device/trezor: trezor support added

12 files changed, 2895 insertions, 0 deletions

diff --git a/src/device_trezor/trezor/exceptions.hpp b/src/device_trezor/trezor/exceptions.hpp
new file mode 100644
index 000000000..197dc43a4
--- /dev/null
+++ b/src/device_trezor/trezor/exceptions.hpp
@@ -0,0 +1,193 @@
+// 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_EXCEPTIONS_H
+#define MONERO_EXCEPTIONS_H
+
+#include <exception>
+#include <string>
+#include <boost/optional.hpp>
+
+namespace hw {
+namespace trezor {
+namespace exc {
+
+  class SecurityException : public std::exception {
+  protected:
+    boost::optional<std::string> reason;
+
+  public:
+    SecurityException(): reason("General Security exception"){}
+    explicit SecurityException(std::string what): reason(what){}
+
+    virtual const char* what() const throw() {
+      return reason.get().c_str();
+    }
+  };
+
+  class Poly1305TagInvalid: public SecurityException {
+  public:
+    using SecurityException::SecurityException;
+    Poly1305TagInvalid(): SecurityException("Poly1305 authentication tag invalid"){}
+  };
+
+  class TrezorException : public std::exception {
+  protected:
+    boost::optional<std::string> reason;
+
+  public:
+    TrezorException(): reason("General Trezor exception"){}
+    explicit TrezorException(std::string what): reason(what){}
+
+    virtual const char* what() const throw() {
+      return reason.get().c_str();
+    }
+  };
+
+  class CommunicationException: public TrezorException {
+  public:
+    using TrezorException::TrezorException;
+    CommunicationException(): TrezorException("Trezor communication error"){}
+  };
+
+  class EncodingException: public CommunicationException {
+  public:
+    using CommunicationException::CommunicationException;
+    EncodingException(): CommunicationException("Trezor message encoding error"){}
+  };
+
+  class NotConnectedException : public CommunicationException {
+  public:
+    using CommunicationException::CommunicationException;
+    NotConnectedException(): CommunicationException("Trezor not connected"){}
+  };
+
+  class DeviceNotResponsiveException : public CommunicationException {
+  public:
+    using CommunicationException::CommunicationException;
+    DeviceNotResponsiveException(): CommunicationException("Trezor does not respond to ping"){}
+  };
+
+  class DeviceAcquireException : public CommunicationException {
+  public:
+    using CommunicationException::CommunicationException;
+    DeviceAcquireException(): CommunicationException("Trezor could not be acquired"){}
+  };
+
+  class SessionException: public CommunicationException {
+  public:
+    using CommunicationException::CommunicationException;
+    SessionException(): CommunicationException("Trezor session expired"){}
+  };
+
+  class TimeoutException: public CommunicationException {
+  public:
+    using CommunicationException::CommunicationException;
+    TimeoutException(): CommunicationException("Trezor communication timeout"){}
+  };
+
+  class ProtocolException: public CommunicationException {
+  public:
+    using CommunicationException::CommunicationException;
+    ProtocolException(): CommunicationException("Trezor protocol error"){}
+  };
+
+  // Communication protocol namespace
+  // Separated to distinguish between client and Trezor side exceptions.
+namespace proto {
+
+  class SecurityException : public ProtocolException {
+  public:
+    using ProtocolException::ProtocolException;
+    SecurityException(): ProtocolException("Security assertion violated in the protocol"){}
+  };
+
+  class FailureException : public ProtocolException {
+  private:
+    boost::optional<uint32_t> code;
+    boost::optional<std::string> message;
+  public:
+    using ProtocolException::ProtocolException;
+    FailureException(): ProtocolException("Trezor returned failure"){}
+    FailureException(boost::optional<uint32_t> code,
+                     boost::optional<std::string> message)
+        : code(code), message(message) {
+      reason = "Trezor returned failure: code="
+               + (code ? std::to_string(code.get()) : "")
+               + ", message=" + (message ? message.get() : "");
+    };
+  };
+
+  class UnexpectedMessageException : public FailureException {
+  public:
+    using FailureException::FailureException;
+    UnexpectedMessageException(): FailureException("Trezor claims unexpected message received"){}
+  };
+
+  class CancelledException : public FailureException {
+  public:
+    using FailureException::FailureException;
+    CancelledException(): FailureException("Trezor returned: cancelled operation"){}
+  };
+
+  class PinExpectedException : public FailureException {
+  public:
+    using FailureException::FailureException;
+    PinExpectedException(): FailureException("Trezor claims PIN is expected"){}
+  };
+
+  class InvalidPinException : public FailureException {
+  public:
+    using FailureException::FailureException;
+    InvalidPinException(): FailureException("Trezor claims PIN is invalid"){}
+  };
+
+  class NotEnoughFundsException : public FailureException {
+  public:
+    using FailureException::FailureException;
+    NotEnoughFundsException(): FailureException("Trezor claims not enough funds"){}
+  };
+
+  class NotInitializedException : public FailureException {
+  public:
+    using FailureException::FailureException;
+    NotInitializedException(): FailureException("Trezor claims not initialized"){}
+  };
+
+  class FirmwareErrorException : public FailureException {
+  public:
+    using FailureException::FailureException;
+    FirmwareErrorException(): FailureException("Trezor returned firmware error"){}
+  };
+
+}
+}
+}
+}
+#endif //MONERO_EXCEPTIONS_H
diff --git a/src/device_trezor/trezor/messages/.gitignore b/src/device_trezor/trezor/messages/.gitignore
new file mode 100644
index 000000000..32f7a77e5
--- /dev/null
+++ b/src/device_trezor/trezor/messages/.gitignore
@@ -0,0 +1,2 @@
+# protobuf generated code
+*
diff --git a/src/device_trezor/trezor/messages_map.cpp b/src/device_trezor/trezor/messages_map.cpp
new file mode 100644
index 000000000..b0d1aa254
--- /dev/null
+++ b/src/device_trezor/trezor/messages_map.cpp
@@ -0,0 +1,125 @@
+// 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 "messages_map.hpp"
+#include "messages/messages.pb.h"
+#include "messages/messages-common.pb.h"
+#include "messages/messages-management.pb.h"
+#include "messages/messages-monero.pb.h"
+
+using namespace std;
+using namespace hw::trezor;
+
+namespace hw{
+namespace trezor
+{
+
+  const char * TYPE_PREFIX = "MessageType_";
+  const char * PACKAGES[] = {
+      "hw.trezor.messages.",
+      "hw.trezor.messages.common.",
+      "hw.trezor.messages.management.",
+      "hw.trezor.messages.monero."
+  };
+
+  google::protobuf::Message * MessageMapper::get_message(int wire_number) {
+    return MessageMapper::get_message(static_cast<messages::MessageType>(wire_number));
+  }
+
+  google::protobuf::Message * MessageMapper::get_message(messages::MessageType wire_number) {
+    const string &messageTypeName = hw::trezor::messages::MessageType_Name(wire_number);
+    if (messageTypeName.empty()) {
+      throw exc::EncodingException(std::string("Message descriptor not found: ") + std::to_string(wire_number));
+    }
+
+    string messageName = messageTypeName.substr(strlen(TYPE_PREFIX));
+    return MessageMapper::get_message(messageName);
+  }
+
+  google::protobuf::Message * MessageMapper::get_message(const std::string & msg_name) {
+    // Each package instantiation so lookup works
+    hw::trezor::messages::common::Success::default_instance();
+    hw::trezor::messages::management::Cancel::default_instance();
+    hw::trezor::messages::monero::MoneroGetAddress::default_instance();
+
+    google::protobuf::Descriptor const * desc = nullptr;
+    for(const string &text : PACKAGES){
+      desc = google::protobuf::DescriptorPool::generated_pool()
+          ->FindMessageTypeByName(text + msg_name);
+      if (desc != nullptr){
+        break;
+      }
+    }
+
+    if (desc == nullptr){
+      throw exc::EncodingException(std::string("Message not found: ") + msg_name);
+    }
+
+    google::protobuf::Message* message =
+        google::protobuf::MessageFactory::generated_factory()
+            ->GetPrototype(desc)->New();
+
+    return message;
+
+//    // CODEGEN way, fast
+//    switch(wire_number){
+//      case 501:
+//        return new messages::monero::MoneroTransactionSignRequest();
+//      default:
+//        throw std::runtime_error("not implemented");
+//    }
+//
+//    // CODEGEN message -> number: specification
+//    //    messages::MessageType get_message_wire_number(const messages::monero::MoneroTransactionSignRequest * msg) { return 501; }
+//    //    messages::MessageType get_message_wire_number(const messages::management::ping * msg)
+//
+  }
+
+  messages::MessageType MessageMapper::get_message_wire_number(const google::protobuf::Message * msg){
+    return MessageMapper::get_message_wire_number(msg->GetDescriptor()->name());
+  }
+
+  messages::MessageType MessageMapper::get_message_wire_number(const google::protobuf::Message & msg){
+    return MessageMapper::get_message_wire_number(msg.GetDescriptor()->name());
+  }
+
+  messages::MessageType MessageMapper::get_message_wire_number(const std::string & msg_name){
+    string enumMessageName = std::string(TYPE_PREFIX) + msg_name;
+
+    messages::MessageType res;
+    bool r = hw::trezor::messages::MessageType_Parse(enumMessageName, &res);
+    if (!r){
+      throw exc::EncodingException(std::string("Message ") + msg_name + " not found");
+    }
+
+    return res;
+  }
+
+}
+}
diff --git a/src/device_trezor/trezor/messages_map.hpp b/src/device_trezor/trezor/messages_map.hpp
new file mode 100644
index 000000000..f61338f09
--- /dev/null
+++ b/src/device_trezor/trezor/messages_map.hpp
@@ -0,0 +1,94 @@
+// 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_MESSAGES_MAP_H
+#define MONERO_MESSAGES_MAP_H
+
+#include <string>
+#include <type_traits>
+#include <memory>
+#include "exceptions.hpp"
+
+#include "trezor_defs.hpp"
+
+#include <google/protobuf/stubs/common.h>
+#include <google/protobuf/generated_message_util.h>
+#include <google/protobuf/repeated_field.h>
+#include <google/protobuf/extension_set.h>
+#include <google/protobuf/generated_enum_reflection.h>
+#include "google/protobuf/descriptor.pb.h"
+
+#include "messages/messages.pb.h"
+
+namespace hw {
+namespace trezor {
+
+  class MessageMapper{
+    public:
+      MessageMapper() {
+
+      }
+
+    static ::google::protobuf::Message * get_message(int wire_number);
+    static ::google::protobuf::Message * get_message(messages::MessageType);
+    static ::google::protobuf::Message * get_message(const std::string & msg_name);
+    static messages::MessageType get_message_wire_number(const google::protobuf::Message * msg);
+    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>
+    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>
+  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){
+      return nullptr;
+    }
+
+    return std::dynamic_pointer_cast<t_message>(in);
+  }
+
+  template<class t_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){
+      return nullptr;
+    }
+
+    return std::static_pointer_cast<t_message>(in);
+  }
+
+}}
+
+#endif //MONERO_MESSAGES_MAP_H
diff --git a/src/device_trezor/trezor/protocol.cpp b/src/device_trezor/trezor/protocol.cpp
new file mode 100644
index 000000000..c4a92426c
--- /dev/null
+++ b/src/device_trezor/trezor/protocol.cpp
@@ -0,0 +1,891 @@
+// 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 "protocol.hpp"
+#include <unordered_map>
+#include <set>
+#include <utility>
+#include <boost/endian/conversion.hpp>
+#include <common/apply_permutation.h>
+#include <ringct/rctSigs.h>
+#include <ringct/bulletproofs.h>
+#include "cryptonote_config.h"
+#include <sodium.h>
+#include <sodium/crypto_verify_32.h>
+#include <sodium/crypto_aead_chacha20poly1305.h>
+
+namespace hw{
+namespace trezor{
+namespace protocol{
+
+  std::string key_to_string(const ::crypto::ec_point & key){
+    return std::string(key.data, sizeof(key.data));
+  }
+
+  std::string key_to_string(const ::crypto::ec_scalar & key){
+    return std::string(key.data, sizeof(key.data));
+  }
+
+  std::string key_to_string(const ::crypto::hash & key){
+    return std::string(key.data, sizeof(key.data));
+  }
+
+  std::string key_to_string(const ::rct::key & key){
+    return std::string(reinterpret_cast<const char*>(key.bytes), sizeof(key.bytes));
+  }
+
+  void string_to_key(::crypto::ec_scalar & key, const std::string & str){
+    if (str.size() != sizeof(key.data)){
+      throw std::invalid_argument(std::string("Key has to have ") + std::to_string(sizeof(key.data)) + " B");
+    }
+    memcpy(key.data, str.data(), sizeof(key.data));
+  }
+
+  void string_to_key(::crypto::ec_point & key, const std::string & str){
+    if (str.size() != sizeof(key.data)){
+      throw std::invalid_argument(std::string("Key has to have ") + std::to_string(sizeof(key.data)) + " B");
+    }
+    memcpy(key.data, str.data(), sizeof(key.data));
+  }
+
+  void string_to_key(::rct::key & key, const std::string & str){
+    if (str.size() != sizeof(key.bytes)){
+      throw std::invalid_argument(std::string("Key has to have ") + std::to_string(sizeof(key.bytes)) + " B");
+    }
+    memcpy(key.bytes, str.data(), sizeof(key.bytes));
+  }
+
+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");
+    }
+
+    unsigned long long int cip_len = length;
+    auto r = crypto_aead_chacha20poly1305_ietf_decrypt(
+        reinterpret_cast<unsigned char *>(plaintext), &cip_len, nullptr,
+        static_cast<const unsigned char *>(ciphertext), length, nullptr, 0, iv, key);
+
+    if (r != 0){
+      throw exc::Poly1305TagInvalid();
+    }
+  }
+
+}
+}
+
+
+// Cold Key image sync
+namespace ki {
+
+  bool key_image_data(wallet_shim * wallet,
+                      const std::vector<tools::wallet2::transfer_details> & transfers,
+                      std::vector<MoneroTransferDetails> & res)
+  {
+    for(auto & td : transfers){
+      ::crypto::public_key tx_pub_key = wallet->get_tx_pub_key_from_received_outs(td);
+      const std::vector<::crypto::public_key> additional_tx_pub_keys = cryptonote::get_additional_tx_pub_keys_from_extra(td.m_tx);
+
+      res.emplace_back();
+      auto & cres = res.back();
+
+      cres.set_out_key(key_to_string(boost::get<cryptonote::txout_to_key>(td.m_tx.vout[td.m_internal_output_index].target).key));
+      cres.set_tx_pub_key(key_to_string(tx_pub_key));
+      cres.set_internal_output_index(td.m_internal_output_index);
+      for(auto & aux : additional_tx_pub_keys){
+        cres.add_additional_tx_pub_keys(key_to_string(aux));
+      }
+    }
+
+    return true;
+  }
+
+  std::string compute_hash(const MoneroTransferDetails & rr){
+    KECCAK_CTX kck;
+    uint8_t md[32];
+
+    CHECK_AND_ASSERT_THROW_MES(rr.out_key().size() == 32, "Invalid out_key size");
+    CHECK_AND_ASSERT_THROW_MES(rr.tx_pub_key().size() == 32, "Invalid tx_pub_key size");
+
+    keccak_init(&kck);
+    keccak_update(&kck, reinterpret_cast<const uint8_t *>(rr.out_key().data()), 32);
+    keccak_update(&kck, reinterpret_cast<const uint8_t *>(rr.tx_pub_key().data()), 32);
+    for (const auto &aux : rr.additional_tx_pub_keys()){
+      CHECK_AND_ASSERT_THROW_MES(aux.size() == 32, "Invalid aux size");
+      keccak_update(&kck, reinterpret_cast<const uint8_t *>(aux.data()), 32);
+    }
+
+    auto index_serialized = tools::get_varint_data(rr.internal_output_index());
+    keccak_update(&kck, reinterpret_cast<const uint8_t *>(index_serialized.data()), index_serialized.size());
+    keccak_finish(&kck, md);
+    return std::string(reinterpret_cast<const char*>(md), sizeof(md));
+  }
+
+  void generate_commitment(std::vector<MoneroTransferDetails> & mtds,
+                           const std::vector<tools::wallet2::transfer_details> & transfers,
+                           std::shared_ptr<messages::monero::MoneroKeyImageExportInitRequest> & req)
+  {
+    req = std::make_shared<messages::monero::MoneroKeyImageExportInitRequest>();
+
+    KECCAK_CTX kck;
+    uint8_t final_hash[32];
+    keccak_init(&kck);
+
+    for(auto &cur : mtds){
+      auto hash = compute_hash(cur);
+      keccak_update(&kck, reinterpret_cast<const uint8_t *>(hash.data()), hash.size());
+    }
+    keccak_finish(&kck, final_hash);
+
+    req = std::make_shared<messages::monero::MoneroKeyImageExportInitRequest>();
+    req->set_hash(std::string(reinterpret_cast<const char*>(final_hash), 32));
+    req->set_num(transfers.size());
+
+    std::unordered_map<uint32_t, std::set<uint32_t>> sub_indices;
+    for (auto &cur : transfers){
+      auto search = sub_indices.emplace(cur.m_subaddr_index.major, std::set<uint32_t>());
+      auto & st = search.first->second;
+      st.insert(cur.m_subaddr_index.minor);
+    }
+
+    for (auto& x: sub_indices){
+      auto subs = req->add_subs();
+      subs->set_account(x.first);
+      for(auto minor : x.second){
+        subs->add_minor_indices(minor);
+      }
+    }
+  }
+
+}
+
+// Cold transaction signing
+namespace tx {
+
+  void translate_address(MoneroAccountPublicAddress * dst, const cryptonote::account_public_address * src){
+    dst->set_view_public_key(key_to_string(src->m_view_public_key));
+    dst->set_spend_public_key(key_to_string(src->m_spend_public_key));
+  }
+
+  void translate_dst_entry(MoneroTransactionDestinationEntry * dst, const cryptonote::tx_destination_entry * src){
+    dst->set_amount(src->amount);
+    dst->set_is_subaddress(src->is_subaddress);
+    translate_address(dst->mutable_addr(), &(src->addr));
+  }
+
+  void translate_src_entry(MoneroTransactionSourceEntry * dst, const cryptonote::tx_source_entry * src){
+    for(auto & cur : src->outputs){
+      auto out = dst->add_outputs();
+      out->set_idx(cur.first);
+      translate_rct_key(out->mutable_key(), &(cur.second));
+    }
+
+    dst->set_real_output(src->real_output);
+    dst->set_real_out_tx_key(key_to_string(src->real_out_tx_key));
+    for(auto & cur : src->real_out_additional_tx_keys){
+      dst->add_real_out_additional_tx_keys(key_to_string(cur));
+    }
+
+    dst->set_real_output_in_tx_index(src->real_output_in_tx_index);
+    dst->set_amount(src->amount);
+    dst->set_rct(src->rct);
+    dst->set_mask(key_to_string(src->mask));
+    translate_klrki(dst->mutable_multisig_klrki(), &(src->multisig_kLRki));
+  }
+
+  void translate_klrki(MoneroMultisigKLRki * dst, const rct::multisig_kLRki * src){
+    dst->set_k(key_to_string(src->k));
+    dst->set_l(key_to_string(src->L));
+    dst->set_r(key_to_string(src->R));
+    dst->set_ki(key_to_string(src->ki));
+  }
+
+  void translate_rct_key(MoneroRctKey * dst, const rct::ctkey * src){
+    dst->set_dest(key_to_string(src->dest));
+    dst->set_commitment(key_to_string(src->mask));
+  }
+
+  std::string hash_addr(const MoneroAccountPublicAddress * addr, boost::optional<uint64_t> amount, boost::optional<bool> is_subaddr){
+    return hash_addr(addr->spend_public_key(), addr->view_public_key(), amount, is_subaddr);
+  }
+
+  std::string hash_addr(const std::string & spend_key, const std::string & view_key, boost::optional<uint64_t> amount, boost::optional<bool> is_subaddr){
+    ::crypto::public_key spend{}, view{};
+    if (spend_key.size() != 32 || view_key.size() != 32){
+      throw std::invalid_argument("Public keys have invalid sizes");
+    }
+
+    memcpy(spend.data, spend_key.data(), 32);
+    memcpy(view.data, view_key.data(), 32);
+    return hash_addr(&spend, &view, amount, is_subaddr);
+  }
+
+  std::string hash_addr(const ::crypto::public_key * spend_key, const ::crypto::public_key * view_key, boost::optional<uint64_t> amount, boost::optional<bool> is_subaddr){
+    char buff[64+8+1];
+    size_t offset = 0;
+
+    memcpy(buff + offset, spend_key->data, 32); offset += 32;
+    memcpy(buff + offset, view_key->data, 32); offset += 32;
+
+    if (amount){
+      memcpy(buff + offset, (uint8_t*) &(amount.get()), sizeof(amount.get())); offset += sizeof(amount.get());
+    }
+
+    if (is_subaddr){
+      buff[offset] = is_subaddr.get();
+      offset += 1;
+    }
+
+    return std::string(buff, offset);
+  }
+
+  TData::TData() {
+    in_memory = false;
+    rsig_type = 0;
+    cur_input_idx = 0;
+    cur_output_idx = 0;
+    cur_batch_idx = 0;
+    cur_output_in_batch_idx = 0;
+  }
+
+  Signer::Signer(wallet_shim *wallet2, const unsigned_tx_set * unsigned_tx, size_t tx_idx, hw::tx_aux_data * aux_data) {
+    m_wallet2 = wallet2;
+    m_unsigned_tx = unsigned_tx;
+    m_aux_data = aux_data;
+    m_tx_idx = tx_idx;
+    m_ct.tx_data = cur_tx();
+    m_multisig = false;
+  }
+
+  void Signer::extract_payment_id(){
+    const std::vector<uint8_t>& tx_extra = cur_tx().extra;
+    m_ct.tsx_data.set_payment_id("");
+
+    std::vector<cryptonote::tx_extra_field> tx_extra_fields;
+    cryptonote::parse_tx_extra(tx_extra, tx_extra_fields); // ok if partially parsed
+    cryptonote::tx_extra_nonce extra_nonce;
+
+    ::crypto::hash payment_id{};
+    if (find_tx_extra_field_by_type(tx_extra_fields, extra_nonce))
+    {
+      ::crypto::hash8 payment_id8{};
+      if(cryptonote::get_encrypted_payment_id_from_tx_extra_nonce(extra_nonce.nonce, payment_id8))
+      {
+        m_ct.tsx_data.set_payment_id(std::string(payment_id8.data, 8));
+      }
+      else if (cryptonote::get_payment_id_from_tx_extra_nonce(extra_nonce.nonce, payment_id))
+      {
+        m_ct.tsx_data.set_payment_id(std::string(payment_id.data, 32));
+      }
+    }
+  }
+
+  static unsigned get_rsig_type(bool use_bulletproof, size_t num_outputs){
+    if (!use_bulletproof){
+      return rct::RangeProofBorromean;
+    } else if (num_outputs > BULLETPROOF_MAX_OUTPUTS){
+      return rct::RangeProofMultiOutputBulletproof;
+    } else {
+      return rct::RangeProofPaddedBulletproof;
+    }
+  }
+
+  static void generate_rsig_batch_sizes(std::vector<uint64_t> &batches, unsigned rsig_type, size_t num_outputs){
+    size_t amount_batched = 0;
+
+    while(amount_batched < num_outputs){
+      if (rsig_type == rct::RangeProofBorromean || rsig_type == rct::RangeProofBulletproof) {
+        batches.push_back(1);
+        amount_batched += 1;
+
+      } else if (rsig_type == rct::RangeProofPaddedBulletproof){
+        if (num_outputs > BULLETPROOF_MAX_OUTPUTS){
+          throw std::invalid_argument("BP padded can support only BULLETPROOF_MAX_OUTPUTS statements");
+        }
+        batches.push_back(num_outputs);
+        amount_batched += num_outputs;
+
+      } else if (rsig_type == rct::RangeProofMultiOutputBulletproof){
+        size_t batch_size = 1;
+        while (batch_size * 2 + amount_batched <= num_outputs && batch_size * 2 <= BULLETPROOF_MAX_OUTPUTS){
+          batch_size *= 2;
+        }
+        batch_size = std::min(batch_size, num_outputs - amount_batched);
+        batches.push_back(batch_size);
+        amount_batched += batch_size;
+
+      } else {
+        throw std::invalid_argument("Unknown rsig type");
+      }
+    }
+  }
+
+  void Signer::compute_integrated_indices(TsxData * tsx_data){
+    if (m_aux_data == nullptr || m_aux_data->tx_recipients.empty()){
+      return;
+    }
+
+    auto & chg = tsx_data->change_dts();
+    std::string change_hash = hash_addr(&chg.addr(), chg.amount(), chg.is_subaddress());
+
+    std::vector<uint32_t> integrated_indices;
+    std::set<std::string> integrated_hashes;
+    for (auto & cur : m_aux_data->tx_recipients){
+      if (!cur.has_payment_id){
+        continue;
+      }
+      integrated_hashes.emplace(hash_addr(&cur.address.m_spend_public_key, &cur.address.m_view_public_key));
+    }
+
+    ssize_t idx = -1;
+    for (auto & cur : tsx_data->outputs()){
+      idx += 1;
+
+      std::string c_hash = hash_addr(&cur.addr(), cur.amount(), cur.is_subaddress());
+      if (c_hash == change_hash || cur.is_subaddress()){
+        continue;
+      }
+
+      c_hash = hash_addr(&cur.addr());
+      if (integrated_hashes.find(c_hash) != integrated_hashes.end()){
+        integrated_indices.push_back((uint32_t)idx);
+      }
+    }
+
+    if (!integrated_indices.empty()){
+      assign_to_repeatable(tsx_data->mutable_integrated_indices(), integrated_indices.begin(), integrated_indices.end());
+    }
+  }
+
+  std::shared_ptr<messages::monero::MoneroTransactionInitRequest> Signer::step_init(){
+    // extract payment ID from construction data
+    auto & tsx_data = m_ct.tsx_data;
+    auto & tx = cur_tx();
+
+    m_ct.tx.version = 2;
+    m_ct.tx.unlock_time = tx.unlock_time;
+
+    tsx_data.set_version(1);
+    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));
+    tsx_data.set_account(tx.subaddr_account);
+    assign_to_repeatable(tsx_data.mutable_minor_indices(), tx.subaddr_indices.begin(), tx.subaddr_indices.end());
+
+    // Rsig decision
+    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);
+
+    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());
+
+    translate_dst_entry(tsx_data.mutable_change_dts(), &(tx.change_dts));
+    for(auto & cur : tx.splitted_dsts){
+      auto dst = tsx_data.mutable_outputs()->Add();
+      translate_dst_entry(dst, &cur);
+    }
+
+    compute_integrated_indices(&tsx_data);
+
+    int64_t fee = 0;
+    for(auto & cur_in : tx.sources){
+      fee += cur_in.amount;
+    }
+    for(auto & cur_out : tx.splitted_dsts){
+      fee -= cur_out.amount;
+    }
+    if (fee < 0){
+      throw std::invalid_argument("Fee cannot be negative");
+    }
+
+    tsx_data.set_fee(static_cast<google::protobuf::uint64>(fee));
+    this->extract_payment_id();
+
+    auto init_req = std::make_shared<messages::monero::MoneroTransactionInitRequest>();
+    init_req->set_version(0);
+    init_req->mutable_tsx_data()->CopyFrom(tsx_data);
+    return init_req;
+  }
+
+  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());
+    }
+
+    assign_from_repeatable(&(m_ct.tx_out_entr_hmacs), ack->hmacs().begin(), ack->hmacs().end());
+  }
+
+  std::shared_ptr<messages::monero::MoneroTransactionSetInputRequest> Signer::step_set_input(size_t idx){
+    CHECK_AND_ASSERT_THROW_MES(idx < cur_tx().sources.size(), "Invalid source index");
+    m_ct.cur_input_idx = idx;
+    auto res = std::make_shared<messages::monero::MoneroTransactionSetInputRequest>();
+    translate_src_entry(res->mutable_src_entr(), &(cur_tx().sources[idx]));
+    return res;
+  }
+
+  void Signer::step_set_input_ack(std::shared_ptr<const messages::monero::MoneroTransactionSetInputAck> ack){
+    auto & vini_str = ack->vini();
+
+    cryptonote::txin_v vini;
+    if (!cn_deserialize(vini_str.data(), vini_str.size(), vini)){
+      throw exc::ProtocolException("Cannot deserialize vin[i]");
+    }
+
+    m_ct.tx.vin.emplace_back(vini);
+    m_ct.tx_in_hmacs.push_back(ack->vini_hmac());
+    m_ct.pseudo_outs.push_back(ack->pseudo_out());
+    m_ct.pseudo_outs_hmac.push_back(ack->pseudo_out_hmac());
+    m_ct.alphas.push_back(ack->pseudo_out_alpha());
+    m_ct.spend_encs.push_back(ack->spend_key());
+  }
+
+  void Signer::sort_ki(){
+    const size_t input_size = cur_tx().sources.size();
+
+    m_ct.source_permutation.clear();
+    for (size_t n = 0; n < input_size; ++n){
+      m_ct.source_permutation.push_back(n);
+    }
+
+    CHECK_AND_ASSERT_THROW_MES(m_ct.tx.vin.size() == input_size, "Invalid vector size");
+    std::sort(m_ct.source_permutation.begin(), m_ct.source_permutation.end(), [&](const size_t i0, const size_t i1) {
+      const cryptonote::txin_to_key &tk0 = boost::get<cryptonote::txin_to_key>(m_ct.tx.vin[i0]);
+      const cryptonote::txin_to_key &tk1 = boost::get<cryptonote::txin_to_key>(m_ct.tx.vin[i1]);
+      return memcmp(&tk0.k_image, &tk1.k_image, sizeof(tk0.k_image)) > 0;
+    });
+
+    CHECK_AND_ASSERT_THROW_MES(m_ct.tx_in_hmacs.size() == input_size, "Invalid vector size");
+    CHECK_AND_ASSERT_THROW_MES(m_ct.pseudo_outs.size() == input_size, "Invalid vector size");
+    CHECK_AND_ASSERT_THROW_MES(m_ct.pseudo_outs_hmac.size() == input_size, "Invalid vector size");
+    CHECK_AND_ASSERT_THROW_MES(m_ct.alphas.size() == input_size, "Invalid vector size");
+    CHECK_AND_ASSERT_THROW_MES(m_ct.spend_encs.size() == input_size, "Invalid vector size");
+    CHECK_AND_ASSERT_THROW_MES(m_ct.tx_data.sources.size() == input_size, "Invalid vector size");
+
+    tools::apply_permutation(m_ct.source_permutation, [&](size_t i0, size_t i1){
+      std::swap(m_ct.tx.vin[i0], m_ct.tx.vin[i1]);
+      std::swap(m_ct.tx_in_hmacs[i0], m_ct.tx_in_hmacs[i1]);
+      std::swap(m_ct.pseudo_outs[i0], m_ct.pseudo_outs[i1]);
+      std::swap(m_ct.pseudo_outs_hmac[i0], m_ct.pseudo_outs_hmac[i1]);
+      std::swap(m_ct.alphas[i0], m_ct.alphas[i1]);
+      std::swap(m_ct.spend_encs[i0], m_ct.spend_encs[i1]);
+      std::swap(m_ct.tx_data.sources[i0], m_ct.tx_data.sources[i1]);
+    });
+  }
+
+  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());
+
+    return res;
+  }
+
+  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");
+
+    m_ct.cur_input_idx = idx;
+    auto tx = m_ct.tx_data;
+    auto res = std::make_shared<messages::monero::MoneroTransactionInputViniRequest>();
+    auto & vini = m_ct.tx.vin[idx];
+    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()) {
+      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;
+  }
+
+  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(){
+    return std::make_shared<messages::monero::MoneroTransactionAllInputsSetRequest>();
+  }
+
+  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");
+      }
+
+      auto & rsig_data = ack->rsig_data();
+      if (!rsig_data.has_mask()){
+        throw exc::ProtocolException("Gamma masks not present in offloaded version");
+      }
+
+      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");
+
+    m_ct.cur_output_idx = idx;
+    m_ct.cur_output_in_batch_idx += 1;   // assumes sequential call to step_set_output()
+
+    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]);
+
+    // 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);
+    }
+
+    return res;
+  }
+
+  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{};
+
+    bool has_rsig = false;
+    std::string rsig_buff;
+
+    if (ack->has_rsig_data()){
+      auto & rsig_data = ack->rsig_data();
+
+      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 (!cn_deserialize(ack->tx_out(), tx_out)){
+      throw exc::ProtocolException("Cannot deserialize vout[i]");
+    }
+
+    if (!cn_deserialize(ack->out_pk(), out_pk)){
+      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 (has_rsig && is_req_bulletproof() && !cn_deserialize(rsig_buff, bproof)){
+      throw exc::ProtocolException("Cannot deserialize bulletproof rangesig");
+    }
+
+    m_ct.tx.vout.emplace_back(tx_out);
+    m_ct.tx_out_hmacs.push_back(ack->vouti_hmac());
+    m_ct.tx_out_pk.emplace_back(out_pk);
+    m_ct.tx_out_ecdh.emplace_back(ecdh);
+
+    if (!has_rsig){
+      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");
+
+        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");
+      }
+
+    } else {
+      m_ct.tx_out_rsigs.emplace_back(range_sig);
+
+      if (!rct::verRange(out_pk.mask, boost::get<rct::rangeSig>(m_ct.tx_out_rsigs.back()))) {
+        throw exc::ProtocolException("Returned range signature is invalid");
+      }
+    }
+
+    m_ct.cur_batch_idx += 1;
+    m_ct.cur_output_in_batch_idx = 0;
+  }
+
+  std::shared_ptr<messages::monero::MoneroTransactionAllOutSetRequest> Signer::step_all_outs_set(){
+    return std::make_shared<messages::monero::MoneroTransactionAllOutSetRequest>();
+  }
+
+  void Signer::step_all_outs_set_ack(std::shared_ptr<const messages::monero::MoneroTransactionAllOutSetAck> ack, hw::device &hwdev){
+    m_ct.rv = std::make_shared<rct::rctSig>();
+    m_ct.rv->txnFee = ack->rv().txn_fee();
+    m_ct.rv->type = static_cast<uint8_t>(ack->rv().rv_type());
+    string_to_key(m_ct.rv->message, ack->rv().message());
+
+    // Extra copy
+    m_ct.tx.extra.clear();
+    auto extra = ack->extra();
+    auto extra_data = extra.data();
+    m_ct.tx.extra.reserve(extra.size());
+    for(size_t i = 0; i < extra.size(); ++i){
+      m_ct.tx.extra.push_back(static_cast<uint8_t>(extra_data[i]));
+    }
+
+    ::crypto::hash tx_prefix_hash{};
+    cryptonote::get_transaction_prefix_hash(m_ct.tx, tx_prefix_hash);
+    m_ct.tx_prefix_hash = key_to_string(tx_prefix_hash);
+    if (crypto_verify_32(reinterpret_cast<const unsigned char *>(tx_prefix_hash.data),
+        reinterpret_cast<const unsigned char *>(ack->tx_prefix_hash().data()))){
+      throw exc::proto::SecurityException("Transaction prefix has does not match to the computed value");
+    }
+
+    // RctSig
+    auto num_sources = m_ct.tx_data.sources.size();
+    if (is_simple() || is_req_bulletproof()){
+      auto dst = &m_ct.rv->pseudoOuts;
+      if (is_bulletproof()){
+        dst = &m_ct.rv->p.pseudoOuts;
+      }
+
+      dst->clear();
+      for (const auto &pseudo_out : m_ct.pseudo_outs) {
+        dst->emplace_back();
+        string_to_key(dst->back(), pseudo_out);
+      }
+
+      m_ct.rv->mixRing.resize(num_sources);
+    } else {
+      m_ct.rv->mixRing.resize(m_ct.tsx_data.mixin());
+      m_ct.rv->mixRing[0].resize(num_sources);
+    }
+
+    CHECK_AND_ASSERT_THROW_MES(m_ct.tx_out_pk.size() == m_ct.tx_out_ecdh.size(), "Invalid vector sizes");
+    for(size_t i = 0; i < m_ct.tx_out_ecdh.size(); ++i){
+      m_ct.rv->outPk.push_back(m_ct.tx_out_pk[i]);
+      m_ct.rv->ecdhInfo.push_back(m_ct.tx_out_ecdh[i]);
+    }
+
+    for(size_t i = 0; i < m_ct.tx_out_rsigs.size(); ++i){
+      if (is_bulletproof()){
+        m_ct.rv->p.bulletproofs.push_back(boost::get<rct::Bulletproof>(m_ct.tx_out_rsigs[i]));
+      } else {
+        m_ct.rv->p.rangeSigs.push_back(boost::get<rct::rangeSig>(m_ct.tx_out_rsigs[i]));
+      }
+    }
+
+    rct::key hash_computed = rct::get_pre_mlsag_hash(*(m_ct.rv), hwdev);
+    auto & hash = ack->full_message_hash();
+
+    if (hash.size() != 32){
+      throw exc::ProtocolException("Returned mlsag hash has invalid size");
+    }
+
+    if (crypto_verify_32(reinterpret_cast<const unsigned char *>(hash_computed.bytes),
+                         reinterpret_cast<const unsigned char *>(hash.data()))){
+      throw exc::proto::SecurityException("Computed MLSAG does not match");
+    }
+  }
+
+  std::shared_ptr<messages::monero::MoneroTransactionSignInputRequest> Signer::step_sign_input(size_t idx){
+    m_ct.cur_input_idx = idx;
+
+    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");
+    CHECK_AND_ASSERT_THROW_MES(idx < m_ct.alphas.size(), "Invalid transaction index");
+    CHECK_AND_ASSERT_THROW_MES(idx < m_ct.spend_encs.size(), "Invalid transaction index");
+
+    auto res = std::make_shared<messages::monero::MoneroTransactionSignInputRequest>();
+    translate_src_entry(res->mutable_src_entr(), &(m_ct.tx_data.sources[idx]));
+    res->set_vini(cryptonote::t_serializable_object_to_blob(m_ct.tx.vin[idx]));
+    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]);
+    }
+    return res;
+  }
+
+  void Signer::step_sign_input_ack(std::shared_ptr<const messages::monero::MoneroTransactionSignInputAck> ack){
+    rct::mgSig mg;
+    if (!cn_deserialize(ack->signature(), mg)){
+      throw exc::ProtocolException("Cannot deserialize mg[i]");
+    }
+
+    m_ct.rv->p.MGs.push_back(mg);
+  }
+
+  std::shared_ptr<messages::monero::MoneroTransactionFinalRequest> Signer::step_final(){
+    m_ct.tx.rct_signatures = *(m_ct.rv);
+    return std::make_shared<messages::monero::MoneroTransactionFinalRequest>();
+  }
+
+  void Signer::step_final_ack(std::shared_ptr<const messages::monero::MoneroTransactionFinalAck> ack){
+    if (m_multisig){
+      auto & cout_key = ack->cout_key();
+      for(auto & cur : m_ct.couts){
+        if (cur.size() != 12 + 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);
+        m_ct.couts_dec.emplace_back(buff, 32);
+      }
+    }
+
+    m_ct.enc_salt1 = ack->salt();
+    m_ct.enc_salt2 = ack->rand_mult();
+    m_ct.enc_keys = ack->tx_enc_keys();
+  }
+
+  std::string Signer::store_tx_aux_info(){
+    rapidjson::StringBuffer sb;
+    rapidjson::Writer<rapidjson::StringBuffer> writer(sb);
+
+    rapidjson::Document json;
+    json.SetObject();
+
+    rapidjson::Value valueS(rapidjson::kStringType);
+    rapidjson::Value valueI(rapidjson::kNumberType);
+
+    valueI.SetInt(1);
+    json.AddMember("version", valueI, json.GetAllocator());
+
+    valueS.SetString(m_ct.enc_salt1.c_str(), m_ct.enc_salt1.size());
+    json.AddMember("salt1", valueS, json.GetAllocator());
+
+    valueS.SetString(m_ct.enc_salt2.c_str(), m_ct.enc_salt2.size());
+    json.AddMember("salt2", valueS, json.GetAllocator());
+
+    valueS.SetString(m_ct.enc_keys.c_str(), m_ct.enc_keys.size());
+    json.AddMember("enc_keys", valueS, json.GetAllocator());
+
+    json.Accept(writer);
+    return sb.GetString();
+  }
+
+
+}
+}
+}
+}
diff --git a/src/device_trezor/trezor/protocol.hpp b/src/device_trezor/trezor/protocol.hpp
new file mode 100644
index 000000000..99211efed
--- /dev/null
+++ b/src/device_trezor/trezor/protocol.hpp
@@ -0,0 +1,300 @@
+// 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_PROTOCOL_H
+#define MONERO_PROTOCOL_H
+
+#include "trezor_defs.hpp"
+#include "device/device_cold.hpp"
+#include "messages_map.hpp"
+#include "transport.hpp"
+#include "wallet/wallet2.h"
+
+namespace hw{
+namespace trezor{
+namespace protocol{
+
+  std::string key_to_string(const ::crypto::ec_point & key);
+  std::string key_to_string(const ::crypto::ec_scalar & key);
+  std::string key_to_string(const ::crypto::hash & key);
+  std::string key_to_string(const ::rct::key & key);
+
+  void string_to_key(::crypto::ec_scalar & key, const std::string & str);
+  void string_to_key(::crypto::ec_point & key, const std::string & str);
+  void string_to_key(::rct::key & key, const std::string & str);
+
+  template<class sub_t, class InputIterator>
+  void assign_to_repeatable(::google::protobuf::RepeatedField<sub_t> * dst, const InputIterator begin, const InputIterator end){
+    for (InputIterator it = begin; it != end; it++) {
+      auto s = dst->Add();
+      *s = *it;
+    }
+  }
+
+  template<class sub_t, class InputIterator>
+  void assign_from_repeatable(std::vector<sub_t> * dst, const InputIterator begin, const InputIterator end){
+    for (InputIterator it = begin; it != end; it++) {
+      dst->push_back(*it);
+    }
+  };
+
+  template<typename T>
+  bool cn_deserialize(const void * buff, size_t len, T & dst){
+    std::stringstream ss;
+    ss.write(static_cast<const char *>(buff), len);  //ss << tx_blob;
+    binary_archive<false> ba(ss);
+    bool r = ::serialization::serialize(ba, dst);
+    return r;
+  }
+
+  template<typename T>
+  bool cn_deserialize(const std::string & str, T & dst){
+    return cn_deserialize(str.data(), str.size(), dst);
+  }
+
+  template<typename T>
+  std::string cn_serialize(T & obj){
+    std::ostringstream oss;
+    binary_archive<true> oar(oss);
+    bool success = ::serialization::serialize(oar, obj);
+    if (!success){
+      throw exc::EncodingException("Could not CN serialize given object");
+    }
+    return oss.str();
+  }
+
+// Crypto / encryption
+namespace crypto {
+namespace chacha {
+
+  /**
+   * 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);
+
+}
+}
+
+
+// Cold Key image sync
+namespace ki {
+
+  using MoneroTransferDetails = messages::monero::MoneroKeyImageSyncStepRequest_MoneroTransferDetails;
+  using MoneroSubAddressIndicesList = messages::monero::MoneroKeyImageExportInitRequest_MoneroSubAddressIndicesList;
+  using MoneroExportedKeyImage = messages::monero::MoneroKeyImageSyncStepAck_MoneroExportedKeyImage;
+  using exported_key_image = hw::device_cold::exported_key_image;
+
+  /**
+   * Converts transfer details to the MoneroTransferDetails required for KI sync
+   */
+  bool key_image_data(wallet_shim * wallet,
+                      const std::vector<tools::wallet2::transfer_details> & transfers,
+                      std::vector<MoneroTransferDetails> & res);
+
+  /**
+   * Computes a hash over MoneroTransferDetails. Commitment used in the KI sync.
+   */
+  std::string compute_hash(const MoneroTransferDetails & rr);
+
+  /**
+   * Generates KI sync request with commitments computed.
+   */
+  void generate_commitment(std::vector<MoneroTransferDetails> & mtds,
+                           const std::vector<tools::wallet2::transfer_details> & transfers,
+                           std::shared_ptr<messages::monero::MoneroKeyImageExportInitRequest> & req);
+
+}
+
+// Cold transaction signing
+namespace tx {
+  using TsxData = messages::monero::MoneroTransactionInitRequest_MoneroTransactionData;
+  using MoneroTransactionDestinationEntry = messages::monero::MoneroTransactionDestinationEntry;
+  using MoneroAccountPublicAddress = messages::monero::MoneroTransactionDestinationEntry_MoneroAccountPublicAddress;
+  using MoneroTransactionSourceEntry = messages::monero::MoneroTransactionSourceEntry;
+  using MoneroMultisigKLRki = messages::monero::MoneroTransactionSourceEntry_MoneroMultisigKLRki;
+  using MoneroOutputEntry = messages::monero::MoneroTransactionSourceEntry_MoneroOutputEntry;
+  using MoneroRctKey = messages::monero::MoneroTransactionSourceEntry_MoneroOutputEntry_MoneroRctKeyPublic;
+  using MoneroRsigData = messages::monero::MoneroTransactionRsigData;
+
+  using tx_construction_data = tools::wallet2::tx_construction_data;
+  using unsigned_tx_set = tools::wallet2::unsigned_tx_set;
+
+  void translate_address(MoneroAccountPublicAddress * dst, const cryptonote::account_public_address * src);
+  void translate_dst_entry(MoneroTransactionDestinationEntry * dst, const cryptonote::tx_destination_entry * src);
+  void translate_src_entry(MoneroTransactionSourceEntry * dst, const cryptonote::tx_source_entry * src);
+  void translate_klrki(MoneroMultisigKLRki * dst, const rct::multisig_kLRki * src);
+  void translate_rct_key(MoneroRctKey * dst, const rct::ctkey * src);
+  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);
+
+  typedef boost::variant<rct::rangeSig, rct::Bulletproof> rsig_v;
+
+  /**
+   * Transaction signer state holder.
+   */
+  class TData {
+  public:
+    TsxData tsx_data;
+    tx_construction_data tx_data;
+    cryptonote::transaction tx;
+    bool in_memory;
+    unsigned rsig_type;
+    std::vector<uint64_t> grouping_vct;
+    std::shared_ptr<MoneroRsigData> rsig_param;
+    size_t cur_input_idx;
+    size_t cur_output_idx;
+    size_t cur_batch_idx;
+    size_t cur_output_in_batch_idx;
+
+    std::vector<std::string> tx_in_hmacs;
+    std::vector<std::string> tx_out_entr_hmacs;
+    std::vector<std::string> tx_out_hmacs;
+    std::vector<rsig_v> tx_out_rsigs;
+    std::vector<rct::ctkey> tx_out_pk;
+    std::vector<rct::ecdhTuple> tx_out_ecdh;
+    std::vector<size_t> source_permutation;
+    std::vector<std::string> alphas;
+    std::vector<std::string> spend_encs;
+    std::vector<std::string> pseudo_outs;
+    std::vector<std::string> pseudo_outs_hmac;
+    std::vector<std::string> couts;
+    std::vector<std::string> couts_dec;
+    std::vector<rct::key> rsig_gamma;
+    std::string tx_prefix_hash;
+    std::string enc_salt1;
+    std::string enc_salt2;
+    std::string enc_keys;
+
+    std::shared_ptr<rct::rctSig> rv;
+
+    TData();
+  };
+
+  class Signer {
+  private:
+    TData m_ct;
+    wallet_shim * m_wallet2;
+
+    size_t m_tx_idx;
+    const unsigned_tx_set * m_unsigned_tx;
+    hw::tx_aux_data * m_aux_data;
+
+    bool m_multisig;
+
+    const tx_construction_data & cur_tx(){
+      CHECK_AND_ASSERT_THROW_MES(m_tx_idx < m_unsigned_tx->txes.size(), "Invalid transaction index");
+      return m_unsigned_tx->txes[m_tx_idx];
+    }
+
+    void extract_payment_id();
+    void compute_integrated_indices(TsxData * tsx_data);
+
+  public:
+    Signer(wallet_shim * wallet2, const unsigned_tx_set * unsigned_tx, size_t tx_idx = 0, hw::tx_aux_data * aux_data = nullptr);
+
+    std::shared_ptr<messages::monero::MoneroTransactionInitRequest> step_init();
+    void step_init_ack(std::shared_ptr<const messages::monero::MoneroTransactionInitAck> ack);
+
+    std::shared_ptr<messages::monero::MoneroTransactionSetInputRequest> step_set_input(size_t idx);
+    void step_set_input_ack(std::shared_ptr<const messages::monero::MoneroTransactionSetInputAck> ack);
+
+    void sort_ki();
+    std::shared_ptr<messages::monero::MoneroTransactionInputsPermutationRequest> step_permutation();
+    void step_permutation_ack(std::shared_ptr<const messages::monero::MoneroTransactionInputsPermutationAck> ack);
+
+    std::shared_ptr<messages::monero::MoneroTransactionInputViniRequest> step_set_vini_input(size_t idx);
+    void step_set_vini_input_ack(std::shared_ptr<const messages::monero::MoneroTransactionInputViniAck> ack);
+
+    std::shared_ptr<messages::monero::MoneroTransactionAllInputsSetRequest> step_all_inputs_set();
+    void step_all_inputs_set_ack(std::shared_ptr<const messages::monero::MoneroTransactionAllInputsSetAck> ack);
+
+    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::MoneroTransactionAllOutSetRequest> step_all_outs_set();
+    void step_all_outs_set_ack(std::shared_ptr<const messages::monero::MoneroTransactionAllOutSetAck> ack, hw::device &hwdev);
+
+    std::shared_ptr<messages::monero::MoneroTransactionSignInputRequest> step_sign_input(size_t idx);
+    void step_sign_input_ack(std::shared_ptr<const messages::monero::MoneroTransactionSignInputAck> ack);
+
+    std::shared_ptr<messages::monero::MoneroTransactionFinalRequest> step_final();
+    void step_final_ack(std::shared_ptr<const messages::monero::MoneroTransactionFinalAck> ack);
+
+    std::string store_tx_aux_info();
+
+    bool in_memory() const {
+      return m_ct.in_memory;
+    }
+
+    bool is_simple() const {
+      if (!m_ct.rv){
+        throw std::invalid_argument("RV not initialized");
+      }
+      auto tp = m_ct.rv->type;
+      return tp == rct::RCTTypeSimple;
+    }
+
+    bool is_req_bulletproof() const {
+      return m_ct.tx_data.use_bulletproofs;
+    }
+
+    bool is_bulletproof() const {
+      if (!m_ct.rv){
+        throw std::invalid_argument("RV not initialized");
+      }
+      auto tp = m_ct.rv->type;
+      return tp == rct::RCTTypeBulletproof;
+    }
+
+    bool is_offloading() const {
+      return m_ct.rsig_param && m_ct.rsig_param->offload_type() != 0;
+    }
+
+    size_t num_outputs() const {
+      return m_ct.tx_data.splitted_dsts.size();
+    }
+
+    size_t num_inputs() const {
+      return m_ct.tx_data.sources.size();
+    }
+
+    const TData & tdata() const {
+      return m_ct;
+    }
+  };
+
+}
+
+}
+}
+}
+
+
+#endif //MONERO_PROTOCOL_H
diff --git a/src/device_trezor/trezor/tools/README.md b/src/device_trezor/trezor/tools/README.md
new file mode 100644
index 000000000..91a8fb3f0
--- /dev/null
+++ b/src/device_trezor/trezor/tools/README.md
@@ -0,0 +1,36 @@
+# Trezor
+
+## Messages rebuild
+
+Install `protoc` for your distribution.
+
+- `protobuf-compiler`
+- `libprotobuf-dev`
+- `libprotoc-dev`
+- `python-protobuf`
+
+Python 3 is required. If you don't have python 3 quite an easy way is
+to use [pyenv].
+
+It is also advised to create own python virtual environment so dependencies
+are installed in this project-related virtual environment.
+
+```bash
+python -m venv /
+```
+
+Make sure your python has `protobuf` package installed
+
+```bash
+pip install protobuf
+```
+
+Regenerate messages:
+
+```
+./venv/bin/python3 src/device_trezor/trezor/tools/build_protob.py
+```
+
+The messages regeneration is done also automatically via cmake.
+
+[pyenv]: https://github.com/pyenv/pyenv
diff --git a/src/device_trezor/trezor/tools/build_protob.py b/src/device_trezor/trezor/tools/build_protob.py
new file mode 100644
index 000000000..2611f3296
--- /dev/null
+++ b/src/device_trezor/trezor/tools/build_protob.py
@@ -0,0 +1,38 @@
+#!/usr/bin/env python
+import os
+import subprocess
+import sys
+
+CWD = os.path.dirname(os.path.realpath(__file__))
+ROOT_DIR = os.path.abspath(os.path.join(CWD, "..", "..", "..", ".."))
+TREZOR_COMMON = os.path.join(ROOT_DIR, "external", "trezor-common")
+TREZOR_MESSAGES = os.path.join(CWD, "..", "messages")
+
+# check for existence of the submodule directory
+common_defs = os.path.join(TREZOR_COMMON, "defs")
+if not os.path.exists(common_defs):
+    raise ValueError(
+        "trezor-common submodule seems to be missing.\n"
+        + 'Use "git submodule update --init --recursive" to retrieve it.'
+    )
+
+# regenerate messages
+try:
+    selected = [
+        "messages.proto",
+        "messages-common.proto",
+        "messages-management.proto",
+        "messages-monero.proto",
+    ]
+    proto_srcs = [os.path.join(TREZOR_COMMON, "protob", x) for x in selected]
+    exec_args = [
+        sys.executable,
+        os.path.join(CWD, "pb2cpp.py"),
+        "-o",
+        TREZOR_MESSAGES,
+    ] + proto_srcs
+
+    subprocess.check_call(exec_args)
+
+except Exception as e:
+    raise
diff --git a/src/device_trezor/trezor/tools/pb2cpp.py b/src/device_trezor/trezor/tools/pb2cpp.py
new file mode 100644
index 000000000..eaa8a90ed
--- /dev/null
+++ b/src/device_trezor/trezor/tools/pb2cpp.py
@@ -0,0 +1,186 @@
+#!/usr/bin/env python3
+# Converts Google's protobuf python definitions of TREZOR wire messages
+# to plain-python objects as used in TREZOR Core and python-trezor
+
+import argparse
+import logging
+import os
+import re
+import shutil
+import subprocess
+import sys
+import glob
+import tempfile
+import hashlib
+
+
+AUTO_HEADER = "# Automatically generated by pb2cpp\n"
+
+# Fixing GCC7 compilation error
+UNDEF_STATEMENT = """
+#ifdef minor
+#undef minor
+#endif
+"""
+
+
+def which(pgm):
+    path = os.getenv('PATH')
+    for p in path.split(os.path.pathsep):
+        p = os.path.join(p, pgm)
+        if os.path.exists(p) and os.access(p, os.X_OK):
+            return p
+
+
+PROTOC = which("protoc")
+if not PROTOC:
+    print("protoc command not found")
+    sys.exit(1)
+
+PROTOC_PREFIX = os.path.dirname(os.path.dirname(PROTOC))
+PROTOC_INCLUDE = os.path.join(PROTOC_PREFIX, "include")
+
+
+def namespace_file(fpath, package):
+    """Adds / replaces package name. Simple regex parsing, may use https://github.com/ph4r05/plyprotobuf later"""
+    with open(fpath) as fh:
+        fdata = fh.read()
+
+    re_syntax = re.compile(r"^syntax\s*=")
+    re_package = re.compile(r"^package\s+([^;]+?)\s*;\s*$")
+    lines = fdata.split("\n")
+
+    line_syntax = None
+    line_package = None
+    for idx, line in enumerate(lines):
+        if line_syntax is None and re_syntax.match(line):
+            line_syntax = idx
+        if line_package is None and re_package.match(line):
+            line_package = idx
+
+    if package is None:
+        if line_package is None:
+            return
+        else:
+            lines.pop(line_package)
+
+    else:
+        new_package = "package %s;" % package
+        if line_package is None:
+            lines.insert(line_syntax + 1 if line_syntax is not None else 0, new_package)
+        else:
+            lines[line_package] = new_package
+
+    new_fdat = "\n".join(lines)
+    with open(fpath, "w+") as fh:
+        fh.write(new_fdat)
+    return new_fdat
+
+
+def protoc(files, out_dir, additional_includes=(), package=None, force=False):
+    """Compile code with protoc and return the data."""
+
+    include_dirs = set()
+    include_dirs.add(PROTOC_INCLUDE)
+    include_dirs.update(additional_includes)
+
+    with tempfile.TemporaryDirectory() as tmpdir_protob, tempfile.TemporaryDirectory() as tmpdir_out:
+        include_dirs.add(tmpdir_protob)
+
+        new_files = []
+        for file in files:
+            bname = os.path.basename(file)
+            tmp_file = os.path.join(tmpdir_protob, bname)
+
+            shutil.copy(file, tmp_file)
+            if package is not None:
+                namespace_file(tmp_file, package)
+            new_files.append(tmp_file)
+
+        protoc_includes = ["-I" + dir for dir in include_dirs if dir]
+
+        exec_args = (
+            [
+                PROTOC,
+                "--cpp_out",
+                tmpdir_out,
+            ]
+            + protoc_includes
+            + new_files
+        )
+
+        subprocess.check_call(exec_args)
+
+        # Fixing gcc compilation and clashes with "minor" field name
+        add_undef(tmpdir_out)
+
+        # Scan output dir, check file differences
+        update_message_files(tmpdir_out, out_dir, force)
+
+
+def update_message_files(tmpdir_out, out_dir, force=False):
+    files = glob.glob(os.path.join(tmpdir_out, '*.pb.*'))
+    for fname in files:
+        bname = os.path.basename(fname)
+        dest_file = os.path.join(out_dir, bname)
+        if not force and os.path.exists(dest_file):
+            data = open(fname, 'rb').read()
+            data_hash = hashlib.sha3_256(data).digest()
+            data_dest = open(dest_file, 'rb').read()
+            data_dest_hash = hashlib.sha3_256(data_dest).digest()
+            if data_hash == data_dest_hash:
+                continue
+
+        shutil.copy(fname, dest_file)
+
+
+def add_undef(out_dir):
+    files = glob.glob(os.path.join(out_dir, '*.pb.*'))
+    for fname in files:
+        with open(fname) as fh:
+            lines = fh.readlines()
+
+        idx_insertion = None
+        for idx in range(len(lines)):
+            if '@@protoc_insertion_point(includes)' in lines[idx]:
+                idx_insertion = idx
+                break
+
+        if idx_insertion is None:
+            pass
+
+        lines.insert(idx_insertion + 1, UNDEF_STATEMENT)
+        with open(fname, 'w') as fh:
+            fh.write("".join(lines))
+
+
+def strip_leader(s, prefix):
+    """Remove given prefix from underscored name."""
+    leader = prefix + "_"
+    if s.startswith(leader):
+        return s[len(leader) :]
+    else:
+        return s
+
+
+if __name__ == "__main__":
+    logging.basicConfig(level=logging.DEBUG)
+
+    parser = argparse.ArgumentParser()
+    # fmt: off
+    parser.add_argument("proto", nargs="+", help="Protobuf definition files")
+    parser.add_argument("-o", "--out-dir", help="Directory for generated source code")
+    parser.add_argument("-n", "--namespace", default=None, help="Message namespace")
+    parser.add_argument("-I", "--protoc-include", action="append", help="protoc include path")
+    parser.add_argument("-P", "--protobuf-module", default="protobuf", help="Name of protobuf module")
+    parser.add_argument("-f", "--force", default=False, help="Overwrite existing files")
+    # fmt: on
+    args = parser.parse_args()
+
+    protoc_includes = args.protoc_include or (os.environ.get("PROTOC_INCLUDE"),)
+
+    protoc(
+        args.proto, args.out_dir, protoc_includes, package=args.namespace, force=args.force
+    )
+
+
diff --git a/src/device_trezor/trezor/transport.cpp b/src/device_trezor/trezor/transport.cpp
new file mode 100644
index 000000000..fc86177e1
--- /dev/null
+++ b/src/device_trezor/trezor/transport.cpp
@@ -0,0 +1,651 @@
+// 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 <boost/endian/conversion.hpp>
+#include <boost/asio/io_service.hpp>
+#include <boost/asio/ip/udp.hpp>
+#include <boost/date_time/posix_time/posix_time_types.hpp>
+#include "transport.hpp"
+#include "messages/messages-common.pb.h"
+
+using namespace std;
+using json = rapidjson::Document;
+
+
+namespace hw{
+namespace trezor{
+
+  bool t_serialize(const std::string & in, std::string & out){
+    out = in;
+    return true;
+  }
+
+  bool t_serialize(const json_val & in, std::string & out){
+    rapidjson::StringBuffer sb;
+    rapidjson::Writer<rapidjson::StringBuffer> writer(sb);
+    in.Accept(writer);
+    out = sb.GetString();
+    return true;
+  }
+
+  std::string t_serialize(const json_val & in){
+    std::string ret;
+    t_serialize(in, ret);
+    return ret;
+  }
+
+  bool t_deserialize(const std::string & in, std::string & out){
+    out = in;
+    return true;
+  }
+
+  bool t_deserialize(const std::string & in, json & out){
+    if (out.Parse(in.c_str()).HasParseError()) {
+      throw exc::CommunicationException("JSON parse error");
+    }
+    return true;
+  }
+
+  static std::string json_get_string(const rapidjson::Value & in){
+    return std::string(in.GetString());
+  }
+
+  //
+  // Helpers
+  //
+
+#define PROTO_HEADER_SIZE 6
+
+  static size_t message_size(const google::protobuf::Message &req){
+    return static_cast<size_t>(req.ByteSize());
+  }
+
+  static size_t serialize_message_buffer_size(size_t msg_size) {
+    return PROTO_HEADER_SIZE + msg_size;  // tag 2B + len 4B
+  }
+
+  static void serialize_message_header(void * buff, uint16_t tag, uint32_t len){
+    uint16_t wire_tag = boost::endian::native_to_big(static_cast<uint16_t>(tag));
+    uint32_t wire_len = boost::endian::native_to_big(static_cast<uint32_t>(len));
+    memcpy(buff, (void *) &wire_tag, 2);
+    memcpy((uint8_t*)buff + 2, (void *) &wire_len, 4);
+  }
+
+  static void deserialize_message_header(const void * buff, uint16_t & tag, uint32_t & len){
+    uint16_t wire_tag;
+    uint32_t wire_len;
+    memcpy(&wire_tag, buff, 2);
+    memcpy(&wire_len, (uint8_t*)buff + 2, 4);
+
+    tag = boost::endian::big_to_native(wire_tag);
+    len = boost::endian::big_to_native(wire_len);
+  }
+
+  static void serialize_message(const google::protobuf::Message &req, size_t msg_size, uint8_t * buff, size_t buff_size) {
+    auto msg_wire_num = MessageMapper::get_message_wire_number(req);
+    const auto req_buffer_size = serialize_message_buffer_size(msg_size);
+    if (req_buffer_size > buff_size){
+      throw std::invalid_argument("Buffer too small");
+    }
+
+    serialize_message_header(buff, msg_wire_num, msg_size);
+    if (!req.SerializeToArray(buff + 6, msg_size)){
+      throw exc::EncodingException("Message serialization error");
+    }
+  }
+
+  //
+  // Communication protocol
+  //
+
+#define REPLEN 64
+
+  void ProtocolV1::write(Transport & transport, const google::protobuf::Message & req){
+    const auto msg_size = message_size(req);
+    const auto buff_size = serialize_message_buffer_size(msg_size) + 2;
+
+    std::unique_ptr<uint8_t[]> req_buff(new uint8_t[buff_size]);
+    uint8_t * req_buff_raw = req_buff.get();
+    req_buff_raw[0] = '#';
+    req_buff_raw[1] = '#';
+
+    serialize_message(req, msg_size, req_buff_raw + 2, buff_size - 2);
+
+    size_t offset = 0;
+    uint8_t chunk_buff[REPLEN];
+
+    // Chunk by chunk upload
+    while(offset < buff_size){
+      auto to_copy = std::min((size_t)(buff_size - offset), (size_t)(REPLEN - 1));
+
+      chunk_buff[0] = '?';
+      memcpy(chunk_buff + 1, req_buff_raw + offset, to_copy);
+
+      // Pad with zeros
+      if (to_copy < REPLEN - 1){
+        memset(chunk_buff + 1 + to_copy, 0, REPLEN - 1 - to_copy);
+      }
+
+      transport.write_chunk(chunk_buff, REPLEN);
+      offset += REPLEN - 1;
+    }
+  }
+
+  void ProtocolV1::read(Transport & transport, std::shared_ptr<google::protobuf::Message> & msg, messages::MessageType * msg_type){
+    char chunk[REPLEN];
+
+    // Initial chunk read
+    size_t nread = transport.read_chunk(chunk, REPLEN);
+    if (nread != REPLEN){
+      throw exc::CommunicationException("Read chunk has invalid size");
+    }
+
+    if (strncmp(chunk, "?##", 3) != 0){
+      throw exc::CommunicationException("Malformed chunk");
+    }
+
+    uint16_t tag;
+    uint32_t len;
+    nread -= 3 + 6;
+    deserialize_message_header(chunk + 3, tag, len);
+
+    std::string data_acc(chunk + 3 + 6, nread);
+    data_acc.reserve(len);
+
+    while(nread < len){
+      const size_t cur = transport.read_chunk(chunk, REPLEN);
+      if (chunk[0] != '?'){
+        throw exc::CommunicationException("Chunk malformed");
+      }
+
+      data_acc.append(chunk + 1, cur - 1);
+      nread += cur - 1;
+    }
+
+    if (msg_type){
+      *msg_type = static_cast<messages::MessageType>(tag);
+    }
+
+    if (nread < len){
+      throw exc::CommunicationException("Response incomplete");
+    }
+
+    std::shared_ptr<google::protobuf::Message> msg_wrap(MessageMapper::get_message(tag));
+    if (!msg_wrap->ParseFromArray(data_acc.c_str(), len)){
+      throw exc::CommunicationException("Message could not be parsed");
+    }
+
+    msg = msg_wrap;
+  }
+
+  //
+  // Bridge transport
+  //
+
+  const char * BridgeTransport::PATH_PREFIX = "bridge:";
+
+  std::string BridgeTransport::get_path() const {
+    if (!m_device_path){
+      return "";
+    }
+
+    std::string path(PATH_PREFIX);
+    return path + m_device_path.get();
+  }
+
+  void BridgeTransport::enumerate(t_transport_vect & res) {
+    json bridge_res;
+    std::string req;
+
+    bool req_status = invoke_bridge_http("/enumerate", req, bridge_res, m_http_client);
+    if (!req_status){
+      throw exc::CommunicationException("Bridge enumeration failed");
+    }
+
+    for(rapidjson::Value::ConstValueIterator itr = bridge_res.Begin(); itr != bridge_res.End(); ++itr){
+      auto element = itr->GetObject();
+      auto t = std::make_shared<BridgeTransport>(boost::make_optional(json_get_string(element["path"])));
+      t->m_device_info.emplace();
+      t->m_device_info->CopyFrom(*itr, t->m_device_info->GetAllocator());
+      res.push_back(t);
+    }
+  }
+
+  void BridgeTransport::open() {
+    if (!m_device_path){
+      throw exc::CommunicationException("Coud not open, empty device path");
+    }
+
+    std::string uri = "/acquire/" + m_device_path.get() + "/null";
+    std::string req;
+    json bridge_res;
+    bool req_status = invoke_bridge_http(uri, req, bridge_res, m_http_client);
+    if (!req_status){
+      throw exc::CommunicationException("Failed to acquire device");
+    }
+
+    m_session = boost::make_optional(json_get_string(bridge_res["session"]));
+  }
+
+  void BridgeTransport::close() {
+    if (!m_device_path || !m_session){
+      throw exc::CommunicationException("Device not open");
+    }
+
+    std::string uri = "/release/" + m_session.get();
+    std::string req;
+    json bridge_res;
+    bool req_status = invoke_bridge_http(uri, req, bridge_res, m_http_client);
+    if (!req_status){
+      throw exc::CommunicationException("Failed to release device");
+    }
+
+    m_session = boost::none;
+  }
+
+  void BridgeTransport::write(const google::protobuf::Message &req) {
+    m_response = boost::none;
+
+    const auto msg_size = message_size(req);
+    const auto buff_size = serialize_message_buffer_size(msg_size);
+
+    std::unique_ptr<uint8_t[]> req_buff(new uint8_t[buff_size]);
+    uint8_t * req_buff_raw = req_buff.get();
+
+    serialize_message(req, msg_size, req_buff_raw, buff_size);
+
+    std::string uri = "/call/" + m_session.get();
+    std::string req_hex = epee::to_hex::string(epee::span<const std::uint8_t>(req_buff_raw, buff_size));
+    std::string res_hex;
+
+    bool req_status = invoke_bridge_http(uri, req_hex, res_hex, m_http_client);
+    if (!req_status){
+      throw exc::CommunicationException("Call method failed");
+    }
+
+    m_response = res_hex;
+  }
+
+  void BridgeTransport::read(std::shared_ptr<google::protobuf::Message> & msg, messages::MessageType * msg_type) {
+    if (!m_response){
+      throw exc::CommunicationException("Could not read, no response stored");
+    }
+
+    std::string bin_data;
+    if (!epee::string_tools::parse_hexstr_to_binbuff(m_response.get(), bin_data)){
+      throw exc::CommunicationException("Response is not well hexcoded");
+    }
+
+    uint16_t msg_tag;
+    uint32_t msg_len;
+    deserialize_message_header(bin_data.c_str(), msg_tag, msg_len);
+    if (bin_data.size() != msg_len + 6){
+      throw exc::CommunicationException("Response is not well hexcoded");
+    }
+
+    if (msg_type){
+      *msg_type = static_cast<messages::MessageType>(msg_tag);
+    }
+
+    std::shared_ptr<google::protobuf::Message> msg_wrap(MessageMapper::get_message(msg_tag));
+    if (!msg_wrap->ParseFromArray(bin_data.c_str() + 6, msg_len)){
+      throw exc::EncodingException("Response is not well hexcoded");
+    }
+    msg = msg_wrap;
+  }
+
+  const boost::optional<json> & BridgeTransport::device_info() const {
+    return m_device_info;
+  }
+
+  std::ostream& BridgeTransport::dump(std::ostream& o) const {
+    return o << "BridgeTransport<path=" << (m_device_path ? get_path() : "None")
+             << ", info=" << (m_device_info ? t_serialize(m_device_info.get()) : "None")
+             << ", session=" << (m_session ? m_session.get() : "None")
+             << ">";
+  }
+
+  //
+  // UdpTransport
+  //
+  const char * UdpTransport::PATH_PREFIX = "udp:";
+  const char * UdpTransport::DEFAULT_HOST = "127.0.0.1";
+  const int UdpTransport::DEFAULT_PORT = 21324;
+
+  UdpTransport::UdpTransport(boost::optional<std::string> device_path,
+                             boost::optional<std::shared_ptr<Protocol>> proto) :
+      m_io_service(), m_deadline(m_io_service)
+  {
+    m_device_port = DEFAULT_PORT;
+    if (device_path) {
+      const std::string device_str = device_path.get();
+      auto delim = device_str.find(':');
+      if (delim == std::string::npos) {
+        m_device_host = device_str;
+      } else {
+        m_device_host = device_str.substr(0, delim);
+        m_device_port = std::stoi(device_str.substr(delim + 1));
+      }
+    } else {
+      m_device_host = DEFAULT_HOST;
+    }
+
+    if (m_device_port <= 1024 || m_device_port > 65535){
+      throw std::invalid_argument("Port number invalid");
+    }
+
+    if (m_device_host != "localhost" && m_device_host != DEFAULT_HOST){
+      throw std::invalid_argument("Local endpoint allowed only");
+    }
+
+    m_proto = proto ? proto.get() : std::make_shared<ProtocolV1>();
+  }
+
+  std::string UdpTransport::get_path() const {
+    std::string path(PATH_PREFIX);
+    return path + m_device_host + ":" + std::to_string(m_device_port);
+  }
+
+  void UdpTransport::require_socket(){
+    if (!m_socket){
+      throw exc::NotConnectedException("Socket not connected");
+    }
+  }
+
+  bool UdpTransport::ping(){
+    return ping_int();
+  }
+
+  bool UdpTransport::ping_int(boost::posix_time::time_duration timeout){
+    require_socket();
+    try {
+      std::string req = "PINGPING";
+      char res[8];
+
+      m_socket->send_to(boost::asio::buffer(req.c_str(), req.size()), m_endpoint);
+      receive(res, 8, nullptr, false, timeout);
+
+      return memcmp(res, "PONGPONG", 8) == 0;
+
+    } catch(...){
+      return false;
+    }
+  }
+
+  void UdpTransport::enumerate(t_transport_vect & res) {
+    std::shared_ptr<UdpTransport> t = std::make_shared<UdpTransport>();
+    bool t_works = false;
+
+    try{
+      t->open();
+      t_works = t->ping();
+    } catch(...) {
+
+    }
+    t->close();
+    if (t_works){
+      res.push_back(t);
+    }
+  }
+
+  void UdpTransport::open() {
+    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);
+
+    m_socket.reset(new udp::socket(m_io_service));
+    m_socket->open(udp::v4());
+
+    m_deadline.expires_at(boost::posix_time::pos_infin);
+    check_deadline();
+
+    m_proto->session_begin(*this);
+  }
+
+  void UdpTransport::close() {
+    if (!m_socket){
+      throw exc::CommunicationException("Socket is already closed");
+    }
+
+    m_proto->session_end(*this);
+    m_socket->close();
+    m_socket = nullptr;
+  }
+
+  void UdpTransport::write_chunk(const void * buff, size_t size){
+    require_socket();
+
+    if (size != 64){
+      throw exc::CommunicationException("Invalid chunk size");
+    }
+
+    auto written = m_socket->send_to(boost::asio::buffer(buff, size), m_endpoint);
+    if (size != written){
+      throw exc::CommunicationException("Could not send the whole chunk");
+    }
+  }
+
+  size_t UdpTransport::read_chunk(void * buff, size_t size){
+    require_socket();
+    if (size < 64){
+      throw std::invalid_argument("Buffer too small");
+    }
+
+    ssize_t len;
+    while(true) {
+      try {
+        boost::system::error_code ec;
+        len = receive(buff, size, &ec, true);
+        if (ec == boost::asio::error::operation_aborted) {
+          continue;
+        } else if (ec) {
+          throw exc::CommunicationException(std::string("Comm error: ") + ec.message());
+        }
+
+        if (len != 64) {
+          throw exc::CommunicationException("Invalid chunk size");
+        }
+
+        break;
+
+      } catch(exc::CommunicationException const& e){
+        throw;
+      } catch(std::exception const& e){
+        MWARNING("Error reading chunk, reason: " << e.what());
+        throw exc::CommunicationException(std::string("Chunk read error: ") + std::string(e.what()));
+      }
+    }
+
+    return static_cast<size_t>(len);
+  }
+
+  ssize_t UdpTransport::receive(void * buff, size_t size, boost::system::error_code * error_code, bool no_throw, boost::posix_time::time_duration timeout){
+    boost::system::error_code ec;
+    boost::asio::mutable_buffer buffer = boost::asio::buffer(buff, size);
+
+    require_socket();
+
+    // Set a deadline for the asynchronous operation.
+    m_deadline.expires_from_now(timeout);
+
+    // Set up the variables that receive the result of the asynchronous
+    // operation. The error code is set to would_block to signal that the
+    // operation is incomplete. Asio guarantees that its asynchronous
+    // operations will never fail with would_block, so any other value in
+    // ec indicates completion.
+    ec = boost::asio::error::would_block;
+    std::size_t length = 0;
+
+    // Start the asynchronous operation itself. The handle_receive function
+    // used as a callback will update the ec and length variables.
+    m_socket->async_receive_from(boost::asio::buffer(buffer), m_endpoint,
+                                 boost::bind(&UdpTransport::handle_receive, _1, _2, &ec, &length));
+
+    // Block until the asynchronous operation has completed.
+    do {
+      m_io_service.run_one();
+    }
+    while (ec == boost::asio::error::would_block);
+
+    if (error_code){
+      *error_code = ec;
+    }
+
+    if (no_throw){
+      return length;
+    }
+
+    // Operation result
+    if (ec == boost::asio::error::operation_aborted){
+      throw exc::TimeoutException();
+
+    } else if (ec) {
+      MWARNING("Reading from UDP socket failed: " << ec.message());
+      throw exc::CommunicationException();
+
+    }
+
+    return length;
+  }
+
+  void UdpTransport::write(const google::protobuf::Message &req) {
+    m_proto->write(*this, req);
+  }
+
+  void UdpTransport::read(std::shared_ptr<google::protobuf::Message> & msg, messages::MessageType * msg_type) {
+    m_proto->read(*this, msg, msg_type);
+  }
+
+  void UdpTransport::check_deadline(){
+    if (!m_socket){
+      return;  // no active socket.
+    }
+
+    // Check whether the deadline has passed. We compare the deadline against
+    // the current time since a new asynchronous operation may have moved the
+    // deadline before this actor had a chance to run.
+    if (m_deadline.expires_at() <= boost::asio::deadline_timer::traits_type::now())
+    {
+      // The deadline has passed. The outstanding asynchronous operation needs
+      // to be cancelled so that the blocked receive() function will return.
+      //
+      // Please note that cancel() has portability issues on some versions of
+      // Microsoft Windows, and it may be necessary to use close() instead.
+      // Consult the documentation for cancel() for further information.
+      m_socket->cancel();
+
+      // There is no longer an active deadline. The expiry is set to positive
+      // infinity so that the actor takes no action until a new deadline is set.
+      m_deadline.expires_at(boost::posix_time::pos_infin);
+    }
+
+    // Put the actor back to sleep.
+    m_deadline.async_wait(boost::bind(&UdpTransport::check_deadline, this));
+  }
+
+  void UdpTransport::handle_receive(const boost::system::error_code &ec, std::size_t length,
+                                    boost::system::error_code *out_ec, std::size_t *out_length) {
+    *out_ec = ec;
+    *out_length = length;
+  }
+
+  std::ostream& UdpTransport::dump(std::ostream& o) const {
+    return o << "UdpTransport<path=" << get_path()
+             << ", socket_alive=" << (m_socket ? "true" : "false")
+             << ">";
+  }
+
+  void enumerate(t_transport_vect & res){
+    BridgeTransport bt;
+    bt.enumerate(res);
+
+    hw::trezor::UdpTransport btu;
+    btu.enumerate(res);
+  }
+
+  std::shared_ptr<Transport> transport(const std::string & path){
+    if (boost::starts_with(path, BridgeTransport::PATH_PREFIX)){
+      return std::make_shared<BridgeTransport>(path.substr(strlen(BridgeTransport::PATH_PREFIX)));
+
+    } else if (boost::starts_with(path, UdpTransport::PATH_PREFIX)){
+      return std::make_shared<UdpTransport>(path.substr(strlen(UdpTransport::PATH_PREFIX)));
+
+    } else {
+      throw std::invalid_argument("Unknown Trezor device path: " + path);
+
+    }
+  }
+
+  void throw_failure_exception(const messages::common::Failure * failure) {
+    if (failure == nullptr){
+      throw std::invalid_argument("Failure message cannot be null");
+    }
+
+    boost::optional<std::string> message = failure->has_message() ? boost::make_optional(failure->message()) : boost::none;
+    boost::optional<uint32_t> code = failure->has_code() ? boost::make_optional(static_cast<uint32_t>(failure->code())) : boost::none;
+    if (!code){
+      throw exc::proto::FailureException(code, message);
+    }
+
+    auto ecode = failure->code();
+    if (ecode == messages::common::Failure_FailureType_Failure_UnexpectedMessage){
+      throw exc::proto::UnexpectedMessageException(code, message);
+    } else if (ecode == messages::common::Failure_FailureType_Failure_ActionCancelled){
+      throw exc::proto::CancelledException(code, message);
+    } else if (ecode == messages::common::Failure_FailureType_Failure_PinExpected){
+      throw exc::proto::PinExpectedException(code, message);
+    } else if (ecode == messages::common::Failure_FailureType_Failure_PinInvalid){
+      throw exc::proto::InvalidPinException(code, message);
+    } else if (ecode == messages::common::Failure_FailureType_Failure_NotEnoughFunds){
+      throw exc::proto::NotEnoughFundsException(code, message);
+    } else if (ecode == messages::common::Failure_FailureType_Failure_NotInitialized){
+      throw exc::proto::NotInitializedException(code, message);
+    } else if (ecode == messages::common::Failure_FailureType_Failure_FirmwareError){
+      throw exc::proto::FirmwareErrorException(code, message);
+    } else {
+      throw exc::proto::FailureException(code, message);
+    }
+  }
+
+  std::ostream& operator<<(std::ostream& o, hw::trezor::Transport const& t){
+    return t.dump(o);
+  }
+
+  std::ostream& operator<<(std::ostream& o, std::shared_ptr<hw::trezor::Transport> const& t){
+    if (!t){
+      return o << "None";
+    }
+
+    return t->dump(o);
+  }
+
+}
+}
+
+
diff --git a/src/device_trezor/trezor/transport.hpp b/src/device_trezor/trezor/transport.hpp
new file mode 100644
index 000000000..7b82fd06f
--- /dev/null
+++ b/src/device_trezor/trezor/transport.hpp
@@ -0,0 +1,331 @@
+// 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_TRANSPORT_H
+#define MONERO_TRANSPORT_H
+
+
+#include <boost/asio.hpp>
+#include <boost/asio/deadline_timer.hpp>
+#include <boost/array.hpp>
+#include <boost/utility/string_ref.hpp>
+
+#include <typeinfo>
+#include <type_traits>
+#include "net/http_client.h"
+
+#include "rapidjson/document.h"
+#include "rapidjson/writer.h"
+#include "rapidjson/stringbuffer.h"
+
+#include "exceptions.hpp"
+#include "trezor_defs.hpp"
+#include "messages_map.hpp"
+
+#include "messages/messages.pb.h"
+#include "messages/messages-common.pb.h"
+#include "messages/messages-management.pb.h"
+#include "messages/messages-monero.pb.h"
+
+namespace hw {
+namespace trezor {
+
+  using json = rapidjson::Document;
+  using json_val = rapidjson::Value;
+  namespace http = epee::net_utils::http;
+
+  const std::string DEFAULT_BRIDGE = "127.0.0.1:21325";
+
+  // Base HTTP comm serialization.
+  bool t_serialize(const std::string & in, std::string & out);
+  bool t_serialize(const json_val & in, std::string & out);
+  std::string t_serialize(const json_val & in);
+
+  bool t_deserialize(const std::string & in, std::string & out);
+  bool t_deserialize(const std::string & in, json & out);
+
+  // Flexible json serialization. HTTP client tailored for bridge API
+  template<class t_req, class t_res, class t_transport>
+  bool invoke_bridge_http(const boost::string_ref uri, const t_req & out_struct, t_res & result_struct, t_transport& transport, const boost::string_ref method = "POST", std::chrono::milliseconds timeout = std::chrono::seconds(180))
+  {
+    std::string req_param;
+    t_serialize(out_struct, req_param);
+
+    http::fields_list additional_params;
+    additional_params.push_back(std::make_pair("Origin","https://monero.trezor.io"));
+    additional_params.push_back(std::make_pair("Content-Type","application/json; charset=utf-8"));
+
+    const http::http_response_info* pri = nullptr;
+    if(!transport.invoke(uri, method, req_param, timeout, &pri, std::move(additional_params)))
+    {
+      MERROR("Failed to invoke http request to  " << uri);
+      return false;
+    }
+
+    if(!pri)
+    {
+      MERROR("Failed to invoke http request to  " << uri << ", internal error (null response ptr)");
+      return false;
+    }
+
+    if(pri->m_response_code != 200)
+    {
+      MERROR("Failed to invoke http request to  " << uri << ", wrong response code: " << pri->m_response_code
+             << " Response Body: " << pri->m_body);
+      return false;
+    }
+
+    return t_deserialize(pri->m_body, result_struct);
+  }
+
+  // Forward decl
+  class Transport;
+  class Protocol;
+
+  // Communication protocol
+  class Protocol {
+  public:
+    Protocol() = default;
+    virtual ~Protocol() = default;
+    virtual void session_begin(Transport & transport){ };
+    virtual void session_end(Transport & transport){ };
+    virtual void write(Transport & transport, const google::protobuf::Message & req)= 0;
+    virtual void read(Transport & transport, std::shared_ptr<google::protobuf::Message> & msg, messages::MessageType * msg_type=nullptr)= 0;
+  };
+
+  class ProtocolV1 : public Protocol {
+  public:
+    ProtocolV1() = default;
+    virtual ~ProtocolV1() = default;
+
+    void write(Transport & transport, const google::protobuf::Message & req) override;
+    void read(Transport & transport, std::shared_ptr<google::protobuf::Message> & msg, messages::MessageType * msg_type=nullptr) override;
+  };
+
+
+  // Base transport
+  typedef std::vector<std::shared_ptr<Transport>> t_transport_vect;
+
+  class Transport {
+  public:
+    Transport() = default;
+    virtual ~Transport() = default;
+
+    virtual bool ping() { return false; };
+    virtual std::string get_path() const { return ""; };
+    virtual void enumerate(t_transport_vect & res){};
+    virtual void open(){};
+    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 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<>"; }
+  };
+
+  // Bridge transport
+  class BridgeTransport : public Transport {
+  public:
+    BridgeTransport(
+        boost::optional<std::string> device_path = boost::none,
+        boost::optional<std::string> bridge_host = boost::none):
+        m_device_path(device_path),
+        m_bridge_host(bridge_host ? bridge_host.get() : DEFAULT_BRIDGE),
+        m_response(boost::none),
+        m_session(boost::none),
+        m_device_info(boost::none)
+    {
+      m_http_client.set_server(m_bridge_host, boost::none, false);
+    }
+
+    virtual ~BridgeTransport() = default;
+
+    static const char * PATH_PREFIX;
+
+    std::string get_path() const override;
+    void enumerate(t_transport_vect & res) override;
+
+    void open() override;
+    void close() override;
+
+    void write(const google::protobuf::Message &req) override;
+    void read(std::shared_ptr<google::protobuf::Message> & msg, messages::MessageType * msg_type=nullptr) override;
+
+    const boost::optional<json> & device_info() const;
+    std::ostream& dump(std::ostream& o) const override;
+
+  private:
+    epee::net_utils::http::http_simple_client m_http_client;
+    std::string m_bridge_host;
+    boost::optional<std::string> m_device_path;
+    boost::optional<std::string> m_session;
+    boost::optional<std::string> m_response;
+    boost::optional<json> m_device_info;
+  };
+
+  // UdpTransport transport
+  using boost::asio::ip::udp;
+
+  class UdpTransport : public Transport {
+  public:
+
+    explicit UdpTransport(
+        boost::optional<std::string> device_path=boost::none,
+        boost::optional<std::shared_ptr<Protocol>> proto=boost::none);
+
+    virtual ~UdpTransport() = default;
+
+    static const char * PATH_PREFIX;
+    static const char * DEFAULT_HOST;
+    static const int DEFAULT_PORT;
+
+    bool ping() override;
+    std::string get_path() const override;
+    void enumerate(t_transport_vect & res) override;
+
+    void open() override;
+    void close() override;
+
+    void write(const google::protobuf::Message &req) override;
+    void read(std::shared_ptr<google::protobuf::Message> & msg, messages::MessageType * msg_type=nullptr) override;
+
+    void write_chunk(const void * buff, size_t size) override;
+    size_t read_chunk(void * buff, size_t size) override;
+
+    std::ostream& dump(std::ostream& o) const override;
+
+  private:
+    void require_socket();
+    ssize_t receive(void * buff, size_t size, boost::system::error_code * error_code=nullptr, bool no_throw=false, boost::posix_time::time_duration timeout=boost::posix_time::seconds(10));
+    void check_deadline();
+    static void handle_receive(const boost::system::error_code& ec, std::size_t length,
+                               boost::system::error_code* out_ec, std::size_t* out_length);
+    bool ping_int(boost::posix_time::time_duration timeout=boost::posix_time::milliseconds(1500));
+
+    std::shared_ptr<Protocol> m_proto;
+    std::string m_device_host;
+    int m_device_port;
+
+    std::unique_ptr<udp::socket> m_socket;
+    boost::asio::io_service m_io_service;
+    boost::asio::deadline_timer m_deadline;
+    udp::endpoint m_endpoint;
+  };
+
+  //
+  // General helpers
+  //
+
+  /**
+   * Enumerates all transports
+   */
+  void enumerate(t_transport_vect & res);
+
+  /**
+   * Transforms path to the transport
+   */
+  std::shared_ptr<Transport> transport(const std::string & path);
+
+  /**
+   * Transforms path to the particular transport
+   */
+  template<class t_transport>
+  std::shared_ptr<t_transport> transport_typed(const std::string & path){
+    auto t = transport(path);
+    if (!t){
+      return nullptr;
+    }
+
+    return std::dynamic_pointer_cast<t_transport>(t);
+  }
+
+  // Exception carries unexpected message being received
+  namespace exc {
+    class UnexpectedMessageException: public ProtocolException {
+    protected:
+      hw::trezor::messages::MessageType recvType;
+      std::shared_ptr<google::protobuf::Message> recvMsg;
+
+    public:
+      using ProtocolException::ProtocolException;
+      UnexpectedMessageException(): ProtocolException("Trezor returned unexpected message") {};
+      UnexpectedMessageException(hw::trezor::messages::MessageType recvType,
+                                 const std::shared_ptr<google::protobuf::Message> & recvMsg)
+          : recvType(recvType), recvMsg(recvMsg) {
+        reason = std::string("Trezor returned unexpected message: ") + std::to_string(recvType);
+      }
+    };
+  }
+
+  /**
+   * Throws corresponding failure exception.
+   */
+  [[ noreturn ]] void throw_failure_exception(const messages::common::Failure * failure);
+
+  /**
+   * Simple wrapper for write-read message exchange with expected message response type.
+   *
+   * @throws UnexpectedMessageException if the response message type is different than expected.
+   * Exception contains message type and the message itself.
+   */
+  template<class t_message>
+  std::shared_ptr<t_message>
+      exchange_message(Transport & transport, const google::protobuf::Message & req,
+                       boost::optional<messages::MessageType> resp_type = boost::none)
+  {
+    // Require strictly protocol buffers response in the template.
+    BOOST_STATIC_ASSERT(boost::is_base_of<google::protobuf::Message, t_message>::value);
+
+    // Write the request
+    transport.write(req);
+
+    // Read the response
+    std::shared_ptr<google::protobuf::Message> msg_resp;
+    hw::trezor::messages::MessageType msg_resp_type;
+    transport.read(msg_resp, &msg_resp_type);
+
+    // Determine type of expected message response
+    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);
+    }
+  }
+
+  std::ostream& operator<<(std::ostream& o, hw::trezor::Transport const& t);
+  std::ostream& operator<<(std::ostream& o, std::shared_ptr<hw::trezor::Transport> const& t);
+}}
+
+
+#endif //MONERO_TRANSPORT_H
diff --git a/src/device_trezor/trezor/trezor_defs.hpp b/src/device_trezor/trezor/trezor_defs.hpp
new file mode 100644
index 000000000..951a8f802
--- /dev/null
+++ b/src/device_trezor/trezor/trezor_defs.hpp
@@ -0,0 +1,48 @@
+// 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.
+//
+
+#if defined(HAVE_PROTOBUF) && !defined(WITHOUT_TREZOR)
+  #define WITH_DEVICE_TREZOR 1
+#else
+  #define WITH_DEVICE_TREZOR 0
+#endif
+
+#ifndef WITH_DEVICE_TREZOR_LITE
+#define WITH_DEVICE_TREZOR_LITE 0
+#endif
+
+// Avoids protobuf undefined macro warning
+#ifndef PROTOBUF_INLINE_NOT_IN_HEADERS
+#define PROTOBUF_INLINE_NOT_IN_HEADERS 0
+#endif
+
+// Fixes gcc7 problem with minor macro defined clashing with minor() field.
+#ifdef minor
+#undef minor
+#endif