Nmap Development mailing list archives
Re: New hexdump() function for nbase/nmap
From: David Fifield <david () bamsoftware com>
Date: Tue, 25 Aug 2009 10:07:44 -0600
On Tue, Aug 25, 2009 at 11:41:20AM +0100, Luis M. wrote:
Nmap currently uses two functions to dump hex bytes to stdout. One of them, hdump(), just prints raw hex bytes (no ASCII equivalents) and the other one, lamont_hdump() has a bug when printing buffers where bufflen%16==3. I've just implemented a new version from scratch, hopefully bug-free, that basically produces the same output as Wireshark. Output looks like this: 0000 e8 60 65 86 d7 86 6d 30 35 97 54 87 ff 67 05 9e .`e...m05.T..g.. 0010 07 5a 98 c0 ea ad 50 d2 62 4f 7b ff e1 34 f8 fc .Z....P.bO{..4.. 0020 c4 84 0a 6a 39 ad 3c 10 63 b2 22 c4 24 40 f4 b1 ...j9.<.c.".$@.. I attach two patches. One of them includes the new function into nbase and the other one replaces calls to the old functions in nmap's code. Can some of you guys, please have a look at the patches, so I have a second opinion before applying them. Thanks.
Keeping a buffer of a whole line is a good idea. The code looks correct but to me it's a bit hard to understand. I suggest a loop structure that mirrors the output: one line at a time, each line of 16 bytes. Like this: i = 0; while (i < length) { fill line with spaces add line number do { if (i % 16 == 8) add space add hex of cp[i] add ascii of cp[i] i++ } while (i < length && i % 16 != 0); copy line to output } The cp parameter should be const. Why are there 257, not 256, elements in the asciify array? Nothing is ever stored or read from the final element. David Fifield _______________________________________________ Sent through the nmap-dev mailing list http://cgi.insecure.org/mailman/listinfo/nmap-dev Archived at http://SecLists.Org
Current thread:
- New hexdump() function for nbase/nmap Luis M. (Aug 25)
- Re: New hexdump() function for nbase/nmap David Fifield (Aug 25)
- Re: New hexdump() function for nbase/nmap Luis M. (Aug 25)
- Re: New hexdump() function for nbase/nmap David Fifield (Aug 25)
- Re: New hexdump() function for nbase/nmap Luis M. (Aug 25)
- Re: New hexdump() function for nbase/nmap Luis M. (Aug 25)
- Re: New hexdump() function for nbase/nmap David Fifield (Aug 25)