store secret keys encrypted where possible

The secret spend key is kept encrypted in memory, and
decrypted on the fly when needed.

Both spend and view secret keys are kept encrypted in a JSON
field in the keys file. This avoids leaving the keys in
memory due to being manipulated by the JSON I/O API.

5 files changed, 316 insertions, 75 deletions

diff --git a/src/wallet/api/wallet.cpp b/src/wallet/api/wallet.cpp
index e75bee5c9..bfd0e4aff 100644
--- a/src/wallet/api/wallet.cpp
+++ b/src/wallet/api/wallet.cpp
@@ -2032,7 +2032,8 @@ bool WalletImpl::isNewWallet() const
 
 bool WalletImpl::doInit(const string &daemon_address, uint64_t upper_transaction_size_limit, bool ssl)
 {
-    if (!m_wallet->init(daemon_address, m_daemon_login, upper_transaction_size_limit, ssl))
+    // claim RPC so there's no in-memory encryption for now
+    if (!m_wallet->init(true, daemon_address, m_daemon_login, upper_transaction_size_limit, ssl))
        return false;
 
     // in case new wallet, this will force fast-refresh (pulling hashes instead of blocks)
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index e61e437c0..ea3cca1ce 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -89,6 +89,7 @@ using namespace cryptonote;
 
 // arbitrary, used to generate different hashes from the same input
 #define CHACHA8_KEY_TAIL 0x8c
+#define CACHE_KEY_TAIL 0x8d
 
 #define UNSIGNED_TX_PREFIX "Monero unsigned tx set\004"
 #define SIGNED_TX_PREFIX "Monero signed tx set\004"
@@ -121,8 +122,6 @@ using namespace cryptonote;
 
 static const std::string MULTISIG_SIGNATURE_MAGIC = "SigMultisigPkV1";
 
-std::atomic<unsigned int> tools::wallet2::key_ref::refs(0);
-
 namespace
 {
   std::string get_default_ringdb_path()
@@ -197,7 +196,7 @@ std::string get_size_string(const cryptonote::blobdata &tx)
   return get_size_string(tx.size());
 }
 
-std::unique_ptr<tools::wallet2> make_basic(const boost::program_options::variables_map& vm, const options& opts, const std::function<boost::optional<tools::password_container>(const char *, bool)> &password_prompter)
+std::unique_ptr<tools::wallet2> make_basic(const boost::program_options::variables_map& vm, bool rpc, const options& opts, const std::function<boost::optional<tools::password_container>(const char *, bool)> &password_prompter)
 {
   const bool testnet = command_line::get_arg(vm, opts.testnet);
   const bool stagenet = command_line::get_arg(vm, opts.stagenet);
@@ -238,7 +237,7 @@ std::unique_ptr<tools::wallet2> make_basic(const boost::program_options::variabl
     daemon_address = std::string("http://") + daemon_host + ":" + std::to_string(daemon_port);
 
   std::unique_ptr<tools::wallet2> wallet(new tools::wallet2(nettype, kdf_rounds));
-  wallet->init(std::move(daemon_address), std::move(login));
+  wallet->init(rpc, 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());
   return wallet;
@@ -273,7 +272,7 @@ boost::optional<tools::password_container> get_password(const boost::program_opt
   return password_prompter(verify ? tr("Enter a new password for the wallet") : tr("Wallet password"), verify);
 }
 
-std::unique_ptr<tools::wallet2> generate_from_json(const std::string& json_file, const boost::program_options::variables_map& vm, const options& opts, const std::function<boost::optional<tools::password_container>(const char *, bool)> &password_prompter)
+std::unique_ptr<tools::wallet2> generate_from_json(const std::string& json_file, const boost::program_options::variables_map& vm, bool rpc, const options& opts, const std::function<boost::optional<tools::password_container>(const char *, bool)> &password_prompter)
 {
   const bool testnet = command_line::get_arg(vm, opts.testnet);
   const bool stagenet = command_line::get_arg(vm, opts.stagenet);
@@ -411,7 +410,7 @@ std::unique_ptr<tools::wallet2> generate_from_json(const std::string& json_file,
     THROW_WALLET_EXCEPTION_IF(deprecated_wallet, tools::error::wallet_internal_error,
       tools::wallet2::tr("Cannot generate deprecated wallets from JSON"));
 
-    wallet.reset(make_basic(vm, opts, password_prompter).release());
+    wallet.reset(make_basic(vm, rpc, opts, password_prompter).release());
     wallet->set_refresh_from_block_height(field_scan_from_height);
     wallet->explicit_refresh_from_block_height(field_scan_from_height_found);
 
@@ -648,6 +647,34 @@ const size_t MAX_SPLIT_ATTEMPTS = 30;
 constexpr const std::chrono::seconds wallet2::rpc_timeout;
 const char* wallet2::tr(const char* str) { return i18n_translate(str, "tools::wallet2"); }
 
+wallet_keys_unlocker::wallet_keys_unlocker(wallet2 &w, const boost::optional<tools::password_container> &password):
+  w(w),
+  locked(password != boost::none)
+{
+  if (!locked || w.is_rpc())
+    return;
+  const epee::wipeable_string pass = password->password();
+  w.generate_chacha_key_from_password(pass, key);
+  w.decrypt_keys(key);
+}
+
+wallet_keys_unlocker::wallet_keys_unlocker(wallet2 &w, bool locked, const epee::wipeable_string &password):
+  w(w),
+  locked(locked)
+{
+  if (!locked)
+    return;
+  w.generate_chacha_key_from_password(password, key);
+  w.decrypt_keys(key);
+}
+
+wallet_keys_unlocker::~wallet_keys_unlocker()
+{
+  if (!locked)
+    return;
+  w.encrypt_keys(key);
+}
+
 wallet2::wallet2(network_type nettype, uint64_t kdf_rounds):
   m_multisig_rescan_info(NULL),
   m_multisig_rescan_k(NULL),
@@ -693,7 +720,9 @@ wallet2::wallet2(network_type nettype, uint64_t kdf_rounds):
   m_key_on_device(false),
   m_ring_history_saved(false),
   m_ringdb(),
-  m_last_block_reward(0)
+  m_last_block_reward(0),
+  m_encrypt_keys_after_refresh(boost::none),
+  m_rpc(false)
 {
 }
 
@@ -726,14 +755,14 @@ void wallet2::init_options(boost::program_options::options_description& desc_par
   command_line::add_arg(desc_params, opts.kdf_rounds);
 }
 
-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)
+std::unique_ptr<wallet2> wallet2::make_from_json(const boost::program_options::variables_map& vm, bool rpc, const std::string& json_file, const std::function<boost::optional<tools::password_container>(const char *, bool)> &password_prompter)
 {
   const options opts{};
-  return generate_from_json(json_file, vm, opts, password_prompter);
+  return generate_from_json(json_file, vm, rpc, opts, password_prompter);
 }
 
 std::pair<std::unique_ptr<wallet2>, password_container> wallet2::make_from_file(
-  const boost::program_options::variables_map& vm, const std::string& wallet_file, const std::function<boost::optional<tools::password_container>(const char *, bool)> &password_prompter)
+  const boost::program_options::variables_map& vm, bool rpc, const std::string& wallet_file, const std::function<boost::optional<tools::password_container>(const char *, bool)> &password_prompter)
 {
   const options opts{};
   auto pwd = get_password(vm, opts, password_prompter, false);
@@ -741,7 +770,7 @@ std::pair<std::unique_ptr<wallet2>, password_container> wallet2::make_from_file(
   {
     return {nullptr, password_container{}};
   }
-  auto wallet = make_basic(vm, opts, password_prompter);
+  auto wallet = make_basic(vm, rpc, opts, password_prompter);
   if (wallet)
   {
     wallet->load(wallet_file, pwd->password());
@@ -749,7 +778,7 @@ std::pair<std::unique_ptr<wallet2>, password_container> wallet2::make_from_file(
   return {std::move(wallet), std::move(*pwd)};
 }
 
-std::pair<std::unique_ptr<wallet2>, password_container> wallet2::make_new(const boost::program_options::variables_map& vm, const std::function<boost::optional<password_container>(const char *, bool)> &password_prompter)
+std::pair<std::unique_ptr<wallet2>, password_container> wallet2::make_new(const boost::program_options::variables_map& vm, bool rpc, const std::function<boost::optional<password_container>(const char *, bool)> &password_prompter)
 {
   const options opts{};
   auto pwd = get_password(vm, opts, password_prompter, true);
@@ -757,18 +786,19 @@ std::pair<std::unique_ptr<wallet2>, password_container> wallet2::make_new(const
   {
     return {nullptr, password_container{}};
   }
-  return {make_basic(vm, opts, password_prompter), std::move(*pwd)};
+  return {make_basic(vm, rpc, opts, password_prompter), std::move(*pwd)};
 }
 
-std::unique_ptr<wallet2> wallet2::make_dummy(const boost::program_options::variables_map& vm, const std::function<boost::optional<tools::password_container>(const char *, bool)> &password_prompter)
+std::unique_ptr<wallet2> wallet2::make_dummy(const boost::program_options::variables_map& vm, bool rpc, const std::function<boost::optional<tools::password_container>(const char *, bool)> &password_prompter)
 {
   const options opts{};
-  return make_basic(vm, opts, password_prompter);
+  return make_basic(vm, rpc, opts, password_prompter);
 }
 
 //----------------------------------------------------------------------------------------------------
-bool wallet2::init(std::string daemon_address, boost::optional<epee::net_utils::http::login> daemon_login, uint64_t upper_transaction_size_limit, bool ssl)
+bool wallet2::init(bool rpc, std::string daemon_address, boost::optional<epee::net_utils::http::login> daemon_login, uint64_t upper_transaction_size_limit, bool ssl)
 {
+  m_rpc = rpc;
   m_checkpoints.init_default_checkpoints(m_nettype);
   if(m_http_client.is_connected())
     m_http_client.disconnect();
@@ -785,8 +815,7 @@ bool wallet2::is_deterministic() const
   crypto::secret_key second;
   keccak((uint8_t *)&get_account().get_keys().m_spend_secret_key, sizeof(crypto::secret_key), (uint8_t *)&second, sizeof(crypto::secret_key));
   sc_reduce32((uint8_t *)&second);
-  bool keys_deterministic = memcmp(second.data,get_account().get_keys().m_view_secret_key.data, sizeof(crypto::secret_key)) == 0;
-  return keys_deterministic;
+  return memcmp(second.data,get_account().get_keys().m_view_secret_key.data, sizeof(crypto::secret_key)) == 0;
 }
 //----------------------------------------------------------------------------------------------------
 bool wallet2::get_seed(epee::wipeable_string& electrum_words, const epee::wipeable_string &passphrase) const
@@ -1103,9 +1132,25 @@ static uint64_t decodeRct(const rct::rctSig & rv, const crypto::key_derivation &
   }
 }
 //----------------------------------------------------------------------------------------------------
-void wallet2::scan_output(const cryptonote::transaction &tx, const crypto::public_key &tx_pub_key, size_t i, tx_scan_info_t &tx_scan_info, int &num_vouts_received, std::unordered_map<cryptonote::subaddress_index, uint64_t> &tx_money_got_in_outs, std::vector<size_t> &outs) const
+void wallet2::scan_output(const cryptonote::transaction &tx, const crypto::public_key &tx_pub_key, size_t i, tx_scan_info_t &tx_scan_info, int &num_vouts_received, std::unordered_map<cryptonote::subaddress_index, uint64_t> &tx_money_got_in_outs, std::vector<size_t> &outs)
 {
   THROW_WALLET_EXCEPTION_IF(i >= tx.vout.size(), error::wallet_internal_error, "Invalid vout index");
+
+  // if keys are encrypted, ask for password
+  if (m_ask_password && !m_rpc && !m_watch_only && !m_multisig_rescan_k)
+  {
+    static critical_section password_lock;
+    CRITICAL_REGION_LOCAL(password_lock);
+    if (!m_encrypt_keys_after_refresh)
+    {
+      boost::optional<epee::wipeable_string> pwd = m_callback->on_get_password("output received");
+      THROW_WALLET_EXCEPTION_IF(!pwd, error::password_needed, tr("Password is needed to compute key image for incoming monero"));
+      THROW_WALLET_EXCEPTION_IF(!verify_password(*pwd), error::password_needed, tr("Invalid password: password is needed to compute key image for incoming monero"));
+      decrypt_keys(*pwd);
+      m_encrypt_keys_after_refresh = *pwd;
+    }
+  }
+
   if (m_multisig)
   {
     tx_scan_info.in_ephemeral.pub = boost::get<cryptonote::txout_to_key>(tx.vout[i].target).key;
@@ -2063,6 +2108,14 @@ void wallet2::update_pool_state(bool refreshed)
 {
   MDEBUG("update_pool_state start");
 
+  auto keys_reencryptor = epee::misc_utils::create_scope_leave_handler([&, this]() {
+    if (m_encrypt_keys_after_refresh)
+    {
+      encrypt_keys(*m_encrypt_keys_after_refresh);
+      m_encrypt_keys_after_refresh = boost::none;
+    }
+  });
+
   // get the pool state
   cryptonote::COMMAND_RPC_GET_TRANSACTION_POOL_HASHES_BIN::request req;
   cryptonote::COMMAND_RPC_GET_TRANSACTION_POOL_HASHES_BIN::response res;
@@ -2369,8 +2422,6 @@ bool wallet2::delete_address_book_row(std::size_t row_id) {
 //----------------------------------------------------------------------------------------------------
 void wallet2::refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blocks_fetched, bool& received_money)
 {
-  key_ref kref(*this);
-
   if(m_light_wallet) {
 
     // MyMonero get_address_info needs to be called occasionally to trigger wallet sync.
@@ -2438,6 +2489,14 @@ void wallet2::refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blo
   // subsequent pulls in this refresh.
   start_height = 0;
 
+  auto keys_reencryptor = epee::misc_utils::create_scope_leave_handler([&, this]() {
+    if (m_encrypt_keys_after_refresh)
+    {
+      encrypt_keys(*m_encrypt_keys_after_refresh);
+      m_encrypt_keys_after_refresh = boost::none;
+    }
+  });
+
   bool first = true;
   while(m_run.load(std::memory_order_relaxed))
   {
@@ -2507,6 +2566,12 @@ void wallet2::refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blo
         throw std::runtime_error("proxy exception in refresh thread");
       }
     }
+    catch (const tools::error::password_needed&)
+    {
+      blocks_fetched += added_blocks;
+      waiter.wait(&tpool);
+      throw;
+    }
     catch (const std::exception&)
     {
       blocks_fetched += added_blocks;
@@ -2728,8 +2793,20 @@ bool wallet2::store_keys(const std::string& keys_file_name, const epee::wipeable
   std::string multisig_signers;
   cryptonote::account_base account = m_account;
 
+  crypto::chacha_key key;
+  crypto::generate_chacha_key(password.data(), password.size(), key, m_kdf_rounds);
+
+  if (m_ask_password && !m_rpc && !m_watch_only)
+  {
+    account.encrypt_viewkey(key);
+    account.decrypt_keys(key);
+  }
+
   if (watch_only)
     account.forget_spend_key();
+
+  account.encrypt_keys(key);
+
   bool r = epee::serialization::store_t_to_binary(account, account_data);
   CHECK_AND_ASSERT_MES(r, false, "failed to serialize wallet keys");
   wallet2::keys_file_data keys_file_data = boost::value_initialized<wallet2::keys_file_data>();
@@ -2846,6 +2923,9 @@ 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.SetUint(1);
+  json.AddMember("encrypted_secret_keys", value2, json.GetAllocator());
+
   // Serialize the JSON object
   rapidjson::StringBuffer buffer;
   rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
@@ -2853,7 +2933,6 @@ bool wallet2::store_keys(const std::string& keys_file_name, const epee::wipeable
   account_data = buffer.GetString();
 
   // Encrypt the entire JSON object.
-  crypto::chacha_key key;
   crypto::generate_chacha_key(password.data(), password.size(), key, m_kdf_rounds);
   std::string cipher;
   cipher.resize(account_data.size());
@@ -2871,6 +2950,35 @@ bool wallet2::store_keys(const std::string& keys_file_name, const epee::wipeable
   return true;
 }
 //----------------------------------------------------------------------------------------------------
+void wallet2::setup_keys(const epee::wipeable_string &password)
+{
+  crypto::chacha_key key;
+  crypto::generate_chacha_key(password.data(), password.size(), key, m_kdf_rounds);
+
+  // re-encrypt, but keep viewkey unencrypted
+  if (m_ask_password && !m_rpc && !m_watch_only)
+  {
+    m_account.encrypt_keys(key);
+    m_account.decrypt_viewkey(key);
+  }
+
+  static_assert(HASH_SIZE == sizeof(crypto::chacha_key), "Mismatched sizes of hash and chacha key");
+  tools::scrubbed_arr<char, HASH_SIZE+1> cache_key_data;
+  memcpy(cache_key_data.data(), &key, HASH_SIZE);
+  cache_key_data[HASH_SIZE] = CACHE_KEY_TAIL;
+  cn_fast_hash(cache_key_data.data(), HASH_SIZE+1, (crypto::hash&)m_cache_key);
+  get_ringdb_key();
+}
+//----------------------------------------------------------------------------------------------------
+void wallet2::change_password(const std::string &filename, const epee::wipeable_string &original_password, const epee::wipeable_string &new_password)
+{
+  if (m_ask_password && !m_rpc && !m_watch_only)
+    decrypt_keys(original_password);
+  setup_keys(new_password);
+  rewrite(filename, new_password);
+  store();
+}
+//----------------------------------------------------------------------------------------------------
 /*!
  * \brief Load wallet information from wallet file.
  * \param keys_file_name Name of wallet file
@@ -2881,6 +2989,7 @@ bool wallet2::load_keys(const std::string& keys_file_name, const epee::wipeable_
   rapidjson::Document json;
   wallet2::keys_file_data keys_file_data;
   std::string buf;
+  bool encrypted_secret_keys = false;
   bool r = epee::file_io_utils::load_file_to_string(keys_file_name, buf);
   THROW_WALLET_EXCEPTION_IF(!r, error::file_read_error, keys_file_name);
 
@@ -2926,6 +3035,7 @@ bool wallet2::load_keys(const std::string& keys_file_name, const epee::wipeable_
     m_subaddress_lookahead_major = SUBADDRESS_LOOKAHEAD_MAJOR;
     m_subaddress_lookahead_minor = SUBADDRESS_LOOKAHEAD_MINOR;
     m_key_on_device = false;
+    encrypted_secret_keys = false;
   }
   else if(json.IsObject())
   {
@@ -3055,6 +3165,8 @@ 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;
+    GET_FIELD_FROM_JSON_RETURN_ON_ERROR(json, encrypted_secret_keys, uint32_t, Uint, false, false);
+    encrypted_secret_keys = field_encrypted_secret_keys;
   }
   else
   {
@@ -3071,12 +3183,39 @@ bool wallet2::load_keys(const std::string& keys_file_name, const epee::wipeable_
     m_account.set_device(hwdev);
     LOG_PRINT_L0("Device inited...");
   }
+
+  if (r)
+  {
+    if (encrypted_secret_keys)
+    {
+      m_account.decrypt_keys(key);
+    }
+    else
+    {
+      // rewrite with encrypted keys, ignore errors
+      if (m_ask_password && !m_rpc && !m_watch_only)
+        encrypt_keys(key);
+      bool saved_ret = store_keys(keys_file_name, password, m_watch_only);
+      if (!saved_ret)
+      {
+        // just moan a bit, but not fatal
+        MERROR("Error saving keys file with encrypted keys, not fatal");
+      }
+      if (m_ask_password && !m_rpc && !m_watch_only)
+        decrypt_keys(key);
+      m_keys_file_locker.reset();
+    }
+  }
   const cryptonote::account_keys& keys = m_account.get_keys();
   hw::device &hwdev = m_account.get_device();
   r = r && hwdev.verify_keys(keys.m_view_secret_key,  keys.m_account_address.m_view_public_key);
   if(!m_watch_only && !m_multisig)
     r = r && hwdev.verify_keys(keys.m_spend_secret_key, keys.m_account_address.m_spend_public_key);
   THROW_WALLET_EXCEPTION_IF(!r, error::invalid_password);
+
+  if (r)
+    setup_keys(password);
+
   return true;
 }
 
@@ -3117,6 +3256,7 @@ bool wallet2::verify_password(const std::string& keys_file_name, const epee::wip
   rapidjson::Document json;
   wallet2::keys_file_data keys_file_data;
   std::string buf;
+  bool encrypted_secret_keys = false;
   bool r = epee::file_io_utils::load_file_to_string(keys_file_name, buf);
   THROW_WALLET_EXCEPTION_IF(!r, error::file_read_error, keys_file_name);
 
@@ -3140,19 +3280,50 @@ bool wallet2::verify_password(const std::string& keys_file_name, const epee::wip
   {
     account_data = std::string(json["key_data"].GetString(), json["key_data"].GetString() +
       json["key_data"].GetStringLength());
+    GET_FIELD_FROM_JSON_RETURN_ON_ERROR(json, encrypted_secret_keys, uint32_t, Uint, false, false);
+    encrypted_secret_keys = field_encrypted_secret_keys;
   }
 
   cryptonote::account_base account_data_check;
 
   r = epee::serialization::load_t_from_binary(account_data_check, account_data);
-  const cryptonote::account_keys& keys = account_data_check.get_keys();
 
+  if (encrypted_secret_keys)
+    account_data_check.decrypt_keys(key);
+
+  const cryptonote::account_keys& keys = account_data_check.get_keys();
   r = r && hwdev.verify_keys(keys.m_view_secret_key,  keys.m_account_address.m_view_public_key);
   if(!no_spend_key)
     r = r && hwdev.verify_keys(keys.m_spend_secret_key, keys.m_account_address.m_spend_public_key);
   return r;
 }
 
+void wallet2::encrypt_keys(const crypto::chacha_key &key)
+{
+  m_account.encrypt_keys(key);
+  m_account.decrypt_viewkey(key);
+}
+
+void wallet2::decrypt_keys(const crypto::chacha_key &key)
+{
+  m_account.encrypt_viewkey(key);
+  m_account.decrypt_keys(key);
+}
+
+void wallet2::encrypt_keys(const epee::wipeable_string &password)
+{
+  crypto::chacha_key key;
+  crypto::generate_chacha_key(password.data(), password.size(), key, m_kdf_rounds);
+  encrypt_keys(key);
+}
+
+void wallet2::decrypt_keys(const epee::wipeable_string &password)
+{
+  crypto::chacha_key key;
+  crypto::generate_chacha_key(password.data(), password.size(), key, m_kdf_rounds);
+  decrypt_keys(key);
+}
+
 /*!
  * \brief  Generates a wallet or restores one.
  * \param  wallet_              Name of wallet file
@@ -3227,6 +3398,7 @@ void wallet2::generate(const std::string& wallet_, const epee::wipeable_string&
   m_multisig_threshold = threshold;
   m_multisig_signers = multisig_signers;
   m_key_on_device = false;
+  setup_keys(password);
 
   if (!wallet_.empty())
   {
@@ -3281,6 +3453,7 @@ crypto::secret_key wallet2::generate(const std::string& wallet_, const epee::wip
   m_multisig_threshold = 0;
   m_multisig_signers.clear();
   m_key_on_device = false;
+  setup_keys(password);
 
   // calculate a starting refresh height
   if(m_refresh_from_block_height == 0 && !recover){
@@ -3382,6 +3555,7 @@ void wallet2::generate(const std::string& wallet_, const epee::wipeable_string&
   m_multisig_threshold = 0;
   m_multisig_signers.clear();
   m_key_on_device = false;
+  setup_keys(password);
 
   if (!wallet_.empty())
   {
@@ -3435,6 +3609,7 @@ void wallet2::generate(const std::string& wallet_, const epee::wipeable_string&
   m_multisig_threshold = 0;
   m_multisig_signers.clear();
   m_key_on_device = false;
+  setup_keys(password);
 
   if (!wallet_.empty())
   {
@@ -3481,6 +3656,7 @@ void wallet2::restore(const std::string& wallet_, const epee::wipeable_string& p
   m_multisig = false;
   m_multisig_threshold = 0;
   m_multisig_signers.clear();
+  setup_keys(password);
 
   if (!wallet_.empty()) {
     bool r = store_keys(m_keys_file, password, false);
@@ -3520,6 +3696,17 @@ std::string wallet2::make_multisig(const epee::wipeable_string &password,
 
   clear();
 
+  // decrypt keys
+  epee::misc_utils::auto_scope_leave_caller keys_reencryptor;
+  if (m_ask_password && !m_rpc && !m_watch_only)
+  {
+    crypto::chacha_key chacha_key;
+    crypto::generate_chacha_key(password.data(), password.size(), chacha_key, m_kdf_rounds);
+    m_account.encrypt_viewkey(chacha_key);
+    m_account.decrypt_keys(chacha_key);
+    keys_reencryptor = epee::misc_utils::create_scope_leave_handler([&, this, chacha_key]() { m_account.encrypt_keys(chacha_key); m_account.decrypt_viewkey(chacha_key); });
+  }
+
   MINFO("Creating spend key...");
   std::vector<crypto::secret_key> multisig_keys;
   rct::key spend_pkey, spend_skey;
@@ -3580,6 +3767,9 @@ std::string wallet2::make_multisig(const epee::wipeable_string &password,
     m_multisig_signers = std::vector<crypto::public_key>(spend_keys.size() + 1, crypto::null_pkey);
   }
 
+  // re-encrypt keys
+  keys_reencryptor = epee::misc_utils::auto_scope_leave_caller();
+
   if (!m_wallet_file.empty())
   {
     bool r = store_keys(m_keys_file, password, false);
@@ -3662,6 +3852,17 @@ bool wallet2::finalize_multisig(const epee::wipeable_string &password, std::unor
 {
   CHECK_AND_ASSERT_THROW_MES(!pkeys.empty(), "empty pkeys");
 
+  // keys are decrypted
+  epee::misc_utils::auto_scope_leave_caller keys_reencryptor;
+  if (m_ask_password && !m_rpc && !m_watch_only)
+  {
+    crypto::chacha_key chacha_key;
+    crypto::generate_chacha_key(password.data(), password.size(), chacha_key, m_kdf_rounds);
+    m_account.encrypt_viewkey(chacha_key);
+    m_account.decrypt_keys(chacha_key);
+    keys_reencryptor = epee::misc_utils::create_scope_leave_handler([&, this, chacha_key]() { m_account.encrypt_keys(chacha_key); m_account.decrypt_viewkey(chacha_key); });
+  }
+
   // add ours if not included
   crypto::public_key local_signer;
   CHECK_AND_ASSERT_THROW_MES(crypto::secret_key_to_public_key(get_account().get_keys().m_spend_secret_key, local_signer),
@@ -3684,6 +3885,9 @@ bool wallet2::finalize_multisig(const epee::wipeable_string &password, std::unor
   m_multisig_signers = signers;
   std::sort(m_multisig_signers.begin(), m_multisig_signers.end(), [](const crypto::public_key &e0, const crypto::public_key &e1){ return memcmp(&e0, &e1, sizeof(e0)); });
 
+  // keys are encrypted again
+  keys_reencryptor = epee::misc_utils::auto_scope_leave_caller();
+
   if (!m_wallet_file.empty())
   {
     bool r = store_keys(m_keys_file, password, false);
@@ -3995,6 +4199,11 @@ bool wallet2::generate_chacha_key_from_secret_keys(crypto::chacha_key &key) cons
   return hwdev.generate_chacha_key(m_account.get_keys(), key, m_kdf_rounds);
 }
 //----------------------------------------------------------------------------------------------------
+void wallet2::generate_chacha_key_from_password(const epee::wipeable_string &pass, crypto::chacha_key &key) const
+{
+  crypto::generate_chacha_key(pass.data(), pass.size(), key, m_kdf_rounds);
+}
+//----------------------------------------------------------------------------------------------------
 void wallet2::load(const std::string& wallet_, const epee::wipeable_string& password)
 {
   clear();
@@ -4015,6 +4224,8 @@ void wallet2::load(const std::string& wallet_, const epee::wipeable_string& pass
   LOG_PRINT_L0("Loaded wallet keys file, with public address: " << m_account.get_public_address_str(m_nettype));
   lock_keys_file();
 
+  wallet_keys_unlocker unlocker(*this, m_ask_password && !m_rpc && !m_watch_only, password);
+
   //keys loaded ok!
   //try to load wallet file. but even if we failed, it is not big problem
   if(!boost::filesystem::exists(m_wallet_file, e) || e)
@@ -4036,11 +4247,9 @@ void wallet2::load(const std::string& wallet_, const epee::wipeable_string& pass
 
       r = ::serialization::parse_binary(buf, cache_file_data);
       THROW_WALLET_EXCEPTION_IF(!r, error::wallet_internal_error, "internal error: failed to deserialize \"" + m_wallet_file + '\"');
-      crypto::chacha_key key;
-      generate_chacha_key_from_secret_keys(key);
       std::string cache_data;
       cache_data.resize(cache_file_data.cache_data.size());
-      crypto::chacha20(cache_file_data.cache_data.data(), cache_file_data.cache_data.size(), key, cache_file_data.iv, &cache_data[0]);
+      crypto::chacha20(cache_file_data.cache_data.data(), cache_file_data.cache_data.size(), m_cache_key, cache_file_data.iv, &cache_data[0]);
 
       try {
         std::stringstream iss;
@@ -4048,11 +4257,13 @@ void wallet2::load(const std::string& wallet_, const epee::wipeable_string& pass
         boost::archive::portable_binary_iarchive ar(iss);
         ar >> *this;
       }
-      catch (...)
+      catch(...)
       {
-        crypto::chacha8(cache_file_data.cache_data.data(), cache_file_data.cache_data.size(), key, cache_file_data.iv, &cache_data[0]);
-        try
-        {
+        // try with previous scheme: direct from keys
+        crypto::chacha_key key;
+        generate_chacha_key_from_secret_keys(key);
+        crypto::chacha20(cache_file_data.cache_data.data(), cache_file_data.cache_data.size(), key, cache_file_data.iv, &cache_data[0]);
+        try {
           std::stringstream iss;
           iss << cache_data;
           boost::archive::portable_binary_iarchive ar(iss);
@@ -4060,13 +4271,24 @@ void wallet2::load(const std::string& wallet_, const epee::wipeable_string& pass
         }
         catch (...)
         {
-          LOG_PRINT_L0("Failed to open portable binary, trying unportable");
-          boost::filesystem::copy_file(m_wallet_file, m_wallet_file + ".unportable", boost::filesystem::copy_option::overwrite_if_exists);
-          std::stringstream iss;
-          iss.str("");
-          iss << cache_data;
-          boost::archive::binary_iarchive ar(iss);
-          ar >> *this;
+          crypto::chacha8(cache_file_data.cache_data.data(), cache_file_data.cache_data.size(), key, cache_file_data.iv, &cache_data[0]);
+          try
+          {
+            std::stringstream iss;
+            iss << cache_data;
+            boost::archive::portable_binary_iarchive ar(iss);
+            ar >> *this;
+          }
+          catch (...)
+          {
+            LOG_PRINT_L0("Failed to open portable binary, trying unportable");
+            boost::filesystem::copy_file(m_wallet_file, m_wallet_file + ".unportable", boost::filesystem::copy_option::overwrite_if_exists);
+            std::stringstream iss;
+            iss.str("");
+            iss << cache_data;
+            boost::archive::binary_iarchive ar(iss);
+            ar >> *this;
+          }
         }
       }
     }
@@ -4218,12 +4440,10 @@ void wallet2::store_to(const std::string &path, const epee::wipeable_string &pas
 
   wallet2::cache_file_data cache_file_data = boost::value_initialized<wallet2::cache_file_data>();
   cache_file_data.cache_data = oss.str();
-  crypto::chacha_key key;
-  generate_chacha_key_from_secret_keys(key);
   std::string cipher;
   cipher.resize(cache_file_data.cache_data.size());
   cache_file_data.iv = crypto::rand<crypto::chacha_iv>();
-  crypto::chacha20(cache_file_data.cache_data.data(), cache_file_data.cache_data.size(), key, cache_file_data.iv, &cipher[0]);
+  crypto::chacha20(cache_file_data.cache_data.data(), cache_file_data.cache_data.size(), m_cache_key, cache_file_data.iv, &cipher[0]);
   cache_file_data.cache_data = cipher;
 
   const std::string new_file = same_file ? m_wallet_file + ".new" : path;
@@ -5861,12 +6081,6 @@ crypto::chacha_key wallet2::get_ringdb_key()
   return *m_ringdb_key;
 }
 
-void wallet2::clear_ringdb_key()
-{
-  MINFO("clearing ringdb key");
-  m_ringdb_key = boost::none;
-}
-
 bool wallet2::add_rings(const crypto::chacha_key &key, const cryptonote::transaction_prefix &tx)
 {
   if (!m_ringdb)
@@ -5877,7 +6091,6 @@ bool wallet2::add_rings(const crypto::chacha_key &key, const cryptonote::transac
 
 bool wallet2::add_rings(const cryptonote::transaction_prefix &tx)
 {
-  key_ref kref(*this);
   try { return add_rings(get_ringdb_key(), tx); }
   catch (const std::exception &e) { return false; }
 }
@@ -5886,7 +6099,6 @@ bool wallet2::remove_rings(const cryptonote::transaction_prefix &tx)
 {
   if (!m_ringdb)
     return false;
-  key_ref kref(*this);
   try { return m_ringdb->remove_rings(get_ringdb_key(), tx); }
   catch (const std::exception &e) { return false; }
 }
@@ -5924,7 +6136,6 @@ bool wallet2::get_rings(const crypto::hash &txid, std::vector<std::pair<crypto::
 
 bool wallet2::get_ring(const crypto::key_image &key_image, std::vector<uint64_t> &outs)
 {
-  key_ref kref(*this);
   try { return get_ring(get_ringdb_key(), key_image, outs); }
   catch (const std::exception &e) { return false; }
 }
@@ -5934,7 +6145,6 @@ bool wallet2::set_ring(const crypto::key_image &key_image, const std::vector<uin
   if (!m_ringdb)
     return false;
 
-  key_ref kref(*this);
   try { return m_ringdb->set_ring(get_ringdb_key(), key_image, outs, relative); }
   catch (const std::exception &e) { return false; }
 }
@@ -5946,7 +6156,6 @@ bool wallet2::find_and_save_rings(bool force)
   if (!m_ringdb)
     return false;
 
-  key_ref kref(*this);
   COMMAND_RPC_GET_TRANSACTIONS::request req = AUTO_VAL_INIT(req);
   COMMAND_RPC_GET_TRANSACTIONS::response res = AUTO_VAL_INIT(res);
 
@@ -10662,6 +10871,7 @@ size_t wallet2::import_multisig(std::vector<cryptonote::blobdata> blobs)
   m_multisig_rescan_info = &info;
   try
   {
+
     refresh(false);
   }
   catch (...) {}
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index 86fee0da7..2d45f4e3e 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -67,6 +67,19 @@ class Serialization_portability_wallet_Test;
 namespace tools
 {
   class ringdb;
+  class wallet2;
+
+  class wallet_keys_unlocker
+  {
+  public:
+    wallet_keys_unlocker(wallet2 &w, const boost::optional<tools::password_container> &password);
+    wallet_keys_unlocker(wallet2 &w, bool locked, const epee::wipeable_string &password);
+    ~wallet_keys_unlocker();
+  private:
+    wallet2 &w;
+    bool locked;
+    crypto::chacha_key key;
+  };
 
   class i_wallet2_callback
   {
@@ -77,6 +90,7 @@ namespace tools
     virtual void on_unconfirmed_money_received(uint64_t height, const crypto::hash &txid, const cryptonote::transaction& tx, uint64_t amount, const cryptonote::subaddress_index& subaddr_index) {}
     virtual void on_money_spent(uint64_t height, const crypto::hash &txid, const cryptonote::transaction& in_tx, uint64_t amount, const cryptonote::transaction& spend_tx, const cryptonote::subaddress_index& subaddr_index) {}
     virtual void on_skip_transaction(uint64_t height, const crypto::hash &txid, const cryptonote::transaction& tx) {}
+    virtual boost::optional<epee::wipeable_string> on_get_password(const char *reason) { return boost::none; }
     // Light wallet callbacks
     virtual void on_lw_new_block(uint64_t height) {}
     virtual void on_lw_money_received(uint64_t height, const crypto::hash &txid, uint64_t amount) {}
@@ -133,9 +147,11 @@ namespace tools
     std::deque<crypto::hash> m_blockchain;
   };
 
+  class wallet_keys_unlocker;
   class wallet2
   {
     friend class ::Serialization_portability_wallet_Test;
+    friend class wallet_keys_unlocker;
   public:
     static constexpr const std::chrono::seconds rpc_timeout = std::chrono::minutes(3) + std::chrono::seconds(30);
 
@@ -153,17 +169,17 @@ namespace tools
     static void init_options(boost::program_options::options_description& desc_params);
 
     //! Uses stdin and stdout. Returns a wallet2 if no errors.
-    static std::unique_ptr<wallet2> make_from_json(const boost::program_options::variables_map& vm, const std::string& json_file, const std::function<boost::optional<password_container>(const char *, bool)> &password_prompter);
+    static std::unique_ptr<wallet2> make_from_json(const boost::program_options::variables_map& vm, bool rpc, const std::string& json_file, const std::function<boost::optional<password_container>(const char *, bool)> &password_prompter);
 
     //! Uses stdin and stdout. Returns a wallet2 and password for `wallet_file` if no errors.
     static std::pair<std::unique_ptr<wallet2>, password_container>
-      make_from_file(const boost::program_options::variables_map& vm, const std::string& wallet_file, const std::function<boost::optional<password_container>(const char *, bool)> &password_prompter);
+      make_from_file(const boost::program_options::variables_map& vm, bool rpc, const std::string& wallet_file, const std::function<boost::optional<password_container>(const char *, bool)> &password_prompter);
 
     //! Uses stdin and stdout. Returns a wallet2 and password for wallet with no file if no errors.
-    static std::pair<std::unique_ptr<wallet2>, password_container> make_new(const boost::program_options::variables_map& vm, const std::function<boost::optional<password_container>(const char *, bool)> &password_prompter);
+    static std::pair<std::unique_ptr<wallet2>, password_container> make_new(const boost::program_options::variables_map& vm, bool rpc, const std::function<boost::optional<password_container>(const char *, bool)> &password_prompter);
 
     //! Just parses variables.
-    static std::unique_ptr<wallet2> make_dummy(const boost::program_options::variables_map& vm, const std::function<boost::optional<password_container>(const char *, bool)> &password_prompter);
+    static std::unique_ptr<wallet2> make_dummy(const boost::program_options::variables_map& vm, bool rpc, const std::function<boost::optional<password_container>(const char *, bool)> &password_prompter);
 
     static bool verify_password(const std::string& keys_file_name, const epee::wipeable_string& password, bool no_spend_key, hw::device &hwdev, uint64_t kdf_rounds);
 
@@ -477,16 +493,6 @@ namespace tools
       std::vector<is_out_data> additional;
     };
 
-    struct key_ref
-    {
-      key_ref(tools::wallet2 &w): wallet(w) { ++refs; }
-      ~key_ref() { if (!--refs) wallet.clear_ringdb_key(); }
-
-    private:
-      tools::wallet2 &wallet;
-      static std::atomic<unsigned int> refs;
-    };
-
     /*!
      * \brief  Generates a wallet or restores one.
      * \param  wallet_              Name of wallet file
@@ -613,6 +619,11 @@ namespace tools
     cryptonote::account_base& get_account(){return m_account;}
     const cryptonote::account_base& get_account()const{return m_account;}
 
+    void encrypt_keys(const crypto::chacha_key &key);
+    void encrypt_keys(const epee::wipeable_string &password);
+    void decrypt_keys(const crypto::chacha_key &key);
+    void decrypt_keys(const epee::wipeable_string &password);
+
     void set_refresh_from_block_height(uint64_t height) {m_refresh_from_block_height = height;}
     uint64_t get_refresh_from_block_height() const {return m_refresh_from_block_height;}
 
@@ -625,7 +636,7 @@ namespace tools
     // into account the current median block size rather than
     // the minimum block size.
     bool deinit();
-    bool init(std::string daemon_address = "http://localhost:8080",
+    bool init(bool rpc, 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); }
@@ -1077,6 +1088,8 @@ namespace tools
     uint64_t adjust_mixin(uint64_t mixin) const;
     uint32_t adjust_priority(uint32_t priority);
 
+    bool is_rpc() const { return m_rpc; }
+
     // Light wallet specific functions
     // fetch unspent outs from lw node and store in m_transfers
     void light_wallet_get_unspent_outs();
@@ -1153,6 +1166,9 @@ namespace tools
     bool lock_keys_file();
     bool unlock_keys_file();
     bool is_keys_file_locked() const;
+
+    void change_password(const std::string &filename, const epee::wipeable_string &original_password, const epee::wipeable_string &new_password);
+
   private:
     /*!
      * \brief  Stores wallet information to wallet file.
@@ -1187,6 +1203,7 @@ namespace tools
     void generate_genesis(cryptonote::block& b) const;
     void check_genesis(const crypto::hash& genesis_hash) const; //throws
     bool generate_chacha_key_from_secret_keys(crypto::chacha_key &key) const;
+    void generate_chacha_key_from_password(const epee::wipeable_string &pass, crypto::chacha_key &key) const;
     crypto::hash get_payment_id(const pending_tx &ptx) const;
     void check_acc_out_precomp(const cryptonote::tx_out &o, const crypto::key_derivation &derivation, const std::vector<crypto::key_derivation> &additional_derivations, size_t i, tx_scan_info_t &tx_scan_info) const;
     void check_acc_out_precomp(const cryptonote::tx_out &o, const crypto::key_derivation &derivation, const std::vector<crypto::key_derivation> &additional_derivations, size_t i, const is_out_data *is_out_data, tx_scan_info_t &tx_scan_info) const;
@@ -1204,7 +1221,7 @@ namespace tools
     crypto::public_key get_tx_pub_key_from_received_outs(const tools::wallet2::transfer_details &td) const;
     bool should_pick_a_second_output(bool use_rct, size_t n_transfers, const std::vector<size_t> &unused_transfers_indices, const std::vector<size_t> &unused_dust_indices) const;
     std::vector<size_t> get_only_rct(const std::vector<size_t> &unused_dust_indices, const std::vector<size_t> &unused_transfers_indices) const;
-    void scan_output(const cryptonote::transaction &tx, const crypto::public_key &tx_pub_key, size_t i, tx_scan_info_t &tx_scan_info, int &num_vouts_received, std::unordered_map<cryptonote::subaddress_index, uint64_t> &tx_money_got_in_outs, std::vector<size_t> &outs) const;
+    void scan_output(const cryptonote::transaction &tx, const crypto::public_key &tx_pub_key, size_t i, tx_scan_info_t &tx_scan_info, int &num_vouts_received, std::unordered_map<cryptonote::subaddress_index, uint64_t> &tx_money_got_in_outs, std::vector<size_t> &outs);
     void trim_hashchain();
     crypto::key_image get_multisig_composite_key_image(size_t n) const;
     rct::multisig_kLRki get_multisig_composite_kLRki(size_t n, const crypto::public_key &ignore, std::unordered_set<rct::key> &used_L, std::unordered_set<rct::key> &new_used_L) const;
@@ -1216,8 +1233,7 @@ namespace tools
     bool remove_rings(const cryptonote::transaction_prefix &tx);
     bool get_ring(const crypto::chacha_key &key, const crypto::key_image &key_image, std::vector<uint64_t> &outs);
     crypto::chacha_key get_ringdb_key();
-    void cache_ringdb_key();
-    void clear_ringdb_key();
+    void setup_keys(const epee::wipeable_string &password);
 
     bool get_rct_distribution(uint64_t &start_height, std::vector<uint64_t> &distribution);
 
@@ -1320,6 +1336,11 @@ namespace tools
 
     uint64_t m_last_block_reward;
     std::unique_ptr<tools::file_locker> m_keys_file_locker;
+
+    crypto::chacha_key m_cache_key;
+    boost::optional<epee::wipeable_string> m_encrypt_keys_after_refresh;
+
+    bool m_rpc;
   };
 }
 BOOST_CLASS_VERSION(tools::wallet2, 25)
diff --git a/src/wallet/wallet_errors.h b/src/wallet/wallet_errors.h
index e80652750..243953280 100644
--- a/src/wallet/wallet_errors.h
+++ b/src/wallet/wallet_errors.h
@@ -53,6 +53,7 @@ namespace tools
     //         wallet_not_initialized
     //       multisig_export_needed
     //       multisig_import_needed
+    //       password_needed
     //   std::logic_error
     //     wallet_logic_error *
     //       file_exists
@@ -209,6 +210,14 @@ namespace tools
       }
     };
     //----------------------------------------------------------------------------------------------------
+    struct password_needed : public wallet_runtime_error
+    {
+      explicit password_needed(std::string&& loc, const std::string &msg = "Password needed")
+        : wallet_runtime_error(std::move(loc), msg)
+      {
+      }
+    };
+    //----------------------------------------------------------------------------------------------------
     const char* const file_error_messages[] = {
       "file already exists",
       "file not found",
diff --git a/src/wallet/wallet_rpc_server.cpp b/src/wallet/wallet_rpc_server.cpp
index 136cd0e2d..780f74d7f 100644
--- a/src/wallet/wallet_rpc_server.cpp
+++ b/src/wallet/wallet_rpc_server.cpp
@@ -163,7 +163,7 @@ namespace tools
       walvars = m_wallet;
     else
     {
-      tmpwal = tools::wallet2::make_dummy(*m_vm, password_prompter);
+      tmpwal = tools::wallet2::make_dummy(*m_vm, true, password_prompter);
       walvars = tmpwal.get();
     }
     boost::optional<epee::net_utils::http::login> http_login{};
@@ -2638,7 +2638,7 @@ namespace tools
       command_line::add_arg(desc, arg_password);
       po::store(po::parse_command_line(argc, argv, desc), vm2);
     }
-    std::unique_ptr<tools::wallet2> wal = tools::wallet2::make_new(vm2, nullptr).first;
+    std::unique_ptr<tools::wallet2> wal = tools::wallet2::make_new(vm2, true, nullptr).first;
     if (!wal)
     {
       er.code = WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR;
@@ -2712,7 +2712,7 @@ namespace tools
     }
     std::unique_ptr<tools::wallet2> wal = nullptr;
     try {
-      wal = tools::wallet2::make_from_file(vm2, wallet_file, nullptr).first;
+      wal = tools::wallet2::make_from_file(vm2, true, wallet_file, nullptr).first;
     }
     catch (const std::exception& e)
     {
@@ -3261,13 +3261,13 @@ int main(int argc, char** argv) {
     LOG_PRINT_L0(tools::wallet_rpc_server::tr("Loading wallet..."));
     if(!wallet_file.empty())
     {
-      wal = tools::wallet2::make_from_file(*vm, wallet_file, password_prompt).first;
+      wal = tools::wallet2::make_from_file(*vm, true, wallet_file, password_prompt).first;
     }
     else
     {
       try
       {
-        wal = tools::wallet2::make_from_json(*vm, from_json, password_prompt);
+        wal = tools::wallet2::make_from_json(*vm, true, from_json, password_prompt);
       }
       catch (const std::exception &e)
       {