passwd(1) General Commands Manual passwd(1)
NAME
passwd, chfn, chsh - Changes password file information
SYNOPSIS
passwd [-f | -s] [username]
passwd -q [username]
passwd -q -a
chfn [username]
chsh [username]
This security-sensitive command uses the SIA (Security Integration Architecture) routine as an interface to the security mechanisms. See
the matrix.conf(4) reference page for more information.
OPTIONS
Report the password attributes of all users. This option may only be used with the -q option and you must be root. Invokes the chfn com-
mand when given with the passwd command. Report the password attributes of the specified user. If the -a option is given, all users are
listed. Users other than root may only use the -q option on themselves. If a username is not specified, then the current username is used.
Invokes the chsh command when given with the passwd command.
DESCRIPTION
The passwd command changes (or installs) the password associated with your username (by default) or the specified username.
The chfn command changes the finger information in the GECOS field associated with your username or the specified username. GECOS is an
obsolete term, but refers to the finger information field of the passwd structure as defined in the <pwd.h> file and the finger information
field of the /etc/passwd file as described in the passwd(4) reference page. The information in the GECOS field has been formalized by
POSIX and is a comma separated list containing the user's full name, office phone, office number, and home phone number.
The chsh command changes the login shell of your username or of the specified username.
When using the passwd command to alter a password, the command prompts for the current password and then for the new one. The caller must
supply both. The new password must be typed twice to forestall mistakes.
Each password must have at least six characters and can include digits, symbols, and the letters of your alphabet. It is strongly suggested
that you include unusual punctuation, control characters, or digits in your password. Use of only lowercase letters is discouraged. If you
enter more than eight characters when creating a password, the passwd command ignores any characters after the eighth.
When the -q option is used, the output of the passwd command under base security is as follows: name status
The status is "PS" if the user has a password, "LK" if the user has an administrative lock, or "NP" if the user has no password.
Under enhanced security the passwd -q command gathers information from the enhanced security password and system defaults databases and
presents the data as follows: name status date min_change max_change
The status field is "PS" if the user has a password, "LK" if the user has an administrative lock, or "NP" if the user has no password. The
date is the day of the last successful password change in mm/dd/yy format. The min_change field is the period in days, measured from the
date of last password change, which must pass before a user can change his user account password. A value of 0 means the password may be
changed at any time. The max_change field is the period in days, measured from the date of last password change, for which the password is
valid. Adding this value to the date of last password change gives the date at which the password expires and a change will be required. A
value of 0 means that the password will never expire.
When altering the GECOS information field, the chfn command displays the current information, broken into fields, as interpreted by the
finger program, among others, and prompts for new values. These fields include a user's proper name, office room number, office phone num-
ber, and home phone number. Included in each prompt is a default value, which is enclosed in [ ] (brackets). The default value is
accepted simply by pressing <Return>. To enter a blank field, the word none can be entered.
The chfn command allows phone numbers to be entered with or without dashes. It is a good idea to run finger after changing the GECOS
information to make sure everything is set up properly.
A superuser can change anyone's GECOS information; other users can only change their own. Superusers can also run the account management
interfaces, dxaccounts and usermod to modify passwords.
When altering a login shell, the chsh command displays the current login shell and then prompts for the new one. The new login shell must
be one of the approved shells listed in the /etc/shells file unless you have superuser privileges. If the /etc/shells file does not exist,
the only shells that can be specified are /usr/bin/sh and /usr/bin/csh.
Note that if you specify an abbreviated shell name, the command chooses the first entry in the /etc/shells file that matches the shell
abbreviation. For example, if you specify ksh, and both the /bin/ksh and /usr/bin/ksh shells are included in the /etc/shells file, the
shell is changed to the shell that is specified first.
A superuser can change anyone's login shell; normal users can only change their own login shell.
Security Note
When you use the passwd command, with enhanced security installed, the system prompts for the existing password, and begins a password
solicitation dialog that depends on the options for password generation the administrator has enabled for your account. There are four
possible options: A pronounceable password made up of meaningless syllables. An unpronounceable password made up of random characters from
the character set. An unpronounceable password made up of random letters from the alphabet. A user specified password, which is subject
to length and triviality restrictions.
A maximum length is specified for all user passwords. The minimum password length depends on several parameters set in the authentication
databases.
The system requires a minimum time to elapse before you can change your password. This stops you from reusing an old password too soon.
A password expires after a period of time known as the expiration time. The system warns you when the expiration time is drawing near.
A password dies after a period of time known as the password lifetime. After the lifetime passes, your account is locked until the adminis-
trator reenables it. After unlocking, you must change your password again before you can use your account.
When you successfully type your old password, the system prints the last successful and unsuccessful password change times. Make sure that
these times are accurate; use them to detect attempted password changes by an unauthorized user.
You can change your own password if the administrator has enabled any of the password generation options for your account.
Using the passwd command to reset a user's password does not unlock the user's account if the account is locked for a reason other than an
expired password.
If a password longer than 8 characters was entered under base security and then enhanced security is installed, you must use only the first
8 characters of the original password. This is because base security only used the first 8 characters of the password and the
enhanced/extended password is created from the base password.
See the Security manual for detailed instructions on changing your password.
EXAMPLES
To change your password, enter: passwd
You are prompted for your old password (if it exists). You are then prompted twice for the new password. To change the office num-
ber and building values in your GECOS information, enter: chfn
Your current GECOS values are displayed. Follow the instructions and change your office number. For example, enter: Name [Huan
Kim]: Room Number [3A-41]: 4A-43 Office Phone [3-1234]: Home Phone [555-1234]:
FILES
Contains user information. The list of approved shells. Enhanced security password database for system accounts. Enhanced security pass-
word database for user accounts. Enhanced security's system defaults database.
SEE ALSO
Commands: finger(1), login(1), vipw(8), dxaccounts(8), usermod(8)
Files: matrix.conf(4), prpasswd(4), passwd(4)
Security
passwd(1)