Modifying ISC V3.3 R2.2 signon messages

[Dave McLane]

Sorry about my mistakenly starting a new subject in the middle of
the SECURITY BUG thread.

Following is a summary of what I've learned about how the ISC
signon messages get generated.

------------------------------

jgd at Dixie.Com (John G. DeArmond) writes:

> bill at unixland.uucp (Bill Heiser) writes:
>
> >This is a good question (for those of us who don't know) -- how does
> >one edit binaries in Unix?  Is there a utility like Norton out there
> >(yes, I know Norton is available for ISC, but I'm running Esix).

I am running plain MS-DOS Norton utilties under VP/ix uner ISC V3.2
and the ones I've tried work except for DS (directory sort). Likewise
MS-DOS SYMDEB.EXE works as well....

> Well, I use fm, what the author calls file modify.  We refer to it as
> F...... Magic :-)  The source is included in this posting.

Thanks for including it, I'll give it a whirl.

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it1 at ra.MsState.Edu (Tim Tsai) writes:

> Check out fm, a curses based binary editor for Unix.  It's available
> in comp.sources.misc, volume12.

We don't get those on Aegis but I know where I can.... thanks for
the reference.

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shwake at raysnec.UUCP (Ray Shwake) writes:

> This assault of the copyright credit lines is not limited to ISC.
> ...
> UCB, for example, all I encountered was a clean login prompt. I suspect
> these references are all coming out of /bin/login.

> On a related issue, both ISC and SCO UNIX *prefix* the login prompt
> with a node name reference and a couple of new lines. *This* one, I believe,
> comes out of getty.

So I found out.... see belows

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cpcahil at virtech.uucp (Conor P. Cahill) writes:

> yes, they come out of getty.  Most of it comes out of the /etc/issue file
> that getty reads, so changing that file will get rid of most of the pre-login
> prompt stuff.

Yes, part of it, see below.

------------------------------

Based upon what I've learned from your replies, I puttered about
and here is what I know about where the header is coming from:

1. /etc/issue     | Welcome to the INTERACTIVE Systems Corporation
                           INTERNACTIVE UNIX Operating System

2. /etc/getty     | System name: Aegis

3. /etc/gettydefs | Login:

4. /bin/login     | Password:

5. /bin/login     | UNIX System V/386 Release 3.2
                  | aegis
                  | Copyright (C) 1984, 1986, 1987, 1988 AT&T
                  | Copyright (C) 1987, 1988 Microsoft Corp.
                  | All Rights Reserved.
                  | Login last used Mon Mar 25 18:47:57 1991

6. /etc/profile   | /                : Disk space....
   /etc/profile   | /usr             : Disk space....
   /etc/profile   | /user2           : Disk space....
   /etc/profile   |
   /etc/profile   | Total Disk Space....

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To change, you can do the following:

1. Edit /etc/issue to change the opening lines

2. Binary edit /etc/getty. But there are limits to what you can do.  
   I used "strings -o getty" to locate the address of "System name" 
   and found two strings one after the other: "System name:<0>%s<0>".
   I used SYMDEB.EXE under VP/ix to make the modificationds (binary 0
   in the first byte of each string to kill it) and wrote the
   changes to getty.aegis and then used that for the dialup lines
   in /etc/conf/init.d/asy. But I didn't get the results I thought
   I would get! Instead of no "System name: aegis" I got "aegis"
   and then it was waiting for me to login but with no prompt.

   So while you can kill "System name:" by putting a <0> in the
   first byte, the actual name of the system is coming from someplace
   else in the code and the "%s" is used for the login promt coming
   out of the /etc/gettydefs file.

   Oh well, I guess I don't mind the "System name: Aegis" so much....

3. Edit whatever entry /etc/gettydefs is relevant, depending
   on the /etc/inittab.

   I have edited mine to show which entry in the cycle is being
   used for testing how my modem setup works (19200-Login,
   9600-Login ... 300-Login)

4-5. Binary edit /etc/login. I used "strings -o login" to locate the
   address and then used SYMDEB.EXE under VP/ix to make the
   modification I wanted. I left Password alone and stuck binary 0
   in the as the first byte in the copyright message to kill it.

6. Edit /etc/profile as you wish

------------------------------

My resulting Signon was:

  Aegis Society UNIX Operating System

  System name: Aegis

  9600-Login:
  Password:

  Login last used Mon Feb 17 18:47:57 1991
  Total Disk Space....

I think this simplified and beautified sigon will avoid my having
to explain a lot of of irrelevant details to the people who are 
going to be using Aegis.

Thanks for your help....

--Dave