17 files changed, 1342 insertions, 244 deletions

diff --git a/src/device_trezor/CMakeLists.txt b/src/device_trezor/CMakeLists.txt
index 7f979389a..250939da7 100644
--- a/src/device_trezor/CMakeLists.txt
+++ b/src/device_trezor/CMakeLists.txt
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2017, The Monero Project
+# Copyright (c) 2014-2019, The Monero Project
 #
 # All rights reserved.
 #
@@ -67,6 +67,12 @@ set(trezor_private_headers)
 if(DEVICE_TREZOR_READY)
     message(STATUS "Trezor support enabled")
 
+    if(USE_DEVICE_TREZOR_DEBUG)
+        list(APPEND trezor_headers trezor/debug_link.hpp trezor/messages/messages-debug.pb.h)
+        list(APPEND trezor_sources trezor/debug_link.cpp trezor/messages/messages-debug.pb.cc)
+        message(STATUS "Trezor debugging enabled")
+    endif()
+
     monero_private_headers(device_trezor
             ${device_private_headers})
 
diff --git a/src/device_trezor/device_trezor.cpp b/src/device_trezor/device_trezor.cpp
index 8868fb995..b4a80cf2c 100644
--- a/src/device_trezor/device_trezor.cpp
+++ b/src/device_trezor/device_trezor.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018, The Monero Project
+// Copyright (c) 2017-2019, The Monero Project
 //
 // All rights reserved.
 //
@@ -57,7 +57,9 @@ namespace trezor {
     }
 
     device_trezor::device_trezor() {
-
+      m_live_refresh_in_progress = false;
+      m_live_refresh_enabled = true;
+      m_live_refresh_thread_running = false;
     }
 
     device_trezor::~device_trezor() {
@@ -69,6 +71,89 @@ namespace trezor {
       }
     }
 
+    bool device_trezor::init()
+    {
+      m_live_refresh_in_progress = false;
+      bool r = device_trezor_base::init();
+      if (r && !m_live_refresh_thread)
+      {
+        m_live_refresh_thread_running = true;
+        m_live_refresh_thread.reset(new boost::thread(boost::bind(&device_trezor::live_refresh_thread_main, this)));
+      }
+      return r;
+    }
+
+    bool device_trezor::release()
+    {
+      m_live_refresh_in_progress = false;
+      m_live_refresh_thread_running = false;
+      if (m_live_refresh_thread)
+      {
+        m_live_refresh_thread->join();
+        m_live_refresh_thread = nullptr;
+      }
+      return device_trezor_base::release();
+    }
+
+    bool device_trezor::disconnect()
+    {
+      m_live_refresh_in_progress = false;
+      return device_trezor_base::disconnect();
+    }
+
+    void device_trezor::device_state_reset_unsafe()
+    {
+      require_connected();
+      if (m_live_refresh_in_progress)
+      {
+        try
+        {
+          live_refresh_finish_unsafe();
+        }
+        catch(const std::exception & e)
+        {
+          MERROR("Live refresh could not be terminated: " << e.what());
+        }
+      }
+
+      m_live_refresh_in_progress = false;
+      device_trezor_base::device_state_reset_unsafe();
+    }
+
+    void device_trezor::live_refresh_thread_main()
+    {
+      while(m_live_refresh_thread_running)
+      {
+        boost::this_thread::sleep_for(boost::chrono::milliseconds(100));
+        if (!m_live_refresh_in_progress)
+        {
+          continue;
+        }
+
+        TREZOR_AUTO_LOCK_DEVICE();
+        if (!m_transport || !m_live_refresh_in_progress)
+        {
+          continue;
+        }
+
+        auto current_time = std::chrono::steady_clock::now();
+        if (current_time - m_last_live_refresh_time <= std::chrono::seconds(20))
+        {
+          continue;
+        }
+
+        MTRACE("Closing live refresh process due to inactivity");
+        try
+        {
+          live_refresh_finish();
+        }
+        catch(const std::exception &e)
+        {
+          MWARNING("Live refresh auto-finish failed: " << e.what());
+        }
+      }
+    }
+
     /* ======================================================================= */
     /*                             WALLET & ADDRESS                            */
     /* ======================================================================= */
@@ -97,7 +182,14 @@ namespace trezor {
         auto res = get_view_key();
         CHECK_AND_ASSERT_MES(res->watch_key().size() == 32, false, "Trezor returned invalid view key");
 
+        // Trezor does not make use of spendkey of the device API.
+        // Ledger loads encrypted spendkey, Trezor loads null key (never leaves device).
+        // In the test (debugging mode) we need to leave this field intact as it is already set by
+        // the debugging code and need to remain same for the testing purposes.
+#ifndef WITH_TREZOR_DEBUGGING
         spendkey = crypto::null_skey; // not given
+#endif
+
         memcpy(viewkey.data, res->watch_key().data(), 32);
 
         return true;
@@ -119,7 +211,7 @@ namespace trezor {
     std::shared_ptr<messages::monero::MoneroAddress> device_trezor::get_address(
         const boost::optional<std::vector<uint32_t>> & path,
         const boost::optional<cryptonote::network_type> & network_type){
-      AUTO_LOCK_CMD();
+      TREZOR_AUTO_LOCK_CMD();
       require_connected();
       device_state_reset_unsafe();
       require_initialized();
@@ -135,7 +227,7 @@ namespace trezor {
     std::shared_ptr<messages::monero::MoneroWatchKey> device_trezor::get_view_key(
         const boost::optional<std::vector<uint32_t>> & path,
         const boost::optional<cryptonote::network_type> & network_type){
-      AUTO_LOCK_CMD();
+      TREZOR_AUTO_LOCK_CMD();
       require_connected();
       device_state_reset_unsafe();
       require_initialized();
@@ -148,11 +240,43 @@ namespace trezor {
       return response;
     }
 
+    bool device_trezor::is_get_tx_key_supported() const
+    {
+      require_initialized();
+      return get_version() > pack_version(2, 0, 10);
+    }
+
+    void device_trezor::load_tx_key_data(::hw::device_cold::tx_key_data_t & res, const std::string & tx_aux_data)
+    {
+      protocol::tx::load_tx_key_data(res, tx_aux_data);
+    }
+
+    void device_trezor::get_tx_key(
+        std::vector<::crypto::secret_key> & tx_keys,
+        const ::hw::device_cold::tx_key_data_t & tx_aux_data,
+        const ::crypto::secret_key & view_key_priv)
+    {
+      TREZOR_AUTO_LOCK_CMD();
+      require_connected();
+      device_state_reset_unsafe();
+      require_initialized();
+
+      auto req = protocol::tx::get_tx_key(tx_aux_data);
+      this->set_msg_addr<messages::monero::MoneroGetTxKeyRequest>(req.get());
+
+      auto response = this->client_exchange<messages::monero::MoneroGetTxKeyAck>(req);
+      MTRACE("Get TX key response received");
+
+      protocol::tx::get_tx_key_ack(tx_keys, tx_aux_data.tx_prefix_hash, view_key_priv, response);
+    }
+
     void device_trezor::ki_sync(wallet_shim * wallet,
                                 const std::vector<tools::wallet2::transfer_details> & transfers,
                                 hw::device_cold::exported_key_image & ski)
     {
-      AUTO_LOCK_CMD();
+#define EVENT_PROGRESS(P) do { if (m_callback) {(m_callback)->on_progress(device_cold::op_progress(P)); } }while(0)
+
+      TREZOR_AUTO_LOCK_CMD();
       require_connected();
       device_state_reset_unsafe();
       require_initialized();
@@ -164,6 +288,7 @@ namespace trezor {
       protocol::ki::key_image_data(wallet, transfers, mtds);
       protocol::ki::generate_commitment(mtds, transfers, req);
 
+      EVENT_PROGRESS(0.);
       this->set_msg_addr<messages::monero::MoneroKeyImageExportInitRequest>(req.get());
       auto ack1 = this->client_exchange<messages::monero::MoneroKeyImageExportInitAck>(req);
 
@@ -187,27 +312,160 @@ namespace trezor {
         }
 
         MTRACE("Batch " << cur << " / " << num_batches << " batches processed");
+        EVENT_PROGRESS((double)cur * batch_size / mtds.size());
       }
+      EVENT_PROGRESS(1.);
 
       auto final_req = std::make_shared<messages::monero::MoneroKeyImageSyncFinalRequest>();
       auto final_ack = this->client_exchange<messages::monero::MoneroKeyImageSyncFinalAck>(final_req);
       ski.reserve(kis.size());
 
       for(auto & sub : kis){
-        char buff[32*3];
+        ::crypto::signature sig{};
+        ::crypto::key_image ki;
+        char buff[sizeof(ki.data)*3];
+
+        size_t buff_len = sizeof(buff);
+
         protocol::crypto::chacha::decrypt(sub.blob().data(), sub.blob().size(),
                                           reinterpret_cast<const uint8_t *>(final_ack->enc_key().data()),
-                                          reinterpret_cast<const uint8_t *>(sub.iv().data()), buff);
+                                          reinterpret_cast<const uint8_t *>(sub.iv().data()), buff, &buff_len);
+        CHECK_AND_ASSERT_THROW_MES(buff_len == sizeof(buff), "Plaintext size invalid");
 
-        ::crypto::signature sig{};
-        ::crypto::key_image ki;
-        memcpy(ki.data, buff, 32);
-        memcpy(sig.c.data, buff + 32, 32);
-        memcpy(sig.r.data, buff + 64, 32);
+        memcpy(ki.data, buff, sizeof(ki.data));
+        memcpy(sig.c.data, buff + sizeof(ki.data), sizeof(ki.data));
+        memcpy(sig.r.data, buff + 2*sizeof(ki.data), sizeof(ki.data));
         ski.push_back(std::make_pair(ki, sig));
       }
+#undef EVENT_PROGRESS
+    }
+
+    bool device_trezor::is_live_refresh_supported() const
+    {
+      require_initialized();
+      return get_version() > pack_version(2, 0, 10);
     }
 
+    bool device_trezor::is_live_refresh_enabled() const
+    {
+      return is_live_refresh_supported() && (mode == NONE || mode == TRANSACTION_PARSE) && m_live_refresh_enabled;
+    }
+
+    bool device_trezor::has_ki_live_refresh() const
+    {
+      try{
+        return is_live_refresh_enabled();
+      } catch(const std::exception & e){
+        MERROR("Could not detect if live refresh is enabled: " << e.what());
+      }
+      return false;
+    }
+
+    void device_trezor::live_refresh_start()
+    {
+      TREZOR_AUTO_LOCK_CMD();
+      require_connected();
+      live_refresh_start_unsafe();
+    }
+
+    void device_trezor::live_refresh_start_unsafe()
+    {
+      device_state_reset_unsafe();
+      require_initialized();
+
+      auto req = std::make_shared<messages::monero::MoneroLiveRefreshStartRequest>();
+      this->set_msg_addr<messages::monero::MoneroLiveRefreshStartRequest>(req.get());
+      this->client_exchange<messages::monero::MoneroLiveRefreshStartAck>(req);
+      m_live_refresh_in_progress = true;
+      m_last_live_refresh_time = std::chrono::steady_clock::now();
+    }
+
+    void device_trezor::live_refresh(
+        const ::crypto::secret_key & view_key_priv,
+        const crypto::public_key& out_key,
+        const crypto::key_derivation& recv_derivation,
+        size_t real_output_index,
+        const cryptonote::subaddress_index& received_index,
+        cryptonote::keypair& in_ephemeral,
+        crypto::key_image& ki
+    )
+    {
+      TREZOR_AUTO_LOCK_CMD();
+      require_connected();
+
+      if (!m_live_refresh_in_progress)
+      {
+        live_refresh_start_unsafe();
+      }
+
+      m_last_live_refresh_time = std::chrono::steady_clock::now();
+
+      auto req = std::make_shared<messages::monero::MoneroLiveRefreshStepRequest>();
+      req->set_out_key(out_key.data, 32);
+      req->set_recv_deriv(recv_derivation.data, 32);
+      req->set_real_out_idx(real_output_index);
+      req->set_sub_addr_major(received_index.major);
+      req->set_sub_addr_minor(received_index.minor);
+
+      auto ack = this->client_exchange<messages::monero::MoneroLiveRefreshStepAck>(req);
+      protocol::ki::live_refresh_ack(view_key_priv, out_key, ack, in_ephemeral, ki);
+    }
+
+    void device_trezor::live_refresh_finish_unsafe()
+    {
+      auto req = std::make_shared<messages::monero::MoneroLiveRefreshFinalRequest>();
+      this->client_exchange<messages::monero::MoneroLiveRefreshFinalAck>(req);
+      m_live_refresh_in_progress = false;
+    }
+
+    void device_trezor::live_refresh_finish()
+    {
+      TREZOR_AUTO_LOCK_CMD();
+      require_connected();
+      if (m_live_refresh_in_progress)
+      {
+        live_refresh_finish_unsafe();
+      }
+    }
+
+    void device_trezor::computing_key_images(bool started)
+    {
+      try
+      {
+        if (!is_live_refresh_enabled())
+        {
+          return;
+        }
+
+        // React only on termination as the process can auto-start itself.
+        if (!started && m_live_refresh_in_progress)
+        {
+          live_refresh_finish();
+        }
+      }
+      catch(const std::exception & e)
+      {
+        MWARNING("KI computation state change failed, started: " << started << ", e: " << e.what());
+      }
+    }
+
+    bool device_trezor::compute_key_image(
+        const ::cryptonote::account_keys& ack,
+        const ::crypto::public_key& out_key,
+        const ::crypto::key_derivation& recv_derivation,
+        size_t real_output_index,
+        const ::cryptonote::subaddress_index& received_index,
+        ::cryptonote::keypair& in_ephemeral,
+        ::crypto::key_image& ki)
+    {
+      if (!is_live_refresh_enabled())
+      {
+        return false;
+      }
+
+      live_refresh(ack.m_view_secret_key, out_key, recv_derivation, real_output_index, received_index, in_ephemeral, ki);
+      return true;
+    }
 
     void device_trezor::tx_sign(wallet_shim * wallet,
                                 const tools::wallet2::unsigned_tx_set & unsigned_tx,
@@ -215,7 +473,15 @@ namespace trezor {
                                 hw::tx_aux_data & aux_data)
     {
       CHECK_AND_ASSERT_THROW_MES(unsigned_tx.transfers.first == 0, "Unsuported non zero offset");
-      size_t num_tx = unsigned_tx.txes.size();
+
+      TREZOR_AUTO_LOCK_CMD();
+      require_connected();
+      device_state_reset_unsafe();
+      require_initialized();
+      transaction_versions_check(unsigned_tx, aux_data);
+
+      const size_t num_tx = unsigned_tx.txes.size();
+      m_num_transations_to_sign = num_tx;
       signed_tx.key_images.clear();
       signed_tx.key_images.resize(unsigned_tx.transfers.second.size());
 
@@ -260,6 +526,10 @@ namespace trezor {
         cpend.key_images = key_images;
 
         // KI sync
+        for(size_t cidx=0, trans_max=unsigned_tx.transfers.second.size(); cidx < trans_max; ++cidx){
+          signed_tx.key_images[cidx] = unsigned_tx.transfers.second[cidx].m_key_image;
+        }
+
         size_t num_sources = cdata.tx_data.sources.size();
         CHECK_AND_ASSERT_THROW_MES(num_sources == cdata.source_permutation.size(), "Invalid permutation size");
         CHECK_AND_ASSERT_THROW_MES(num_sources == cdata.tx.vin.size(), "Invalid tx.vin size");
@@ -269,12 +539,19 @@ namespace trezor {
           CHECK_AND_ASSERT_THROW_MES(src_idx < cdata.tx.vin.size(), "Invalid idx_mapped");
 
           size_t idx_map_src = cdata.tx_data.selected_transfers[idx_mapped];
-          auto vini = boost::get<cryptonote::txin_to_key>(cdata.tx.vin[src_idx]);
+          CHECK_AND_ASSERT_THROW_MES(idx_map_src >= unsigned_tx.transfers.first, "Invalid offset");
 
+          idx_map_src -= unsigned_tx.transfers.first;
           CHECK_AND_ASSERT_THROW_MES(idx_map_src < signed_tx.key_images.size(), "Invalid key image index");
+
+          const auto vini = boost::get<cryptonote::txin_to_key>(cdata.tx.vin[src_idx]);
           signed_tx.key_images[idx_map_src] = vini.k_image;
         }
       }
+
+      if (m_callback){
+        m_callback->on_progress(device_cold::tx_progress(m_num_transations_to_sign, m_num_transations_to_sign, 1, 1, 1, 1));
+      }
     }
 
     void device_trezor::tx_sign(wallet_shim * wallet,
@@ -283,10 +560,16 @@ namespace trezor {
                    hw::tx_aux_data & aux_data,
                    std::shared_ptr<protocol::tx::Signer> & signer)
     {
-      AUTO_LOCK_CMD();
+#define EVENT_PROGRESS(S, SUB, SUBMAX) do { if (m_callback) { \
+      (m_callback)->on_progress(device_cold::tx_progress(idx, m_num_transations_to_sign, S, 10, SUB, SUBMAX)); \
+} }while(0)
+
       require_connected();
-      device_state_reset_unsafe();
+      if (idx > 0)
+        device_state_reset_unsafe();
+
       require_initialized();
+      EVENT_PROGRESS(0, 1, 1);
 
       CHECK_AND_ASSERT_THROW_MES(idx < unsigned_tx.txes.size(), "Invalid transaction index");
       signer = std::make_shared<protocol::tx::Signer>(wallet, &unsigned_tx, idx, &aux_data);
@@ -298,6 +581,7 @@ namespace trezor {
       auto init_msg = signer->step_init();
       this->set_msg_addr(init_msg.get());
       transaction_pre_check(init_msg);
+      EVENT_PROGRESS(1, 1, 1);
 
       auto response = this->client_exchange<messages::monero::MoneroTransactionInitAck>(init_msg);
       signer->step_init_ack(response);
@@ -307,6 +591,7 @@ namespace trezor {
         auto src = signer->step_set_input(cur_src);
         auto ack = this->client_exchange<messages::monero::MoneroTransactionSetInputAck>(src);
         signer->step_set_input_ack(ack);
+        EVENT_PROGRESS(2, cur_src, num_sources);
       }
 
       // Step: sort
@@ -315,44 +600,82 @@ namespace trezor {
         auto perm_ack = this->client_exchange<messages::monero::MoneroTransactionInputsPermutationAck>(perm_req);
         signer->step_permutation_ack(perm_ack);
       }
+      EVENT_PROGRESS(3, 1, 1);
 
       // Step: input_vini
-      if (!signer->in_memory()){
-        for(size_t cur_src = 0; cur_src < num_sources; ++cur_src){
-          auto src = signer->step_set_vini_input(cur_src);
-          auto ack = this->client_exchange<messages::monero::MoneroTransactionInputViniAck>(src);
-          signer->step_set_vini_input_ack(ack);
-        }
+      for(size_t cur_src = 0; cur_src < num_sources; ++cur_src){
+        auto src = signer->step_set_vini_input(cur_src);
+        auto ack = this->client_exchange<messages::monero::MoneroTransactionInputViniAck>(src);
+        signer->step_set_vini_input_ack(ack);
+        EVENT_PROGRESS(4, cur_src, num_sources);
       }
 
       // Step: all inputs set
       auto all_inputs_set = signer->step_all_inputs_set();
       auto ack_all_inputs = this->client_exchange<messages::monero::MoneroTransactionAllInputsSetAck>(all_inputs_set);
       signer->step_all_inputs_set_ack(ack_all_inputs);
+      EVENT_PROGRESS(5, 1, 1);
 
       // Step: outputs
       for(size_t cur_dst = 0; cur_dst < num_outputs; ++cur_dst){
         auto src = signer->step_set_output(cur_dst);
         auto ack = this->client_exchange<messages::monero::MoneroTransactionSetOutputAck>(src);
         signer->step_set_output_ack(ack);
+
+        // If BP is offloaded to host, another step with computed BP may be needed.
+        auto offloaded_bp = signer->step_rsig(cur_dst);
+        if (offloaded_bp){
+          auto bp_ack = this->client_exchange<messages::monero::MoneroTransactionSetOutputAck>(offloaded_bp);
+          signer->step_set_rsig_ack(ack);
+        }
+
+        EVENT_PROGRESS(6, cur_dst, num_outputs);
       }
 
       // Step: all outs set
       auto all_out_set = signer->step_all_outs_set();
       auto ack_all_out_set = this->client_exchange<messages::monero::MoneroTransactionAllOutSetAck>(all_out_set);
       signer->step_all_outs_set_ack(ack_all_out_set, *this);
+      EVENT_PROGRESS(7, 1, 1);
 
       // Step: sign each input
       for(size_t cur_src = 0; cur_src < num_sources; ++cur_src){
         auto src = signer->step_sign_input(cur_src);
         auto ack_sign = this->client_exchange<messages::monero::MoneroTransactionSignInputAck>(src);
         signer->step_sign_input_ack(ack_sign);
+        EVENT_PROGRESS(8, cur_src, num_sources);
       }
 
       // Step: final
       auto final_msg = signer->step_final();
       auto ack_final = this->client_exchange<messages::monero::MoneroTransactionFinalAck>(final_msg);
       signer->step_final_ack(ack_final);
+      EVENT_PROGRESS(9, 1, 1);
+#undef EVENT_PROGRESS
+    }
+
+    void device_trezor::transaction_versions_check(const ::tools::wallet2::unsigned_tx_set & unsigned_tx, hw::tx_aux_data & aux_data)
+    {
+      auto trezor_version = get_version();
+      unsigned client_version = 1;  // default client version for tx
+
+      if (trezor_version <= pack_version(2, 0, 10)){
+        client_version = 0;
+      }
+
+      if (aux_data.client_version){
+        auto wanted_client_version = aux_data.client_version.get();
+        if (wanted_client_version > client_version){
+          throw exc::TrezorException("Trezor firmware 2.0.10 and lower does not support current transaction sign protocol. Please update.");
+        } else {
+          client_version = wanted_client_version;
+        }
+      }
+      aux_data.client_version = client_version;
+
+      if (client_version == 0 && aux_data.bp_version && aux_data.bp_version.get() != 1){
+        throw exc::TrezorException("Trezor firmware 2.0.10 and lower does not support current transaction sign protocol (BPv2+). Please update.");
+      }
     }
 
     void device_trezor::transaction_pre_check(std::shared_ptr<messages::monero::MoneroTransactionInitRequest> init_msg)
@@ -362,13 +685,9 @@ namespace trezor {
       CHECK_AND_ASSERT_THROW_MES(m_features, "Device state not initialized");  // make sure the caller did not reset features
       const bool nonce_required = init_msg->tsx_data().has_payment_id() && init_msg->tsx_data().payment_id().size() > 0;
 
-      if (nonce_required){
+      if (nonce_required && init_msg->tsx_data().payment_id().size() == 8){
         // Versions 2.0.9 and lower do not support payment ID
-        CHECK_AND_ASSERT_THROW_MES(m_features->has_major_version() && m_features->has_minor_version() && m_features->has_patch_version(), "Invalid Trezor firmware version information");
-        const uint32_t vma = m_features->major_version();
-        const uint32_t vmi = m_features->minor_version();
-        const uint32_t vpa = m_features->patch_version();
-        if (vma < 2 || (vma == 2 && vmi == 0 && vpa <= 9)) {
+        if (get_version() <= pack_version(2, 0, 9)) {
           throw exc::TrezorException("Trezor firmware 2.0.9 and lower does not support transactions with short payment IDs or integrated addresses. Please update.");
         }
       }
@@ -393,7 +712,7 @@ namespace trezor {
 
       const bool nonce_required = tdata.tsx_data.has_payment_id() && tdata.tsx_data.payment_id().size() > 0;
       const bool has_nonce = cryptonote::find_tx_extra_field_by_type(tx_extra_fields, nonce);
-      CHECK_AND_ASSERT_THROW_MES(has_nonce == nonce_required, "Transaction nonce presence inconsistent");
+      CHECK_AND_ASSERT_THROW_MES(has_nonce || !nonce_required, "Transaction nonce not present");
 
       if (nonce_required){
         const std::string & payment_id = tdata.tsx_data.payment_id();
diff --git a/src/device_trezor/device_trezor.hpp b/src/device_trezor/device_trezor.hpp
index 1f08be887..0e91847dc 100644
--- a/src/device_trezor/device_trezor.hpp
+++ b/src/device_trezor/device_trezor.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018, The Monero Project
+// Copyright (c) 2017-2019, The Monero Project
 //
 // All rights reserved.
 //
@@ -30,18 +30,21 @@
 #ifndef MONERO_DEVICE_TREZOR_H
 #define MONERO_DEVICE_TREZOR_H
 
+#include "trezor.hpp"
+#include "device/device.hpp"
 
+#ifdef WITH_DEVICE_TREZOR
 #include <cstddef>
 #include <string>
-#include "device/device.hpp"
-#include "device/device_default.hpp"
-#include "device/device_cold.hpp"
 #include <boost/scope_exit.hpp>
 #include <boost/thread/mutex.hpp>
 #include <boost/thread/recursive_mutex.hpp>
+
+#include "device/device_default.hpp"
+#include "device/device_cold.hpp"
 #include "cryptonote_config.h"
-#include "trezor.hpp"
 #include "device_trezor_base.hpp"
+#endif
 
 namespace hw {
 namespace trezor {
@@ -57,8 +60,29 @@ namespace trezor {
    */
   class device_trezor : public hw::trezor::device_trezor_base, public hw::device_cold {
     protected:
+      std::atomic<bool> m_live_refresh_in_progress;
+      std::chrono::steady_clock::time_point m_last_live_refresh_time;
+      std::unique_ptr<boost::thread> m_live_refresh_thread;
+      std::atomic<bool> m_live_refresh_thread_running;
+      bool m_live_refresh_enabled;
+      size_t m_num_transations_to_sign;
+
+      void transaction_versions_check(const ::tools::wallet2::unsigned_tx_set & unsigned_tx, hw::tx_aux_data & aux_data);
       void transaction_pre_check(std::shared_ptr<messages::monero::MoneroTransactionInitRequest> init_msg);
       void transaction_check(const protocol::tx::TData & tdata, const hw::tx_aux_data & aux_data);
+      void device_state_reset_unsafe() override;
+      void live_refresh_start_unsafe();
+      void live_refresh_finish_unsafe();
+      void live_refresh_thread_main();
+
+      /**
+       * Signs particular transaction idx in the unsigned set, keeps state in the signer
+       */
+      virtual void tx_sign(wallet_shim * wallet,
+                   const ::tools::wallet2::unsigned_tx_set & unsigned_tx,
+                   size_t idx,
+                   hw::tx_aux_data & aux_data,
+                   std::shared_ptr<protocol::tx::Signer> & signer);
 
     public:
       device_trezor();
@@ -69,11 +93,17 @@ namespace trezor {
 
       explicit operator bool() const override {return true;}
 
+      bool init() override;
+      bool release() override;
+      bool disconnect() override;
+
       device_protocol_t device_protocol() const override { return PROTOCOL_COLD; };
 
       bool  has_ki_cold_sync() const override { return true; }
       bool  has_tx_cold_sign() const override { return true; }
       void  set_network_type(cryptonote::network_type network_type) override { this->network_type = network_type; }
+      void  set_live_refresh_enabled(bool enabled) { m_live_refresh_enabled = enabled; }
+      bool  live_refresh_enabled() const { return m_live_refresh_enabled; }
 
       /* ======================================================================= */
       /*                             WALLET & ADDRESS                            */
@@ -100,20 +130,68 @@ namespace trezor {
           const boost::optional<cryptonote::network_type> & network_type = boost::none);
 
       /**
+       * Get_tx_key support check
+       */
+      bool is_get_tx_key_supported() const override;
+
+      /**
+       * Loads tx aux data
+       */
+      void load_tx_key_data(::hw::device_cold::tx_key_data_t & res, const std::string & tx_aux_data) override;
+
+      /**
+       * TX key load with the Trezor
+       */
+      void get_tx_key(
+        std::vector<::crypto::secret_key> & tx_keys,
+        const ::hw::device_cold::tx_key_data_t & tx_aux_data,
+        const ::crypto::secret_key & view_key_priv) override;
+
+      /**
        * Key image sync with the Trezor.
        */
       void ki_sync(wallet_shim * wallet,
                    const std::vector<::tools::wallet2::transfer_details> & transfers,
                    hw::device_cold::exported_key_image & ski) override;
 
+      bool is_live_refresh_supported() const override;
+
+      bool is_live_refresh_enabled() const;
+
+      bool has_ki_live_refresh() const override;
+
+      void live_refresh_start() override;
+
+      void live_refresh(
+          const ::crypto::secret_key & view_key_priv,
+          const crypto::public_key& out_key,
+          const crypto::key_derivation& recv_derivation,
+          size_t real_output_index,
+          const cryptonote::subaddress_index& received_index,
+          cryptonote::keypair& in_ephemeral,
+          crypto::key_image& ki
+          ) override;
+
+      void live_refresh_finish() override;
+
       /**
-       * Signs particular transaction idx in the unsigned set, keeps state in the signer
+       * Letting device know the KI computation started / ended.
+       * During refresh
        */
-      void tx_sign(wallet_shim * wallet,
-                   const ::tools::wallet2::unsigned_tx_set & unsigned_tx,
-                   size_t idx,
-                   hw::tx_aux_data & aux_data,
-                   std::shared_ptr<protocol::tx::Signer> & signer);
+      void computing_key_images(bool started) override;
+
+      /**
+       * Implements hw::device interface
+       * called from generate_key_image_helper_precomp()
+       */
+      bool compute_key_image(
+          const ::cryptonote::account_keys& ack,
+          const ::crypto::public_key& out_key,
+          const ::crypto::key_derivation& recv_derivation,
+          size_t real_output_index,
+          const ::cryptonote::subaddress_index& received_index,
+          ::cryptonote::keypair& in_ephemeral,
+          ::crypto::key_image& ki) override;
 
       /**
        * Signs unsigned transaction with the Trezor.
diff --git a/src/device_trezor/device_trezor_base.cpp b/src/device_trezor/device_trezor_base.cpp
index 5071932ee..f3d15c5e2 100644
--- a/src/device_trezor/device_trezor_base.cpp
+++ b/src/device_trezor/device_trezor_base.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018, The Monero Project
+// Copyright (c) 2017-2019, The Monero Project
 //
 // All rights reserved.
 //
@@ -44,7 +44,9 @@ namespace trezor {
     const uint32_t device_trezor_base::DEFAULT_BIP44_PATH[] = {0x8000002c, 0x80000080};
 
     device_trezor_base::device_trezor_base(): m_callback(nullptr) {
-
+#ifdef WITH_TREZOR_DEBUGGING
+      m_debug = false;
+#endif
     }
 
     device_trezor_base::~device_trezor_base() {
@@ -107,6 +109,7 @@ namespace trezor {
       disconnect();
 
       // Enumerate all available devices
+      TREZOR_AUTO_LOCK_DEVICE();
       try {
         hw::trezor::t_transport_vect trans;
 
@@ -130,6 +133,10 @@ namespace trezor {
         }
 
         m_transport->open();
+
+#ifdef WITH_TREZOR_DEBUGGING
+        setup_debug();
+#endif
         return true;
 
       } catch(std::exception const& e){
@@ -139,6 +146,7 @@ namespace trezor {
     }
 
     bool device_trezor_base::disconnect() {
+      TREZOR_AUTO_LOCK_DEVICE();
       m_device_state.clear();
       m_features.reset();
 
@@ -153,6 +161,13 @@ namespace trezor {
           return false;
         }
       }
+
+#ifdef WITH_TREZOR_DEBUGGING
+      if (m_debug_callback) {
+        m_debug_callback->on_disconnect();
+        m_debug_callback = nullptr;
+      }
+#endif
       return true;
     }
 
@@ -190,13 +205,13 @@ namespace trezor {
     /*  Helpers                                                                */
     /* ======================================================================= */
 
-    void device_trezor_base::require_connected(){
+    void device_trezor_base::require_connected() const {
       if (!m_transport){
         throw exc::NotConnectedException();
       }
     }
 
-    void device_trezor_base::require_initialized(){
+    void device_trezor_base::require_initialized() const {
       if (!m_features){
         throw exc::TrezorException("Device state not initialized");
       }
@@ -317,7 +332,7 @@ namespace trezor {
     /* ======================================================================= */
 
     bool device_trezor_base::ping() {
-      AUTO_LOCK_CMD();
+      TREZOR_AUTO_LOCK_CMD();
       if (!m_transport){
         MINFO("Ping failed, device not connected");
         return false;
@@ -351,10 +366,41 @@ namespace trezor {
 
     void device_trezor_base::device_state_reset()
     {
-      AUTO_LOCK_CMD();
+      TREZOR_AUTO_LOCK_CMD();
       device_state_reset_unsafe();
     }
 
+#ifdef WITH_TREZOR_DEBUGGING
+#define TREZOR_CALLBACK(method, ...) do { \
+  if (m_debug_callback) m_debug_callback->method(__VA_ARGS__); \
+  if (m_callback) m_callback->method(__VA_ARGS__);             \
+}while(0)
+#define TREZOR_CALLBACK_GET(VAR, method, ...) do { \
+  if (m_debug_callback) VAR = m_debug_callback->method(__VA_ARGS__); \
+  if (m_callback) VAR = m_callback->method(__VA_ARGS__);             \
+}while(0)
+
+    void device_trezor_base::setup_debug(){
+      if (!m_debug){
+        return;
+      }
+
+      if (!m_debug_callback){
+        CHECK_AND_ASSERT_THROW_MES(m_transport, "Transport does not exist");
+        auto debug_transport = m_transport->find_debug();
+        if (debug_transport) {
+          m_debug_callback = std::make_shared<trezor_debug_callback>(debug_transport);
+        } else {
+          MDEBUG("Transport does not have debug link option");
+        }
+      }
+    }
+
+#else
+#define TREZOR_CALLBACK(method, ...) do { if (m_callback) m_callback->method(__VA_ARGS__); } while(0)
+#define TREZOR_CALLBACK_GET(VAR, method, ...) VAR = (m_callback ? m_callback->method(__VA_ARGS__) : boost::none)
+#endif
+
     void device_trezor_base::on_button_request(GenericMessage & resp, const messages::common::ButtonRequest * msg)
     {
       CHECK_AND_ASSERT_THROW_MES(msg, "Empty message");
@@ -363,10 +409,7 @@ namespace trezor {
       messages::common::ButtonAck ack;
       write_raw(&ack);
 
-      if (m_callback){
-        m_callback->on_button_request();
-      }
-
+      TREZOR_CALLBACK(on_button_request, msg->code());
       resp = read_raw();
     }
 
@@ -375,15 +418,18 @@ namespace trezor {
       MDEBUG("on_pin_request");
       CHECK_AND_ASSERT_THROW_MES(msg, "Empty message");
 
-      epee::wipeable_string pin;
+      boost::optional<epee::wipeable_string> pin;
+      TREZOR_CALLBACK_GET(pin, on_pin_request);
 
-      if (m_callback){
-        m_callback->on_pin_request(pin);
+      if (!pin && m_pin){
+        pin = m_pin;
       }
 
       // TODO: remove PIN from memory
       messages::common::PinMatrixAck m;
-      m.set_pin(pin.data(), pin.size());
+      if (pin) {
+        m.set_pin(pin.get().data(), pin.get().size());
+      }
       resp = call_raw(&m);
     }
 
@@ -391,16 +437,19 @@ namespace trezor {
     {
       CHECK_AND_ASSERT_THROW_MES(msg, "Empty message");
       MDEBUG("on_passhprase_request, on device: " << msg->on_device());
-      epee::wipeable_string passphrase;
+      boost::optional<epee::wipeable_string> passphrase;
+      TREZOR_CALLBACK_GET(passphrase, on_passphrase_request, msg->on_device());
 
-      if (m_callback){
-        m_callback->on_passphrase_request(msg->on_device(), passphrase);
+      if (!passphrase && m_passphrase){
+        passphrase = m_passphrase;
       }
 
+      m_passphrase = boost::none;
+
       messages::common::PassphraseAck m;
-      if (!msg->on_device()){
+      if (!msg->on_device() && passphrase){
         // TODO: remove passphrase from memory
-        m.set_passphrase(passphrase.data(), passphrase.size());
+        m.set_passphrase(passphrase.get().data(), passphrase.get().size());
       }
 
       if (!m_device_state.empty()){
@@ -421,5 +470,67 @@ namespace trezor {
       resp = call_raw(&m);
     }
 
+#ifdef WITH_TREZOR_DEBUGGING
+    void device_trezor_base::wipe_device()
+    {
+      auto msg = std::make_shared<messages::management::WipeDevice>();
+      auto ret = client_exchange<messages::common::Success>(msg);
+      (void)ret;
+      init_device();
+    }
+
+    void device_trezor_base::init_device()
+    {
+      auto msg = std::make_shared<messages::management::Initialize>();
+      m_features = client_exchange<messages::management::Features>(msg);
+    }
+
+    void device_trezor_base::load_device(const std::string & mnemonic, const std::string & pin,
+        bool passphrase_protection, const std::string & label, const std::string & language,
+        bool skip_checksum, bool expand)
+    {
+      if (m_features && m_features->initialized()){
+        throw std::runtime_error("Device is initialized already. Call device.wipe() and try again.");
+      }
+
+      auto msg = std::make_shared<messages::management::LoadDevice>();
+      msg->set_mnemonic(mnemonic);
+      msg->set_pin(pin);
+      msg->set_passphrase_protection(passphrase_protection);
+      msg->set_label(label);
+      msg->set_language(language);
+      msg->set_skip_checksum(skip_checksum);
+      auto ret = client_exchange<messages::common::Success>(msg);
+      (void)ret;
+
+      init_device();
+    }
+
+    trezor_debug_callback::trezor_debug_callback(std::shared_ptr<Transport> & debug_transport){
+      m_debug_link = std::make_shared<DebugLink>();
+      m_debug_link->init(debug_transport);
+    }
+
+    void trezor_debug_callback::on_button_request(uint64_t code) {
+      if (m_debug_link) m_debug_link->press_yes();
+    }
+
+    boost::optional<epee::wipeable_string> trezor_debug_callback::on_pin_request() {
+      return boost::none;
+    }
+
+    boost::optional<epee::wipeable_string> trezor_debug_callback::on_passphrase_request(bool on_device) {
+      return boost::none;
+    }
+
+    void trezor_debug_callback::on_passphrase_state_request(const std::string &state) {
+
+    }
+
+    void trezor_debug_callback::on_disconnect(){
+      if (m_debug_link) m_debug_link->close();
+    }
+#endif
+
 #endif //WITH_DEVICE_TREZOR
 }}
diff --git a/src/device_trezor/device_trezor_base.hpp b/src/device_trezor/device_trezor_base.hpp
index 3c35e8aca..8c3c14b29 100644
--- a/src/device_trezor/device_trezor_base.hpp
+++ b/src/device_trezor/device_trezor_base.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018, The Monero Project
+// Copyright (c) 2017-2019, The Monero Project
 //
 // All rights reserved.
 //
@@ -42,21 +42,43 @@
 #include "cryptonote_config.h"
 #include "trezor.hpp"
 
+#ifdef WITH_TREZOR_DEBUGGING
+#include "trezor/debug_link.hpp"
+#endif
+
 //automatic lock one more level on device ensuring the current thread is allowed to use it
-#define AUTO_LOCK_CMD() \
+#define TREZOR_AUTO_LOCK_CMD() \
   /* lock both mutexes without deadlock*/ \
   boost::lock(device_locker, command_locker); \
   /* make sure both already-locked mutexes are unlocked at the end of scope */ \
   boost::lock_guard<boost::recursive_mutex> lock1(device_locker, boost::adopt_lock); \
   boost::lock_guard<boost::mutex> lock2(command_locker, boost::adopt_lock)
 
-  
+#define TREZOR_AUTO_LOCK_DEVICE() boost::lock_guard<boost::recursive_mutex> lock1_device(device_locker)
+
 namespace hw {
 namespace trezor {
 
 #ifdef WITH_DEVICE_TREZOR
   class device_trezor_base;
 
+#ifdef WITH_TREZOR_DEBUGGING
+    class trezor_debug_callback : public hw::i_device_callback {
+    public:
+      trezor_debug_callback()=default;
+      explicit trezor_debug_callback(std::shared_ptr<Transport> & debug_transport);
+
+      void on_button_request(uint64_t code=0) override;
+      boost::optional<epee::wipeable_string> on_pin_request() override;
+      boost::optional<epee::wipeable_string> on_passphrase_request(bool on_device) override;
+      void on_passphrase_state_request(const std::string &state);
+      void on_disconnect();
+    protected:
+      std::shared_ptr<DebugLink> m_debug_link;
+    };
+
+#endif
+
   /**
    * TREZOR device template with basic functions
    */
@@ -74,18 +96,27 @@ namespace trezor {
       std::vector<unsigned int> m_wallet_deriv_path;
       std::string m_device_state;  // returned after passphrase entry, session
       std::shared_ptr<messages::management::Features> m_features;  // features from the last device reset
+      boost::optional<epee::wipeable_string> m_pin;
+      boost::optional<epee::wipeable_string> m_passphrase;
 
       cryptonote::network_type network_type;
 
+#ifdef WITH_TREZOR_DEBUGGING
+      std::shared_ptr<trezor_debug_callback> m_debug_callback;
+      bool m_debug;
+
+      void setup_debug();
+#endif
+
       //
       // Internal methods
       //
 
-      void require_connected();
-      void require_initialized();
+      void require_connected() const;
+      void require_initialized() const;
       void call_ping_unsafe();
       void test_ping();
-      void device_state_reset_unsafe();
+      virtual void device_state_reset_unsafe();
       void ensure_derivation_path() noexcept;
 
       // Communication methods
@@ -103,7 +134,7 @@ namespace trezor {
        * @throws UnexpectedMessageException if the response message type is different than expected.
        * Exception contains message type and the message itself.
        */
-      template<class t_message>
+      template<class t_message=google::protobuf::Message>
       std::shared_ptr<t_message>
       client_exchange(const std::shared_ptr<const google::protobuf::Message> &req,
                       const boost::optional<messages::MessageType> & resp_type = boost::none,
@@ -229,8 +260,23 @@ namespace trezor {
       return m_features;
     }
 
+    uint64_t get_version() const {
+      CHECK_AND_ASSERT_THROW_MES(m_features, "Features not loaded");
+      CHECK_AND_ASSERT_THROW_MES(m_features->has_major_version() && m_features->has_minor_version() && m_features->has_patch_version(), "Invalid Trezor firmware version information");
+      return pack_version(m_features->major_version(), m_features->minor_version(), m_features->patch_version());
+    }
+
     void set_derivation_path(const std::string &deriv_path) override;
 
+    virtual bool has_ki_live_refresh(void) const override { return false; }
+
+    virtual void set_pin(const epee::wipeable_string & pin) override {
+      m_pin = pin;
+    }
+    virtual void set_passphrase(const epee::wipeable_string & passphrase) override {
+      m_passphrase = passphrase;
+    }
+
     /* ======================================================================= */
     /*                              SETUP/TEARDOWN                             */
     /* ======================================================================= */
@@ -268,6 +314,23 @@ namespace trezor {
     void on_pin_request(GenericMessage & resp, const messages::common::PinMatrixRequest * msg);
     void on_passphrase_request(GenericMessage & resp, const messages::common::PassphraseRequest * msg);
     void on_passphrase_state_request(GenericMessage & resp, const messages::common::PassphraseStateRequest * msg);
+
+#ifdef WITH_TREZOR_DEBUGGING
+    void set_debug(bool debug){
+      m_debug = debug;
+    }
+
+    void set_debug_callback(std::shared_ptr<trezor_debug_callback> & debug_callback){
+      m_debug_callback = debug_callback;
+    }
+
+    void wipe_device();
+    void init_device();
+    void load_device(const std::string & mnemonic, const std::string & pin="", bool passphrase_protection=false,
+        const std::string & label="test", const std::string & language="english",
+        bool skip_checksum=false, bool expand=false);
+
+#endif
   };
 
 #endif
diff --git a/src/device_trezor/trezor.hpp b/src/device_trezor/trezor.hpp
index 97dc0a957..396a27534 100644
--- a/src/device_trezor/trezor.hpp
+++ b/src/device_trezor/trezor.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018, The Monero Project
+// Copyright (c) 2017-2019, The Monero Project
 //
 // All rights reserved.
 //
diff --git a/src/device_trezor/trezor/debug_link.cpp b/src/device_trezor/trezor/debug_link.cpp
new file mode 100644
index 000000000..c7ee59afe
--- /dev/null
+++ b/src/device_trezor/trezor/debug_link.cpp
@@ -0,0 +1,90 @@
+// Copyright (c) 2017-2018, 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.
+//
+
+#include "debug_link.hpp"
+
+namespace hw{
+namespace trezor{
+
+  DebugLink::DebugLink(){
+
+  }
+
+  DebugLink::~DebugLink(){
+    if (m_transport){
+      close();
+    }
+  }
+
+  void DebugLink::init(std::shared_ptr<Transport> & transport){
+    CHECK_AND_ASSERT_THROW_MES(!m_transport, "Already initialized");
+    m_transport = transport;
+    m_transport->open();
+  }
+
+  void DebugLink::close(){
+    CHECK_AND_ASSERT_THROW_MES(m_transport, "Not initialized");
+    if (m_transport) m_transport->close();
+  }
+
+  std::shared_ptr<messages::debug::DebugLinkState> DebugLink::state(){
+    return call<messages::debug::DebugLinkState>(
+        messages::debug::DebugLinkGetState(),
+        boost::make_optional(messages::MessageType_DebugLinkGetState));
+  }
+
+  void DebugLink::input_word(const std::string & word){
+    messages::debug::DebugLinkDecision decision;
+    decision.set_input(word);
+    call(decision, boost::none, true);
+  }
+
+  void DebugLink::input_button(bool button){
+    messages::debug::DebugLinkDecision decision;
+    decision.set_yes_no(button);
+    call(decision, boost::none, true);
+  }
+
+  void DebugLink::input_swipe(bool swipe){
+    messages::debug::DebugLinkDecision decision;
+    decision.set_up_down(swipe);
+    call(decision, boost::none, true);
+  }
+
+  void DebugLink::stop(){
+    messages::debug::DebugLinkStop msg;
+    call(msg, boost::none, true);
+  }
+
+
+
+
+
+}
+}
\ No newline at end of file
diff --git a/src/device_trezor/trezor/debug_link.hpp b/src/device_trezor/trezor/debug_link.hpp
new file mode 100644
index 000000000..adf5f1d8f
--- /dev/null
+++ b/src/device_trezor/trezor/debug_link.hpp
@@ -0,0 +1,93 @@
+// Copyright (c) 2017-2018, 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.
+//
+
+#ifndef MONERO_DEBUG_LINK_H
+#define MONERO_DEBUG_LINK_H
+
+#include "transport.hpp"
+#include "messages/messages-debug.pb.h"
+
+
+namespace hw {
+namespace trezor {
+
+  class DebugLink {
+  public:
+
+    DebugLink();
+    virtual ~DebugLink();
+
+    void init(std::shared_ptr<Transport> & transport);
+    void close();
+
+    std::shared_ptr<messages::debug::DebugLinkState> state();
+    void input_word(const std::string & word);
+    void input_button(bool button);
+    void input_swipe(bool swipe);
+    void press_yes() { input_button(true); }
+    void press_no() { input_button(false); }
+    void stop();
+
+    template<class t_message=messages::debug::DebugLinkState>
+    std::shared_ptr<t_message> call(
+        const google::protobuf::Message & req,
+        const boost::optional<messages::MessageType> &resp_type = boost::none,
+        bool no_wait = false)
+    {
+      BOOST_STATIC_ASSERT(boost::is_base_of<google::protobuf::Message, t_message>::value);
+
+      m_transport->write(req);
+      if (no_wait){
+        return nullptr;
+      }
+
+      // Read the response
+      std::shared_ptr<google::protobuf::Message> msg_resp;
+      hw::trezor::messages::MessageType msg_resp_type;
+      m_transport->read(msg_resp, &msg_resp_type);
+
+      messages::MessageType required_type = resp_type ? resp_type.get() : MessageMapper::get_message_wire_number<t_message>();
+      if (msg_resp_type == required_type) {
+        return message_ptr_retype<t_message>(msg_resp);
+      } else if (msg_resp_type == messages::MessageType_Failure){
+        throw_failure_exception(dynamic_cast<messages::common::Failure*>(msg_resp.get()));
+      } else {
+        throw exc::UnexpectedMessageException(msg_resp_type, msg_resp);
+      }
+    };
+
+  private:
+    std::shared_ptr<Transport> m_transport;
+
+  };
+
+}
+}
+
+#endif //MONERO_DEBUG_LINK_H
diff --git a/src/device_trezor/trezor/exceptions.hpp b/src/device_trezor/trezor/exceptions.hpp
index 197dc43a4..41e8c2875 100644
--- a/src/device_trezor/trezor/exceptions.hpp
+++ b/src/device_trezor/trezor/exceptions.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018, The Monero Project
+// Copyright (c) 2017-2019, The Monero Project
 //
 // All rights reserved.
 //
diff --git a/src/device_trezor/trezor/messages_map.cpp b/src/device_trezor/trezor/messages_map.cpp
index b0d1aa254..6956b369a 100644
--- a/src/device_trezor/trezor/messages_map.cpp
+++ b/src/device_trezor/trezor/messages_map.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018, The Monero Project
+// Copyright (c) 2017-2019, The Monero Project
 //
 // All rights reserved.
 //
@@ -33,6 +33,10 @@
 #include "messages/messages-management.pb.h"
 #include "messages/messages-monero.pb.h"
 
+#ifdef WITH_TREZOR_DEBUGGING
+#include "messages/messages-debug.pb.h"
+#endif
+
 using namespace std;
 using namespace hw::trezor;
 
@@ -45,6 +49,9 @@ namespace trezor
       "hw.trezor.messages.",
       "hw.trezor.messages.common.",
       "hw.trezor.messages.management.",
+#ifdef WITH_TREZOR_DEBUGGING
+      "hw.trezor.messages.debug.",
+#endif
       "hw.trezor.messages.monero."
   };
 
@@ -68,6 +75,10 @@ namespace trezor
     hw::trezor::messages::management::Cancel::default_instance();
     hw::trezor::messages::monero::MoneroGetAddress::default_instance();
 
+#ifdef WITH_TREZOR_DEBUGGING
+    hw::trezor::messages::debug::DebugLinkDecision::default_instance();
+#endif
+
     google::protobuf::Descriptor const * desc = nullptr;
     for(const string &text : PACKAGES){
       desc = google::protobuf::DescriptorPool::generated_pool()
diff --git a/src/device_trezor/trezor/messages_map.hpp b/src/device_trezor/trezor/messages_map.hpp
index f61338f09..28fe9f4c2 100644
--- a/src/device_trezor/trezor/messages_map.hpp
+++ b/src/device_trezor/trezor/messages_map.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018, The Monero Project
+// Copyright (c) 2017-2019, The Monero Project
 //
 // All rights reserved.
 //
@@ -62,14 +62,14 @@ namespace trezor {
     static messages::MessageType get_message_wire_number(const google::protobuf::Message & msg);
     static messages::MessageType get_message_wire_number(const std::string & msg_name);
 
-    template<class t_message>
+    template<class t_message=google::protobuf::Message>
     static messages::MessageType get_message_wire_number() {
       BOOST_STATIC_ASSERT(boost::is_base_of<google::protobuf::Message, t_message>::value);
       return get_message_wire_number(t_message::default_instance().GetDescriptor()->name());
     }
   };
 
-  template<class t_message>
+  template<class t_message=google::protobuf::Message>
   std::shared_ptr<t_message> message_ptr_retype(std::shared_ptr<google::protobuf::Message> & in){
     BOOST_STATIC_ASSERT(boost::is_base_of<google::protobuf::Message, t_message>::value);
     if (!in){
@@ -79,7 +79,7 @@ namespace trezor {
     return std::dynamic_pointer_cast<t_message>(in);
   }
 
-  template<class t_message>
+  template<class t_message=google::protobuf::Message>
   std::shared_ptr<t_message> message_ptr_retype_static(std::shared_ptr<google::protobuf::Message> & in){
     BOOST_STATIC_ASSERT(boost::is_base_of<google::protobuf::Message, t_message>::value);
     if (!in){
diff --git a/src/device_trezor/trezor/protocol.cpp b/src/device_trezor/trezor/protocol.cpp
index 13506a67f..db2444df6 100644
--- a/src/device_trezor/trezor/protocol.cpp
+++ b/src/device_trezor/trezor/protocol.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018, The Monero Project
+// Copyright (c) 2017-2019, The Monero Project
 //
 // All rights reserved.
 //
@@ -33,6 +33,8 @@
 #include <utility>
 #include <boost/endian/conversion.hpp>
 #include <common/apply_permutation.h>
+#include <common/json_util.h>
+#include <crypto/hmac-keccak.h>
 #include <ringct/rctSigs.h>
 #include <ringct/bulletproofs.h>
 #include "cryptonote_config.h"
@@ -40,6 +42,37 @@
 #include <sodium/crypto_verify_32.h>
 #include <sodium/crypto_aead_chacha20poly1305.h>
 
+#define GET_FIELD_STRING(name, type, jtype) field_##name = std::string(json[#name].GetString(), json[#name].GetStringLength())
+#define GET_FIELD_OTHER(name, type, jtype) field_##name = static_cast<type>(json[#name].Get##jtype())
+
+#define GET_STRING_FROM_JSON(json, name, type, mandatory, def) \
+  GET_FIELD_FROM_JSON_EX(json, name, type, String, mandatory, def, GET_FIELD_STRING)
+
+#define GET_FIELD_FROM_JSON(json, name, type, jtype, mandatory, def) \
+  GET_FIELD_FROM_JSON_EX(json, name, type, jtype, mandatory, def, GET_FIELD_OTHER)
+
+#define GET_FIELD_FROM_JSON_EX(json, name, type, jtype, mandatory, def, VAL) \
+  type field_##name = static_cast<type>(def);                        \
+  bool field_##name##_found = false;                                 \
+  (void)field_##name##_found;                                        \
+  do if (json.HasMember(#name))                                      \
+  {                                                                  \
+    if (json[#name].Is##jtype())                                     \
+    {                                                                \
+      VAL(name, type, jtype);                                        \
+      field_##name##_found = true;                                   \
+    }                                                                \
+    else                                                             \
+    {                                                                \
+      throw std::invalid_argument("Field " #name " found in JSON, but not " #jtype); \
+    }                                                                \
+  }                                                                  \
+  else if (mandatory)                                                \
+  {                                                                  \
+    throw std::invalid_argument("Field " #name " not found in JSON");\
+  } while(0)
+
+
 namespace hw{
 namespace trezor{
 namespace protocol{
@@ -84,19 +117,22 @@ namespace protocol{
 namespace crypto {
 namespace chacha {
 
-  void decrypt(const void* ciphertext, size_t length, const uint8_t* key, const uint8_t* iv, char* plaintext){
-    if (length < 16){
-      throw std::invalid_argument("Ciphertext length too small");
-    }
+  void decrypt(const void* ciphertext, size_t length, const uint8_t* key, const uint8_t* iv, char* plaintext, size_t *plaintext_len){
+    CHECK_AND_ASSERT_THROW_MES(length >= TAG_SIZE, "Ciphertext length too small");
+    CHECK_AND_ASSERT_THROW_MES(!plaintext_len || *plaintext_len >= (length - TAG_SIZE), "Plaintext length too small");
 
-    unsigned long long int cip_len = length;
+    unsigned long long int res_len = plaintext_len ? *plaintext_len : length;
     auto r = crypto_aead_chacha20poly1305_ietf_decrypt(
-        reinterpret_cast<unsigned char *>(plaintext), &cip_len, nullptr,
+        reinterpret_cast<unsigned char *>(plaintext), &res_len, nullptr,
         static_cast<const unsigned char *>(ciphertext), length, nullptr, 0, iv, key);
 
     if (r != 0){
       throw exc::Poly1305TagInvalid();
     }
+
+    if (plaintext_len){
+      *plaintext_len = (size_t) res_len;
+    }
   }
 
 }
@@ -185,6 +221,49 @@ namespace ki {
     }
   }
 
+  void live_refresh_ack(const ::crypto::secret_key & view_key_priv,
+                        const ::crypto::public_key& out_key,
+                        const std::shared_ptr<messages::monero::MoneroLiveRefreshStepAck> & ack,
+                        ::cryptonote::keypair& in_ephemeral,
+                        ::crypto::key_image& ki)
+  {
+    std::string str_out_key(out_key.data, sizeof(out_key.data));
+    auto enc_key = protocol::tx::compute_enc_key(view_key_priv, str_out_key, ack->salt());
+
+    const size_t len_ciphertext = ack->key_image().size();  // IV || keys
+    CHECK_AND_ASSERT_THROW_MES(len_ciphertext > crypto::chacha::IV_SIZE + crypto::chacha::TAG_SIZE, "Invalid size");
+
+    size_t ki_len = len_ciphertext - crypto::chacha::IV_SIZE - crypto::chacha::TAG_SIZE;
+    std::unique_ptr<uint8_t[]> plaintext(new uint8_t[ki_len]);
+    uint8_t * buff = plaintext.get();
+
+    protocol::crypto::chacha::decrypt(
+        ack->key_image().data() + crypto::chacha::IV_SIZE,
+        len_ciphertext - crypto::chacha::IV_SIZE,
+        reinterpret_cast<const uint8_t *>(enc_key.data),
+        reinterpret_cast<const uint8_t *>(ack->key_image().data()),
+        reinterpret_cast<char *>(buff), &ki_len);
+
+    CHECK_AND_ASSERT_THROW_MES(ki_len == 3*32, "Invalid size");
+    ::crypto::signature sig{};
+    memcpy(ki.data, buff, 32);
+    memcpy(sig.c.data, buff + 32, 32);
+    memcpy(sig.r.data, buff + 64, 32);
+    in_ephemeral.pub = out_key;
+    in_ephemeral.sec = ::crypto::null_skey;
+
+    // Verification
+    std::vector<const ::crypto::public_key*> pkeys;
+    pkeys.push_back(&out_key);
+
+    CHECK_AND_ASSERT_THROW_MES(rct::scalarmultKey(rct::ki2rct(ki), rct::curveOrder()) == rct::identity(),
+                               "Key image out of validity domain: key image " << epee::string_tools::pod_to_hex(ki));
+
+    CHECK_AND_ASSERT_THROW_MES(::crypto::check_ring_signature((const ::crypto::hash&)ki, ki, pkeys, &sig),
+                               "Signature failed for key image " << epee::string_tools::pod_to_hex(ki)
+                                                                 << ", signature " + epee::string_tools::pod_to_hex(sig)
+                                                                 << ", pubkey " + epee::string_tools::pod_to_hex(*pkeys[0]));
+  }
 }
 
 // Cold transaction signing
@@ -198,6 +277,8 @@ namespace tx {
   void translate_dst_entry(MoneroTransactionDestinationEntry * dst, const cryptonote::tx_destination_entry * src){
     dst->set_amount(src->amount);
     dst->set_is_subaddress(src->is_subaddress);
+    dst->set_is_integrated(src->is_integrated);
+    dst->set_original(src->original);
     translate_address(dst->mutable_addr(), &(src->addr));
   }
 
@@ -267,9 +348,29 @@ namespace tx {
     return std::string(buff, offset);
   }
 
+  ::crypto::secret_key compute_enc_key(const ::crypto::secret_key & private_view_key, const std::string & aux, const std::string & salt)
+  {
+    uint8_t hash[32];
+    KECCAK_CTX ctx;
+    ::crypto::secret_key res;
+
+    keccak_init(&ctx);
+    keccak_update(&ctx, (const uint8_t *) private_view_key.data, sizeof(private_view_key.data));
+    if (!aux.empty()){
+      keccak_update(&ctx, (const uint8_t *) aux.data(), aux.size());
+    }
+    keccak_finish(&ctx, hash);
+    keccak(hash, sizeof(hash), hash, sizeof(hash));
+
+    hmac_keccak_hash(hash, (const uint8_t *) salt.data(), salt.size(), hash, sizeof(hash));
+    memcpy(res.data, hash, sizeof(hash));
+    memwipe(hash, sizeof(hash));
+    return res;
+  }
+
   TData::TData() {
-    in_memory = false;
     rsig_type = 0;
+    bp_version = 0;
     cur_input_idx = 0;
     cur_output_idx = 0;
     cur_batch_idx = 0;
@@ -283,6 +384,7 @@ namespace tx {
     m_tx_idx = tx_idx;
     m_ct.tx_data = cur_tx();
     m_multisig = false;
+    m_client_version = 1;
   }
 
   void Signer::extract_payment_id(){
@@ -392,8 +494,10 @@ namespace tx {
 
     m_ct.tx.version = 2;
     m_ct.tx.unlock_time = tx.unlock_time;
+    m_client_version = (m_aux_data->client_version ? m_aux_data->client_version.get() : 1);
 
     tsx_data.set_version(1);
+    tsx_data.set_client_version(client_version());
     tsx_data.set_unlock_time(tx.unlock_time);
     tsx_data.set_num_inputs(static_cast<google::protobuf::uint32>(tx.sources.size()));
     tsx_data.set_mixin(static_cast<google::protobuf::uint32>(tx.sources[0].outputs.size() - 1));
@@ -404,6 +508,10 @@ namespace tx {
     auto rsig_data = tsx_data.mutable_rsig_data();
     m_ct.rsig_type = get_rsig_type(tx.use_bulletproofs, tx.splitted_dsts.size());
     rsig_data->set_rsig_type(m_ct.rsig_type);
+    if (tx.use_bulletproofs){
+      m_ct.bp_version = (m_aux_data->bp_version ? m_aux_data->bp_version.get() : 1);
+      rsig_data->set_bp_version((uint32_t) m_ct.bp_version);
+    }
 
     generate_rsig_batch_sizes(m_ct.grouping_vct, m_ct.rsig_type, tx.splitted_dsts.size());
     assign_to_repeatable(rsig_data->mutable_grouping(), m_ct.grouping_vct.begin(), m_ct.grouping_vct.end());
@@ -437,7 +545,6 @@ namespace tx {
   }
 
   void Signer::step_init_ack(std::shared_ptr<const messages::monero::MoneroTransactionInitAck> ack){
-    m_ct.in_memory = false;
     if (ack->has_rsig_data()){
       m_ct.rsig_param = std::make_shared<MoneroRsigData>(ack->rsig_data());
     }
@@ -505,10 +612,6 @@ namespace tx {
   std::shared_ptr<messages::monero::MoneroTransactionInputsPermutationRequest> Signer::step_permutation(){
     sort_ki();
 
-    if (in_memory()){
-      return nullptr;
-    }
-
     auto res = std::make_shared<messages::monero::MoneroTransactionInputsPermutationRequest>();
     assign_to_repeatable(res->mutable_perm(), m_ct.source_permutation.begin(), m_ct.source_permutation.end());
 
@@ -516,15 +619,10 @@ namespace tx {
   }
 
   void Signer::step_permutation_ack(std::shared_ptr<const messages::monero::MoneroTransactionInputsPermutationAck> ack){
-    if (in_memory()){
-      return;
-    }
+
   }
 
   std::shared_ptr<messages::monero::MoneroTransactionInputViniRequest> Signer::step_set_vini_input(size_t idx){
-    if (in_memory()){
-      return nullptr;
-    }
     CHECK_AND_ASSERT_THROW_MES(idx < m_ct.tx_data.sources.size(), "Invalid transaction index");
     CHECK_AND_ASSERT_THROW_MES(idx < m_ct.tx.vin.size(), "Invalid transaction index");
     CHECK_AND_ASSERT_THROW_MES(idx < m_ct.tx_in_hmacs.size(), "Invalid transaction index");
@@ -536,7 +634,8 @@ namespace tx {
     translate_src_entry(res->mutable_src_entr(), &(tx.sources[idx]));
     res->set_vini(cryptonote::t_serializable_object_to_blob(vini));
     res->set_vini_hmac(m_ct.tx_in_hmacs[idx]);
-    if (!in_memory()) {
+
+    if (client_version() == 0) {
       CHECK_AND_ASSERT_THROW_MES(idx < m_ct.pseudo_outs.size(), "Invalid transaction index");
       CHECK_AND_ASSERT_THROW_MES(idx < m_ct.pseudo_outs_hmac.size(), "Invalid transaction index");
       res->set_pseudo_out(m_ct.pseudo_outs[idx]);
@@ -547,9 +646,7 @@ namespace tx {
   }
 
   void Signer::step_set_vini_input_ack(std::shared_ptr<const messages::monero::MoneroTransactionInputViniAck> ack){
-    if (in_memory()){
-      return;
-    }
+
   }
 
   std::shared_ptr<messages::monero::MoneroTransactionAllInputsSetRequest> Signer::step_all_inputs_set(){
@@ -557,34 +654,37 @@ namespace tx {
   }
 
   void Signer::step_all_inputs_set_ack(std::shared_ptr<const messages::monero::MoneroTransactionAllInputsSetAck> ack){
-    if (is_offloading()){
-      // If offloading, expect rsig configuration.
-      if (!ack->has_rsig_data()){
-        throw exc::ProtocolException("Rsig offloading requires rsig param");
-      }
+    if (client_version() > 0 || !is_offloading()){
+      return;
+    }
 
-      auto & rsig_data = ack->rsig_data();
-      if (!rsig_data.has_mask()){
-        throw exc::ProtocolException("Gamma masks not present in offloaded version");
-      }
+    // If offloading, expect rsig configuration.
+    if (!ack->has_rsig_data()){
+      throw exc::ProtocolException("Rsig offloading requires rsig param");
+    }
 
-      auto & mask = rsig_data.mask();
-      if (mask.size() != 32 * num_outputs()){
-        throw exc::ProtocolException("Invalid number of gamma masks");
-      }
+    auto & rsig_data = ack->rsig_data();
+    if (!rsig_data.has_mask()){
+      throw exc::ProtocolException("Gamma masks not present in offloaded version");
+    }
 
-      m_ct.rsig_gamma.reserve(num_outputs());
-      for(size_t c=0; c < num_outputs(); ++c){
-        rct::key cmask{};
-        memcpy(cmask.bytes, mask.data() + c * 32, 32);
-        m_ct.rsig_gamma.emplace_back(cmask);
-      }
+    auto & mask = rsig_data.mask();
+    if (mask.size() != 32 * num_outputs()){
+      throw exc::ProtocolException("Invalid number of gamma masks");
+    }
+
+    m_ct.rsig_gamma.reserve(num_outputs());
+    for(size_t c=0; c < num_outputs(); ++c){
+      rct::key cmask{};
+      memcpy(cmask.bytes, mask.data() + c * 32, 32);
+      m_ct.rsig_gamma.emplace_back(cmask);
     }
   }
 
   std::shared_ptr<messages::monero::MoneroTransactionSetOutputRequest> Signer::step_set_output(size_t idx){
     CHECK_AND_ASSERT_THROW_MES(idx < m_ct.tx_data.splitted_dsts.size(), "Invalid transaction index");
     CHECK_AND_ASSERT_THROW_MES(idx < m_ct.tx_out_entr_hmacs.size(), "Invalid transaction index");
+    CHECK_AND_ASSERT_THROW_MES(is_req_bulletproof(), "Borromean rsig not supported");
 
     m_ct.cur_output_idx = idx;
     m_ct.cur_output_in_batch_idx += 1;   // assumes sequential call to step_set_output()
@@ -595,48 +695,11 @@ namespace tx {
     res->set_dst_entr_hmac(m_ct.tx_out_entr_hmacs[idx]);
 
     // Range sig offloading to the host
-    if (!is_offloading()) {
-      return res;
-    }
-
-    CHECK_AND_ASSERT_THROW_MES(m_ct.cur_batch_idx < m_ct.grouping_vct.size(), "Invalid batch index");
-    if (m_ct.grouping_vct[m_ct.cur_batch_idx] > m_ct.cur_output_in_batch_idx) {
-      return res;
-    }
-
-    auto rsig_data = res->mutable_rsig_data();
-    auto batch_size = m_ct.grouping_vct[m_ct.cur_batch_idx];
-
-    if (!is_req_bulletproof()){
-      if (batch_size > 1){
-        throw std::invalid_argument("Borromean cannot batch outputs");
-      }
-
-      CHECK_AND_ASSERT_THROW_MES(idx < m_ct.rsig_gamma.size(), "Invalid gamma index");
-      rct::key C{}, mask = m_ct.rsig_gamma[idx];
-      auto genRsig = rct::proveRange(C, mask, cur_dst.amount);  // TODO: rsig with given mask
-      auto serRsig = cn_serialize(genRsig);
-      m_ct.tx_out_rsigs.emplace_back(genRsig);
-      rsig_data->set_rsig(serRsig);
-
-    } else {
-      std::vector<uint64_t> amounts;
-      rct::keyV masks;
-      CHECK_AND_ASSERT_THROW_MES(idx + 1 >= batch_size, "Invalid index for batching");
-
-      for(size_t i = 0; i < batch_size; ++i){
-        const size_t bidx = 1 + idx - batch_size + i;
-        CHECK_AND_ASSERT_THROW_MES(bidx < m_ct.tx_data.splitted_dsts.size(), "Invalid gamma index");
-        CHECK_AND_ASSERT_THROW_MES(bidx < m_ct.rsig_gamma.size(), "Invalid gamma index");
-
-        amounts.push_back(m_ct.tx_data.splitted_dsts[bidx].amount);
-        masks.push_back(m_ct.rsig_gamma[bidx]);
-      }
-
-      auto bp = bulletproof_PROVE(amounts, masks);
-      auto serRsig = cn_serialize(bp);
-      m_ct.tx_out_rsigs.emplace_back(bp);
-      rsig_data->set_rsig(serRsig);
+    // ClientV0 sends offloaded BP with the last message in the batch.
+    // ClientV1 needs additional message after the last message in the batch as BP uses deterministic masks.
+    if (client_version() == 0 && is_offloading() && should_compute_bp_now()) {
+      auto rsig_data = res->mutable_rsig_data();
+      compute_bproof(*rsig_data);
     }
 
     return res;
@@ -644,7 +707,6 @@ namespace tx {
 
   void Signer::step_set_output_ack(std::shared_ptr<const messages::monero::MoneroTransactionSetOutputAck> ack){
     cryptonote::tx_out tx_out;
-    rct::rangeSig range_sig{};
     rct::Bulletproof bproof{};
     rct::ctkey out_pk{};
     rct::ecdhTuple ecdh{};
@@ -658,12 +720,12 @@ namespace tx {
       if (rsig_data.has_rsig() && !rsig_data.rsig().empty()){
         has_rsig = true;
         rsig_buff = rsig_data.rsig();
+      }
 
-      } else if (rsig_data.rsig_parts_size() > 0){
-        has_rsig = true;
-        for (const auto &it : rsig_data.rsig_parts()) {
-          rsig_buff += it;
-        }
+      if (client_version() >= 1 && rsig_data.has_mask()){
+        rct::key cmask{};
+        string_to_key(cmask, rsig_data.mask());
+        m_ct.rsig_gamma.emplace_back(cmask);
       }
     }
 
@@ -675,12 +737,13 @@ namespace tx {
       throw exc::ProtocolException("Cannot deserialize out_pk");
     }
 
-    if (!cn_deserialize(ack->ecdh_info(), ecdh)){
-      throw exc::ProtocolException("Cannot deserialize ecdhtuple");
-    }
-
-    if (has_rsig && !is_req_bulletproof() && !cn_deserialize(rsig_buff, range_sig)){
-      throw exc::ProtocolException("Cannot deserialize rangesig");
+    if (m_ct.bp_version <= 1) {
+      if (!cn_deserialize(ack->ecdh_info(), ecdh)){
+        throw exc::ProtocolException("Cannot deserialize ecdhtuple");
+      }
+    } else {
+      CHECK_AND_ASSERT_THROW_MES(8 == ack->ecdh_info().size(), "Invalid ECDH.amount size");
+      memcpy(ecdh.amount.bytes, ack->ecdh_info().data(), 8);
     }
 
     if (has_rsig && is_req_bulletproof() && !cn_deserialize(rsig_buff, bproof)){
@@ -692,35 +755,77 @@ namespace tx {
     m_ct.tx_out_pk.emplace_back(out_pk);
     m_ct.tx_out_ecdh.emplace_back(ecdh);
 
-    if (!has_rsig){
+    // ClientV0, if no rsig was generated on Trezor, do not continue.
+    // ClientV1+ generates BP after all masks in the current batch are generated
+    if (!has_rsig || (client_version() >= 1 && is_offloading())){
       return;
     }
 
-    if (is_req_bulletproof()){
-      CHECK_AND_ASSERT_THROW_MES(m_ct.cur_batch_idx < m_ct.grouping_vct.size(), "Invalid batch index");
-      auto batch_size = m_ct.grouping_vct[m_ct.cur_batch_idx];
-      for (size_t i = 0; i < batch_size; ++i){
-        const size_t bidx = 1 + m_ct.cur_output_idx - batch_size + i;
-        CHECK_AND_ASSERT_THROW_MES(bidx < m_ct.tx_out_pk.size(), "Invalid out index");
+    process_bproof(bproof);
+    m_ct.cur_batch_idx += 1;
+    m_ct.cur_output_in_batch_idx = 0;
+  }
 
-        rct::key commitment = m_ct.tx_out_pk[bidx].mask;
-        commitment = rct::scalarmultKey(commitment, rct::INV_EIGHT);
-        bproof.V.push_back(commitment);
-      }
+  bool Signer::should_compute_bp_now() const {
+    CHECK_AND_ASSERT_THROW_MES(m_ct.cur_batch_idx < m_ct.grouping_vct.size(), "Invalid batch index");
+    return m_ct.grouping_vct[m_ct.cur_batch_idx] <= m_ct.cur_output_in_batch_idx;
+  }
 
-      m_ct.tx_out_rsigs.emplace_back(bproof);
-      if (!rct::bulletproof_VERIFY(boost::get<rct::Bulletproof>(m_ct.tx_out_rsigs.back()))) {
-        throw exc::ProtocolException("Returned range signature is invalid");
-      }
+  void Signer::compute_bproof(messages::monero::MoneroTransactionRsigData & rsig_data){
+    auto batch_size = m_ct.grouping_vct[m_ct.cur_batch_idx];
+    std::vector<uint64_t> amounts;
+    rct::keyV masks;
+    CHECK_AND_ASSERT_THROW_MES(m_ct.cur_output_idx + 1 >= batch_size, "Invalid index for batching");
 
-    } else {
-      m_ct.tx_out_rsigs.emplace_back(range_sig);
+    for(size_t i = 0; i < batch_size; ++i){
+      const size_t bidx = 1 + m_ct.cur_output_idx - batch_size + i;
+      CHECK_AND_ASSERT_THROW_MES(bidx < m_ct.tx_data.splitted_dsts.size(), "Invalid gamma index");
+      CHECK_AND_ASSERT_THROW_MES(bidx < m_ct.rsig_gamma.size(), "Invalid gamma index");
 
-      if (!rct::verRange(out_pk.mask, boost::get<rct::rangeSig>(m_ct.tx_out_rsigs.back()))) {
-        throw exc::ProtocolException("Returned range signature is invalid");
-      }
+      amounts.push_back(m_ct.tx_data.splitted_dsts[bidx].amount);
+      masks.push_back(m_ct.rsig_gamma[bidx]);
     }
 
+    auto bp = bulletproof_PROVE(amounts, masks);
+    auto serRsig = cn_serialize(bp);
+    m_ct.tx_out_rsigs.emplace_back(bp);
+    rsig_data.set_rsig(serRsig);
+  }
+
+  void Signer::process_bproof(rct::Bulletproof & bproof){
+    CHECK_AND_ASSERT_THROW_MES(m_ct.cur_batch_idx < m_ct.grouping_vct.size(), "Invalid batch index");
+    auto batch_size = m_ct.grouping_vct[m_ct.cur_batch_idx];
+    for (size_t i = 0; i < batch_size; ++i){
+      const size_t bidx = 1 + m_ct.cur_output_idx - batch_size + i;
+      CHECK_AND_ASSERT_THROW_MES(bidx < m_ct.tx_out_pk.size(), "Invalid out index");
+
+      rct::key commitment = m_ct.tx_out_pk[bidx].mask;
+      commitment = rct::scalarmultKey(commitment, rct::INV_EIGHT);
+      bproof.V.push_back(commitment);
+    }
+
+    m_ct.tx_out_rsigs.emplace_back(bproof);
+    if (!rct::bulletproof_VERIFY(boost::get<rct::Bulletproof>(m_ct.tx_out_rsigs.back()))) {
+      throw exc::ProtocolException("Returned range signature is invalid");
+    }
+  }
+
+  std::shared_ptr<messages::monero::MoneroTransactionSetOutputRequest> Signer::step_rsig(size_t idx){
+    if (client_version() == 0 || !is_offloading() || !should_compute_bp_now()){
+      return nullptr;
+    }
+
+    auto res = std::make_shared<messages::monero::MoneroTransactionSetOutputRequest>();
+    auto & cur_dst = m_ct.tx_data.splitted_dsts[idx];
+    translate_dst_entry(res->mutable_dst_entr(), &cur_dst);
+    res->set_dst_entr_hmac(m_ct.tx_out_entr_hmacs[idx]);
+
+    compute_bproof(*(res->mutable_rsig_data()));
+    res->set_is_offloaded_bp(true);
+    return res;
+  }
+
+  void Signer::step_set_rsig_ack(std::shared_ptr<const messages::monero::MoneroTransactionSetOutputAck> ack){
     m_ct.cur_batch_idx += 1;
     m_ct.cur_output_in_batch_idx = 0;
   }
@@ -814,12 +919,11 @@ namespace tx {
     res->set_vini_hmac(m_ct.tx_in_hmacs[idx]);
     res->set_pseudo_out_alpha(m_ct.alphas[idx]);
     res->set_spend_key(m_ct.spend_encs[idx]);
-    if (!in_memory()){
-      CHECK_AND_ASSERT_THROW_MES(idx < m_ct.pseudo_outs.size(), "Invalid transaction index");
-      CHECK_AND_ASSERT_THROW_MES(idx < m_ct.pseudo_outs_hmac.size(), "Invalid transaction index");
-      res->set_pseudo_out(m_ct.pseudo_outs[idx]);
-      res->set_pseudo_out_hmac(m_ct.pseudo_outs_hmac[idx]);
-    }
+
+    CHECK_AND_ASSERT_THROW_MES(idx < m_ct.pseudo_outs.size(), "Invalid transaction index");
+    CHECK_AND_ASSERT_THROW_MES(idx < m_ct.pseudo_outs_hmac.size(), "Invalid transaction index");
+    res->set_pseudo_out(m_ct.pseudo_outs[idx]);
+    res->set_pseudo_out_hmac(m_ct.pseudo_outs_hmac[idx]);
     return res;
   }
 
@@ -829,6 +933,19 @@ namespace tx {
       throw exc::ProtocolException("Cannot deserialize mg[i]");
     }
 
+    // Sync updated pseudo_outputs, client_version>=1, HF10+
+    if (client_version() >= 1 && ack->has_pseudo_out()){
+      CHECK_AND_ASSERT_THROW_MES(m_ct.cur_input_idx < m_ct.pseudo_outs.size(), "Invalid pseudo-out index");
+      m_ct.pseudo_outs[m_ct.cur_input_idx] = ack->pseudo_out();
+      if (is_bulletproof()){
+        CHECK_AND_ASSERT_THROW_MES(m_ct.cur_input_idx < m_ct.rv->p.pseudoOuts.size(), "Invalid pseudo-out index");
+        string_to_key(m_ct.rv->p.pseudoOuts[m_ct.cur_input_idx], ack->pseudo_out());
+      } else {
+        CHECK_AND_ASSERT_THROW_MES(m_ct.cur_input_idx < m_ct.rv->pseudoOuts.size(), "Invalid pseudo-out index");
+        string_to_key(m_ct.rv->pseudoOuts[m_ct.cur_input_idx], ack->pseudo_out());
+      }
+    }
+
     m_ct.rv->p.MGs.push_back(mg);
   }
 
@@ -841,14 +958,14 @@ namespace tx {
     if (m_multisig){
       auto & cout_key = ack->cout_key();
       for(auto & cur : m_ct.couts){
-        if (cur.size() != 12 + 32){
+        if (cur.size() != crypto::chacha::IV_SIZE + 32){
           throw std::invalid_argument("Encrypted cout has invalid length");
         }
 
         char buff[32];
         auto data = cur.data();
 
-        crypto::chacha::decrypt(data + 12, 32, reinterpret_cast<const uint8_t *>(cout_key.data()), reinterpret_cast<const uint8_t *>(data), buff);
+        crypto::chacha::decrypt(data + crypto::chacha::IV_SIZE, 32, reinterpret_cast<const uint8_t *>(cout_key.data()), reinterpret_cast<const uint8_t *>(data), buff);
         m_ct.couts_dec.emplace_back(buff, 32);
       }
     }
@@ -887,6 +1004,82 @@ namespace tx {
     return sb.GetString();
   }
 
+  void load_tx_key_data(hw::device_cold::tx_key_data_t & res, const std::string & data)
+  {
+    rapidjson::Document json;
+
+    // The contents should be JSON if the wallet follows the new format.
+    if (json.Parse(data.c_str()).HasParseError())
+    {
+      throw std::invalid_argument("Data parsing error");
+    }
+    else if(!json.IsObject())
+    {
+      throw std::invalid_argument("Data parsing error - not an object");
+    }
+
+    GET_FIELD_FROM_JSON(json, version, int, Int, true, -1);
+    GET_STRING_FROM_JSON(json, salt1, std::string, true, std::string());
+    GET_STRING_FROM_JSON(json, salt2, std::string, true, std::string());
+    GET_STRING_FROM_JSON(json, enc_keys, std::string, true, std::string());
+    GET_STRING_FROM_JSON(json, tx_prefix_hash, std::string, false, std::string());
+
+    if (field_version != 1)
+    {
+      throw std::invalid_argument("Unknown version");
+    }
+
+    res.salt1 = field_salt1;
+    res.salt2 = field_salt2;
+    res.tx_enc_keys = field_enc_keys;
+    res.tx_prefix_hash = field_tx_prefix_hash;
+  }
+
+  std::shared_ptr<messages::monero::MoneroGetTxKeyRequest> get_tx_key(
+      const hw::device_cold::tx_key_data_t & tx_data)
+  {
+    auto req = std::make_shared<messages::monero::MoneroGetTxKeyRequest>();
+    req->set_salt1(tx_data.salt1);
+    req->set_salt2(tx_data.salt2);
+    req->set_tx_enc_keys(tx_data.tx_enc_keys);
+    req->set_tx_prefix_hash(tx_data.tx_prefix_hash);
+    req->set_reason(0);
+
+    return req;
+  }
+
+  void get_tx_key_ack(
+      std::vector<::crypto::secret_key> & tx_keys,
+      const std::string & tx_prefix_hash,
+      const ::crypto::secret_key & view_key_priv,
+      std::shared_ptr<const messages::monero::MoneroGetTxKeyAck> ack
+  )
+  {
+    auto enc_key = protocol::tx::compute_enc_key(view_key_priv, tx_prefix_hash, ack->salt());
+    auto & encrypted_keys = ack->has_tx_derivations() ? ack->tx_derivations() : ack->tx_keys();
+
+    const size_t len_ciphertext = encrypted_keys.size();  // IV || keys || TAG
+    CHECK_AND_ASSERT_THROW_MES(len_ciphertext > crypto::chacha::IV_SIZE + crypto::chacha::TAG_SIZE, "Invalid size");
+
+    size_t keys_len = len_ciphertext - crypto::chacha::IV_SIZE - crypto::chacha::TAG_SIZE;
+    std::unique_ptr<uint8_t[]> plaintext(new uint8_t[keys_len]);
+
+    protocol::crypto::chacha::decrypt(
+        encrypted_keys.data() + crypto::chacha::IV_SIZE,
+        len_ciphertext - crypto::chacha::IV_SIZE,
+        reinterpret_cast<const uint8_t *>(enc_key.data),
+        reinterpret_cast<const uint8_t *>(encrypted_keys.data()),
+        reinterpret_cast<char *>(plaintext.get()), &keys_len);
+
+    CHECK_AND_ASSERT_THROW_MES(keys_len % 32 == 0, "Invalid size");
+    tx_keys.resize(keys_len / 32);
+
+    for(unsigned i = 0; i < keys_len / 32; ++i)
+    {
+      memcpy(tx_keys[i].data, plaintext.get() + 32 * i, 32);
+    }
+    memwipe(plaintext.get(), keys_len);
+  }
 
 }
 }
diff --git a/src/device_trezor/trezor/protocol.hpp b/src/device_trezor/trezor/protocol.hpp
index ce0361640..98ca52565 100644
--- a/src/device_trezor/trezor/protocol.hpp
+++ b/src/device_trezor/trezor/protocol.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018, The Monero Project
+// Copyright (c) 2017-2019, The Monero Project
 //
 // All rights reserved.
 //
@@ -92,11 +92,14 @@ namespace protocol{
 // Crypto / encryption
 namespace crypto {
 namespace chacha {
+  // Constants as defined in RFC 7539.
+  const unsigned IV_SIZE = 12;
+  const unsigned TAG_SIZE = 16;  // crypto_aead_chacha20poly1305_IETF_ABYTES;
 
   /**
    * Chacha20Poly1305 decryption with tag verification. RFC 7539.
    */
-  void decrypt(const void* ciphertext, size_t length, const uint8_t* key, const uint8_t* iv, char* plaintext);
+  void decrypt(const void* ciphertext, size_t length, const uint8_t* key, const uint8_t* iv, char* plaintext, size_t *plaintext_len=nullptr);
 
 }
 }
@@ -129,6 +132,14 @@ namespace ki {
                            const std::vector<tools::wallet2::transfer_details> & transfers,
                            std::shared_ptr<messages::monero::MoneroKeyImageExportInitRequest> & req);
 
+  /**
+   * Processes Live refresh step response, parses KI, checks the signature
+   */
+  void live_refresh_ack(const ::crypto::secret_key & view_key_priv,
+                        const ::crypto::public_key& out_key,
+                        const std::shared_ptr<messages::monero::MoneroLiveRefreshStepAck> & ack,
+                        ::cryptonote::keypair& in_ephemeral,
+                        ::crypto::key_image& ki);
 }
 
 // Cold transaction signing
@@ -153,6 +164,7 @@ namespace tx {
   std::string hash_addr(const MoneroAccountPublicAddress * addr, boost::optional<uint64_t> amount = boost::none, boost::optional<bool> is_subaddr = boost::none);
   std::string hash_addr(const std::string & spend_key, const std::string & view_key, boost::optional<uint64_t> amount = boost::none, boost::optional<bool> is_subaddr = boost::none);
   std::string hash_addr(const ::crypto::public_key * spend_key, const ::crypto::public_key * view_key, boost::optional<uint64_t> amount = boost::none, boost::optional<bool> is_subaddr = boost::none);
+  ::crypto::secret_key compute_enc_key(const ::crypto::secret_key & private_view_key, const std::string & aux, const std::string & salt);
 
   typedef boost::variant<rct::rangeSig, rct::Bulletproof> rsig_v;
 
@@ -164,8 +176,8 @@ namespace tx {
     TsxData tsx_data;
     tx_construction_data tx_data;
     cryptonote::transaction tx;
-    bool in_memory;
     unsigned rsig_type;
+    int bp_version;
     std::vector<uint64_t> grouping_vct;
     std::shared_ptr<MoneroRsigData> rsig_param;
     size_t cur_input_idx;
@@ -206,6 +218,7 @@ namespace tx {
     const unsigned_tx_set * m_unsigned_tx;
     hw::tx_aux_data * m_aux_data;
 
+    unsigned m_client_version;
     bool m_multisig;
 
     const tx_construction_data & cur_tx(){
@@ -215,6 +228,9 @@ namespace tx {
 
     void extract_payment_id();
     void compute_integrated_indices(TsxData * tsx_data);
+    bool should_compute_bp_now() const;
+    void compute_bproof(messages::monero::MoneroTransactionRsigData & rsig_data);
+    void process_bproof(rct::Bulletproof & bproof);
 
   public:
     Signer(wallet_shim * wallet2, const unsigned_tx_set * unsigned_tx, size_t tx_idx = 0, hw::tx_aux_data * aux_data = nullptr);
@@ -238,6 +254,9 @@ namespace tx {
     std::shared_ptr<messages::monero::MoneroTransactionSetOutputRequest> step_set_output(size_t idx);
     void step_set_output_ack(std::shared_ptr<const messages::monero::MoneroTransactionSetOutputAck> ack);
 
+    std::shared_ptr<messages::monero::MoneroTransactionSetOutputRequest> step_rsig(size_t idx);
+    void step_set_rsig_ack(std::shared_ptr<const messages::monero::MoneroTransactionSetOutputAck> ack);
+
     std::shared_ptr<messages::monero::MoneroTransactionAllOutSetRequest> step_all_outs_set();
     void step_all_outs_set_ack(std::shared_ptr<const messages::monero::MoneroTransactionAllOutSetAck> ack, hw::device &hwdev);
 
@@ -249,8 +268,8 @@ namespace tx {
 
     std::string store_tx_aux_info();
 
-    bool in_memory() const {
-      return m_ct.in_memory;
+    unsigned client_version() const {
+      return m_client_version;
     }
 
     bool is_simple() const {
@@ -290,6 +309,18 @@ namespace tx {
     }
   };
 
+  // TX Key decryption
+  void load_tx_key_data(hw::device_cold::tx_key_data_t & res, const std::string & data);
+
+  std::shared_ptr<messages::monero::MoneroGetTxKeyRequest> get_tx_key(
+      const hw::device_cold::tx_key_data_t & tx_data);
+
+  void get_tx_key_ack(
+      std::vector<::crypto::secret_key> & tx_keys,
+      const std::string & tx_prefix_hash,
+      const ::crypto::secret_key & view_key_priv,
+      std::shared_ptr<const messages::monero::MoneroGetTxKeyAck> ack
+  );
 }
 
 }
diff --git a/src/device_trezor/trezor/tools/build_protob.py b/src/device_trezor/trezor/tools/build_protob.py
index 2611f3296..eb32f6b4d 100644
--- a/src/device_trezor/trezor/tools/build_protob.py
+++ b/src/device_trezor/trezor/tools/build_protob.py
@@ -2,6 +2,12 @@
 import os
 import subprocess
 import sys
+import argparse
+
+
+parser = argparse.ArgumentParser()
+parser.add_argument("-d", "--debug-msg", default=False, action="store_const", const=True, help="Build debug messages")
+args = parser.parse_args()
 
 CWD = os.path.dirname(os.path.realpath(__file__))
 ROOT_DIR = os.path.abspath(os.path.join(CWD, "..", "..", "..", ".."))
@@ -24,6 +30,10 @@ try:
         "messages-management.proto",
         "messages-monero.proto",
     ]
+
+    if args.debug_msg:
+        selected += ["messages-debug.proto"]
+
     proto_srcs = [os.path.join(TREZOR_COMMON, "protob", x) for x in selected]
     exec_args = [
         sys.executable,
diff --git a/src/device_trezor/trezor/transport.cpp b/src/device_trezor/trezor/transport.cpp
index cd66e59e8..991ba3395 100644
--- a/src/device_trezor/trezor/transport.cpp
+++ b/src/device_trezor/trezor/transport.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018, The Monero Project
+// Copyright (c) 2017-2019, The Monero Project
 //
 // All rights reserved.
 //
@@ -84,6 +84,17 @@ namespace trezor{
     return std::string(in.GetString());
   }
 
+  uint64_t pack_version(uint32_t major, uint32_t minor, uint32_t patch)
+  {
+    // packing (major, minor, patch) to 64 B: 16 B | 24 B | 24 B
+    const unsigned bits_1 = 16;
+    const unsigned bits_2 = 24;
+    const uint32_t mask_1 = (1 << bits_1) - 1;
+    const uint32_t mask_2 = (1 << bits_2) - 1;
+    CHECK_AND_ASSERT_THROW_MES(major <= mask_1 && minor <= mask_2 && patch <= mask_2, "Version numbers overflow packing scheme");
+    return patch | (((uint64_t)minor) << bits_2) | (((uint64_t)major) << (bits_1 + bits_2));
+  }
+
   //
   // Helpers
   //
@@ -212,6 +223,40 @@ namespace trezor{
     msg = msg_wrap;
   }
 
+  Transport::Transport(): m_open_counter(0) {
+
+  }
+
+  bool Transport::pre_open(){
+    if (m_open_counter > 0){
+      MTRACE("Already opened, count: " << m_open_counter);
+      m_open_counter += 1;
+      return false;
+
+    } else if (m_open_counter < 0){
+      MTRACE("Negative open value: " << m_open_counter);
+
+    }
+
+    // Caller should set m_open_counter to 1 after open
+    m_open_counter = 0;
+    return true;
+  }
+
+  bool Transport::pre_close(){
+    m_open_counter -= 1;
+
+    if (m_open_counter < 0){
+      MDEBUG("Already closed. Counter " << m_open_counter);
+
+    } else if (m_open_counter == 0) {
+      return true;
+
+    }
+
+    return false;
+  }
+
   //
   // Bridge transport
   //
@@ -246,6 +291,10 @@ namespace trezor{
   }
 
   void BridgeTransport::open() {
+    if (!pre_open()){
+      return;
+    }
+
     if (!m_device_path){
       throw exc::CommunicationException("Coud not open, empty device path");
     }
@@ -259,9 +308,15 @@ namespace trezor{
     }
 
     m_session = boost::make_optional(json_get_string(bridge_res["session"]));
+    m_open_counter = 1;
   }
 
   void BridgeTransport::close() {
+    if (!pre_close()){
+      return;
+    }
+
+    MTRACE("Closing Trezor:BridgeTransport");
     if (!m_device_path || !m_session){
       throw exc::CommunicationException("Device not open");
     }
@@ -423,6 +478,10 @@ namespace trezor{
   }
 
   void UdpTransport::open() {
+    if (!pre_open()){
+      return;
+    }
+
     udp::resolver resolver(m_io_service);
     udp::resolver::query query(udp::v4(), m_device_host, std::to_string(m_device_port));
     m_endpoint = *resolver.resolve(query);
@@ -434,10 +493,16 @@ namespace trezor{
     check_deadline();
 
     m_proto->session_begin(*this);
+    m_open_counter = 1;
   }
 
   void UdpTransport::close() {
-    if (!m_socket){
+    if (!pre_close()){
+      return;
+    }
+
+    MTRACE("Closing Trezor:UdpTransport");
+    if (!m_socket) {
       throw exc::CommunicationException("Socket is already closed");
     }
 
@@ -446,6 +511,19 @@ namespace trezor{
     m_socket = nullptr;
   }
 
+  std::shared_ptr<Transport> UdpTransport::find_debug() {
+#ifdef WITH_TREZOR_DEBUGGING
+    std::shared_ptr<UdpTransport> t = std::make_shared<UdpTransport>();
+    t->m_proto = std::make_shared<ProtocolV1>();
+    t->m_device_host = m_device_host;
+    t->m_device_port = m_device_port + 1;
+    return t;
+#else
+    MINFO("Debug link is disabled in production");
+    return nullptr;
+#endif
+  }
+
   void UdpTransport::write_chunk(const void * buff, size_t size){
     require_socket();
 
@@ -660,8 +738,7 @@ namespace trezor{
   WebUsbTransport::WebUsbTransport(
       boost::optional<libusb_device_descriptor*> descriptor,
       boost::optional<std::shared_ptr<Protocol>> proto
-  ): m_conn_count(0),
-     m_usb_session(nullptr), m_usb_device(nullptr), m_usb_device_handle(nullptr),
+  ): m_usb_session(nullptr), m_usb_device(nullptr), m_usb_device_handle(nullptr),
      m_bus_id(-1), m_device_addr(-1)
   {
     if (descriptor){
@@ -672,7 +749,7 @@ namespace trezor{
 
     m_proto = proto ? proto.get() : std::make_shared<ProtocolV1>();
 
-#ifdef WITH_TREZOR_DEBUG
+#ifdef WITH_TREZOR_DEBUGGING
     m_debug_mode = false;
 #endif
   }
@@ -757,12 +834,10 @@ namespace trezor{
   };
 
   void WebUsbTransport::open() {
-    const int interface = get_interface();
-    if (m_conn_count > 0){
-      MTRACE("Already opened, count: " << m_conn_count);
-      m_conn_count += 1;
+    if (!pre_open()){
       return;
     }
+    const int interface = get_interface();
 
 #define TREZOR_DESTROY_SESSION() do { libusb_exit(m_usb_session); m_usb_session = nullptr; } while(0)
 
@@ -840,45 +915,55 @@ namespace trezor{
       throw exc::DeviceAcquireException("Unable to claim libusb device");
     }
 
-    m_conn_count = 1;
+    m_open_counter = 1;
     m_proto->session_begin(*this);
     
 #undef TREZOR_DESTROY_SESSION
   };
 
   void WebUsbTransport::close() {
-    m_conn_count -= 1;
-
-    if (m_conn_count < 0){
-      MERROR("Close counter is negative: " << m_conn_count);
-
-    } else if (m_conn_count == 0){
-      MTRACE("Closing webusb device");
+    if (!pre_close()){
+      return;
+    }
 
-      m_proto->session_end(*this);
+    MTRACE("Closing Trezor:WebUsbTransport");
+    m_proto->session_end(*this);
 
-      int r = libusb_release_interface(m_usb_device_handle, get_interface());
-      if (r != 0){
-        MERROR("Could not release libusb interface: " << r);
-      }
+    int r = libusb_release_interface(m_usb_device_handle, get_interface());
+    if (r != 0){
+      MERROR("Could not release libusb interface: " << r);
+    }
 
-      m_usb_device = nullptr;
-      if (m_usb_device_handle) {
-        libusb_close(m_usb_device_handle);
-        m_usb_device_handle = nullptr;
-      }
+    m_usb_device = nullptr;
+    if (m_usb_device_handle) {
+      libusb_close(m_usb_device_handle);
+      m_usb_device_handle = nullptr;
+    }
 
-      if (m_usb_session) {
-        libusb_exit(m_usb_session);
-        m_usb_session = nullptr;
-      }
+    if (m_usb_session) {
+      libusb_exit(m_usb_session);
+      m_usb_session = nullptr;
     }
   };
 
+  std::shared_ptr<Transport> WebUsbTransport::find_debug() {
+#ifdef WITH_TREZOR_DEBUGGING
+    require_device();
+    auto t = std::make_shared<WebUsbTransport>(boost::make_optional(m_usb_device_desc.get()));
+    t->m_bus_id = m_bus_id;
+    t->m_device_addr = m_device_addr;
+    t->m_port_numbers = m_port_numbers;
+    t->m_debug_mode = true;
+    return t;
+#else
+      MINFO("Debug link is disabled in production");
+      return nullptr;
+#endif
+    }
 
   int WebUsbTransport::get_interface() const{
     const int INTERFACE_NORMAL = 0;
-#ifdef WITH_TREZOR_DEBUG
+#ifdef WITH_TREZOR_DEBUGGING
     const int INTERFACE_DEBUG = 1;
     return m_debug_mode ? INTERFACE_DEBUG : INTERFACE_NORMAL;
 #else
@@ -888,7 +973,7 @@ namespace trezor{
 
   unsigned char WebUsbTransport::get_endpoint() const{
     const unsigned char ENDPOINT_NORMAL = 1;
-#ifdef WITH_TREZOR_DEBUG
+#ifdef WITH_TREZOR_DEBUGGING
     const unsigned char ENDPOINT_DEBUG = 2;
     return m_debug_mode ? ENDPOINT_DEBUG : ENDPOINT_NORMAL;
 #else
@@ -1047,4 +1132,3 @@ namespace trezor{
 }
 }
 
-
diff --git a/src/device_trezor/trezor/transport.hpp b/src/device_trezor/trezor/transport.hpp
index 1cf0daa85..2945b3184 100644
--- a/src/device_trezor/trezor/transport.hpp
+++ b/src/device_trezor/trezor/transport.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018, The Monero Project
+// Copyright (c) 2017-2019, The Monero Project
 //
 // All rights reserved.
 //
@@ -62,6 +62,8 @@ namespace trezor {
 
   const std::string DEFAULT_BRIDGE = "127.0.0.1:21325";
 
+  uint64_t pack_version(uint32_t major, uint32_t minor=0, uint32_t patch=0);
+
   // Base HTTP comm serialization.
   bool t_serialize(const std::string & in, std::string & out);
   bool t_serialize(const json_val & in, std::string & out);
@@ -134,7 +136,7 @@ namespace trezor {
 
   class Transport {
   public:
-    Transport() = default;
+    Transport();
     virtual ~Transport() = default;
 
     virtual bool ping() { return false; };
@@ -144,10 +146,16 @@ namespace trezor {
     virtual void close(){};
     virtual void write(const google::protobuf::Message & req) =0;
     virtual void read(std::shared_ptr<google::protobuf::Message> & msg, messages::MessageType * msg_type=nullptr) =0;
+    virtual std::shared_ptr<Transport> find_debug() { return nullptr; };
 
     virtual void write_chunk(const void * buff, size_t size) { };
     virtual size_t read_chunk(void * buff, size_t size) { return 0; };
     virtual std::ostream& dump(std::ostream& o) const { return o << "Transport<>"; }
+  protected:
+    long m_open_counter;
+
+    virtual bool pre_open();
+    virtual bool pre_close();
   };
 
   // Bridge transport
@@ -212,6 +220,7 @@ namespace trezor {
 
     void open() override;
     void close() override;
+    std::shared_ptr<Transport> find_debug() override;
 
     void write(const google::protobuf::Message &req) override;
     void read(std::shared_ptr<google::protobuf::Message> & msg, messages::MessageType * msg_type=nullptr) override;
@@ -259,6 +268,7 @@ namespace trezor {
 
     void open() override;
     void close() override;
+    std::shared_ptr<Transport> find_debug() override;
 
     void write(const google::protobuf::Message &req) override;
     void read(std::shared_ptr<google::protobuf::Message> & msg, messages::MessageType * msg_type=nullptr) override;
@@ -274,7 +284,6 @@ namespace trezor {
     int get_interface() const;
     unsigned char get_endpoint() const;
 
-    int m_conn_count;
     std::shared_ptr<Protocol> m_proto;
 
     libusb_context        *m_usb_session;
@@ -285,7 +294,7 @@ namespace trezor {
     int m_bus_id;
     int m_device_addr;
 
-#ifdef WITH_TREZOR_DEBUG
+#ifdef WITH_TREZOR_DEBUGGING
     bool m_debug_mode;
 #endif
   };
@@ -309,7 +318,7 @@ namespace trezor {
   /**
    * Transforms path to the particular transport
    */
-  template<class t_transport>
+  template<class t_transport=Transport>
   std::shared_ptr<t_transport> transport_typed(const std::string & path){
     auto t = transport(path);
     if (!t){
@@ -362,7 +371,7 @@ namespace trezor {
    * @throws UnexpectedMessageException if the response message type is different than expected.
    * Exception contains message type and the message itself.
    */
-  template<class t_message>
+  template<class t_message=google::protobuf::Message>
   std::shared_ptr<t_message>
       exchange_message(Transport & transport, const google::protobuf::Message & req,
                        boost::optional<messages::MessageType> resp_type = boost::none)
diff --git a/src/device_trezor/trezor/trezor_defs.hpp b/src/device_trezor/trezor/trezor_defs.hpp
index 30e76eadc..f0697cdb5 100644
--- a/src/device_trezor/trezor/trezor_defs.hpp
+++ b/src/device_trezor/trezor/trezor_defs.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018, The Monero Project
+// Copyright (c) 2017-2019, The Monero Project
 //
 // All rights reserved.
 //