Reserve proof
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stoffu
@@ -7947,6 +7947,251 @@ bool wallet2::check_tx_proof(const crypto::hash &txid, const cryptonote::account
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return false;
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}
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std::string wallet2::get_reserve_proof(const boost::optional<std::pair<uint32_t, uint64_t>> &account_minreserve, const std::string &message)
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{
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THROW_WALLET_EXCEPTION_IF(m_watch_only || m_multisig, error::wallet_internal_error, "Reserve proof can only be generated by a full wallet");
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THROW_WALLET_EXCEPTION_IF(balance_all() == 0, error::wallet_internal_error, "Zero balance");
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THROW_WALLET_EXCEPTION_IF(account_minreserve && balance(account_minreserve->first) < account_minreserve->second, error::wallet_internal_error,
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"Not enough balance in this account for the requested minimum reserve amount");
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// determine which outputs to include in the proof
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std::vector<size_t> selected_transfers;
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for (size_t i = 0; i < m_transfers.size(); ++i)
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{
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const transfer_details &td = m_transfers[i];
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if (!td.m_spent && (!account_minreserve || account_minreserve->first == td.m_subaddr_index.major))
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selected_transfers.push_back(i);
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}
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if (account_minreserve)
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{
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// minimize the number of outputs included in the proof, by only picking the N largest outputs that can cover the requested min reserve amount
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std::sort(selected_transfers.begin(), selected_transfers.end(), [&](const size_t a, const size_t b)
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{ return m_transfers[a].amount() > m_transfers[b].amount(); });
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while (selected_transfers.size() >= 2 && m_transfers[selected_transfers[1]].amount() >= account_minreserve->second)
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selected_transfers.erase(selected_transfers.begin());
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size_t sz = 0;
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uint64_t total = 0;
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while (total < account_minreserve->second)
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{
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total += m_transfers[selected_transfers[sz]].amount();
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++sz;
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}
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selected_transfers.resize(sz);
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}
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// compute signature prefix hash
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std::string prefix_data = message;
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prefix_data.append((const char*)&m_account.get_keys().m_account_address, sizeof(cryptonote::account_public_address));
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for (size_t i = 0; i < selected_transfers.size(); ++i)
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{
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prefix_data.append((const char*)&m_transfers[selected_transfers[i]].m_key_image, sizeof(crypto::key_image));
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}
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crypto::hash prefix_hash;
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crypto::cn_fast_hash(prefix_data.data(), prefix_data.size(), prefix_hash);
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// generate proof entries
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std::vector<reserve_proof_entry> proofs(selected_transfers.size());
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std::unordered_set<cryptonote::subaddress_index> subaddr_indices = { {0,0} };
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for (size_t i = 0; i < selected_transfers.size(); ++i)
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{
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const transfer_details &td = m_transfers[selected_transfers[i]];
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reserve_proof_entry& proof = proofs[i];
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proof.txid = td.m_txid;
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proof.index_in_tx = td.m_internal_output_index;
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proof.key_image = td.m_key_image;
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subaddr_indices.insert(td.m_subaddr_index);
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// get tx pub key
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const crypto::public_key tx_pub_key = get_tx_pub_key_from_extra(td.m_tx, td.m_pk_index);
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THROW_WALLET_EXCEPTION_IF(tx_pub_key == crypto::null_pkey, error::wallet_internal_error, "The tx public key isn't found");
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const std::vector<crypto::public_key> additional_tx_pub_keys = get_additional_tx_pub_keys_from_extra(td.m_tx);
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// determine which tx pub key was used for deriving the output key
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const crypto::public_key *tx_pub_key_used = &tx_pub_key;
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for (int i = 0; i < 2; ++i)
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{
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proof.shared_secret = rct::rct2pk(rct::scalarmultKey(rct::pk2rct(*tx_pub_key_used), rct::sk2rct(m_account.get_keys().m_view_secret_key)));
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crypto::key_derivation derivation;
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THROW_WALLET_EXCEPTION_IF(!crypto::generate_key_derivation(proof.shared_secret, rct::rct2sk(rct::I), derivation),
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error::wallet_internal_error, "Failed to generate key derivation");
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crypto::public_key subaddress_spendkey;
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THROW_WALLET_EXCEPTION_IF(!derive_subaddress_public_key(td.get_public_key(), derivation, proof.index_in_tx, subaddress_spendkey),
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error::wallet_internal_error, "Failed to derive subaddress public key");
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if (m_subaddresses.count(subaddress_spendkey) == 1)
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break;
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THROW_WALLET_EXCEPTION_IF(additional_tx_pub_keys.empty(), error::wallet_internal_error,
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"Normal tx pub key doesn't derive the expected output, while the additional tx pub keys are empty");
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THROW_WALLET_EXCEPTION_IF(i == 1, error::wallet_internal_error,
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"Neither normal tx pub key nor additional tx pub key derive the expected output key");
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tx_pub_key_used = &additional_tx_pub_keys[proof.index_in_tx];
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}
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// generate signature for shared secret
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crypto::generate_tx_proof(prefix_hash, m_account.get_keys().m_account_address.m_view_public_key, *tx_pub_key_used, boost::none, proof.shared_secret, m_account.get_keys().m_view_secret_key, proof.shared_secret_sig);
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// derive ephemeral secret key
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crypto::key_image ki;
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cryptonote::keypair ephemeral;
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const bool r = cryptonote::generate_key_image_helper(m_account.get_keys(), m_subaddresses, td.get_public_key(), tx_pub_key, additional_tx_pub_keys, td.m_internal_output_index, ephemeral, ki);
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THROW_WALLET_EXCEPTION_IF(!r, error::wallet_internal_error, "Failed to generate key image");
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THROW_WALLET_EXCEPTION_IF(ephemeral.pub != td.get_public_key(), error::wallet_internal_error, "Derived public key doesn't agree with the stored one");
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// generate signature for key image
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const std::vector<const crypto::public_key*> pubs = { &ephemeral.pub };
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crypto::generate_ring_signature(prefix_hash, td.m_key_image, &pubs[0], 1, ephemeral.sec, 0, &proof.key_image_sig);
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}
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// collect all subaddress spend keys that received those outputs and generate their signatures
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std::unordered_map<crypto::public_key, crypto::signature> subaddr_spendkeys;
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for (const cryptonote::subaddress_index &index : subaddr_indices)
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{
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crypto::secret_key subaddr_spend_skey = m_account.get_keys().m_spend_secret_key;
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if (!index.is_zero())
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{
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crypto::secret_key m = cryptonote::get_subaddress_secret_key(m_account.get_keys().m_view_secret_key, index);
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crypto::secret_key tmp = subaddr_spend_skey;
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sc_add((unsigned char*)&subaddr_spend_skey, (unsigned char*)&m, (unsigned char*)&tmp);
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}
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crypto::public_key subaddr_spend_pkey;
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secret_key_to_public_key(subaddr_spend_skey, subaddr_spend_pkey);
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crypto::generate_signature(prefix_hash, subaddr_spend_pkey, subaddr_spend_skey, subaddr_spendkeys[subaddr_spend_pkey]);
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}
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// serialize & encode
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std::ostringstream oss;
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boost::archive::portable_binary_oarchive ar(oss);
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ar << proofs << subaddr_spendkeys;
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return "ReserveProofV1" + tools::base58::encode(oss.str());
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}
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bool wallet2::check_reserve_proof(const cryptonote::account_public_address &address, const std::string &message, const std::string &sig_str, uint64_t &total, uint64_t &spent)
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{
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uint32_t rpc_version;
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THROW_WALLET_EXCEPTION_IF(!check_connection(&rpc_version), error::wallet_internal_error, "Failed to connect to daemon: " + get_daemon_address());
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THROW_WALLET_EXCEPTION_IF(rpc_version < MAKE_CORE_RPC_VERSION(1, 0), error::wallet_internal_error, "Daemon RPC version is too old");
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static constexpr char header[] = "ReserveProofV1";
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THROW_WALLET_EXCEPTION_IF(!boost::string_ref{sig_str}.starts_with(header), error::wallet_internal_error,
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"Signature header check error");
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std::string sig_decoded;
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THROW_WALLET_EXCEPTION_IF(!tools::base58::decode(sig_str.substr(std::strlen(header)), sig_decoded), error::wallet_internal_error,
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"Signature decoding error");
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std::istringstream iss(sig_decoded);
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boost::archive::portable_binary_iarchive ar(iss);
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std::vector<reserve_proof_entry> proofs;
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std::unordered_map<crypto::public_key, crypto::signature> subaddr_spendkeys;
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ar >> proofs >> subaddr_spendkeys;
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THROW_WALLET_EXCEPTION_IF(subaddr_spendkeys.count(address.m_spend_public_key) == 0, error::wallet_internal_error,
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"The given address isn't found in the proof");
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// compute signature prefix hash
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std::string prefix_data = message;
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prefix_data.append((const char*)&address, sizeof(cryptonote::account_public_address));
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for (size_t i = 0; i < proofs.size(); ++i)
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{
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prefix_data.append((const char*)&proofs[i].key_image, sizeof(crypto::key_image));
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}
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crypto::hash prefix_hash;
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crypto::cn_fast_hash(prefix_data.data(), prefix_data.size(), prefix_hash);
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// fetch txes from daemon
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COMMAND_RPC_GET_TRANSACTIONS::request gettx_req;
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COMMAND_RPC_GET_TRANSACTIONS::response gettx_res;
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for (size_t i = 0; i < proofs.size(); ++i)
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gettx_req.txs_hashes.push_back(epee::string_tools::pod_to_hex(proofs[i].txid));
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m_daemon_rpc_mutex.lock();
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bool ok = net_utils::invoke_http_json("/gettransactions", gettx_req, gettx_res, m_http_client);
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m_daemon_rpc_mutex.unlock();
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THROW_WALLET_EXCEPTION_IF(!ok || gettx_res.txs.size() != proofs.size(),
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error::wallet_internal_error, "Failed to get transaction from daemon");
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// check spent status
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COMMAND_RPC_IS_KEY_IMAGE_SPENT::request kispent_req;
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COMMAND_RPC_IS_KEY_IMAGE_SPENT::response kispent_res;
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for (size_t i = 0; i < proofs.size(); ++i)
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kispent_req.key_images.push_back(epee::string_tools::pod_to_hex(proofs[i].key_image));
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m_daemon_rpc_mutex.lock();
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ok = epee::net_utils::invoke_http_json("/is_key_image_spent", kispent_req, kispent_res, m_http_client, rpc_timeout);
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m_daemon_rpc_mutex.unlock();
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THROW_WALLET_EXCEPTION_IF(!ok || kispent_res.spent_status.size() != proofs.size(),
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error::wallet_internal_error, "Failed to get key image spent status from daemon");
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total = spent = 0;
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for (size_t i = 0; i < proofs.size(); ++i)
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{
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const reserve_proof_entry& proof = proofs[i];
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THROW_WALLET_EXCEPTION_IF(gettx_res.txs[i].in_pool, error::wallet_internal_error, "Tx is unconfirmed");
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cryptonote::blobdata tx_data;
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ok = string_tools::parse_hexstr_to_binbuff(gettx_res.txs[i].as_hex, tx_data);
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THROW_WALLET_EXCEPTION_IF(!ok, error::wallet_internal_error, "Failed to parse transaction from daemon");
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crypto::hash tx_hash, tx_prefix_hash;
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cryptonote::transaction tx;
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THROW_WALLET_EXCEPTION_IF(!cryptonote::parse_and_validate_tx_from_blob(tx_data, tx, tx_hash, tx_prefix_hash), error::wallet_internal_error,
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"Failed to validate transaction from daemon");
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THROW_WALLET_EXCEPTION_IF(tx_hash != proof.txid, error::wallet_internal_error, "Failed to get the right transaction from daemon");
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THROW_WALLET_EXCEPTION_IF(proof.index_in_tx >= tx.vout.size(), error::wallet_internal_error, "index_in_tx is out of bound");
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const cryptonote::txout_to_key* const out_key = boost::get<cryptonote::txout_to_key>(std::addressof(tx.vout[proof.index_in_tx].target));
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THROW_WALLET_EXCEPTION_IF(!out_key, error::wallet_internal_error, "Output key wasn't found")
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// get tx pub key
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const crypto::public_key tx_pub_key = get_tx_pub_key_from_extra(tx);
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THROW_WALLET_EXCEPTION_IF(tx_pub_key == crypto::null_pkey, error::wallet_internal_error, "The tx public key isn't found");
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const std::vector<crypto::public_key> additional_tx_pub_keys = get_additional_tx_pub_keys_from_extra(tx);
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// check singature for shared secret
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ok = crypto::check_tx_proof(prefix_hash, address.m_view_public_key, tx_pub_key, boost::none, proof.shared_secret, proof.shared_secret_sig);
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if (!ok && additional_tx_pub_keys.size() == tx.vout.size())
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ok = crypto::check_tx_proof(prefix_hash, address.m_view_public_key, additional_tx_pub_keys[proof.index_in_tx], boost::none, proof.shared_secret, proof.shared_secret_sig);
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if (!ok)
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return false;
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// check signature for key image
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const std::vector<const crypto::public_key*> pubs = { &out_key->key };
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ok = crypto::check_ring_signature(prefix_hash, proof.key_image, &pubs[0], 1, &proof.key_image_sig);
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if (!ok)
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return false;
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// check if the address really received the fund
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crypto::key_derivation derivation;
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THROW_WALLET_EXCEPTION_IF(!crypto::generate_key_derivation(proof.shared_secret, rct::rct2sk(rct::I), derivation), error::wallet_internal_error, "Failed to generate key derivation");
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crypto::public_key subaddr_spendkey;
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crypto::derive_subaddress_public_key(out_key->key, derivation, proof.index_in_tx, subaddr_spendkey);
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THROW_WALLET_EXCEPTION_IF(subaddr_spendkeys.count(subaddr_spendkey) == 0, error::wallet_internal_error,
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"The address doesn't seem to have received the fund");
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// check amount
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uint64_t amount = tx.vout[proof.index_in_tx].amount;
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if (amount == 0)
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{
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// decode rct
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crypto::secret_key shared_secret;
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crypto::derivation_to_scalar(derivation, proof.index_in_tx, shared_secret);
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rct::ecdhTuple ecdh_info = tx.rct_signatures.ecdhInfo[proof.index_in_tx];
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rct::ecdhDecode(ecdh_info, rct::sk2rct(shared_secret));
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amount = rct::h2d(ecdh_info.amount);
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}
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total += amount;
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if (kispent_res.spent_status[i])
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spent += amount;
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}
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// check signatures for all subaddress spend keys
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for (const auto &i : subaddr_spendkeys)
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{
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if (!crypto::check_signature(prefix_hash, i.first, i.second))
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return false;
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}
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return true;
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}
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std::string wallet2::get_wallet_file() const
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{
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return m_wallet_file;
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