])) {
$headers['Location'] = $headers['location'];
}
// Headers found, redirection found, and limit not reached.
if ($redirectionLimit-- > 0
&& !empty($headers)
&& (strpos($headers[0], '301') !== false || strpos($headers[0], '302') !== false)
&& !empty($headers['Location'])) {
$redirection = is_array($headers['Location']) ? end($headers['Location']) : $headers['Location'];
if ($redirection != $url) {
$redirection = getAbsoluteUrl($url, $redirection);
return get_redirected_headers($redirection, $redirectionLimit);
}
}
return array($headers, $url);
}
/**
* Get an absolute URL from a complete one, and another absolute/relative URL.
*
* @param string $originalUrl The original complete URL.
* @param string $newUrl The new one, absolute or relative.
*
* @return string Final URL:
* - $newUrl if it was already an absolute URL.
* - if it was relative, absolute URL from $originalUrl path.
*/
function getAbsoluteUrl($originalUrl, $newUrl)
{
$newScheme = parse_url($newUrl, PHP_URL_SCHEME);
// Already an absolute URL.
if (!empty($newScheme)) {
return $newUrl;
}
$parts = parse_url($originalUrl);
$final = $parts['scheme'] .'://'. $parts['host'];
$final .= (!empty($parts['port'])) ? $parts['port'] : '';
$final .= '/';
if ($newUrl[0] != '/') {
$final .= substr(ltrim($parts['path'], '/'), 0, strrpos($parts['path'], '/'));
}
$final .= ltrim($newUrl, '/');
return $final;
}
/**
* Returns the server's base URL: scheme://domain.tld[:port]
*
* @param array $server the $_SERVER array
*
* @return string the server's base URL
*
* @see http://www.ietf.org/rfc/rfc7239.txt
* @see http://www.ietf.org/rfc/rfc6648.txt
* @see http://stackoverflow.com/a/3561399
* @see http://stackoverflow.com/q/452375
*/
function server_url($server)
{
$scheme = 'http';
$port = '';
// Shaarli is served behind a proxy
if (isset($server['HTTP_X_FORWARDED_PROTO'])) {
// Keep forwarded scheme
if (strpos($server['HTTP_X_FORWARDED_PROTO'], ',') !== false) {
$schemes = explode(',', $server['HTTP_X_FORWARDED_PROTO']);
$scheme = trim($schemes[0]);
} else {
$scheme = $server['HTTP_X_FORWARDED_PROTO'];
}
if (isset($server['HTTP_X_FORWARDED_PORT'])) {
// Keep forwarded port
if (strpos($server['HTTP_X_FORWARDED_PORT'], ',') !== false) {
$ports = explode(',', $server['HTTP_X_FORWARDED_PORT']);
$port = trim($ports[0]);
} else {
$port = $server['HTTP_X_FORWARDED_PORT'];
}
// This is a workaround for proxies that don't forward the scheme properly.
// Connecting over port 443 has to be in HTTPS.
// See https://github.com/shaarli/Shaarli/issues/1022
if ($port == '443') {
$scheme = 'https';
}
if (($scheme == 'http' && $port != '80')
|| ($scheme == 'https' && $port != '443')
) {
$port = ':' . $port;
} else {
$port = '';
}
}
if (isset($server['HTTP_X_FORWARDED_HOST'])) {
// Keep forwarded host
if (strpos($server['HTTP_X_FORWARDED_HOST'], ',') !== false) {
$hosts = explode(',', $server['HTTP_X_FORWARDED_HOST']);
$host = trim($hosts[0]);
} else {
$host = $server['HTTP_X_FORWARDED_HOST'];
}
} else {
$host = $server['SERVER_NAME'];
}
return $scheme.'://'.$host.$port;
}
// SSL detection
if ((! empty($server['HTTPS']) && strtolower($server['HTTPS']) == 'on')
|| (isset($server['SERVER_PORT']) && $server['SERVER_PORT'] == '443')) {
$scheme = 'https';
}
// Do not append standard port values
if (($scheme == 'http' && $server['SERVER_PORT'] != '80')
|| ($scheme == 'https' && $server['SERVER_PORT'] != '443')) {
$port = ':'.$server['SERVER_PORT'];
}
return $scheme.'://'.$server['SERVER_NAME'].$port;
}
/**
* Returns the absolute URL of the current script, without the query
*
* If the resource is "index.php", then it is removed (for better-looking URLs)
*
* @param array $server the $_SERVER array
*
* @return string the absolute URL of the current script, without the query
*/
function index_url($server)
{
if (defined('SHAARLI_ROOT_URL') && null !== SHAARLI_ROOT_URL) {
return rtrim(SHAARLI_ROOT_URL, '/') . '/';
}
$scriptname = !empty($server['SCRIPT_NAME']) ? $server['SCRIPT_NAME'] : '/';
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if (endsWith($scriptname, 'index.php')) {
$scriptname = substr($scriptname, 0, -9);
}
return server_url($server) . $scriptname;
}
/**
* Returns the absolute URL of the current script, with current route and query
*
* If the resource is "index.php", then it is removed (for better-looking URLs)
*
* @param array $server the $_SERVER array
*
* @return string the absolute URL of the current script, with the query
*/
function page_url($server)
{
$scriptname = $server['SCRIPT_NAME'] ?? '';
if (endsWith($scriptname, 'index.php')) {
$scriptname = substr($scriptname, 0, -9);
}
$route = preg_replace('@^' . $scriptname . '@', '', $server['REQUEST_URI'] ?? '');
if (! empty($server['QUERY_STRING'])) {
return index_url($server) . $route . '?' . $server['QUERY_STRING'];
}
return index_url($server) . $route;
}
/**
* Retrieve the initial IP forwarded by the reverse proxy.
*
* Inspired from: https://github.com/zendframework/zend-http/blob/master/src/PhpEnvironment/RemoteAddress.php
*
* @param array $server $_SERVER array which contains HTTP headers.
* @param array $trustedIps List of trusted IP from the configuration.
*
* @return string|bool The forwarded IP, or false if none could be extracted.
*/
function getIpAddressFromProxy($server, $trustedIps)
{
$forwardedIpHeader = 'HTTP_X_FORWARDED_FOR';
if (empty($server[$forwardedIpHeader])) {
return false;
}
$ips = preg_split('/\s*,\s*/', $server[$forwardedIpHeader]);
$ips = array_diff($ips, $trustedIps);
if (empty($ips)) {
return false;
}
return array_pop($ips);
}
/**
* Return an identifier based on the advertised client IP address(es)
*
* This aims at preventing session hijacking from users behind the same proxy
* by relying on HTTP headers.
*
* See:
* - https://secure.php.net/manual/en/reserved.variables.server.php
* - https://stackoverflow.com/questions/3003145/how-to-get-the-client-ip-address-in-php
* - https://stackoverflow.com/questions/12233406/preventing-session-hijacking
* - https://stackoverflow.com/questions/21354859/trusting-x-forwarded-for-to-identify-a-visitor
*
* @param array $server The $_SERVER array
*
* @return string An identifier based on client IP address information
*/
function client_ip_id($server)
{
$ip = $server['REMOTE_ADDR'];
if (isset($server['HTTP_X_FORWARDED_FOR'])) {
$ip = $ip . '_' . $server['HTTP_X_FORWARDED_FOR'];
}
if (isset($server['HTTP_CLIENT_IP'])) {
$ip = $ip . '_' . $server['HTTP_CLIENT_IP'];
}
return $ip;
}
/**
* Returns true if Shaarli's currently browsed in HTTPS.
* Supports reverse proxies (if the headers are correctly set).
*
* @param array $server $_SERVER.
*
* @return bool true if HTTPS, false otherwise.
*/
function is_https($server)
{
if (isset($server['HTTP_X_FORWARDED_PORT'])) {
// Keep forwarded port
if (strpos($server['HTTP_X_FORWARDED_PORT'], ',') !== false) {
$ports = explode(',', $server['HTTP_X_FORWARDED_PORT']);
$port = trim($ports[0]);
} else {
$port = $server['HTTP_X_FORWARDED_PORT'];
}
if ($port == '443') {
return true;
}
}
return ! empty($server['HTTPS']);
}
/**
* Get cURL callback function for CURLOPT_WRITEFUNCTION
*
* @param string $charset to extract from the downloaded page (reference)
* @param string $curlGetInfo Optionally overrides curl_getinfo function
*
* @return Closure
*/
function get_curl_header_callback(
&$charset,
$curlGetInfo = 'curl_getinfo'
) {
$isRedirected = false;
return function ($ch, $data) use ($curlGetInfo, &$charset, &$isRedirected) {
$responseCode = $curlGetInfo($ch, CURLINFO_RESPONSE_CODE);
$chunkLength = strlen($data);
if (!empty($responseCode) && in_array($responseCode, [301, 302])) {
$isRedirected = true;
return $chunkLength;
}
if (!empty($responseCode) && $responseCode !== 200) {
return false;
}
// After a redirection, the content type will keep the previous request value
// until it finds the next content-type header.
if (! $isRedirected || strpos(strtolower($data), 'content-type') !== false) {
$contentType = $curlGetInfo($ch, CURLINFO_CONTENT_TYPE);
}
if (!empty($contentType) && strpos($contentType, 'text/html') === false) {
return false;
}
if (!empty($contentType) && empty($charset)) {
$charset = header_extract_charset($contentType);
}
return $chunkLength;
};
}
/**
* Get cURL callback function for CURLOPT_WRITEFUNCTION
*
* @param string $charset to extract from the downloaded page (reference)
* @param string $title to extract from the downloaded page (reference)
* @param string $description to extract from the downloaded page (reference)
* @param string $keywords to extract from the downloaded page (reference)
* @param bool $retrieveDescription Automatically tries to retrieve description and keywords from HTML content
* @param string $curlGetInfo Optionally overrides curl_getinfo function
*
* @return Closure
*/
function get_curl_download_callback(
&$charset,
&$title,
&$description,
&$keywords,
$retrieveDescription,
$tagsSeparator
) {
$currentChunk = 0;
$foundChunk = null;
/**
* cURL callback function for CURLOPT_WRITEFUNCTION (called during the download).
*
* While downloading the remote page, we check that the HTTP code is 200 and content type is 'html/text'
* Then we extract the title and the charset and stop the download when it's done.
*
* @param resource $ch cURL resource
* @param string $data chunk of data being downloaded
*
* @return int|bool length of $data or false if we need to stop the download
*/
return function ($ch, $data) use (
$retrieveDescription,
$tagsSeparator,
&$charset,
&$title,
&$description,
&$keywords,
&$currentChunk,
&$foundChunk
) {
$chunkLength = strlen($data);
$currentChunk++;
if (empty($charset)) {
$charset = html_extract_charset($data);
}
if (empty($title)) {
$title = html_extract_title($data);
$foundChunk = ! empty($title) ? $currentChunk : $foundChunk;
}
if (empty($title)) {
$title = html_extract_tag('title', $data);
$foundChunk = ! empty($title) ? $currentChunk : $foundChunk;
}
if ($retrieveDescription && empty($description)) {
$description = html_extract_tag('description', $data);
$foundChunk = ! empty($description) ? $currentChunk : $foundChunk;
}
if ($retrieveDescription && empty($keywords)) {
$keywords = html_extract_tag('keywords', $data);
if (! empty($keywords)) {
$foundChunk = $currentChunk;
// Keywords use the format tag1, tag2 multiple words, tag
// So we split the result with `,`, then if a tag contains the separator we replace it by `-`.
$keywords = tags_array2str(array_map(function(string $keyword) use ($tagsSeparator): string {
return tags_array2str(tags_str2array($keyword, $tagsSeparator), '-');
}, tags_str2array($keywords, ',')), $tagsSeparator);
}
}
// We got everything we want, stop the download.
// If we already found either the title, description or keywords,
// it's highly unlikely that we'll found the other metas further than
// in the same chunk of data or the next one. So we also stop the download after that.
if ((!empty($responseCode) && !empty($contentType) && !empty($charset)) && $foundChunk !== null
&& (! $retrieveDescription
|| $foundChunk < $currentChunk
|| (!empty($title) && !empty($description) && !empty($keywords))
)
) {
return false;
}
return $chunkLength;
};
}