Below is the original README for cn-cbor, a Proof of Concept implementation of CBOR that I wrote in 2013. People have been sending me fixes and updates to make this implementation more useful for actual use, and for a while I have occasionally integrated them. Jim Schaad now is so far ahead of this repo that you are most likely better off using his repo as your upstream.
If you are here looking for experimental CBOR implementations for constrained nodes, there are many, some of which are listed at cbor.io. One more: I have recently extracted the implementation from ARM-mbed's SUIT manifest generator (Apache 2.0). SUIT implementers report (CBOR-specific) code sizes in the low hundreds of bytes. Thank you, ARM.
This is a constrained node implementation of CBOR in C that I threw together in 2013, before the publication of RFC 7049, to validate certain implementability considerations.
Its API model was inspired by nxjson. It turns out that this API model actually works even better with the advantages of the CBOR format.
This code has been used in a number of research implementations on constrained nodes, with resulting code sizes appreciably under 1 KiB on ARM platforms.
I always meant to improve the interface some more with certain API changes, in order to get even closer to 0.5 KiB, but I ran out of time. So here it is. If I do get around to making these changes, the API will indeed change a bit, so please be forewarned.
There is a Simple-Makefile for playing around, as well as a complete cmake-based build environment. (You can choose what fits your needs better.)
Building with cmake:
./build.sh
Building including testing:
./build.sh all test
Generating a test coverage report (requires lcov[^1]; result in build/lcov/index.html):
./build.sh all coveralls coverage_report
License: MIT
[^1]: Installation with homebrew: brew install lcov