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Date: Sun, 05 Apr 2015 19:16:24 +0200
From: Frank Dittrich <frank.dittrich@...lbox.org>
To: john-dev@...ts.openwall.com
Subject: Re: gpg and gpg-opencl benchmarks
Alexander,
On 04/05/2015 11:44 AM, Solar Designer wrote:
> Frank, magnum -
>
> The speeds reported by our gpg and gpg-opencl benchmarks look too high
> to me:
>
> [solar@...er run]$ export GOMP_CPU_AFFINITY=0-31
> [solar@...er run]$ ./john -te -form=gpg-opencl -dev=1
> Will run 32 OpenMP threads
> Device 1: Tahiti [AMD Radeon HD 7900 Series]
> Local worksize (LWS) 64, global worksize (GWS) 262144
> Benchmarking: gpg-opencl, OpenPGP / GnuPG Secret Key [SHA1 OpenCL]... (32xOMP)DONE
> Speed for cost 1 (iteration count) of 65536, cost 2 (hash algorithm [1:MD5 2:SHA1 3:RIPEMD160 8:SHA256 9:SHA384 10:SHA512 11:SHA224]) of 2, cost 3 (cipher algorithm [1:IDEA 2:3DES 3:CAST5 4:Blowfish 7:AES128 8:AES192 9:AES256]) of 3
> Raw: 619237 c/s real, 46098 c/s virtual
>
> 619237*65536/10^9 = 40.6 billion SHA-1/second
>
> This is way too much for one GPU in a 7990.
>
> Is this really "for cost 1 (iteration count) of 65536"? And if it is,
> why is it so fast?
>
> The --format=gpg exhibits the same problem, only with speeds lower
> according to the CPU/GPU performance difference. (So it reports speeds
> that look too high for the CPUs.)
yes you are right, thanks for noticing.
I just took my_salt->count and reported it as iteration count.
But in gpg_fmt_plug.c we have
532: n = cur_salt->count / bs;
533- while (n-- > 0) {
534- SHA1_Update(&ctx, keybuf, bs);
535- }
536: SHA1_Update(&ctx, keybuf, cur_salt->count % bs);
537- SHA1_Final(key + (i * SHA_DIGEST_LENGTH), &ctx);
577: n = cur_salt->count / bs;
578- while (n-- > 0) {
579- SHA256_Update(&ctx, keybuf, bs);
580- }
581: SHA256_Update(&ctx, keybuf, cur_salt->count % bs);
582- SHA256_Final(key + (i * SHA256_DIGEST_LENGTH), &ctx);
etc.
This needs to be fixed. Right now I really am too tired.
Frank
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