On Fri, May 02, 2014 at 02:56:59PM +1000, Damien Miller wrote: > On Thu, 1 May 2014, Brent Cook wrote: > > > Hi, > > > > I have been working on a portable LibreSSL build tree for a little > > while to test the waters: http://github.com/busterb/libressl > > > > Someone noticed an issue with the arc4random > > implementation that I originally grabbed from libbsd > > https://github.com/busterb/libressl/issues/1 > > > > So, I looked at how OpenSSH handles it, and noticed that it uses the > > random functions from OpenSSL unconditionally to seed the state of its > > version of arc4random. > > I haven't ported the no-OpenSSL changes yet and haven't thought about > how I'll handle arc4random. > > I'll probably make an explicit arc4random_stir() function that we can > call in various places. OpenBSD has put some effort in to ensure that > the kernel PRNG is available in pretty much any context (privileged, > unprivileged, in chroot without devices, etc.) and AFAIK no other OS > does this. NetBSD and FreeBSD (as of 10.0) both use a sysctl, just like OpenBSD. Linux also has an obscure sysctl which pulls directly from the internal CSPRNG. So all of these will work in a jail without /dev or /proc. OS X still seeds itself from /dev/urandom in its arc4random implementation, as it inherited FreeBSD's old code. Solaris sadly only has /dev/urandom. For my Lua bindings to OpenSSL I use all of these different mechanisms to explicitly seed OpenSSL. The code is in randL_stir. Here's a direct link: https://github.com/wahern/luaossl/blob/dd0ad8dc1b0962fc80dbf680aadaaaba6536c96b/src/openssl.c#L4008 _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
