Explaining The Process - Red Hat ENTERPRISE LINUX 3 System Administration Manual

Chapter 35. User and Group Configuration
3. Unlock the account — There are two common approaches to this step. The administrator can
assign an initial password or assign a null password.
Warning
Do not use the
expiration just configured.
To assign an initial password, use the following steps:
Start the command line Python interpreter with the
•
ing:
Python 2.2.2 (#1, Dec 10 2002, 09:57:09)
[GCC 3.2.1 20021207 (Red Hat Enterprise Linux 3 3.2.1-2)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>
At the prompt, type the following (replacing password with the password to encrypt and
•
salt with a combination of exactly 2 upper or lower case alphabetic characters, digits, the
dot (.) character, or the slash (/) character such as
import crypt; print crypt.crypt("password","salt")
The output is the encrypted password similar to
Type [Ctrl]-[D] to exit the Python interpreter.
•
Cut and paste the exact encrypted password output, without a leading or trailing blank spaces,
•
into the following command:
usermod -p "encrypted-password" username
Instead of assigning an initial password, a null password can be assigned using the command:
usermod -p "" username
Caution
While using a null password is convenient for both the user and the administrator, there is a
slight risk that a third party can log in first and access the system. To minimize this threat, it is
recommended that the administrator verifies that the user is ready to log in when the account
is unlocked.
In either case, upon initial log in, the user is prompted for a new password.

35.6. Explaining the Process

The following steps illustrate what happens if the command
that has shadow passwords enabled:
1. A new line for
It begins with the username
•
There is an
• x
A UID at or above 500 is created. (Under Red Hat Enterprise Linux, UIDs and GIDs below
•
500 are reserved for system use.)
A GID at or above 500 is created.
•
The optional GECOS information is left blank.
•
The home directory for
•
command to set the password as it disables the immediate password
passwd
is created in
juan /etc/passwd
juan
for the password field indicating that the system is using shadow passwords.
is set to
juan
python
or
ab
12CsGd8FRcMSM
useradd juan
. The line has the following characteristics:
.
.
/home/juan/
command. It displays the follow-
:
12
.
is issued on a system
247