Bug #74961 [Opn]: "Disallow non-crypto hashes in HMAC and PBKDF2" implemented poorly

Edit report at https://bugs.php.net/bug.php?id=74961&edit=1 ID: 74961 Updated by: pollita@php.net Reported by: bluebaroncanada at gmail dot com Summary: "Disallow non-crypto hashes in HMAC and PBKDF2" implemented poorly Status: Open Type: Bug Package: *Encryption and hash functions PHP Version: 7.2.0beta1 Block user comment: N Private report: N New Comment: I'm confused why you care how the flag (flag mind you, not function) is implemented. Why does it matter that the algo has a bit set on its definition rather than having a completely separate lookup table? The way it looks from userspace is the same. Previous Comments: ------------------------------------------------------------------------ [2017-07-27 19:07:20] bluebaroncanada at gmail dot com The rest of the request is to undo some of these changes that are cumbersome, difficult to maintain, and hard to research to build new code on top. It's certainly unnecessary and highly-coupled to put is_crypto functions that are only used once inside the hash functions. That's just an extra layer of coupling for no reason. It's going to make it more likely to have a bug. Instead, let's have a canonical function that tells all that both the user and the developer can rely on. ------------------------------------------------------------------------ [2017-07-23 18:39:24] pollita@php.net I'm a little unclear on what you're looking for when you say "rewritten". I see the request for hash_algos_hmac() which is entirely reasonable (or a variant thereof), but I'm not sure what the rest of the request is... ------------------------------------------------------------------------ [2017-07-21 09:10:08] bluebaroncanada at gmail dot com Description: ------------ Commit https://github.com/php/php-src/commit/d89d149edf39cf4ce9ab41979f246e82510d43a5#commitcomment-23109176 is a poor implementation of its goal. It salted the code and added a new is_crypto function which wasn't necessary and is also insufficient. It should provide a new hash_algos_hmac to extend http://php.net/manual/en/function.hash-algos.php The documentation now says "Returns FALSE when algo is unknown." and 7.2.0 Usage of non-cryptographic hash functions (adler32, crc32, crc32b, fnv132, fnv1a32, fnv164, fnv1a64, joaat) was disabled. However it does not say that it will return false only when providing one of these non-cryptographic functions, which is what it actually does. There could be future deprecation of more functions. I suggest that either the is_crypto function is extended to the users, but better than that, we should remove the is_crypto function and create the hash_algos_hmac to extend the hash_algos function for the same reason its predecessor exits and also so that we can use that function internally to decide if the hashing algorithm should be available and thus easily allow future deprecation and pedantic decisions on available algorithms without further damaging the code. The reason that this bothers me so is that phpseclib extends this functionality and it cannot properly test with this implementation or properly extend this functionality to pass on to its users. In the future, if there is further deprecation, users would be treated with an undetectable error. This commit should be removed and rewritten. Test script: --------------- if (!hash_hmac('crc32', 'The quick brown fox jumped over the lazy dog.', 'secret')) die('run for your lives'); ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=74961&edit=1