Re: [RFC] [DISCUSSION] Reliable user-land CSPRNG

Hi Andrey, On 24 February 2015 at 09:51, Andrey Andreev <narf@devilix.net> wrote: > I noticed that the patch checks for /dev/arandom availability first, > and I'm pretty sure that on systems that have it, /dev/urandom simply > redirects to /dev/urandom, so that might be a bit redundant ... Maybe > Leigh can say more about this if I'm missing something. You're absolutely right, on modern releases of systems like OpenBSD and OSX /dev/urandom is simply an alias of /dev/arandom. The problem is, I'm not an expert in _every_ version of _every_ OS, and it might not always be the case that this aliasing exists. I'd also like to think this adds an element of future-proofing. If I wish for it hard enough, maybe one day Linux in general will introduce /dev/arandom, but maybe at first /dev/urandom does not alias it until some time later. > Also, you don't need 100s of lines of code to write the same thing in > userland ... you need ~30 lines, your Facebook SDK example is just > over-complicated. I'm sure everybody will agree that this is a feature > that PHP needs, so I think you should rather focus on explaining that > it's better than leaving it to userland implementations that may screw > up a lot of details. I agree, we can make a succinct explanation that focuses on the importance of "getting it right". > And finally, a suggestion to remove the default $length value of 16 > for random_bytes() - it just happens to be what you need for i.e. an > AES-128 IV, but other than that it doesn't make sense to have a > default length. This is just a badly formatted part of the RFC. There is no default for random_bytes(). The defaults for random_int() are however +/- PHP_INT_MAX > Otherwise - great! I'm really looking forward to this, and many others > surely do as well. I've got no doubt that the RFC will pass and I > intend to write a compat package for use in pre-PHP7 environments, to > ease the new API's adoption. Thanks :)