Size of public key‘s in „Raw-Public Key mode“

[boaks]

The TS 20150228 mentions in E1.1.2 „Thus the Certificate Resource would contain a 32 byte public key and the Secret Key Resource a 32 byte private key.“ But ECC uses two public keys (“x” and “y”) each of 32 bytes. Should public key x and public key y be stored concatenated (xy, 64 bytes) in the "public keys" resources?

[BillBennett]

Also, doesn't the size vary with different curves? CoAP specifies "curve secp256r1 MUST be supported" - does that mean that keys for other curves MUST NOT be used? Is that risky?

[BillBennett]

Also also, I think the PSK is variable-length because it gets hashed. That means "The default PSK Cipher Suites defined in this specification use a 128-bit AES key. Thus this key would be represented in 16 bytes in the Secret Key Resource." is also misleading.

[boaks]

There is already an open issue on the PSK length.

See https://github.com/OpenMobileAlliance/OMA-LwM2M-Public-Review/issues/4

[BillBennett]

Whoops. Thanks!

[boaks]

OMA-TS-LightweightM2M-V1_0-20160407-C, E.1.1.2

Still defines 32 bytes!

[hannestschofenig]

Resolution for the incorrect length indication is to delete the following sentence from Appendix E1.1.2:

„Thus the Certificate Resource would contain a 32 byte public key and the Secret Key Resource a 32 byte private key.“

Reason for change: The statement is incorrect, as also pointed out in issue#48:https://github.com/OpenMobileAlliance/OMA_LwM2M_for_Developers/issues/48

Affected version: LWM2M v1.0

[ThGarnier]

solved in TS 1.0 Sept 2016 release

[Megan-OMA]

Issue closed per Thierry's comment above 11-Oct-2016