Date: Tue, 16 Jul 2013 18:38:52 +0400 From: Solar Designer <solar@...nwall.com> To: john-dev@...ts.openwall.com Subject: Re: Parallella: bcrypt Katja, On Tue, Jul 16, 2013 at 03:12:02PM +0200, Katja Malvoni wrote: > Self test - 822 c/s, with password.lst and pw-fake-unix 01:49:18, 820.9 > c/s, 3059 password hashes cracked, 9531 left (Loaded 3107 password hashes > with 3107 different salts) Somehow you were computing the full bcrypt output (184 data bits) on Epiphany, yet checking only 32 bits of it. I've just tried patching it to compute 64 bits, and check 64 bits. The speed appears to have improved slightly, to 825 c/s. Ideally, we'd also be computing and checking the rest of bcrypt output in cmp_exact() - on the host CPU. (It is OK to recompute the entire bcrypt on host in those rare cases.) 64 bits is good enough for now, though. (32 bits was a bit low, with non-negligible risk of false positives.) I've attached my patch/hack implementing the 64-bit computation and comparison. Also, I tried running on $2a$05 vs. $2a$10. Here's the speed I get for the latter: solar@...aro-ubuntu-desktop:~/k/run$ wc -l w 1024 w solar@...aro-ubuntu-desktop:~/k/run$ cat pw10 $2a$10$./1QQaaGve.s2ZffTVGcDOXIWLLoVbZeGuXXUQKOt8ixJMmU.y7O. solar@...aro-ubuntu-desktop:~/k/run$ ./parallella_john.sh -form=bcrypt-parallella -w=w pw10 Loaded 1 password hash (bcrypt-parallella, OpenBSD Blowfish [Parallella]) Press 'q' or Ctrl-C to abort, almost any other key for status 0g 0:00:00:34 100% 0g/s 29.68p/s 29.68c/s 29.68C/s pinkfloyd..raptor Session completed 825/29.68/32 = 87% efficiency So you might be able to make things up to 13% faster by optimizing the communication, as well as code outside of the inner loop. Alexander View attachment "john-parallella-bcrypt-64bit.diff" of type "text/plain" (2123 bytes)
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