EC_STRUCTURED_SIG_EXPORT_SIZE
u8 st_sig[EC_STRUCTURED_SIG_EXPORT_SIZE(EC_MAX_SIGLEN)];
st_siglen = EC_STRUCTURED_SIG_EXPORT_SIZE(siglen);
MUST_HAVE(EC_STRUCTURED_SIG_EXPORT_SIZE(siglen) <= sizeof(buf), ret, err);
fwrite(buf, 1, EC_STRUCTURED_SIG_EXPORT_SIZE(siglen),
if (written != EC_STRUCTURED_SIG_EXPORT_SIZE(siglen)) {
EC_STRUCTURED_SIG_EXPORT_SIZE(siglen));