wallet: fix output collision detection for view wallets

View wallets do not have the spend secret key, and are thus
unable to derive key images for incoming outputs. Moreover,
a previous patch set key images to zero as a means to mark
an output as having an unknown key image, so they could be
filled in when importing key images at a later time. That
later patch caused spurious collisions. We now use public
keys to detect duplicate outputs. Public keys obtained from
the blockchain are checked to be identical to the ones
derived locally, so can't be spoofed.

1 files changed, 22 insertions, 2 deletions

diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index b34db0b6c..2b69dc64a 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -109,9 +109,11 @@ namespace tools
       rct::key m_mask;
       uint64_t m_amount;
       bool m_rct;
+      bool m_key_image_known;
 
       bool is_rct() const { return m_rct; }
       uint64_t amount() const { return m_amount; }
+      const crypto::public_key &get_public_key() const { return boost::get<const cryptonote::txout_to_key>(m_tx.vout[m_internal_output_index].target).key; }
     };
 
     struct payment_details
@@ -409,6 +411,19 @@ namespace tools
       a & m_unconfirmed_payments;
       if(ver < 14)
         return;
+      if(ver < 15)
+      {
+        // we're loading an older wallet without a pubkey map, rebuild it
+        for (size_t i = 0; i < m_transfers.size(); ++i)
+        {
+          const transfer_details &td = m_transfers[i];
+          const cryptonote::tx_out &out = td.m_tx.vout[td.m_internal_output_index];
+          const cryptonote::txout_to_key &o = boost::get<const cryptonote::txout_to_key>(out.target);
+          m_pub_keys.emplace(o.key, i);
+        }
+        return;
+      }
+      a & m_pub_keys;
     }
 
     /*!
@@ -543,6 +558,7 @@ namespace tools
     transfer_container m_transfers;
     payment_container m_payments;
     std::unordered_map<crypto::key_image, size_t> m_key_images;
+    std::unordered_map<crypto::public_key, size_t> m_pub_keys;
     cryptonote::account_public_address m_account_public_address;
     std::unordered_map<crypto::hash, std::string> m_tx_notes;
     uint64_t m_upper_transaction_size_limit; //TODO: auto-calc this value or request from daemon, now use some fixed value
@@ -567,8 +583,8 @@ namespace tools
     bool m_confirm_missing_payment_id;
   };
 }
-BOOST_CLASS_VERSION(tools::wallet2, 14)
-BOOST_CLASS_VERSION(tools::wallet2::transfer_details, 4)
+BOOST_CLASS_VERSION(tools::wallet2, 15)
+BOOST_CLASS_VERSION(tools::wallet2::transfer_details, 5)
 BOOST_CLASS_VERSION(tools::wallet2::payment_details, 1)
 BOOST_CLASS_VERSION(tools::wallet2::unconfirmed_transfer_details, 6)
 BOOST_CLASS_VERSION(tools::wallet2::confirmed_transfer_details, 3)
@@ -597,6 +613,7 @@ namespace boost
         {
           x.m_rct = x.m_tx.vout[x.m_internal_output_index].amount == 0;
         }
+        x.m_key_image_known = true;
     }
 
     template <class Archive>
@@ -644,6 +661,9 @@ namespace boost
         return;
       }
       a & x.m_rct;
+      if (ver < 5)
+        return;
+      a & x.m_key_image_known;
     }
 
     template <class Archive>