static int rsa_item_verify(EVP_MD_CTX *ctx, const ASN1_ITEM *it, void *asn,
                           X509_ALGOR *sigalg, ASN1_BIT_STRING *sig,
                           EVP_PKEY *pkey)
{
    /* Sanity check: make sure it is PSS */
    if (OBJ_obj2nid(sigalg->algorithm) != NID_rsassaPss) {
        RSAerr(RSA_F_RSA_ITEM_VERIFY, RSA_R_UNSUPPORTED_SIGNATURE_TYPE);
        return -1;
    }
    if (rsa_pss_to_ctx(ctx, NULL, sigalg, pkey) > 0) {
        /* Carry on */
        return 2;
    }
    return -1;
}

Unknown