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System Manager's Notes: poppassd v2.1beta

*** Written by Joel Snyder under contract to Schlumberger
*** Donated to the Public Domain by Schlumberger (David Sims  'dpsims@slb.com')
*** Please give credit on any modifications or re-distributions
*** *Not* for re-sale

Installation Instructions
=========================

0- READ THROUGH THE SOURCE TO MAKE SURE THAT THIS DOES WHAT YOU 
   WANT IT TO DO ! ! !

1- Compile and link it properly.  To do that, create a .com file which
   contains the following:

$ cc poppassd		(if you have DEC C, cc/vaxc)
$ link poppassd,sys$input:/opt/notrace
  MULTINET:MULTINET_SOCKET_LIBRARY/SHARE
  SYS$SHARE:VAXCRTL/SHARE

2- Put it somewhere.  I suggest you put this in your
   MULTINET_COMMON_ROOT:[MULTINET] directories, unless you have some
   place else where you keep images like this.  To do that:

$ copy poppassd.exe multinet_common_root:[multinet]

3- make Multinet know about it.  To do that (assuming you stuck the
   file in multinet:poppassd.exe):

$ multinet config/server

SERVER-CONFIG>add poppassd
[Adding new configuration entry for service "poppassd"]
Protocol: [TCP]
TCP Port number: 106
Program to run: MULTINET:poppassd.EXE
[Added service poppassd to configuration]
[Selected service is now poppassd]
SERVER-CONFIG>show/full
Service "poppassd":
         TCP socket (AF_INET,SOCK_STREAM), Port 106
         Socket Options = SO_KEEPALIVE
         INIT() = TCP_Init
         LISTEN() = TCP_Listen
         CONNECTED() = TCP_Connected
         SERVICE() = Run_Program
         Program = "MULTINET:poppassd.EXE"

SERVER-CONFIG>restart

Things you can customize
========================

POP Passwd's behavior can be changed using a variety of system-wide
logical names.  The poppassd_LOG_FILE logical name must be defined.
It is currently defined as 'poppassd.log'. Or you must define
poppassd_DONT_LOG so that poppassd won't write log files (not recommended).

poppassd_LOG_FILE	This should be defined to point to the location
	where poppassd will log everything that happens.  By default,
	(assuming that you have followed the other instructions and
	recommendations) this code will write the log as: 

	MULTINET_COMMON_ROOT:[MULTINET]poppassd.log.

poppassd_DONT_LOG	Normally, poppassd logs everything, both errors
	and successes, to a log file.  This is usually a pretty good idea.
	However, if you do not want poppassd to leave any traces of
	what it has done (including attempted breakins!), then define this
	logical name and it will do no logging.

poppassd_DEBUG		You normally would have no reason to define this.
	However, if you do, then poppassd will babble all sorts of
	interesting debugging information.  Defining this logical does NOT
	introduce any security problems; all it does is increase the
	amount of logging to the screen which poppassd will do.  If you
	define this logical name, then it is likely that Eudora will not
	be able to talk to poppassd.

poppassd_ANAL_MODE	Normally, poppassd is pretty chatty with users
	about why it was unable to change their password.  It will tell
	them if a particular username is valid, if they have given an
	incorrect password, or if there is a syntax error.  Some sites
	may not like the idea of this much information being given out.
	If you define poppassd_ANAL_MODE, then poppassd is very
	tight-lipped about the error messages which it gives to the
	client.  This does not affect the log files, though.

poppassd_IGNORE_LENGTH	Normally, poppassd pays attention to the minimum
	length of password field in each user's UAF entry.  If, for some
	very strange reason, you do NOT want poppassd to do this, then
	define this logical name.  This is strongly discouraged!

poppassd_IGNORE_CAPTIVE	Normally, poppassd will not allow users
	who have the CAPTIVE flag in their UAF entry to change their
	password.  If you would like to allow these users to change
	their passwords, then define this logical name.

poppassd_IGNORE_DISUSER	Normally, poppassd will not allow users
	who have the DISUSER flag in their UAF entry to change their
	password.  If you would like to allow these users to change
	their passwords, then define this logical name.  This is strongly
	discouraged!

poppassd_IGNORE_GENPWD		Normally, poppassd will not allow users
	who have the GENPWD flag in their UAF entry to change their
	password.  If you would like to allow these users to change
	their passwords, then define this logical name.  This is
	strongly discouraged!

poppassd_IGNORE_LOCKPWD	Normally, poppassd will not allow users
	who have the LOCKPWD flag in their UAF entry to change their
	password.  If you would like to allow these users to change
	their passwords, then define this logical name.  This is
	strongly discouraged!

poppassd_IGNORE_RESTRICTED	Normally, poppassd will not allow users
	who have the RESTRICTED flag in their UAF entry to change their
	password.  If you would like to allow these users to change
	their passwords, then define this logical name.  

Internals of the protocol
=========================

 Steve Dorner's description of the simple protocol:

 The server's responses should be like an FTP server's responses; 
 1xx for in progress, 2xx for success, 3xx for more information
 needed, 4xx for temporary failure, and 5xx for permanent failure.  
 Putting it all together, here's a sample conversation:

   S: 200 hello\r\n
   E: user yourloginname\r\n
   S: 300 please send your password now\r\n
   E: pass yourcurrentpassword\r\n
   S: 200 My, that was tasty\r\n
   E: newpass yournewpassword\r\n
   S: 200 Happy to oblige\r\n
   E: quit\r\n
   S: 200 Bye-bye\r\n
   S: <closes connection>
   E: <closes connection>