John是一个破解系统密码的工具。
参数
John the Ripper 1.9.0-jumbo-1 OMP [linux-gnu 64-bit x86_64 AVX AC]
Copyright (c) 1996-2019 by Solar Designer and others
Homepage: http://www.openwall.com/john/
Usage: john [OPTIONS] [PASSWORD-FILES]
--single[=SECTION[,..]] "single crack" mode, using default or named rules
--single=:rule[,..] same, using "immediate" rule(s)
--wordlist[=FILE] --stdin wordlist mode, read words from FILE or stdin
--pipe like --stdin, but bulk reads, and allows rules
--loopback[=FILE] like --wordlist, but extract words from a .pot file
--dupe-suppression suppress all dupes in wordlist (and force preload)
--prince[=FILE] PRINCE mode, read words from FILE
--encoding=NAME input encoding (eg. UTF-8, ISO-8859-1). See also
doc/ENCODINGS and --list=hidden-options.
--rules[=SECTION[,..]] enable word mangling rules (for wordlist or PRINCE
modes), using default or named rules
--rules=:rule[;..]] same, using "immediate" rule(s)
--rules-stack=SECTION[,..] stacked rules, applied after regular rules or to
modes that otherwise don't support rules
--rules-stack=:rule[;..] same, using "immediate" rule(s)
--incremental[=MODE] "incremental" mode [using section MODE]
--mask[=MASK] mask mode using MASK (or default from john.conf)
--markov[=OPTIONS] "Markov" mode (see doc/MARKOV)
--external=MODE external mode or word filter
--subsets[=CHARSET] "subsets" mode (see doc/SUBSETS)
--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. It will be overwritten
--show[=left] show cracked passwords [if =left, then uncracked]
--test[=TIME] run tests and benchmarks for TIME seconds each
--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[:MAX] load salts with[out] COUNT [to MAX] hashes
--costs=[-]C[:M][,...] load salts with[out] cost value Cn [to Mn]. For
tunable cost parameters, see doc/OPTIONS
--save-memory=LEVEL enable memory saving, at LEVEL 1..3
--node=MIN[-MAX]/TOTAL this node's number range out of TOTAL count
--fork=N fork N processes
--pot=NAME pot file to use
--list=WHAT list capabilities, see --list=help or doc/OPTIONS
--format=NAME force hash of type NAME. The supported formats can
be seen with --list=formats and --list=subformats
翻译
john系统自带密码路径
/usr/share/john/password.lst
爆破过程
如果不指定字典的话，会使用john系统自带的password.lst字典
一个注意事项
john工具对于同一个shadow文件只会进行一次爆破，如果第二次执行john shadow是不会得到结果的，只会得到如下输出。
Warning: detected hash type "md5crypt", but the string is also recognized as "md5crypt-long"
Use the "--format=md5crypt-long" option to force loading these as that type instead
Using default input encoding: UTF-8
Loaded 1 password hash (md5crypt, crypt(3) $1$ (and variants) [MD5 128/128 AVX 4x3])
No password hashes left to crack (see FAQ)
如果想查看上一次爆破的结果，可以使用以下命令。
root@kali:~# john --show password
frank:frank!!!