The/etc/password&&/etc/shadow learning record of Linux

/etc/passwd

Root?0:0:root:/root:/bin/bash
Daemon?1:1:daemon:/usr/sbin:/bin/sh
Bin?2:2:bin:/bin:/bin/sh
Sys?3:3:sys:/dev:/bin/sh

Root:x: 0:0: Root:/root:/bin/bash
Name: Password: User id: Group ID: User information: Home directory: Shell

Some default accounts can be used to confuse the administrator:

ADM has account files, starting directory/var/adm usually includes log files
Bin has an executable file with user commands
Daemon used to perform the system daemon
Games used to play the game
Halt used to execute halt commands
LP has printer spool file
Mail has processes and files associated with the message
News has processes and files related to Usenet
Nobody is used by NFS (Network File system)
Shutdown Execute shutdown command
Sync Run sync command
UUCP has UUCP tools and files

/etc/shadow

It pwconv is automatically generated by the command according to the data in the/etc/passwd
Root:$6$8zqdahkb$xyr1l9ep26x1ihp6boaigu7qo1entsyfxtu6hhvmdqmrgfxkhj/ltkgaywqa45ps/2htf6sai/6gzle7sf6kr1 : 16538:0:99999:7:::

Login: Password: The number of days the password was last modified: two the minimum number of days to modify a password: The maximum number of days that a password can be saved: a few days before password change warning:::
The next three are usually not.

$6$8zQdAHKB$xYr1l9EP26x1IhP6bOAigu7qO1ENtsyfxtU6hHvMdQMrgfxKhJ/ltkgAYwqA45ps/2HTF6saI/6gzLe7sF6kr1

$id $salt $ redaction
Where the value of the ID is the type of algorithm that corresponds to the encryption:

1:MD5 (22-bit)
2a:blowfish, encryption methods that are used only in a subset of the Linux branches
5:SHA-256 (43-bit)
6:SHA-512 (86-bit)

Encrypt with salt, then generate [a–za–z0–9./] range of characters as ciphertext

(John) Brute force

Export the current system's password file
Unshadow/etc/passwd/etc/shadow > MYPASSWD
Simple hack
John MYPASSWD

root:$6$8zqdahkb$xyr1l9ep26x1ihp6boaigu7qo1entsyfxtu6hhvmdqmrgfxkhj/ltkgaywqa45ps/2htf6sai/6gzle7sf6kr1:0:0: Root:/root:/bin/bash

Parameter description:

--fork=30       30线程--single        简单模式--wordlist=password.lst     字典模式--incremental       穷举--show password.txt 查看破解成功的 --format=des/bsdi/md5/bf/afs/lm/trip/dummy 多种破解类型可供选择--restore 存放当前解密进度--test 测试当前机器解密速度--users 只破解某类型用户--list 屏幕输出正在破解的密码

The/etc/password&&/etc/shadow learning record of Linux