Hi I am right now want to do a make a small tool to generate some test vector for ecdsa. Openssl is quite good, for support secp256k1 bitcoin provides an excellent library.
However, it looks what I get from secp256k1 API only the compressed key. I find some post about how to convert the compressed key (Qx) to uncompressed key (Qx,Qy). But I just wondering if I can directly get the uncompressed key?