Verify signature (ECDSA_do_verify) using only x-coordinate in public key (EC_POINT)?

[Jonas Andersson]

Hi all,

Is there a way to verify a signature with ECDSA_do_verify having only the
x-coordinate (in public key) available?

I am trying to verify a signature using "ECDSA_do_verify":
ECDSA_do_verify(dgst, dgst_len, signature, eckey_nistp256);

, where the eckey_nistp256 is given from:
EC_KEY_set_public_key(eckey_nistp256, ecpoint_nistp256);

and only the x part of ecpoint_nistp256 is available.

When trying to verify, this function returns -1.
(I have verified that the digest and signature are correct).

Thanks in advance.

Best regards
/Jonas