pkg: add cn-cbor CBOR implementation

[kaspar030]

From https://github.com/cabo/cn-cbor: "A constrained node implementation of CBOR in C".

[aabadie]

should be child.expect_exact if you keep the brackets.

[jnohlgard]

There is a test vector included with the library, so you think it would be possible to work it into the RIOT test application to make it possible to verify the implementation on the actual device?
This module will likely be a useful part for future OTA firmware update solutions, and it is important that it's possible to verify the implementation.

[miri64]

I agree with @gebart to use the test vector for testing.

[kaspar030]

There is a test vector included with the library, so you think it would be possible to work it into the RIOT test application to make it possible to verify the implementation on the actual device?

I guess so, but the code is far from RIOT compliant. Honestly, I don't have time to adapt/integrate that. Any volunteers?

[lorenz9314]

I guess so, but the code is far from RIOT compliant. Honestly, I don't have time to adapt/integrate that. Any volunteers?

We from the Beduino Project would actually be interested in seeing cn-cbor in RIOT and are willing to spend some effort on this. What exactly do you mean by "not RIOT compliant"? The Test, -vectors, cn-cbor in general?

[kaspar030]

What exactly do you mean by "not RIOT compliant"? The Test, -vectors, cn-cbor in general?

I'm talking about the tests. For coding convention reasons, they cannot simply be copied into RIOT's unittests, but would need quite some rework. Maybe it would be simpler to write a couple of new unittests (testing cn-cbors basic functionality) from scratch.

(API-)-style-wise, cn-cbor is not very RIOTy, but as it is just a library that we'd like to support as a package, it doesn't matter.

[smlng]

@kaspar030 can you look into this again, seems others are interested in this too. However, Murdock is a bit unhappy ...

[kaspar030]

closed in favor of #8467.