Date: Wed, 1 Aug 2012 12:13:49 -0500 From: "jfoug" <jfoug@....net> To: <john-dev@...ts.openwall.com> Subject: RE: Output for dynamic formats in --list=format-details (and --list=format-all-details This is very easy to fix this symptom, but I think this was done this way for a reason, it is just so long ago, I cannot remember exactly what side effect changing this back would do. The problem was something like auto-detection, if the -format was not used, or in 'ability' to do something like: -test -format=dynamic, or something I actually 'think' it was in that last (ability to use -format=dynamic as a format type). This may have been more for historical compatibility than anything else. If all that it was is -format=dynamic no longer works, then I am not too concerned. The dynamic (md5_gen) format used to be a very fat format. It had only] a single format structure, and this structure would morph itself into the proper structure layout, for the exact format being used. This was pretty trivial for real cracking where only one format is 'needed'. However, it made for MANY issues. There were problems in testing/benching, problems with overflow detection, etc, etc, etc. It was a bad design. The current dynamic is now interrogated by john.c, and an array of proper format structures is returned. Each of these are 'stand alone' in that they have all the proper data for EXACTLY that one sub type. After writing this email, I am pretty sure that the code I will show (prior to the commented out lines, shown here), was done, to keep some of the older behavior, of -format=dynamic working. However, there are several bad side effect to this. One you list Frank. Others are in the multi-format detection. It will simply list 'dynamic' as one of the types, vs dynamic_0. I have tested, and -test=0 -form=dynamic does not work with the lines commented out, but does work when they are left in. I am 95% sure this 'is' the reason it was done this way. However, the side effects outweigh the benefit of allowing 'dynamic' as a format type, to mean 'all' dynamic types. We could probably still get that behavior, by making changes elsewhere, but I am not sure that is of as much usefulness as it was when I was developing dynamic. Initially, I think you could only test dynamic (md5_gen), as a whole. I do not think testing of a single format was possible, until the formats were split up into their own structures (but my memory of this may not be correct). Well, here is the change. As for jumbo-7, I would vote to NOT put this in there. Let's make SURE there are not other bad side effects before we add this to a 'normal' release. Within dynamic_fmt.c, in the LoadOneFormat() function, these lines get commented out: /* we 'have' to take the sig from the test array. If we do not have */ /* our preload array 'solid', then the idx will not be the proper */ /* number. So we simply grab the label from the test cyphertext string */ strncpy(label, pFmt->params.tests.ciphertext, 15); cp = strchr(&label, '$'); cp = 0; strcpy(label_id, &label); cp = strchr(label_id, '$'); *cp = 0; // if (!options.format || strncmp(options.format, "dynamic_", 8)) // pFmt->params.label = str_alloc_copy("dynamic"); // else pFmt->params.label = str_alloc_copy(label_id); strcpy(curdat.dynamic_WHICH_TYPE_SIG, label); curdat.dynamic_HASH_OFFSET = strlen(label); Jim. >From: Frank Dittrich [mailto:frank_dittrich@...mail.com] > >Currently, format label is always printed as "dynamic". >Should this be changed to "dynamic_N", where N is the dynamic format >number. > >I think this would be better, but I wanted to ask what others think. >If we change this, should this be changed for 1.7.9-jumbo-6-fixes as >well? > >I posted this to john-dev instead of john-users, because I think most >users don't care, but people developing scripts of other software using >john's output do care.
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