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Bug 1238674

Summary: Problems decoding TLS Server Key Exchange messages
Product: Red Hat Enterprise Linux 6 Reporter: Jaroslav Aster <jaster>
Component: wiresharkAssignee: Martin Sehnoutka <msehnout>
Status: CLOSED DUPLICATE QA Contact: BaseOS QE Security Team <qe-baseos-security>
Severity: medium Docs Contact:
Priority: medium    
Version: 6.8   
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: 1222600 Environment:
Last Closed: 2016-07-20 06:45:18 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Jaroslav Aster 2015-07-02 11:50:31 UTC
The same issue on rhel-6.

# rpm -q wireshark
wireshark-1.8.10-17.el6.x86_64

# tshark -o 'ssl.desegment_ssl_records:TRUE' -d tcp.port==4433,ssl -r capture-selfsrv-nss-3.16.2.3-el7.pcap -V | grep -A 6 'Server Key Exchange'
Running as user "root" and group "root". This could be dangerous.
        Handshake Protocol: Server Key Exchange
            Handshake Type: Server Key Exchange (12)
            Length: 199
        Handshake Protocol: Server Hello Done
            Handshake Type: Server Hello Done (14)
            Length: 0

+++ This bug was initially created as a clone of Bug #1222600 +++

Description of problem:
If the connection uses TLSv1.2 the Wireshark GUI can't decode the TLS Handshake Protocol Server Key Exchange messages in ECDHE key exchange, it can do that only if the connection uses TLSv1.0.

Decoding of Server Key Exchange using the CLI tshark command always fails

Version-Release number of selected component (if applicable):
wireshark-1.10.3-12.el7_0.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Open wireshark load sigalgs.pcapng

1. tshark -o 'ssl.desegment_ssl_records:TRUE' -d tcp.port==4433,ssl -r /tmp/capture-selfsrv-nss-3.16.2.3-el7.pcap -V | grep -A 6 'Server Key Exchange'

Actual results:
        Handshake Protocol: Server Key Exchange
            Handshake Type: Server Key Exchange (12)
            Length: 199

Expected results:
        Handshake Protocol: Server Key Exchange
            Handshake Type: Server Key Exchange (12)
            Length: 199
            EC Diffie-Hellman Server Params
                curve_type: named_curve (0x03)
                named_curve: secp256r1 (0x0017)
                Pubkey Length: 65
                pubkey:
etc.

Additional info:

--- Additional comment from Hubert Kario on 2015-05-19 07:51:21 EDT ---

Wireshark GUI can't also decode Server Key Exchange with DHE-RSS and DHE-DSS key exchange in TLSv1.2.

tshark can't decode DHE or ECDHE key exchange, be it with RSA, DSS or ECDSA authentication and in TLSv1.0 or TLSv1.2

(omitting TLSv1.1 as it has the same message format as TLSv1.0)

Comment 3 Martin Sehnoutka 2016-07-20 06:45:18 UTC

*** This bug has been marked as a duplicate of bug 1222895 ***