Lepton's Crack

Lepton's Crack is a generic password cracker. It is easily-customizable with a simple plugin system and allows system administrators to review the quality of the passwords being used on their systems. It can perform a dictionary-based (wordlist) attack as well as a brute force (incremental) password scan, including the use of regular expressions. It supports standard MD4 hash, standard MD5 hash, NT MD4/Unicode, Lotus Domino HTTP password (R4), and SHA-1 hash formats. LM (LAN Manager) plus appending and prepending of characters is available in the Development branch (strongly recommended).

Tags Security Cryptography Systems Administration Utilities
Licenses GPL
Operating Systems Windows Windows Windows POSIX Linux
Implementation C

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Rss Recent releases

  • Rrelease-mid
  •  17 Sep 2004 06:49
  • Rrelease-after

Changes: REGEX enumeration when len is greater than 1 now starts with len=1 and proceeds up to max_len. Charset and REGEXes can now be saved to a text file. -stdin allows feeding lcrack from an external password generator. The mktbl program is now included to generate pre-computed hash tables (rainbow tables). LM hsa been briefly deactivated until the next version to rework it.

  • Rrelease-mid
  •  06 Jan 2003 02:14
  • Rrelease-after

Changes: This version adds a SHA-1 module.

  • Rrelease-mid
  •  18 Dec 2002 06:24
  • Rrelease-after

Changes: Several bugfixes and optimizations were made, including a minor optimization (~2%) of the Lotus Domino hash calculation. If a password was repeated in the input file, only one of them was found. This has been fixed.

  • Rrelease-mid
  •  17 Dec 2002 14:44
  • Rrelease-after

No changes have been submitted for this release.

Rss Recent comments

Rcomment-before 02 Sep 2004 16:10 Rcomment-trans lepton Rcomment-after

Mingw support

I've done a couple of changes in sha1.h, md5.c solving some compatibility problems.

Also, LCrack can now be compiled under the MINGW environment (gettimeofday() is now implemented for MingW, and %llu is replaced by %I64u -- don't worry, it's all #ifdef'd, so Unix/Linux/Cygwin works like always..)

Rcomment-before 02 Sep 2004 12:55 Rcomment-trans lepton Rcomment-after

Improvements and new features..

Hi all,

After a long time, I'm back with lcrack :)

The regex's are now enumerated in increasing-length order, and the speed penalty is very small (if you prefer the 'old' way of enumerating regex's, use the '-g#' switch instead of '-g')

I've also added a separate 'regex' program that enumerates the expression (with the 'usual' -s, -l and -g[#]) and dumps it to stdout..

I'm now also making a program called 'mktbl' that generates pre-computed tables for faster cracking. Input is stdin (one word per line), and output is a binary file suitable for use with '-xf+ -t' in lcrack. The program is already finished, but I'm testing it..

I still haven't integrated my version with Bruneti's improvements, but hopefully I'll take care of that soon..

I will shortly update the lycos site and the stuff here..

Lepton.

Rcomment-before 11 Aug 2004 02:36 Rcomment-trans nekromancer Rcomment-after

Re: Hi from Argentina!!!!!
Hi Umpy

Nice to "see" you here ;-)
Are you "still in the business"? email me privately please.
Cheers,

Nekromancer

Rcomment-before 11 Aug 2004 02:35 Rcomment-trans nekromancer Rcomment-after

Re: Can you make it faster?
Hi Erman,

I ALSO use John the Ripper when bruteforce cracking speed or password mangling is a must ;-)
I use Lepton's Crack for the features that make it unique:

a) REGEX support (see the link to the demo above)
b) Lotus Domino R4 support
c) SHA-1 support

Answering your question, the code is almost as fast as possible using pure C language (OK, someone can improve it, for sure ;-)
To make it faster, portions of it have to be coded in machine language, thus losing portability, and it's definitely not our intention to do that in the inmediate future.
Cheers,

Nekromancer

Rcomment-before 11 Aug 2004 01:55 Rcomment-trans lcheseline Rcomment-after

Hi from Argentina!!!!!
Hello Mike!

Wonderful to see that you are still active with the tool.

Greetings from one of your students @CIUA!

CU

Lord Cheseline

aka Umpy ;-)

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