|null */ function splitHeader(HttpMessage $message, string $headerName): ?array { $header = \implode(',', $message->getHeaderArray($headerName)); if ($header === '') { return []; } $positions = []; $withinQuotes = false; $headerLength = \strlen($header); for ($i = 0; $i < $headerLength; ++$i) { match ($header[$i]) { '\\' => ++$i, // Skip next character '"' => $withinQuotes = !$withinQuotes, ',' => $withinQuotes ? null : $positions[] = $i, default => null, }; } if ($withinQuotes) { return null; } if (!$positions) { return [\trim($header)]; } $offset = 0; $headers = []; foreach ($positions as $position) { $headers[] = \substr($header, $offset, $position - $offset); $offset = $position + 1; } $headers[] = \substr($header, $offset); return \array_map(\trim(...), $headers); } /** * Parses a list of key-value pairs from each comma-separated header value. Returns null if a syntax error is * encountered. * * For example, the following header * `Forwarded: for="172.18.0.1";proto=https, for="172.25.0.1";proto=http` * would be parsed to the array * `[['for' => '172.18.0.1', 'proto' => 'https'], ['for' => '172.25.0.1', 'proto' => 'http']]` * * @param non-empty-string $headerName * * @return list>|null */ function parseMultipleHeaderFields(HttpMessage $message, string $headerName): ?array { $headers = splitHeader($message, $headerName); if ($headers === null) { return null; } $maps = []; foreach ($headers as $header) { $map = parseSingleHeaderFields($header); if ($map === null) { return null; } $maps[] = $map; } return $maps; } /** * Parse a single header into key-value pairs. * * @see https://tools.ietf.org/html/rfc7230#section-3.2.6 * * @return array|null */ function parseSingleHeaderFields(string $header): ?array { \preg_match_all( '((?:^|;\s*)([^=]+)(?:=(?:"((?:[^\\\\"]|\\\\\\\\|\\\\")*)"|([^";]+)))?\s*)', $header, $matches, \PREG_SET_ORDER, ); $totalMatchedLength = 0; $map = []; foreach ($matches as $match) { $totalMatchedLength += \strlen($match[0]); $key = \trim(\strtolower($match[1])); $value = $match[3] ?? $match[2] ?? ''; if (($match[2] ?? '') !== '') { // decode escaped characters $value = (string) \preg_replace('/\\\\(.)/', '\1', $match[2]); } \assert($key !== ''); $map[$key] = $value; } if ($totalMatchedLength !== \strlen($header)) { return null; // parse error } return $map; } /** * Parses a list of tokens from each comma-separated header value. Returns null if a syntax error is * encountered. Use {@see parseMultipleHeaderFields()} for headers with key-value pairs. * * @link https://datatracker.ietf.org/doc/html/rfc7230#section-3.2.6 * * @return list|null */ function parseHeaderTokens(HttpMessage $message, string $headerName): ?array { $combinedHeader = \implode(",", $message->getHeaderArray($headerName)); if (\preg_match('([^!#$%&\'*+\-.^_`|~0-9A-Za-z, ])', $combinedHeader)) { return null; } $elements = \explode(",", $combinedHeader); $normalizedElements = \array_map(fn ($element) => \strtolower(\trim($element)), $elements); return \array_values(\array_filter($normalizedElements, fn ($element) => $element !== '')); } /** * Format timestamp in seconds as an HTTP date header. * * @param int|null $timestamp Timestamp to format, current time if `null`. * * @return string Formatted date header value. */ function formatDateHeader(?int $timestamp = null): string { static $cachedTimestamp, $cachedFormattedDate; $timestamp = $timestamp ?? \time(); if ($cachedTimestamp === $timestamp) { return $cachedFormattedDate; } return $cachedFormattedDate = \gmdate("D, d M Y H:i:s", $cachedTimestamp = $timestamp) . " GMT"; } /** * Convert the output of {@see Rfc7230::parseHeaderPairs()} or {@see HttpMessage::getHeaderPairs()} into the structure * returned by {@see Rfc7230::parseHeaders()} or {@see HttpMessage::getHeaders()}. * * @param list $pairs * * @return array> */ function mapHeaderPairs(array $pairs): array { $headers = []; foreach ($pairs as $header) { /** @psalm-suppress RedundantCondition */ \assert( \count($header) === 2 && \array_is_list($header) && \is_string($header[0]) && \is_string($header[1]) ); $headers[Internal\HEADER_LOWERCASE_MAP[$header[0]] ?? \strtolower($header[0])][] = $header[1]; } return $headers; }