From: Herbert Xu Subject: Re: [RFC PATCH 4.10 0/6] Switch BPF's digest to SHA256 Date: Mon, 26 Dec 2016 16:20:58 +0800 Message-ID: <20161226082058.GA9013@gondor.apana.org.au> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: daniel@iogearbox.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, Jason@zx2c4.com, hannes@stressinduktion.org, alexei.starovoitov@gmail.com, edumazet@google.com, ebiggers3@gmail.com, tom@herbertland.com, davem@davemloft.net, luto@kernel.org To: Andy Lutomirski Return-path: Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org Andy Lutomirski wrote: > Since there are plenty of uses for the new-in-4.10 BPF digest feature > that would be problematic if malicious users could produce collisions, > the BPF digest should be collision-resistant. SHA-1 is no longer > considered collision-resistant, so switch it to SHA-256. > > The actual switchover is trivial. Most of this series consists of > cleanups to the SHA256 code to make it usable as a standalone library > (since BPF should not depend on crypto). > > The cleaned up library is much more user-friendly than the SHA-1 code, > so this also significantly tidies up the BPF digest code. > > This is intended for 4.10. If this series misses 4.10 and nothing > takes its place, then we'll have an unpleasant ABI stability > situation. Can you please explain why BPF needs to be able to use SHA directly rather than through the crypto API? Thanks, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt