wallet: support for multisig seeds

They are hex rather than words, because they are a lot longer
than "normal" seeds, as they have to embed a lot more information

src/simplewallet/simplewallet.cpp

@@ -121,6 +121,7 @@ namespace
   const command_line::arg_descriptor<std::string> arg_mnemonic_language = {"mnemonic-language", sw::tr("Language for mnemonic"), ""};
   const command_line::arg_descriptor<std::string> arg_electrum_seed = {"electrum-seed", sw::tr("Specify Electrum seed for wallet recovery/creation"), ""};
   const command_line::arg_descriptor<bool> arg_restore_deterministic_wallet = {"restore-deterministic-wallet", sw::tr("Recover wallet using Electrum-style mnemonic seed"), false};
+  const command_line::arg_descriptor<bool> arg_restore_multisig_wallet = {"restore-multisig-wallet", sw::tr("Recover multisig wallet using Electrum-style mnemonic seed"), false};
   const command_line::arg_descriptor<bool> arg_non_deterministic = {"non-deterministic", sw::tr("Create non-deterministic view and spend keys"), false};
   const command_line::arg_descriptor<bool> arg_trusted_daemon = {"trusted-daemon", sw::tr("Enable commands which rely on a trusted daemon"), false};
   const command_line::arg_descriptor<bool> arg_allow_mismatched_daemon_version = {"allow-mismatched-daemon-version", sw::tr("Allow communicating with a daemon that uses a different RPC version"), false};
@@ -516,48 +517,55 @@ bool simple_wallet::spendkey(const std::vector<std::string> &args/* = std::vecto
 bool simple_wallet::print_seed(bool encrypted)
 {
   bool success =  false;
-  std::string electrum_words;
+  std::string seed;
+  bool ready, multisig;
 
-  if (m_wallet->multisig())
-  {
-    fail_msg_writer() << tr("wallet is multisig and has no seed");
-    return true;
-  }
   if (m_wallet->watch_only())
   {
     fail_msg_writer() << tr("wallet is watch-only and has no seed");
     return true;
   }
   if (m_wallet->ask_password() && !get_and_verify_password()) { return true; }
-  if (m_wallet->is_deterministic())
+
+  multisig = m_wallet->multisig(&ready);
+  if (multisig)
   {
-    if (m_wallet->get_seed_language().empty())
+    if (!ready)
     {
-      std::string mnemonic_language = get_mnemonic_language();
+      fail_msg_writer() << tr("wallet is multisig but not yet finalized");
-      if (mnemonic_language.empty())
+      return true;
+    }
+  }
+  else if (!m_wallet->is_deterministic())
+  {
+    fail_msg_writer() << tr("wallet is non-deterministic and has no seed");
     return true;
-      m_wallet->set_seed_language(mnemonic_language);
   }
 
   epee::wipeable_string seed_pass;
   if (encrypted)
   {
+#ifdef HAVE_READLINE
+    rdln::suspend_readline pause_readline;
+#endif
     auto pwd_container = tools::password_container::prompt(true, tr("Enter optional seed encryption passphrase, empty to see raw seed"));
     if (std::cin.eof() || !pwd_container)
       return true;
     seed_pass = pwd_container->password();
   }
 
-    success = m_wallet->get_seed(electrum_words, seed_pass);
+  if (multisig)
-  }
+    success = m_wallet->get_multisig_seed(seed, seed_pass);
+  else if (m_wallet->is_deterministic())
+    success = m_wallet->get_seed(seed, seed_pass);
 
   if (success) 
   {
-    print_seed(electrum_words);
+    print_seed(seed);
   }
   else
   {
-    fail_msg_writer() << tr("wallet is non-deterministic and has no seed");
+    fail_msg_writer() << tr("Failed to retrieve seed");
   }
   return true;
 }
@@ -1972,6 +1980,8 @@ static bool might_be_partial_seed(std::string words)
 //----------------------------------------------------------------------------------------------------
 bool simple_wallet::init(const boost::program_options::variables_map& vm)
 {
+  std::string multisig_keys;
+
   if (!handle_command_line(vm))
     return false;
 
@@ -1989,20 +1999,37 @@ bool simple_wallet::init(const boost::program_options::variables_map& vm)
   {
     std::string old_language;
     // check for recover flag.  if present, require electrum word list (only recovery option for now).
-    if (m_restore_deterministic_wallet)
+    if (m_restore_deterministic_wallet || m_restore_multisig_wallet)
     {
       if (m_non_deterministic)
       {
-        fail_msg_writer() << tr("can't specify both --restore-deterministic-wallet and --non-deterministic");
+        fail_msg_writer() << tr("can't specify both --restore-deterministic-wallet or --restore-multisig-wallet and --non-deterministic");
         return false;
       }
       if (!m_wallet_file.empty())
       {
+        if (m_restore_multisig_wallet)
+          fail_msg_writer() << tr("--restore-multisig-wallet uses --generate-new-wallet, not --wallet-file");
+        else
           fail_msg_writer() << tr("--restore-deterministic-wallet uses --generate-new-wallet, not --wallet-file");
         return false;
       }
 
       if (m_electrum_seed.empty())
+      {
+        if (m_restore_multisig_wallet)
+        {
+            const char *prompt = "Specify multisig seed: ";
+            m_electrum_seed = input_line(prompt);
+            if (std::cin.eof())
+              return false;
+            if (m_electrum_seed.empty())
+            {
+              fail_msg_writer() << tr("specify a recovery parameter with the --electrum-seed=\"multisig seed here\"");
+              return false;
+            }
+        }
+        else
         {
           m_electrum_seed = "";
           do
@@ -2019,20 +2046,45 @@ bool simple_wallet::init(const boost::program_options::variables_map& vm)
             m_electrum_seed += electrum_seed + " ";
           } while (might_be_partial_seed(m_electrum_seed));
         }
+      }
 
+      if (m_restore_multisig_wallet)
+      {
+        if (!epee::string_tools::parse_hexstr_to_binbuff(m_electrum_seed, multisig_keys))
+        {
+          fail_msg_writer() << tr("Multisig seed failed verification");
+          return false;
+        }
+      }
+      else
+      {
         if (!crypto::ElectrumWords::words_to_bytes(m_electrum_seed, m_recovery_key, old_language))
         {
           fail_msg_writer() << tr("Electrum-style word list failed verification");
           return false;
         }
+      }
 
+#ifdef HAVE_READLINE
+    rdln::suspend_readline pause_readline;
+#endif
       auto pwd_container = tools::password_container::prompt(false, tr("Enter seed encryption passphrase, empty if none"));
       if (std::cin.eof() || !pwd_container)
         return false;
       epee::wipeable_string seed_pass = pwd_container->password();
       if (!seed_pass.empty())
+      {
+        if (m_restore_multisig_wallet)
+        {
+          crypto::secret_key key;
+          crypto::cn_slow_hash(seed_pass.data(), seed_pass.size(), (crypto::hash&)key);
+          sc_reduce32((unsigned char*)key.data);
+          multisig_keys = m_wallet->decrypt(multisig_keys, key, true);
+        }
+        else
           m_recovery_key = cryptonote::decrypt_key(m_recovery_key, seed_pass);
       }
+    }
     if (!m_generate_from_view_key.empty())
     {
       m_wallet_file = m_generate_from_view_key;
@@ -2342,7 +2394,11 @@ bool simple_wallet::init(const boost::program_options::variables_map& vm)
         return false;
       }
       m_wallet_file = m_generate_new;
-      bool r = new_wallet(vm, m_recovery_key, m_restore_deterministic_wallet, m_non_deterministic, old_language);
+      bool r;
+      if (m_restore_multisig_wallet)
+        r = new_wallet(vm, multisig_keys, old_language);
+      else
+        r = new_wallet(vm, m_recovery_key, m_restore_deterministic_wallet, m_non_deterministic, old_language);
       CHECK_AND_ASSERT_MES(r, false, tr("account creation failed"));
     }
     if (!m_restore_height && m_restoring)
@@ -2473,6 +2529,7 @@ bool simple_wallet::handle_command_line(const boost::program_options::variables_
   m_mnemonic_language             = command_line::get_arg(vm, arg_mnemonic_language);
   m_electrum_seed                 = command_line::get_arg(vm, arg_electrum_seed);
   m_restore_deterministic_wallet  = command_line::get_arg(vm, arg_restore_deterministic_wallet);
+  m_restore_multisig_wallet       = command_line::get_arg(vm, arg_restore_multisig_wallet);
   m_non_deterministic             = command_line::get_arg(vm, arg_non_deterministic);
   m_trusted_daemon                = command_line::get_arg(vm, arg_trusted_daemon);
   m_allow_mismatched_daemon_version = command_line::get_arg(vm, arg_allow_mismatched_daemon_version);
@@ -2483,7 +2540,8 @@ bool simple_wallet::handle_command_line(const boost::program_options::variables_
                                     !m_generate_from_keys.empty() ||
                                     !m_generate_from_multisig_keys.empty() ||
                                     !m_generate_from_json.empty() ||
-                                    m_restore_deterministic_wallet;
+                                    m_restore_deterministic_wallet ||
+                                    m_restore_multisig_wallet;
 
   return true;
 }
@@ -2680,6 +2738,49 @@ bool simple_wallet::new_wallet(const boost::program_options::variables_map& vm,
   }
 
 
+  return true;
+}
+//----------------------------------------------------------------------------------------------------
+bool simple_wallet::new_wallet(const boost::program_options::variables_map& vm,
+    const std::string &multisig_keys, const std::string &old_language)
+{
+  auto rc = tools::wallet2::make_new(vm, password_prompter);
+  m_wallet = std::move(rc.first);
+  if (!m_wallet)
+  {
+    return false;
+  }
+
+  std::string mnemonic_language = old_language;
+
+  std::vector<std::string> language_list;
+  crypto::ElectrumWords::get_language_list(language_list);
+  if (mnemonic_language.empty() && std::find(language_list.begin(), language_list.end(), m_mnemonic_language) != language_list.end())
+  {
+    mnemonic_language = m_mnemonic_language;
+  }
+
+  m_wallet->set_seed_language(mnemonic_language);
+
+  try
+  {
+    m_wallet->generate(m_wallet_file, std::move(rc.second).password(), multisig_keys);
+    bool ready;
+    uint32_t threshold, total;
+    if (!m_wallet->multisig(&ready, &threshold, &total) || !ready)
+    {
+      fail_msg_writer() << tr("failed to generate new mutlisig wallet");
+      return false;
+    }
+    message_writer(console_color_white, true) << boost::format(tr("Generated new %u/%u multisig wallet: ")) % threshold % total
+      << m_wallet->get_account().get_public_address_str(m_wallet->testnet());
+  }
+  catch (const std::exception& e)
+  {
+    fail_msg_writer() << tr("failed to generate new wallet: ") << e.what();
+    return false;
+  }
+
   return true;
 }
 //----------------------------------------------------------------------------------------------------
@@ -6425,6 +6526,7 @@ int main(int argc, char* argv[])
   command_line::add_arg(desc_params, arg_command);
 
   command_line::add_arg(desc_params, arg_restore_deterministic_wallet );
+  command_line::add_arg(desc_params, arg_restore_multisig_wallet );
   command_line::add_arg(desc_params, arg_non_deterministic );
   command_line::add_arg(desc_params, arg_electrum_seed );
   command_line::add_arg(desc_params, arg_trusted_daemon);

src/simplewallet/simplewallet.h

@@ -92,6 +92,8 @@ namespace cryptonote
         bool recover, bool two_random, const std::string &old_language);
     bool new_wallet(const boost::program_options::variables_map& vm, const cryptonote::account_public_address& address,
         const boost::optional<crypto::secret_key>& spendkey, const crypto::secret_key& viewkey);
+    bool new_wallet(const boost::program_options::variables_map& vm,
+        const std::string &multisig_keys, const std::string &old_language);
     bool open_wallet(const boost::program_options::variables_map& vm);
     bool close_wallet();
 
@@ -305,6 +307,7 @@ namespace cryptonote
 
     crypto::secret_key m_recovery_key;  // recovery key (used as random for wallet gen)
     bool m_restore_deterministic_wallet;  // recover flag
+    bool m_restore_multisig_wallet;  // recover flag
     bool m_non_deterministic;  // old 2-random generation
     bool m_trusted_daemon;
     bool m_allow_mismatched_daemon_version;

src/wallet/wallet2.cpp

@@ -714,6 +714,70 @@ bool wallet2::get_seed(std::string& electrum_words, const epee::wipeable_string
 
   return true;
 }
+//----------------------------------------------------------------------------------------------------
+bool wallet2::get_multisig_seed(std::string& seed, const epee::wipeable_string &passphrase, bool raw) const
+{
+  bool ready;
+  uint32_t threshold, total;
+  if (!multisig(&ready, &threshold, &total))
+  {
+    std::cout << "This is not a multisig wallet" << std::endl;
+    return false;
+  }
+  if (!ready)
+  {
+    std::cout << "This multisig wallet is not yet finalized" << std::endl;
+    return false;
+  }
+  if (!raw && seed_language.empty())
+  {
+    std::cout << "seed_language not set" << std::endl;
+    return false;
+  }
+
+  crypto::secret_key skey;
+  crypto::public_key pkey;
+  const account_keys &keys = get_account().get_keys();
+  std::string data;
+  data.append((const char*)&threshold, sizeof(uint32_t));
+  data.append((const char*)&total, sizeof(uint32_t));
+  skey = keys.m_spend_secret_key;
+  data.append((const char*)&skey, sizeof(skey));
+  pkey = keys.m_account_address.m_spend_public_key;
+  data.append((const char*)&pkey, sizeof(pkey));
+  skey = keys.m_view_secret_key;
+  data.append((const char*)&skey, sizeof(skey));
+  pkey = keys.m_account_address.m_view_public_key;
+  data.append((const char*)&pkey, sizeof(pkey));
+  for (const auto &skey: keys.m_multisig_keys)
+    data.append((const char*)&skey, sizeof(skey));
+  for (const auto &signer: m_multisig_signers)
+    data.append((const char*)&signer, sizeof(signer));
+
+  if (!passphrase.empty())
+  {
+    crypto::secret_key key;
+    crypto::cn_slow_hash(passphrase.data(), passphrase.size(), (crypto::hash&)key);
+    sc_reduce32((unsigned char*)key.data);
+    data = encrypt(data, key, true);
+  }
+
+  if (raw)
+  {
+    seed = epee::string_tools::buff_to_hex_nodelimer(data);
+  }
+  else
+  {
+    if (!crypto::ElectrumWords::bytes_to_words(data.data(), data.size(), seed, seed_language))
+    {
+      std::cout << "Failed to encode seed";
+      return false;
+    }
+  }
+
+  return true;
+}
+//----------------------------------------------------------------------------------------------------
 /*!
  * \brief Gets the seed language
  */
@@ -2619,6 +2683,97 @@ bool wallet2::verify_password(const std::string& keys_file_name, const epee::wip
   return r;
 }
 
+/*!
+ * \brief  Generates a wallet or restores one.
+ * \param  wallet_        Name of wallet file
+ * \param  password       Password of wallet file
+ * \param  multisig_data  The multisig restore info and keys
+ */
+void wallet2::generate(const std::string& wallet_, const epee::wipeable_string& password,
+  const std::string& multisig_data)
+{
+  clear();
+  prepare_file_names(wallet_);
+
+  if (!wallet_.empty())
+  {
+    boost::system::error_code ignored_ec;
+    THROW_WALLET_EXCEPTION_IF(boost::filesystem::exists(m_wallet_file, ignored_ec), error::file_exists, m_wallet_file);
+    THROW_WALLET_EXCEPTION_IF(boost::filesystem::exists(m_keys_file,   ignored_ec), error::file_exists, m_keys_file);
+  }
+
+  m_account.generate(rct::rct2sk(rct::zero()), true, false);
+
+  THROW_WALLET_EXCEPTION_IF(multisig_data.size() < 32, error::invalid_multisig_seed);
+  size_t offset = 0;
+  uint32_t threshold = *(uint32_t*)(multisig_data.data() + offset);
+  offset += sizeof(uint32_t);
+  uint32_t total = *(uint32_t*)(multisig_data.data() + offset);
+  offset += sizeof(uint32_t);
+  THROW_WALLET_EXCEPTION_IF(threshold < 2, error::invalid_multisig_seed);
+  THROW_WALLET_EXCEPTION_IF(total != threshold && total != threshold + 1, error::invalid_multisig_seed);
+  const size_t n_multisig_keys =  total == threshold ? 1 : threshold;
+  THROW_WALLET_EXCEPTION_IF(multisig_data.size() != 8 + 32 * (4 + n_multisig_keys + total), error::invalid_multisig_seed);
+
+  std::vector<crypto::secret_key> multisig_keys;
+  std::vector<crypto::public_key> multisig_signers;
+  crypto::secret_key spend_secret_key = *(crypto::secret_key*)(multisig_data.data() + offset);
+  offset += sizeof(crypto::secret_key);
+  crypto::public_key spend_public_key = *(crypto::public_key*)(multisig_data.data() + offset);
+  offset += sizeof(crypto::public_key);
+  crypto::secret_key view_secret_key = *(crypto::secret_key*)(multisig_data.data() + offset);
+  offset += sizeof(crypto::secret_key);
+  crypto::public_key view_public_key = *(crypto::public_key*)(multisig_data.data() + offset);
+  offset += sizeof(crypto::public_key);
+  for (size_t n = 0; n < n_multisig_keys; ++n)
+  {
+    multisig_keys.push_back(*(crypto::secret_key*)(multisig_data.data() + offset));
+    offset += sizeof(crypto::secret_key);
+  }
+  for (size_t n = 0; n < total; ++n)
+  {
+    multisig_signers.push_back(*(crypto::public_key*)(multisig_data.data() + offset));
+    offset += sizeof(crypto::public_key);
+  }
+
+  crypto::public_key calculated_view_public_key;
+  THROW_WALLET_EXCEPTION_IF(!crypto::secret_key_to_public_key(view_secret_key, calculated_view_public_key), error::invalid_multisig_seed);
+  THROW_WALLET_EXCEPTION_IF(view_public_key != calculated_view_public_key, error::invalid_multisig_seed);
+  crypto::public_key local_signer;
+  THROW_WALLET_EXCEPTION_IF(!crypto::secret_key_to_public_key(spend_secret_key, local_signer), error::invalid_multisig_seed);
+  THROW_WALLET_EXCEPTION_IF(std::find(multisig_signers.begin(), multisig_signers.end(), local_signer) == multisig_signers.end(), error::invalid_multisig_seed);
+  rct::key skey = rct::zero();
+  for (const auto &msk: multisig_keys)
+    sc_add(skey.bytes, skey.bytes, rct::sk2rct(msk).bytes);
+  THROW_WALLET_EXCEPTION_IF(!(rct::rct2sk(skey) == spend_secret_key), error::invalid_multisig_seed);
+
+  m_account.make_multisig(view_secret_key, spend_secret_key, spend_public_key, multisig_keys);
+  m_account.finalize_multisig(spend_public_key);
+
+  m_account_public_address = m_account.get_keys().m_account_address;
+  m_watch_only = false;
+  m_multisig = true;
+  m_multisig_threshold = threshold;
+  m_multisig_signers = multisig_signers;
+
+  if (!wallet_.empty())
+  {
+    bool r = store_keys(m_keys_file, password, false);
+    THROW_WALLET_EXCEPTION_IF(!r, error::file_save_error, m_keys_file);
+
+    r = file_io_utils::save_string_to_file(m_wallet_file + ".address.txt", m_account.get_public_address_str(m_testnet));
+    if(!r) MERROR("String with address text not saved");
+  }
+
+  cryptonote::block b;
+  generate_genesis(b);
+  m_blockchain.push_back(get_block_hash(b));
+  add_subaddress_account(tr("Primary account"));
+
+  if (!wallet_.empty())
+    store();
+}
+
 /*!
  * \brief  Generates a wallet or restores one.
  * \param  wallet_        Name of wallet file

src/wallet/wallet2.h

@@ -435,6 +435,15 @@ 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
+     * \param  password       Password of wallet file
+     * \param  multisig_data  The multisig restore info and keys
+     */
+    void generate(const std::string& wallet_, const epee::wipeable_string& password,
+      const std::string& multisig_data);
+
     /*!
      * \brief Generates a wallet or restores one.
      * \param  wallet_        Name of wallet file
@@ -610,6 +619,7 @@ namespace tools
     bool watch_only() const { return m_watch_only; }
     bool multisig(bool *ready = NULL, uint32_t *threshold = NULL, uint32_t *total = NULL) const;
     bool has_multisig_partial_key_images() const;
+    bool get_multisig_seed(std::string& seed, const epee::wipeable_string &passphrase = std::string(), bool raw = true) const;
 
     // locked & unlocked balance of given or current subaddress account
     uint64_t balance(uint32_t subaddr_index_major) const;

src/wallet/wallet_errors.h

@@ -60,6 +60,7 @@ namespace tools
     //       file_save_error
     //       invalid_password
     //       invalid_priority
+    //       invalid_multisig_seed
     //       refresh_error *
     //         acc_outs_lookup_error
     //         block_parse_error
@@ -266,6 +267,16 @@ namespace tools
       std::string to_string() const { return wallet_logic_error::to_string(); }
     };
 
+    struct invalid_multisig_seed : public wallet_logic_error
+    {
+      explicit invalid_multisig_seed(std::string&& loc)
+        : wallet_logic_error(std::move(loc), "invalid multisig seed")
+      {
+      }
+
+      std::string to_string() const { return wallet_logic_error::to_string(); }
+    };
+
     //----------------------------------------------------------------------------------------------------
     struct invalid_pregenerated_random : public wallet_logic_error
     {