看标题就能知道这个是干什么的了吧！这个是linux下破解密码用的，早上在chinaunix上看东西，无意中发现了这个东西！与大家共享！本站不提供此软件的详细使用，心理阴暗者请不要使用。如果你的电脑被别人破解也与我无关~~~~~~~~

2009-07-24 10:57:09

ohn the Ripper is a fast password cracker, currently available for many flavors of Unix (11 are officially supported, not counting different architectures), Windows, DOS, BeOS, and OpenVMS. Its primary purpose is to detect weak Unix passwords. Besides several crypt(3) password hash types most commonly found on various Unix flavors, supported out of the box are Kerberos AFS and Windows NT/2000/XP/2003 LM hashes, plus several more with contributed patches.

地址：http://www.openwall.com/john/

安装：
1.下载之后，进入到scr目录
2.依次运行下面的三个命令
make
make clean SYSTEM
make clean generic
3.测试
进入到run目录，运行 ./john --test

使用：
john [OPTIONS] [PASSWORD-FILES]
--single "single crack" mode
--wordlist=FILE --stdin wordlist mode, read words from FILE or stdin
--rules enable word mangling rules for wordlist mode
--incremental[=MODE] "incremental" mode [using section MODE]
--external=MODE external mode or word filter
--stdout[=LENGTH] just output candidate passwords [cut at LENGTH]
--restore[=NAME] restore an interrupted session [called NAME]
--session=NAME give a new session the NAME
--status[=NAME] print status of a session [called NAME]
--make-charset=FILE make a charset, FILE will be overwritten
--show show cracked passwords
--test perform a benchmark
--users=[-]LOGIN|UID[,..] [do not] load this (these) user(s) only
--groups=[-]GID[,..] load users [not] of this (these) group(s) only
--shells=[-]SHELL[,..] load users with[out] this (these) shell(s) only
--salts=[-]COUNT load salts with[out] at least COUNT passwords only
--format=NAME force ciphertext format NAME: DES/BSDI/MD5/BF/AFS/LM
--save-memory=LEVEL enable memory saving, at LEVEL 1..3