Hi, Ron
Sorry for the extra delayed answer (I had to switch to another project).
The x and y points are encoded as OCTET STRING (see [1] and [2]) so I believe I meant section 2.3.4 of SEC1.
In this case, mbedtls_ecp_point_read_string() should work, right?
[1] RFC 5480: Elliptic Curve Cryptography Subject Public Key Information
[2] RFC 8152: CBOR Object Signing and Encryption (COSE)
Thanks,
Doru