Magnus,

It sounds like KIP-43 will need to change in order to support the KIP-35
protocol. Can you add more details on what you had in mind?

On Mon, Apr 4, 2016 at 12:41 PM, Magnus Edenhill <mag...@edenhill.se> wrote:

> As Jun says the SASL (and SSL) handshake is not done using the Kafka
> protocol
> and is performed before any Kafka protocol requests pass between client and
> server.
>
> It might make sense to move the SASL handshake from its custom protocol
> format
> into the Kafka protocol and make it use the proper Kafka protocol framing.
>
> (For SSL this is isnt needed since TLS has its own _standardised_
> hand-shake format and existing SSL implementations take care of it.)
>
> 2016-04-04 21:20 GMT+02:00 Ismael Juma <ism...@juma.me.uk>:
>
> > An option would be to add a version for the handshake in the KIP-35
> > response.
> >
> > Ismael
> > On 4 Apr 2016 20:09, "Gwen Shapira" <g...@confluent.io> wrote:
> >
> > > I think the challenge here is that even after KIP-35 clients will not
> > know
> > > whether the server supports new sasl mechanisms or not, so non-Java
> > clients
> > > will have to assume it is not supported (and will therefore lag behind
> on
> > > features).
> > >
> > > I think this highlights a short-coming of KIP-35, and I'm wondering if
> > > there are good ways to address this.
> > >
> > > Gwen
> > >
> > >
> > > On Mon, Apr 4, 2016 at 12:05 PM, Jun Rao <j...@confluent.io> wrote:
> > >
> > > > I think with KIP-43, the existing way of sasl handshake during
> > connection
> > > > still works. It's just that if you want to support non-GSSAPI, you
> will
> > > > need a new sasl handshake implementation in the client. It's
> > unfortunate
> > > > that Protocol currently only covers the communication after the
> > > connection
> > > > is ready to use, but not during handshake. For now, we can probably
> > just
> > > > document this change during handshake since changing the
> implementation
> > > is
> > > > optional.
> > > >
> > > > Thanks,
> > > >
> > > > Jun
> > > >
> > > > On Mon, Apr 4, 2016 at 11:28 AM, Gwen Shapira <g...@confluent.io>
> > wrote:
> > > >
> > > > > Hi Kafka Team,
> > > > >
> > > > > As a practical test-case of KIP-35, I'd like to turn your attention
> > to
> > > > > KIP-43:
> > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-43
> > > > >
> > > > > KIP-43 makes an interesting modification to the protocol, but only
> > > under
> > > > > specific conditions:
> > > > >
> > > > > "*Client flow:*
> > > > >
> > > > >    1. If sasl.mechanism is not GSSAPI, send a packet with the
> > mechanism
> > > > >    name to the server. Otherwise go to Step 3.
> > > > >       - Packet Format: | Version (Int16) | Mechanism (String) |
> > > > >    2. Wait for response from the server. If the error code in the
> > > > response
> > > > >    is non-zero, indicating failure, report the error and fail
> > > > > authentication.
> > > > >    3. Perform SASL authentication with the configured client
> > mechanism
> > > > >
> > > > > *Server flow:*
> > > > >
> > > > >    1. Wait for first authentication packet from client
> > > > >    2. If this packet is a not valid mechanism request, go to Step 4
> > and
> > > > >    process this packet as the first GSSAPI client token
> > > > >    3. If the client mechanism received in Step 2 is enabled in the
> > > > broker,
> > > > >    send a response with error code zero and start authentication
> > using
> > > > the
> > > > >    specified mechanism. Otherwise, send an error response including
> > the
> > > > > list
> > > > >    of enabled mechanisms and fail authentication.
> > > > >    - Packet Format: | ErrorCode (Int16) | EnabledMechanisms
> > > > > (ArrayOf(String))
> > > > >       |
> > > > >    4. Perform SASL authentication with the selected mechanism. If
> > > > mechanism
> > > > >    exchange was skipped, process the initial packet that was
> received
> > > > from
> > > > > the
> > > > >    client first."
> > > > >
> > > > >
> > > > > I'd love to know how this will be communicated to clients via
> > > > > VersionRequest proposed in KIP-35 (mostly because Jun and I need to
> > > > review
> > > > > KIP-43 and we want to be sure we are not breaking the new protocol
> at
> > > the
> > > > > same time we introduce it)
> > > > >
> > > > > Do we:
> > > > > 1. Bump protocol version of every single Request? Even though
> unless
> > > you
> > > > > are using a new sasl mechanism nothing changes?
> > > > > 2. Ignore and not bump protocol? If so, how will clients know that
> > new
> > > > > sasl.mechanisms are supported?
> > > > > 3. Something else?
> > > > >
> > > > > Gwen
> > > > >
> > > >
> > >
> >
>

Reply via email to