Trouble to verify ECDSA signature, NIST P-256

[Yann Garcia]

Dear All,

I got issue (gcrypt/Not implementedgcrypt/Not implemented) will verifying a
signature. I have the public key, the signature and the curve.

I proceed in the following way:
1) Build public key


 q=hex_to_data("AC529F186F485D194EBE3677EA9FD1D7E7280648081A01686B3E78528D8AA5C6DC44DB3E54EEF45BA7EE989572D1DC0F83FF071E30B1EE5972D52D22D204A0AD",
&q_size);
if ((rc = gcry_sexp_build (&public_key, NULL, "(ecc(curve \"NIST P-256\")(q
%b))\n", q_size, q)) != 0) {
      printf("Failed for %s/%s\n", gcry_strsource(rc), gcry_strerror(rc));
      ....
    }

2) Create a context based on the public key


if (0 != (rc = gcry_mpi_ec_new(&ctx, public_key, "NIST P-256"))) {
      printf("Failed for %s/%s\n", gcry_strsource(rc), gcry_strerror(rc));
      ....
    }

And here was the issue: I got the error message "gcrypt/Not implemented"

Can anyone provide me some hints to fix it, I have no idea how to proceed
here?

Many thanks in advance for your help,

Best regards,
Yann Garcia
Senior Software Engineer
Microsoft MCAD.net Certified
**************************************
FSCOM SARL
Le Montespan B2
6,
<https://maps.google.com/?q=6,%C2%A0+Avenue+des+Alpes&entry=gmail&source=g>
Avenue des Alpes
<https://maps.google.com/?q=6,%C2%A0+Avenue+des+Alpes&entry=gmail&source=g>
F-06600 Antibes, FRANCE
************************************************
Tel: +33 (0)4 92 94 49 08
Mobile: +33 (0)7 61 00 77 05
Email: *yann.garcia at fscom.fr* <yann.garcia at fscom.fr>
           Yann.Garcia_EXT at etsi.org
Skype: yann.garcia
Google+: garcia.yann at gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.gnupg.org/pipermail/gcrypt-devel/attachments/20181125/a4596c77/attachment.html>