wallet: cold wallet transaction signing

This change adds the ability to create a new unsigned transaction
from a watch only wallet, and save it to a file. This file can
then be moved to another computer/VM where a cold wallet may load
it, sign it, and save it. That cold wallet does not need to have
a blockchain nor daemon. The signed transaction file can then be
moved back to the watch only wallet, which can load it and send
it to the daemon.

Two new simplewallet commands to use it:
sign_transfer (on the cold wallet)
submit_transfer (on the watch only wallet)

The transfer command used on a watch only wallet now writes an
unsigned transaction set in a file called 'unsigned_monero_tx'
instead of submitting the tx to the daemon as a normal wallet does.
The signed tx file is called 'signed_monero_tx'.

1 files changed, 4 insertions, 4 deletions

diff --git a/tests/unit_tests/output_selection.cpp b/tests/unit_tests/output_selection.cpp
index 4344d1ffc..d26f5ae1a 100644
--- a/tests/unit_tests/output_selection.cpp
+++ b/tests/unit_tests/output_selection.cpp
@@ -56,14 +56,14 @@ static tools::wallet2::transfer_container make_transfers_container(size_t N)
     auto i = std::find(unused_indices.begin(), unused_indices.end(), idx); \
     ASSERT_TRUE(i != unused_indices.end()); \
     unused_indices.erase(i); \
-    selected.push_back(transfers.begin() + idx); \
+    selected.push_back(idx); \
   } while(0)
 
 #define PICK(expected) \
   do { \
     size_t idx = w.pop_best_value_from(transfers, unused_indices, selected); \
     ASSERT_EQ(expected, idx); \
-    selected.push_back(transfers.begin() + idx); \
+    selected.push_back(idx); \
   } while(0)
 
 TEST(select_outputs, one_out_of_N)
@@ -76,7 +76,7 @@ TEST(select_outputs, one_out_of_N)
   tools::wallet2::transfer_container transfers = make_transfers_container(10);
   transfers[6].m_block_height = 700;
   std::vector<size_t> unused_indices({0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
-  std::list<tools::wallet2::transfer_container::iterator> selected;
+  std::list<size_t> selected;
   SELECT(2);
   PICK(6);
 }
@@ -93,7 +93,7 @@ TEST(select_outputs, order)
   transfers[3].m_block_height = 716;
   transfers[4].m_block_height = 701;
   std::vector<size_t> unused_indices({0, 1, 2, 3, 4});
-  std::list<tools::wallet2::transfer_container::iterator> selected;
+  std::list<size_t> selected;
   SELECT(0);
   PICK(3); // first the one that's far away
   PICK(2); // then the one that's close