text: // Parts are Copyright (c) 2019, The Dinastycoin team
  //
  // 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 "version.h"
  #include "protocol.hpp"
  #include <unordered_map>
  #include <set>
  #include <utility>
  #include <boost/endian/conversion.hpp>
  #include <common/apply_permutation.h>
  #include <common/json_util.h>
  #include <crypto/hmac-keccak.h>
  #include <ringct/rctSigs.h>
  #include <ringct/bulletproofs.h>
  #include "cryptonote_config.h"
  #include <sodium.h>
  #include <sodium/crypto_verify_32.h>
  #include <sodium/crypto_aead_chacha20poly1305.h>
  
  #define GET_FIELD_STRING(name, type, jtype) field_##name = std::string(json[#name].GetString(), json[#name].GetStringLength())
  #define GET_FIELD_OTHER(name, type, jtype) field_##name = static_cast<type>(json[#name].Get##jtype())
  
  #define GET_STRING_FROM_JSON(json, name, type, mandatory, def) \
    GET_FIELD_FROM_JSON_EX(json, name, type, String, mandatory, def, GET_FIELD_STRING)
  
  #define GET_FIELD_FROM_JSON(json, name, type, jtype, mandatory, def) \
    GET_FIELD_FROM_JSON_EX(json, name, type, jtype, mandatory, def, GET_FIELD_OTHER)
  
  #define GET_FIELD_FROM_JSON_EX(json, name, type, jtype, mandatory, def, VAL) \
    type field_##name = static_cast<type>(def);                        \
    bool field_##name##_found = false;                                 \
    (void)field_##name##_found;                                        \
    do if (json.HasMember(#name))                                      \
    {                                                                  \
      if (json[#name].Is##jtype())                                     \
      {                                                                \
        VAL(name, type, jtype);                                        \
        field_##name##_found = true;                                   \
      }                                                                \
      else                                                             \
      {                                                                \
        throw std::invalid_argument("Field " #name " found in JSON, but not " #jtype); \
      }                                                                \
    }                                                                  \
    else if (mandatory)                                                \
    {                                                                  \
      throw std::invalid_argument("Field " #name " not found in JSON");\
    } while(0)
  
  
  namespace hw{
  namespace trezor{
  namespace protocol{
  
    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, size_t *plaintext_len){
      CHECK_AND_ASSERT_THROW_MES(length >= TAG_SIZE, "Ciphertext length too small");
      CHECK_AND_ASSERT_THROW_MES(!plaintext_len || *plaintext_len >= (length - TAG_SIZE), "Plaintext length too small");
  
      unsigned long long int res_len = plaintext_len ? *plaintext_len : length;
      auto r = crypto_aead_chacha20poly1305_ietf_decrypt(
          reinterpret_cast<unsigned char *>(plaintext), &res_len, nullptr,
          static_cast<const unsigned char *>(ciphertext), length, nullptr, 0, iv, key);
  
      if (r != 0){
        throw exc::Poly1305TagInvalid();
      }
  
      if (plaintext_len){
        *plaintext_len = (size_t) res_len;
      }
    }
  
  }
  }
  
  
  // Cold Key image sync
  namespace ki {
  
    bool key_image_data(wallet_shim * wallet,
                        const std::vector<tools::wallet2::transfer_details> & transfers,
                        std::vector<DinastycoinTransferDetails> & 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 DinastycoinTransferDetails & 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<DinastycoinTransferDetails> & mtds,
                             const std::vector<tools::wallet2::transfer_details> & transfers,
                             std::shared_ptr<messages::dinastycoin::DinastycoinKeyImageExportInitRequest> & req)
    {
      req = std::make_shared<messages::dinastycoin::DinastycoinKeyImageExportInitRequest>();
  
      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::dinastycoin::DinastycoinKeyImageExportInitRequest>();
      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);
        }
      }
    }
  
    void live_refresh_ack(const ::crypto::secret_key & view_key_priv,
                          const ::crypto::public_key& out_key,
                          const std::shared_ptr<messages::dinastycoin::DinastycoinLiveRefreshStepAck> & ack,
                          ::cryptonote::keypair& in_ephemeral,
                          ::crypto::key_image& ki)
    {
      std::string str_out_key(out_key.data, sizeof(out_key.data));
      auto enc_key = protocol::tx::compute_enc_key(view_key_priv, str_out_key, ack->salt());
  
      const size_t len_ciphertext = ack->key_image().size();  // IV || keys
      CHECK_AND_ASSERT_THROW_MES(len_ciphertext > crypto::chacha::IV_SIZE + crypto::chacha::TAG_SIZE, "Invalid size");
  
      size_t ki_len = len_ciphertext - crypto::chacha::IV_SIZE - crypto::chacha::TAG_SIZE;
      std::unique_ptr<uint8_t[]> plaintext(new uint8_t[ki_len]);
      uint8_t * buff = plaintext.get();
  
      protocol::crypto::chacha::decrypt(
          ack->key_image().data() + crypto::chacha::IV_SIZE,
          len_ciphertext - crypto::chacha::IV_SIZE,
          reinterpret_cast<const uint8_t *>(enc_key.data),
          reinterpret_cast<const uint8_t *>(ack->key_image().data()),
          reinterpret_cast<char *>(buff), &ki_len);
  
      CHECK_AND_ASSERT_THROW_MES(ki_len == 3*32, "Invalid size");
      ::crypto::signature sig{};
      memcpy(ki.data, buff, 32);
      memcpy(sig.c.data, buff + 32, 32);
      memcpy(sig.r.data, buff + 64, 32);
      in_ephemeral.pub = out_key;
      in_ephemeral.sec = ::crypto::null_skey;
  
      // Verification
      std::vector<const ::crypto::public_key*> pkeys;
      pkeys.push_back(&out_key);
  
      CHECK_AND_ASSERT_THROW_MES(rct::scalarmultKey(rct::ki2rct(ki), rct::curveOrder()) == rct::identity(),
                                 "Key image out of validity domain: key image " << epee::string_tools::pod_to_hex(ki));
  
      CHECK_AND_ASSERT_THROW_MES(::crypto::check_ring_signature((const ::crypto::hash&)ki, ki, pkeys, &sig),
                                 "Signature failed for key image " << epee::string_tools::pod_to_hex(ki)
                                                                   << ", signature " + epee::string_tools::pod_to_hex(sig)
                                                                   << ", pubkey " + epee::string_tools::pod_to_hex(*pkeys[0]));
    }
  }
  
  // Cold transaction signing
  namespace tx {
  
    void translate_address(DinastycoinAccountPublicAddress * 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(DinastycoinTransactionDestinationEntry * dst, const cryptonote::tx_destination_entry * src){
      dst->set_amount(src->amount);
      dst->set_is_subaddress(src->is_subaddress);
      dst->set_is_integrated(src->is_integrated);
      dst->set_original(src->original);
      translate_address(dst->mutable_addr(), &(src->addr));
    }
  
    void translate_src_entry(DinastycoinTransactionSourceEntry * 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(DinastycoinMultisigKLRki * 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(DinastycoinRctKey * 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 DinastycoinAccountPublicAddress * 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);
    }
  
    ::crypto::secret_key compute_enc_key(const ::crypto::secret_key & private_view_key, const std::string & aux, const std::string & salt)
    {
      uint8_t hash[32];
      KECCAK_CTX ctx;
      ::crypto::secret_key res;
  
      keccak_init(&ctx);
      keccak_update(&ctx, (const uint8_t *) private_view_key.data, sizeof(private_view_key.data));
      if (!aux.empty()){
        keccak_update(&ctx, (const uint8_t *) aux.data(), aux.size());
      }
      keccak_finish(&ctx, hash);
      keccak(hash, sizeof(hash), hash, sizeof(hash));
  
      hmac_keccak_hash(hash, (const uint8_t *) salt.data(), salt.size(), hash, sizeof(hash));
      memcpy(res.data, hash, sizeof(hash));
      memwipe(hash, sizeof(hash));
      return res;
    }
  
    TData::TData() {
      rsig_type = 0;
      bp_version = 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;
      m_client_version = 1;
    }
  
    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(const rct::RCTConfig &rct_config, size_t num_outputs){
      if (rct_config.range_proof_type == rct::RangeProofBorromean){
        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::dinastycoin::DinastycoinTransactionInitRequest> 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;
      m_client_version = (m_aux_data->client_version ? m_aux_data->client_version.get() : 1);
  
      tsx_data.set_version(1);
      tsx_data.set_client_version(client_version());
      tsx_data.set_unlock_time(tx.unlock_time);
      tsx_data.set_num_inputs(static_cast<google::protobuf::uint32>(tx.sources.size()));
      tsx_data.set_mixin(static_cast<google::protobuf::uint32>(tx.sources[0].outputs.size() - 1));
      tsx_data.set_account(tx.subaddr_account);
      tsx_data.set_dinastycoin_version(std::string(DINASTYCOIN_VERSION) + "|" + DINASTYCOIN_VERSION_TAG);
      tsx_data.set_hard_fork(m_aux_data->hard_fork ? m_aux_data->hard_fork.get() : 0);
      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.rct_config, tx.splitted_dsts.size());
      rsig_data->set_rsig_type(m_ct.rsig_type);
      if (tx.rct_config.range_proof_type != rct::RangeProofBorromean){
        m_ct.bp_version = (m_aux_data->bp_version ? m_aux_data->bp_version.get() : 1);
        rsig_data->set_bp_version((uint32_t) m_ct.bp_version);
      }
  
      generate_rsig_batch_sizes(m_ct.grouping_vct, m_ct.rsig_type, tx.splitted_dsts.size());
      assign_to_repeatable(rsig_data->mutable_grouping(), m_ct.grouping_vct.begin(), m_ct.grouping_vct.end());
  
      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::dinastycoin::DinastycoinTransactionInitRequest>();
      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::dinastycoin::DinastycoinTransactionInitAck> ack){
      if (ack->has_rsig_data()){
        m_ct.rsig_param = std::make_shared<DinastycoinRsigData>(ack->rsig_data());
      }
  
      assign_from_repeatable(&(m_ct.tx_out_entr_hmacs), ack->hmacs().begin(), ack->hmacs().end());
    }
  
    std::shared_ptr<messages::dinastycoin::DinastycoinTransactionSetInputRequest> 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::dinastycoin::DinastycoinTransactionSetInputRequest>();
      translate_src_entry(res->mutable_src_entr(), &(cur_tx().sources[idx]));
      return res;
    }
  
    void Signer::step_set_input_ack(std::shared_ptr<const messages::dinastycoin::DinastycoinTransactionSetInputAck> 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::dinastycoin::DinastycoinTransactionInputsPermutationRequest> Signer::step_permutation(){
      sort_ki();
  
      auto res = std::make_shared<messages::dinastycoin::DinastycoinTransactionInputsPermutationRequest>();
      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::dinastycoin::DinastycoinTransactionInputsPermutationAck> ack){
  
    }
  
    std::shared_ptr<messages::dinastycoin::DinastycoinTransactionInputViniRequest> Signer::step_set_vini_input(size_t 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");
  
      m_ct.cur_input_idx = idx;
      auto tx = m_ct.tx_data;
      auto res = std::make_shared<messages::dinastycoin::DinastycoinTransactionInputViniRequest>();
      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 (client_version() == 0) {
        CHECK_AND_ASSERT_THROW_MES(idx < m_ct.pseudo_outs.size(), "Invalid transaction index");
        CHECK_AND_ASSERT_THROW_MES(idx < m_ct.pseudo_outs_hmac.size(), "Invalid transaction index");
        res->set_pseudo_out(m_ct.pseudo_outs[idx]);
        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::dinastycoin::DinastycoinTransactionInputViniAck> ack){
  
    }
  
    std::shared_ptr<messages::dinastycoin::DinastycoinTransactionAllInputsSetRequest> Signer::step_all_inputs_set(){
      return std::make_shared<messages::dinastycoin::DinastycoinTransactionAllInputsSetRequest>();
    }
  
    void Signer::step_all_inputs_set_ack(std::shared_ptr<const messages::dinastycoin::DinastycoinTransactionAllInputsSetAck> ack){
      if (client_version() > 0 || !is_offloading()){
        return;
      }
  
      // 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::dinastycoin::DinastycoinTransactionSetOutputRequest> Signer::step_set_output(size_t idx){
      CHECK_AND_ASSERT_THROW_MES(idx < m_ct.tx_data.splitted_dsts.size(), "Invalid transaction index");
      CHECK_AND_ASSERT_THROW_MES(idx < m_ct.tx_out_entr_hmacs.size(), "Invalid transaction index");
      CHECK_AND_ASSERT_THROW_MES(is_req_bulletproof(), "Borromean rsig not supported");
  
      m_ct.cur_output_idx = idx;
      m_ct.cur_output_in_batch_idx += 1;   // assumes sequential call to step_set_output()
  
      auto res = std::make_shared<messages::dinastycoin::DinastycoinTransactionSetOutputRequest>();
      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
      // ClientV0 sends offloaded BP with the last message in the batch.
      // ClientV1 needs additional message after the last message in the batch as BP uses deterministic masks.
      if (client_version() == 0 && is_offloading() && should_compute_bp_now()) {
        auto rsig_data = res->mutable_rsig_data();
        compute_bproof(*rsig_data);
      }
  
      return res;
    }
  
    void Signer::step_set_output_ack(std::shared_ptr<const messages::dinastycoin::DinastycoinTransactionSetOutputAck> ack){
      cryptonote::tx_out tx_out;
      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();
        }
  
        if (client_version() >= 1 && rsig_data.has_mask()){
          rct::key cmask{};
          string_to_key(cmask, rsig_data.mask());
          m_ct.rsig_gamma.emplace_back(cmask);
        }
      }
  
      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 (m_ct.bp_version <= 1) {
        if (!cn_deserialize(ack->ecdh_info(), ecdh)){
          throw exc::ProtocolException("Cannot deserialize ecdhtuple");
        }
      } else {
        CHECK_AND_ASSERT_THROW_MES(8 == ack->ecdh_info().size(), "Invalid ECDH.amount size");
        memcpy(ecdh.amount.bytes, ack->ecdh_info().data(), 8);
      }
  
      if (has_rsig && is_req_bulletproof() && !cn_deserialize(rsig_buff, bproof)){
        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);
  
      // ClientV0, if no rsig was generated on Trezor, do not continue.
      // ClientV1+ generates BP after all masks in the current batch are generated
      if (!has_rsig || (client_version() >= 1 && is_offloading())){
        return;
      }
  
      process_bproof(bproof);
      m_ct.cur_batch_idx += 1;
      m_ct.cur_output_in_batch_idx = 0;
    }
  
    bool Signer::should_compute_bp_now() const {
      CHECK_AND_ASSERT_THROW_MES(m_ct.cur_batch_idx < m_ct.grouping_vct.size(), "Invalid batch index");
      return m_ct.grouping_vct[m_ct.cur_batch_idx] <= m_ct.cur_output_in_batch_idx;
    }
  
    void Signer::compute_bproof(messages::dinastycoin::DinastycoinTransactionRsigData & rsig_data){
      auto batch_size = m_ct.grouping_vct[m_ct.cur_batch_idx];
      std::vector<uint64_t> amounts;
      rct::keyV masks;
      CHECK_AND_ASSERT_THROW_MES(m_ct.cur_output_idx + 1 >= batch_size, "Invalid index for batching");
  
      for(size_t i = 0; i < batch_size; ++i){
        const size_t bidx = 1 + m_ct.cur_output_idx - batch_size + i;
        CHECK_AND_ASSERT_THROW_MES(bidx < m_ct.tx_data.splitted_dsts.size(), "Invalid gamma index");
        CHECK_AND_ASSERT_THROW_MES(bidx < m_ct.rsig_gamma.size(), "Invalid gamma index");
  
        amounts.push_back(m_ct.tx_data.splitted_dsts[bidx].amount);
        masks.push_back(m_ct.rsig_gamma[bidx]);
      }
  
      auto bp = bulletproof_PROVE(amounts, masks);
      auto serRsig = cn_serialize(bp);
      m_ct.tx_out_rsigs.emplace_back(bp);
      rsig_data.set_rsig(serRsig);
    }
  
    void Signer::process_bproof(rct::Bulletproof & bproof){
      CHECK_AND_ASSERT_THROW_MES(m_ct.cur_batch_idx < m_ct.grouping_vct.size(), "Invalid batch index");
      auto batch_size = m_ct.grouping_vct[m_ct.cur_batch_idx];
      for (size_t i = 0; i < batch_size; ++i){
        const size_t bidx = 1 + m_ct.cur_output_idx - batch_size + i;
        CHECK_AND_ASSERT_THROW_MES(bidx < m_ct.tx_out_pk.size(), "Invalid out index");
  
        rct::key commitment = m_ct.tx_out_pk[bidx].mask;
        commitment = rct::scalarmultKey(commitment, rct::INV_EIGHT);
        bproof.V.push_back(commitment);
      }
  
      m_ct.tx_out_rsigs.emplace_back(bproof);
      if (!rct::bulletproof_VERIFY(boost::get<rct::Bulletproof>(m_ct.tx_out_rsigs.back()))) {
        throw exc::ProtocolException("Returned range signature is invalid");
      }
    }
  
    std::shared_ptr<messages::dinastycoin::DinastycoinTransactionSetOutputRequest> Signer::step_rsig(size_t idx){
      if (client_version() == 0 || !is_offloading() || !should_compute_bp_now()){
        return nullptr;
      }
  
      auto res = std::make_shared<messages::dinastycoin::DinastycoinTransactionSetOutputRequest>();
      auto & cur_dst = m_ct.tx_data.splitted_dsts[idx];
      translate_dst_entry(res->mutable_dst_entr(), &cur_dst);
      res->set_dst_entr_hmac(m_ct.tx_out_entr_hmacs[idx]);
  
      compute_bproof(*(res->mutable_rsig_data()));
      res->set_is_offloaded_bp(true);
      return res;
    }
  
    void Signer::step_set_rsig_ack(std::shared_ptr<const messages::dinastycoin::DinastycoinTransactionSetOutputAck> ack){
      m_ct.cur_batch_idx += 1;
      m_ct.cur_output_in_batch_idx = 0;
    }
  
    std::shared_ptr<messages::dinastycoin::DinastycoinTransactionAllOutSetRequest> Signer::step_all_outs_set(){
      return std::make_shared<messages::dinastycoin::DinastycoinTransactionAllOutSetRequest>();
    }
  
    void Signer::step_all_outs_set_ack(std::shared_ptr<const messages::dinastycoin::DinastycoinTransactionAllOutSetAck> 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::dinastycoin::DinastycoinTransactionSignInputRequest> 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::dinastycoin::DinastycoinTransactionSignInputRequest>();
      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]);
  
      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::dinastycoin::DinastycoinTransactionSignInputAck> ack){
      rct::mgSig mg;
      if (!cn_deserialize(ack->signature(), mg)){
        throw exc::ProtocolException("Cannot deserialize mg[i]");
      }
  
      // Sync updated pseudo_outputs, client_version>=1, HF10+
      if (client_version() >= 1 && ack->has_pseudo_out()){
        CHECK_AND_ASSERT_THROW_MES(m_ct.cur_input_idx < m_ct.pseudo_outs.size(), "Invalid pseudo-out index");
        m_ct.pseudo_outs[m_ct.cur_input_idx] = ack->pseudo_out();
        if (is_bulletproof()){
          CHECK_AND_ASSERT_THROW_MES(m_ct.cur_input_idx < m_ct.rv->p.pseudoOuts.size(), "Invalid pseudo-out index");
          string_to_key(m_ct.rv->p.pseudoOuts[m_ct.cur_input_idx], ack->pseudo_out());
        } else {
          CHECK_AND_ASSERT_THROW_MES(m_ct.cur_input_idx < m_ct.rv->pseudoOuts.size(), "Invalid pseudo-out index");
          string_to_key(m_ct.rv->pseudoOuts[m_ct.cur_input_idx], ack->pseudo_out());
        }
      }
  
      m_ct.rv->p.MGs.push_back(mg);
    }
  
    std::shared_ptr<messages::dinastycoin::DinastycoinTransactionFinalRequest> Signer::step_final(){
      m_ct.tx.rct_signatures = *(m_ct.rv);
      return std::make_shared<messages::dinastycoin::DinastycoinTransactionFinalRequest>();
    }
  
    void Signer::step_final_ack(std::shared_ptr<const messages::dinastycoin::DinastycoinTransactionFinalAck> ack){
      if (m_multisig){
        auto & cout_key = ack->cout_key();
        for(auto & cur : m_ct.couts){
          if (cur.size() != crypto::chacha::IV_SIZE + 32){
            throw std::invalid_argument("Encrypted cout has invalid length");
          }
  
          char buff[32];
          auto data = cur.data();
  
          crypto::chacha::decrypt(data + crypto::chacha::IV_SIZE, 32, reinterpret_cast<const uint8_t *>(cout_key.data()), reinterpret_cast<const uint8_t *>(data), buff);
          m_ct.couts_dec.emplace_back(buff, 32);
        }
      }
  
      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.tx_prefix_hash.c_str(), m_ct.tx_prefix_hash.size());
      json.AddMember("tx_prefix_hash", 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();
    }
  
    void load_tx_key_data(hw::device_cold::tx_key_data_t & res, const std::string & data)
    {
      rapidjson::Document json;
  
      // The contents should be JSON if the wallet follows the new format.
      if (json.Parse(data.c_str()).HasParseError())
      {
        throw std::invalid_argument("Data parsing error");
      }
      else if(!json.IsObject())
      {
        throw std::invalid_argument("Data parsing error - not an object");
      }
  
      GET_FIELD_FROM_JSON(json, version, int, Int, true, -1);
      GET_STRING_FROM_JSON(json, salt1, std::string, true, std::string());
      GET_STRING_FROM_JSON(json, salt2, std::string, true, std::string());
      GET_STRING_FROM_JSON(json, enc_keys, std::string, true, std::string());
      GET_STRING_FROM_JSON(json, tx_prefix_hash, std::string, false, std::string());
  
      if (field_version != 1)
      {
        throw std::invalid_argument("Unknown version");
      }
  
      res.salt1 = field_salt1;
      res.salt2 = field_salt2;
      res.tx_enc_keys = field_enc_keys;
      res.tx_prefix_hash = field_tx_prefix_hash;
    }
  
    std::shared_ptr<messages::dinastycoin::DinastycoinGetTxKeyRequest> get_tx_key(
        const hw::device_cold::tx_key_data_t & tx_data)
    {
      auto req = std::make_shared<messages::dinastycoin::DinastycoinGetTxKeyRequest>();
      req->set_salt1(tx_data.salt1);
      req->set_salt2(tx_data.salt2);
      req->set_tx_enc_keys(tx_data.tx_enc_keys);
      req->set_tx_prefix_hash(tx_data.tx_prefix_hash);
      req->set_reason(0);
  
      return req;
    }
  
    void get_tx_key_ack(
        std::vector<::crypto::secret_key> & tx_keys,
        const std::string & tx_prefix_hash,
        const ::crypto::secret_key & view_key_priv,
        std::shared_ptr<const messages::dinastycoin::DinastycoinGetTxKeyAck> ack
    )
    {
      auto enc_key = protocol::tx::compute_enc_key(view_key_priv, tx_prefix_hash, ack->salt());
      auto & encrypted_keys = ack->has_tx_derivations() ? ack->tx_derivations() : ack->tx_keys();
  
      const size_t len_ciphertext = encrypted_keys.size();  // IV || keys || TAG
      CHECK_AND_ASSERT_THROW_MES(len_ciphertext > crypto::chacha::IV_SIZE + crypto::chacha::TAG_SIZE, "Invalid size");
  
      size_t keys_len = len_ciphertext - crypto::chacha::IV_SIZE - crypto::chacha::TAG_SIZE;
      std::unique_ptr<uint8_t[]> plaintext(new uint8_t[keys_len]);
  
      protocol::crypto::chacha::decrypt(
          encrypted_keys.data() + crypto::chacha::IV_SIZE,
          len_ciphertext - crypto::chacha::IV_SIZE,
          reinterpret_cast<const uint8_t *>(enc_key.data),
          reinterpret_cast<const uint8_t *>(encrypted_keys.data()),
          reinterpret_cast<char *>(plaintext.get()), &keys_len);
  
      CHECK_AND_ASSERT_THROW_MES(keys_len % 32 == 0, "Invalid size");
      tx_keys.resize(keys_len / 32);
  
      for(unsigned i = 0; i < keys_len / 32; ++i)
      {
        memcpy(tx_keys[i].data, plaintext.get() + 32 * i, 32);
      }
      memwipe(plaintext.get(), keys_len);
    }
  
  }
  }
  }
  }
  