Re: memxor

[Simon Josefsson]

Bruno Haible <address@hidden> writes:

> Hello Nikos,
>
>> > Can you tell me
>> > one program which spends more than 20% of its runtime in memxor?
>> 
>> I had 10% speed-ups in a web server that used gnutls with the optimized
>> version of memxor. That is because CBC encryption mode uses XOR heavily.
>> 10% is enormous speed-up considering that this is a very small part of
>> the encryption process.
>
> OK, that is sufficient rationale for having this faster memxor function in
> gnutls.
>
> The next question, also to Simon, is whether you want to have the faster
> memxor only in gnutls and leave the slower but simpler one in gnulib
> (used by the modules crypto/*hmac-* only). Or whether you want to have the
> faster one in gnulib.

I'm surprised the gnulib memxor ends up being used by GnuTLS at all.
Nikos, shouldn't the Nettle implementation be used instead?  Is this a
question of the GnuTLS (gnulib) memxor symbol replacing the memxor that
is shipped with Nettle?  Maybe the solution is to fix the Nettle
namespace.

/Simon