Date: Sun, 16 Oct 2011 23:11:15 +0200 From: Jérôme Loyet <ml@...bsd.com> To: john-users@...ts.openwall.com Subject: filter performances Hi guys, I'm new to jtr and I'm facing some performance problems (I think we all do somehow) I have a single traditional DES password to bruteforce. I know its policy: 8 characters long (or more) and it uses at least one lower case, one upper case, one numerical and one "other" char. If I'm bruteforcing using the mode All (with a fixed 8 chars len) I have 95^8 = 6634204312890625 possibilities I want to reduce the number of tries as I know the policy. I have 95^4*26*26*33*10 = 18170005425000 possibilities I'm using OpenMPI to parralize to 2 servers (16 cores each) and I can compute around 40387K combinations per sec. Which means the following ETA for trying all the passwords 6634204312890625 / 40387000 / 60 / 60 / 24 = 1901 days 18170005425000 / 40387000 / 60 / 60 / 24 = 5 days The first case cannot be considered :) But the second case is far more easy to considered To filter the password not corresponding to the policy, I've tried to apply a filter similar to the optimized one described in http://www.openwall.com/lists/john-users/2009/10/28/11 But the performances are horrible. Here is a small benchmark (one single john instance is running - aka one core, one server): [root@...xxx run]# ./john -i:All8 --external=test --session=test pass.txt Loaded 1 password hash (Traditional DES [128/128 BS SSE2-16]) guesses: 0 time: 0:00:00:16 0.00% c/s: 5733 trying: cow_ie2M - cadry S9 guesses: 0 time: 0:00:01:26 0.00% c/s: 36918 trying: ccosh-L3 - ccohB#40 guesses: 0 time: 0:00:03:22 0.00% c/s: 59465 trying: 5991Br9$ - 5975Bic* guesses: 0 time: 0:00:04:45 0.00% c/s: 65719 trying: drculA$0 - ducht-L7 guesses: 0 time: 0:00:09:07 0.00% c/s: 69311 trying: pduth1A# - pdul2#A4 guesses: 0 time: 0:00:20:35 0.00% c/s: 85975 trying: 3dygut N - 3dygkb-F guesses: 0 time: 0:00:26:28 0.00% c/s: 86144 trying: 5myaf0$K - 5myon St [root@...xxx run]# ./john -i:All8 --session=test pass.txt Loaded 1 password hash (Traditional DES [128/128 BS SSE2-16]) ... c/s is constant around 2408k guesses: 0 time: 0:00:00:53 0.00% c/s: 2408K trying: 323akbab - 323agemc Without filter I can compute 2408K and with the filter enabled the computation rate is much lower. (And I don't understand why the c/s is increasing and then stall). Is there a way to achieve my goal with the same performances ? thx a lot ++ fat PS: I'm using john-1.7.8-jumbo-7
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