function testParseHTTPDateFail()
{
$times = array('NOW', 'Wednesday, 13-Oct-10 10:26:00 UTC', 'Wed Oct 6 10:26:00 2010');
foreach ($times as $time) {
$this->assertFalse(Sabre_HTTP_Util::parseHTTPDate($time), 'We used the string: ' . $time);
}
}
function testStrtotimeFail()
{
// Strtotime may return -1 when the date cannot be parsed.
// We are simulating this situation by testing a date that actually
// results in -1. (because I have found no other way to break this
// code)
$time = 'Wed, 13 Oct 1960 10:26:00 GMT';
$this->assertNull(Sabre_HTTP_Util::parseHTTPDate($time));
}
/**
* Makes sure the supplied value is a valid RFC2616 date.
*
* If we would just use strtotime to get a valid timestamp, we have no way of checking if a
* user just supplied the word 'now' for the date header.
*
* This function also makes sure the Date header is within 15 minutes of the operating
* system date, to prevent replay attacks.
*
* @param string $dateHeader
* @return bool
*/
protected function validateRFC2616Date($dateHeader)
{
$date = Sabre_HTTP_Util::parseHTTPDate($dateHeader);
// Unknown format
if (!$date) {
$this->errorCode = self::ERR_INVALIDDATEFORMAT;
return false;
}
$min = new DateTime('-15 minutes');
$max = new DateTime('+15 minutes');
// We allow 15 minutes around the current date/time
if ($date > $max || $date < $min) {
$this->errorCode = self::ERR_REQUESTTIMESKEWED;
return false;
}
return $date;
}
/**
* This method checks the main HTTP preconditions.
*
* Currently these are:
* * If-Match
* * If-None-Match
* * If-Modified-Since
* * If-Unmodified-Since
*
* The method will return true if all preconditions are met
* The method will return false, or throw an exception if preconditions
* failed. If false is returned the operation should be aborted, and
* the appropriate HTTP response headers are already set.
*
* Normally this method will throw 412 Precondition Failed for failures
* related to If-None-Match, If-Match and If-Unmodified Since. It will
* set the status to 304 Not Modified for If-Modified_since.
*
* If the $handleAsGET argument is set to true, it will also return 304
* Not Modified for failure of the If-None-Match precondition. This is the
* desired behaviour for HTTP GET and HTTP HEAD requests.
*
* @param bool $handleAsGET
* @return bool
*/
public function checkPreconditions($handleAsGET = false)
{
$uri = $this->getRequestUri();
$node = null;
$lastMod = null;
$etag = null;
if ($ifMatch = $this->httpRequest->getHeader('If-Match')) {
// If-Match contains an entity tag. Only if the entity-tag
// matches we are allowed to make the request succeed.
// If the entity-tag is '*' we are only allowed to make the
// request succeed if a resource exists at that url.
try {
$node = $this->tree->getNodeForPath($uri);
} catch (Sabre_DAV_Exception_NotFound $e) {
throw new Sabre_DAV_Exception_PreconditionFailed('An If-Match header was specified and the resource did not exist', 'If-Match');
}
// Only need to check entity tags if they are not *
if ($ifMatch !== '*') {
// There can be multiple etags
$ifMatch = explode(',', $ifMatch);
$haveMatch = false;
foreach ($ifMatch as $ifMatchItem) {
// Stripping any extra spaces
$ifMatchItem = trim($ifMatchItem, ' ');
$etag = $node->getETag();
if ($etag === $ifMatchItem) {
$haveMatch = true;
}
}
if (!$haveMatch) {
throw new Sabre_DAV_Exception_PreconditionFailed('An If-Match header was specified, but none of the specified the ETags matched.', 'If-Match');
}
}
}
if ($ifNoneMatch = $this->httpRequest->getHeader('If-None-Match')) {
// The If-None-Match header contains an etag.
// Only if the ETag does not match the current ETag, the request will succeed
// The header can also contain *, in which case the request
// will only succeed if the entity does not exist at all.
$nodeExists = true;
if (!$node) {
try {
$node = $this->tree->getNodeForPath($uri);
} catch (Sabre_DAV_Exception_NotFound $e) {
$nodeExists = false;
}
}
if ($nodeExists) {
$haveMatch = false;
if ($ifNoneMatch === '*') {
$haveMatch = true;
} else {
// There might be multiple etags
$ifNoneMatch = explode(',', $ifNoneMatch);
$etag = $node->getETag();
foreach ($ifNoneMatch as $ifNoneMatchItem) {
// Stripping any extra spaces
$ifNoneMatchItem = trim($ifNoneMatchItem, ' ');
if ($etag === $ifNoneMatchItem) {
$haveMatch = true;
}
}
}
if ($haveMatch) {
if ($handleAsGET) {
$this->httpResponse->sendStatus(304);
return false;
} else {
throw new Sabre_DAV_Exception_PreconditionFailed('An If-None-Match header was specified, but the ETag matched (or * was specified).', 'If-None-Match');
}
}
}
}
if (!$ifNoneMatch && ($ifModifiedSince = $this->httpRequest->getHeader('If-Modified-Since'))) {
// The If-Modified-Since header contains a date. We
// will only return the entity if it has been changed since
// that date. If it hasn't been changed, we return a 304
// header
// Note that this header only has to be checked if there was no If-None-Match header
// as per the HTTP spec.
$date = Sabre_HTTP_Util::parseHTTPDate($ifModifiedSince);
if ($date) {
if (is_null($node)) {
$node = $this->tree->getNodeForPath($uri);
}
$lastMod = $node->getLastModified();
if ($lastMod) {
$lastMod = new DateTime('@' . $lastMod);
if ($lastMod <= $date) {
$this->httpResponse->sendStatus(304);
$this->httpResponse->setHeader('Last-Modified', Sabre_HTTP_Util::toHTTPDate($lastMod));
return false;
}
}
}
}
if ($ifUnmodifiedSince = $this->httpRequest->getHeader('If-Unmodified-Since')) {
// The If-Unmodified-Since will allow allow the request if the
// entity has not changed since the specified date.
$date = Sabre_HTTP_Util::parseHTTPDate($ifUnmodifiedSince);
// We must only check the date if it's valid
if ($date) {
if (is_null($node)) {
$node = $this->tree->getNodeForPath($uri);
}
$lastMod = $node->getLastModified();
if ($lastMod) {
$lastMod = new DateTime('@' . $lastMod);
if ($lastMod > $date) {
throw new Sabre_DAV_Exception_PreconditionFailed('An If-Unmodified-Since header was specified, but the entity has been changed since the specified date.', 'If-Unmodified-Since');
}
}
}
}
return true;
}