Re: [PATCH net-next v5 02/20] zinc: introduce minimal cryptography library
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: 2018-09-25 14:29:22
Also in:
linux-crypto, lkml
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: 2018-09-25 14:29:22
Also in:
linux-crypto, lkml
Hey Arnd, On Tue, Sep 25, 2018 at 9:18 AM Arnd Bergmann [off-list ref] wrote:
I think I misread your earlier sentence and thought you had said the exact opposite. For confirmation, I've downloaded your git tree and built it with my collection of compilers (gcc-4.6 through 8.1) and tried building it in various configurations. Nothing alarming stood out, the only thing that I think would might warrant some investigation is this one: lib/zinc/curve25519/curve25519-hacl64.h: In function 'curve25519_generic': lib/zinc/curve25519/curve25519-hacl64.h:785:1: warning: the frame size of 1536 bytes is larger than 500 bytes [-Wframe-larger-than=] Without KASAN, this takes 832 bytes, which is still more than it should use from a look at the source code. I first suspected some misoptimization around the get/put_unaligned_le64() calls, but playing around with it some more led me to this patch:
Excellent detective work. Thanks for spotting that before I had a time to respond here. I'll also send that same fix to the HACL* team at INRIA, so they can add it as a heuristic. Jason