NID_hmacWithSHA256
prf_nid = NID_hmacWithSHA256;
{ NID_sha256, NID_hmacWithSHA256 },
{ EVP_PBE_TYPE_PRF, NID_hmacWithSHA256, -1, NID_sha256, 0 },
{"hmacWithSHA256", "hmacWithSHA256", NID_hmacWithSHA256, 8, &so[5317]},