diff --git a/src/simplewallet/simplewallet.cpp b/src/simplewallet/simplewallet.cpp
index 137d84b6e..d2acf5182 100755
--- a/src/simplewallet/simplewallet.cpp
+++ b/src/simplewallet/simplewallet.cpp
@@ -64,6 +64,7 @@
 #include "wallet/wallet_args.h"
 #include "version.h"
 #include <stdexcept>
+#include "wallet/message_store.h"
 
 #ifdef WIN32
 #include <boost/locale.hpp>
@@ -787,6 +788,8 @@ bool simple_wallet::print_fee_info(const std::vector<std::string> &args/* = std:
 
 bool simple_wallet::prepare_multisig(const std::vector<std::string> &args)
 {
+  m_command_successful = false;
+  bool by_mms = called_by_mms();
   if (m_wallet->key_on_device())
   {
     fail_msg_writer() << tr("command not supported by HW wallet");
@@ -820,11 +823,20 @@ bool simple_wallet::prepare_multisig(const std::vector<std::string> &args)
   success_msg_writer() << multisig_info;
   success_msg_writer() << tr("Send this multisig info to all other participants, then use make_multisig <threshold> <info1> [<info2>...] with others' multisig info");
   success_msg_writer() << tr("This includes the PRIVATE view key, so needs to be disclosed only to that multisig wallet's participants ");
+
+  if (by_mms)
+  {
+    get_message_store().process_wallet_created_data(get_multisig_wallet_state(), mms::message_type::key_set, multisig_info);
+  }
+
+  m_command_successful = true;
   return true;
 }
 
 bool simple_wallet::make_multisig(const std::vector<std::string> &args)
 {
+  m_command_successful = false;
+  bool by_mms = called_by_mms();
   if (m_wallet->key_on_device())
   {
     fail_msg_writer() << tr("command not supported by HW wallet");
@@ -880,6 +892,11 @@ bool simple_wallet::make_multisig(const std::vector<std::string> &args)
       success_msg_writer() << tr("Another step is needed");
       success_msg_writer() << multisig_extra_info;
       success_msg_writer() << tr("Send this multisig info to all other participants, then use finalize_multisig <info1> [<info2>...] with others' multisig info");
+      if (by_mms)
+      {
+        get_message_store().process_wallet_created_data(get_multisig_wallet_state(), mms::message_type::finalizing_key_set, multisig_extra_info);
+      }
+      m_command_successful = true;
       return true;
     }
   }
@@ -898,11 +915,14 @@ bool simple_wallet::make_multisig(const std::vector<std::string> &args)
   success_msg_writer() << std::to_string(threshold) << "/" << total << tr(" multisig address: ")
       << m_wallet->get_account().get_public_address_str(m_wallet->nettype());
 
+  m_command_successful = true;
   return true;
 }
 
 bool simple_wallet::finalize_multisig(const std::vector<std::string> &args)
 {
+  m_command_successful = false;
+  bool by_mms = called_by_mms();
   bool ready;
   if (m_wallet->key_on_device())
   {
@@ -947,11 +967,14 @@ bool simple_wallet::finalize_multisig(const std::vector<std::string> &args)
     return true;
   }
 
+  m_command_successful = true;
   return true;
 }
 
 bool simple_wallet::export_multisig(const std::vector<std::string> &args)
 {
+  m_command_successful = false;
+  bool by_mms = called_by_mms();
   bool ready;
   if (m_wallet->key_on_device())
   {
@@ -977,17 +1000,24 @@ bool simple_wallet::export_multisig(const std::vector<std::string> &args)
     return true;
 
   const std::string filename = args[0];
-  if (m_wallet->confirm_export_overwrite() && !check_file_overwrite(filename))
+  if (!by_mms && m_wallet->confirm_export_overwrite() && !check_file_overwrite(filename))
     return true;
   try
   {
     cryptonote::blobdata ciphertext = m_wallet->export_multisig();
 
-    bool r = epee::file_io_utils::save_string_to_file(filename, ciphertext);
-    if (!r)
+    if (by_mms)
     {
-      fail_msg_writer() << tr("failed to save file ") << filename;
-      return true;
+      get_message_store().process_wallet_created_data(get_multisig_wallet_state(), mms::message_type::multisig_sync_data, ciphertext);
+    }
+    else
+    {
+      bool r = epee::file_io_utils::save_string_to_file(filename, ciphertext);
+      if (!r)
+      {
+	fail_msg_writer() << tr("failed to save file ") << filename;
+	return true;
+      }
     }
   }
   catch (const std::exception &e)
@@ -998,11 +1028,14 @@ bool simple_wallet::export_multisig(const std::vector<std::string> &args)
   }
 
   success_msg_writer() << tr("Multisig info exported to ") << filename;
+  m_command_successful = true;
   return true;
 }
 
 bool simple_wallet::import_multisig(const std::vector<std::string> &args)
 {
+  m_command_successful = false;
+  bool by_mms = called_by_mms();
   bool ready;
   uint32_t threshold, total;
   if (m_wallet->key_on_device())
@@ -1031,15 +1064,22 @@ bool simple_wallet::import_multisig(const std::vector<std::string> &args)
   std::vector<cryptonote::blobdata> info;
   for (size_t n = 0; n < args.size(); ++n)
   {
-    const std::string filename = args[n];
-    std::string data;
-    bool r = epee::file_io_utils::load_file_to_string(filename, data);
-    if (!r)
+    if (by_mms)
     {
-      fail_msg_writer() << tr("failed to read file ") << filename;
-      return true;
+      info.push_back(args[n]);
+    }
+    else
+    {
+      const std::string &filename = args[n];
+      std::string data;
+      bool r = epee::file_io_utils::load_file_to_string(filename, data);
+      if (!r)
+      {
+	fail_msg_writer() << tr("failed to read file ") << filename;
+	return true;
+      }
+      info.push_back(std::move(data));
     }
-    info.push_back(std::move(data));
   }
 
   LOCK_IDLE_SCOPE();
@@ -1051,6 +1091,7 @@ bool simple_wallet::import_multisig(const std::vector<std::string> &args)
     // Clear line "Height xxx of xxx"
     std::cout << "\r                                                                \r";
     success_msg_writer() << tr("Multisig info imported");
+    m_command_successful = true;
   }
   catch (const std::exception &e)
   {
@@ -1083,6 +1124,8 @@ bool simple_wallet::accept_loaded_tx(const tools::wallet2::multisig_tx_set &txs)
 
 bool simple_wallet::sign_multisig(const std::vector<std::string> &args)
 {
+  m_command_successful = false;
+  bool by_mms = called_by_mms();
   bool ready;
   if (m_wallet->key_on_device())
   {
@@ -1111,11 +1154,48 @@ bool simple_wallet::sign_multisig(const std::vector<std::string> &args)
   uint32_t signers = 0;
   try
   {
-    bool r = m_wallet->sign_multisig_tx_from_file(filename, txids, [&](const tools::wallet2::multisig_tx_set &tx){ signers = tx.m_signers.size(); return accept_loaded_tx(tx); });
-    if (!r)
+    if (by_mms)
     {
-      fail_msg_writer() << tr("Failed to sign multisig transaction");
-      return true;
+      tools::wallet2::multisig_tx_set exported_txs;
+      std::string ciphertext;
+      bool r = m_wallet->load_multisig_tx(args[0], exported_txs, [&](const tools::wallet2::multisig_tx_set &tx){ signers = tx.m_signers.size(); return accept_loaded_tx(tx); });
+      if (r)
+      {
+	r = m_wallet->sign_multisig_tx(exported_txs, txids);
+      }
+      if (r)
+      {
+	ciphertext = m_wallet->save_multisig_tx(exported_txs);
+        if (ciphertext.empty())
+	{
+	  r = false;
+	}
+      }
+      if (r)
+      {
+	mms::message_type message_type = mms::message_type::fully_signed_tx;
+	if (txids.empty())
+	{
+	  message_type = mms::message_type::partially_signed_tx;
+	}
+        get_message_store().process_wallet_created_data(get_multisig_wallet_state(), message_type, ciphertext);
+	filename = "MMS";   // for the messages below
+	m_command_successful = true;
+      }
+      else
+      {
+	fail_msg_writer() << tr("Failed to sign multisig transaction");
+	return true;
+      }
+    }
+    else
+    {
+      bool r = m_wallet->sign_multisig_tx_from_file(filename, txids, [&](const tools::wallet2::multisig_tx_set &tx){ signers = tx.m_signers.size(); return accept_loaded_tx(tx); });
+      if (!r)
+      {
+	fail_msg_writer() << tr("Failed to sign multisig transaction");
+	return true;
+      }
     }
   }
   catch (const tools::error::multisig_export_needed& e)
@@ -1155,6 +1235,8 @@ bool simple_wallet::sign_multisig(const std::vector<std::string> &args)
 
 bool simple_wallet::submit_multisig(const std::vector<std::string> &args)
 {
+  m_command_successful = false;
+  bool by_mms = called_by_mms();
   bool ready;
   uint32_t threshold;
   if (m_wallet->key_on_device())
@@ -1186,11 +1268,23 @@ bool simple_wallet::submit_multisig(const std::vector<std::string> &args)
   try
   {
     tools::wallet2::multisig_tx_set txs;
-    bool r = m_wallet->load_multisig_tx_from_file(filename, txs, [&](const tools::wallet2::multisig_tx_set &tx){ return accept_loaded_tx(tx); });
-    if (!r)
+    if (by_mms)
     {
-      fail_msg_writer() << tr("Failed to load multisig transaction from file");
-      return true;
+      bool r = m_wallet->load_multisig_tx(args[0], txs, [&](const tools::wallet2::multisig_tx_set &tx){ return accept_loaded_tx(tx); });
+      if (!r)
+      {
+        fail_msg_writer() << tr("Failed to load multisig transaction from MMS");
+	return true;
+      }
+    }
+    else
+    {
+      bool r = m_wallet->load_multisig_tx_from_file(filename, txs, [&](const tools::wallet2::multisig_tx_set &tx){ return accept_loaded_tx(tx); });
+      if (!r)
+      {
+	fail_msg_writer() << tr("Failed to load multisig transaction from file");
+	return true;
+      }
     }
     if (txs.m_signers.size() < threshold)
     {
@@ -1206,6 +1300,7 @@ bool simple_wallet::submit_multisig(const std::vector<std::string> &args)
       success_msg_writer(true) << tr("Transaction successfully submitted, transaction ") << get_transaction_hash(ptx.tx) << ENDL
           << tr("You can check its status by using the `show_transfers` command.");
     }
+    m_command_successful = true;
   }
   catch (const std::exception &e)
   {
@@ -1296,6 +1391,816 @@ bool simple_wallet::export_raw_multisig(const std::vector<std::string> &args)
   return true;
 }
 
+// MMS ---------------------------------------------------------------------------------------------------
+
+// Access to the message store, or more exactly to the list of the messages that can be changed
+// by the idle thread, is guarded by the same mutex-based mechanism as access to the wallet
+// as a whole and thus e.g. uses the "LOCK_IDLE_SCOPE" macro. This is a little over-cautious, but
+// simple and safe. Care has to be taken however where MMS methods call other simplewallet methods
+// that use "LOCK_IDLE_SCOPE" as this cannot be nested!
+
+// Methods for commands like "export_multisig_info" usually read data from file(s) or write data
+// to files. The MMS calls now those methods as well, to produce data for messages and to process data
+// from messages. As it would be quite inconvenient for the MMS to write data for such methods to files
+// first or get data out of result files after the call, those methods detect a call from the MMS and
+// expect data as arguments instead of files and give back data by calling 'process_wallet_created_data'.
+bool simple_wallet::called_by_mms()
+{
+  bool by_mms = m_called_by_mms;
+  m_called_by_mms = false;
+  return by_mms;
+}
+
+bool simple_wallet::user_confirms(const std::string &question)
+{
+   std::string answer = input_line(question + tr(" (Y/Yes/N/No): "));
+   return !std::cin.eof() && command_line::is_yes(answer);
+}
+
+bool simple_wallet::get_number_from_arg(const std::string &arg, uint32_t &number, const uint32_t lower_bound, const uint32_t upper_bound)
+{
+  bool valid = false;
+  try
+  {
+    number = boost::lexical_cast<uint32_t>(arg);
+    valid = (number >= lower_bound) && (number <= upper_bound);
+  }
+  catch(const boost::bad_lexical_cast &)
+  {
+  }
+  return valid;
+}
+
+bool simple_wallet::choose_mms_processing(const std::vector<mms::processing_data> &data_list, uint32_t &choice)
+{
+  uint32_t choices = data_list.size();
+  if (choices == 1)
+  {
+    choice = 0;
+    return true;
+  }
+  mms::message_store& ms = m_wallet->get_message_store();
+  success_msg_writer() << tr("Choose processing:");
+  std::string text;
+  for (size_t i = 0; i < choices; ++i)
+  {
+    const mms::processing_data &data = data_list[i];
+    text = std::to_string(i+1) + ": ";
+    switch (data.processing)
+    {
+    case mms::message_processing::sign_tx:
+      text += tr("Sign tx");
+      break;
+    case mms::message_processing::send_tx:
+    {
+      mms::message m;
+      ms.get_message_by_id(data.message_ids[0], m);
+      if (m.type == mms::message_type::fully_signed_tx)
+      {
+        text += tr("Send the tx for submission to ");
+      }
+      else
+      {
+        text += tr("Send the tx for signing to ");
+      }
+      mms::coalition_member member = ms.get_member(data.receiving_member_index);
+      text += ms.member_to_string(member, 50);
+      break;
+    }
+    case mms::message_processing::submit_tx:
+      text += tr("Submit tx");
+      break;
+    default:
+      text += tr("unknown");
+      break;
+    }
+    success_msg_writer() << text;
+  }
+
+  std::string line = input_line(tr("Choice: "));
+  if (std::cin.eof() || line.empty())
+  {
+    return false;
+  }
+  bool choice_ok = get_number_from_arg(line, choice, 1, choices);
+  if (choice_ok)
+  {
+    choice--;
+  }
+  else
+  {
+    fail_msg_writer() << tr("Wrong choice");
+  }
+  return choice_ok;
+}
+
+static std::string get_human_readable_timestamp(uint64_t ts);
+static std::string get_human_readable_timespan(std::chrono::seconds seconds);
+
+void simple_wallet::list_mms_messages(const std::vector<mms::message> &messages)
+{
+  success_msg_writer() << boost::format("%4s %-4s %-30s %-21s %7s %-15s %-40s") % tr("Id") % tr("I/O") % tr("Coalition Member")
+	  % tr("Message Type") % tr("Height") % tr("Message State") % tr("Since");
+  mms::message_store& ms = m_wallet->get_message_store();
+  uint64_t now = time(NULL);
+  for (size_t i = 0; i < messages.size(); ++i)
+  {
+    const mms::message &m = messages[i];
+    const mms::coalition_member &member = ms.get_member(m.member_index);
+    bool highlight = (m.state == mms::message_state::ready_to_send) || (m.state == mms::message_state::waiting);
+    message_writer(m.direction == mms::message_direction::out ? console_color_green : console_color_magenta, highlight) <<
+	    boost::format("%4s %-4s %-30s %-21s %7s %-15s %-40s") %
+	    m.id %
+	    ms.message_direction_to_string(m.direction) %
+	    ms.member_to_string(member, 30) %
+	    ms.message_type_to_string(m.type) %
+	    m.wallet_height %
+	    ms.message_state_to_string(m.state) %
+	    (get_human_readable_timestamp(m.modified) + ", " + get_human_readable_timespan(std::chrono::seconds(now - m.modified)) + tr(" ago"));
+  }
+}
+
+void simple_wallet::show_message(const mms::message &m)
+{
+  mms::message_store& ms = m_wallet->get_message_store();
+  const mms::coalition_member &member = ms.get_member(m.member_index);
+  bool display_content;
+  switch (m.type)
+  {
+  case mms::message_type::key_set:
+  case mms::message_type::finalizing_key_set:
+  case mms::message_type::note:
+    display_content = true;
+    break;
+  default:
+    display_content = false;
+  }
+  uint64_t now = time(NULL);
+  success_msg_writer() << "";
+  success_msg_writer() << tr("Message ") << m.id;
+  success_msg_writer() << tr("In/out: ") << ms.message_direction_to_string(m.direction);
+  success_msg_writer() << tr("Type: ") << ms.message_type_to_string(m.type);
+  success_msg_writer() << tr("State: ") << boost::format(tr("%s since %s, %s ago")) %
+	  ms.message_state_to_string(m.state) % get_human_readable_timestamp(m.modified) % get_human_readable_timespan(std::chrono::seconds(now - m.modified));
+  if (m.sent == 0)
+  {
+    success_msg_writer() << tr("Sent: Never");
+  }
+  else
+  {
+    success_msg_writer() << boost::format(tr("Sent: %s, %s ago")) %
+	    get_human_readable_timestamp(m.sent) % get_human_readable_timespan(std::chrono::seconds(now - m.sent));
+  }
+  success_msg_writer() << tr("Member: ") << ms.member_to_string(member, 100);
+  success_msg_writer() << tr("Content size: ") << m.content.length() << tr(" bytes");
+  success_msg_writer() << tr("Content: ") << (display_content ? m.content : tr("(binary data)"));
+
+  if (m.type == mms::message_type::note)
+  {
+    // Showing a note and read its text is "processing" it: Set the state accordingly
+    // which will also delete it from Bitmessage as a side effect
+    // (Without this little "twist" it would never change the state, and never get deleted)
+    ms.set_message_processed_or_sent(m.id);
+  }
+}
+
+void simple_wallet::ask_send_all_ready_messages()
+{
+  mms::message_store& ms = m_wallet->get_message_store();
+  std::vector<mms::message> ready_messages;
+  const std::vector<mms::message> &messages = ms.get_all_messages();
+  for (size_t i = 0; i < messages.size(); ++i)
+  {
+    const mms::message &m = messages[i];
+    if (m.state == mms::message_state::ready_to_send)
+    {
+      ready_messages.push_back(m);
+    }
+  }
+  if (ready_messages.size() != 0)
+  {
+    list_mms_messages(ready_messages);
+    bool send = ms.get_auto_send();
+    if (!send)
+    {
+      send = user_confirms(tr("Send these messages now?"));
+    }
+    if (send)
+    {
+      mms::multisig_wallet_state state = get_multisig_wallet_state();
+      for (size_t i = 0; i < ready_messages.size(); ++i)
+      {
+	ms.send_message(state, ready_messages[i].id);
+	ms.set_message_processed_or_sent(ready_messages[i].id);
+      }
+      success_msg_writer() << tr("Sent.");
+    }
+  }
+}
+
+bool simple_wallet::get_message_from_arg(const std::string &arg, mms::message &m)
+{
+  mms::message_store& ms = m_wallet->get_message_store();
+  bool valid_id = false;
+  uint32_t id;
+  try
+  {
+    id = (uint32_t)boost::lexical_cast<uint32_t>(arg);
+    valid_id = ms.get_message_by_id(id, m);
+  }
+  catch (const boost::bad_lexical_cast &)
+  {
+  }
+  if (!valid_id)
+  {
+    fail_msg_writer() << tr("Invalid message id");
+  }
+  return valid_id;
+}
+
+void simple_wallet::mms_init(const std::vector<std::string> &args)
+{
+  // mms init <threshold>/<coalition_size> <own_label> <own_transport_address>
+  // Example: mms init 2/3 rbrunner BM-2cUVEbbb3H6ojddYQziK3RafJ5GPcFQv7e
+  // For now, assume we still have the original Monero address available, before "make_multisig"
+  if (args.size() != 4)
+  {
+    fail_msg_writer() << tr("usage: mms init <threshold>/<coalition_size> <own_label> <own_transport_address>");
+    return;
+  }
+  mms::message_store& ms = m_wallet->get_message_store();
+  if (ms.get_active())
+  {
+    if (!user_confirms(tr("The MMS is already initialized. Re-initialize by deleting all member info and messages?")))
+    {
+      return;
+    }
+  }
+  uint32_t threshold;
+  uint32_t coalition_size;
+  const std::string &mn = args[1];
+  std::vector<std::string> numbers;
+  boost::split(numbers, mn, boost::is_any_of("/"));
+  bool mn_ok = (numbers.size() == 2)
+               && get_number_from_arg(numbers[0], threshold, 1, 100)
+               && get_number_from_arg(numbers[1], coalition_size, 2, 100);
+  if (mn_ok)
+  {
+    mn_ok = (threshold == coalition_size) || (threshold == (coalition_size -1));
+    // Fully general cases like 3/5 not yet supported
+  }
+  if (!mn_ok)
+  {
+    fail_msg_writer() << tr("Error in threshold and/or coalition size");
+    return;
+  }
+  ms.init(get_multisig_wallet_state(), args[2], args[3], coalition_size, threshold);
+}
+
+void simple_wallet::mms_info(const std::vector<std::string> &args)
+{
+  mms::message_store& ms = m_wallet->get_message_store();
+  success_msg_writer() << boost::format("The MMS is active for %s/%s multisig.")
+	  % ms.get_threshold() % ms.get_coalition_size();
+}
+
+void simple_wallet::mms_member(const std::vector<std::string> &args)
+// mms 0:member [1:<number> <2:label> [3:<transport_address> [4:<wownero_address>]]]
+{
+  mms::message_store& ms = m_wallet->get_message_store();
+  const std::vector<mms::coalition_member> &members = ms.get_all_members();
+  if (args.size() == 1)
+  {
+    // Without further parameters list all defined members
+    success_msg_writer() << boost::format("%2s %-20s %-s") % tr("#") % tr("Label") % tr("Transport Address");
+    success_msg_writer() << boost::format("%2s %-20s %-s") % "" % "" % tr("Wownero Address");
+    for (size_t i = 0; i < members.size(); ++i)
+    {
+      const mms::coalition_member &member = members[i];
+      std::string label = member.label.empty() ? tr("<not set>") : member.label;
+      std::string monero_address;
+      if (member.monero_address_known)
+      {
+	monero_address = get_account_address_as_str(m_wallet->nettype(), false, member.monero_address);
+      }
+      else
+      {
+	monero_address = tr("<not set>");
+      }
+      std::string transport_address = member.transport_address.empty() ? tr("<not set>") : member.transport_address;
+      success_msg_writer() << boost::format("%2s %-20s %-s") % (i + 1) % label % transport_address;
+      success_msg_writer() << boost::format("%2s %-20s %-s") % "" % "" % monero_address;
+      success_msg_writer() << "";
+    }
+    return;
+  }
+
+  uint32_t index;
+  bool index_valid = get_number_from_arg(args[1], index, 1, ms.get_coalition_size());
+  if (index_valid)
+  {
+    index--;
+  }
+  else
+  {
+    fail_msg_writer() << tr("Invalid coalition member number ") + args[1];
+    return;
+  }
+  if (args.size() < 3)
+  {
+    fail_msg_writer() << tr("mms member [<number> <label> [<transport_address> [<wownero_address>]]]");
+    return;
+  }
+
+  boost::optional<string> label = args[2];
+  boost::optional<string> transport_address;
+  if (args.size() >= 4)
+  {
+    transport_address = args[3];
+  }
+  boost::optional<cryptonote::account_public_address> monero_address;
+  mms::multisig_wallet_state state = get_multisig_wallet_state();
+  if (args.size() >= 5)
+  {
+    cryptonote::address_parse_info info;
+    bool ok = cryptonote::get_account_address_from_str_or_url(info, m_wallet->nettype(), args[4], oa_prompter);
+    if (!ok)
+    {
+      fail_msg_writer() << tr("Invalid Wownero address");
+      return;
+    }
+    monero_address = info.address;
+    const std::vector<mms::message> &messages = ms.get_all_messages();
+    if ((messages.size() > 0) || state.multisig)
+    {
+      fail_msg_writer() << tr("Wallet state does not allow changing Wownero addresses anymore");
+      return;
+    }
+  }
+  ms.set_member(state, index, label, transport_address, monero_address);
+}
+
+void simple_wallet::mms_list(const std::vector<std::string> &args)
+{
+  mms::message_store& ms = m_wallet->get_message_store();
+  if (args.size() != 1)
+  {
+    fail_msg_writer() << tr("Usage: mms list");
+    return;
+  }
+  LOCK_IDLE_SCOPE();
+  const std::vector<mms::message> &messages = ms.get_all_messages();
+  list_mms_messages(messages);
+}
+
+void simple_wallet::mms_next(const std::vector<std::string> &args)
+{
+  mms::message_store& ms = m_wallet->get_message_store();
+  if ((args.size() > 2) || ((args.size() == 2) && (args[1] != "sync")))
+  {
+    fail_msg_writer() << tr("Usage: mms next [sync]");
+    return;
+  }
+  if (!ms.member_info_complete())
+  {
+    fail_msg_writer() << tr("Member info is not yet complete");
+    return;
+  }
+  bool avail = false;
+  std::vector<mms::processing_data> data_list;
+  bool force_sync = false;
+  uint32_t choice = 0;
+  {
+    LOCK_IDLE_SCOPE();
+    if ((args.size() > 1) && (args[1] == "sync"))
+    {
+      // Force the MMS to process any waiting sync info although on its own it would just ignore
+      // those messages because no need to process them can be seen
+      force_sync = true;
+    }
+    string wait_reason;
+    {
+      avail = ms.get_processable_messages(get_multisig_wallet_state(), force_sync, data_list, wait_reason);
+    }
+    if (avail)
+    {
+      avail = choose_mms_processing(data_list, choice);
+    }
+    else if (!wait_reason.empty())
+    {
+      success_msg_writer() << tr("No next step: ") << wait_reason;
+    }
+  }
+  if (avail)
+  {
+    mms::processing_data data = data_list[choice];
+    m_command_successful = false;
+    switch(data.processing)
+    {
+    case mms::message_processing::prepare_multisig:
+      success_msg_writer() << tr("prepare_multisig");
+      m_called_by_mms = true;
+      prepare_multisig(std::vector<std::string>());
+      break;
+
+    case mms::message_processing::make_multisig:
+    {
+      success_msg_writer() << tr("make_multisig");
+      uint32_t number_of_key_sets = data.message_ids.size();
+      std::vector<std::string> sig_args(number_of_key_sets + 1);
+      sig_args[0] = std::to_string(ms.get_threshold());
+      for (size_t i = 0; i < number_of_key_sets; ++i)
+      {
+	mms::message m = ms.get_message_by_id(data.message_ids[i]);
+	sig_args[i+1] = m.content;
+      }
+      m_called_by_mms = true;
+      make_multisig(sig_args);
+      break;
+    }
+
+    case mms::message_processing::finalize_multisig:
+    {
+      success_msg_writer() << tr("finalize_multisig");
+      uint32_t number_of_key_sets = data.message_ids.size();
+      // Other than "make_multisig" only the key sets as parameters, no threshold
+      std::vector<std::string> sig_args(number_of_key_sets);
+      for (size_t i = 0; i < number_of_key_sets; ++i)
+      {
+	mms::message m = ms.get_message_by_id(data.message_ids[i]);
+	sig_args[i] = m.content;
+      }
+      m_called_by_mms = true;
+      finalize_multisig(sig_args);
+      break;
+    }
+
+    case mms::message_processing::create_sync_data:
+    {
+      success_msg_writer() << tr("export_multisig_info");
+      std::vector<std::string> export_args;
+      export_args.push_back("MMS");  // dummy filename
+      m_called_by_mms = true;
+      export_multisig(export_args);
+      break;
+    }
+
+    case mms::message_processing::process_sync_data:
+    {
+      success_msg_writer() << tr("import_multisig_info");
+      std::vector<std::string> import_args;
+      for (size_t i = 0; i < data.message_ids.size(); ++i)
+      {
+	mms::message m = ms.get_message_by_id(data.message_ids[i]);
+	import_args.push_back(m.content);
+      }
+      m_called_by_mms = true;
+      import_multisig(import_args);
+      break;
+    }
+
+    case mms::message_processing::sign_tx:
+    {
+      success_msg_writer() << tr("sign_multisig");
+      std::vector<std::string> sign_args;
+      mms::message m = ms.get_message_by_id(data.message_ids[0]);
+      sign_args.push_back(m.content);
+      m_called_by_mms = true;
+      sign_multisig(sign_args);
+      break;
+    }
+
+    case mms::message_processing::submit_tx:
+    {
+      success_msg_writer() << tr("submit_multisig");
+      std::vector<std::string> submit_args;
+      mms::message m = ms.get_message_by_id(data.message_ids[0]);
+      submit_args.push_back(m.content);
+      m_called_by_mms = true;
+      submit_multisig(submit_args);
+      break;
+    }
+
+    case mms::message_processing::send_tx:
+    {
+      success_msg_writer() << tr("send tx");
+      mms::message m = ms.get_message_by_id(data.message_ids[0]);
+      ms.add_message(get_multisig_wallet_state(), data.receiving_member_index, m.type, mms::message_direction::out,
+		     m.content);
+      m_command_successful = true;
+      break;
+    }
+
+    default:
+      message_writer() << tr("Nothing ready to process");
+      break;
+    }
+
+    if (m_command_successful) {
+      {
+        LOCK_IDLE_SCOPE();
+        ms.set_messages_processed(data);
+        ask_send_all_ready_messages();
+      }
+    }
+  }
+}
+
+void simple_wallet::mms_sync(const std::vector<std::string> &args)
+{
+  mms::message_store& ms = m_wallet->get_message_store();
+  if (args.size() != 1)
+  {
+    fail_msg_writer() << tr("Usage: mms sync");
+    return;
+  }
+  // Force the start of a new sync round, for exceptional cases where something went wrong
+  // Can e.g. solve the problem "This signature was made with stale data" after trying to
+  // create 2 transactions in a row somehow
+  // Code is identical to the code for 'message_processing::create_sync_data'
+  success_msg_writer() << tr("export_multisig_info");
+  std::vector<std::string> export_args;
+  export_args.push_back("MMS");  // dummy filename
+  m_called_by_mms = true;
+  export_multisig(export_args);
+  ask_send_all_ready_messages();
+}
+
+void simple_wallet::mms_transfer(const std::vector<std::string> &args)
+{
+  // It's too complicated to check any arguments here, just let 'transfer' do the whole job
+  std::vector<std::string> transfer_args = args;
+  transfer_args.erase(transfer_args.begin());
+  m_called_by_mms = true;
+  transfer_new(transfer_args);
+}
+
+void simple_wallet::mms_delete(const std::vector<std::string> &args)
+{
+  if (args.size() != 2)
+  {
+    fail_msg_writer() << tr("Usage: mms delete <message_id> | all");
+    return;
+  }
+  LOCK_IDLE_SCOPE();
+  mms::message_store& ms = m_wallet->get_message_store();
+  if (args[1] == "all")
+  {
+    if (user_confirms(tr("Delete all messages?")))
+    {
+      ms.delete_all_messages();
+    }
+  }
+  else
+  {
+    mms::message m;
+    bool valid_id = get_message_from_arg(args[1], m);
+    if (valid_id)
+    {
+      // For the moment, just delete, even if unsent / unprocessed: This is CLI, assume people know what they do
+      ms.delete_message(m.id);
+    }
+  }
+}
+
+void simple_wallet::mms_send(const std::vector<std::string> &args)
+{
+  if (args.size() == 1)
+  {
+    ask_send_all_ready_messages();
+    return;
+  }
+  else if (args.size() != 2)
+  {
+    fail_msg_writer() << tr("Usage: mms send [<message_id>]");
+    return;
+  }
+  LOCK_IDLE_SCOPE();
+  mms::message_store& ms = m_wallet->get_message_store();
+  mms::message m;
+  bool valid_id = get_message_from_arg(args[1], m);
+  if (valid_id)
+  {
+    ms.send_message(get_multisig_wallet_state(), m.id);
+  }
+}
+
+void simple_wallet::mms_receive(const std::vector<std::string> &args)
+{
+  std::vector<mms::message> new_messages;
+  LOCK_IDLE_SCOPE();
+  mms::message_store& ms = m_wallet->get_message_store();
+  bool avail = ms.check_for_messages(get_multisig_wallet_state(), new_messages);
+  if (avail)
+  {
+    list_mms_messages(new_messages);
+  }
+}
+
+void simple_wallet::mms_note(const std::vector<std::string> &args)
+{
+  mms::message_store& ms = m_wallet->get_message_store();
+  if (args.size() == 1)
+  {
+    LOCK_IDLE_SCOPE();
+    const std::vector<mms::message> &messages = ms.get_all_messages();
+    for (size_t i = 0; i < messages.size(); ++i)
+    {
+      const mms::message &m = messages[i];
+      if ((m.type == mms::message_type::note) && (m.state == mms::message_state::waiting))
+      {
+	show_message(m);
+      }
+    }
+    return;
+  }
+  if (args.size() < 3)
+  {
+    fail_msg_writer() << tr("Usage: mms note [<label> <text>]");
+    return;
+  }
+  uint32_t member_index;
+  bool found = ms.get_member_index_by_label(args[1], member_index);
+  if (!found)
+  {
+    fail_msg_writer() << tr("No coalition member found with label ") << args[1];
+    return;
+  }
+  std::string note = "";
+  for (size_t n = 2; n < args.size(); ++n)
+  {
+    if (n > 2)
+    {
+      note += " ";
+    }
+    note += args[n];
+  }
+  LOCK_IDLE_SCOPE();
+  ms.add_message(get_multisig_wallet_state(), member_index, mms::message_type::note,
+		 mms::message_direction::out, note);
+  ask_send_all_ready_messages();
+}
+
+void simple_wallet::mms_show(const std::vector<std::string> &args)
+{
+  if (args.size() != 2)
+  {
+    fail_msg_writer() << tr("Usage: mms show <message_id>");
+    return;
+  }
+  LOCK_IDLE_SCOPE();
+  mms::message_store& ms = m_wallet->get_message_store();
+  mms::message m;
+  bool valid_id = get_message_from_arg(args[1], m);
+  if (valid_id)
+  {
+    show_message(m);
+  }
+}
+
+void simple_wallet::mms_set(const std::vector<std::string> &args)
+{
+  bool set = args.size() == 3;
+  bool query = args.size() == 2;
+  if (!set && !query)
+  {
+    fail_msg_writer() << tr("Usage: mms set <option_name> [<option_value>]");
+    return;
+  }
+  mms::message_store& ms = m_wallet->get_message_store();
+  if (args[1] == "auto-send")
+  {
+    if (set)
+    {
+      bool result;
+      bool ok = parse_bool(args[2], result);
+      if (ok)
+      {
+	ms.set_auto_send(result);
+      }
+      else
+      {
+	fail_msg_writer() << tr("Wrong option value");
+      }
+    }
+    else
+    {
+      success_msg_writer() << (ms.get_auto_send() ? tr("Auto-send is on") : tr("Auto-send is off"));
+    }
+  }
+  else
+  {
+    fail_msg_writer() << tr("Unknown option");
+  }
+}
+
+void simple_wallet::mms_help(const std::vector<std::string> &args)
+{
+  if (args.size() != 2)
+  {
+    fail_msg_writer() << tr("Usage: mms help <subcommand>");
+    return;
+  }
+  std::vector<std::string> help_args;
+  help_args.push_back("mms");
+  help_args.push_back(args[1]);
+  help_advanced(help_args);
+}
+
+bool simple_wallet::mms(const std::vector<std::string> &args)
+{
+  try
+  {
+    mms::message_store& ms = m_wallet->get_message_store();
+    if (args.size() == 0)
+    {
+      if (ms.get_active())
+      {
+	mms_info(args);
+      }
+      else
+      {
+	success_msg_writer() << tr("The MMS is not active.");
+      }
+    }
+    else if (args[0] == "init")
+    {
+      mms_init(args);
+    }
+    else if (!ms.get_active())
+    {
+      fail_msg_writer() << tr("The MMS is not active. Activate using the \"mms init\" command");
+    }
+    else if (args[0] == "info")
+    {
+      mms_info(args);
+    }
+    else if (args[0] == "member")
+    {
+      mms_member(args);
+    }
+    else if (args[0] == "list")
+    {
+      mms_list(args);
+    }
+    else if (args[0] == "next")
+    {
+      mms_next(args);
+    }
+    else if (args[0] == "sync")
+    {
+      mms_sync(args);
+    }
+    else if (args[0] == "transfer")
+    {
+      mms_transfer(args);
+    }
+    else if (args[0] == "delete")
+    {
+      mms_delete(args);
+    }
+    else if (args[0] == "send")
+    {
+      mms_send(args);
+    }
+    else if (args[0] == "receive")
+    {
+      mms_receive(args);
+    }
+    else if (args[0] == "note")
+    {
+      mms_note(args);
+    }
+    else if (args[0] == "show")
+    {
+      mms_show(args);
+    }
+    else if (args[0] == "set")
+    {
+      mms_set(args);
+    }
+    else if (args[0] == "help")
+    {
+      mms_help(args);
+    }
+    else
+    {
+      fail_msg_writer() << tr("Invalid MMS subcommand");
+    }
+  }
+  catch (const tools::error::no_connection_to_daemon &e)
+  {
+    fail_msg_writer() << tr("Error in MMS command: ") << e.what() << " " << e.request();
+  }
+  catch (const std::exception &e)
+  {
+    fail_msg_writer() << tr("Error in MMS command: ") << e.what();
+    return true;
+  }
+  return true;
+}
+// End MMS ------------------------------------------------------------------------------------------------
+
 bool simple_wallet::print_ring(const std::vector<std::string> &args)
 {
   crypto::key_image key_image;
@@ -1973,6 +2878,12 @@ bool simple_wallet::help_advanced(const std::vector<std::string> &args/* = std::
   {
     success_msg_writer() << get_commands_str();
   }
+  else if ((args.size() == 2) && (args.front() == "mms"))
+  {
+    // Little hack to be able to do "help mms <subcommand>"
+    std::vector<std::string> mms_args(1, args.front() + " " + args.back());
+    success_msg_writer() << get_command_usage(mms_args);
+  }
   else
   {
     success_msg_writer() << get_command_usage(args);
@@ -2282,6 +3193,67 @@ simple_wallet::simple_wallet()
                            boost::bind(&simple_wallet::export_raw_multisig, this, _1),
                            tr("export_raw_multisig_tx <filename>"),
                            tr("Export a signed multisig transaction to a file"));
+  m_cmd_binder.set_handler("mms",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms [<subcommand> [<subcommand_parameters>]]"),
+                           tr("Interface with the MMS (Multisig Messaging System)\n"
+			      "subcommand is one of: init, info, member, list, next, sync, transfer, delete, send, receive, note, show, set, help\n"
+			      "Get help about a subcommand with: help_advanced mms <subcommand>, or: mms help <subcommand>"));
+  m_cmd_binder.set_handler("mms init",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms init <threshold>/<coalition_size> <own_label> <own_transport_address>"),
+                           tr("Initialize and configure the MMS"));
+  m_cmd_binder.set_handler("mms info",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms info"),
+                           tr("Display current MMS configuration"));
+  m_cmd_binder.set_handler("mms member",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms member [<number> <label> [<transport_address> [<wownero_address>]]]"),
+                           tr("Set or modify coalition member info (single-word label, transport address, Wownero address), or list all members"));
+  m_cmd_binder.set_handler("mms list",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms list"),
+                           tr("List all messages"));
+  m_cmd_binder.set_handler("mms next",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms next [sync]"),
+                           tr("Evaluate the next possible multisig-related action(s) according to wallet state, and execute or offer for choice\n"
+			      "By using 'sync' processing of waiting messages with multisig sync info can be forced regardless of wallet state"));
+  m_cmd_binder.set_handler("mms sync",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms sync"),
+                           tr("Force generation of multisig sync info regardless of wallet state, to recover from special situations like \"stale data\" errors"));
+  m_cmd_binder.set_handler("mms transfer",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms transfer <transfer_command_arguments>"),
+                           tr("Initiate transfer with MMS support; arguments identical to normal 'transfer' command arguments, for info see there"));
+  m_cmd_binder.set_handler("mms delete",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms delete <message id> | all"),
+                           tr("Delete a single message by giving its id, or delete all messages by using 'all'"));
+  m_cmd_binder.set_handler("mms send",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms send [<message id>]"),
+                           tr("Send a single message by giving its id, or send all waiting messages"));
+  m_cmd_binder.set_handler("mms receive",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms receive"),
+                           tr("Check right away for new messages to receive"));
+  m_cmd_binder.set_handler("mms note",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms note [<label> <text>]"),
+                           tr("Send a one-line message to a coalition member, identified by its label, or show any waiting unread notes"));
+  m_cmd_binder.set_handler("mms show",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms show <message_id>"),
+                           tr("Show detailed info about a single message"));
+  m_cmd_binder.set_handler("mms set",
+                           boost::bind(&simple_wallet::mms, this, _1),
+                           tr("mms set <option_name> [<option_value>]"),
+                           tr("Available options:\n "
+                                  "auto-send <1|0>\n "
+                                  "  Whether to automatically send newly generated messages right away.\n "));
   m_cmd_binder.set_handler("print_ring",
                            boost::bind(&simple_wallet::print_ring, this, _1),
                            tr("print_ring <key_image> | <txid>"),
@@ -4326,6 +5298,8 @@ bool simple_wallet::print_ring_members(const std::vector<tools::wallet2::pending
 bool simple_wallet::transfer_main(int transfer_type, const std::vector<std::string> &args_)
 {
 //  "transfer [index=<N1>[,<N2>,...]] [<priority>] <address> <amount> [<payment_id>]"
+  m_command_successful = false;
+  bool by_mms = called_by_mms();
   if (m_wallet->ask_password() && !get_and_verify_password()) { return true; }
   if (!try_connect_to_daemon())
     return true;
@@ -4651,12 +5625,22 @@ bool simple_wallet::transfer_main(int transfer_type, const std::vector<std::stri
     }
 
     // actually commit the transactions
-    if (m_wallet->multisig())
+    if (m_wallet->multisig() && by_mms)
+    {
+      std::string ciphertext = m_wallet->save_multisig_tx(ptx_vector);
+      if (!ciphertext.empty())
+      {
+	get_message_store().process_wallet_created_data(get_multisig_wallet_state(), mms::message_type::partially_signed_tx, ciphertext);
+	success_msg_writer(true) << tr("Unsigned transaction(s) successfully written to MMS");
+	m_command_successful = true;
+      }
+    }
+    else if (m_wallet->multisig())
     {
       bool r = m_wallet->save_multisig_tx(ptx_vector, "multisig_wownero_tx");
       if (!r)
       {
-        fail_msg_writer() << tr("Failed to write transaction(s) to file");
+	fail_msg_writer() << tr("Failed to write transaction(s) to file");
       }
       else
       {
@@ -6027,9 +7011,9 @@ bool simple_wallet::show_transfers(const std::vector<std::string> &args_)
     fail_msg_writer() << tr("usage: show_transfers [in|out|all|pending|failed] [index=<N1>[,<N2>,...]] [<min_height> [<max_height>]]");
     return true;
   }
-
-  LOCK_IDLE_SCOPE();
   
+  LOCK_IDLE_SCOPE();
+
   // optional in/out selector
   if (local_args.size() > 0) {
     if (local_args[0] == "in" || local_args[0] == "incoming") {
@@ -6344,6 +7328,21 @@ bool simple_wallet::rescan_blockchain(const std::vector<std::string> &args_)
   return refresh_main(0, true);
 }
 //----------------------------------------------------------------------------------------------------
+void simple_wallet::check_for_messages()
+{
+  try {
+    std::vector<mms::message> new_messages;
+    bool new_message = get_message_store().check_for_messages(get_multisig_wallet_state(), new_messages);
+    if (new_message)
+    {
+      message_writer(console_color_magenta, true) << tr("MMS received new message");
+      list_mms_messages(new_messages);
+      m_cmd_binder.print_prompt();
+    }
+  }
+  catch(...) {}
+}
+//----------------------------------------------------------------------------------------------------
 void simple_wallet::wallet_idle_thread()
 {
   while (true)
@@ -6366,6 +7365,14 @@ void simple_wallet::wallet_idle_thread()
       m_auto_refresh_refreshing = false;
     }
 
+    // Check for new MMS messages;
+    // For simplicity auto message check is ALSO controlled by "m_auto_refresh_enabled" and has no
+    // separate thread either; thread syncing is tricky enough with only this one idle thread here
+    if (m_auto_refresh_enabled && get_message_store().get_active())
+    {
+      check_for_messages();
+    }
+
     if (!m_idle_run.load(std::memory_order_relaxed))
       break;
     m_idle_cond.wait_for(lock, boost::chrono::seconds(90));
diff --git a/src/simplewallet/simplewallet.h b/src/simplewallet/simplewallet.h
index 8157ce9a2..138b3455b 100644
--- a/src/simplewallet/simplewallet.h
+++ b/src/simplewallet/simplewallet.h
@@ -210,6 +210,7 @@ namespace cryptonote
     bool sign_multisig(const std::vector<std::string>& args);
     bool submit_multisig(const std::vector<std::string>& args);
     bool export_raw_multisig(const std::vector<std::string>& args);
+    bool mms(const std::vector<std::string>& args);
     bool print_ring(const std::vector<std::string>& args);
     bool set_ring(const std::vector<std::string>& args);
     bool save_known_rings(const std::vector<std::string>& args);
@@ -351,5 +352,38 @@ namespace cryptonote
     bool m_auto_refresh_refreshing;
     std::atomic<bool> m_in_manual_refresh;
     uint32_t m_current_subaddress_account;
+
+    // MMS
+    mms::message_store& get_message_store() const { return m_wallet->get_message_store(); };
+    mms::multisig_wallet_state get_multisig_wallet_state() const { return m_wallet->get_multisig_wallet_state(); };
+    bool mms_active() const { return get_message_store().get_active(); };
+    bool choose_mms_processing(const std::vector<mms::processing_data> &data_list, uint32_t &choice);
+    void list_mms_messages(const std::vector<mms::message> &messages);
+    void show_message(const mms::message &m);
+    void ask_send_all_ready_messages();
+    void check_for_messages();
+    bool user_confirms(const std::string &question);
+    bool get_message_from_arg(const std::string &arg, mms::message &m);
+    bool get_number_from_arg(const std::string &arg, uint32_t &number, const uint32_t lower_bound, const uint32_t upper_bound);
+
+    void mms_init(const std::vector<std::string> &args);
+    void mms_info(const std::vector<std::string> &args);
+    void mms_member(const std::vector<std::string> &args);
+    void mms_list(const std::vector<std::string> &args);
+    void mms_next(const std::vector<std::string> &args);
+    void mms_sync(const std::vector<std::string> &args);
+    void mms_transfer(const std::vector<std::string> &args);
+    void mms_delete(const std::vector<std::string> &args);
+    void mms_send(const std::vector<std::string> &args);
+    void mms_receive(const std::vector<std::string> &args);
+    void mms_note(const std::vector<std::string> &args);
+    void mms_show(const std::vector<std::string> &args);
+    void mms_set(const std::vector<std::string> &args);
+    void mms_help(const std::vector<std::string> &args);
+    void mms_debug(const std::vector<std::string> &args);
+
+    bool m_called_by_mms = false;
+    bool called_by_mms();
+    bool m_command_successful;
   };
 }
diff --git a/src/wallet/CMakeLists.txt b/src/wallet/CMakeLists.txt
index 258f7bed9..d8f582459 100644
--- a/src/wallet/CMakeLists.txt
+++ b/src/wallet/CMakeLists.txt
@@ -34,7 +34,10 @@ set(wallet_sources
   wallet2.cpp
   wallet_args.cpp
   ringdb.cpp
-  node_rpc_proxy.cpp)
+  node_rpc_proxy.cpp
+  message_store.cpp
+  message_transporter.cpp
+)
 
 set(wallet_private_headers
   wallet2.h
@@ -44,7 +47,9 @@ set(wallet_private_headers
   wallet_rpc_server_commands_defs.h
   wallet_rpc_server_error_codes.h
   ringdb.h
-  node_rpc_proxy.h)
+  node_rpc_proxy.h
+  message_store.h
+  message_transporter.h)
 
 monero_private_headers(wallet
   ${wallet_private_headers})
@@ -102,7 +107,6 @@ set_property(TARGET wallet_rpc_server
     OUTPUT_NAME "wownero-wallet-rpc")
 install(TARGETS wallet_rpc_server DESTINATION bin)
 
-
 # build and install libwallet_merged only if we building for GUI
 if (BUILD_GUI_DEPS)
     set(libs_to_merge
diff --git a/src/wallet/message_store.cpp b/src/wallet/message_store.cpp
new file mode 100644
index 000000000..1c0cb2c1c
--- /dev/null
+++ b/src/wallet/message_store.cpp
@@ -0,0 +1,1003 @@
+// Copyright (c) 2014-2018, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
+
+#include "message_store.h"
+#include <boost/archive/portable_binary_oarchive.hpp>
+#include <boost/archive/portable_binary_iarchive.hpp>
+#include <boost/format.hpp>
+#include <fstream>
+#include <sstream>
+#include "file_io_utils.h"
+#include "storages/http_abstract_invoke.h"
+#include "wallet_errors.h"
+#include "serialization/binary_utils.h"
+
+#undef MONERO_DEFAULT_LOG_CATEGORY
+#define MONERO_DEFAULT_LOG_CATEGORY "wallet.mms"
+
+namespace mms
+{
+static std::string get_human_readable_timestamp(uint64_t ts)
+{
+  char buffer[64];
+  time_t tt = ts;
+  struct tm tm;
+#ifdef WIN32
+  gmtime_s(&tm, &tt);
+#else
+  gmtime_r(&tt, &tm);
+#endif
+  strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", &tm);
+  return std::string(buffer);
+}
+
+message_store::message_store() {
+  m_active = false;
+  m_auto_send = false;
+  m_next_message_id = 1;
+  m_coalition_size = 0;
+  m_threshold = 0;
+  m_nettype = cryptonote::network_type::UNDEFINED;
+  m_run = true;
+}
+
+namespace
+{
+  // MMS options handling mirrors what "wallet2" is doing for its options, on-demand init and all
+  // It's not very clean to initialize Bitmessage-specific options here, but going one level further
+  // down still into "message_transporter" for that is a little bit too much
+  struct options {
+    const command_line::arg_descriptor<std::string> bitmessage_address = {"bitmessage-address", mms::message_store::tr("Use PyBitmessage instance at URL <arg>"), "http://localhost:8442/"};
+    const command_line::arg_descriptor<std::string> bitmessage_login = {"bitmessage-login", mms::message_store::tr("Specify <arg> as username:password for PyBitmessage API"), "username:password"};
+  };
+}
+
+void message_store::init_options(boost::program_options::options_description& desc_params)
+{
+  const options opts{};
+  command_line::add_arg(desc_params, opts.bitmessage_address);
+  command_line::add_arg(desc_params, opts.bitmessage_login);
+}
+
+void message_store::init(const multisig_wallet_state &state, const std::string &own_label,
+			 const std::string &own_transport_address, uint32_t coalition_size, uint32_t threshold)
+{
+  m_coalition_size = coalition_size;
+  m_threshold = threshold;
+  m_members.clear();
+  m_messages.clear();
+  m_next_message_id = 1;
+
+  coalition_member member;
+  member.label.clear();
+  member.transport_address.clear();
+  member.monero_address_known = false;
+  memset(&member.monero_address, 0, sizeof(cryptonote::account_public_address));
+  member.index = 0;
+
+  for (size_t i = 0; i < m_coalition_size; ++i) {
+    member.me = member.index == 0;    // Simple convention/automatism for now: The very first member is fixed as / must be "me"
+    m_members.push_back(member);
+    member.index++;
+  }
+
+  set_member(state, 0, own_label, own_transport_address, state.address);
+
+  m_nettype = state.nettype;
+  set_active(true);
+  m_filename = state.mms_file;
+  save(state);
+}
+
+void message_store::set_options(const boost::program_options::variables_map& vm)
+{
+  const options opts{};
+  auto bitmessage_address = command_line::get_arg(vm, opts.bitmessage_address);
+  auto bitmessage_login = command_line::get_arg(vm, opts.bitmessage_login);
+  set_options(bitmessage_address, bitmessage_login);
+}
+
+void message_store::set_options(const std::string &bitmessage_address, const std::string &bitmessage_login)
+{
+  m_transporter.set_options(bitmessage_address, bitmessage_login);
+}
+
+void message_store::set_member(const multisig_wallet_state &state,
+			       uint32_t index,
+                               const boost::optional<std::string> &label,
+                               const boost::optional<std::string> &transport_address,
+                               const boost::optional<cryptonote::account_public_address> monero_address)
+{
+  THROW_WALLET_EXCEPTION_IF(index >= m_coalition_size, tools::error::wallet_internal_error, "Invalid member index " + index);
+  coalition_member &m = m_members[index];
+  if (label)
+  {
+    m.label = label.get();
+  }
+  if (transport_address)
+  {
+    m.transport_address = transport_address.get();
+  }
+  if (monero_address)
+  {
+    m.monero_address_known = true;
+    m.monero_address = monero_address.get();
+  }
+  // Save to minimize the chance to loose that info (at least while in beta)
+  save(state);
+}
+
+const coalition_member &message_store::get_member(uint32_t index) const
+{
+  return m_members[index];
+}
+
+bool message_store::member_info_complete() const
+{
+  for (size_t i = 0; i < m_members.size(); ++i) {
+    const coalition_member &m = m_members[i];
+    if (m.label.empty() || m.transport_address.empty() || !m.monero_address_known) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool message_store::get_member_index_by_monero_address(const cryptonote::account_public_address &monero_address, uint32_t &index) const
+{
+  for (size_t i = 0; i < m_members.size(); ++i) {
+    const coalition_member &m = m_members[i];
+    if (m.monero_address == monero_address) {
+      index = m.index;
+      return true;
+    }
+  }
+  MWARNING("No coalition member with Monero address " << account_address_to_string(monero_address));
+  return false;
+}
+
+bool message_store::get_member_index_by_label(const std::string label, uint32_t &index) const
+{
+  for (size_t i = 0; i < m_members.size(); ++i) {
+    const coalition_member &m = m_members[i];
+    if (m.label == label) {
+      index = m.index;
+      return true;
+    }
+  }
+  MWARNING("No coalition member with label " << label);
+  return false;
+}
+
+void message_store::process_wallet_created_data(const multisig_wallet_state &state, message_type type, const std::string &content) {
+  switch(type)
+  {
+  case message_type::key_set:
+    // Result of a "prepare_multisig" command in the wallet
+    // Send the key set to all other members
+  case message_type::finalizing_key_set:
+    // Result of a "make_multisig" command in the wallet in case of N-1/N multisig
+    // Send the finalizing key set to all other members
+  case message_type::multisig_sync_data:
+    // Result of a "export_multisig_info" command in the wallet
+    // Send the sync data to all other members
+    for (size_t i = 1; i < m_members.size(); ++i) {
+      add_message(state, i, type, message_direction::out, content);
+    }
+    break;
+
+  case message_type::partially_signed_tx:
+    // Result of a "transfer" command in the wallet, or a "sign_multisig" command
+    // that did not yet result in the minimum number of signatures required
+    // Create a message "from me to me" as a container for the tx data
+    if (m_threshold == 1)
+    {
+      // Probably rare, but possible: The 1 signature is already enough, correct the type
+      // Easier to correct here than asking all callers to detect this rare special case
+      type = message_type::fully_signed_tx;
+    }
+    add_message(state, 0, type, message_direction::in, content);
+    break;
+
+  case message_type::fully_signed_tx:
+    add_message(state, 0, type, message_direction::in, content);
+    break;
+
+  default:
+    THROW_WALLET_EXCEPTION(tools::error::wallet_internal_error, "Illegal message type " + (uint32_t)type);
+    break;
+  }
+}
+
+uint32_t message_store::add_message(const multisig_wallet_state &state,
+                                    uint32_t member_index, message_type type, message_direction direction,
+				    const std::string &content)
+{
+  message m;
+  m.id = m_next_message_id++;
+  m.type = type;
+  m.direction = direction;
+  m.content = content;
+  m.created = time(NULL);
+  m.modified = m.created;
+  m.sent = 0;
+  m.member_index = member_index;
+  if (direction == message_direction::out)
+  {
+    m.state = message_state::ready_to_send;
+  }
+  else {
+    m.state = message_state::waiting;
+  };
+  m.wallet_height = state.num_transfer_details;
+  m.round = 0;  // Future expansion for fully generalized M/N multisig
+  m.signature_count = 0;  // Future expansion for signature counting when signing txs
+  m.hash = crypto::null_hash;
+  m_messages.push_back(m);
+
+  // Save for every new message right away (at least while in beta)
+  save(state);
+
+  uint32_t id = m_messages.size() - 1;
+  MINFO(boost::format("Added %s message %s for member %s of type %s")
+	  % message_direction_to_string(direction) % id % member_index % message_type_to_string(type));
+  return id;
+}
+
+// Get the index of the message with id "id", return false if not found
+bool message_store::get_message_index_by_id(uint32_t id, uint32_t &index) const
+{
+  for (size_t i = 0; i < m_messages.size(); ++i)
+  {
+    if (m_messages[i].id == id)
+    {
+      index = i;
+      return true;
+    }
+  }
+  MWARNING("No message found with an id of " << id);
+  return false;
+}
+
+// Get the message with id "id" that must exist
+uint32_t message_store::get_message_index_by_id(uint32_t id) const
+{
+  uint32_t index;
+  bool found = get_message_index_by_id(id, index);
+  THROW_WALLET_EXCEPTION_IF(!found, tools::error::wallet_internal_error, "Invalid message id " + id);
+  return index;
+}
+
+// Get the message with id "id", return false if not found
+// This version of the method allows to check whether id is valid without triggering an error
+bool message_store::get_message_by_id(uint32_t id, message &m) const
+{
+  uint32_t index;
+  bool found = get_message_index_by_id(id, index);
+  if (found)
+  {
+    m = m_messages[index];
+  }
+  return found;
+}
+
+// Get the message with id "id" that must exist
+message message_store::get_message_by_id(uint32_t id) const
+{
+  message m;
+  bool found = get_message_by_id(id, m);
+  THROW_WALLET_EXCEPTION_IF(!found, tools::error::wallet_internal_error, "Invalid message id " + id);
+  return m;
+}
+
+bool message_store::any_message_of_type(message_type type, message_direction direction) const
+{
+  for (size_t i = 0; i < m_messages.size(); ++i)
+  {
+    if ((m_messages[i].type == type) && (m_messages[i].direction == direction))
+    {
+      return true;
+    }
+  }
+  return false;
+}
+
+bool message_store::any_message_with_hash(const crypto::hash &hash) const
+{
+  for (size_t i = 0; i < m_messages.size(); ++i)
+  {
+    if (m_messages[i].hash == hash)
+    {
+      return true;
+    }
+  }
+  return false;
+}
+
+// Is in every element of vector 'ids' (except at index 0) a message id i.e. not 0?
+// Mostly used to check whether we have a message for each coalition member except me,
+// with the member index used as index into 'ids'; the element at index 0, for me,
+// is ignored, to make constant subtractions of 1 for indices when filling the
+// vector unnecessary
+bool message_store::message_ids_complete(const std::vector<uint32_t> ids) const
+{
+  for (size_t i = 1 /* and not 0 */; i < ids.size(); ++i)
+  {
+    if (ids[i] == 0)
+    {
+      return false;
+    }
+  }
+  return true;
+}
+
+void message_store::delete_message(uint32_t id)
+{
+  delete_transport_message(id);
+  uint32_t index = get_message_index_by_id(id);
+  m_messages.erase(m_messages.begin() + index);
+}
+
+void message_store::delete_all_messages()
+{
+  for (size_t i = 0; i < m_messages.size(); ++i)
+  {
+    delete_transport_message(m_messages[i].id);
+  }
+  m_messages.clear();
+}
+
+void message_store::write_to_file(const multisig_wallet_state &state, const std::string &filename) {
+  std::stringstream oss;
+  boost::archive::portable_binary_oarchive ar(oss);
+  try
+  {
+    ar << *this;
+  }
+  catch (...)
+  {
+    THROW_WALLET_EXCEPTION_IF(true, tools::error::file_save_error, filename);
+  }
+  std::string buf = oss.str();
+
+  crypto::chacha_key key;
+  crypto::generate_chacha_key(&state.view_secret_key, sizeof(crypto::secret_key), key);
+
+  file_data write_file_data = boost::value_initialized<file_data>();
+  write_file_data.magic_string = "MMS";
+  write_file_data.file_version = 0;
+  write_file_data.iv = crypto::rand<crypto::chacha_iv>();
+  std::string encrypted_data;
+  encrypted_data.resize(buf.size());
+  crypto::chacha20(buf.data(), buf.size(), key, write_file_data.iv, &encrypted_data[0]);
+  write_file_data.encrypted_data = encrypted_data;
+
+  std::stringstream file_oss;
+  boost::archive::portable_binary_oarchive file_ar(file_oss);
+  try
+  {
+    file_ar << write_file_data;
+  }
+  catch (...)
+  {
+    THROW_WALLET_EXCEPTION_IF(true, tools::error::file_save_error, filename);
+  }
+
+  bool success = epee::file_io_utils::save_string_to_file(filename, file_oss.str());
+  THROW_WALLET_EXCEPTION_IF(!success, tools::error::file_save_error, filename);
+}
+
+void message_store::read_from_file(const multisig_wallet_state &state, const std::string &filename)
+{
+  boost::system::error_code ignored_ec;
+  bool file_exists = boost::filesystem::exists(filename, ignored_ec);
+  if (!file_exists) {
+    // Simply do nothing if the file is not there; allows e.g. easy recovery
+    // from problems with the MMS by deleting the file
+    MERROR("No message store file found: " << filename);
+    return;
+  }
+
+  std::string buf;
+  bool success = epee::file_io_utils::load_file_to_string(filename, buf);
+  THROW_WALLET_EXCEPTION_IF(!success, tools::error::file_read_error, filename);
+
+  file_data read_file_data;
+  try
+  {
+    std::stringstream iss;
+    iss << buf;
+    boost::archive::portable_binary_iarchive ar(iss);
+    ar >> read_file_data;
+  }
+  catch (const std::exception &e)
+  {
+    MERROR("MMS file " << filename << " has bad structure <iv,encrypted_data>: " << e.what());
+    THROW_WALLET_EXCEPTION_IF(true, tools::error::file_read_error, filename);
+  }
+
+  crypto::chacha_key key;
+  crypto::generate_chacha_key(&state.view_secret_key, sizeof(crypto::secret_key), key);
+  std::string decrypted_data;
+  decrypted_data.resize(read_file_data.encrypted_data.size());
+  crypto::chacha20(read_file_data.encrypted_data.data(), read_file_data.encrypted_data.size(), key, read_file_data.iv, &decrypted_data[0]);
+
+  try
+  {
+    std::stringstream iss;
+    iss << decrypted_data;
+    boost::archive::portable_binary_iarchive ar(iss);
+    ar >> *this;
+  }
+  catch (const std::exception &e)
+  {
+    MERROR("MMS file " << filename << " has bad structure: " << e.what());
+    THROW_WALLET_EXCEPTION_IF(true, tools::error::file_read_error, filename);
+  }
+
+  m_filename = filename;
+}
+
+// Save to the same file this message store was loaded from
+// Called after changes deemed "important", to make it less probable to loose messages in case of
+// a crash; a better and long-term solution would of course be to use LMDB ...
+void message_store::save(const multisig_wallet_state &state)
+{
+  if (!m_filename.empty())
+  {
+    write_to_file(state, m_filename);
+  }
+}
+
+bool message_store::get_processable_messages(const multisig_wallet_state &state,
+                                             bool force_sync, std::vector<processing_data> &data_list, std::string &wait_reason)
+{
+  uint32_t wallet_height = state.num_transfer_details;
+  data_list.clear();
+  wait_reason.clear();
+  if (m_members.size() < m_coalition_size)
+  {
+    // Unless ALL members are known we can't do anything
+    wait_reason = tr("The list of coalition members is not complete.");
+    return false;
+  }
+
+  if (!state.multisig)
+  {
+    if (!any_message_of_type(message_type::key_set, message_direction::out))
+    {
+      // With the own key set not yet ready we must do "prepare_multisig" first;
+      // Key sets from other members may be here already, but if we process them now
+      // the wallet will go multisig too early: we can't produce our own key set any more!
+      processing_data data;
+      data.processing = message_processing::prepare_multisig;
+      data_list.push_back(data);
+      return true;
+    }
+
+    // Ids of key set messages per member index, to check completeness
+    // Naturally, does not care about the order of the messages and is trivial to secure against
+    // key sets that were received more than once
+    std::vector<uint32_t> key_set_messages(m_coalition_size, 0);
+
+    for (size_t i = 0; i < m_messages.size(); ++i)
+    {
+      message &m = m_messages[i];
+      if ((m.type == message_type::key_set) && (m.state == message_state::waiting))
+      {
+	if (key_set_messages[m.member_index] == 0)
+	{
+	  key_set_messages[m.member_index] = m.id;
+	}
+	// else duplicate key set, ignore
+      }
+    }
+
+    bool key_sets_complete = message_ids_complete(key_set_messages);
+    if (key_sets_complete)
+    {
+      // Nothing else can be ready to process earlier than this, ignore everything else and give back
+      processing_data data;
+      data.processing = message_processing::make_multisig;
+      data.message_ids = key_set_messages;
+      data.message_ids.erase(data.message_ids.begin());
+      data_list.push_back(data);
+      return true;
+    }
+    else
+    {
+      wait_reason = tr("Wallet can't go multisig because key sets from other members missing or not complete.");
+      return false;
+    }
+  }
+
+  if (state.multisig && !state.multisig_is_ready)
+  {
+    // In the case of N-1/N multisig the call 'wallet2::multisig' returns already true
+    // after "make_multisig" but before "finalize_multisig", but returns the parameter
+    // 'ready' as false to document this particular state
+
+    // Same story for finalizing key sets: If all are here we process them
+    // It looks like the "finalize_multisig" command would also process less than all key sets,
+    // and maybe also correctly so, but the MMS does not support that case and insists on completeness
+    std::vector<uint32_t> finalizing_key_set_messages(m_coalition_size, 0);
+
+    for (size_t i = 0; i < m_messages.size(); ++i)
+    {
+      message &m = m_messages[i];
+      if ((m.type == message_type::finalizing_key_set) && (m.state == message_state::waiting))
+      {
+	if (finalizing_key_set_messages[m.member_index] == 0)
+	{
+	  finalizing_key_set_messages[m.member_index] = m.id;
+	}
+	// else duplicate key set, ignore
+      }
+    }
+
+    bool key_sets_complete = message_ids_complete(finalizing_key_set_messages);
+    if (key_sets_complete)
+    {
+      processing_data data;
+      data.processing = message_processing::finalize_multisig;
+      data.message_ids = finalizing_key_set_messages;
+      data.message_ids.erase(data.message_ids.begin());
+      data_list.push_back(data);
+      return true;
+    }
+    else
+    {
+      wait_reason = tr("Wallet can't finalize multisig because key sets from other members missing or not complete.");
+      return false;
+    }
+  }
+
+  // Properly exchanging multisig sync data is easiest and most transparent
+  // for the user if a wallet sends its own data first and processes any received
+  // sync data afterwards so that's the order that the MMS enforces here.
+  // (Technically, it seems to work also the other way round.)
+  //
+  // To check whether a NEW round of syncing is necessary the MMS works with a
+  // "wallet state": new state means new syncing needed.
+  //
+  // The MMS monitors the "wallet state" by recording "wallet heights" as
+  // numbers of transfers present in a wallet at the time of message creation. While
+  // not watertight, this quite simple scheme should already suffice to trigger
+  // and orchestrate a sensible exchange of sync data.
+  if (state.has_multisig_partial_key_images || force_sync)
+  {
+    // Sync is necessary and not yet completed: Processing of transactions
+    // will only be possible again once properly synced
+    // Check first whether we generated already OUR sync info; take note of
+    // any processable sync info from other members on the way in case we need it
+    bool own_sync_data_created = false;
+    std::vector<uint32_t> sync_messages(m_coalition_size, 0);
+    for (size_t i = 0; i < m_messages.size(); ++i)
+    {
+      message &m = m_messages[i];
+      if ((m.type == message_type::multisig_sync_data) && (force_sync || (m.wallet_height == wallet_height)))
+      // It's data for the same "round" of syncing, on the same "wallet height", therefore relevant
+      {
+	if (m.direction == message_direction::out)
+	{
+	  own_sync_data_created = true;
+	  // Ignore whether sent already or not, and assume as complete if several other members there
+	}
+	else if ((m.direction == message_direction::in) && (m.state == message_state::waiting))
+	{
+	  if (sync_messages[m.member_index] == 0)
+	  {
+	    sync_messages[m.member_index] = m.id;
+	  }
+	  // else duplicate sync message, ignore
+	}
+      }
+    }
+    if (!own_sync_data_created) {
+      // As explained above, creating sync data BEFORE processing such data from
+      // other members reliably works, so insist on that here
+      processing_data data;
+      data.processing = message_processing::create_sync_data;
+      data_list.push_back(data);
+      return true;
+    }
+    else if (message_ids_complete(sync_messages))
+    {
+      processing_data data;
+      data.processing = message_processing::process_sync_data;
+      data.message_ids = sync_messages;
+      data.message_ids.erase(data.message_ids.begin());
+      data_list.push_back(data);
+      return true;
+    }
+    else
+    {
+      // We can't proceed to any transactions until we have synced
+      wait_reason = tr("Syncing not possible because multisig sync data from other members missing or not complete.");
+      return false;
+    }
+  }
+
+  bool waiting_found = false;
+  for (size_t i = 0; i < m_messages.size(); ++i)
+  {
+    message &m = m_messages[i];
+    if (m.state == message_state::waiting)
+    {
+      waiting_found = true;
+      if (m.type == message_type::fully_signed_tx)
+      {
+	// We can either submit it ourselves, or send it to any other member for submission
+	processing_data data;
+	data.processing = message_processing::submit_tx;
+	data.message_ids.push_back(m.id);
+	data_list.push_back(data);
+
+	data.processing = message_processing::send_tx;
+	for (size_t j = 1; j < m_members.size(); ++j)
+	{
+	  data.receiving_member_index = j;
+	  data_list.push_back(data);
+	}
+	return true;
+      }
+      else if (m.type == message_type::partially_signed_tx)
+      {
+	if (m.member_index == 0)
+	{
+	  // We started this ourselves, or signed it but with still signatures missing:
+	  // We can send it to any other member for signing / further signing
+	  // In principle it does not make sense to send it back to somebody who
+	  // already signed, but the MMS does not / not yet keep track of that,
+	  // because that would be somewhat complicated.
+	  processing_data data;
+	  data.processing = message_processing::send_tx;
+	  data.message_ids.push_back(m.id);
+	  for (size_t j = 1; j < m_members.size(); ++j)
+	  {
+	    data.receiving_member_index = j;
+	    data_list.push_back(data);
+	  }
+	  return true;
+	}
+	else
+	{
+	  // Somebody else sent this to us: We can sign it
+	  // It would be possible to just pass it on, but that's not directly supported here
+	  processing_data data;
+	  data.processing = message_processing::sign_tx;
+	  data.message_ids.push_back(m.id);
+	  data_list.push_back(data);
+	  return true;
+	}
+      }
+    }
+  }
+  if (waiting_found)
+  {
+    wait_reason = tr("Waiting message is not a tx and thus not processable now.");
+  }
+  else
+  {
+    wait_reason = tr("There is no message waiting to be processed.");
+  }
+
+  return false;
+}
+
+void message_store::set_messages_processed(const processing_data &data)
+{
+  for (size_t i = 0; i < data.message_ids.size(); ++i)
+  {
+    set_message_processed_or_sent(data.message_ids[i]);
+  }
+}
+
+void message_store::set_message_processed_or_sent(uint32_t id)
+{
+  uint32_t index = get_message_index_by_id(id);
+  message &m = m_messages[index];
+  if (m.state == message_state::waiting)
+  {
+    // So far a fairly cautious and conservative strategy: Only delete from Bitmessage
+    // when fully processed (and e.g. not already after reception and writing into
+    // the message store file)
+    delete_transport_message(id);
+    m.state = message_state::processed;
+  }
+  else if (m.state == message_state::ready_to_send)
+  {
+    m.state = message_state::sent;
+  }
+  m.modified = time(NULL);
+}
+
+void message_store::encrypt(uint32_t member_index, const std::string &plaintext,
+			    std::string &ciphertext, crypto::public_key &encryption_public_key, crypto::chacha_iv &iv)
+{
+  crypto::secret_key encryption_secret_key;
+  crypto::generate_keys(encryption_public_key, encryption_secret_key);
+
+  crypto::key_derivation derivation;
+  crypto::public_key dest_view_public_key = m_members[member_index].monero_address.m_view_public_key;
+  bool success = crypto::generate_key_derivation(dest_view_public_key, encryption_secret_key, derivation);
+  THROW_WALLET_EXCEPTION_IF(!success, tools::error::wallet_internal_error, "Failed to generate key derivation for message encryption");
+
+  crypto::chacha_key chacha_key;
+  crypto::generate_chacha_key(&derivation, sizeof(derivation), chacha_key);
+  iv = crypto::rand<crypto::chacha_iv>();
+  ciphertext.resize(plaintext.size());
+  crypto::chacha20(plaintext.data(), plaintext.size(), chacha_key, iv, &ciphertext[0]);
+}
+
+void message_store::decrypt(const std::string &ciphertext, const crypto::public_key &encryption_public_key, const crypto::chacha_iv &iv,
+			    const crypto::secret_key &view_secret_key, std::string &plaintext)
+{
+  crypto::key_derivation derivation;
+  bool success = crypto::generate_key_derivation(encryption_public_key, view_secret_key, derivation);
+  THROW_WALLET_EXCEPTION_IF(!success, tools::error::wallet_internal_error, "Failed to generate key derivation for message decryption");
+  crypto::chacha_key chacha_key;
+  crypto::generate_chacha_key(&derivation, sizeof(derivation), chacha_key);
+  plaintext.resize(ciphertext.size());
+  crypto::chacha20(ciphertext.data(), ciphertext.size(), chacha_key, iv, &plaintext[0]);
+}
+
+void message_store::send_message(const multisig_wallet_state &state, uint32_t id)
+{
+  uint32_t index = get_message_index_by_id(id);
+  message m = m_messages[index];
+  file_transport_message dm;
+  dm.sender_address = m_members[0].monero_address;
+  dm.internal_message = m;
+  encrypt(m.member_index, m.content, dm.internal_message.content, dm.encryption_public_key, dm.iv);
+  std::string transport_address = m_members[m.member_index].transport_address;
+  if (transport_address.find("BM-") == 0)
+  {
+    // Take the transport address of the member as Bitmessage address and use the message transporter
+    transport_message rm;
+    rm.source_monero_address = dm.sender_address;
+    rm.source_transport_address = m_members[0].transport_address;
+    rm.destination_monero_address = m_members[m.member_index].monero_address;
+    rm.destination_transport_address = transport_address;
+    rm.iv = dm.iv;
+    rm.encryption_public_key = dm.encryption_public_key;
+    rm.timestamp = time(NULL);
+    rm.type = (uint32_t)dm.internal_message.type;
+    rm.subject = "MMS V0 " + get_human_readable_timestamp(rm.timestamp);
+    rm.content = dm.internal_message.content;
+    rm.hash = crypto::cn_fast_hash(rm.content.data(), rm.content.size());
+
+    crypto::generate_signature(rm.hash, m_members[0].monero_address.m_view_public_key, state.view_secret_key, rm.signature);
+
+    bool success = m_transporter.send_message(rm);
+  }
+  else
+  {
+    // Take the transport address of the member as a subdirectory and write the message as
+    // file "debug_message" there
+    std::string filename = transport_address + "/debug_message";
+
+    std::stringstream oss;
+    boost::archive::portable_binary_oarchive ar(oss);
+    ar << dm;
+    std::string buf = oss.str();
+    bool r = epee::file_io_utils::save_string_to_file(filename, buf);
+  }
+
+  m_messages[index].state=message_state::sent;
+  m_messages[index].sent= time(NULL);
+}
+
+bool message_store::check_for_messages(const multisig_wallet_state &state, std::vector<message> &messages)
+{
+  m_run.store(true, std::memory_order_relaxed);
+  std::string transport_address = m_members[0].transport_address;
+  if (transport_address.find("BM-") == 0)
+  {
+      // Take the transport address of "me" as Bitmessage address and use the messaging daemon
+    std::vector<transport_message> transport_messages;
+    bool r = m_transporter.receive_messages(m_members[0].monero_address, transport_address, transport_messages);
+    if (!m_run.load(std::memory_order_relaxed))
+    {
+      // Stop was called, don't waste time processing the messages
+      // (but once started processing them, don't react to stop request anymore, avoid receiving them "partially)"
+      return false;
+    }
+
+    bool new_messages = false;
+    for (size_t i = 0; i < transport_messages.size(); ++i)
+    {
+      transport_message rm = transport_messages[i];
+      if (any_message_with_hash(rm.hash))
+      {
+	// Already seen, do not take again
+      }
+      else
+      {
+        uint32_t sender_index;
+	bool found = get_member_index_by_monero_address(rm.source_monero_address, sender_index);
+	if (!found)
+	{
+	  // From an address that is not a member here: Ignore
+	}
+	else
+	{
+	  crypto::hash actual_hash = crypto::cn_fast_hash(rm.content.data(), rm.content.size());
+          THROW_WALLET_EXCEPTION_IF(actual_hash != rm.hash, tools::error::wallet_internal_error, "Message hash mismatch");
+
+	  bool signature_valid = crypto::check_signature(actual_hash, rm.source_monero_address.m_view_public_key, rm.signature);
+          THROW_WALLET_EXCEPTION_IF(!signature_valid, tools::error::wallet_internal_error, "Message signature not valid");
+
+	  std::string plaintext;
+	  decrypt(rm.content, rm.encryption_public_key, rm.iv, state.view_secret_key, plaintext);
+	  uint32_t index = add_message(state, sender_index, (message_type)rm.type, message_direction::in, plaintext);
+	  message &m = m_messages[index];
+	  m.hash = rm.hash;
+	  m.transport_id = rm.transport_id;
+	  m.sent = rm.timestamp;
+	  m.round = rm.round;
+	  m.signature_count = rm.signature_count;
+	  messages.push_back(m);
+	  new_messages = true;
+	}
+      }
+    }
+    return new_messages;
+  }
+  else
+  {
+    // Take the transport address of "me" as a subdirectory and read a single new
+    // message from a file "debug_message" there, assumed to come from member 1
+    std::string filename = m_members[0].transport_address + "/debug_message";
+    boost::system::error_code ignored_ec;
+    bool file_exists = boost::filesystem::exists(filename, ignored_ec);
+    if (!file_exists) {
+      return false;
+    }
+
+    file_transport_message dm;
+    std::string buf;
+    bool r = epee::file_io_utils::load_file_to_string(filename, buf);
+    std::stringstream iss;
+    iss << buf;
+    boost::archive::portable_binary_iarchive ar(iss);
+    ar >> dm;
+
+    uint32_t sender_index;
+    get_member_index_by_monero_address(dm.sender_address, sender_index);
+    std::string plaintext;
+    decrypt(dm.internal_message.content, dm.encryption_public_key, dm.iv, state.view_secret_key, plaintext);
+    add_message(state, sender_index, dm.internal_message.type, message_direction::in, plaintext);
+    boost::filesystem::remove(filename);
+    return true;
+  }
+  return false;
+}
+
+void message_store::delete_transport_message(uint32_t id)
+{
+  uint32_t index = get_message_index_by_id(id);
+  message m = m_messages[index];
+  if (!m.transport_id.empty())
+  {
+    m_transporter.delete_message(m.transport_id);
+  }
+}
+
+std::string message_store::account_address_to_string(const cryptonote::account_public_address &account_address) const
+{
+  return get_account_address_as_str(m_nettype, false, account_address);
+}
+
+const char* message_store::message_type_to_string(message_type type) {
+  switch (type)
+  {
+  case message_type::key_set:
+    return tr("key set");
+  case message_type::finalizing_key_set:
+    return tr("finalizing key set");
+  case message_type::multisig_sync_data:
+    return tr("multisig sync data");
+  case message_type::partially_signed_tx:
+    return tr("partially signed tx");
+  case message_type::fully_signed_tx:
+    return tr("fully signed tx");
+  case message_type::note:
+    return tr("note");
+  default:
+    return tr("unknown message type");
+  }
+}
+
+const char* message_store::message_direction_to_string(message_direction direction) {
+  switch (direction)
+  {
+  case message_direction::in:
+    return tr("in");
+  case message_direction::out:
+    return tr("out");
+  default:
+    return tr("unknown message direction");
+  }
+}
+
+const char* message_store::message_state_to_string(message_state state) {
+  switch (state)
+  {
+  case message_state::ready_to_send:
+    return tr("ready to send");
+  case message_state::sent:
+    return tr("sent");
+  case message_state::waiting:
+    return tr("waiting");
+  case message_state::processed:
+    return tr("processed");
+  case message_state::cancelled:
+    return tr("cancelled");
+  default:
+    return tr("unknown message state");
+  }
+}
+
+// Convert a member to string suitable for a column in a list, with 'max_width'
+// Format: label: transport_address
+std::string message_store::member_to_string(const coalition_member &member, uint32_t max_width) {
+  std::string s = "";
+  s.reserve(max_width);
+  uint32_t avail = max_width;
+  uint32_t label_len = member.label.length();
+  if (label_len > avail)
+  {
+    s.append(member.label.substr(0, avail - 2));
+    s.append("..");
+    return s;
+  }
+  s.append(member.label);
+  avail -= label_len;
+  uint32_t transport_addr_len = member.transport_address.length();
+  if ((transport_addr_len > 0) && (avail > 10))
+  {
+    s.append(": ");
+    avail -= 2;
+    if (transport_addr_len <= avail)
+    {
+      s.append(member.transport_address);
+    }
+    else
+    {
+      s.append(member.transport_address.substr(0, avail-2));
+      s.append("..");
+    }
+  }
+  return s;
+}
+
+
+}
diff --git a/src/wallet/message_store.h b/src/wallet/message_store.h
new file mode 100644
index 000000000..f12bd7d2a
--- /dev/null
+++ b/src/wallet/message_store.h
@@ -0,0 +1,357 @@
+// Copyright (c) 2014-2018, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
+
+#pragma once
+
+#include <cstdlib>
+#include <string>
+#include <vector>
+#include "crypto/hash.h"
+#include <boost/serialization/vector.hpp>
+#include "serialization/serialization.h"
+#include "cryptonote_basic/cryptonote_boost_serialization.h"
+#include "cryptonote_basic/account_boost_serialization.h"
+#include "cryptonote_basic/cryptonote_basic.h"
+#include "common/i18n.h"
+#include "message_transporter.h"
+
+#undef MONERO_DEFAULT_LOG_CATEGORY
+#define MONERO_DEFAULT_LOG_CATEGORY "wallet.mms"
+
+namespace mms
+{
+  enum class message_type
+  {
+    key_set,
+    finalizing_key_set,
+    multisig_sync_data,
+    partially_signed_tx,
+    fully_signed_tx,
+    note
+  };
+
+  enum class message_direction
+  {
+    in,
+    out
+  };
+
+  enum class message_state
+  {
+    ready_to_send,
+    sent,
+
+    waiting,
+    processed,
+
+    cancelled
+  };
+
+  enum class message_processing
+  {
+    prepare_multisig,
+    make_multisig,
+    finalize_multisig,
+    create_sync_data,
+    process_sync_data,
+    sign_tx,
+    send_tx,
+    submit_tx
+  };
+
+  struct message
+  {
+    uint32_t id;
+    message_type type;
+    message_direction direction;
+    std::string content;
+    uint64_t created;
+    uint64_t modified;
+    uint64_t sent;
+    uint32_t member_index;
+    crypto::hash hash;
+    message_state state;
+    uint32_t wallet_height;
+    uint32_t round;
+    uint32_t signature_count;
+    std::string transport_id;
+  };
+  // "wallet_height" (for lack of a short name that would describe what it is about)
+  // is the number of transfers present in the wallet at the time of message
+  // construction; used to coordinate generation of sync info (which depends
+  // on the content of the wallet at time of generation)
+
+  struct coalition_member
+  {
+    std::string label;
+    std::string transport_address;
+    bool monero_address_known;
+    cryptonote::account_public_address monero_address;
+    bool me;
+    uint32_t index;
+  };
+
+  struct processing_data
+  {
+    message_processing processing;
+    std::vector<uint32_t> message_ids;
+    uint32_t receiving_member_index = 0;
+  };
+
+  struct file_transport_message
+  {
+    cryptonote::account_public_address sender_address;
+    crypto::chacha_iv iv;
+    crypto::public_key encryption_public_key;
+    message internal_message;
+  };
+
+  // Overal .mms file structure, with the "message_store" object serialized to and
+  // encrypted in "encrypted_data"
+  struct file_data
+  {
+    std::string magic_string;
+    uint32_t file_version;
+    crypto::chacha_iv iv;
+    std::string encrypted_data;
+  };
+
+    // The following struct provides info about the current state of a "wallet2" object
+  // at the time of a "message_store" method call that those methods need. See on the
+  // one hand a first parameter of this type for several of those methods, and on the
+  // other hand the method "wallet2::get_multisig_wallet_state" which clients like the
+  // CLI wallet can use to get that info.
+  //
+  // Note that in the case of a wallet that is already multisig "address" is NOT the
+  // multisig address, but the "original" wallet address at creation time. Likewise
+  // "view_secret_key" is the original view secret key then.
+  //
+  // This struct definition is here and not in "wallet2.h" to avoid circular imports.
+  struct multisig_wallet_state
+  {
+    cryptonote::account_public_address address;
+    cryptonote::network_type nettype;
+    crypto::secret_key view_secret_key;
+    bool multisig;
+    bool multisig_is_ready;
+    bool has_multisig_partial_key_images;
+    size_t num_transfer_details;
+    std::string mms_file;
+
+    ~multisig_wallet_state()
+    {
+      view_secret_key = crypto::null_skey;
+    }
+  };
+
+  class message_store
+  {
+  public:
+    message_store();
+    // Initialize and start to use the MMS, set the first member, this wallet itself
+    // Filename, if not null and not empty, is used to create the ".mms" file
+    // reset it if already used, with deletion of all members and messages
+    void init(const multisig_wallet_state &state, const std::string &own_label,
+              const std::string &own_transport_address, uint32_t coalition_size, uint32_t threshold);
+    void set_active(bool active) { m_active = active; };
+    void set_auto_send(bool auto_send) { m_auto_send = auto_send; };
+    void set_options(const boost::program_options::variables_map& vm);
+    void set_options(const std::string &bitmessage_address, const std::string &bitmessage_login);
+    bool get_active() const { return m_active; };
+    bool get_auto_send() const { return m_auto_send; };
+    uint32_t get_threshold() const { return m_threshold; };
+    uint32_t get_coalition_size() const { return m_coalition_size; };
+
+    void set_member(const multisig_wallet_state &state,
+                    uint32_t index,
+                    const boost::optional<std::string> &label,
+                    const boost::optional<std::string> &transport_address,
+                    const boost::optional<cryptonote::account_public_address> monero_address);
+
+    const coalition_member &get_member(uint32_t index) const;
+    bool get_member_index_by_monero_address(const cryptonote::account_public_address &monero_address, uint32_t &index) const;
+    bool get_member_index_by_label(const std::string label, uint32_t &index) const;
+    const std::vector<coalition_member> &get_all_members() const { return m_members; };
+    bool member_info_complete() const;
+
+    // Process data just created by "me" i.e. the own local wallet, e.g. as the result of a "prepare_multisig" command
+    // Creates the resulting messages to the right members
+    void process_wallet_created_data(const multisig_wallet_state &state, message_type type, const std::string &content);
+
+    // Go through all the messages, look at the "ready to process" ones, and check whether any single one
+    // or any group of them can be processed, because they are processable as single messages (like a tx
+    // that is fully signed and thus ready for submit to the net) or because they form a complete group
+    // (e.g. key sets from all coalition members to make the wallet multisig). If there are multiple
+    // candidates, e.g. in 2/3 multisig sending to one OR the other member to sign, there will be more
+    // than 1 element in 'data' for the user to choose. If nothing is ready "false" is returned.
+    // The method mostly ignores the order in which the messages were received because messages may be delayed
+    // (e.g. sync data from a member arrives AFTER a transaction to submit) or because message time stamps
+    // may be wrong so it's not possible to order them reliably.
+    // Messages also may be ready by themselves but the wallet not yet ready for them (e.g. sync data already
+    // arriving when the wallet is not yet multisig because key sets were delayed or were lost altogether.)
+    // If nothing is ready 'wait_reason' may contain further info about the reason why.
+    bool get_processable_messages(const multisig_wallet_state &state,
+                                  bool force_sync,
+                                  std::vector<processing_data> &data_list,
+                                  std::string &wait_reason);
+    void set_messages_processed(const processing_data &data);
+
+    uint32_t add_message(const multisig_wallet_state &state,
+                         uint32_t member_index, message_type type, message_direction direction,
+                         const std::string &content);
+    const std::vector<message> &get_all_messages() const { return m_messages; };
+    bool get_message_by_id(uint32_t id, message &m) const;
+    message get_message_by_id(uint32_t id) const;
+    void set_message_processed_or_sent(uint32_t id);
+    void delete_message(uint32_t id);
+    void delete_all_messages();
+
+    void send_message(const multisig_wallet_state &state, uint32_t id);
+    bool check_for_messages(const multisig_wallet_state &state, std::vector<message> &messages);
+    void stop() { m_run.store(false, std::memory_order_relaxed); m_transporter.stop(); }
+
+    void write_to_file(const multisig_wallet_state &state, const std::string &filename);
+    void read_from_file(const multisig_wallet_state &state, const std::string &filename);
+
+    template <class t_archive>
+    inline void serialize(t_archive &a, const unsigned int ver)
+    {
+      a & m_active;
+      a & m_coalition_size;
+      a & m_nettype;
+      a & m_threshold;
+      a & m_members;
+      a & m_messages;
+      a & m_next_message_id;
+      a & m_auto_send;
+    }
+
+    const char* message_type_to_string(message_type type);
+    const char* message_direction_to_string(message_direction direction);
+    const char* message_state_to_string(message_state state);
+    std::string member_to_string(const coalition_member &member, uint32_t max_width);
+
+    static const char *tr(const char *str) { return i18n_translate(str, "tools::mms"); }
+    static void init_options(boost::program_options::options_description& desc_params);
+
+  private:
+    bool m_active;
+    uint32_t m_coalition_size;
+    uint32_t m_threshold;
+    bool m_auto_send;
+    cryptonote::network_type m_nettype;
+    std::vector<coalition_member> m_members;
+    std::vector<message> m_messages;
+    uint32_t m_next_message_id;
+    std::string m_filename;
+    message_transporter m_transporter;
+    std::atomic<bool> m_run;
+
+    bool get_message_index_by_id(uint32_t id, uint32_t &index) const;
+    uint32_t get_message_index_by_id(uint32_t id) const;
+    bool any_message_of_type(message_type type, message_direction direction) const;
+    bool any_message_with_hash(const crypto::hash &hash) const;
+    bool message_ids_complete(const std::vector<uint32_t> ids) const;
+    void encrypt(uint32_t member_index, const std::string &plaintext,
+                 std::string &ciphertext, crypto::public_key &encryption_public_key, crypto::chacha_iv &iv);
+    void decrypt(const std::string &ciphertext, const crypto::public_key &encryption_public_key, const crypto::chacha_iv &iv,
+                 const crypto::secret_key &view_secret_key, std::string &plaintext);
+    void delete_transport_message(uint32_t id);
+    std::string account_address_to_string(const cryptonote::account_public_address &account_address) const;
+    void save(const multisig_wallet_state &state);
+  };
+}
+
+BOOST_CLASS_VERSION(mms::file_data, 0)
+BOOST_CLASS_VERSION(mms::message_store, 0)
+BOOST_CLASS_VERSION(mms::message, 0)
+BOOST_CLASS_VERSION(mms::file_transport_message, 0)
+BOOST_CLASS_VERSION(mms::coalition_member, 0)
+
+namespace boost
+{
+  namespace serialization
+  {
+    template <class Archive>
+    inline void serialize(Archive &a, mms::file_data &x, const boost::serialization::version_type ver)
+    {
+      a & x.magic_string;
+      a & x.file_version;
+      a & x.iv;
+      a & x.encrypted_data;
+    }
+
+    template <class Archive>
+    inline void serialize(Archive &a, mms::message &x, const boost::serialization::version_type ver)
+    {
+      a & x.id;
+      a & x.type;
+      a & x.direction;
+      a & x.content;
+      a & x.created;
+      a & x.modified;
+      a & x.sent;
+      a & x.member_index;
+      a & x.hash;
+      a & x.state;
+      a & x.wallet_height;
+      a & x.round;
+      a & x.signature_count;
+      a & x.transport_id;
+    }
+
+    template <class Archive>
+    inline void serialize(Archive &a, mms::coalition_member &x, const boost::serialization::version_type ver)
+    {
+      a & x.label;
+      a & x.transport_address;
+      a & x.monero_address_known;
+      a & x.monero_address;
+      a & x.me;
+      a & x.index;
+    }
+
+    template <class Archive>
+    inline void serialize(Archive &a, mms::file_transport_message &x, const boost::serialization::version_type ver)
+    {
+      a & x.sender_address;
+      a & x.iv;
+      a & x.encryption_public_key;
+      a & x.internal_message;
+    }
+
+    template <class Archive>
+    inline void serialize(Archive &a, crypto::chacha_iv &x, const boost::serialization::version_type ver)
+    {
+      a & x.data;
+    }
+
+  }
+}
\ No newline at end of file
diff --git a/src/wallet/message_transporter.cpp b/src/wallet/message_transporter.cpp
new file mode 100644
index 000000000..6394ffcfc
--- /dev/null
+++ b/src/wallet/message_transporter.cpp
@@ -0,0 +1,287 @@
+// Copyright (c) 2014-2018, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
+
+#include "message_transporter.h"
+#include "string_coding.h"
+#include <boost/format.hpp>
+#include "wallet_errors.h"
+#include "net/http_client.h"
+#include "net/net_parse_helpers.h"
+
+#undef MONERO_DEFAULT_LOG_CATEGORY
+#define MONERO_DEFAULT_LOG_CATEGORY "wallet.mms"
+#define PYBITMESSAGE_DEFAULT_API_PORT 8442
+
+namespace mms
+{
+
+namespace bitmessage_rpc
+{
+
+  struct message_info
+  {
+    uint32_t encodingType;
+    std::string toAddress;
+    uint32_t read;
+    std::string msgid;
+    std::string message;
+    std::string fromAddress;
+    std::string receivedTime;
+    std::string subject;
+
+    BEGIN_KV_SERIALIZE_MAP()
+      KV_SERIALIZE(encodingType)
+      KV_SERIALIZE(toAddress)
+      KV_SERIALIZE(read)
+      KV_SERIALIZE(msgid)
+      KV_SERIALIZE(message);
+      KV_SERIALIZE(fromAddress)
+      KV_SERIALIZE(receivedTime)
+      KV_SERIALIZE(subject)
+    END_KV_SERIALIZE_MAP()
+  };
+
+  struct inbox_messages_response
+  {
+    std::vector<message_info> inboxMessages;
+
+    BEGIN_KV_SERIALIZE_MAP()
+      KV_SERIALIZE(inboxMessages)
+    END_KV_SERIALIZE_MAP()
+  };
+
+}
+
+message_transporter::message_transporter()
+{
+  m_run = true;
+}
+
+void message_transporter::set_options(const std::string &bitmessage_address, const std::string &bitmessage_login) {
+  m_bitmessage_url = bitmessage_address;
+  epee::net_utils::http::url_content address_parts{};
+  epee::net_utils::parse_url(m_bitmessage_url, address_parts);
+  if (address_parts.port == 0)
+  {
+    address_parts.port = PYBITMESSAGE_DEFAULT_API_PORT;
+  }
+
+  auto pos = bitmessage_login.find(":");
+  if (pos == std::string::npos)
+  {
+    m_bitmessage_user = bitmessage_login;
+    m_bitmessage_password.clear();
+  }
+  else
+  {
+    m_bitmessage_user = bitmessage_login.substr(0, pos);
+    m_bitmessage_password = bitmessage_login.substr(pos + 1);
+  }
+
+  boost::optional<epee::net_utils::http::login> login{};
+  login.emplace(m_bitmessage_user, m_bitmessage_password);
+  m_http_client.set_server(address_parts.host, std::to_string(address_parts.port), login);
+}
+
+bool message_transporter::receive_messages(const cryptonote::account_public_address &destination_monero_address,
+                                           const std::string &destination_transport_address,
+                                           std::vector<transport_message> &messages)
+{
+  // The message body of the Bitmessage message is basically the transport message, as JSON (and nothing more).
+  // Weeding out other, non-MMS messages is done in a simple way: If it deserializes without error, it's an MMS message
+  // That JSON is Base64-encoded by the MMS because the Monero epee JSON serializer does not escape anything and happily
+  // includes even 0 (NUL) in strings, which might confuse Bitmessage or at least display confusingly in the client.
+  // There is yet another Base64-encoding of course as part of the Bitmessage API for the message body parameter
+  // The Bitmessage API call "getAllInboxMessages" gives back a JSON array with all the messages (despite using
+  // XML-RPC for the calls, and not JSON-RPC ...)
+  m_run.store(true, std::memory_order_relaxed);
+  std::string request;
+  start_xml_rpc_cmd(request, "getAllInboxMessages");
+  end_xml_rpc_cmd(request);
+  std::string answer;
+  post_request(request, answer);
+
+  std::string json = get_str_between_tags(answer, "<string>", "</string>");
+  bitmessage_rpc::inbox_messages_response bitmessage_res;
+  epee::serialization::load_t_from_json(bitmessage_res, json);
+  size_t size = bitmessage_res.inboxMessages.size();
+  messages.clear();
+
+  for (size_t i = 0; i < size; ++i)
+  {
+    if (!m_run.load(std::memory_order_relaxed))
+    {
+      // Stop was called, don't waste time processing any more messages
+      return false;
+    }
+    bitmessage_rpc::message_info message_info = bitmessage_res.inboxMessages[i];
+    transport_message message;
+    bool is_mms_message = false;
+    try
+    {
+      // First Base64-decoding: The message body is Base64 in the Bitmessage API
+      std::string message_body = epee::string_encoding::base64_decode(message_info.message);
+      // Second Base64-decoding: The MMS uses Base64 to hide non-textual data in its JSON from Bitmessage
+      json = epee::string_encoding::base64_decode(message_body);
+      epee::serialization::load_t_from_json(message, json);
+      is_mms_message = true;
+    }
+    catch(const std::exception& e)
+    {
+    }
+    if (is_mms_message)
+    {
+      if (message.destination_monero_address == destination_monero_address)
+      {
+	message.transport_id = message_info.msgid;
+	messages.push_back(message);
+      }
+    }
+  }
+
+  return true;
+}
+
+bool message_transporter::send_message(const transport_message &message)
+{
+  // <toAddress> <fromAddress> <subject> <message> [encodingType [TTL]]
+  std::string request;
+  start_xml_rpc_cmd(request, "sendMessage");
+  add_xml_rpc_string_param(request, message.destination_transport_address);
+  add_xml_rpc_string_param(request, message.source_transport_address);
+  add_xml_rpc_base64_param(request, message.subject);
+  std::string json = epee::serialization::store_t_to_json(message);
+  std::string message_body = epee::string_encoding::base64_encode(json);  // See comment in "receive_message" about reason for (double-)Base64 encoding
+  add_xml_rpc_base64_param(request, message_body);
+  add_xml_rpc_integer_param(request, 2);
+  end_xml_rpc_cmd(request);
+  std::string answer;
+  post_request(request, answer);
+  return true;
+}
+
+bool message_transporter::delete_message(const std::string &transport_id)
+{
+  std::string request;
+  start_xml_rpc_cmd(request, "trashMessage");
+  add_xml_rpc_string_param(request, transport_id);
+  end_xml_rpc_cmd(request);
+  std::string answer;
+  post_request(request, answer);
+  return true;
+}
+
+bool message_transporter::post_request(const std::string &request, std::string &answer)
+{
+  // Somehow things do not work out if one tries to connect "m_http_client" to Bitmessage
+  // and keep it connected over the course of several calls. But with a new connection per
+  // call and disconnecting after the call there is no problem (despite perhaps a small
+  // slowdown)
+  epee::net_utils::http::fields_list additional_params;
+
+  // Basic access authentication according to RFC 7617 (which the epee HTTP classes do not seem to support?)
+  std::string user_password(m_bitmessage_user + ":" + m_bitmessage_password);
+  std::string auth_string = epee::string_encoding::base64_encode(user_password);
+  auth_string.insert(0, "Basic ");
+  additional_params.push_back(std::make_pair("Authorization", auth_string));
+
+  additional_params.push_back(std::make_pair("Content-Type", "application/xml; charset=utf-8"));
+  const epee::net_utils::http::http_response_info* response = NULL;
+  std::chrono::milliseconds timeout = std::chrono::seconds(15);
+  bool r = m_http_client.invoke("/", "POST", request, timeout, std::addressof(response), std::move(additional_params));
+  if (r)
+  {
+    answer = response->m_body;
+  }
+  else
+  {
+    LOG_ERROR("POST request to Bitmessage failed: " << request.substr(0, 300));
+    THROW_WALLET_EXCEPTION(tools::error::no_connection_to_bitmessage, m_bitmessage_url);
+  }
+  m_http_client.disconnect();  // see comment above
+  std::string string_value = get_str_between_tags(answer, "<string>", "</string>");
+  if ((string_value.find("API Error") == 0) || (string_value.find("RPC ") == 0))
+  {
+    THROW_WALLET_EXCEPTION(tools::error::bitmessage_api_error, string_value);
+  }
+
+  return r;
+}
+
+// Pick some string between two delimiters
+// When parsing the XML returned by PyBitmessage, don't bother to fully parse it but as a little hack rely on the
+// fact that e.g. a single string returned will be, however deeply nested in "<params><param><value>...", delivered
+// between the very first "<string>" and "</string>" tags to be found in the XML
+std::string message_transporter::get_str_between_tags(const std::string &s, const std::string &start_delim, const std::string &stop_delim)
+{
+  size_t first_delim_pos = s.find(start_delim);
+  if (first_delim_pos != std::string::npos)
+  {
+    size_t end_pos_of_first_delim = first_delim_pos + start_delim.length();
+    size_t last_delim_pos = s.find(stop_delim);
+    if (last_delim_pos != std::string::npos)
+    {
+      return s.substr(end_pos_of_first_delim, last_delim_pos - end_pos_of_first_delim);
+    }
+  }
+  return std::string();
+}
+
+void message_transporter::start_xml_rpc_cmd(std::string &xml, const std::string &method_name)
+{
+  xml = (boost::format("<?xml version=\"1.0\"?><methodCall><methodName>%s</methodName><params>") % method_name).str();
+}
+
+void message_transporter::add_xml_rpc_string_param(std::string &xml, const std::string &param)
+{
+  xml += (boost::format("<param><value><string>%s</string></value></param>") % param).str();
+}
+
+void message_transporter::add_xml_rpc_base64_param(std::string &xml, const std::string &param)
+{
+  // Bitmessage expects some arguments Base64-encoded, but it wants them as parameters of type "string", not "base64" that is also part of XML-RPC
+  std::string encoded_param = epee::string_encoding::base64_encode(param);
+  xml += (boost::format("<param><value><string>%s</string></value></param>") % encoded_param).str();
+}
+
+void message_transporter::add_xml_rpc_integer_param(std::string &xml, const int32_t &param)
+{
+  xml += (boost::format("<param><value><int>%i</int></value></param>") % param).str();
+}
+
+void message_transporter::end_xml_rpc_cmd(std::string &xml)
+{
+  xml += "</params></methodCall>";
+}
+
+
+
+}
+
diff --git a/src/wallet/message_transporter.h b/src/wallet/message_transporter.h
new file mode 100644
index 000000000..0de2bbd78
--- /dev/null
+++ b/src/wallet/message_transporter.h
@@ -0,0 +1,113 @@
+// Copyright (c) 2014-2018, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
+
+#pragma once
+#include "serialization/keyvalue_serialization.h"
+#include "cryptonote_basic/cryptonote_basic.h"
+#include "cryptonote_basic/cryptonote_boost_serialization.h"
+#include "cryptonote_basic/account_boost_serialization.h"
+#include "cryptonote_basic/cryptonote_basic.h"
+#include "net/http_server_impl_base.h"
+#include "net/http_client.h"
+#include "common/util.h"
+#include "serialization/keyvalue_serialization.h"
+
+#define PYBITMESSAGE_API_PORT 8442
+
+namespace mms
+{
+
+struct transport_message
+{
+  cryptonote::account_public_address source_monero_address;
+  std::string source_transport_address;
+  cryptonote::account_public_address destination_monero_address;
+  std::string destination_transport_address;
+  crypto::chacha_iv iv;
+  crypto::public_key encryption_public_key;
+  uint64_t timestamp;
+  uint32_t type;
+  std::string subject;
+  std::string content;
+  crypto::hash hash;
+  crypto::signature signature;
+  uint32_t round;
+  uint32_t signature_count;
+  std::string transport_id;
+
+  BEGIN_KV_SERIALIZE_MAP()
+    KV_SERIALIZE(source_monero_address)
+    KV_SERIALIZE(source_transport_address)
+    KV_SERIALIZE(destination_monero_address)
+    KV_SERIALIZE(destination_transport_address)
+    KV_SERIALIZE_VAL_POD_AS_BLOB_FORCE(iv)
+    KV_SERIALIZE_VAL_POD_AS_BLOB_FORCE(encryption_public_key)
+    KV_SERIALIZE(timestamp)
+    KV_SERIALIZE(type)
+    KV_SERIALIZE(subject)
+    KV_SERIALIZE(content)
+    KV_SERIALIZE_VAL_POD_AS_BLOB_FORCE(hash)
+    KV_SERIALIZE_VAL_POD_AS_BLOB_FORCE(signature)
+    KV_SERIALIZE(round)
+    KV_SERIALIZE(signature_count)
+    KV_SERIALIZE(transport_id)
+  END_KV_SERIALIZE_MAP()
+};
+
+class message_transporter {
+public:
+  message_transporter();
+  void set_options(const std::string &bitmessage_address, const std::string &bitmessage_login);
+  bool send_message(const transport_message &message);
+  bool receive_messages(const cryptonote::account_public_address &destination_monero_address,
+                        const std::string &destination_transport_address,
+                        std::vector<transport_message> &messages);
+  bool delete_message(const std::string &transport_id);
+  void stop() { m_run.store(false, std::memory_order_relaxed); }
+
+private:
+  epee::net_utils::http::http_simple_client m_http_client;
+  std::string m_bitmessage_url;
+  std::string m_bitmessage_user;
+  std::string m_bitmessage_password;
+  std::atomic<bool> m_run;
+
+  bool post_request(const std::string &request, std::string &answer);
+  std::string get_str_between_tags(const std::string &s, const std::string &start_delim, const std::string &stop_delim);
+
+  void start_xml_rpc_cmd(std::string &xml, const std::string &method_name);
+  void add_xml_rpc_string_param(std::string &xml, const std::string &param);
+  void add_xml_rpc_base64_param(std::string &xml, const std::string &param);
+  void add_xml_rpc_integer_param(std::string &xml, const int32_t &param);
+  void end_xml_rpc_cmd(std::string &xml);
+
+};
+
+}
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index 4c4ee8bf3..1bb9f52bc 100755
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -153,7 +153,7 @@ struct options {
   };
 };
 
-void do_prepare_file_names(const std::string& file_path, std::string& keys_file, std::string& wallet_file)
+void do_prepare_file_names(const std::string& file_path, std::string& keys_file, std::string& wallet_file, std::string &mms_file)
 {
   keys_file = file_path;
   wallet_file = file_path;
@@ -165,6 +165,7 @@ void do_prepare_file_names(const std::string& file_path, std::string& keys_file,
   {//provided wallet file name
     keys_file += ".keys";
   }
+  mms_file = file_path + ".mms";
 }
 
 uint64_t calculate_fee(uint64_t fee_per_kb, size_t bytes, uint64_t fee_multiplier)
@@ -230,6 +231,7 @@ std::unique_ptr<tools::wallet2> make_basic(const boost::program_options::variabl
   wallet->init(std::move(daemon_address), std::move(login));
   boost::filesystem::path ringdb_path = command_line::get_arg(vm, opts.shared_ringdb_dir);
   wallet->set_ring_database(ringdb_path.string());
+  wallet->get_message_store().set_options(vm);
   return wallet;
 }
 
@@ -676,6 +678,8 @@ wallet2::wallet2(network_type nettype, bool restricted):
   m_light_wallet_connected(false),
   m_light_wallet_balance(0),
   m_light_wallet_unlocked_balance(0),
+  m_original_keys_available(false),
+  m_message_store(),
   m_key_on_device(false),
   m_ring_history_saved(false),
   m_ringdb()
@@ -709,6 +713,7 @@ void wallet2::init_options(boost::program_options::options_description& desc_par
   command_line::add_arg(desc_params, opts.stagenet);
   command_line::add_arg(desc_params, opts.restricted);
   command_line::add_arg(desc_params, opts.shared_ringdb_dir);
+  mms::message_store::init_options(desc_params);
 }
 
 std::unique_ptr<wallet2> wallet2::make_from_json(const boost::program_options::variables_map& vm, const std::string& json_file, const std::function<boost::optional<tools::password_container>(const char *, bool)> &password_prompter)
@@ -2581,6 +2586,7 @@ bool wallet2::store_keys(const std::string& keys_file_name, const epee::wipeable
   rapidjson::Document json;
   json.SetObject();
   rapidjson::Value value(rapidjson::kStringType);
+
   value.SetString(account_data.c_str(), account_data.length());
   json.AddMember("key_data", value, json.GetAllocator());
   if (!seed_language.empty())
@@ -2683,6 +2689,22 @@ bool wallet2::store_keys(const std::string& keys_file_name, const epee::wipeable
   value2.SetUint(m_subaddress_lookahead_minor);
   json.AddMember("subaddress_lookahead_minor", value2, json.GetAllocator());
 
+  value2.SetInt(m_original_keys_available ? 1 : 0);
+  json.AddMember("original_keys_available", value2, json.GetAllocator());
+
+  std::string original_address;
+  std::string original_view_secret_key;
+  if (m_original_keys_available)
+  {
+    original_address = get_account_address_as_str(m_nettype, false, m_original_address);
+    value.SetString(original_address.c_str(), original_address.length());
+    json.AddMember("original_address", value, json.GetAllocator());
+
+    original_view_secret_key = epee::string_tools::pod_to_hex(m_original_view_secret_key);
+    value.SetString(original_view_secret_key.c_str(), original_view_secret_key.length());
+    json.AddMember("original_view_secret_key", value, json.GetAllocator());
+  }
+
   // Serialize the JSON object
   rapidjson::StringBuffer buffer;
   rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
@@ -2758,6 +2780,7 @@ bool wallet2::load_keys(const std::string& keys_file_name, const epee::wipeable_
     m_segregation_height = 0;
     m_subaddress_lookahead_major = SUBADDRESS_LOOKAHEAD_MAJOR;
     m_subaddress_lookahead_minor = SUBADDRESS_LOOKAHEAD_MINOR;
+    m_original_keys_available = false;
     m_key_on_device = false;
   }
   else if(json.IsObject())
@@ -2884,6 +2907,44 @@ bool wallet2::load_keys(const std::string& keys_file_name, const epee::wipeable_
     m_subaddress_lookahead_major = field_subaddress_lookahead_major;
     GET_FIELD_FROM_JSON_RETURN_ON_ERROR(json, subaddress_lookahead_minor, uint32_t, Uint, false, SUBADDRESS_LOOKAHEAD_MINOR);
     m_subaddress_lookahead_minor = field_subaddress_lookahead_minor;
+
+    if (json.HasMember("original_keys_available"))
+    {
+      GET_FIELD_FROM_JSON_RETURN_ON_ERROR(json, original_keys_available, int, Int, false, false);
+      m_original_keys_available = field_original_keys_available;
+      if (m_original_keys_available)
+      {
+	GET_FIELD_FROM_JSON_RETURN_ON_ERROR(json, original_address, std::string, String, false, std::string());
+	if (!field_original_address_found)
+	{
+	  LOG_ERROR("Field original_address not found in JSON");
+	  return false;
+	}
+	address_parse_info info;
+	bool ok = get_account_address_from_str(info, m_nettype, field_original_address);
+        if (!ok)
+	{
+	  LOG_ERROR("Failed to parse original_address from JSON");
+	  return false;
+	}
+	m_original_address = info.address;
+	GET_FIELD_FROM_JSON_RETURN_ON_ERROR(json, original_view_secret_key, std::string, String, false, std::string());
+	if (!field_original_view_secret_key_found)
+	{
+	  LOG_ERROR("Field original_view_secret_key not found in JSON");
+	  return false;
+	}
+	ok = epee::string_tools::hex_to_pod(field_original_view_secret_key, m_original_view_secret_key);
+	if (!ok)
+	{
+	  LOG_ERROR("Failed to parse original_view_secret_key from JSON");
+	}
+      }
+    }
+    else
+    {
+      m_original_keys_available = false;
+    }
   }
   else
   {
@@ -3051,6 +3112,10 @@ void wallet2::generate(const std::string& wallet_, const epee::wipeable_string&
   m_multisig_signers = multisig_signers;
   m_key_on_device = false;
 
+  // Not possible to restore a multisig wallet that is able to activate the MMS
+  // (because the original keys are not (yet) part of the restore info)
+  m_original_keys_available = false;
+
   if (!wallet_.empty())
   {
     bool r = store_keys(m_keys_file, password, false);
@@ -3101,6 +3166,7 @@ crypto::secret_key wallet2::generate(const std::string& wallet_, const epee::wip
   m_multisig = false;
   m_multisig_threshold = 0;
   m_multisig_signers.clear();
+  m_original_keys_available = false;
   m_key_on_device = false;
 
   // calculate a starting refresh height
@@ -3199,6 +3265,7 @@ void wallet2::generate(const std::string& wallet_, const epee::wipeable_string&
   m_multisig = false;
   m_multisig_threshold = 0;
   m_multisig_signers.clear();
+  m_original_keys_available = false;
   m_key_on_device = false;
 
   if (!wallet_.empty())
@@ -3249,6 +3316,7 @@ void wallet2::generate(const std::string& wallet_, const epee::wipeable_string&
   m_multisig = false;
   m_multisig_threshold = 0;
   m_multisig_signers.clear();
+  m_original_keys_available = false;
   m_key_on_device = false;
 
   if (!wallet_.empty())
@@ -3295,6 +3363,7 @@ void wallet2::restore(const std::string& wallet_, const epee::wipeable_string& p
   m_multisig = false;
   m_multisig_threshold = 0;
   m_multisig_signers.clear();
+  m_original_keys_available = false;
 
   if (!wallet_.empty()) {
     bool r = store_keys(m_keys_file, password, false);
@@ -3369,6 +3438,15 @@ std::string wallet2::make_multisig(const epee::wipeable_string &password,
     CHECK_AND_ASSERT_THROW_MES(false, "Unsupported threshold case");
   }
 
+  if (!m_original_keys_available)
+  {
+    // Save the original i.e. non-multisig keys so the MMS can continue to use them to encrypt and decrypt messages
+    // (making a wallet multisig overwrites those keys, see account_base::make_multisig)
+    m_original_address = m_account.get_keys().m_account_address;
+    m_original_view_secret_key = m_account.get_keys().m_view_secret_key;
+    m_original_keys_available = true;
+  }
+
   // the multisig view key is shared by all, make one all can derive
   MINFO("Creating view key...");
   crypto::secret_key view_skey = cryptonote::generate_multisig_view_secret_key(get_account().get_keys().m_view_secret_key, view_keys);
@@ -3696,8 +3774,8 @@ void wallet2::write_watch_only_wallet(const std::string& wallet_name, const epee
 //----------------------------------------------------------------------------------------------------
 void wallet2::wallet_exists(const std::string& file_path, bool& keys_file_exists, bool& wallet_file_exists)
 {
-  std::string keys_file, wallet_file;
-  do_prepare_file_names(file_path, keys_file, wallet_file);
+  std::string keys_file, wallet_file, mms_file;
+  do_prepare_file_names(file_path, keys_file, wallet_file, mms_file);
 
   boost::system::error_code ignore;
   keys_file_exists = boost::filesystem::exists(keys_file, ignore);
@@ -3751,7 +3829,7 @@ bool wallet2::parse_payment_id(const std::string& payment_id_str, crypto::hash&
 //----------------------------------------------------------------------------------------------------
 bool wallet2::prepare_file_names(const std::string& file_path)
 {
-  do_prepare_file_names(file_path, m_keys_file, m_wallet_file);
+  do_prepare_file_names(file_path, m_keys_file, m_wallet_file, m_mms_file);
   return true;
 }
 //----------------------------------------------------------------------------------------------------
@@ -3922,6 +4000,8 @@ void wallet2::load(const std::string& wallet_, const epee::wipeable_string& pass
   {
     MERROR("Failed to save rings, will try again next time");
   }
+
+  m_message_store.read_from_file(get_multisig_wallet_state(), m_mms_file);
 }
 //----------------------------------------------------------------------------------------------------
 void wallet2::trim_hashchain()
@@ -4029,6 +4109,7 @@ void wallet2::store_to(const std::string &path, const epee::wipeable_string &pas
   const std::string old_file = m_wallet_file;
   const std::string old_keys_file = m_keys_file;
   const std::string old_address_file = m_wallet_file + ".address.txt";
+  const std::string old_mms_file = m_mms_file;
 
   // save keys to the new file
   // if we here, main wallet file is saved and we only need to save keys and address files
@@ -4058,6 +4139,14 @@ void wallet2::store_to(const std::string &path, const epee::wipeable_string &pas
     if (!r) {
       LOG_ERROR("error removing file: " << old_address_file);
     }
+    // remove old message store file
+    if (boost::filesystem::exists(old_mms_file))
+      {
+      r = boost::filesystem::remove(old_mms_file);
+      if (!r) {
+	LOG_ERROR("error removing file: " << old_mms_file);
+      }
+    }
   } else {
     // save to new file
 #ifdef WIN32
@@ -4083,6 +4172,14 @@ void wallet2::store_to(const std::string &path, const epee::wipeable_string &pas
     std::error_code e = tools::replace_file(new_file, m_wallet_file);
     THROW_WALLET_EXCEPTION_IF(e, error::file_save_error, m_wallet_file, e);
   }
+
+  if (m_message_store.get_active())
+  {
+    // While the "m_message_store" object of course always exist, a file for the message
+    // store should only exist if the MMS is really active
+    m_message_store.write_to_file(get_multisig_wallet_state(), m_mms_file);
+  }
+
 }
 //----------------------------------------------------------------------------------------------------
 uint64_t wallet2::balance(uint32_t index_major) const
@@ -10561,4 +10658,28 @@ void wallet2::generate_genesis(cryptonote::block& b) const {
     cryptonote::generate_genesis_block(b, config::GENESIS_TX, config::GENESIS_NONCE);
   }
 }
+//----------------------------------------------------------------------------------------------------
+mms::multisig_wallet_state wallet2::get_multisig_wallet_state()
+{
+  mms::multisig_wallet_state state;
+  state.nettype = m_nettype;
+  state.multisig = multisig(&state.multisig_is_ready);
+  state.has_multisig_partial_key_images = has_multisig_partial_key_images();
+  state.num_transfer_details = m_transfers.size();
+  if (state.multisig)
+  {
+    THROW_WALLET_EXCEPTION_IF(!m_original_keys_available, error::wallet_internal_error, "MMS use not possible because own original Monero address not available");
+    state.address = m_original_address;
+    state.view_secret_key = m_original_view_secret_key;
+  }
+  else
+  {
+    state.address = m_account.get_keys().m_account_address;
+    state.view_secret_key = m_account.get_keys().m_view_secret_key;
+  }
+  state.mms_file=m_mms_file;
+  return state;
+}
+
+
 }
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index f2e861f18..1d7a2b155 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -58,6 +58,7 @@
 #include "wallet_errors.h"
 #include "common/password.h"
 #include "node_rpc_proxy.h"
+#include "message_store.h"
 
 #undef MONERO_DEFAULT_LOG_CATEGORY
 #define MONERO_DEFAULT_LOG_CATEGORY "wallet.wallet2"
@@ -454,6 +455,7 @@ namespace tools
 
     typedef std::tuple<uint64_t, crypto::public_key, rct::key> get_outs_entry;
 
+
     /*!
      * \brief  Generates a wallet or restores one.
      * \param  wallet_              Name of wallet file
@@ -593,7 +595,7 @@ namespace tools
     bool init(std::string daemon_address = "http://localhost:8080",
       boost::optional<epee::net_utils::http::login> daemon_login = boost::none, uint64_t upper_transaction_size_limit = 0, bool ssl = false);
 
-    void stop() { m_run.store(false, std::memory_order_relaxed); }
+    void stop() { m_run.store(false, std::memory_order_relaxed); m_message_store.stop(); }
 
     i_wallet2_callback* callback() const { return m_callback; }
     void callback(i_wallet2_callback* callback) { m_callback = callback; }
@@ -1077,6 +1079,10 @@ namespace tools
     bool unblackball_output(const crypto::public_key &output);
     bool is_output_blackballed(const crypto::public_key &output) const;
 
+    // MMS -------------------------------------------------------------------------------------------------
+    mms::message_store& get_message_store() { return m_message_store; };
+    mms::multisig_wallet_state get_multisig_wallet_state();
+
   private:
     /*!
      * \brief  Stores wallet information to wallet file.
@@ -1148,6 +1154,7 @@ namespace tools
     std::string m_daemon_address;
     std::string m_wallet_file;
     std::string m_keys_file;
+    std::string m_mms_file;
     epee::net_utils::http::http_simple_client m_http_client;
     hashchain m_blockchain;
     std::atomic<uint64_t> m_local_bc_height; //temporary workaround
@@ -1232,6 +1239,11 @@ namespace tools
     std::string m_ring_database;
     bool m_ring_history_saved;
     std::unique_ptr<ringdb> m_ringdb;
+
+    mms::message_store m_message_store;
+    bool m_original_keys_available;
+    cryptonote::account_public_address m_original_address;
+    crypto::secret_key m_original_view_secret_key;
   };
 }
 BOOST_CLASS_VERSION(tools::wallet2, 24)
diff --git a/src/wallet/wallet_errors.h b/src/wallet/wallet_errors.h
index 214d51cde..46dcc1ddd 100644
--- a/src/wallet/wallet_errors.h
+++ b/src/wallet/wallet_errors.h
@@ -784,6 +784,31 @@ namespace tools
       std::string m_wallet_file;
     };
     //----------------------------------------------------------------------------------------------------
+    struct mms_error : public wallet_logic_error
+    {
+    protected:
+      explicit mms_error(std::string&& loc, const std::string& message)
+        : wallet_logic_error(std::move(loc), message)
+      {
+      }
+    };
+    //----------------------------------------------------------------------------------------------------
+    struct no_connection_to_bitmessage : public mms_error
+    {
+      explicit no_connection_to_bitmessage(std::string&& loc, const std::string& address)
+        : mms_error(std::move(loc), "no connection to PyBitmessage at address " + address)
+      {
+      }
+    };
+    //----------------------------------------------------------------------------------------------------
+    struct bitmessage_api_error : public mms_error
+    {
+      explicit bitmessage_api_error(std::string&& loc, const std::string& error_string)
+        : mms_error(std::move(loc), "PyBitmessage returned " + error_string)
+      {
+      }
+    };
+    //----------------------------------------------------------------------------------------------------
 
 #if !defined(_MSC_VER)