2:30 a.m.
+1
Having the configuration in adapter (keycloak.json) won't scale also
because REST services (bearer-only clients) will need to verify
signatures by "frontend" clients, but each frontend client can use
different algorithm to sign it's token. So keycloak.json of bearer-only
clients would need to have some configuration map to track all of
this... Also "rotation" of algorithms will be impossible (if
administrator changes the algorithm for client in admin console, the
adapter configuration in keycloak.json will need to be updated and hence
application restarted...)
But I think we don't need to add any new endpoint, but just re-use
existing client registration endpoints for that? OIDC Client
registration has various metadata for clients like
id_token_signed_response_alg, id_token_encrypted_response_alg,
userinfo_signed_response_alg etc. See [1]. Also we have support for
Dynamic client registration management [2], so client applications are
able to "download" the client's metadata from the endpoint.
The specification enforces that requests are authenticated by Client
Registration Access Token. But ATM we also support authentication by
bearer tokens, which is great. When application sees the bearer token
signed/encrypted by unknown algorithm, it can send the request to KC
registration/management endpoint of particular client to download the
client's metadata. This will work fine also for bearer-only clients. The
bearer-only client can parse the token and send the request to the
registration/management endpoint of particular "frontend" client the
token was issued for to determine the right algorithms etc.
[1]
https://openid.net/specs/openid-connect-registration-1_0.html#ClientMetadata
[2] https://tools.ietf.org/html/draft-ietf-oauth-dyn-reg-management-05
Marek
On 26/06/18 18:25, Stian Thorgersen wrote:
I don't really like the idea of having to reconfigure to make the
adapter accept new signature. I know oidc well known endpoint doesn't
have signature algorithm for access token, but we could add one and
have adapters pull from the server what algorithms to accept.
On Tue, 26 Jun 2018, 11:00 Marek Posolda, <mposolda(a)redhat.com
<mailto:mposolda@redhat.com>> wrote:
On 30/05/18 09:35, Stian Thorgersen wrote:
>> I think it might be better to determine which kind of Token Signature
>> Provider be used by not parsing JWS, for example, looking up Client or
>> Realm settings.
>> This PR might have impacts on keycloak's performance because it has
parsed
>> JWS to determine it every time keycloak receives JWS Token.
>>
> On the server-side that is easy. On the adapter side that would probably
> require adding a property to keycloak.json to set the algorithm. In either
> case it should probably default to RSA for existing realms at least, but we
> could consider setting it to ES256 for new realms.
>
+1
Parsing token signature to determine algorithm should be avoided
IMO. AFAIR Some OAuth/OIDC vendors had security issues in the
past, that they parsed the header with "none" algorithm and then
client applications automatically trust unsigned tokens. We should
make sure this is not possible.
Marek