[openssl/openssl] 81926c: Correctly handle a retransmitted ClientHello

[Matt Caswell]

  Branch: refs/heads/master
  Home:   https://github.com/openssl/openssl
  Commit: 81926c91567cd5d11eec38b9980438f45b276d72
      https://github.com/openssl/openssl/commit/81926c91567cd5d11eec38b9980438f45b276d72
  Author: Matt Caswell <matt at openssl.org>
  Date:   2022-09-22 (Thu, 22 Sep 2022)

  Changed paths:
    M ssl/statem/statem_dtls.c

  Log Message:
  -----------
  Correctly handle a retransmitted ClientHello

If we receive a ClientHello and send back a HelloVerifyRequest, we need
to be able to handle the scenario where the HelloVerifyRequest gets lost
and we receive another ClientHello with the message sequence number set to
0.

Fixes #18635

Reviewed-by: Tomas Mraz <tomas at openssl.org>
Reviewed-by: Hugo Landau <hlandau at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18654)


  Commit: a29ad912b82f50ef876bef99c66522dccd41b6f8
      https://github.com/openssl/openssl/commit/a29ad912b82f50ef876bef99c66522dccd41b6f8
  Author: Matt Caswell <matt at openssl.org>
  Date:   2022-09-22 (Thu, 22 Sep 2022)

  Changed paths:
    M test/dtlstest.c

  Log Message:
  -----------
  Add additional messages to the DTLS dropped records test

Ensure we are testing a handshake that includes a HelloVerifyRequest and
what happens if we drop it.

Reviewed-by: Tomas Mraz <tomas at openssl.org>
Reviewed-by: Hugo Landau <hlandau at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18654)


Compare: https://github.com/openssl/openssl/compare/0ff98137445e...a29ad912b82f