Other Parts Discussed in Thread: Z-STACK
Hi,
I have a working implementation of an ESP and an IPD with the Ember stack using Smart Energy Security. I now want to re-implement the IPD using ZStack-EXP5438-2.3.0-1.4.0 (on different hardware clearly), but am hitting a roadblock. The ESP is still running the Ember stack.
I have followed the instructions in "Smart Energy Sample Application User's Guide" (SWRU215) to set up the IEEE, Device Implicit Cer, Device Private Key and CA Pub Key. But I have been unable to find documentation on how to configure the install code, or equivalently the preconfigured key in ZStack.
For reference, the over-the-air interaction I got when using Ember stack on both ESP and IPD follows (the IPD's preconfigured link key is set out-of-bands):
IPD => MAC: Association Request
ESP => MAC: Association Response
ESP => APS Command: Key-transport key: Transport Key
IPD => ZDP: Device_annce
ESP => ZDP: Device_annce (broadcast)
IPD => ZDP: Match_Desc_req
ESP => ZDP: Match_Desc_rep
ESP => APS Acknowledgement
IPD => APS Acknowledgement
IPD => SE: Key Establishment
etc...
Indeed this is largely the same as the Daintree SNA example in SWRU215.
With the same Ember ESP, but with the [still broken?] ZStack IPD:
IPD => MAC: Association Request
ESP => MAC: Association Response
ESP => APS Command: Key-transport key: Transport Key
and then nothing.
Stepping through the code, whenever the ESP sends the current network key, encrypted with the IPD's pre-configured link key, the stack trace is [at least]
APSME_FrameSecRemoveCM()
APSME_FrameSecurityRemove()
NLDE_DataIndication()
nwk_data_ind_processing()
nwk_sys_event_processing()
nwk_event_loop()
osal_start_system()
main()
This suggests that the IPD is at least trying to decipher the encrypted payload. Of course, since the install code or equivalently the preconfigured link key is not properly written, the network key cannot be propagated to the IPD, and thus CBKE cannot start.
For more information on Smart Energy Key Establishment, see http://portal.ember.com/faq/se-key-establishment
See also http://www.ember.com/pdf/120-5058-000_SettingManufacturingCertificates.pdf, for the steps involved to configure the IEEE, Device Implicit Cer, Device Private Key, CA Pub Key *AND* the install code.
In case the question is lost in this post, I repeat: How do I write a preconfigured link key into ZStack? (Preferably into non-volatile memory).
Thanks.
Voon
