Jun, 11. SCRAM messages have an optional extensions field which is a list of key=value pairs. We can add an extension key to the first client message to indicate delegation token. Broker can then obtain credentials and principal using a different code path for delegation tokens.
On Tue, Nov 8, 2016 at 6:38 PM, Jun Rao <j...@confluent.io> wrote: > Magnus, > > Thanks for the input. If you don't feel strongly the need to bump up the > version of SaslHandshake, we can leave the version unchanged. > > Rajini, > > 11. Yes, we could send the HMAC as the SCRAM password for the delegation > token. Do we need something to indicate that this SCRAM token is special > (i.e., delegation token) so that we can generate the correct > KafkaPrincipal? The delegation token logic can be added later. I am asking > just so that we have enough in the design of SCRAM to add the delegation > token logic later. > > Thanks, > > Jun > > > On Tue, Nov 8, 2016 at 4:42 AM, Rajini Sivaram < > rajinisiva...@googlemail.com > > wrote: > > > Hi Jun, > > > > 10. *s=<salt>* and *i=<iterations>* come from the SCRAM standard (they > are > > transferred during SCRAM auth). Scram messages look like (for example) > > *r=<nonce>,s=<salt>,i=<iterations>*. StoredKey and ServerKey and not > > transferred in SCRAM messages, so I picked two keys that are unused in > > SCRAM. > > > > 11. SCRAM (like DIGEST-MD5 or PLAIN) uses a shared secret/password for > > authentication along with a username and an optional authorization-id. > > Kafka uses the username as the identity (Kafka principal) for > > authentication and authorization. KIP-48 doesn't mention KafkaPrincipal > in > > the section "Authentication using Token", but a delegation token is > > associated with a Kafka principal. Since delegation tokens are acquired > on > > behalf of a KafkaPrincipal and the principal is included in the token as > > the token owner, clients authenticating with delegation tokens could use > > the token owner as username and the token HMAC as shared secret/password. > > > > If necessary, any other form of token identifier may be used as username > as > > well as long as it contains sufficient information for the broker to > > retrieve/compute the principal and HMAC for authentication. The server > > callback handler can be updated when delegation tokens are implemented to > > generate Kafka principal accordingly. > > > > > > On Tue, Nov 8, 2016 at 1:03 AM, Jun Rao <j...@confluent.io> wrote: > > > > > Hi, Rajini, > > > > > > A couple of other questions on the KIP. > > > > > > 10. For the config values stored in ZK, are those keys (s, t, k, i, > etc) > > > stored under scram-sha-256 standard? > > > > > > 11. Could KIP-48 (delegation token) use this KIP to send delegation > > tokens? > > > In KIP-48, the client sends a HMAC as the delegation token to the > server. > > > Not sure how this gets mapped to the username/password in this KIP. > > > > > > Thanks, > > > > > > Jun > > > > > > On Tue, Oct 4, 2016 at 6:43 AM, Rajini Sivaram < > > > rajinisiva...@googlemail.com > > > > wrote: > > > > > > > Hi all, > > > > > > > > I have just created KIP-84 to add SCRAM-SHA-1 and SCRAM-SHA-256 SASL > > > > mechanisms to Kafka: > > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP- > > > > 84%3A+Support+SASL+SCRAM+mechanisms > > > > > > > > > > > > Comments and suggestions are welcome. > > > > > > > > Thank you... > > > > > > > > Regards, > > > > > > > > Rajini > > > > > > > > > > > > > > > -- > > Regards, > > > > Rajini > > > -- Regards, Rajini
