wallet: auto sync outputs and key images in cold signing files

When passing around unsigned and signed transactions, outputs
and key images are passed along (outputs are passed along unsigned
transactions from the hot wallet to the cold wallet, key images
are passed along with signed transations from the cold wallet
to the hot wallet), to allow more user friendly syncing between
hot and cold wallets.

src/simplewallet/simplewallet.cpp

@@ -1777,7 +1777,7 @@ bool simple_wallet::show_incoming_transfers(const std::vector<std::string>& args
       }
       std::string verbose_string;
       if (verbose)
-        verbose_string = (boost::format("%68s%68s") % td.get_public_key() % td.m_key_image).str();
+        verbose_string = (boost::format("%68s%68s") % td.get_public_key() % (td.m_key_image_known ? epee::string_tools::pod_to_hex(td.m_key_image) : std::string('?', 64))).str();
       message_writer(td.m_spent ? epee::log_space::console_color_magenta : epee::log_space::console_color_green, false) <<
         boost::format("%21s%8s%12s%8s%16u%68s%s") %
         print_money(td.amount()) %
@@ -2774,7 +2774,7 @@ bool simple_wallet::sweep_all(const std::vector<std::string> &args_)
   return true;
 }
 //----------------------------------------------------------------------------------------------------
-bool simple_wallet::accept_loaded_tx(const std::function<size_t()> get_num_txes, const std::function<const tools::wallet2::tx_construction_data&(size_t)> &get_tx)
+bool simple_wallet::accept_loaded_tx(const std::function<size_t()> get_num_txes, const std::function<const tools::wallet2::tx_construction_data&(size_t)> &get_tx, const std::string &extra_message)
 {
   // gather info to ask the user
   uint64_t amount = 0, amount_to_dests = 0, change = 0;
@@ -2847,19 +2847,25 @@ bool simple_wallet::accept_loaded_tx(const std::function<size_t()> get_num_txes,
     change_string += tr("no change");
 
   uint64_t fee = amount - amount_to_dests;
-  std::string prompt_str = (boost::format(tr("Loaded %lu transactions, for %s, fee %s, %s, %s, with min mixin %lu. Is this okay? (Y/Yes/N/No)")) % (unsigned long)get_num_txes() % print_money(amount) % print_money(fee) % dest_string % change_string % (unsigned long)min_mixin).str();
+  std::string prompt_str = (boost::format(tr("Loaded %lu transactions, for %s, fee %s, %s, %s, with min mixin %lu. %sIs this okay? (Y/Yes/N/No)")) % (unsigned long)get_num_txes() % print_money(amount) % print_money(fee) % dest_string % change_string % (unsigned long)min_mixin % extra_message).str();
   std::string accepted = command_line::input_line(prompt_str);
   return is_it_true(accepted);
 }
 //----------------------------------------------------------------------------------------------------
 bool simple_wallet::accept_loaded_tx(const tools::wallet2::unsigned_tx_set &txs)
 {
-  return accept_loaded_tx([&txs](){return txs.txes.size();}, [&txs](size_t n)->const tools::wallet2::tx_construction_data&{return txs.txes[n];});
+  std::string extra_message;
+  if (!txs.transfers.empty())
+    extra_message = (boost::format("%u outputs to import. ") % (unsigned)txs.transfers.size()).str();
+  return accept_loaded_tx([&txs](){return txs.txes.size();}, [&txs](size_t n)->const tools::wallet2::tx_construction_data&{return txs.txes[n];}, extra_message);
 }
 //----------------------------------------------------------------------------------------------------
 bool simple_wallet::accept_loaded_tx(const tools::wallet2::signed_tx_set &txs)
 {
-  return accept_loaded_tx([&txs](){return txs.ptx.size();}, [&txs](size_t n)->const tools::wallet2::tx_construction_data&{return txs.ptx[n].construction_data;});
+  std::string extra_message;
+  if (!txs.key_images.empty())
+    extra_message = (boost::format("%u key images to import. ") % (unsigned)txs.key_images.size()).str();
+  return accept_loaded_tx([&txs](){return txs.ptx.size();}, [&txs](size_t n)->const tools::wallet2::tx_construction_data&{return txs.ptx[n].construction_data;}, extra_message);
 }
 //----------------------------------------------------------------------------------------------------
 bool simple_wallet::sign_transfer(const std::vector<std::string> &args_)
@@ -2870,9 +2876,10 @@ bool simple_wallet::sign_transfer(const std::vector<std::string> &args_)
      return true;
   }
 
+  std::vector<tools::wallet2::pending_tx> ptx;
   try
   {
-    bool r = m_wallet->sign_tx("unsigned_monero_tx", "signed_monero_tx", [&](const tools::wallet2::unsigned_tx_set &tx){ return accept_loaded_tx(tx); });
+    bool r = m_wallet->sign_tx("unsigned_monero_tx", "signed_monero_tx", ptx, [&](const tools::wallet2::unsigned_tx_set &tx){ return accept_loaded_tx(tx); });
     if (!r)
     {
       fail_msg_writer() << tr("Failed to sign transaction");
@@ -2885,7 +2892,14 @@ bool simple_wallet::sign_transfer(const std::vector<std::string> &args_)
     return true;
   }
 
-  success_msg_writer(true) << tr("Transaction successfully signed to file: ") << "signed_monero_tx";
+  std::string txids_as_text;
+  for (const auto &t: ptx)
+  {
+    if (!txids_as_text.empty())
+      txids_as_text += (", ");
+    txids_as_text += epee::string_tools::pod_to_hex(get_transaction_hash(t.tx));
+  }
+  success_msg_writer(true) << tr("Transaction successfully signed to file ") << "signed_monero_tx" << ", txid " << txids_as_text;
   return true;
 }
 //----------------------------------------------------------------------------------------------------

src/simplewallet/simplewallet.h

@@ -155,7 +155,7 @@ namespace cryptonote
     uint64_t get_daemon_blockchain_height(std::string& err);
     bool try_connect_to_daemon(bool silent = false);
     bool ask_wallet_create_if_needed();
-    bool accept_loaded_tx(const std::function<size_t()> get_num_txes, const std::function<const tools::wallet2::tx_construction_data&(size_t)> &get_tx);
+    bool accept_loaded_tx(const std::function<size_t()> get_num_txes, const std::function<const tools::wallet2::tx_construction_data&(size_t)> &get_tx, const std::string &extra_message = std::string());
     bool accept_loaded_tx(const tools::wallet2::unsigned_tx_set &txs);
     bool accept_loaded_tx(const tools::wallet2::signed_tx_set &txs);
     bool get_address_from_str(const std::string &str, cryptonote::account_public_address &address, bool &has_payment_id, crypto::hash8 &payment_id);

src/wallet/wallet2.cpp

@@ -2953,6 +2953,7 @@ bool wallet2::save_tx(const std::vector<pending_tx>& ptx_vector, const std::stri
   unsigned_tx_set txs;
   for (auto &tx: ptx_vector)
     txs.txes.push_back(tx.construction_data);
+  txs.transfers = m_transfers;
   std::string s = obj_to_json_str(txs);
   if (s.empty())
     return false;
@@ -2963,7 +2964,7 @@ bool wallet2::save_tx(const std::vector<pending_tx>& ptx_vector, const std::stri
   return epee::file_io_utils::save_string_to_file(filename, std::string(UNSIGNED_TX_PREFIX) + s);
 }
 //----------------------------------------------------------------------------------------------------
-bool wallet2::sign_tx(const std::string &unsigned_filename, const std::string &signed_filename, std::function<bool(const unsigned_tx_set&)> accept_func)
+bool wallet2::sign_tx(const std::string &unsigned_filename, const std::string &signed_filename, std::vector<wallet2::pending_tx> &txs, std::function<bool(const unsigned_tx_set&)> accept_func)
 {
   std::string s;
   boost::system::error_code errcode;
@@ -2998,6 +2999,8 @@ bool wallet2::sign_tx(const std::string &unsigned_filename, const std::string &s
     return false;
   }
 
+  import_outputs(exported_txs.transfers);
+
   // sign the transactions
   signed_tx_set signed_txes;
   for (size_t n = 0; n < exported_txs.txes.size(); ++n)
@@ -3043,6 +3046,17 @@ bool wallet2::sign_tx(const std::string &unsigned_filename, const std::string &s
     ptx.tx_key = rct::rct2sk(rct::identity()); // don't send it back to the untrusted view wallet
     ptx.dests = sd.splitted_dsts;
     ptx.construction_data = sd;
+
+    txs.push_back(ptx);
+  }
+
+  // add key images
+  signed_txes.key_images.resize(m_transfers.size());
+  for (size_t i = 0; i < m_transfers.size(); ++i)
+  {
+    if (!m_transfers[i].m_key_image_known)
+      LOG_PRINT_L0("WARNING: key image not known in signing wallet at index " << i);
+    signed_txes.key_images[i] = m_transfers[i].m_key_image;
   }
 
   s = obj_to_json_str(signed_txes);
@@ -3092,6 +3106,23 @@ bool wallet2::load_tx(const std::string &signed_filename, std::vector<tools::wal
     return false;
   }
 
+  // import key images
+  if (signed_txs.key_images.size() > m_transfers.size())
+  {
+    LOG_PRINT_L1("More key images returned that we know outputs for");
+    return false;
+  }
+  for (size_t i = 0; i < signed_txs.key_images.size(); ++i)
+  {
+    transfer_details &td = m_transfers[i];
+    if (td.m_key_image_known && td.m_key_image != signed_txs.key_images[i])
+      LOG_PRINT_L0("WARNING: imported key image differs from previously known key image at index " << i << ": trusting imported one");
+    td.m_key_image = signed_txs.key_images[i];
+    m_key_images[m_transfers[i].m_key_image] = i;
+    td.m_key_image_known = true;
+    m_pub_keys[m_transfers[i].get_public_key()] = i;
+  }
+
   ptx = signed_txs.ptx;
 
   return true;

src/wallet/wallet2.h

@@ -133,6 +133,21 @@ namespace tools
       bool is_rct() const { return m_rct; }
       uint64_t amount() const { return m_amount; }
       const crypto::public_key &get_public_key() const { return boost::get<const cryptonote::txout_to_key>(m_tx.vout[m_internal_output_index].target).key; }
+
+      BEGIN_SERIALIZE_OBJECT()
+        FIELD(m_block_height)
+        FIELD(m_tx)
+        FIELD(m_txid)
+        FIELD(m_internal_output_index)
+        FIELD(m_global_output_index)
+        FIELD(m_spent)
+        FIELD(m_spent_height)
+        FIELD(m_key_image)
+        FIELD(m_mask)
+        FIELD(m_amount)
+        FIELD(m_rct)
+        FIELD(m_key_image_known)
+      END_SERIALIZE()
     };
 
     struct payment_details
@@ -226,16 +241,20 @@ namespace tools
     struct unsigned_tx_set
     {
       std::vector<tx_construction_data> txes;
+      wallet2::transfer_container transfers;
       BEGIN_SERIALIZE_OBJECT()
         FIELD(txes)
+        FIELD(transfers)
       END_SERIALIZE()
     };
 
     struct signed_tx_set
     {
       std::vector<pending_tx> ptx;
+      std::vector<crypto::key_image> key_images;
       BEGIN_SERIALIZE_OBJECT()
         FIELD(ptx)
+        FIELD(key_images)
       END_SERIALIZE()
     };
 
@@ -377,7 +396,7 @@ namespace tools
     void commit_tx(pending_tx& ptx_vector);
     void commit_tx(std::vector<pending_tx>& ptx_vector);
     bool save_tx(const std::vector<pending_tx>& ptx_vector, const std::string &filename);
-    bool sign_tx(const std::string &unsigned_filename, const std::string &signed_filename, std::function<bool(const unsigned_tx_set&)> accept_func = NULL);
+    bool sign_tx(const std::string &unsigned_filename, const std::string &signed_filename, std::vector<wallet2::pending_tx> &ptx, std::function<bool(const unsigned_tx_set&)> accept_func = NULL);
     bool load_tx(const std::string &signed_filename, std::vector<tools::wallet2::pending_tx> &ptx, std::function<bool(const signed_tx_set&)> accept_func = NULL);
     std::vector<pending_tx> create_transactions(std::vector<cryptonote::tx_destination_entry> dsts, const size_t fake_outs_count, const uint64_t unlock_time, uint32_t priority, const std::vector<uint8_t> extra, bool trusted_daemon);
     std::vector<wallet2::pending_tx> create_transactions_2(std::vector<cryptonote::tx_destination_entry> dsts, const size_t fake_outs_count, const uint64_t unlock_time, uint32_t priority, const std::vector<uint8_t> extra, bool trusted_daemon);