At exam Lab example.com domain resides on 172.24.0.0/16 Network and my133t.org resides on 172.25.0.0/16 Network.

1. vi /etc/squid/squid.conf

#detault:

http_port 8080

#Recommended minimum configuration:

# Near the src acl src section

acl allownet src 172.24.0.0/255.255.0.0

acl denynet src 172.25.0.0/255.255.0.0

#Default:

# http_access deny all

#Under Here http_access allow allownet

http_access deny denynet

2. service squid start

3. chkconfig squid on

squid is a proxy caching server, using squid we can share the internet, block the internet, to certain network. First we should define the port for squid, the standard port for squid is 3128. We can run squid on different port by specifying http_port portnumber.

Do the following steps as:

1. vi /etc/security/limits.conf

user1 hard nproc 7

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

session required /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.

Do the following steps as:

1 . vi /etc/hosts.deny

vsftpd:ALL EXCEPT .example.com

or

1. vi /etc/hosts.deny

vsftpd:ALL

2. vi /etc/hosts.allow

vsftpd:.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.

Do the following steps as:

1. vi /etc/samba/smb.conf

[global]

netbios name=station?

workgroup=station?

security=user

smb passwd file=/etc/samba/smbpasswd

encrypt passwords=yes

hosts allow= .example.com

[data]

path=/storage

public=no

writable=no

write list=harold

browsable=yes

2. smbpasswd -a harold

3. service smb start

4. chkconfig smb on

/etc/samba/smb.conf. There are some pre-defined section, i. global  use to define the global options, ii. Printers  use to share the printers, iii. homes  use the share the user’s home directory.

Security=user  validation by samba username and password. May be there are other users also. To allow certain share to certain user we should use valid users option.

smbpasswd  Helps to change user’s smb password. –a option specifies that the username following should be added to the local smbpasswd file.

If any valid users option is not specified, then all samba users can access the shared data. By Default shared permission is on writable=no means read only sharing. Write list option is used to allow write access on shared directory to certain users or group members.

Do the following steps as:

1. vi /etc/httpd/conf/httpd.conf

< VirtualHost 192.100.0.1 >

ServerName www.abc.com

DocumentRoot /var/www/abc/

< Directory /var/www/abc >

AllowOverride authconfig

< /Directory >

DirectoryIndex index.html

ServerAdmin webmaster@abc.com

ErrorLog logs/error_abc.logs

CustomLog logs/custom_abc.logs common

< /VirtualHost >

2. Create the directory and index page on specified path. (Index page can download from ftp://server1.example.com at exam time)

Check the SELinux context of index.html file, should be like this:

-rw-r--r-- root root system_u:object_r:httpd_sys_content_t /var/www/html/index.html

If SELinux Context is mismatched, use the restorecon –R /var command

3. vi /var/www/abc/.htaccess

AuthName “Only to Authorized Users”

AuthType basic

AuthUserFile /etc/httpd/conf/mypasswd

require valid-user

Check the SELinux Context, should like this:

-rw-r--r-- root root root:object_r:httpd_sys_content_t .htaccess

htpasswd –c /etc/httpd/conf/mypasswd user5

htpasswd –m /etc/httpd/conf/mypasswd user6

chgrp apache /etc/httpd/conf/mypasswd

chmod g+r /etc/httpd/conf/mypasswd

Check the SELinux Context, should like this:

-rw-r--r-- root root system_u:object_r:httpd_config_t /etc/httpd/conf/mypasswd

Use restorecon command to restore the mismatched SELinux Context of the file.

service httpd restart

chkconfig httpd on

AllowOverride Authconfig is used to specify which and how much configuration can be overridden by directory specific .htaccess files.

One of the most common tasks performed in users’ .htaccess files is adding authorization. Typically, a user will setup authorization for directories that hold sensitive information with a configuration.

Do the following steps as:

1. vi /etc/samba/smb.conf

[global]

netbios name=station?

workgroup=station?

security=user

smb passwd file=/etc/samba/smbpasswd

encrypt passwords=yes

hosts allow= .example.com

[data]

path=/data

public=no

writable=no

browsable=yes

2. smbpasswd -a jeff

3. service smb start

4. chkconfig smb on

/etc/samba/smb.conf. There are some pre-defined section, i. global  use to define the global options, ii. Printers  use to share the printers, iii. homes  use the share the user’s home directory.

Security=user  validation by samba username and password. May be there are other users also. To allow certain share to certain user we should use valid users option.

smbpasswd  Helps to change user’s smb password. –a option specifies that the username following should be added to the local smbpasswd file.

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 required pam_securetty.so

auth required pam_stack.so service=system-auth

auth required pam_nologin.so

account required pam_stack.so service=system-auth

password required pam_stack.so service=system-auth

# pam_selinux.so close should be the first session rule

session required pam_selinux.so close

session required pam_stack.so service=system-auth

session optional pam_console.so

# pam_selinux.so open should be the last session rule

session required pam_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/limits.conf

user1,user2 - maxlogins 1

@training - maxlogins 5

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

session required /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.

Do the following steps as:

1. vi /etc/hosts.deny

ALL:.cracker.org EXCEPT trusted.cracker.org

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.

Do the following steps as:

1. vi /etc/hosts.deny

sshd:ALL EXCEPT .example.com: spawn echo “Loging attempt from %c to %s” | mail –s “Login from denied hosts” root

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.