[Documentation] Source Node Id during comissioning

[lava]

Documentation issues

The Matter specification states in 4.13.1.2. Protocol Details that for all PASE messages

The S Flag and DSIZ fields of the Message Flags SHALL be set to 0.

On the other hand, PASE messages are sent unencrypted and thus according to 4.12.1.1. Unsecured Session Context the initiator should "enclose" (?) an ephemeral node id as the source node id:

Ephemeral Initiator Node ID: Randomly selected for each session by the initiator from the Oper­ational Node ID range and enclosed by initiator as Source Node ID and responder as Destination Node ID.

This seems to be a contradiction, since a message cannot include a source node id if the S flag is set to 0.

Empirically, chip-tool ignores the first requirement and just sets the S flag to 1 for the PBKDFParamRequest message.

So, two questions:

1. Is this the intended behavior?
2. If yes, is it a bug in the Matter specification or did I miss some other paragraph that reconciles the two?

Platform

No response

Anything else?

No response