On 6.3.2014 23:06, Alexander Bokovoy wrote:
On Thu, 06 Mar 2014, Jason Woods wrote:
Hi all,

I am quite aware that installing ipa-server-trust-ad and using the
samba as a file server is as unsupported as one can get... but I really
needed a Samba server integrated with IPA (damn Mac OS and Windows). I
don't actually have a Windows environment but this seemed to bootstrap
enough of the requirements to get it working

Bit of a story for those who have time to read and maybe battling
similiar, or just skip to after the log for the fix+patch :)
* ipaNTSecurityIdentifier ended up missing because I didn't use
--setsid and NT hash missing because I did not do a ipa passwd reset
* As a result, experienced user not found or invalid password, and
after debug level 5 I had about 500M of core dumps (sorry don't have
them anymore)
* Ran ipa-adtrust-install again with --setsid and reset some passwords
and things started looking better, could connect, all good, NT hash was
there and ipaNTSecurityIdentifier there (ldapsearch <3)
* Then next problem was when I added "valid users = @groupname" to
share config. No longer could connect even if member of the group!
* Turned out ipNTGroupAttr was missing from some groups - thus had to
register the ldif for the ipa-setsid task
For the record, it is ipa-adtrust-install --add-sids and the task is
called sidgen task.

I noticed the "Could not find uidNumber" - turns out ipa-sam was being
asked to turn SID into ID and was successfully finding it but needed to
work out whether it was a group or a user. To do this, it searches the
objectClass for "ipNTGroupAttr" - if it finds it, it looks for
gidNumber, otherwise it looks for uidNumber. However, the objectClass
added by ipa-setsid is "ipntgroupattr" and ipa-sam was using "strncmp".

I've fixed this with a patch to use strncasecmp. Might not be the best
fix... maybe ipa-sam should be modified to have the attributes lower
case for comparison? But this was simplest patch. Comments/feedback
welcome and maybe I'll have time to do alternative fix if felt better?
You are absolutely on spot here, thanks!

Since we are comparing values of the attribute, we are on our own and
cannot rely on attribute name canonicalization here. This means
strncasecmp() is for the job. I've looked at other options like using
ber_bvcmp() macro but we are really can't guarantee that objectClass
attribute values are in any specific string case because the only matching
rule defined for them is objectIdentifierMatch -- we would have
to turn the value to oid first and then compare which is probably too
much for this specific case.


Versions:
RHEL 6.4 3.0.0-37
Code in master branch appears to show the same issue

References:
freeipa/daemons/ipa-slapi-plugins/ipa-sidgen/ipa_sidgen.h
around line 54-55: lowercase objectClass addition
freeipa/daemons/ipa-sam/ipa_sam.c
around line 688: case sensitive comparison to ipaNTGroupAttrs

Patch for master branch:
diff --git a/daemons/ipa-sam/ipa_sam.c b/daemons/ipa-sam/ipa_sam.c
index 1ca504d..c5e8b39 100644
--- a/daemons/ipa-sam/ipa_sam.c
+++ b/daemons/ipa-sam/ipa_sam.c
@@ -750,7 +750,7 @@ static bool ldapsam_sid_to_id(struct pdb_methods *methods,
    }

    for (c = 0; values[c] != NULL; c++) {
-        if (strncmp(LDAP_OBJ_GROUPMAP, values[c]->bv_val,
+        if (strncasecmp(LDAP_OBJ_GROUPMAP, values[c]->bv_val,
                                   values[c]->bv_len) == 0) {
            break;
        }

Patch for RHEL 6.5 3.0.0-37:
--- a/daemons/ipa-sam/ipa_sam.c    2014-03-06 19:30:15.994792879 +0000
+++ b/daemons/ipa-sam/ipa_sam.c    2014-03-06 19:35:34.966791637 +0000
@@ -685,7 +685,7 @@
    }

    for (c = 0; values[c] != NULL; c++) {
-        if (strncmp(LDAP_OBJ_GROUPMAP, values[c]->bv_val,
+        if (strncasecmp(LDAP_OBJ_GROUPMAP, values[c]->bv_val,
                                   values[c]->bv_len) == 0) {
            break;
        }

This is valid bug. Could you please raise it in bugzilla.redhat.com or,
alternatively, at FreeIPA's trac?

To simply it for you:

The right place is
https://bugzilla.redhat.com/enter_bug.cgi?product=Red%20Hat%20Enterprise%20Linux%206

Version = 6.4
Component = ipa

--
Petr^2 Spacek

_______________________________________________
Freeipa-users mailing list
Freeipa-users@redhat.com
https://www.redhat.com/mailman/listinfo/freeipa-users

Reply via email to