defaultOptions = $defaultOptions; $this->randomGenerator = $randomGenerator ?: new Util\RandomGenerator(); $this->initUserAgentInfo(); $this->enableHttp2 = $this->canSafelyUseHttp2(); } public function __destruct() { $this->closeCurlHandle(); } public function initUserAgentInfo() { $curlVersion = \curl_version(); $this->userAgentInfo = [ 'httplib' => 'curl ' . $curlVersion['version'], 'ssllib' => $curlVersion['ssl_version'], ]; } public function getDefaultOptions() { return $this->defaultOptions; } public function getUserAgentInfo() { return $this->userAgentInfo; } /** * @return bool */ public function getEnablePersistentConnections() { return $this->enablePersistentConnections; } /** * @param bool $enable */ public function setEnablePersistentConnections($enable) { $this->enablePersistentConnections = $enable; } /** * @return bool */ public function getEnableHttp2() { return $this->enableHttp2; } /** * @param bool $enable */ public function setEnableHttp2($enable) { $this->enableHttp2 = $enable; } /** * @return null|callable */ public function getRequestStatusCallback() { return $this->requestStatusCallback; } /** * Sets a callback that is called after each request. The callback will * receive the following parameters: *

*
1. string $rbody The response body
*
2. integer $rcode The response status code
*
3. \Stripe\Util\CaseInsensitiveArray $rheaders The response headers
*
4. integer $errno The curl error number
*
5. string|null $message The curl error message
*
6. boolean $shouldRetry Whether the request will be retried
*
7. integer $numRetries The number of the retry attempt
*

. * * @param null|callable $requestStatusCallback */ public function setRequestStatusCallback($requestStatusCallback) { $this->requestStatusCallback = $requestStatusCallback; } // USER DEFINED TIMEOUTS const DEFAULT_TIMEOUT = 80; const DEFAULT_CONNECT_TIMEOUT = 30; private $timeout = self::DEFAULT_TIMEOUT; private $connectTimeout = self::DEFAULT_CONNECT_TIMEOUT; public function setTimeout($seconds) { $this->timeout = (int) \max($seconds, 0); return $this; } public function setConnectTimeout($seconds) { $this->connectTimeout = (int) \max($seconds, 0); return $this; } public function getTimeout() { return $this->timeout; } public function getConnectTimeout() { return $this->connectTimeout; } // END OF USER DEFINED TIMEOUTS private function constructRequest($method, $absUrl, $headers, $params, $hasFile) { $method = \strtolower($method); $opts = []; if (\is_callable($this->defaultOptions)) { // call defaultOptions callback, set options to return value $opts = \call_user_func_array($this->defaultOptions, \func_get_args()); if (!\is_array($opts)) { throw new Exception\UnexpectedValueException('Non-array value returned by defaultOptions CurlClient callback'); } } elseif (\is_array($this->defaultOptions)) { // set default curlopts from array $opts = $this->defaultOptions; } $params = Util\Util::objectsToIds($params); if ('get' === $method) { if ($hasFile) { throw new Exception\UnexpectedValueException( 'Issuing a GET request with a file parameter' ); } $opts[\CURLOPT_HTTPGET] = 1; if (\count($params) > 0) { $encoded = Util\Util::encodeParameters($params); $absUrl = "{$absUrl}?{$encoded}"; } } elseif ('post' === $method) { $opts[\CURLOPT_POST] = 1; $opts[\CURLOPT_POSTFIELDS] = $hasFile ? $params : Util\Util::encodeParameters($params); } elseif ('delete' === $method) { $opts[\CURLOPT_CUSTOMREQUEST] = 'DELETE'; if (\count($params) > 0) { $encoded = Util\Util::encodeParameters($params); $absUrl = "{$absUrl}?{$encoded}"; } } else { throw new Exception\UnexpectedValueException("Unrecognized method {$method}"); } // It is only safe to retry network failures on POST requests if we // add an Idempotency-Key header if (('post' === $method) && (Stripe::$maxNetworkRetries > 0)) { if (!$this->hasHeader($headers, 'Idempotency-Key')) { $headers[] = 'Idempotency-Key: ' . $this->randomGenerator->uuid(); } } // By default for large request body sizes (> 1024 bytes), cURL will // send a request without a body and with a `Expect: 100-continue` // header, which gives the server a chance to respond with an error // status code in cases where one can be determined right away (say // on an authentication problem for example), and saves the "large" // request body from being ever sent. // // Unfortunately, the bindings don't currently correctly handle the // success case (in which the server sends back a 100 CONTINUE), so // we'll error under that condition. To compensate for that problem // for the time being, override cURL's behavior by simply always // sending an empty `Expect:` header. $headers[] = 'Expect: '; $absUrl = Util\Util::utf8($absUrl); $opts[\CURLOPT_URL] = $absUrl; $opts[\CURLOPT_RETURNTRANSFER] = true; $opts[\CURLOPT_CONNECTTIMEOUT] = $this->connectTimeout; $opts[\CURLOPT_TIMEOUT] = $this->timeout; $opts[\CURLOPT_HTTPHEADER] = $headers; $opts[\CURLOPT_CAINFO] = Stripe::getCABundlePath(); if (!Stripe::getVerifySslCerts()) { $opts[\CURLOPT_SSL_VERIFYPEER] = false; } if (!isset($opts[\CURLOPT_HTTP_VERSION]) && $this->getEnableHttp2()) { // For HTTPS requests, enable HTTP/2, if supported $opts[\CURLOPT_HTTP_VERSION] = \CURL_HTTP_VERSION_2TLS; } // If the user didn't explicitly specify a CURLOPT_IPRESOLVE option, we // force IPv4 resolving as Stripe's API servers are only accessible over // IPv4 (see. https://github.com/stripe/stripe-php/issues/1045). // We let users specify a custom option in case they need to say proxy // through an IPv6 proxy. if (!isset($opts[\CURLOPT_IPRESOLVE])) { $opts[\CURLOPT_IPRESOLVE] = \CURL_IPRESOLVE_V4; } return [$opts, $absUrl]; } public function request($method, $absUrl, $headers, $params, $hasFile) { list($opts, $absUrl) = $this->constructRequest($method, $absUrl, $headers, $params, $hasFile); list($rbody, $rcode, $rheaders) = $this->executeRequestWithRetries($opts, $absUrl); return [$rbody, $rcode, $rheaders]; } public function requestStream($method, $absUrl, $headers, $params, $hasFile, $readBodyChunk) { list($opts, $absUrl) = $this->constructRequest($method, $absUrl, $headers, $params, $hasFile); $opts[\CURLOPT_RETURNTRANSFER] = false; list($rbody, $rcode, $rheaders) = $this->executeStreamingRequestWithRetries($opts, $absUrl, $readBodyChunk); return [$rbody, $rcode, $rheaders]; } /** * Curl permits sending \CURLOPT_HEADERFUNCTION, which is called with lines * from the header and \CURLOPT_WRITEFUNCTION, which is called with bytes * from the body. You usually want to handle the body differently depending * on what was in the header. * * This function makes it easier to specify different callbacks depending * on the contents of the heeder. After the header has been completely read * and the body begins to stream, it will call $determineWriteCallback with * the array of headers. $determineWriteCallback should, based on the * headers it receives, return a "writeCallback" that describes what to do * with the incoming HTTP response body. * * @param array $opts * @param callable $determineWriteCallback * * @return array */ private function useHeadersToDetermineWriteCallback($opts, $determineWriteCallback) { $rheaders = new Util\CaseInsensitiveArray(); $headerCallback = function ($curl, $header_line) use (&$rheaders) { return self::parseLineIntoHeaderArray($header_line, $rheaders); }; $writeCallback = null; $writeCallbackWrapper = function ($curl, $data) use (&$writeCallback, &$rheaders, &$determineWriteCallback) { if (null === $writeCallback) { $writeCallback = \call_user_func_array($determineWriteCallback, [$rheaders]); } return \call_user_func_array($writeCallback, [$curl, $data]); }; return [$headerCallback, $writeCallbackWrapper]; } private static function parseLineIntoHeaderArray($line, &$headers) { if (false === \strpos($line, ':')) { return \strlen($line); } list($key, $value) = \explode(':', \trim($line), 2); $headers[\trim($key)] = \trim($value); return \strlen($line); } /** * Like `executeRequestWithRetries` except: * 1. Does not buffer the body of a successful (status code < 300) * response into memory -- instead, calls the caller-provided * $readBodyChunk with each chunk of incoming data. * 2. Does not retry if a network error occurs while streaming the * body of a successful response. * * @param array $opts cURL options * @param string $absUrl * @param callable $readBodyChunk * * @return array */ public function executeStreamingRequestWithRetries($opts, $absUrl, $readBodyChunk) { /** @var bool */ $shouldRetry = false; /** @var int */ $numRetries = 0; // Will contain the bytes of the body of the last request // if it was not successful and should not be retries /** @var null|string */ $rbody = null; // Status code of the last request /** @var null|bool */ $rcode = null; // Array of headers from the last request /** @var null|array */ $lastRHeaders = null; $errno = null; $message = null; $determineWriteCallback = function ($rheaders) use ( &$readBodyChunk, &$shouldRetry, &$rbody, &$numRetries, &$rcode, &$lastRHeaders, &$errno ) { $lastRHeaders = $rheaders; $errno = \curl_errno($this->curlHandle); $rcode = \curl_getinfo($this->curlHandle, \CURLINFO_HTTP_CODE); // Send the bytes from the body of a successful request to the caller-provided $readBodyChunk. if ($rcode < 300) { $rbody = null; return function ($curl, $data) use (&$readBodyChunk) { // Don't expose the $curl handle to the user, and don't require them to // return the length of $data. \call_user_func_array($readBodyChunk, [$data]); return \strlen($data); }; } $shouldRetry = $this->shouldRetry($errno, $rcode, $rheaders, $numRetries); // Discard the body from an unsuccessful request that should be retried. if ($shouldRetry) { return function ($curl, $data) { return \strlen($data); }; } else { // Otherwise, buffer the body into $rbody. It will need to be parsed to determine // which exception to throw to the user. $rbody = ''; return function ($curl, $data) use (&$rbody) { $rbody .= $data; return \strlen($data); }; } }; while (true) { list($headerCallback, $writeCallback) = $this->useHeadersToDetermineWriteCallback($opts, $determineWriteCallback); $opts[\CURLOPT_HEADERFUNCTION] = $headerCallback; $opts[\CURLOPT_WRITEFUNCTION] = $writeCallback; $shouldRetry = false; $rbody = null; $this->resetCurlHandle(); \curl_setopt_array($this->curlHandle, $opts); $result = \curl_exec($this->curlHandle); $errno = \curl_errno($this->curlHandle); if (0 !== $errno) { $message = \curl_error($this->curlHandle); } if (!$this->getEnablePersistentConnections()) { $this->closeCurlHandle(); } if (\is_callable($this->getRequestStatusCallback())) { \call_user_func_array( $this->getRequestStatusCallback(), [$rbody, $rcode, $lastRHeaders, $errno, $message, $shouldRetry, $numRetries] ); } if ($shouldRetry) { ++$numRetries; $sleepSeconds = $this->sleepTime($numRetries, $lastRHeaders); \usleep((int) ($sleepSeconds * 1000000)); } else { break; } } if (0 !== $errno) { $this->handleCurlError($absUrl, $errno, $message, $numRetries); } return [$rbody, $rcode, $lastRHeaders]; } /** * @param array $opts cURL options * @param string $absUrl */ public function executeRequestWithRetries($opts, $absUrl) { $numRetries = 0; while (true) { $rcode = 0; $errno = 0; $message = null; // Create a callback to capture HTTP headers for the response $rheaders = new Util\CaseInsensitiveArray(); $headerCallback = function ($curl, $header_line) use (&$rheaders) { return CurlClient::parseLineIntoHeaderArray($header_line, $rheaders); }; $opts[\CURLOPT_HEADERFUNCTION] = $headerCallback; $this->resetCurlHandle(); \curl_setopt_array($this->curlHandle, $opts); $rbody = \curl_exec($this->curlHandle); if (false === $rbody) { $errno = \curl_errno($this->curlHandle); $message = \curl_error($this->curlHandle); } else { $rcode = \curl_getinfo($this->curlHandle, \CURLINFO_HTTP_CODE); } if (!$this->getEnablePersistentConnections()) { $this->closeCurlHandle(); } $shouldRetry = $this->shouldRetry($errno, $rcode, $rheaders, $numRetries); if (\is_callable($this->getRequestStatusCallback())) { \call_user_func_array( $this->getRequestStatusCallback(), [$rbody, $rcode, $rheaders, $errno, $message, $shouldRetry, $numRetries] ); } if ($shouldRetry) { ++$numRetries; $sleepSeconds = $this->sleepTime($numRetries, $rheaders); \usleep((int) ($sleepSeconds * 1000000)); } else { break; } } if (false === $rbody) { $this->handleCurlError($absUrl, $errno, $message, $numRetries); } return [$rbody, $rcode, $rheaders]; } /** * @param string $url * @param int $errno * @param string $message * @param int $numRetries * * @throws Exception\ApiConnectionException */ private function handleCurlError($url, $errno, $message, $numRetries) { switch ($errno) { case \CURLE_COULDNT_CONNECT: case \CURLE_COULDNT_RESOLVE_HOST: case \CURLE_OPERATION_TIMEOUTED: $msg = "Could not connect to Stripe ({$url}). Please check your " . 'internet connection and try again. If this problem persists, ' . "you should check Stripe's service status at " . 'https://twitter.com/stripestatus, or'; break; case \CURLE_SSL_CACERT: case \CURLE_SSL_PEER_CERTIFICATE: $msg = "Could not verify Stripe's SSL certificate. Please make sure " . 'that your network is not intercepting certificates. ' . "(Try going to {$url} in your browser.) " . 'If this problem persists,'; break; default: $msg = 'Unexpected error communicating with Stripe. ' . 'If this problem persists,'; } $msg .= ' let us know at support@stripe.com.'; $msg .= "\n\n(Network error [errno {$errno}]: {$message})"; if ($numRetries > 0) { $msg .= "\n\nRequest was retried {$numRetries} times."; } throw new Exception\ApiConnectionException($msg); } /** * Checks if an error is a problem that we should retry on. This includes both * socket errors that may represent an intermittent problem and some special * HTTP statuses. * * @param int $errno * @param int $rcode * @param array|\Stripe\Util\CaseInsensitiveArray $rheaders * @param int $numRetries * * @return bool */ private function shouldRetry($errno, $rcode, $rheaders, $numRetries) { if ($numRetries >= Stripe::getMaxNetworkRetries()) { return false; } // Retry on timeout-related problems (either on open or read). if (\CURLE_OPERATION_TIMEOUTED === $errno) { return true; } // Destination refused the connection, the connection was reset, or a // variety of other connection failures. This could occur from a single // saturated server, so retry in case it's intermittent. if (\CURLE_COULDNT_CONNECT === $errno) { return true; } // The API may ask us not to retry (eg; if doing so would be a no-op) // or advise us to retry (eg; in cases of lock timeouts); we defer to that. if (isset($rheaders['stripe-should-retry'])) { if ('false' === $rheaders['stripe-should-retry']) { return false; } if ('true' === $rheaders['stripe-should-retry']) { return true; } } // 409 Conflict if (409 === $rcode) { return true; } // Retry on 500, 503, and other internal errors. // // Note that we expect the stripe-should-retry header to be false // in most cases when a 500 is returned, since our idempotency framework // would typically replay it anyway. if ($rcode >= 500) { return true; } return false; } /** * Provides the number of seconds to wait before retrying a request. * * @param int $numRetries * @param array|\Stripe\Util\CaseInsensitiveArray $rheaders * * @return int */ private function sleepTime($numRetries, $rheaders) { // Apply exponential backoff with $initialNetworkRetryDelay on the // number of $numRetries so far as inputs. Do not allow the number to exceed // $maxNetworkRetryDelay. $sleepSeconds = \min( Stripe::getInitialNetworkRetryDelay() * 1.0 * 2 ** ($numRetries - 1), Stripe::getMaxNetworkRetryDelay() ); // Apply some jitter by randomizing the value in the range of // ($sleepSeconds / 2) to ($sleepSeconds). $sleepSeconds *= 0.5 * (1 + $this->randomGenerator->randFloat()); // But never sleep less than the base sleep seconds. $sleepSeconds = \max(Stripe::getInitialNetworkRetryDelay(), $sleepSeconds); // And never sleep less than the time the API asks us to wait, assuming it's a reasonable ask. $retryAfter = isset($rheaders['retry-after']) ? (float) ($rheaders['retry-after']) : 0.0; if (\floor($retryAfter) === $retryAfter && $retryAfter <= Stripe::getMaxRetryAfter()) { $sleepSeconds = \max($sleepSeconds, $retryAfter); } return $sleepSeconds; } /** * Initializes the curl handle. If already initialized, the handle is closed first. */ private function initCurlHandle() { $this->closeCurlHandle(); $this->curlHandle = \curl_init(); } /** * Closes the curl handle if initialized. Do nothing if already closed. */ private function closeCurlHandle() { if (null !== $this->curlHandle) { \curl_close($this->curlHandle); $this->curlHandle = null; } } /** * Resets the curl handle. If the handle is not already initialized, or if persistent * connections are disabled, the handle is reinitialized instead. */ private function resetCurlHandle() { if (null !== $this->curlHandle && $this->getEnablePersistentConnections()) { \curl_reset($this->curlHandle); } else { $this->initCurlHandle(); } } /** * Indicates whether it is safe to use HTTP/2 or not. * * @return bool */ private function canSafelyUseHttp2() { // Versions of curl older than 7.60.0 don't respect GOAWAY frames // (cf. https://github.com/curl/curl/issues/2416), which Stripe use. $curlVersion = \curl_version()['version']; return \version_compare($curlVersion, '7.60.0') >= 0; } /** * Checks if a list of headers contains a specific header name. * * @param string[] $headers * @param string $name * * @return bool */ private function hasHeader($headers, $name) { foreach ($headers as $header) { if (0 === \strncasecmp($header, "{$name}: ", \strlen($name) + 2)) { return true; } } return false; } }