Trouble connecting with IMAP (Windows Emacs with Cygwin SSL/TLS tools)

Trouble connecting with IMAP (Windows Emacs with Cygwin SSL/TLS tools)

[Steven E. Harris]

I posted a message¹ with the same subject line to the gnu.emacs.gnus
newsgroup, but traffic has been slow there lately. Perhaps the crowd
here will be more capable to suggest a solution.

I'll repeat the message body of the first message here:


I have a recent CVS snapshot of Gnus setup with the Cygwin XEmacs build
and the rest of the Cygwin tools (openssl, starttls) working just
fine. I can connect to various IMAP servers with encrypted connections.

Recently I set up a Windows build of Emacs (GNU Emacs 22.2.1) and I'm
trying to get Gnus to work with it similarly. Gnus is able to connect
(unencrypted) to NNTP servers, but all of my attempts to connect to IMAP
servers fail. I suspect it's a coding system problem with using Cygwin
programs to handle the encrypted connections.

Here's the *imap-log* buffer resulting from an attempted connection to
my IMAP server:

,----[ *imap-log* ]
| depth=0 /O=mail.panix.com/OU=Go to https://www.thawte.com/repository/index.html/OU=Thawte SSL123 certificate/OU=Domain Validated/CN=mail.panix.com
| verify error:num=20:unable to get local issuer certificate
| verify return:1
| depth=0 /O=mail.panix.com/OU=Go to https://www.thawte.com/repository/index.html/OU=Thawte SSL123 certificate/OU=Domain Validated/CN=mail.panix.com
| verify error:num=27:certificate not trusted
| verify return:1
| depth=0 /O=mail.panix.com/OU=Go to https://www.thawte.com/repository/index.html/OU=Thawte SSL123 certificate/OU=Domain Validated/CN=mail.panix.com
| verify error:num=21:unable to verify the first certificate
| verify return:1
| * OK [CAPABILITY IMAP4rev1 SASL-IR SORT THREAD=REFERENCES MULTIAPPEND UNSELECT LITERAL+ IDLE CHILDREN NAMESPACE LOGIN-REFERRALS QUOTA AUTH=PLAIN AUTH=LOGIN] Dovecot ready.^M
| 55 LOGOUT^M
| * BYE Logging out^M
| 55 OK Logout completed.^M
| read:errno=0
| 56 LOGIN "seh" "mypass"^M
`----

Some things look strange here. Not the "^M" terminators on the lines
sent and received from the server. Also note how one side logs out
/before/ it logs in.

Here's part of the *Messages* buffer during the login attempt:

,----[ *Messages* ]
| Checking new news...
| Opening nnimap server on panix...
| imap: Connecting to mail.panix.com...
| imap: Opening SSL connection with `openssl s_client -CApath /usr/ssl/certs -quiet -ssl3 -connect %s:%p'...done
| Waiting for response from mail.panix.com...done
| Parsing authinfo file `~/.authinfo'.
| imap: Plaintext authentication...
| Unable to open server due to: Buffer  *nnimap* panix has no process
| Unable to open nnimap:panix, go offline? (y or n) 
| Opening nnimap server on panix...failed
| Checking new news...done
`----

I see that there are the two variables `imap-coding-system-for-write'
and `imap-coding-system-for-read', which are set to `binary' by
default. Might resetting those be related to solving this problem?

Any advice would be appreciated.


Footnotes: 
¹ <83hc9lghtb.fsf@torus.sehlabs.com>
  http://groups.google.com/group/gnu.emacs.gnus/msg/a90169bb2ec0d44b
  http://groups.google.com/group/gnu.emacs.gnus/browse_frm/thread/9d36d318c574966b

-- 
Steven E. Harris