Re: Port random_bytes to PHP 5

On 10/12/15 10:53 PM, Larry Garfield wrote:

On 10/12/2015 07:29 PM, Tom Worster wrote:

Could we regard random_bytes() as a security patch rather than a new feature and therefore port it to PHP 5? Error handling would have to change but that should be feasible. Iirc, earlier commits of random_bytes() had PHP 5-like behavior on error. My motivation: it's easier to defend abandoning OpenSSL's RNG (e.g. in paragonie/random_compat) if we could say to Windows users stuck with nothing else: "Upgrade to the latest point release of PHP 5.x. It has a proper fix." Tom

Since there's no 5.7 release planned, you're talking about adding it in a 5.6.x?

Yes, maybe even 5.5?

What's wrong with the random_compat library as a solution for 5.6 users?

Good question. Vexing answer. I try to be brief. There are real situations that push random_compat into a corner with only unpleasant options, namely recommending the user install the unsavory mcrypt ext, which provides mcrypt_create_iv(), or resort to OpenSSL's RNG, which is just scary. There are recent discussion of this in a few places, I think you can find them all starting here https://github.com/paragonie/random_compat/issues/5 So I thought another option would be to say "patch your PHP". One possibility to do that is what I proposed above. [I hesitate to mention it but, another is to make mcrypt_create_iv() independent of libmcrypt and present in standard builds of PHP. Maybe the latter is better because existing scripts that test function_exists('mcrypt_create_iv') become more secure.] Tom