Subject: Re: popclient and a socket -P (password) file.

From: Lars Wirzenius <[email-masked]>
Date: Mon, 08 Jul 1996 07:39:13 +0300

[ NB: I read the list.  Don't CC replies to me.  I pay for my PPP.  Thanks ]

Rob Browning:
> And the pixie approach does have the advantage that my password's
> never left lying about when I log out.

Doesn't POP still require transmitting the password in clear over the
net?  I've been told it does (and have a hack that uses ssh instead).
A public spirited person might want to add an extension to the protocol
that doesn't transmit the password (server sends random bit string,
client appends password and computes MD5, server does the same and compares).
It might be possible to do this so that the server accepts both POP and
the extension (with an option of not accepting one of them).

The modifications should be relatively trivial, if the protocol is 
sensible.

---

From: Rob Browning <[email-masked]>
Date: 06 Jul 1996 14:59:39 -0500

Would it be a bad idea to add support in popclient for reading it's
password from a socket when -P is specified?  I was thinking about
using it with a "pixie" program like the one that was part of
auto-pgp.  I modified the pixie script to do the right thing, but
popclient refuses to read anything that's not a regular file.

Is there some better way of handling this?  I know about the .netrc
support, but I thought that that would be much less secure than the
socket approach.  Not that I know that for sure, but I was assuming
that there was some reason that auto-pgp was set up the way it was.
And the pixie approach does have the advantage that my password's
never left lying about when I log out.

Thanks
--
Rob

---

From: Lars Wirzenius <[email-masked]>
Date: Tue, 09 Jul 1996 11:50:45 +0300

> The modifications should be relatively trivial, if the protocol is 

I grabbed the RFC for POP3 and it would indeed be pretty trivial to do it.
I'm not sure it would be really worth it (the letters would still be
transmitted in cleartext), and anyway, I'm not really in need of it
myself.  If anyone wants it badly enough, however, I might have a stab
at it one day.  I won't bother, unless someone tells me they're willing
to install it.  (I would only make the change in qpopper and popclient;
other clients would need to be modified by others.)

---

From: Michael Shields <[email-masked]>
Date: Tue, 9 Jul 1996 14:59:12 +0000

>the extension (with an option of not accepting one of them).

This is already standardized -- it's the APOP command.

--
Shields, CrossLink.

---

From: Ian Jackson <[email-masked]>
Date: Wed, 10 Jul 96 01:11 BST

> popclient refuses to read anything that's not a regular file.

You can't just open a socket for reading - you have to connect() to
it.

> never left lying about when I log out.

Perhaps an option to popclient to read the password from stdin rather
than /dev/tty ?  Then you could do what pgp-auto does for pgp (connect
up the socket and invoke pgp).

Ian.

---

From: Mark Eichin <[email-masked]>
Date: 10 Jul 1996 14:33:41 -0400

see also the ietf draft "SASL", basically an abstract version of the
IMAP security interface -- this would probably be the "right" way to
add security to pop. (There is already a kerberos v4 pop3
implementation, but calling it a design would be a bit extreme.)

---

From: Rob Browning <[email-masked]>
Date: 16 Jul 1996 09:21:39 -0500

> You can't just open a socket for reading - you have to connect() to

Right, I knew that, but I was just explaining the problem...

> up the socket and invoke pgp).

That would certainly solve the problem.

--
Rob