Shell scripts for Auditing and automating the process

[ShivKumar_1]

Each system must generate a security alaram by which to alert the
administrator of a potential security or
suspicious activity Eg: High volumes of bad packet data or corrupted
data.
The alarm must be activated by the following events

1) Five consecutive unsucessful login attempts during a single session
2) Sucessful modification of critical system or application files
3) Sucessful and unsucessful attempts to gain permission or assume
identitiy
of another user
4) Upon sucessful login the system must display the date and time of
last
sucessful logins
5) Each system must maintain a list of security files which is
accesible by
the administrator of the following events

a) Sucessful and unsucessful events
b) Sucessful and unsucessful attempts to switch to another user's
account
c) All changes to system security ,including adding users
d) Operating system configuration changes
e) Logoffs
f) Inactive user sessions

6) Disabling inactive userids which were inactive for more than 15 days
7) No reuse of the same password used in the past

[Rick Garland · Accepted solution]

Some of the tasks you mentioned can be performed by Tripwire.

[ShivKumar_1]

I cannot use a third party software like TRIPWARE as my client doest allow it , everything has to be automated by shell scripts