/**
* Hash a one-time login key for storage as a temporary token.
*
* @param PhabricatorUser User this key is for.
* @param PhabricatorUserEmail Optionally, email to verify when
* link is used.
* @param string The one time login key.
* @return string Hash of the key.
* task onetime
*/
private function getOneTimeLoginKeyHash(PhabricatorUser $user, PhabricatorUserEmail $email = null, $key = null)
{
$parts = array($key, $user->getAccountSecret());
if ($email) {
$parts[] = $email->getVerificationCode();
}
return PhabricatorHash::digest(implode(':', $parts));
}
/**
* Compute a chunked file hash for the viewer.
*
* We can not currently compute a real hash for chunked file uploads (because
* no process sees all of the file data).
*
* We also can not trust the hash that the user claims to have computed. If
* we trust the user, they can upload some `evil.exe` and claim it has the
* same file hash as `good.exe`. When another user later uploads the real
* `good.exe`, we'll just create a reference to the existing `evil.exe`. Users
* who download `good.exe` will then receive `evil.exe`.
*
* Instead, we rehash the user's claimed hash with account secrets. This
* allows users to resume file uploads, but not collide with other users.
*
* Ideally, we'd like to be able to verify hashes, but this is complicated
* and time consuming and gives us a fairly small benefit.
*
* @param PhabricatorUser Viewing user.
* @param string Claimed file hash.
* @return string Rehashed file hash.
*/
public static function getChunkedHash(PhabricatorUser $viewer, $hash)
{
if (!$viewer->getPHID()) {
throw new Exception(pht('Unable to compute chunked hash without real viewer!'));
}
$input = $viewer->getAccountSecret() . ':' . $hash . ':' . $viewer->getPHID();
return self::getChunkedHashForInput($input);
}
