OpenSSL::Netscape::SPKI#challenge

static VALUE
ossl_spki_get_challenge(VALUE self)
{
    NETSCAPE_SPKI *spki;

    GetSPKI(self, spki);
    if (ASN1_STRING_length(spki->spkac->challenge) <= 0) {
        OSSL_Debug("Challenge.length <= 0?");
        return rb_str_new(0, 0);
    }

    return asn1str_to_str(spki->spkac->challenge);
}