[prev in list] [next in list] [prev in thread] [next in thread] 

List:       cfrg
Subject:    Re: [CFRG] Reference for weakness in MAC=hash(key|msg) construct
From:       Yann Droneaud <ydroneaud () opteya ! com>
Date:       2022-05-15 18:01:46
Message-ID: 7c947ad7-465a-6cc4-0ca8-03fb6d89c7bf () opteya ! com
[Download RAW message or body]

Hi,

Le 13/05/2022 à 16:24, Robert Moskowitz a écrit :
> 
> I need to show that a MAC based on hash(key|msg) is bad and this has 
> been known since the mid-90s.
> 
> This is for the Drone Command and Control (C2) open protocol MAVlink's 
> 6 byte authentication:
> 
> https://mavlink.io/en/guide/message_signing.html
> 

Cryptography in MAVlink is somewhat a weak point. Last year I've noted 
the following:

Believe it or not but cryptography is about making things hidden ... so 
putting a symmetric key in clear in source file available on github is 
probably defeating the whole purpose of using cryptography:

     PairingManager::PairingManager(QGCApplication* app, QGCToolbox* toolbox)

     : QGCTool(app, toolbox)

     , _aes("J6+KuWh9K2!hG(F'", 0x368de30e8ec063ce)


https://github.com/mavlink/qgroundcontrol/blob/cc95825594fc99e7537198003cab4a0dd1172bcb/src/PairingManager/PairingManager.cc#L43



https://twitter.com/ydroneaud/status/1361421701179797504


-- 

Yann Droneaud

OPTEYA


_______________________________________________
CFRG mailing list
CFRG@irtf.org
https://www.irtf.org/mailman/listinfo/cfrg


[prev in list] [next in list] [prev in thread] [next in thread]