[lkml]   [2018]   [Sep]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH net-next v5 09/20] zinc: Poly1305 ARM and ARM64 implementations
Hi Eric,

On Wed, Sep 19, 2018 at 12:55 AM Eric Biggers <> wrote:
> This will compute the wrong digest if called with simd_context=HAVE_FULL_SIMD
> and then later with simd_context=HAVE_NO_SIMD, since poly1305_blocks_neon()
> converts the accumulator from base 32 to base 26, whereas poly1305_blocks_arm()
> assumes it is still in base 32. Is that intentional? I'm sure this is a rare
> case, but my understanding is that the existing crypto API doesn't preclude
> calling successive steps in different contexts. And I'm concerned that it could
> be relevant in some cases, e.g. especially if people are importing a hash state
> that was exported earlier. Handling it by silently computing the wrong digest
> is not a great idea...

Indeed you're right; Samuel and I were just discussing that recently.
I'd rather handle this correctly even if the contexts change, so I'll
see if I can fix this up properly for that unlikely case in the next


 \ /
  Last update: 2018-09-19 02:18    [W:0.085 / U:3.552 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site