Various fixes and tweaks to permit a gateway to request
signatures from nodes.
The following messages will not be signed (nor verified):
* All signing-related handshake messages
* All ID-related handshake messages
* All ACKs
An important change is that the polarity for the signing request
flags stored in EEPROM has changed. '0' now means signing required.
This ensures that if the "ClearEepromConfig" sketch is executed,
signing requests will be turned off by default.
As a consequence, it is recommended to clear EEPROM if signing will
be used to ensure all nodes default to a non-signing state.
process() altered the message buffer pending signing when
called in sign() causing the wrong message to be sent to the
signing backend. This is resolved by copying the original
message before processing incoming messages to make sure
the original message is kept. After it is successfully signed,
it is copied back to its original location again.
Also, the old 'ack' message buffer is renamed to tmpMsg to
indicate its use as a temporary message buffer for various
purposes.
The dummy signing driver backend is used. But with this commit all
framework logic for managing signed messages in the MySensors
ecosystem is implemented and enables more sophisticated signing
backends to be added later on.
For a sensor (or gateway) that require a gateway to send signed
messages to it, add 'true' as the fifth argument to 'begin'.
The gateway will automatically inform a node of it's signing
requirements as soon as it receivs the nodes signing preference.
It is important to understand that if the gateway require
signing, it will in this implementation only require signing from
nodes that require signing by the gateway.
If the sensor requires signing from another node on the network
which it communicates directly with, it needs to send 'true' in
an internal message of type I_REQUEST_SIGNING.
In a gateway, I_FIND_PARENT_RESPONSE messages was returning as true by
process(). With this commit it will return as false, is this the right
expected behavior?
Henrik Ekblad
Tomas Hozza
tekka
Patrick Fallberg
Marcelo Aquino