I wonder if dovecot would consider this feature request. In post login scripting, given USER, IP, LOCAL_IP, and userdb lookup fields, are only available, I want to push additional variables from web mail to dovecot using ID commands yet I looked at the source in imap-login-cmd-id.c and script-login.c it seems to be possible while I'm not an expert in C and IMAP standards and not sure if its something would break the standards.
i think this can do what you need. this little bit of config:
# trusted networks that can use the extended ID data we use for auth now login_trusted_networks = 192.168.0.10 # retain these so we can log client names (when provided) imap_id_retain=yes
makes connections from 192.168.0.10 trusted so that the imap ID fields get passed around during the auth/userdb processes.
if you then use the new lua scripting for the userdb lookup (https://doc.dovecot.org/configuration_manual/authentication/lua_based_authen...), you can get the value of the imap client id via auth_request#client_id
here's a little snippet to get you started:
package.path = package.path .. ";/usr/share/lua/5.1/?.lua" package.cpath = package.cpath .. ";/usr/lib/x86_64-linux-gnu/lua/5.1/?.so" require 'lfs'
function auth_userdb_lookup(req) dovecot.i_info("dovecot-auth.lua: authdb client_id = [" .. req.client_id .. "]") ret = {} ret.client_id = req.client_id // ret.homedir = ...etc... // need the rest of the userdb lookup bits return dovecot.auth.USERDB_RESULT_OK, ret end
you'll want to update that to return everything you need from the userdb lookup, but the data returned by userdb should get pushed to your post_login script. you should see $CLIENT_ID as an env variable with the example code above.
also note: make sure your post login script explicitly calls bash and don't get burned by /bin/sh pointing at dash (as happened to me recently
- otherwise some environment variables might not show up with dash).