CC2531: TouchLink Commissioning: Unable To Decrypt Packets

Abhay Joshi

Part Number: CC2531
Other Parts Discussed in Thread: Z-STACK, ,

Hello,

Devices: CC2531EMK ZLL Remote (From Z-Stack Lighting Kit)

I am using the Sample Light application from Z-Stack Lighting. Post rejoin response, there are some packet exchanges which I am unable to decrypt using the ZLL Fixed Network Key (CC:CC:CC:CC:CC:CC:CC:CC). Is there any other key employed?

Also, Why is that Rejoin Request is not an encrypted packet?

over 7 years ago

0 Abhay Joshi over 7 years ago

Intellectual 810 points

TouchLink.cubx.zip

0 JasonB over 7 years ago in reply to Abhay Joshi

TI__Expert 8950 points

Hi,

Your NWK key is all 00:00:00 for some reason. I would recommend completely erasing the flash on your devices, reflashing, and trying again.

As for the Rejoin Request, Zigbee has both Secure Rejoins and Trust Center (unsecure) Rejoins.

0 Abhay Joshi over 7 years ago in reply to JasonB

Intellectual 810 points

Hello Jason,

I am using the ZLL Remote from the CC2531 EM Lighting Kit. It has the default firmware flashed with zero changes from our end. The Network Key obtained from the Scan Request sent by the Remote is CC:CC:CC:CC:CC:CC:CC:CC:CC:CC:CC:CC:CC:CC:CC:CC which corresponds to the TI's Fixed Network Key. Any possible reason as to why the Network Key changed to 00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00?

Is there any firmware patch required for the remote?

0 Abhay Joshi over 7 years ago in reply to JasonB

Intellectual 810 points

Ironically, after a change of battery, it is able to send an encrypted Rejoin Request with the key as CC:CC:CC:CC:CC:CC:CC:CC:CC:CC:CC:CC:CC:CC:CC:CC and all the other following packets are also encrypted with the same key.

There is no change in code, firmware or operational setup. Yet to figure the root cause of the same.

0 JasonB over 7 years ago in reply to Abhay Joshi

TI__Expert 8950 points

Hi,

If VDD drops below 2.0V, there is a chance that NV initialization will not work correctly in our legacy Z-Stack releases. This is a bug which has been patched in our latest Z-Stack 3.0.x releases. Unfortunately, the bug is partially in the core libraries, so I cannot provide a fix on the web. I would recommend migrating to our latest Z-Stack release to avoid this issue.

0 Abhay Joshi over 7 years ago in reply to JasonB

Intellectual 810 points

Hello Jason,

I am able to consistently pair post battery change. Guess the voltage had something to do with it. Thanks for the prompt support.

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CC2531: TouchLink Commissioning: Unable To Decrypt Packets