public function validateTransactions($object, array $xactions)
{
$viewer = $this->getActor();
$errors = array();
$ics_type = PhabricatorCalendarICSURIImportEngine::ENGINETYPE;
$import_type = $object->getEngine()->getImportEngineType();
if ($import_type != $ics_type) {
if (!$xactions) {
return $errors;
}
$errors[] = $this->newInvalidError(pht('You can not attach an ICS URI to an import type other than ' . 'an ICS URI import (type is "%s").', $import_type));
return $errors;
}
$new_value = $object->getParameter(self::PARAMKEY_URI);
foreach ($xactions as $xaction) {
$new_value = $xaction->getNewValue();
if (!strlen($new_value)) {
continue;
}
try {
PhabricatorEnv::requireValidRemoteURIForFetch($new_value, array('http', 'https'));
} catch (Exception $ex) {
$errors[] = $this->newInvalidError($ex->getMessage(), $xaction);
}
}
if (!strlen($new_value)) {
$errors[] = $this->newRequiredError(pht('You must select an ".ics" URI to import.'));
}
return $errors;
}
/**
* Download a remote resource over HTTP and save the response body as a file.
*
* This method respects `security.outbound-blacklist`, and protects against
* HTTP redirection (by manually following "Location" headers and verifying
* each destination). It does not protect against DNS rebinding. See
* discussion in T6755.
*/
public static function newFromFileDownload($uri, array $params = array())
{
$timeout = 5;
$redirects = array();
$current = $uri;
while (true) {
try {
if (count($redirects) > 10) {
throw new Exception(pht('Too many redirects trying to fetch remote URI.'));
}
$resolved = PhabricatorEnv::requireValidRemoteURIForFetch($current, array('http', 'https'));
list($resolved_uri, $resolved_domain) = $resolved;
$current = new PhutilURI($current);
if ($current->getProtocol() == 'http') {
// For HTTP, we can use a pre-resolved URI to defuse DNS rebinding.
$fetch_uri = $resolved_uri;
$fetch_host = $resolved_domain;
} else {
// For HTTPS, we can't: cURL won't verify the SSL certificate if
// the domain has been replaced with an IP. But internal services
// presumably will not have valid certificates for rebindable
// domain names on attacker-controlled domains, so the DNS rebinding
// attack should generally not be possible anyway.
$fetch_uri = $current;
$fetch_host = null;
}
$future = id(new HTTPSFuture($fetch_uri))->setFollowLocation(false)->setTimeout($timeout);
if ($fetch_host !== null) {
$future->addHeader('Host', $fetch_host);
}
list($status, $body, $headers) = $future->resolve();
if ($status->isRedirect()) {
// This is an HTTP 3XX status, so look for a "Location" header.
$location = null;
foreach ($headers as $header) {
list($name, $value) = $header;
if (phutil_utf8_strtolower($name) == 'location') {
$location = $value;
break;
}
}
// HTTP 3XX status with no "Location" header, just treat this like
// a normal HTTP error.
if ($location === null) {
throw $status;
}
if (isset($redirects[$location])) {
throw new Exception(pht('Encountered loop while following redirects.'));
}
$redirects[$location] = $location;
$current = $location;
// We'll fall off the bottom and go try this URI now.
} else {
if ($status->isError()) {
// This is something other than an HTTP 2XX or HTTP 3XX status, so
// just bail out.
throw $status;
} else {
// This is HTTP 2XX, so use the response body to save the
// file data.
$params = $params + array('name' => basename($uri));
return self::newFromFileData($body, $params);
}
}
} catch (Exception $ex) {
if ($redirects) {
throw new PhutilProxyException(pht('Failed to fetch remote URI "%s" after following %s redirect(s) ' . '(%s): %s', $uri, new PhutilNumber(count($redirects)), implode(' > ', array_keys($redirects)), $ex->getMessage()), $ex);
} else {
throw $ex;
}
}
}
}