Pass Using RH302 Exam Dumps

Do the following steps as:

1.touch /etc/nologin

2.vi /etc/securetty

comment all available terminall then first.

If /etc/nologin file is created, then pam modules pan_nologin deny to all non-root users to login locally.

/etc/pam.d/login file calls the module.

#%PAM-1.0

auth requiredpam_securetty.so

auth requiredpam_stack.so service=system-auth

auth requiredpam_nologin.so

account requiredpam_stack.so service=system-auth

password requiredpam_stack.so service=system-auth

# pam_selinux.so close should be the first session rule

session requiredpam_selinux.so close

session requiredpam_stack.so service=system-auth

session optionalpam_console.so

# pam_selinux.so open should be the last session rule

session requiredpam_selinux.so multiple open

pam_securetty modules checks the /etc/securetty file, which terminal are available to root. If terminal is not available in this file then pam_securetty module deny to login on unavailable terminal to root user.

Do the following steps as:

1.vi /etc/security/time.conf

login;*;user9|user10;SuMoFri1200-1400

2.vi /etc/pam.d/login

accountrequiredpam_time.so

For Time based authentication, we should configured in /etc/security/time.conf

Syntax of /etc/security/time.conf

services;ttys;users;times

services

is a logic list of PAM service names that the rule applies to.

ttys

is a logic list of terminal names that this rule applies to.

users

is a logic list of users to whom this rule applies.

times

the format here is a logic list of day/time-range entries the days are specified by a sequence of two character entries, MoTuSa for example is Monday Tuesday and Saturday. Note that repeated days are unset MoMo = no day, and MoWk = all weekdays bar Monday. The two character combinations accepted are

Mo Tu We Th Fr Sa Su Wk Wd Al

the last two being week-end days and all 7 days of the week respectively. As a final example, AlFr means all days except Friday.

pam_time modules checks the file /etc/security/time.conf for authentication. So, we should call the pam_time modules in /etc/pam.d/login.

Do the following steps as:

1.vi /etc/hosts.deny

sshd:ALL EXCEPT .example.com

or

1.vi /etc/hosts.deny

sshd:ALL

2.vi /etc/hosts.allow

sshd:.example.com

We can secure the services using tcp_wrappers. There are main two files, /etc/hosts.allow and /etc/hosts.deny.

There will be three stage access checking

- Is access explicitly permitted? Means permitted from /etc/hosts.allow?

- Otherwise, Is access explicitly denied? Means denied from /etc/hosts.deny?

- Otherwise, by default permit access if neither condition matched.

To deny the services we can configure /etc/hosts.deny file using ALL and EXCEPT operation. Pattern of /etc/hosts.allow and /etc/hosts.deny file is:

Demon_list:client_list:options

In Client list can be either domain name or IP address.

Note: In Exam Lab there will be two different domain example.com which is known as local domain and another is cracker.org which is called non trusted domain. So only from .example.com means allow only to example.com deny to every one.

Do the following steps as:

1.vi /etc/security/limits.conf

user1hardnproc7

2.vi /etc/pam.d/system-auth

sessionrequired/lib/security/pam_limits.so

To limit the number of process or number of logins, we should configure on /etc/security/limits.conf. First Columns contains the username separated by comma or @group name. Second column either hard or soft limits. Third columns called the item, maxloigns or nproc etc.

To identify the session of users we should call the pam_limits module in /etc/pam.d/system-auth.