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Rob Godfrey commented on PROTON-1135: ------------------------------------- As a co-author of the AMQP specification, I don't think it can be taken as read that every implementation of a "server" MUST support pipelining of the SASL and AMQP layers together. The spec does lay out that the AMQP open sequence can be pipelined, but the SASL interaction is (in general) synchronous: the client must choose from the set of mechanisms offered. In certain circumstances the client (application) may have knowledge that allows it to operate in a pipelined manner (e.g. it knows that the server will accept the mechanism) or may be happy to fail in a reasonably unpleasant way if its assumptions are incorrect. However I think that it is unreasonable to expect that in general a peer will accept pipelining SASL and AMQP together, and empirical evidence shows that it is a poor assumption to make (as literally no other implementation has supported it out of the box). To my mind, in this scenario it would be more appropriate to omit the SASL layer entirely. > [proton-c] dont pipeline SASL and OPEN frames for ANONYMOUS logins by default > ----------------------------------------------------------------------------- > > Key: PROTON-1135 > URL: https://issues.apache.org/jira/browse/PROTON-1135 > Project: Qpid Proton > Issue Type: Bug > Components: proton-c > Affects Versions: 0.12.0 > Reporter: Ganesh Murthy > > Dispatch router (which uses Proton-c) currently sends pipelined SASL and OPEN > frames by default when connecting out to other peers using the ANONYMOUS > mech, as shown in the following trace - > {code} > [0x7f41f80079c0]: -> SASL > [0x7f41f80079c0]:0 -> @sasl-init(65) [mechanism=:ANONYMOUS, > initial-response=b"anonymous@localhost.localdomain"] > [0x7f41f80079c0]: -> AMQP > [0x7f41f80079c0]:0 -> @open(16) [container-id="Qpid.Dispatch.Router.A", > max-frame-size=65536, channel-max=32767, idle-time-out=8000, > offered-capabilities=:"ANONYMOUS-RELAY", > properties={:product="qpid-dispatch-router", :version="0.6.0"}] > [0x7f41f80079c0]: <- SASL > [0x7f41f80079c0]:0 <- @sasl-mechanisms(64) [sasl-server-mechanisms=:ANONYMOUS] > [0x7f41f80079c0]:0 <- @sasl-outcome(68) [code=0] > [0x7f41f80079c0]: <- AMQP > [0x7f41f80079c0]:0 <- @open(16) > [container-id="ce103199-af03-4d37-bb35-24ad4e55653e", channel-max=32767, > idle-time-out=8000, offered-capabilities=@PN_SYMBOL[:"ANONYMOUS-RELAY"], > properties={:product="qpid-cpp", :version="0.35", :platform="Linux", > :host="localhost.localdomain"}] > {code} > The AMQP 1.0 spec does not make it clear that this is supported (e.g. see > diagram below) but in any case various components have shown difficulty with > it (such as PROTON-1135 just raised, and QPID-6639 which has yet to be > included in a release but permitted the above protocol trace log). > {code} > TCP Client TCP Server > ========================================= > AMQP%d3.1.0.0 ---------> > <--------- AMQP%d3.1.0.0 > : > : > <SASL negotiation> > : > : > AMQP%d0.1.0.0 ---------> > (over SASL secured connection) > <--------- AMQP%d0.1.0.0 > open ---------> > <--------- open > {code} > Proton should by default disable sending pipelined OPEN frames for ANONYMOUS > logins, to aid compatibility with other components that don't expect/handle > such behaviour. -- This message was sent by Atlassian JIRA (v6.3.4#6332)