Wireshark-commits: [Wireshark-commits] master-3.2 e7e52e9: DTLS: try harder to decrypt broken trace

From: Wireshark code review <code-review-do-not-reply@xxxxxxxxxxxxx>
Date: Wed, 29 Apr 2020 20:35:13 +0000
URL: https://code.wireshark.org/review/gitweb?p=wireshark.git;a=commit;h=e7e52e9b0d35e9d7eb7eddfa3bc027ace0dfece6
Submitter: "Peter Wu <peter@xxxxxxxxxxxxx>"
Changed: branch: master-3.2
Repository: wireshark

Commits:

e7e52e9 by Peter Wu (peter@xxxxxxxxxxxxx):

    DTLS: try harder to decrypt broken traces with double CCS
    
    A retransmitted ChangeCipherSpec could result in resetting the cipher.
    The subsequent Finished message and application data messages would
    therefore fail to decrypt. In legitimate TLS sessions, there should not
    be a CCS without starting a new handshake, so that remains unaffected.
    
    To ease debugging this issue, log the packet number and add some extra
    details to the debug log. Move or remove ssl_packet_from_server calls to
    avoid redundant work and to keep the debug log cleaner.
    
    Additionally, try harder to dissect handshake messages if we know for
    sure that they are decrypted. This allows inspection of a broken
    Finished message that had a too large fragment length.
    
    Tested with a private capture file from Stig Bjørlykke.
    
    Change-Id: If6f15f8b72c467ea9ef15ddcaf2c5ebe980c27c8
    Reviewed-on: https://code.wireshark.org/review/36929
    Petri-Dish: Peter Wu <peter@xxxxxxxxxxxxx>
    Tested-by: Petri Dish Buildbot
    Reviewed-by: Stig Bjørlykke <stig@xxxxxxxxxxxxx>
    Reviewed-by: Anders Broman <a.broman58@xxxxxxxxx>
    (cherry picked from commit 17298cc0fbe1655ee07db54457f476f0799b8152)
    Reviewed-on: https://code.wireshark.org/review/36974
    Reviewed-by: Peter Wu <peter@xxxxxxxxxxxxx>
    

Actions performed:

    from  d863846   capinfos: fix absolute and relative time display.
     add  e7e52e9   DTLS: try harder to decrypt broken traces with double CCS


Summary of changes:
 epan/dissectors/packet-dtls.c      | 50 ++++++++++++++++++++------------------
 epan/dissectors/packet-tls-utils.c | 14 +++++------
 2 files changed, 33 insertions(+), 31 deletions(-)