Date: Fri, 30 Mar 2012 23:05:32 +0400 From: Solar Designer <solar@...nwall.com> To: Jeff Law <law@...hat.com> Cc: oss-security@...ts.openwall.com Subject: Re: glibc crypt(3), crypt_r(3), PHP crypt() may use alloca() On Fri, Mar 30, 2012 at 12:47:54PM -0600, Jeff Law wrote: > On 03/30/2012 12:43 PM, Solar Designer wrote: > >On Fri, Mar 30, 2012 at 12:27:31PM -0600, Jeff Law wrote: > >>I think the right way to handle the return value is to return NULL for > >>these cases. It's posix complaint and the glibc crypt routines already > >>return NULL for exceptional conditions. > > > >Do you realize that plenty of services that use crypt() - likely the > >majority of them, even - don't handle NULL returns, so they will > >segfault when these conditions are triggered? > Then, IMHO, the app is clearly broken. Crypt has been defined as > potentially returning NULL and at least for glibc has done so since the > introduction of sha256/sha512, if the app fails to check for that, then > the app needs to be fixed. Sure. I am not arguing against fixing the apps (in fact, I am planning to fix one of mine - code originally written in 1998 or so - regardless of what glibc does on this), but I am arguing for not having glibc expose the problem. Considering the age of Unix, SUSv2 and POSIX.1-2001 are fairly recent (I think this may be when the NULL returns were first standardized), and glibc's SHA-crypt is very young. It still makes sense to support apps older than that, including without changes. > I don't speak for glibc on this issue, so if you want to raise it on > libc-alpha, go for it. I was hoping that you would take care of that. ;-) Anyway, given DragonFly's decision, various other systems returning NULL on various occasions (inconsistently), and your comment about glibc doing that for a while, I no longer have a strong opinion on the matter. We will likely continue to do the "*0" / "*1" thing in Owl (our distro that uses glibc with patches), though. Alexander
Powered by blists - more mailing lists
Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.