trezor: adapt to new passphrase mechanism

- choice where to enter passphrase is now made on the host
- use wipeable string in the comm stack
- wipe passphrase memory
- protocol optimizations, prepare for new firmware version
- minor fixes and improvements
- tests fixes, HF12 support

6 files changed, 224 insertions, 124 deletions

diff --git a/src/device_trezor/trezor/debug_link.cpp b/src/device_trezor/trezor/debug_link.cpp
index c7ee59afe..102d1f966 100644
--- a/src/device_trezor/trezor/debug_link.cpp
+++ b/src/device_trezor/trezor/debug_link.cpp
@@ -71,9 +71,9 @@ namespace trezor{
     call(decision, boost::none, true);
   }
 
-  void DebugLink::input_swipe(bool swipe){
+  void DebugLink::input_swipe(messages::debug::DebugLinkDecision_DebugSwipeDirection direction){
     messages::debug::DebugLinkDecision decision;
-    decision.set_up_down(swipe);
+    decision.set_swipe(direction);
     call(decision, boost::none, true);
   }
 
diff --git a/src/device_trezor/trezor/debug_link.hpp b/src/device_trezor/trezor/debug_link.hpp
index adf5f1d8f..a5f05ea94 100644
--- a/src/device_trezor/trezor/debug_link.hpp
+++ b/src/device_trezor/trezor/debug_link.hpp
@@ -49,7 +49,7 @@ namespace trezor {
     std::shared_ptr<messages::debug::DebugLinkState> state();
     void input_word(const std::string & word);
     void input_button(bool button);
-    void input_swipe(bool swipe);
+    void input_swipe(messages::debug::DebugLinkDecision_DebugSwipeDirection direction);
     void press_yes() { input_button(true); }
     void press_no() { input_button(false); }
     void stop();
diff --git a/src/device_trezor/trezor/protocol.cpp b/src/device_trezor/trezor/protocol.cpp
index 61e51be14..2a7783497 100644
--- a/src/device_trezor/trezor/protocol.cpp
+++ b/src/device_trezor/trezor/protocol.cpp
@@ -145,7 +145,8 @@ namespace ki {
 
   bool key_image_data(wallet_shim * wallet,
                       const std::vector<tools::wallet2::transfer_details> & transfers,
-                      std::vector<MoneroTransferDetails> & res)
+                      std::vector<MoneroTransferDetails> & res,
+                      bool need_all_additionals)
   {
     for(auto & td : transfers){
       ::crypto::public_key tx_pub_key = wallet->get_tx_pub_key_from_received_outs(td);
@@ -157,8 +158,14 @@ namespace ki {
       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));
+      cres.set_sub_addr_major(td.m_subaddr_index.major);
+      cres.set_sub_addr_minor(td.m_subaddr_index.minor);
+      if (need_all_additionals) {
+        for (auto &aux : additional_tx_pub_keys) {
+          cres.add_additional_tx_pub_keys(key_to_string(aux));
+        }
+      } else if (!additional_tx_pub_keys.empty() && additional_tx_pub_keys.size() > td.m_internal_output_index) {
+        cres.add_additional_tx_pub_keys(key_to_string(additional_tx_pub_keys[td.m_internal_output_index]));
       }
     }
 
@@ -188,7 +195,8 @@ namespace ki {
 
   void generate_commitment(std::vector<MoneroTransferDetails> & mtds,
                            const std::vector<tools::wallet2::transfer_details> & transfers,
-                           std::shared_ptr<messages::monero::MoneroKeyImageExportInitRequest> & req)
+                           std::shared_ptr<messages::monero::MoneroKeyImageExportInitRequest> & req,
+                           bool need_subaddr_indices)
   {
     req = std::make_shared<messages::monero::MoneroKeyImageExportInitRequest>();
 
@@ -213,11 +221,13 @@ namespace ki {
       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);
+    if (need_subaddr_indices) {
+      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);
+        }
       }
     }
   }
@@ -283,26 +293,6 @@ namespace tx {
     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));
@@ -369,6 +359,31 @@ namespace tx {
     return res;
   }
 
+  std::string compute_sealing_key(const std::string & master_key, size_t idx, bool is_iv)
+  {
+    // master-key-32B || domain-sep-12B || index-4B
+    uint8_t hash[32] = {0};
+    KECCAK_CTX ctx;
+    std::string sep = is_iv ? "sig-iv" : "sig-key";
+    std::string idx_data = tools::get_varint_data(idx);
+    if (idx_data.size() > 4){
+      throw std::invalid_argument("index is too big");
+    }
+
+    keccak_init(&ctx);
+    keccak_update(&ctx, (const uint8_t *) master_key.data(), master_key.size());
+    keccak_update(&ctx, (const uint8_t *) sep.data(), sep.size());
+    keccak_update(&ctx, hash, 12 - sep.size());
+    keccak_update(&ctx, (const uint8_t *) idx_data.data(), idx_data.size());
+    if (idx_data.size() < 4) {
+      keccak_update(&ctx, hash, 4 - idx_data.size());
+    }
+
+    keccak_finish(&ctx, hash);
+    keccak(hash, sizeof(hash), hash, sizeof(hash));
+    return std::string((const char*) hash, 32);
+  }
+
   TData::TData() {
     rsig_type = 0;
     bp_version = 0;
@@ -383,7 +398,7 @@ namespace tx {
     m_unsigned_tx = unsigned_tx;
     m_aux_data = aux_data;
     m_tx_idx = tx_idx;
-    m_ct.tx_data = cur_tx();
+    m_ct.tx_data = cur_src_tx();
     m_multisig = false;
     m_client_version = 1;
   }
@@ -451,6 +466,41 @@ namespace tx {
     }
   }
 
+  void Signer::set_tx_input(MoneroTransactionSourceEntry * dst, size_t idx, bool need_ring_keys, bool need_ring_indices){
+    const cryptonote::tx_source_entry & src = cur_tx().sources[idx];
+    const tools::wallet2::transfer_details & transfer = get_source_transfer(idx);
+
+    dst->set_real_output(src.real_output);
+    for(size_t i = 0; i < src.outputs.size(); ++i){
+      auto & cur = src.outputs[i];
+      auto out = dst->add_outputs();
+
+      if (i == src.real_output || need_ring_indices || client_version() <= 1) {
+        out->set_idx(cur.first);
+      }
+      if (i == src.real_output || need_ring_keys || client_version() <= 1) {
+        translate_rct_key(out->mutable_key(), &(cur.second));
+      }
+    }
+
+    dst->set_real_out_tx_key(key_to_string(src.real_out_tx_key));
+    dst->set_real_output_in_tx_index(src.real_output_in_tx_index);
+
+    if (client_version() <= 1) {
+      for (auto &cur : src.real_out_additional_tx_keys) {
+        dst->add_real_out_additional_tx_keys(key_to_string(cur));
+      }
+    } else if (!src.real_out_additional_tx_keys.empty()) {
+      dst->add_real_out_additional_tx_keys(key_to_string(src.real_out_additional_tx_keys.at(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));
+    dst->set_subaddr_minor(transfer.m_subaddr_index.minor);
+  }
+
   void Signer::compute_integrated_indices(TsxData * tsx_data){
     if (m_aux_data == nullptr || m_aux_data->tx_recipients.empty()){
       return;
@@ -492,6 +542,7 @@ namespace tx {
     // extract payment ID from construction data
     auto & tsx_data = m_ct.tsx_data;
     auto & tx = cur_tx();
+    const size_t input_size = tx.sources.size();
 
     m_ct.tx.version = 2;
     m_ct.tx.unlock_time = tx.unlock_time;
@@ -500,12 +551,20 @@ namespace tx {
     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_num_inputs(static_cast<google::protobuf::uint32>(input_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_monero_version(std::string(MONERO_VERSION) + "|" + MONERO_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());
+
+    if (client_version() <= 1){
+      assign_to_repeatable(tsx_data.mutable_minor_indices(), tx.subaddr_indices.begin(), tx.subaddr_indices.end());
+    }
+
+    // TODO: use HF_VERSION_CLSAG after CLSAG is merged
+    if (tsx_data.hard_fork() >= 13){
+      throw exc::ProtocolException("CLSAG is not yet implemented");
+    }
 
     // Rsig decision
     auto rsig_data = tsx_data.mutable_rsig_data();
@@ -525,6 +584,11 @@ namespace tx {
       translate_dst_entry(dst, &cur);
     }
 
+    m_ct.source_permutation.clear();
+    for (size_t n = 0; n < input_size; ++n){
+      m_ct.source_permutation.push_back(n);
+    }
+
     compute_integrated_indices(&tsx_data);
 
     int64_t fee = 0;
@@ -559,7 +623,7 @@ namespace tx {
     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]));
+    set_tx_input(res->mutable_src_entr(), idx, false, true);
     return res;
   }
 
@@ -582,11 +646,6 @@ namespace tx {
   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]);
@@ -614,6 +673,9 @@ namespace tx {
 
   std::shared_ptr<messages::monero::MoneroTransactionInputsPermutationRequest> Signer::step_permutation(){
     sort_ki();
+    if (client_version() >= 2){
+      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());
@@ -634,17 +696,10 @@ namespace tx {
     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]));
+    set_tx_input(res->mutable_src_entr(), idx, false, false);
     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]);
-    }
-
+    res->set_orig_idx(m_ct.source_permutation[idx]);
     return res;
   }
 
@@ -657,31 +712,6 @@ namespace tx {
   }
 
   void Signer::step_all_inputs_set_ack(std::shared_ptr<const messages::monero::MoneroTransactionAllInputsSetAck> 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::monero::MoneroTransactionSetOutputRequest> Signer::step_set_output(size_t idx){
@@ -696,15 +726,6 @@ namespace tx {
     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;
   }
 
@@ -814,7 +835,7 @@ namespace tx {
   }
 
   std::shared_ptr<messages::monero::MoneroTransactionSetOutputRequest> Signer::step_rsig(size_t idx){
-    if (client_version() == 0 || !is_offloading() || !should_compute_bp_now()){
+    if (!is_offloading() || !should_compute_bp_now()){
       return nullptr;
     }
 
@@ -917,11 +938,12 @@ namespace tx {
     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]));
+    set_tx_input(res->mutable_src_entr(), idx, true, true);
     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]);
+    res->set_orig_idx(m_ct.source_permutation[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");
@@ -931,10 +953,7 @@ namespace tx {
   }
 
   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.signatures.push_back(ack->signature());
 
     // Sync updated pseudo_outputs, client_version>=1, HF10+
     if (client_version() >= 1 && ack->has_pseudo_out()){
@@ -948,12 +967,9 @@ namespace tx {
         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::monero::MoneroTransactionFinalRequest> Signer::step_final(){
-    m_ct.tx.rct_signatures = *(m_ct.rv);
     return std::make_shared<messages::monero::MoneroTransactionFinalRequest>();
   }
 
@@ -976,6 +992,42 @@ namespace tx {
     m_ct.enc_salt1 = ack->salt();
     m_ct.enc_salt2 = ack->rand_mult();
     m_ct.enc_keys = ack->tx_enc_keys();
+
+    // Opening the sealed signatures
+    if (client_version() >= 3){
+      if(!ack->has_opening_key()){
+        throw exc::ProtocolException("Client version 3+ requires sealed signatures");
+      }
+
+      for(size_t i = 0; i < m_ct.signatures.size(); ++i){
+        CHECK_AND_ASSERT_THROW_MES(m_ct.signatures[i].size() > crypto::chacha::TAG_SIZE, "Invalid signature size");
+        std::string nonce = compute_sealing_key(ack->opening_key(), i, true);
+        std::string key = compute_sealing_key(ack->opening_key(), i, false);
+        size_t plen = m_ct.signatures[i].size() - crypto::chacha::TAG_SIZE;
+        std::unique_ptr<uint8_t[]> plaintext(new uint8_t[plen]);
+        uint8_t * buff = plaintext.get();
+
+        protocol::crypto::chacha::decrypt(
+            m_ct.signatures[i].data(),
+            m_ct.signatures[i].size(),
+            reinterpret_cast<const uint8_t *>(key.data()),
+            reinterpret_cast<const uint8_t *>(nonce.data()),
+            reinterpret_cast<char *>(buff), &plen);
+        m_ct.signatures[i].assign(reinterpret_cast<const char *>(buff), plen);
+      }
+    }
+
+    // CLSAG support comes here once it is merged to the Monero
+    m_ct.rv->p.MGs.reserve(m_ct.signatures.size());
+    for(size_t i = 0; i < m_ct.signatures.size(); ++i) {
+      rct::mgSig mg;
+      if (!cn_deserialize(m_ct.signatures[i], mg)) {
+        throw exc::ProtocolException("Cannot deserialize mg[i]");
+      }
+      m_ct.rv->p.MGs.push_back(mg);
+    }
+
+    m_ct.tx.rct_signatures = *(m_ct.rv);
   }
 
   std::string Signer::store_tx_aux_info(){
diff --git a/src/device_trezor/trezor/protocol.hpp b/src/device_trezor/trezor/protocol.hpp
index f58bf1039..8fc5eba97 100644
--- a/src/device_trezor/trezor/protocol.hpp
+++ b/src/device_trezor/trezor/protocol.hpp
@@ -118,7 +118,8 @@ namespace ki {
    */
   bool key_image_data(wallet_shim * wallet,
                       const std::vector<tools::wallet2::transfer_details> & transfers,
-                      std::vector<MoneroTransferDetails> & res);
+                      std::vector<MoneroTransferDetails> & res,
+                      bool need_all_additionals=false);
 
   /**
    * Computes a hash over MoneroTransferDetails. Commitment used in the KI sync.
@@ -130,7 +131,8 @@ namespace ki {
    */
   void generate_commitment(std::vector<MoneroTransferDetails> & mtds,
                            const std::vector<tools::wallet2::transfer_details> & transfers,
-                           std::shared_ptr<messages::monero::MoneroKeyImageExportInitRequest> & req);
+                           std::shared_ptr<messages::monero::MoneroKeyImageExportInitRequest> & req,
+                           bool need_subaddr_indices=false);
 
   /**
    * Processes Live refresh step response, parses KI, checks the signature
@@ -158,13 +160,13 @@ namespace tx {
 
   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);
   ::crypto::secret_key compute_enc_key(const ::crypto::secret_key & private_view_key, const std::string & aux, const std::string & salt);
+  std::string compute_sealing_key(const std::string & master_key, size_t idx, bool is_iv=false);
 
   typedef boost::variant<rct::rangeSig, rct::Bulletproof> rsig_v;
 
@@ -198,6 +200,7 @@ namespace tx {
     std::vector<std::string> pseudo_outs_hmac;
     std::vector<std::string> couts;
     std::vector<std::string> couts_dec;
+    std::vector<std::string> signatures;
     std::vector<rct::key> rsig_gamma;
     std::string tx_prefix_hash;
     std::string enc_salt1;
@@ -221,16 +224,33 @@ namespace tx {
     unsigned m_client_version;
     bool m_multisig;
 
-    const tx_construction_data & cur_tx(){
+    const tx_construction_data & cur_src_tx() const {
       CHECK_AND_ASSERT_THROW_MES(m_tx_idx < m_unsigned_tx->txes.size(), "Invalid transaction index");
       return m_unsigned_tx->txes[m_tx_idx];
     }
 
+    const tx_construction_data & cur_tx() const {
+      return m_ct.tx_data;
+    }
+
+    const tools::wallet2::transfer_details & get_transfer(size_t idx) const {
+      CHECK_AND_ASSERT_THROW_MES(idx < m_unsigned_tx->transfers.second.size() + m_unsigned_tx->transfers.first && idx >= m_unsigned_tx->transfers.first, "Invalid transfer index");
+      return m_unsigned_tx->transfers.second[idx - m_unsigned_tx->transfers.first];
+    }
+
+    const tools::wallet2::transfer_details & get_source_transfer(size_t idx) const {
+      const auto & sel_transfers = cur_tx().selected_transfers;
+      CHECK_AND_ASSERT_THROW_MES(idx < m_ct.source_permutation.size(), "Invalid source index - permutation");
+      CHECK_AND_ASSERT_THROW_MES(m_ct.source_permutation[idx] < sel_transfers.size(), "Invalid source index");
+      return get_transfer(sel_transfers.at(m_ct.source_permutation[idx]));
+    }
+
     void extract_payment_id();
     void compute_integrated_indices(TsxData * tsx_data);
     bool should_compute_bp_now() const;
     void compute_bproof(messages::monero::MoneroTransactionRsigData & rsig_data);
     void process_bproof(rct::Bulletproof & bproof);
+    void set_tx_input(MoneroTransactionSourceEntry * dst, size_t idx, bool need_ring_keys=false, bool need_ring_indices=false);
 
   public:
     Signer(wallet_shim * wallet2, const unsigned_tx_set * unsigned_tx, size_t tx_idx = 0, hw::tx_aux_data * aux_data = nullptr);
diff --git a/src/device_trezor/trezor/transport.cpp b/src/device_trezor/trezor/transport.cpp
index 59b281f13..52bee6c6c 100644
--- a/src/device_trezor/trezor/transport.cpp
+++ b/src/device_trezor/trezor/transport.cpp
@@ -56,6 +56,11 @@ namespace trezor{
     return true;
   }
 
+  bool t_serialize(const epee::wipeable_string & in, std::string & out){
+    out.assign(in.data(), in.size());
+    return true;
+  }
+
   bool t_serialize(const json_val & in, std::string & out){
     rapidjson::StringBuffer sb;
     rapidjson::Writer<rapidjson::StringBuffer> writer(sb);
@@ -75,6 +80,11 @@ namespace trezor{
     return true;
   }
 
+  bool t_deserialize(std::string & in, epee::wipeable_string & out){
+    out = epee::wipeable_string(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");
@@ -192,61 +202,69 @@ namespace trezor{
     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();
+    epee::wipeable_string req_buff;
+    epee::wipeable_string chunk_buff;
+
+    req_buff.resize(buff_size);
+    chunk_buff.resize(REPLEN);
+
+    uint8_t * req_buff_raw = reinterpret_cast<uint8_t *>(req_buff.data());
+    uint8_t * chunk_buff_raw = reinterpret_cast<uint8_t *>(chunk_buff.data());
+
     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);
+      chunk_buff_raw[0] = '?';
+      memcpy(chunk_buff_raw + 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);
+        memset(chunk_buff_raw + 1 + to_copy, 0, REPLEN - 1 - to_copy);
       }
 
-      transport.write_chunk(chunk_buff, REPLEN);
+      transport.write_chunk(chunk_buff_raw, REPLEN);
       offset += REPLEN - 1;
     }
   }
 
   void ProtocolV1::read(Transport & transport, std::shared_ptr<google::protobuf::Message> & msg, messages::MessageType * msg_type){
-    char chunk[REPLEN];
+    epee::wipeable_string chunk_buff;
+    chunk_buff.resize(REPLEN);
+    char * chunk_buff_raw = chunk_buff.data();
 
     // Initial chunk read
-    size_t nread = transport.read_chunk(chunk, REPLEN);
+    size_t nread = transport.read_chunk(chunk_buff_raw, REPLEN);
     if (nread != REPLEN){
       throw exc::CommunicationException("Read chunk has invalid size");
     }
 
-    if (strncmp(chunk, "?##", 3) != 0){
+    if (memcmp(chunk_buff_raw, "?##", 3) != 0){
       throw exc::CommunicationException("Malformed chunk");
     }
 
     uint16_t tag;
     uint32_t len;
     nread -= 3 + 6;
-    deserialize_message_header(chunk + 3, tag, len);
+    deserialize_message_header(chunk_buff_raw + 3, tag, len);
 
-    std::string data_acc(chunk + 3 + 6, nread);
+    epee::wipeable_string data_acc(chunk_buff_raw + 3 + 6, nread);
     data_acc.reserve(len);
 
     while(nread < len){
-      const size_t cur = transport.read_chunk(chunk, REPLEN);
-      if (chunk[0] != '?'){
+      const size_t cur = transport.read_chunk(chunk_buff_raw, REPLEN);
+      if (chunk_buff_raw[0] != '?'){
         throw exc::CommunicationException("Chunk malformed");
       }
 
-      data_acc.append(chunk + 1, cur - 1);
+      data_acc.append(chunk_buff_raw + 1, cur - 1);
       nread += cur - 1;
     }
 
@@ -259,7 +277,7 @@ namespace trezor{
     }
 
     std::shared_ptr<google::protobuf::Message> msg_wrap(MessageMapper::get_message(tag));
-    if (!msg_wrap->ParseFromArray(data_acc.c_str(), len)){
+    if (!msg_wrap->ParseFromArray(data_acc.data(), len)){
       throw exc::CommunicationException("Message could not be parsed");
     }
 
@@ -426,15 +444,16 @@ namespace trezor{
 
     const auto msg_size = message_size(req);
     const auto buff_size = serialize_message_buffer_size(msg_size);
+    epee::wipeable_string req_buff;
+    req_buff.resize(buff_size);
 
-    std::unique_ptr<uint8_t[]> req_buff(new uint8_t[buff_size]);
-    uint8_t * req_buff_raw = req_buff.get();
+    uint8_t * req_buff_raw = reinterpret_cast<uint8_t *>(req_buff.data());
 
     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;
+    epee::wipeable_string res_hex;
+    epee::wipeable_string req_hex = epee::to_hex::wipeable_string(epee::span<const std::uint8_t>(req_buff_raw, buff_size));
 
     bool req_status = invoke_bridge_http(uri, req_hex, res_hex, m_http_client);
     if (!req_status){
@@ -449,15 +468,15 @@ namespace trezor{
       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)){
+    boost::optional<epee::wipeable_string> bin_data = m_response->parse_hexstr();
+    if (!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){
+    deserialize_message_header(bin_data->data(), msg_tag, msg_len);
+    if (bin_data->size() != msg_len + 6){
       throw exc::CommunicationException("Response is not well hexcoded");
     }
 
@@ -466,7 +485,7 @@ namespace trezor{
     }
 
     std::shared_ptr<google::protobuf::Message> msg_wrap(MessageMapper::get_message(msg_tag));
-    if (!msg_wrap->ParseFromArray(bin_data.c_str() + 6, msg_len)){
+    if (!msg_wrap->ParseFromArray(bin_data->data() + 6, msg_len)){
       throw exc::EncodingException("Response is not well hexcoded");
     }
     msg = msg_wrap;
diff --git a/src/device_trezor/trezor/transport.hpp b/src/device_trezor/trezor/transport.hpp
index affd91553..9a43b3637 100644
--- a/src/device_trezor/trezor/transport.hpp
+++ b/src/device_trezor/trezor/transport.hpp
@@ -66,10 +66,12 @@ namespace trezor {
 
   // Base HTTP comm serialization.
   bool t_serialize(const std::string & in, std::string & out);
+  bool t_serialize(const epee::wipeable_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(std::string & in, epee::wipeable_string & out);
   bool t_deserialize(const std::string & in, json & out);
 
   // Flexible json serialization. HTTP client tailored for bridge API
@@ -84,6 +86,13 @@ namespace trezor {
     additional_params.push_back(std::make_pair("Content-Type","application/json; charset=utf-8"));
 
     const http::http_response_info* pri = nullptr;
+    const auto data_cleaner = epee::misc_utils::create_scope_leave_handler([&]() {
+      if (!req_param.empty()) {
+        memwipe(&req_param[0], req_param.size());
+      }
+      transport.wipe_response();
+    });
+
     if(!transport.invoke(uri, method, req_param, timeout, &pri, std::move(additional_params)))
     {
       MERROR("Failed to invoke http request to  " << uri);
@@ -103,7 +112,7 @@ namespace trezor {
       return false;
     }
 
-    return t_deserialize(pri->m_body, result_struct);
+    return t_deserialize(const_cast<http::http_response_info*>(pri)->m_body, result_struct);
   }
 
   // Forward decl
@@ -186,7 +195,7 @@ namespace trezor {
     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<epee::wipeable_string> m_response;
     boost::optional<json> m_device_info;
   };