write sequence number

Matt Caswell matt at openssl.org
Thu Sep 26 09:19:26 UTC 2019

On 26/09/2019 06:42, ratheesh kannoth wrote:
> Hi list,
> i am trying to understand write sequence number and read sequence
> number.  Setup is simple client server with tls v1.2.
> when i made write sequence number to 0 (ssl/t1_enc.c -->
> s->s2->write_sequence to 0).  i commented out all increment operate on
> write_sequence number. But  s->s2->read_sequence number is unmodified.

I assume you are using OpenSSL 1.0.2?

s->s2 has nothing to do with TLSv1.2. That's for SSLv2 and has been removed from
later versions. In 1.0.2 you need to be looking at s->s3->write_sequence and
s->s3->write_sequence. It's changed location in later releases.


> But  there is no issue in transmission. Could any one guide me to find
> the sequence number used in write direction, is stored where ?
> -Ratheesh

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