Re: [RFC] RNG fixes

On Tue, Jun 14, 2016 at 12:46 PM, Leigh <leight@gmail.com> wrote: > Hey Internals, > > I realise I'm cutting it close with this one, but I want to propose some > changes to our standard random number generators. > > The downside of this proposal is that our RNGs (rand() and mt_rand()) are > seedable and reproduce identical streams (platform dependant) for any given > seed. However their implementations are broken or inconsistent, so we need > to weigh up the cost of changing these sequences versus having solid > implementations. > > It is my opinion that if we are going to make any changes to these > functions, we should make all of the changes at the same time and avoid any > future disruption to their output. > > The RFC contains a few proposals, some of them depend on each other while > others are standalone. Throughout the discussion phase I hope to reduce the > number of proposals down to a consensus we can vote on in two weeks time. > > I will release a patch when I have a better feeling for the direction we > want to take. > > The issues I want to bring up for discussion are. > > * Replacing mt_rand() and rand() to a strong, modern RNG. > * Alternatively, fixing the current mt_rand() implementation to make it > standard > * Aliasing rand() to mt_rand() to improve output and cross-platform support > * Fixing RAND_RANGE for large ranges. > * Replacing insecure uses of php_rand() with php_random_bytes() > * Making the array_rand() algorithm more efficient > > The RFC can be found here: https://wiki.php.net/rfc/rng_fixes > > If anyone knows of other fixes that should be made at the same time but I > have overlooked, please let me know so I can get them included. > > Regards, > > Leigh. > Good idea.​ I'm particularly fond of PCG over MT and LCG (but would not ever use it for a CSPRNG). Scott Arciszewski Chief Development Officer Paragon Initiative Enterprises <https://paragonie.com/>​