[Freeipa-devel] [PATCH] 1059 single CRL generator

[Martin Kosek]

On 10/04/2012 06:17 PM, Rob Crittenden wrote:
> This changes the way IPA generates CRLs for new installs only.
> 
> The first master installed is configured as the CRL generator. An entry is
> added to cn=masters that designates it.
> 
> When a replica is installed it queries this entry so it knows where to forward
> CRL requests. CRL files are not available on cloned CAs (so /ipa/crl will
> return not found). It is possible to get a CRL directly from the clone CA via
> http://<hostname>:9180/ca/ee/ca/getCRL?op=getCRL&crlIssuingPoint=MasterCRL
> 
> rob

I tested new IPA server + replica with your patch and the CRL was now generated
only on the CRL master. I also tried OCSP (though this may not be relevant) and
it worked for me too.

1) I do not understand the following block in set_crl_master(self, suffix):

+        try:
+            self.admin_conn.addEntry(entry)
+        except ldap.ALREADY_EXISTS, e:
+            root_logger.debug("failed to set CA as CRL generator")
+            raise e

- when we hit ldap.ALREADY_EXISTS, we are actually OK because cn=CRL is set, right?
- AFAIK, addEntry should  return our errors, i.e. errors.DuplicateEntry
- s/raise e/raise/

I think you may have wanted to rather catch for more general LDAP error and
then report a real error and not just a debug note.

2) In get_crl_master:

+        except Exception, e:
+            root_logger.debug("Could not connect to the Directory Server on
%s: %s" % (master_host, str(e)))
+            raise e

s/raise e/raise/

+        except errors.NotFound, e:
+            root_logger.debug("failed to find CA CRL generator")
+            self.crl_master = None

- e is actually not used, "except errors.NotFound" would be enough

3) Majorish issue I hit with the actual CRL publishing on our server (F17). I
always get 403 Forbidden error when trying to download CRL from the CRL master:

# wget --ca-certificate /etc/ipa/ca.crt https://`hostname`/ipa/crl/MasterCRL.bin
--2012-10-05 03:32:58--
https://vm-120.idm.lab.bos.redhat.com/ipa/crl/MasterCRL.bin
Resolving vm-120.idm.lab.bos.redhat.com... 10.16.78.120
Connecting to vm-120.idm.lab.bos.redhat.com|10.16.78.120|:443... connected.
HTTP request sent, awaiting response... 403 Forbidden
2012-10-05 03:32:58 ERROR 403: Forbidden.

I tracked the problem down to too strict permission on /var/lib/pki-ca
directory which is being published by httpd which does not have access to it:

# ll /var/lib/pki-ca

drwxrwx---. 11 pkiuser pkiuser 4096 Oct  5 03:00 pki-ca

When I fixed the permission:
# chmod o+x /var/lib/pki-ca/

I was able to get pass the Forbidden error and actually retrieved the CRL.
Adding Ade on CC list to follow on this permission issue.


I was thinking about usability of this new approach, we may want to make user
life easier in a perspective of CRL master managing. I have following
enhancements in mind:

- mark CRL master in ipa-replica-manage list, or ipa-csreplica-manage list:

# ipa-csreplica-manage list
Directory Manager password:

vm-065.idm.lab.bos.redhat.com: master [CRL]
vm-120.idm.lab.bos.redhat.com: master

- when removing master with CRL by "ipa-replica-manage del" we should warn user
and inform him what he should do next to amend the situation. I am thinking
about 2 new commands for ipa-csreplica-manage:

* ipa-csreplica-manage crl-promote
  - promote current master as the new CRL master, enable CRL generation in
CS.cfg, mark master as the new CRL master in cn=masters
* ipa-csreplica-manage crl-update
  - update CS.cfg of current CA replica and point master.ca.agent.* to current
CRL master

I can work on those enhancements if we agree on them.

Martin