The mailing list for listmasters using Sympa

[Adam Bernstein <address@concealed>]

We're excited to start using Sympa's DKIM feature, but having real trouble 
getting it working.  I've set all the necessary parameters in sympa.conf, 
created the DNS record with the public key, etc., and I can get it to sign 
messages.  But the signatures are apparently not valid; sending them to a 
DKIM evaluation autoresponder like address@concealed results in 
a response saying:

This is the overall result of the message verification:
  fail (message has been altered)

I've tested replicating my DKIM setup (keys and DNS record) on another 
server and sending signed messages directly to the autoresponder, and then 
it all works fine.  So something on our Sympa system is somehow modifying 
the message, *after* it's sent to DKIM for signing, which I don't 
understand because the DKIM signing is literally the line before the SMTP 
handoff in bulk.pl.

I've also tried reducing the number of headers that are signed, and editing 
tools.pm to relax the whitespace sensitivity (literally, changing the 
"relaxed" setting to "relaxed/relaxed", so it applies to both headers and 
body).  But still no success.  I get signed messages, but the signature is 
not valid.

Here's the sympa.conf setup:

dkim_feature    on
dkim_add_signature_to   robot
dkim_header_list        from
dkim_selector           npogroups
dkim_signer_domain      npogroups.org
dkim_private_key_path   /usr/local/etc/certs/dkim-private.key

And my certs look like:

npogroups# ls -l /usr/local/etc/certs/
-rw-------  1 sympa  sympa   887 Dec  9 17:15 dkim-private.key
-rw-r--r--  1 sympa  sympa   272 Dec  9 17:16 dkim-public.key

And my public key in the npogroups.org DNS:
npogroups._domainkey    IN      TXT     "k=rsa; 
p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCgmyvwYDwrhkxkbidHwrJfGj24I76THWMGt+Z7jTN7vaH4IeeJw6hv
p2Sp3q5/6YbGvlkbzutrMfhOxU6lD5CLyv2BgOr6C6WQCLKjWCPCieNF4OPs2lrc8jd+zChPxNQSVd5zWOTyTWXQDH8d9D1MoyoO2Kn4oV+MO3FmTv9oTwIDAQAB; 
t=y;"

Thanks, Sympa folks or anyone else, for any help at all!

     adam