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Diffstat (limited to 'classes/UrlHelper.php')
| -rw-r--r-- | classes/UrlHelper.php | 656 |
1 files changed, 656 insertions, 0 deletions
diff --git a/classes/UrlHelper.php b/classes/UrlHelper.php new file mode 100644 index 000000000..dbbde55e6 --- /dev/null +++ b/classes/UrlHelper.php @@ -0,0 +1,656 @@ +<?php +class UrlHelper { + const EXTRA_HREF_SCHEMES = [ + "magnet", + "mailto", + "tel" + ]; + + const EXTRA_SCHEMES_BY_CONTENT_TYPE = [ + "application/x-bittorrent" => [ "magnet" ], + ]; + + static string $fetch_last_error; + static int $fetch_last_error_code; + static string $fetch_last_error_content; + static string $fetch_last_content_type; + static string $fetch_last_modified; + static string $fetch_effective_url; + static string $fetch_effective_ip_addr; + static bool $fetch_curl_used; + + /** + * @param array<string, string|int> $parts + */ + static function build_url(array $parts): string { + $tmp = $parts['scheme'] . "://" . $parts['host']; + + if (isset($parts['path'])) $tmp .= $parts['path']; + if (isset($parts['query'])) $tmp .= '?' . $parts['query']; + if (isset($parts['fragment'])) $tmp .= '#' . $parts['fragment']; + + return $tmp; + } + + /** + * Converts a (possibly) relative URL to a absolute one, using provided base URL. + * Provides some exceptions for additional schemes like data: if called with owning element/attribute. + * + * @param string $base_url Base URL (i.e. from where the document is) + * @param string $rel_url Possibly relative URL in the document + * @param string $owner_element Owner element tag name (i.e. "a") (optional) + * @param string $owner_attribute Owner attribute (i.e. "href") (optional) + * @param string $content_type URL content type as specified by enclosures, etc. + * + * @return false|string Absolute URL or false on failure (either during URL parsing or validation) + */ + public static function rewrite_relative($base_url, + $rel_url, + string $owner_element = "", + string $owner_attribute = "", + string $content_type = "") { + + $rel_parts = parse_url($rel_url); + + if (!$rel_url) return $base_url; + + /** + * If parse_url failed to parse $rel_url return false to match the current "invalid thing" behavior + * of UrlHelper::validate(). + * + * TODO: There are many places where a string return value is assumed. We should either update those + * to account for the possibility of failure, or look into updating this function's return values. + */ + if ($rel_parts === false) { + return false; + } + + if (!empty($rel_parts['host']) && !empty($rel_parts['scheme'])) { + return self::validate($rel_url); + + // protocol-relative URL (rare but they exist) + } else if (strpos($rel_url, "//") === 0) { + return self::validate("https:" . $rel_url); + // allow some extra schemes for A href + } else if (in_array($rel_parts["scheme"] ?? "", self::EXTRA_HREF_SCHEMES, true) && + $owner_element == "a" && + $owner_attribute == "href") { + return $rel_url; + // allow some extra schemes for links with feed-specified content type i.e. enclosures + } else if ($content_type && + isset(self::EXTRA_SCHEMES_BY_CONTENT_TYPE[$content_type]) && + in_array($rel_parts["scheme"], self::EXTRA_SCHEMES_BY_CONTENT_TYPE[$content_type])) { + return $rel_url; + // allow limited subset of inline base64-encoded images for IMG elements + } else if (($rel_parts["scheme"] ?? "") == "data" && + preg_match('%^image/(webp|gif|jpg|png|svg);base64,%', $rel_parts["path"]) && + $owner_element == "img" && + $owner_attribute == "src") { + return $rel_url; + } else { + $base_parts = parse_url($base_url); + + $rel_parts['host'] = $base_parts['host'] ?? ""; + $rel_parts['scheme'] = $base_parts['scheme'] ?? ""; + + if ($rel_parts['path'] ?? "") { + + // we append dirname() of base path to relative URL path as per RFC 3986 section 5.2.2 + $base_path = with_trailing_slash(dirname($base_parts['path'] ?? "")); + + // 1. absolute relative path (/test.html) = no-op, proceed as is + + // 2. dotslash relative URI (./test.html) - strip "./", append base path + if (strpos($rel_parts['path'], './') === 0) { + $rel_parts['path'] = $base_path . substr($rel_parts['path'], 2); + // 3. anything else relative (test.html) - append dirname() of base path + } else if (strpos($rel_parts['path'], '/') !== 0) { + $rel_parts['path'] = $base_path . $rel_parts['path']; + } + + //$rel_parts['path'] = str_replace("/./", "/", $rel_parts['path']); + //$rel_parts['path'] = str_replace("//", "/", $rel_parts['path']); + } + + return self::validate(self::build_url($rel_parts)); + } + } + + /** extended filtering involves validation for safe ports and loopback + * @return false|string false if something went wrong, otherwise the URL string + */ + static function validate(string $url, bool $extended_filtering = false) { + + $url = clean($url); + + # fix protocol-relative URLs + if (strpos($url, "//") === 0) + $url = "https:" . $url; + + $tokens = parse_url($url); + + // this isn't really necessary because filter_var(... FILTER_VALIDATE_URL) requires host and scheme + // as per https://php.watch/versions/7.3/filter-var-flag-deprecation but it might save time + if (empty($tokens['host'])) + return false; + + if (!in_array(strtolower($tokens['scheme']), ['http', 'https'])) + return false; + + //convert IDNA hostname to punycode if possible + if (function_exists("idn_to_ascii")) { + if (mb_detect_encoding($tokens['host']) != 'ASCII') { + if (defined('IDNA_NONTRANSITIONAL_TO_ASCII') && defined('INTL_IDNA_VARIANT_UTS46')) { + $tokens['host'] = idn_to_ascii($tokens['host'], IDNA_NONTRANSITIONAL_TO_ASCII, INTL_IDNA_VARIANT_UTS46); + } else { + $tokens['host'] = idn_to_ascii($tokens['host']); + } + + // if `idn_to_ascii` failed + if ($tokens['host'] === false) { + return false; + } + } + } + + // separate set of tokens with urlencoded 'path' because filter_var() rightfully fails on non-latin characters + // (used for validation only, we actually request the original URL, in case of urlencode breaking it) + $tokens_filter_var = $tokens; + + if ($tokens['path'] ?? false) { + $tokens_filter_var['path'] = implode("/", + array_map("rawurlencode", + array_map("rawurldecode", + explode("/", $tokens['path'])))); + } + + $url = self::build_url($tokens); + $url_filter_var = self::build_url($tokens_filter_var); + + if (filter_var($url_filter_var, FILTER_VALIDATE_URL) === false) + return false; + + if ($extended_filtering) { + if (!in_array($tokens['port'] ?? '', [80, 443, ''])) + return false; + + if (strtolower($tokens['host']) == 'localhost' || $tokens['host'] == '::1' || strpos($tokens['host'], '127.') === 0) + return false; + } + + return $url; + } + + /** + * @return false|string + */ + static function resolve_redirects(string $url, int $timeout, int $nest = 0) { + $span = Tracer::start(__METHOD__); + $span->setAttribute('func.args', json_encode(func_get_args())); + + // too many redirects + if ($nest > 10) { + $span->setAttribute('error', 'too many redirects'); + $span->end(); + return false; + } + + $context_options = array( + 'http' => array( + 'header' => array( + 'Connection: close' + ), + 'method' => 'HEAD', + 'timeout' => $timeout, + 'protocol_version'=> 1.1) + ); + + if (Config::get(Config::HTTP_PROXY)) { + $context_options['http']['request_fulluri'] = true; + $context_options['http']['proxy'] = Config::get(Config::HTTP_PROXY); + } + + $context = stream_context_create($context_options); + + // PHP 8 changed the second param from int to bool, but we still support PHP >= 7.4.0 + // @phpstan-ignore-next-line + $headers = get_headers($url, 0, $context); + + if (is_array($headers)) { + $headers = array_reverse($headers); // last one is the correct one + + foreach($headers as $header) { + if (stripos($header, 'Location:') === 0) { + $url = self::rewrite_relative($url, trim(substr($header, strlen('Location:')))); + + return self::resolve_redirects($url, $timeout, $nest + 1); + } + } + + $span->end(); + return $url; + } + + $span->setAttribute('error', 'request failed'); + $span->end(); + // request failed? + return false; + } + + /** + * @param array<string, bool|int|string>|string $options + * @return false|string false if something went wrong, otherwise string contents + */ + // TODO: max_size currently only works for CURL transfers + // TODO: multiple-argument way is deprecated, first parameter is a hash now + public static function fetch($options /* previously: 0: $url , 1: $type = false, 2: $login = false, 3: $pass = false, + 4: $post_query = false, 5: $timeout = false, 6: $timestamp = 0, 7: $useragent = false*/) { + + self::$fetch_last_error = ""; + self::$fetch_last_error_code = -1; + self::$fetch_last_error_content = ""; + self::$fetch_last_content_type = ""; + self::$fetch_curl_used = false; + self::$fetch_last_modified = ""; + self::$fetch_effective_url = ""; + self::$fetch_effective_ip_addr = ""; + + if (!is_array($options)) { + + // falling back on compatibility shim + $option_names = [ "url", "type", "login", "pass", "post_query", "timeout", "last_modified", "useragent" ]; + $tmp = []; + + for ($i = 0; $i < func_num_args(); $i++) { + $tmp[$option_names[$i]] = func_get_arg($i); + } + + $options = $tmp; + + /*$options = array( + "url" => func_get_arg(0), + "type" => @func_get_arg(1), + "login" => @func_get_arg(2), + "pass" => @func_get_arg(3), + "post_query" => @func_get_arg(4), + "timeout" => @func_get_arg(5), + "timestamp" => @func_get_arg(6), + "useragent" => @func_get_arg(7) + ); */ + } + $url = $options["url"]; + + $span = Tracer::start(__METHOD__); + $span->setAttribute('func.args', json_encode(func_get_args())); + + $type = isset($options["type"]) ? $options["type"] : false; + $login = isset($options["login"]) ? $options["login"] : false; + $pass = isset($options["pass"]) ? $options["pass"] : false; + $post_query = isset($options["post_query"]) ? $options["post_query"] : false; + $timeout = isset($options["timeout"]) ? $options["timeout"] : false; + $last_modified = isset($options["last_modified"]) ? $options["last_modified"] : ""; + $useragent = isset($options["useragent"]) ? $options["useragent"] : false; + $followlocation = isset($options["followlocation"]) ? $options["followlocation"] : true; + $max_size = isset($options["max_size"]) ? $options["max_size"] : Config::get(Config::MAX_DOWNLOAD_FILE_SIZE); // in bytes + $http_accept = isset($options["http_accept"]) ? $options["http_accept"] : false; + $http_referrer = isset($options["http_referrer"]) ? $options["http_referrer"] : false; + + $url = ltrim($url, ' '); + $url = str_replace(' ', '%20', $url); + + Debug::log("[UrlHelper] fetching: $url", Debug::LOG_EXTENDED); + + $url = self::validate($url, true); + + if (!$url) { + self::$fetch_last_error = "Requested URL failed extended validation."; + + $span->setAttribute('error', self::$fetch_last_error); + $span->end(); + return false; + } + + $url_host = parse_url($url, PHP_URL_HOST); + $ip_addr = gethostbyname($url_host); + + if (!$ip_addr || strpos($ip_addr, "127.") === 0) { + self::$fetch_last_error = "URL hostname failed to resolve or resolved to a loopback address ($ip_addr)"; + + $span->setAttribute('error', self::$fetch_last_error); + $span->end(); + return false; + } + + if (function_exists('curl_init') && !ini_get("open_basedir")) { + + self::$fetch_curl_used = true; + + $ch = curl_init($url); + + if (!$ch) { + self::$fetch_last_error = "curl_init() failed"; + $span->setAttribute('error', self::$fetch_last_error); + $span->end(); + return false; + } + + $curl_http_headers = []; + + if ($last_modified && !$post_query) + array_push($curl_http_headers, "If-Modified-Since: $last_modified"); + + if ($http_accept) + array_push($curl_http_headers, "Accept: " . $http_accept); + + if (count($curl_http_headers) > 0) + curl_setopt($ch, CURLOPT_HTTPHEADER, $curl_http_headers); + + curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout ? $timeout : Config::get(Config::FILE_FETCH_CONNECT_TIMEOUT)); + curl_setopt($ch, CURLOPT_TIMEOUT, $timeout ? $timeout : Config::get(Config::FILE_FETCH_TIMEOUT)); + curl_setopt($ch, CURLOPT_FOLLOWLOCATION, $followlocation); + curl_setopt($ch, CURLOPT_MAXREDIRS, 20); + curl_setopt($ch, CURLOPT_BINARYTRANSFER, true); + curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); + curl_setopt($ch, CURLOPT_HEADER, true); + curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC); + curl_setopt($ch, CURLOPT_USERAGENT, $useragent ? $useragent : Config::get_user_agent()); + curl_setopt($ch, CURLOPT_ENCODING, ""); + curl_setopt($ch, CURLOPT_COOKIEJAR, "/dev/null"); + + if ($http_referrer) + curl_setopt($ch, CURLOPT_REFERER, $http_referrer); + + if ($max_size) { + curl_setopt($ch, CURLOPT_NOPROGRESS, false); + curl_setopt($ch, CURLOPT_BUFFERSIZE, 16384); // needed to get 5 arguments in progress function? + + // holy shit closures in php + // download & upload are *expected* sizes respectively, could be zero + curl_setopt($ch, CURLOPT_PROGRESSFUNCTION, function($curl_handle, $download_size, $downloaded, $upload_size, $uploaded) use(&$max_size, $url) { + //Debug::log("[curl progressfunction] $downloaded $max_size", Debug::$LOG_EXTENDED); + + if ($downloaded > $max_size) { + Debug::log("[UrlHelper] fetch error: curl reached max size of $max_size bytes downloading $url, aborting.", Debug::LOG_VERBOSE); + return 1; + } + + return 0; + }); + + } + + if (Config::get(Config::HTTP_PROXY)) { + curl_setopt($ch, CURLOPT_PROXY, Config::get(Config::HTTP_PROXY)); + } + + if ($post_query) { + curl_setopt($ch, CURLOPT_POST, true); + curl_setopt($ch, CURLOPT_POSTFIELDS, $post_query); + } + + if ($login && $pass) + curl_setopt($ch, CURLOPT_USERPWD, "$login:$pass"); + + $ret = @curl_exec($ch); + $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE); + + // CURLAUTH_BASIC didn't work, let's retry with CURLAUTH_ANY in case it's actually something + // unusual like NTLM... + if ($http_code == 403 && $login && $pass) { + curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_ANY); + + $ret = @curl_exec($ch); + } + + if (curl_errno($ch) === 23 || curl_errno($ch) === 61) { + curl_setopt($ch, CURLOPT_ENCODING, 'none'); + $ret = @curl_exec($ch); + } + + $headers_length = curl_getinfo($ch, CURLINFO_HEADER_SIZE); + $headers = explode("\r\n", substr($ret, 0, $headers_length)); + $contents = substr($ret, $headers_length); + + foreach ($headers as $header) { + if (strstr($header, ": ") !== false) { + list ($key, $value) = explode(": ", $header); + + if (strtolower($key) == "last-modified") { + self::$fetch_last_modified = $value; + } + } + + if (substr(strtolower($header), 0, 7) == 'http/1.') { + self::$fetch_last_error_code = (int) substr($header, 9, 3); + self::$fetch_last_error = $header; + } + } + + $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE); + self::$fetch_last_content_type = curl_getinfo($ch, CURLINFO_CONTENT_TYPE); + + self::$fetch_effective_url = curl_getinfo($ch, CURLINFO_EFFECTIVE_URL); + + if (!self::validate(self::$fetch_effective_url, true)) { + self::$fetch_last_error = "URL received after redirection failed extended validation."; + + $span->setAttribute('error', self::$fetch_last_error); + $span->end(); + return false; + } + + self::$fetch_effective_ip_addr = gethostbyname(parse_url(self::$fetch_effective_url, PHP_URL_HOST)); + + if (!self::$fetch_effective_ip_addr || strpos(self::$fetch_effective_ip_addr, "127.") === 0) { + self::$fetch_last_error = "URL hostname received after redirection failed to resolve or resolved to a loopback address (".self::$fetch_effective_ip_addr.")"; + + $span->setAttribute('error', self::$fetch_last_error); + $span->end(); + return false; + } + + self::$fetch_last_error_code = $http_code; + + if ($http_code != 200 || $type && strpos(self::$fetch_last_content_type, "$type") === false) { + + if (curl_errno($ch) != 0) { + self::$fetch_last_error .= "; " . curl_errno($ch) . " " . curl_error($ch); + } else { + self::$fetch_last_error = "HTTP Code: $http_code "; + } + + self::$fetch_last_error_content = $contents; + curl_close($ch); + + $span->setAttribute('error', self::$fetch_last_error); + $span->end(); + return false; + } + + if (!$contents) { + if (curl_errno($ch) === 0) { + self::$fetch_last_error = 'Successful response, but no content was received.'; + } else { + self::$fetch_last_error = curl_errno($ch) . " " . curl_error($ch); + } + curl_close($ch); + + $span->setAttribute('error', self::$fetch_last_error); + $span->end(); + return false; + } + + curl_close($ch); + + $is_gzipped = RSSUtils::is_gzipped($contents); + + if ($is_gzipped && is_string($contents)) { + $tmp = @gzdecode($contents); + + if ($tmp) $contents = $tmp; + } + + $span->end(); + + return $contents; + } else { + + self::$fetch_curl_used = false; + + if ($login && $pass){ + $url_parts = array(); + + preg_match("/(^[^:]*):\/\/(.*)/", $url, $url_parts); + + $pass = urlencode($pass); + + if ($url_parts[1] && $url_parts[2]) { + $url = $url_parts[1] . "://$login:$pass@" . $url_parts[2]; + } + } + + // TODO: should this support POST requests or not? idk + + $context_options = array( + 'http' => array( + 'header' => array( + 'Connection: close' + ), + 'method' => 'GET', + 'ignore_errors' => true, + 'timeout' => $timeout ? $timeout : Config::get(Config::FILE_FETCH_TIMEOUT), + 'protocol_version'=> 1.1) + ); + + if (!$post_query && $last_modified) + array_push($context_options['http']['header'], "If-Modified-Since: $last_modified"); + + if ($http_accept) + array_push($context_options['http']['header'], "Accept: $http_accept"); + + if ($http_referrer) + array_push($context_options['http']['header'], "Referer: $http_referrer"); + + if (Config::get(Config::HTTP_PROXY)) { + $context_options['http']['request_fulluri'] = true; + $context_options['http']['proxy'] = Config::get(Config::HTTP_PROXY); + } + + $context = stream_context_create($context_options); + + $old_error = error_get_last(); + + self::$fetch_effective_url = self::resolve_redirects($url, $timeout ? $timeout : Config::get(Config::FILE_FETCH_CONNECT_TIMEOUT)); + + if (!self::validate(self::$fetch_effective_url, true)) { + self::$fetch_last_error = "URL received after redirection failed extended validation."; + + $span->setAttribute('error', self::$fetch_last_error); + $span->end(); + return false; + } + + self::$fetch_effective_ip_addr = gethostbyname(parse_url(self::$fetch_effective_url, PHP_URL_HOST)); + + if (!self::$fetch_effective_ip_addr || strpos(self::$fetch_effective_ip_addr, "127.") === 0) { + self::$fetch_last_error = "URL hostname received after redirection failed to resolve or resolved to a loopback address (".self::$fetch_effective_ip_addr.")"; + + $span->setAttribute('error', self::$fetch_last_error); + $span->end(); + return false; + } + + $data = @file_get_contents($url, false, $context); + + if ($data === false) { + self::$fetch_last_error = "'file_get_contents' failed."; + + $span->setAttribute('error', self::$fetch_last_error); + $span->end(); + return false; + } + + foreach ($http_response_header as $header) { + if (strstr($header, ": ") !== false) { + list ($key, $value) = explode(": ", $header); + + $key = strtolower($key); + + if ($key == 'content-type') { + self::$fetch_last_content_type = $value; + // don't abort here b/c there might be more than one + // e.g. if we were being redirected -- last one is the right one + } else if ($key == 'last-modified') { + self::$fetch_last_modified = $value; + } else if ($key == 'location') { + self::$fetch_effective_url = $value; + } + } + + if (substr(strtolower($header), 0, 7) == 'http/1.') { + self::$fetch_last_error_code = (int) substr($header, 9, 3); + self::$fetch_last_error = $header; + } + } + + if (self::$fetch_last_error_code != 200) { + $error = error_get_last(); + + if (($error['message'] ?? '') != ($old_error['message'] ?? '')) { + self::$fetch_last_error .= "; " . $error["message"]; + } + + self::$fetch_last_error_content = $data; + + $span->setAttribute('error', self::$fetch_last_error); + $span->end(); + return false; + } + + if ($data) { + $is_gzipped = RSSUtils::is_gzipped($data); + + if ($is_gzipped) { + $tmp = @gzdecode($data); + + if ($tmp) $data = $tmp; + } + + $span->end(); + return $data; + } else { + self::$fetch_last_error = 'Successful response, but no content was received.'; + + $span->setAttribute('error', self::$fetch_last_error); + $span->end(); + return false; + } + } + } + + /** + * @return false|string false if the provided URL didn't match expected patterns, otherwise the video ID string + */ + public static function url_to_youtube_vid(string $url) { + $url = str_replace("youtube.com", "youtube-nocookie.com", $url); + + $regexps = [ + "/\/\/www\.youtube-nocookie\.com\/v\/([\w-]+)/", + "/\/\/www\.youtube-nocookie\.com\/embed\/([\w-]+)/", + "/\/\/www\.youtube-nocookie\.com\/watch?v=([\w-]+)/", + "/\/\/youtu.be\/([\w-]+)/", + ]; + + foreach ($regexps as $re) { + $matches = []; + + if (preg_match($re, $url, $matches)) { + return $matches[1]; + } + } + + return false; + } + + +} |