https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=56270
unsigned char keydata[32] = {1};
        for (size_t i = 0; i < 256; i++) {
            keydata[31] = i;
            CKey privkey;
            privkey.Set(keydata, keydata + 32, true);
            const Key pubkey = privkey.GetPubKey();
            dummy_keys.push_back(pubkey);
            dummy_key_idx_map.emplace(pubkey, i);
            dummy_keys_map.insert({pubkey.GetID(), pubkey});
            std::vector<unsigned char> sig;