Added support for device certificate chain in leshan-lwm2m-client module

[jakubsobolewskisag]

PR Description

LwM2m 1.2 specification allows devices to send/use X.509 certificate chains in the Security object and therefore in communication with LwM2m servers (and bootstrap servers). To prepare for this, Leshan client library can already use certificate chains in a backwards-compatible way. This change allows client implementations to use certificate chains.

[sbernard31]

Thx for the PR.
As this is a bit out of scope, I created an issue to discuss about that : #1710

[sbernard31]

I pushed some more code to limit usage of DER encoding by default.
The code should allow to provide custom ServersInfoExtractor for Client and ConfigurationChecker for Bootstrap Server.

I will probably add some more commit to clean old code following sonar advice (I prefer to do that separately to keep commit readable).

Maybe out of scope of that PR :

• Maybe it would make sense to create a utility class for Tests to handle certificates/files in src/test/resouces
• ServersInfoExtractor it is now dynamic but I need to double check if the way we access to it is OK 🤔
• I also notice that there is a problem in objectTree with objectEnabler initialization using LwM2mObjectTree.addObjectEnabler(LwM2mObjectEnabler). It seems that enabler.init(client, linkFormatHelper, serversInfoExtractor); is not called and I think it should (I need to double check that)
• some constructor have too much arguments we should find a way to make this cleaner.

I will be out of office next week back Tuesday 21th.

[sbernard31]

I did :

• Maybe it would make sense to create a utility class for Tests to handle certificates/files in src/test/resouces

For that ones, I will do that in another PR :

• ServersInfoExtractor it is now dynamic but I need to double check if the way we access to it is OK 🤔
• I also notice that there is a problem in objectTree with objectEnabler initialization using LwM2mObjectTree.addObjectEnabler(LwM2mObjectEnabler). It seems that enabler.init(client, linkFormatHelper, serversInfoExtractor); is not called and I think it should (I need to double check that)
• some constructor have too much arguments we should find a way to make this cleaner.

@jakubsobolewskisag, if you want you can review this PR and test if that solves your issue.

[sbernard31]

(ignore the legal agreements issue, I suspect that eclipse infra is partially down)

[sbernard31]

@jakubsobolewskisag finally I also did :

• ServersInfoExtractor it is now dynamic but I need to double check if the way we access to it is OK 🤔
• I also notice that there is a problem in objectTree with objectEnabler initialization using LwM2mObjectTree.addObjectEnabler(LwM2mObjectEnabler). It seems that enabler.init(client, linkFormatHelper, serversInfoExtractor); is not called and I think it should (I need to double check that)

in this PR.

Note that for first point, I slip ServersInfoExtractor in an interface + default implementation and a static class ObjectTreeReader. (better seperation of concerns)

I don't touch anything more until I get you feeback 🙂

[jakubsobolewskisag]

@sbernard31 Thank you! I will check that next week, since I'm on PTO now ;)

[sonarqubecloud]

Quality Gate passed

Issues
6 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sbernard31]

(Please note that I will be unavailable for most of the month, so replies may be delayed 😅 )