IETF standard conformance

libcbor is, generally speaking, a very faithful implementation of IETF RFC 8949 (STD 94). There are, however, some limitations related to the numerical range and precision available in portable C99.

Bytestring length

There is no explicit limitation of indefinite length byte strings. [1] libcbor will not handle byte strings with more chunks than the maximum value of size_t. On any sane platform, such string would not fit in the memory anyway. It is, however, possible to process arbitrarily long strings and byte strings using the streaming decoder.

[1]

https://www.rfc-editor.org/rfc/rfc8949.html#section-3.2.3

“Half-precision” IEEE 754 floats

As of C99 and even C11, there is no standard implementation for 2 bytes floats. libcbor packs them as a float <https://en.cppreference.com/w/c/language/type>. When encoding, libcbor selects the appropriate wire representation based on metadata and the actual value. This applies both to canonical and normal mode.

For more information on half-float serialization, please refer to the section on Half floats.