Hey Marek,
I need to follow up on this.
I have made a first draft of the implementation. However, it seems that certificates are
much longer than currently supported by the value field in the user_attribute table.
Increasing filed length has been discussed in
https://issues.jboss.org/browse/KEYCLOAK-2382, but I could not really figure out what the
current status is? It does not seem to be implemented. Do you see a chance for increasing
the field length?
Regards
Sven-Torben
-----Ursprüngliche Nachricht-----
Von: Marek Posolda <mposolda(a)redhat.com>
Gesendet: Montag, 25. März 2019 12:25
An: Sven-Torben Janus <sven-torben.janus(a)conciso.de>; keycloak-dev(a)lists.jboss.org
Betreff: Re: AW: AW: [keycloak-dev] X.509 User Identity Extractor - multiple values
On 22/03/2019 11:43, Sven-Torben Janus wrote:
Hey Marek,
as far as I know, RFC 2587 specifies the usercertificate attribute for exactly that
purpose. Active Directory also knows something similar (see
https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-ada3/f9e9...).
Thanks for pointing this. It seems it may be useful to have OOTB
UserIdentityExtractor, which will work with the MSAD "userCertificate"
attribute. So if you have a chance to contribute this, I think it will be fine.
IMHO matching the certificate against a custom LDAP attribute should
also be ok. At least that is what the custom attribute mapper for the existing "user
mapping method" is doing anyways for all the other user identity sources (like
subjectDN, common name etc.), right?
Maybe it is thin line, but in general, I see that having OOTB extractors, which are able
to pair users based on subjectDN or commonName looks natural and will probably work for
most of the people.
Having something very specific like "issuer;serialNumber" is IMO not generally
useful, so I would rather avoid to have the UserIdentityExtractor in Keycloak OOTB.
Marek
Regards
Sven-Torben
-----Ursprüngliche Nachricht-----
Von: Marek Posolda <mposolda(a)redhat.com>
Gesendet: Freitag, 22. März 2019 10:20
An: Sven-Torben Janus <sven-torben.janus(a)conciso.de>;
keycloak-dev(a)lists.jboss.org
Betreff: Re: AW: [keycloak-dev] X.509 User Identity Extractor -
multiple values
Thanks for the clarification
TBH It seems to me that probably even (b) won't be very generally useful. Unless for
example some LDAP servers store the certificate PEM in some standard LDAP attribute of the
user? But if it's customization of LDAP schema specific to your environment to be able
to save the certificate PEM in the LDAP attribute, then my vote is to not add it.
Marek
On 21/03/2019 17:18, Sven-Torben Janus wrote:
> Hi Marek,
>
> I agree to your thoughts on solution a). That's basically why I wanted to discuss
it here, before starting an implementation.
> Regarding, solution b), yes that is what I thought about (with or without the
initial/final lines).
>
> Sven-Torben
>
> -----Ursprüngliche Nachricht-----
> Von: Marek Posolda <mposolda(a)redhat.com>
> Gesendet: Donnerstag, 21. März 2019 10:54
> An: Sven-Torben Janus <sven-torben.janus(a)conciso.de>;
> keycloak-dev(a)lists.jboss.org
> Betreff: Re: [keycloak-dev] X.509 User Identity Extractor - multiple
> values
>
> Hi,
>
> The solution (a) looks quite specific to the environment and I don't think that
it will be useful to have this as a generic feature in Keycloak.. Solution (b) looks like
bit more generally useful, but still not 100% sure about adding it to Keycloak... For the
solution (b), are you talking about the PEM String representation of the X509 certificate,
which just excludes the initial and final lines (Those with "BEGIN CERTIFICATE"
and "END CERTIFICATE" )?
>
> Marek
>
> On 21/03/2019 07:48, Sven-Torben Janus wrote:
>> Hey all!
>>
>> I am currently facing a situation with a customer who wants to implement mutual
SSL / client cert authentication. As I understand from the UserIdentityExtractor[1]
implementations, currently only returning a single value is allowed, because the
UserIdentityToModelMapper[2] calls toString on the actual userIdentity object.
>>
>> Now my customer uses the serial number from the certificate to identify users.
However, this is only unique in combination with the issuer of the certificate, since my
customer supports multiple CAs. The combination of both exists in their LDAP as a single
attribute where both parts are separated by a special separator character.
>> In addition to that, the whole certificate of the user is also available in
another LDAP attribute.
>>
>> I currently see the following options to implement a solution for this:
>> 1) Writing a custom Authenticator to handle that specific situation.
>> This one would look very similar to the ootb X509 authenticator, but
>> implements either a) or b) (see below)
>> 2) Making a contribution to Keycloak and extend the list of available
UserIdentitiyExtractors.
>>
>> For both approaches two different implementations come to my mind:
>>
>> a) Adding an additional UserIdentitiyExtractor which combines the issuer and the
serial number into a single string and use that as an identity.
>> b) Adding an additional UserIdentitiyExtractor which returns the whole
certificate as the user's identity.
>>
>> We would prefer contributing to Keycloak, if such a contribution is welcome and
meaningful.
>>
>> Do you have any advice on which way to go here?
>>
>> [
1]https://github.com/keycloak/keycloak/blob/master/services/src/mai
>> n
>> /java/org/keycloak/authentication/authenticators/x509/UserIdentityEx
>> t
>> ractor.java
>> [
2]https://github.com/keycloak/keycloak/blob/master/services/src/mai
>> n
>> /java/org/keycloak/authentication/authenticators/x509/UserIdentityTo
>> M
>> odelMapper.java#L57
>>
>> Regards
>> Sven-Torben
>>
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