Merge pull request #1541

0d3918e1 Wallet api: Update trustedDaemon when daemon is changed (Jaquee)
dbb838f4 GUI cold signing (Jaquee)
afb85a02 Wallet API: functions for supporting/creating view only wallets (Jaquee)

10 files changed, 525 insertions, 9 deletions

diff --git a/src/wallet/CMakeLists.txt b/src/wallet/CMakeLists.txt
index 056a1ca10..53b0a794f 100644
--- a/src/wallet/CMakeLists.txt
+++ b/src/wallet/CMakeLists.txt
@@ -40,7 +40,8 @@ set(wallet_sources
   api/transaction_history.cpp
   api/pending_transaction.cpp
   api/utils.cpp
-  api/address_book.cpp)
+  api/address_book.cpp
+  api/unsigned_transaction.cpp)
 
 set(wallet_api_headers
     wallet2_api.h)
@@ -60,7 +61,8 @@ set(wallet_private_headers
   api/transaction_history.h
   api/pending_transaction.h
   api/common_defines.h
-  api/address_book.h)
+  api/address_book.h
+  api/unsigned_transaction.h)
 
 monero_private_headers(wallet
   ${wallet_private_headers})
diff --git a/src/wallet/api/pending_transaction.cpp b/src/wallet/api/pending_transaction.cpp
index 6586d0c48..760c84f4f 100644
--- a/src/wallet/api/pending_transaction.cpp
+++ b/src/wallet/api/pending_transaction.cpp
@@ -51,7 +51,7 @@ PendingTransaction::~PendingTransaction() {}
 PendingTransactionImpl::PendingTransactionImpl(WalletImpl &wallet)
     : m_wallet(wallet)
 {
-
+  m_status = Status_Ok;
 }
 
 PendingTransactionImpl::~PendingTransactionImpl()
@@ -77,19 +77,39 @@ std::vector<std::string> PendingTransactionImpl::txid() const
     return txid;
 }
 
-bool PendingTransactionImpl::commit()
+bool PendingTransactionImpl::commit(const std::string &filename, bool overwrite)
 {
 
     LOG_PRINT_L3("m_pending_tx size: " << m_pending_tx.size());
 
     try {
+      // Save tx to file
+      if (!filename.empty()) {
+        boost::system::error_code ignore;
+        bool tx_file_exists = boost::filesystem::exists(filename, ignore);
+        if(tx_file_exists && !overwrite){
+          m_errorString = string(tr("Attempting to save transaction to file, but specified file(s) exist. Exiting to not risk overwriting. File:")) + filename;
+          m_status = Status_Error;
+          LOG_ERROR(m_errorString);
+          return false;
+        }
+        bool r = m_wallet.m_wallet->save_tx(m_pending_tx, filename);
+        if (!r) {
+          m_errorString = tr("Failed to write transaction(s) to file");
+          m_status = Status_Error;
+        } else {
+          m_status = Status_Ok;
+        }
+      }
+      // Commit tx
+      else {
         while (!m_pending_tx.empty()) {
             auto & ptx = m_pending_tx.back();
             m_wallet.m_wallet->commit_tx(ptx);
-            // success_msg_writer(true) << tr("Money successfully sent, transaction ") << get_transaction_hash(ptx.tx);
             // if no exception, remove element from vector
             m_pending_tx.pop_back();
         } // TODO: extract method;
+      }
     } catch (const tools::error::daemon_busy&) {
         // TODO: make it translatable with "tr"?
         m_errorString = tr("daemon is busy. Please try again later.");
@@ -100,7 +120,11 @@ bool PendingTransactionImpl::commit()
     } catch (const tools::error::tx_rejected& e) {
         std::ostringstream writer(m_errorString);
         writer << (boost::format(tr("transaction %s was rejected by daemon with status: ")) % get_transaction_hash(e.tx())) <<  e.status();
+        std::string reason = e.reason();
         m_status = Status_Error;
+        m_errorString = writer.str();
+        if (!reason.empty())
+          m_errorString  += string(tr(". Reason: ")) + reason;
     } catch (std::exception &e) {
         m_errorString = string(tr("Unknown exception: ")) + e.what();
         m_status = Status_Error;
diff --git a/src/wallet/api/pending_transaction.h b/src/wallet/api/pending_transaction.h
index 47ccdec76..d85a686fd 100644
--- a/src/wallet/api/pending_transaction.h
+++ b/src/wallet/api/pending_transaction.h
@@ -45,7 +45,7 @@ public:
     ~PendingTransactionImpl();
     int status() const;
     std::string errorString() const;
-    bool commit();
+    bool commit(const std::string &filename = "", bool overwrite = false);
     uint64_t amount() const;
     uint64_t dust() const;
     uint64_t fee() const;
diff --git a/src/wallet/api/unsigned_transaction.cpp b/src/wallet/api/unsigned_transaction.cpp
new file mode 100644
index 000000000..84ec2d9d2
--- /dev/null
+++ b/src/wallet/api/unsigned_transaction.cpp
@@ -0,0 +1,279 @@
+// Copyright (c) 2014-2017, 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.
+//
+// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
+
+#include "unsigned_transaction.h"
+#include "wallet.h"
+#include "common_defines.h"
+
+#include "cryptonote_core/cryptonote_format_utils.h"
+#include "cryptonote_core/cryptonote_basic_impl.h"
+#include "cryptonote_core/cryptonote_format_utils.h"
+
+#include <memory>
+#include <vector>
+#include <sstream>
+#include <boost/format.hpp>
+
+using namespace std;
+
+namespace Monero {
+
+UnsignedTransaction::~UnsignedTransaction() {}
+
+
+UnsignedTransactionImpl::UnsignedTransactionImpl(WalletImpl &wallet)
+    : m_wallet(wallet)
+{
+  m_status = Status_Ok;
+}
+
+UnsignedTransactionImpl::~UnsignedTransactionImpl()
+{
+    LOG_PRINT_L3("Unsigned tx deleted");
+}
+
+int UnsignedTransactionImpl::status() const
+{
+    return m_status;
+}
+
+string UnsignedTransactionImpl::errorString() const
+{
+    return m_errorString;
+}
+
+bool UnsignedTransactionImpl::sign(const std::string &signedFileName)
+{
+  if(m_wallet.watchOnly())
+  {
+     m_errorString = tr("This is a watch only wallet");
+     m_status = Status_Error;
+     return false;
+  }
+  std::vector<tools::wallet2::pending_tx> ptx;
+  try
+  {
+    bool r = m_wallet.m_wallet->sign_tx(m_unsigned_tx_set, signedFileName, ptx);
+    if (!r)
+    {
+      m_errorString = tr("Failed to sign transaction");
+      m_status = Status_Error;
+      return false;
+    }
+  }
+  catch (const std::exception &e)
+  {
+    m_errorString = string(tr("Failed to sign transaction")) + e.what();
+    m_status = Status_Error;
+    return false;
+  }
+  return true;
+}
+
+//----------------------------------------------------------------------------------------------------
+bool UnsignedTransactionImpl::checkLoadedTx(const std::function<size_t()> get_num_txes, const std::function<const tools::wallet2::tx_construction_data&(size_t)> &get_tx, const std::string &extra_message)
+{
+  // gather info to ask the user
+  uint64_t amount = 0, amount_to_dests = 0, change = 0;
+  size_t min_mixin = ~0;
+  std::unordered_map<std::string, uint64_t> dests;
+  const std::string wallet_address = m_wallet.m_wallet->get_account().get_public_address_str(m_wallet.m_wallet->testnet());
+  for (size_t n = 0; n < get_num_txes(); ++n)
+  {
+    const tools::wallet2::tx_construction_data &cd = get_tx(n);
+    for (size_t s = 0; s < cd.sources.size(); ++s)
+    {
+      amount += cd.sources[s].amount;
+      size_t mixin = cd.sources[s].outputs.size() - 1;
+      if (mixin < min_mixin)
+        min_mixin = mixin;
+    }
+    for (size_t d = 0; d < cd.splitted_dsts.size(); ++d)
+    {
+      const cryptonote::tx_destination_entry &entry = cd.splitted_dsts[d];
+      std::string address = get_account_address_as_str(m_wallet.m_wallet->testnet(), entry.addr);
+      std::unordered_map<std::string,uint64_t>::iterator i = dests.find(address);
+      if (i == dests.end())
+        dests.insert(std::make_pair(address, entry.amount));
+      else
+        i->second += entry.amount;
+      amount_to_dests += entry.amount;
+    }
+    if (cd.change_dts.amount > 0)
+    {
+      std::unordered_map<std::string, uint64_t>::iterator it = dests.find(get_account_address_as_str(m_wallet.m_wallet->testnet(), cd.change_dts.addr));
+      if (it == dests.end())
+      {
+        m_status = Status_Error;
+        m_errorString = tr("Claimed change does not go to a paid address");
+        return false;
+      }
+      if (it->second < cd.change_dts.amount)
+      {
+        m_status = Status_Error;
+        m_errorString = tr("Claimed change is larger than payment to the change address");
+        return  false;
+      }
+      if (memcmp(&cd.change_dts.addr, &get_tx(0).change_dts.addr, sizeof(cd.change_dts.addr)))
+      {
+        m_status = Status_Error;
+        m_errorString = tr("Change does to more than one address");
+        return false;
+      }
+      change += cd.change_dts.amount;
+      it->second -= cd.change_dts.amount;
+      if (it->second == 0)
+        dests.erase(get_account_address_as_str(m_wallet.m_wallet->testnet(), cd.change_dts.addr));
+    }
+  }
+  std::string dest_string;
+  for (std::unordered_map<std::string, uint64_t>::const_iterator i = dests.begin(); i != dests.end(); )
+  {
+    dest_string += (boost::format(tr("sending %s to %s")) % cryptonote::print_money(i->second) % i->first).str();
+    ++i;
+    if (i != dests.end())
+      dest_string += ", ";
+  }
+  if (dest_string.empty())
+    dest_string = tr("with no destinations");
+
+  std::string change_string;
+  if (change > 0)
+  {
+    std::string address = get_account_address_as_str(m_wallet.m_wallet->testnet(), get_tx(0).change_dts.addr);
+    change_string += (boost::format(tr("%s change to %s")) % cryptonote::print_money(change) % address).str();
+  }
+  else
+    change_string += tr("no change");
+  uint64_t fee = amount - amount_to_dests;
+  m_confirmationMessage = (boost::format(tr("Loaded %lu transactions, for %s, fee %s, %s, %s, with min mixin %lu. %s")) % (unsigned long)get_num_txes() % cryptonote::print_money(amount) % cryptonote::print_money(fee) % dest_string % change_string % (unsigned long)min_mixin % extra_message).str();
+  return true;
+}
+
+std::vector<uint64_t> UnsignedTransactionImpl::amount() const
+{
+    std::vector<uint64_t> result;
+    for (const auto &utx : m_unsigned_tx_set.txes)   {
+        for (const auto &unsigned_dest : utx.dests) {
+            result.push_back(unsigned_dest.amount);
+        }
+    }
+    return result;
+}
+
+std::vector<uint64_t> UnsignedTransactionImpl::fee() const
+{
+    std::vector<uint64_t> result;
+    for (const auto &utx : m_unsigned_tx_set.txes) {
+        uint64_t fee = 0;
+        for (const auto &i: utx.sources) fee += i.amount;
+        for (const auto &i: utx.splitted_dsts) fee -= i.amount;
+        result.push_back(fee);
+    }   
+    return result;
+} 
+
+std::vector<uint64_t> UnsignedTransactionImpl::mixin() const
+{
+    std::vector<uint64_t> result;    
+    for (const auto &utx: m_unsigned_tx_set.txes) {
+        size_t min_mixin = ~0;
+        // TODO: Is this loop needed or is sources[0] ?
+        for (size_t s = 0; s < utx.sources.size(); ++s) {
+            size_t mixin = utx.sources[s].outputs.size() - 1;
+                if (mixin < min_mixin)
+                    min_mixin = mixin;
+        }
+        result.push_back(min_mixin);
+    }
+    return result;
+}    
+
+uint64_t UnsignedTransactionImpl::txCount() const
+{
+    return m_unsigned_tx_set.txes.size();
+}
+
+std::vector<std::string> UnsignedTransactionImpl::paymentId() const 
+{
+    std::vector<string> result;
+    for (const auto &utx: m_unsigned_tx_set.txes) {     
+        crypto::hash payment_id = cryptonote::null_hash;
+        cryptonote::tx_extra_nonce extra_nonce;
+        std::vector<cryptonote::tx_extra_field> tx_extra_fields;
+        cryptonote::parse_tx_extra(utx.extra, tx_extra_fields);
+        if (cryptonote::find_tx_extra_field_by_type(tx_extra_fields, extra_nonce))
+        {
+          crypto::hash8 payment_id8 = cryptonote::null_hash8;
+          if(cryptonote::get_encrypted_payment_id_from_tx_extra_nonce(extra_nonce.nonce, payment_id8))
+          {
+              // We can't decrypt short pid without recipient key.
+              memcpy(payment_id.data, payment_id8.data, 8);
+          }
+          else if (!cryptonote::get_payment_id_from_tx_extra_nonce(extra_nonce.nonce, payment_id))
+          {
+            payment_id = cryptonote::null_hash;
+          }      
+        }
+        if(payment_id != cryptonote::null_hash)
+            result.push_back(epee::string_tools::pod_to_hex(payment_id));
+        else
+            result.push_back("");
+    }
+    return result;
+}
+
+std::vector<std::string> UnsignedTransactionImpl::recipientAddress() const 
+{
+    // TODO: return integrated address if short payment ID exists
+    std::vector<string> result;
+    for (const auto &utx: m_unsigned_tx_set.txes) {
+        result.push_back(cryptonote::get_account_address_as_str(m_wallet.m_wallet->testnet(), utx.dests[0].addr));
+    }
+    return result;
+}
+
+uint64_t UnsignedTransactionImpl::minMixinCount() const
+{    
+    uint64_t min_mixin = ~0;  
+    for (const auto &utx: m_unsigned_tx_set.txes) {
+        for (size_t s = 0; s < utx.sources.size(); ++s) {
+            size_t mixin = utx.sources[s].outputs.size() - 1;
+                if (mixin < min_mixin)
+                    min_mixin = mixin;
+        }
+    }
+    return min_mixin;
+}
+
+} // namespace
+
+namespace Bitmonero = Monero;
+
diff --git a/src/wallet/api/unsigned_transaction.h b/src/wallet/api/unsigned_transaction.h
new file mode 100644
index 000000000..8038334e4
--- /dev/null
+++ b/src/wallet/api/unsigned_transaction.h
@@ -0,0 +1,76 @@
+// Copyright (c) 2014-2016, 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.
+//
+// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
+
+#include "wallet/wallet2_api.h"
+#include "wallet/wallet2.h"
+
+#include <string>
+#include <vector>
+
+
+namespace Monero {
+
+class WalletImpl;
+class UnsignedTransactionImpl : public UnsignedTransaction
+{
+public:
+    UnsignedTransactionImpl(WalletImpl &wallet);
+    ~UnsignedTransactionImpl();
+    int status() const;
+    std::string errorString() const;
+    std::vector<uint64_t> amount() const;
+    std::vector<uint64_t> dust() const;
+    std::vector<uint64_t> fee() const;
+    std::vector<uint64_t> mixin() const;
+    std::vector<std::string> paymentId() const;
+    std::vector<std::string> recipientAddress() const;
+    uint64_t txCount() const;
+    // sign txs and save to file
+    bool sign(const std::string &signedFileName);
+    std::string confirmationMessage() const {return m_confirmationMessage;}
+    uint64_t minMixinCount() const;
+
+private:
+    // Callback function to check all loaded tx's and generate confirmationMessage
+    bool checkLoadedTx(const std::function<size_t()> get_num_txes, const std::function<const tools::wallet2::tx_construction_data&(size_t)> &get_tx, const std::string &extra_message);
+    
+    friend class WalletImpl;
+    WalletImpl &m_wallet;
+
+    int  m_status;
+    std::string m_errorString;
+    tools::wallet2::unsigned_tx_set m_unsigned_tx_set;
+    std::string m_confirmationMessage;
+};
+
+
+}
+
+namespace Bitmonero = Monero;
diff --git a/src/wallet/api/wallet.cpp b/src/wallet/api/wallet.cpp
index 0fb832d65..10a75d4c9 100644
--- a/src/wallet/api/wallet.cpp
+++ b/src/wallet/api/wallet.cpp
@@ -31,6 +31,7 @@
 
 #include "wallet.h"
 #include "pending_transaction.h"
+#include "unsigned_transaction.h"
 #include "transaction_history.h"
 #include "address_book.h"
 #include "common_defines.h"
@@ -51,6 +52,8 @@ namespace {
     static const int    DEFAULT_REFRESH_INTERVAL_MILLIS = 1000 * 10;
     // limit maximum refresh interval as one minute
     static const int    MAX_REFRESH_INTERVAL_MILLIS = 1000 * 60 * 1;
+    // Default refresh interval when connected to remote node
+    static const int    DEFAULT_REMOTE_NODE_REFRESH_INTERVAL_MILLIS = 1000 * 10;
 }
 
 struct Wallet2CallbackImpl : public tools::i_wallet2_callback
@@ -623,6 +626,50 @@ int WalletImpl::autoRefreshInterval() const
     return m_refreshIntervalMillis;
 }
 
+UnsignedTransaction *WalletImpl::loadUnsignedTx(const std::string &unsigned_filename) {
+  clearStatus();
+  UnsignedTransactionImpl * transaction = new UnsignedTransactionImpl(*this);
+  if (!m_wallet->load_unsigned_tx(unsigned_filename, transaction->m_unsigned_tx_set)){
+    m_errorString = tr("Failed to load unsigned transactions");
+    m_status = Status_Error;
+  }
+  
+  // Check tx data and construct confirmation message
+  std::string extra_message;
+  if (!transaction->m_unsigned_tx_set.transfers.empty())
+    extra_message = (boost::format("%u outputs to import. ") % (unsigned)transaction->m_unsigned_tx_set.transfers.size()).str();
+  transaction->checkLoadedTx([&transaction](){return transaction->m_unsigned_tx_set.txes.size();}, [&transaction](size_t n)->const tools::wallet2::tx_construction_data&{return transaction->m_unsigned_tx_set.txes[n];}, extra_message);
+  m_status = transaction->status();
+  m_errorString = transaction->errorString(); 
+    
+  return transaction;
+}
+
+bool WalletImpl::submitTransaction(const string &fileName) {
+  clearStatus();
+  PendingTransactionImpl * transaction = new PendingTransactionImpl(*this);
+
+// bool r = m_wallet->load_tx(fileName, transaction->m_pending_tx, [&](const tools::wallet2::signed_tx_set &tx){ return accept_loaded_tx(tx); });
+  bool r = m_wallet->load_tx(fileName, transaction->m_pending_tx);
+  if (!r) {
+    m_errorString = tr("Failed to load transaction from file");
+    m_status = Status_Ok;
+    delete transaction;
+    return false;
+  }
+  
+  if(!transaction->commit()) {
+    m_errorString = transaction->m_errorString;
+    m_status = Status_Error;
+    delete transaction;
+    return false;
+  }
+
+  delete transaction;
+
+  return true;
+}
+
 // TODO:
 // 1 - properly handle payment id (add another menthod with explicit 'payment_id' param)
 // 2 - check / design how "Transaction" can be single interface
@@ -640,6 +687,7 @@ PendingTransaction *WalletImpl::createTransaction(const string &dst_addr, const
     clearStatus();
     // Pause refresh thread while creating transaction
     pauseRefresh();
+      
     cryptonote::account_public_address addr;
 
     // indicates if dst_addr is integrated address (address + payment_id)
@@ -1140,7 +1188,12 @@ void WalletImpl::doInit(const string &daemon_address, uint64_t upper_transaction
 
     if (Utils::isAddressLocal(daemon_address)) {
         this->setTrustedDaemon(true);
+        m_refreshIntervalMillis = DEFAULT_REFRESH_INTERVAL_MILLIS;
+    } else {
+        this->setTrustedDaemon(false);
+        m_refreshIntervalMillis = DEFAULT_REMOTE_NODE_REFRESH_INTERVAL_MILLIS;
     }
+        
 
 }
 
diff --git a/src/wallet/api/wallet.h b/src/wallet/api/wallet.h
index 41b3b22f3..5b4064e8e 100644
--- a/src/wallet/api/wallet.h
+++ b/src/wallet/api/wallet.h
@@ -43,6 +43,7 @@
 namespace Monero {
 class TransactionHistoryImpl;
 class PendingTransactionImpl;
+class UnsignedTransactionImpl;
 class AddressBookImpl;
 struct Wallet2CallbackImpl;
 
@@ -99,6 +100,8 @@ public:
                                         optional<uint64_t> amount, uint32_t mixin_count,
                                         PendingTransaction::Priority priority = PendingTransaction::Priority_Low);
     virtual PendingTransaction * createSweepUnmixableTransaction();
+    bool submitTransaction(const std::string &fileName);
+    virtual UnsignedTransaction * loadUnsignedTx(const std::string &unsigned_filename);
 
     virtual void disposeTransaction(PendingTransaction * t);
     virtual TransactionHistory * history() const;
@@ -126,6 +129,7 @@ private:
 
 private:
     friend class PendingTransactionImpl;
+    friend class UnsignedTransactionImpl;    
     friend class TransactionHistoryImpl;
     friend class Wallet2CallbackImpl;
     friend class AddressBookImpl;
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index 639c2c5fc..b57ea9273 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -3017,7 +3017,7 @@ bool wallet2::save_tx(const std::vector<pending_tx>& ptx_vector, const std::stri
   return epee::file_io_utils::save_string_to_file(filename, std::string(UNSIGNED_TX_PREFIX) + oss.str());  
 }
 //----------------------------------------------------------------------------------------------------
-bool wallet2::sign_tx(const std::string &unsigned_filename, const std::string &signed_filename, std::vector<wallet2::pending_tx> &txs, std::function<bool(const unsigned_tx_set&)> accept_func)
+bool wallet2::load_unsigned_tx(const std::string &unsigned_filename, unsigned_tx_set &exported_txs)
 {
   std::string s;
   boost::system::error_code errcode;
@@ -3038,7 +3038,6 @@ bool wallet2::sign_tx(const std::string &unsigned_filename, const std::string &s
     LOG_PRINT_L0("Bad magic from " << unsigned_filename);
     return false;
   }
-  unsigned_tx_set exported_txs;
   s = s.substr(magiclen);
   try
   {
@@ -3053,12 +3052,26 @@ bool wallet2::sign_tx(const std::string &unsigned_filename, const std::string &s
   }
   LOG_PRINT_L1("Loaded tx unsigned data from binary: " << exported_txs.txes.size() << " transactions");
 
+  return true;
+}
+//----------------------------------------------------------------------------------------------------
+bool wallet2::sign_tx(const std::string &unsigned_filename, const std::string &signed_filename, std::vector<wallet2::pending_tx> &txs, std::function<bool(const unsigned_tx_set&)> accept_func)
+{
+  unsigned_tx_set exported_txs;
+  if(!load_unsigned_tx(unsigned_filename, exported_txs))
+    return false;
+  
   if (accept_func && !accept_func(exported_txs))
   {
     LOG_PRINT_L1("Transactions rejected by callback");
     return false;
   }
+  return sign_tx(exported_txs, signed_filename, txs);
+}
 
+//----------------------------------------------------------------------------------------------------
+bool wallet2::sign_tx(unsigned_tx_set &exported_txs, const std::string &signed_filename, std::vector<wallet2::pending_tx> &txs)
+{
   import_outputs(exported_txs.transfers);
 
   // sign the transactions
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index 2d4896b55..ddd315145 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -226,6 +226,8 @@ namespace tools
       tx_construction_data construction_data;
     };
 
+    // The term "Unsigned tx" is not really a tx since it's not signed yet.
+    // It doesnt have tx hash, key and the integrated address is not separated into addr + payment id.
     struct unsigned_tx_set
     {
       std::vector<tx_construction_data> txes;
@@ -387,7 +389,12 @@ namespace tools
     void commit_tx(pending_tx& ptx_vector);
     void commit_tx(std::vector<pending_tx>& ptx_vector);
     bool save_tx(const std::vector<pending_tx>& ptx_vector, const std::string &filename);
+    // load unsigned tx from file and sign it. Takes confirmation callback as argument. Used by the cli wallet
     bool sign_tx(const std::string &unsigned_filename, const std::string &signed_filename, std::vector<wallet2::pending_tx> &ptx, std::function<bool(const unsigned_tx_set&)> accept_func = NULL);
+    // sign unsigned tx. Takes unsigned_tx_set as argument. Used by GUI
+    bool sign_tx(unsigned_tx_set &exported_txs, const std::string &signed_filename, std::vector<wallet2::pending_tx> &ptx);
+    // load unsigned_tx_set from file. 
+    bool load_unsigned_tx(const std::string &unsigned_filename, unsigned_tx_set &exported_txs);
     bool load_tx(const std::string &signed_filename, std::vector<tools::wallet2::pending_tx> &ptx, std::function<bool(const signed_tx_set&)> accept_func = NULL);
     std::vector<pending_tx> create_transactions(std::vector<cryptonote::tx_destination_entry> dsts, const size_t fake_outs_count, const uint64_t unlock_time, uint32_t priority, const std::vector<uint8_t> extra, bool trusted_daemon);
     std::vector<wallet2::pending_tx> create_transactions_2(std::vector<cryptonote::tx_destination_entry> dsts, const size_t fake_outs_count, const uint64_t unlock_time, uint32_t priority, const std::vector<uint8_t> extra, bool trusted_daemon);
diff --git a/src/wallet/wallet2_api.h b/src/wallet/wallet2_api.h
index d4c0388a6..a3ff5ac91 100644
--- a/src/wallet/wallet2_api.h
+++ b/src/wallet/wallet2_api.h
@@ -77,7 +77,8 @@ struct PendingTransaction
     virtual ~PendingTransaction() = 0;
     virtual int status() const = 0;
     virtual std::string errorString() const = 0;
-    virtual bool commit() = 0;
+    // commit transaction or save to file if filename is provided.
+    virtual bool commit(const std::string &filename = "", bool overwrite = false) = 0;
     virtual uint64_t amount() const = 0;
     virtual uint64_t dust() const = 0;
     virtual uint64_t fee() const = 0;
@@ -90,6 +91,48 @@ struct PendingTransaction
 };
 
 /**
+ * @brief Transaction-like interface for sending money
+ */
+struct UnsignedTransaction
+{
+    enum Status {
+        Status_Ok,
+        Status_Error,
+        Status_Critical
+    };
+
+    enum Priority {
+        Priority_Low = 1,
+        Priority_Medium = 2,
+        Priority_High = 3,
+        Priority_Last
+    };
+
+    virtual ~UnsignedTransaction() = 0;
+    virtual int status() const = 0;
+    virtual std::string errorString() const = 0;
+    virtual std::vector<uint64_t> amount() const = 0;
+    virtual std::vector<uint64_t>  fee() const = 0;
+    virtual std::vector<uint64_t> mixin() const = 0;
+    // returns a string with information about all transactions.
+    virtual std::string confirmationMessage() const = 0;
+    virtual std::vector<std::string> paymentId() const = 0;
+    virtual std::vector<std::string> recipientAddress() const = 0;
+    virtual uint64_t minMixinCount() const = 0;
+    /*!
+     * \brief txCount - number of transactions current transaction will be splitted to
+     * \return
+     */
+    virtual uint64_t txCount() const = 0;
+   /*!
+    * @brief sign - Sign txs and saves to file
+    * @param signedFileName
+    * return - true on success
+    */
+    virtual bool sign(const std::string &signedFileName) = 0;
+};
+
+/**
  * @brief The TransactionInfo - interface for displaying transaction information
  */
 struct TransactionInfo
@@ -441,12 +484,27 @@ struct Wallet
      */
 
     virtual PendingTransaction * createSweepUnmixableTransaction() = 0;
+    
+   /*!
+    * \brief loadUnsignedTx  - creates transaction from unsigned tx file
+    * \return                - UnsignedTransaction object. caller is responsible to check UnsignedTransaction::status()
+    *                          after object returned
+    */
+    virtual UnsignedTransaction * loadUnsignedTx(const std::string &unsigned_filename) = 0;
+    
+   /*!
+    * \brief submitTransaction - submits transaction in signed tx file
+    * \return                  - true on success
+    */
+    virtual bool submitTransaction(const std::string &fileName) = 0;
+    
 
     /*!
      * \brief disposeTransaction - destroys transaction object
      * \param t -  pointer to the "PendingTransaction" object. Pointer is not valid after function returned;
      */
     virtual void disposeTransaction(PendingTransaction * t) = 0;
+
     virtual TransactionHistory * history() const = 0;
     virtual AddressBook * addressBook() const = 0;
     virtual void setListener(WalletListener *) = 0;