[imp] PGP support in IMP and other email clients

[Michael M Slusarz]

Quoting "admin@canc.rpa.cs.nsw.gov.au" <admin@canc.rpa.cs.nsw.gov.au>:

| I've been using the latest cvs code for the purposes of getting PGP
| working.
| I've sent a friend an encrypted email twice and then sent him a 3rd plain
| text
| email asking if he got the previous 2 emails. He said he did, but, they
| came up
| as empty PGP attachments. I thought it strange because the encrypted
| emails I
| sent to myself in IMP I could decrypt and read fine. I tried to read the
| same
| emails in Mozilla Messenger and the messages came up as blank. It wasn't
| until I
| looked at the "message source" that I saw the PGP encrypted message. My
| guess is
| that it's related to the "application/pgp" MIME type not being understood
| by
| other email clients.

Not sure what you mean by this.  We never send the 
antiquated "application/pgp" MIME content-type in anything we do.  We only 
send "application/pgp-encrypted", "application/pgp-signed", 
and "application/pgp-keys".  This conforms to the mandates in RFC 2015/3156.

Additionally, our MIME message formatting conforms to the standards found 
in RFC 2015/3156.  For both signing and encrypting, you MUST encapsulate 
both the body and signature/data in a "multipart" MIME part.

I'm not sure why Mozilla won't view the messages - but I have tested PGP 
messages sent from IMP with both mutt and pine + PGP extensions and they 
handle the messages just fine.  I really rely on mutt since Michael Elkins, 
the original author of mutt, is the main author of the RFCs.

| Normally, my friend sends his PGP emails as plain text encrypted from his
| clipboard, no fancy MIME encoding. The whole MIME types thing is a bit
| beyond
| me, but, I wonder why IMP needs to MIME encode the PGP data when it's
| already in
| text format. Perhaps a checkbox could be added to compose.php to send
| emails
| without any MIME-encoding with PGP.

This is NOT an option inder RFC 2015/3156.  However, we parse for this 
format in incoming messages just to catch older mailers who may still do 
this.

You are correct in stating that we MIME encapsulate the PGP stuff because 
it enables the MUA to better/more easily recognize and handle these 
messages than if it appears in straight text (the latter option requires 
_every_ message to be parsed for PGP information, a time-consuming 
operation).

michael

______________________________________________
Michael Slusarz [slusarz@bigworm.colorado.edu]
The University of Colorado at Boulder