Don't do that. As I said, the library is trying to tell you that's not a point on the secp256k1 curve.
Quickly browsing the standard, you are likely looking for the prime256v1 curve. BBB On Fri, 25 Oct 2019, 9.28 Luca Di Mauro, <luca.dima...@cnit.it> wrote: > I think it is correct because I extracted the hexadecimal string from > a packet contained in a pcap. > > This compressed point is created following the ETSI TS 103 097 v1.3.1 > standard for secured communications in the vehicular communication > context > ( > https://www.etsi.org/deliver/etsi_ts/103000_103099/103097/01.03.01_60/ts_103097v010301p.pdf > ). > > I notice that the point 'pubPoint' that I created is empty when I try > to call 'EC_POINT_set_compressed_coordinates_GFp' function. How can I > put a BIGNUM into an EC_POINT? > > Luca > > Billy Brumley <bbrum...@gmail.com> ha scritto: > > >> EC_GROUP* group = EC_GROUP_new_by_curve_name > >> (NID_secp256k1); > > > >> "c16b4ce0532f5dc9d09114fe121d3956ae84f9eb677a0d4bdac1d3af7a91950c"; > > > > I don't believe there's a point on secp256k1 with that x-coordinate. > > If you check the failure reason for > > EC_POINT_set_compressed_coordinates_GFp in the debugger, that is > > probably what it is telling you. > > > > Where did this curve / x-coord pair come from? > > > > BBB > > > >