[openssl/openssl] 9cdee3: Correctly handle a retransmitted ClientHello

[Matt Caswell]

  Branch: refs/heads/openssl-3.0
  Home:   https://github.com/openssl/openssl
  Commit: 9cdee31c892e8abe0048b69fddca53d8e0da8380
      https://github.com/openssl/openssl/commit/9cdee31c892e8abe0048b69fddca53d8e0da8380
  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)

(cherry picked from commit 81926c91567cd5d11eec38b9980438f45b276d72)


  Commit: 290c1d8d629636f57e938bd8328dc6c8f98c4752
      https://github.com/openssl/openssl/commit/290c1d8d629636f57e938bd8328dc6c8f98c4752
  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)

(cherry picked from commit a29ad912b82f50ef876bef99c66522dccd41b6f8)


Compare: https://github.com/openssl/openssl/compare/33796db4a5c3...290c1d8d6296