Dialup Modem Password

[Mohd Mohtar]

Hi,

I am very new to system administration
to Unix. Recently, I've just add a
modem to the server (10.20) using SAM. I am able to login to the server remotely as a normal session via a terminal (I use HyterTerm).
With regards to this, I wanted to know if there is a way to add a security feature which will prompt "Dialup password" apart from the normal login prompt whenever user login to the server remotely. I notice however,
that under the Help menu in SAM, there are
some options pertaining to security
access in the "Terminals and Modems
Subarea Browsable Help".
Unfortunately,my server is not Trusted and unable to use these options.
Appreciate any assistance to setup the dialup modem password in an Untrusted system.

Thanks a lot ..

[Uday_S_Ankolekar]

Hi,

Modem security features can be enabled within modem settings. It's one of the 'AT' command. Refer your Modem manual.
Two types security features can be configured
1. Dial back feaure in which server modem dails back to the source.
2. Storing password inside the modem

I did this long long time. But I;m sure if you have manual then it's easy one.

Goodluck,
-USA..

[Mohd Mohtar]

Hi Uday,

I have browse thru the modem manual and found one command "#Sy" to enter the remote configuration setup password.
Is this the correct command? If it is, how do I actually configure it in Unix.
Really appreciate your assistance in this.

Thanks

[Alexander M. Ermes]

Hi there.
Did you create the device files for the modem ( ttyxynn and cuaxynn and culxynn ) ?
If not, create them from SAM or search the ITRC for the word 'modem' ( you will find some docs there ).
If you have these files, enter 'cu -l /dev/culxynn direct'.
If you get an ok, you can setup the modem.
Rgds
Alexander M. Ermes

[Uday_S_Ankolekar]

Hello,

I'm not sure about that, because each modem would have different kind of settings. What modem you use..?

-USA..

[Fred Martin_1]

I set up ours by installing these two files:

/etc/dialups
/etc/d_passwd

Have a look at 'man dialups' for an explanation of both.

The first just defines the devices that you want to have use the dialup password. It'll be the device file associated with the modem. In my case the file contains these two lines (two modems):

# cat /etc/dialups
/dev/ttyd2a1
/dev/ttyd2a2

The second file is a password file, containing the dialup password in encrypted form, just like /etc/passwd - but you need one entry for every shell your users will be using. Mine looks like this:

# cat /etc/d_passwd
/usr/bin/csh:xxxxxxxxxxxxx:0:0:::
/usr/bin/ksh:xxxxxxxxxxxxx:0:0:::

The second field will actually have the password, encrypted, not xxx's as I have shown.

If I remember correctly you use the passwd command to set that up, but use the -F option to specify the /etc/d_passwd file. See 'man passwd'

Fred

[Fred Martin_1]

I should have mentioned that the solution I suggested is a unix solution, and requires no setup on the modem itself.

[Mohd Mohtar]

Hi Guys,

Here are my replies to each one of u.

Uday,
I am using MultiTech ZDX Modem. Model MT1932ZDX.

Alex,
I'm not too sure on creating the files.

Fred,
I've created the files /etc/dialups and /etc/d_passwd.
In my /etc/dialups, it contain /dev/ttyd0p7.
In my /etc/d_passwd, it contain /usr/bin/sh::0:0:::
Then, I issue the cmd "passwd -F /etc/d_passwd /usr/bin/sh". It gives me "Invalid login name".
I modify the /etc/d_passwd to replace the /usr/bin/sh with a userid and reissue the cmd passwd -F /etc/d_passwd userid. This time, it prompt me for "New Password:".
I then try to login to the server via a terminal and it will prompt for login and passwd. After responding to these, it prompt me another login "Dialup password". This time, I issue the password which I had changed thru the passwd -F cmd but it doesn't work.
What actually went wrong ?

Sorry guys, for these lengthy message.

Thanks for the response. Hope to hear from u guys soon.

[Fred Martin_1]

Here's the procedure I've been using, as root:

# passwd -f /etc/d_passwd /bin/sh
New password:
Re-enter new password:
# passwd -f /etc/d_passwd /bin/csh
New password:
Re-enter new password:

Works for me.

[Fred Martin_1]

I just noticed you're using /usr/bin/sh and not /bin/sh.

I don't recall why but I also tried that, had to use /bin/sh - maybe someone else here knows the reason. Both of those files have the same inode on my system so I assume they are really the same file.

In any case my users have /usr/bin/sh as the login shell (/etc/passwd) but the dialup modem has /usr/sh.

Try that.

[Fred Martin_1]

This link was something I just found:

http://us-support.external.hp.com/cki/bin/doc.pl/sid=af41df8014c09902ab/screen=ckiDisplayDocument?docId=200000054497757

[Mohd Mohtar]

Hi Fred,

Sorry for the late reply. I've changed the /usr/bin/sh to /bin/sh in the /etc/d_passwd file. Issuing of passwd -F /etc/d_passwd /bin/sh was a success.
However, I still can't login to the server via a terminal. After typing the password at the "Dialup Password" prompt, error 'Invalid user' was given. What can possibly went wrong this time. Please help.