Linux加固常用记录

Linux加固常用记录
#设置密码复杂度

shell操作：

if [ -z "`cat /etc/pam.d/system-auth | grep -v "^#" | grep "pam_cracklib.so"`" ];then

sed -i '/password    requisite    pam_pwquality.so try_first_pass local_users_only retry=3 authtok_type=/i\password    required      pam_cracklib.so  try_first_pass minlen=8 ucredit=-1  lcredit=-1  ocredit=-1 dcredit=-1 retry=3 difok=4' /etc/pam.d/system-auth

fi

参数解释：

retry=3

修改密码的时候，可以重试的次数

difok=4

与旧密码不同的字符个数

minlen=8

新密码最小长度

这里记住一类就是大于0 也就是正数表示配置要求的个数最多只能有几个，相反如果是小于0，也就是负数表示配置要求的个数最少要有几个

dcredit=-1

表述设置密码的时候数字的个数必须至少含有一个

ucredit=-1

表述设置密码的时候大写字母个数必须至少含有一个

lcredit=-4

表述设置密码的时候小写字母个数必须至少含有一个

ocredit=-1

表述设置密码的时候特殊字符个数必须至少含有一个

#修改密码时效

sed -i '/PASS_WARN_AGE/s/7/10/' /etc/login.defs

sed -i '/PASS_MIN_LEN/s/5/8/' /etc/login.defs

sed -i '/PASS_MIN_DAYS/s/0/6/' /etc/login.defs

#设置操作超时锁定

if [ -z "`cat /etc/profile | grep -v "^#" | grep TMOUT`" ];then

echo -e "\nexport TMOUT=1800" >> /etc/profile

fi

#检查密码重复使用次数

if [ -z "`cat /etc/pam.d/system-auth | grep password | grep remember`" ];then

sed -i '/password    sufficient    pam_unix.so/s/$/& remember=5/' /etc/pam.d/system-auth

fi



#!/bin/bash

#设置密码复杂度

if [ -z "`cat /etc/pam.d/system-auth | grep -v "^#" | grep "pam_cracklib.so"`" ];then

sed -i '/password    requisite     pam_pwquality.so try_first_pass local_users_only retry=3 authtok_type=/i\password    required      pam_cracklib.so  try_first_pass minlen=8 ucredit=-1   lcredit=-1   ocredit=-1 dcredit=-1 retry=3 difok=4' /etc/pam.d/system-auth

fi

#设置操作超时锁定

if [ -z "`cat /etc/profile | grep -v "^#" | grep TMOUT`" ];then

echo -e "\nexport TMOUT=1800" >> /etc/profile

fi

#检查密码重复使用次数

if [ -z "`cat /etc/pam.d/system-auth | grep password | grep remember`" ];then

sed -i '/password    sufficient    pam_unix.so/s/$/& remember=5/' /etc/pam.d/system-auth

fi

#修改密码时效

sed -i '/PASS_WARN_AGE/s/7/10/' /etc/login.defs

sed -i '/PASS_MIN_LEN/s/5/8/' /etc/login.defs

sed -i '/PASS_MIN_DAYS/s/0/6/' /etc/login.defs



PASS_MAX_DAYS　　  90  --> 密码有效天数，最长多久要变更密码

PASS_MIN_DAYS　　　1    --> 密码变更后，最快多久才能再次修改密码

PASS_MIN_LEN　　　　8    --> 密码的最小设定长度

PASS_WARN_AGE   　  7    --> 密码失效之前几天发出警告信息。



#设置连续登录失败暂锁机制

if [ -z "`cat /etc/pam.d/system-auth | grep -v "^#" | grep "pam_tally.so"`" ];then

if [ -z "`cat /etc/pam.d/system-auth | grep -v "^#" | grep "pam_tally.so" | grep auth`" ];then

sed -i '/auth   include system-auth/a\auth        required      pam_tally.so deny=5 unlock_time=600 even_deny_root root_unlock_time=600' /etc/pam.d/system-auth

fi

if [ -z "`cat /etc/pam.d/system-auth | grep -v "^#" | grep "pam_tally.so" | grep account`" ];

then

sed -i '/account    include      system-auth/a\account    required      pam_tally.so' /etc/pam.d/system-auth

fi

fi

if [ -z "`cat /etc/pam.d/sshd | grep -v "^#" | grep "pam_tally.so"`" ];then

if [ -z "`cat /etc/pam.d/sshd | grep -v "^#" | grep "pam_tally.so" | grep auth`" ];then

sed -i '/auth        required      pam_deny.so/a\auth        required      pam_tally.so deny=5 unlock_time=600 even_deny_root root_unlock_time=600' /etc/pam.d/sshd

fi

if [ -z "`cat /etc/pam.d/sshd | grep -v "^#" | grep "pam_tally.so"` | grep account" ];then

sed -i '/account    required      pam_unix.so/a\account required pam_tally.so' /etc/pam.d/sshd

fi

fi



auth required pam_tally2.so deny=3 unlock_time=5 even_deny_root root_unlock_time=300

         ①-even_deny_root ###除限制普通用户外，也限制root用户

         ②-deny ###设置普通用户和root用户连续错误登录的最大次数，超过最大次数，则锁定改用户

         ③-unlock_time ###设置普通用户锁定后，多少时间后解锁，单位是秒，建议为5分钟，300秒

         ④-root_unlock_time 设置root用户锁定后，多少时间解锁，单位是秒

如果不限制root用户，则可以写成

auth required pam_tally2.so deny=3 unlock_time=300



添加密码复杂度：

sudo sed -i '/password required pam_deny.so/a\password required pam_cracklib.so try_first_pass minlen=8 ucredit=-1 lcredit=-1 ocredit=-1 dcredit=-1 retry=3 difok=5' /etc/pam.d/system-auth

修改密码时效：

sed -i '/PASS_WARN_AGE/s/7/10/' /etc/login.defs

sed -i '/PASS_MIN_LEN/s/5/8/' /etc/login.defs

sed -i '/PASS_MAX_DAYS/s/99999/90/' /etc/login.defs

sed -i '/PASS_MIN_DAYS/s/0/1/' /etc/login.defs



添加ssh登录失败锁定：

cat /etc/pam.d/sshd

#%PAM-1.0

auth      required    pam_tally2.so deny=3 unlock_time=600 even_deny_root root_unlock_time=600

auth      required    pam_sepermit.so

auth      substack    password-auth

auth      include      postlogin

# Used with polkit to reauthorize users in remote sessions

-auth      optional    pam_reauthorize.so prepare

account    required    pam_nologin.so

account    include      password-auth

password  include      password-auth

# pam_selinux.so close should be the first session rule

session    required    pam_selinux.so close

session    required    pam_loginuid.so

# pam_selinux.so open should only be followed by sessions to be executed in the user context

session    required    pam_selinux.so open env_params

session    required    pam_namespace.so

session    optional    pam_keyinit.so force revoke

session    include      password-auth

session    include      postlogin

# Used with polkit to reauthorize users in remote sessions

-session  optional    pam_reauthorize.so prepare

密码登录失败锁定推荐：

http://blog.itpub.net/31559985/viewspace-2674030/