> Hi list, > > A couple of bug reports have highlighted the fact that our > openssl_encrypt and openssl_decrupt functions have no way of getting > or setting tags required for authenticated cipher modes (i.e. GCM, > CCM, OCB (not sure if this is available in OpenSSL)). > > https://bugs.php.net/bug.php?id=68962 > https://bugs.php.net/bug.php?id=67304 > > Further to this, we have no way of setting any associated data. > > I think we absolutely must provide a method for users to be able to > use authenticated encryption, and would like some opinions on how much > flexibility we give users, and the best method for exposing this > functionality. > > At the very basic end of the spectrum, we could have openssl_get_tag > and openssl_set_tag, or add an extra parameter to the end of > openssl_encrypt and openssl_decrypt (pass by ref for encrypt, like > preg $matches) this would cover the majority of use cases. > > However I absolutely think that the associated data also needs to be > supported, and possibly the ability to change the tag length. > > At this point we're starting to get into the territory where an > $options array is needed, or we add a lot of parameters to the end of > functions. I don't really think it's good to add up to 3 more params > to these functions. > > What do you guys and girls think is the best way of tackling this?
How about ... Old API: -------- string openssl_decrypt ( string $data , string $method , string $password [, int $options = 0 [, string $iv = "" ]] ) string openssl_encrypt ( string $data , string $method , string $password [, int $options = 0 [, string $iv = "" ]] ) New: -------- mixed openssl_decrypt ( string $data , string $method , string $password [, mixed $options = 0 [, string $iv = "" ]] ) string openssl_encrypt ( string $data , string $method , string $password [, mixed $options = 0 [, string $iv = "" ]] ) The main changes are: - the $options parameter becomes mixed (either long or array) in both functions - a long $options parameter triggers E_DEPRECATED in php7 (expects array) - the presence of an $iv triggers E_DEPRECATED in php7 (scheduled for removal) - openssl_decrypt() now returns mixed ... if $options['get_tag'] == true then return [$decryptedString, $tag], otherwise return $decrypted string as before to preserve BC. - the encrypt function could use $options['set_tag'] to define that (or any other secondary information needed for the operation). This has zero BC implications, emits deprecation warnings for the old way of doing it and finally provides a schedule for eventual removal of the excessively verbose API in PHP8. What I would prefer NOT to see is piling on more optional parameters to these already too-long function signatures. Also, I don't really like the idea of adding "state" to this operation with new openssl_set_tag/openssl_get_tag functions. Thoughts?
