Hi,
Just writing here my note about auth_default_realm, pam_krb5 and gssapi.
It seems that 'pam' passdb and 'gssapi' auth_mechanism doesn't honor
'auth_default_realm' setting, at least in several setups I deal with.
Here is a part of the config:
passdb {
args = max_requests=100 cache_key=%u%r dovecot
driver = pam
}
auth_default_realm = REALM.COM
auth_mechanisms = plain login apop gssapi
auth_username_format = %Uu
The problem is that pam_krb5 strips default realm from username (by
default), even if auth_default_realm is specified and even if user logs
in as 'us...@realm.com' (with domain part).
A part of auth.log:
mail auth: pam_krb5(dovecot:auth): user USER1 authenticated as
us...@realm.com
The same for GSSAPI auth, if specified authorization name doesn't
contain domain part.
A part of mail.log:
mail dovecot: imap-login: Login: user=<USER1>, method=GSSAPI,
rip=172.16.0.1, lip=192.168.1.1, mpid=5828, TLS,
session=<bpzvRmDwPACsFwCX>
For several reasons I do need username inside dovecot to contain domain
part. So, I found a solution to this problem - modifying /etc/krb5.conf
this way:
[libdefaults]
default_realm = REALM.COM
[realms]
REALM.COM = {
auth_to_local = RULE:[1:$1@$0]
}
This will add realm part to the local username despite using default
realm.
Maybe it's better to put this example to the wiki?
Tested with ubuntu 12.04 and dovecot 2.2.10, mit kerberos 1.10, amd64.
Taking the opportunity, I'd like to ask, is there a way to make
usernames case insensitive while using GSSAPI. The case:
klist shows:
Principal: us...@realm.com
username in thunderbird 'us...@realm.com'. Dovecot gives me this message
(I use auth_username_format=%Uu for pam_krb5 to be able to login with
lowercase realm):
dovecot: auth:
gssapi(us...@realm.com,172.16.0.1,<IIgwMGbw3ACsFgA4>): User not
authorized to log in as us...@realm.com
As I know kerberos usernames are case insensitive (user part), at least
kinit and windows against AD works that way.
Seems that k5credentials passdb extra field will not help here too. Does
anyone have an idea?
Thanks.
--
Best regards,
Sergey Urushkin
