D_PASSWD(5) Standards, Environments, and Macros D_PASSWD(5)

NAME

d_passwd - dial-up password file

SYNOPSIS

/etc/d_passwd

DESCRIPTION

A dial-up password is an additional password required of users who access
the computer through a modem or dial-up port. The correct password must
be entered before the user is granted access to the computer.


d_passwd is an ASCII file which contains a list of executable programs
(typically shells) that require a dial-up password and the associated
encrypted passwords. When a user attempts to log in on any of the ports
listed in the dialups file (see dialups(5)), the login program looks at
the user's login entry stored in the passwd file (see passwd(5)), and
compares the login shell field to the entries in d_passwd. These entries
determine whether the user will be required to supply a dial-up password.


Each entry in d_passwd is a single line of the form:

login-shell:password:


where

login-shell
The name of the login program that will require an
additional dial-up password.


password
An encrypted password. Users accessing the computer
through a dial-up port or modem using login-shell will
be required to enter this password before gaining access
to the computer.


d_passwd should be owned by the root user and the root group. The file
should have read and write permissions for the owner (root) only.


If the user's login program in the passwd file is not found in d_passwd
or if the login shell field in passwd is empty, the user must supply the
default password. The default password is the entry for /usr/bin/sh. If
d_passwd has no entry for /usr/bin/sh, then those users whose login shell
field in passwd is empty or does not match any entry in d_passwd will not
be prompted for a dial-up password.


Dial-up logins are disabled if d_passwd has only the following entry:

/usr/bin/sh:*:

EXAMPLES

Example 1: Sample d_passwd file.

Here is a sample d_passwd file:


/usr/lib/uucp/uucico:q.mJzTnu8icF0:
/usr/bin/csh:6k/7KCFRPNVXg:
/usr/bin/ksh:9df/FDf.4jkRt:
/usr/bin/sh:41FuGVzGcDJlw:

Generating An Encrypted Password

The passwd (see passwd(1)) utility can be used to generate the encrypted
password for each login program. passwd generates encrypted passwords for
users and places the password in the shadow (see shadow(5)) file.
Passwords for the d_passwd file will need to be generated by first adding
a temporary user id using useradd (see useradd(8)), and then using
passwd(1) to generate the desired password in the shadow file. Once the
encrypted version of the password has been created, it can be copied to
the d_passwd file.


For example:

1. Type useradd tempuser and press Return. This creates a user
named tempuser.

2. Type passwd tempuser and press Return. This creates an
encrypted password for tempuser and places it in the shadow
file.

3. Find the entry for tempuser in the shadow file and copy the
encrypted password to the desired entry in the d_passwd file.

4. Type userdel tempuser and press Return to delete tempuser.


These steps must be executed as the root user.

FILES

/etc/d_passwd
dial-up password file


/etc/dialups
list of dial-up ports requiring dial-up passwords


/etc/passwd
password file


/etc/shadow
shadow password file

SEE ALSO

passwd(1), dialups(5), passwd(5), shadow(5), useradd(8)

WARNINGS

When creating a new dial-up password, be sure to remain logged in on at
least one terminal while testing the new password. This ensures that
there is an available terminal from which you can correct any mistakes
that were made when the new password was added.


September 2, 2004 D_PASSWD(5)