Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On Fri, Dec 23, 2016 at 7:19 PM, Hannes Frederic Sowa wrote: > Factoring out sha3 Per the other thread, you probably don't actually want SHA3, because it's slow in software. You want SHA2. If you want something faster and better, then Blake2 is most certainly the way

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On 23.12.2016 17:42, Andy Lutomirski wrote: > On Fri, Dec 23, 2016 at 8:23 AM, Andy Lutomirski wrote: >> On Fri, Dec 23, 2016 at 3:59 AM, Daniel Borkmann >> wrote: >>> On 12/23/2016 11:59 AM, Hannes Frederic Sowa wrote: On Fri, 2016-12-23 at

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On Fri, Dec 23, 2016 at 8:23 AM, Andy Lutomirski wrote: > On Fri, Dec 23, 2016 at 3:59 AM, Daniel Borkmann wrote: >> On 12/23/2016 11:59 AM, Hannes Frederic Sowa wrote: >>> >>> On Fri, 2016-12-23 at 11:04 +0100, Daniel Borkmann wrote: On

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On Fri, Dec 23, 2016 at 3:59 AM, Daniel Borkmann wrote: > On 12/23/2016 11:59 AM, Hannes Frederic Sowa wrote: >> >> On Fri, 2016-12-23 at 11:04 +0100, Daniel Borkmann wrote: >>> >>> On 12/22/2016 05:59 PM, Hannes Frederic Sowa wrote: On Thu, 2016-12-22 at 08:07

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On 12/23/2016 11:59 AM, Hannes Frederic Sowa wrote: On Fri, 2016-12-23 at 11:04 +0100, Daniel Borkmann wrote: On 12/22/2016 05:59 PM, Hannes Frederic Sowa wrote: On Thu, 2016-12-22 at 08:07 -0800, Andy Lutomirski wrote: [...] The hashing is not a proper sha1 neither, unfortunately. I think

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On Fri, 2016-12-23 at 11:04 +0100, Daniel Borkmann wrote: > On 12/22/2016 05:59 PM, Hannes Frederic Sowa wrote: > > On Thu, 2016-12-22 at 08:07 -0800, Andy Lutomirski wrote: > > > On Thu, Dec 22, 2016 at 7:51 AM, Hannes Frederic Sowa > > > wrote: > > > > On Thu,

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On 12/22/2016 06:25 PM, Andy Lutomirski wrote: On Thu, Dec 22, 2016 at 8:59 AM, Hannes Frederic Sowa [...] I wondered if bpf program loading should have used the module loading infrastructure from the beginning... That would be way too complicated and would be nasty for the unprivileged

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On 12/22/2016 05:59 PM, Hannes Frederic Sowa wrote: On Thu, 2016-12-22 at 08:07 -0800, Andy Lutomirski wrote: On Thu, Dec 22, 2016 at 7:51 AM, Hannes Frederic Sowa wrote: On Thu, 2016-12-22 at 16:41 +0100, Jason A. Donenfeld wrote: On Thu, Dec 22, 2016 at 4:33 PM,

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On 22.12.2016 20:56, Andy Lutomirski wrote: > It's also not quite clear to me why userspace needs to be able to > calculate the digest on its own. A bpf(BPF_CALC_PROGRAM_DIGEST) > command that takes a BPF program as input and hashes it would seem to > serve the same purpose, and that would allow

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On Thu, Dec 22, 2016 at 11:34 AM, Alexei Starovoitov wrote: > On Thu, Dec 22, 2016 at 9:25 AM, Andy Lutomirski wrote: >> On Thu, Dec 22, 2016 at 8:59 AM, Hannes Frederic Sowa >> wrote: >>> On Thu, 2016-12-22 at 08:07

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On Thu, Dec 22, 2016 at 9:25 AM, Andy Lutomirski wrote: > On Thu, Dec 22, 2016 at 8:59 AM, Hannes Frederic Sowa > wrote: >> On Thu, 2016-12-22 at 08:07 -0800, Andy Lutomirski wrote: >> >> We don't prevent ebpf programs being loaded based on the

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On Thu, Dec 22, 2016 at 5:59 PM, Hannes Frederic Sowa wrote: > We don't prevent ebpf programs being loaded based on the digest but > just to uniquely identify loaded programs from user space and match up > with their source. Okay, so in that case, a weak hashing

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On Thu, 2016-12-22 at 09:25 -0800, Andy Lutomirski wrote: > On Thu, Dec 22, 2016 at 8:59 AM, Hannes Frederic Sowa > wrote: > > On Thu, 2016-12-22 at 08:07 -0800, Andy Lutomirski wrote: > > > > > > You mean: > > > > > > commit 7bd509e311f408f7a5132fcdde2069af65fa05ae

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On Thu, Dec 22, 2016 at 8:59 AM, Hannes Frederic Sowa wrote: > On Thu, 2016-12-22 at 08:07 -0800, Andy Lutomirski wrote: >> On Thu, Dec 22, 2016 at 7:51 AM, Hannes Frederic Sowa >> wrote: >> > On Thu, 2016-12-22 at 16:41 +0100, Jason A.

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On Thu, 2016-12-22 at 08:07 -0800, Andy Lutomirski wrote: > On Thu, Dec 22, 2016 at 7:51 AM, Hannes Frederic Sowa > wrote: > > On Thu, 2016-12-22 at 16:41 +0100, Jason A. Donenfeld wrote: > > > Hi Hannes, > > > > > > On Thu, Dec 22, 2016 at 4:33 PM, Hannes Frederic

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On Thu, Dec 22, 2016 at 8:28 AM, Jason A. Donenfeld wrote: > Hi all, > > I don't know what your design requirements are for this. It looks like > you're generating some kind of crypto digest of a program, and you > need to avoid collisions. If you'd like to go with a PRF (keyed

Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

Hi all, I don't know what your design requirements are for this. It looks like you're generating some kind of crypto digest of a program, and you need to avoid collisions. If you'd like to go with a PRF (keyed hash function) that uses some kernel secret key, then I'd strongly suggest using

BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

On Thu, Dec 22, 2016 at 7:51 AM, Hannes Frederic Sowa wrote: > On Thu, 2016-12-22 at 16:41 +0100, Jason A. Donenfeld wrote: >> Hi Hannes, >> >> On Thu, Dec 22, 2016 at 4:33 PM, Hannes Frederic Sowa >> wrote: >> > IPv6 you cannot touch