[Freeipa-devel] [PATCH] 210 Allow SAN in IPA certificate profile

[Martin Kosek]

On 06/18/2014 02:09 PM, Jan Cholasta wrote:
...
>>>> 3) I am thinking why do we need to introduce all the ASN parsing? I am talking
>>>> about _decode_krb5principalname and others. If we do not use the result
>>>> anywhere, why should we include this part at all?
>>>
>>> To work around shortcomings of NSS/python-nss. In particular,
>>> _decode_krb5principalname is used to decode KRB5PrincipalName SANs to a string.
>>> This is necessary because certmonger puts such SANs in certificate requests it
>>> generates.
>>
>> I know, but we do not use the values besides DNS SAN type, right? I was just
>> afraid that a decode error in a decoding of an unused SAN type would cause the
>> entire CSR processing to crash.
> 
> If we do not allow principal name SANs, requests from certmonger will fail. If
> we allow them, but ignore them, you could request a certificate for an
> arbitrary unrelated principal. Thus, the only thing we can do is allow them and
> validate them, which is what the patch does and why decoding KRB5PrincipalName
> is necessary.

True, we need to make sure the principal type SANs match. ack on the intent.

>>>> 4) I get crash in the certmonger request:
>>>>
>>>> ipa-getcert request -d /etc/pki/nssdb/ -n test-san-1 -I test-san-1 -g 2048 -r
>>>> -N "cn=`hostname`" -K host/`hostname` -D test1.example.com -D
>>>> test2.example.com
>>>> -E mkosek at redhat.com
>>>>
>>>> # ipa-getcert list -i test-san-1
>>>> Number of certificates and requests being tracked: 8.
>>>> Request ID 'test-san-1':
>>>>      status: CA_UNREACHABLE
>>>>      ca-error: Server failed request, will retry: -504 (HTTP response code is
>>>> 500,
>>>> not 200).
>>>>      stuck: yes
>>>>
>>>>
>>>> HTTPD traceback
>>>> [Mon Jun 16 13:06:14.528642 2014] [:error] [pid 12941] [remote
...
>>>> PyAsn1Error: TagSet(Tag(tagClass=128, tagFormat=0, tagId=2)) not in asn1Spec:
>>>> _GeneralName()
>>>
>>> What version of certmonger are you using?
>>
>> Latest Fedora 20, i.e. should be certmonger-0.71.2-1.fc20 (do not have access
>> to my VM atm). Is this a bug in certmonger?
> 
> No, it's bug in my code. Fixed.

Works.

> Also added patch 301 which fixes a bug in ldap2.get_effective_rights I was
> hitting with patch 234.
> 
> Updated patches attached.
> 

Thanks. Functionally, the patch looks ok to me, we are close to final ack. Just
couple more minor changes need to happen:

1) We decided to drop ipaVirtualOperation concept in the end and allow people
reading this list. This implies following changes:

234 - drop ipaVirtualOperation from cn=request certificate with
subjectaltname,cn=virtual operations,cn=etc,$SUFFIX
300 - drop the entire patch (sorry)

2) I would like to have more confidence that no unauthorized SAN extension gets
in. I know we have the

+        for name_type, name in subjectaltname:
+            if name_type not in (pkcs10.SAN_DNSNAME,

loop, but I would also like to add "else" path to the SAN type validation loop,
in case somebody just expands the part above, but forgot to also add
validation. I want us to be explicit in this case:

+        for name_type, name in subjectaltname:
+            if name_type == pkcs10.SAN_DNSNAME:
...
+            elif name_type in (pkcs10.SAN_OTHERNAME_KRB5PRINCIPALNAME,
+                               pkcs10.SAN_OTHERNAME_UPN):
...
>            else:
>                 raise errors.ACIError(info=_(
>                        "Unauthorized subject alt name '%s'.") % name)


When this is fixed, we should be done.

Thanks,
Martin