[openssl-users] Root-Level queries while using SSL-connections wrapping "sockets"

[Ajay Garg]

Hi All.

I guess all my theories are bang on, as the entire framework was integrated
seamlessly making use of the above "theories".

Thanks a ton to everyone, and extra thanks to Viktor 😊

Thanks and Regards,
Ajay

On 10 Oct 2016 6:34 a.m., "Ajay Garg" <ajaygargnsit at gmail.com> wrote:

> Thanks Michael for the reply.
>
> And yes, your points are absolutely valid.
>
> We do not assume anything at the client/server as such, we just read
> the byte-streams, and generate (MQTT) packets out of bytestreams as
> and when the starting- and ending- boundaries of a (new) MQTT-packet
> are received.
>
>
> Still, I believe all my 3 questions (step a, step b, and the 8-point
> story in step c) are independent of this, and would like to hear from
> you experts as to if my understanding of all those 3 steps is correct,
> including the all important assumption
>
> *Implicit in this workflow is my assumption that SSL too builds up a
> packet for every BIO_write done over "bio1". *
>
> I say it the most important, because our application is MQTT-based,
> and all our communication is request/response based; we send a packet,
> and expect an acknowledgement.
>
> In other words, if my implicit assumption is correct, then every
> "BIO_write(bio1)" would generate a complete SSL-packet, which would be
> available at "bio2" instantly and synchronously - ready to be
> transferred over the wire.
>
>
> Again, would be thankful from the bottom of my heart, to hear
> confirmations/rejections regarding my theories in step a), step b) and
> 8-point-story in step c) as per my previous email.
>
>
>
> Thanks and Regards,
> Ajay
>
> On Mon, Oct 10, 2016 at 2:39 AM, Michael Wojcik
> <Michael.Wojcik at microfocus.com> wrote:
> >> From: openssl-users [mailto:openssl-users-bounces at openssl.org] On
> Behalf
> >> Of Ajay Garg
> >> Sent: Sunday, October 09, 2016 14:12
> >>
> >> Also, for all my cases, Nagle's algorithm has been disabled on the
> >> client as well as the server, so every write (at client/server)
> >> constitutes a packet-transferred.
> >
> > This assumption is incorrect. Nagle is not the only factor which
> interferes with a 1-to-1 mapping between application sends and (IP) packets
> on the wire. The peer's receive window, the interface and path MTUs,
> fragmentation, transient network failures ... many  things can either split
> an application message into multiple IP packets or even multiple TCP
> segments, or cause multiple application messages to be coalesced into a
> single TCP segment (which usually is also a single IP packet, now that path
> MTU determination usually works properly).
> >
> > You should never assume TCP is anything other than a byte-stream
> service. An application that makes any assumptions about how its send
> operations translate into TCP segments or IP packets is asking for trouble.
> >
> > --
> > Michael Wojcik
> > Distinguished Engineer, Micro Focus
> >
> >
> >
> > --
> > openssl-users mailing list
> > To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users
>
>
>
> --
> Regards,
> Ajay
>
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