Fix sending outputs from a tx with more than one pubkey

A bug in cold signing caused a spurious pubkey to be included
in transactions, so we need to ensure we use the correct one
when sending outputs from one of those.

src/cryptonote_core/cryptonote_format_utils.cpp

@@ -320,26 +320,26 @@ namespace cryptonote
     return true;
   }
   //---------------------------------------------------------------
-  crypto::public_key get_tx_pub_key_from_extra(const std::vector<uint8_t>& tx_extra)
+  crypto::public_key get_tx_pub_key_from_extra(const std::vector<uint8_t>& tx_extra, size_t pk_index)
   {
     std::vector<tx_extra_field> tx_extra_fields;
     parse_tx_extra(tx_extra, tx_extra_fields);
 
     tx_extra_pub_key pub_key_field;
-    if(!find_tx_extra_field_by_type(tx_extra_fields, pub_key_field))
+    if(!find_tx_extra_field_by_type(tx_extra_fields, pub_key_field, pk_index))
       return null_pkey;
 
     return pub_key_field.pub_key;
   }
   //---------------------------------------------------------------
-  crypto::public_key get_tx_pub_key_from_extra(const transaction_prefix& tx_prefix)
+  crypto::public_key get_tx_pub_key_from_extra(const transaction_prefix& tx_prefix, size_t pk_index)
   {
-    return get_tx_pub_key_from_extra(tx_prefix.extra);
+    return get_tx_pub_key_from_extra(tx_prefix.extra, pk_index);
   }
   //---------------------------------------------------------------
-  crypto::public_key get_tx_pub_key_from_extra(const transaction& tx)
+  crypto::public_key get_tx_pub_key_from_extra(const transaction& tx, size_t pk_index)
   {
-    return get_tx_pub_key_from_extra(tx.extra);
+    return get_tx_pub_key_from_extra(tx.extra, pk_index);
   }
   //---------------------------------------------------------------
   bool add_tx_pub_key_to_extra(transaction& tx, const crypto::public_key& tx_pub_key)
@@ -534,8 +534,10 @@ namespace cryptonote
 
     uint64_t summary_inputs_money = 0;
     //fill inputs
+    int idx = -1;
     BOOST_FOREACH(const tx_source_entry& src_entr,  sources)
     {
+      ++idx;
       if(src_entr.real_output >= src_entr.outputs.size())
       {
         LOG_ERROR("real_output index (" << src_entr.real_output << ")bigger than output_keys.size()=" << src_entr.outputs.size());
@@ -553,9 +555,11 @@ namespace cryptonote
       //check that derivated key is equal with real output key
       if( !(in_ephemeral.pub == src_entr.outputs[src_entr.real_output].second.dest) )
       {
-        LOG_ERROR("derived public key mismatch with output public key! "<< ENDL << "derived_key:"
+        LOG_ERROR("derived public key mismatch with output public key at index " << idx << ", real out " << src_entr.real_output << "! "<< ENDL << "derived_key:"
           << string_tools::pod_to_hex(in_ephemeral.pub) << ENDL << "real output_public_key:"
           << string_tools::pod_to_hex(src_entr.outputs[src_entr.real_output].second) );
+        LOG_ERROR("amount " << src_entr.amount << ", rct " << src_entr.rct);
+        LOG_ERROR("tx pubkey " << src_entr.real_out_tx_key << ", real_output_in_tx_index " << src_entr.real_output_in_tx_index);
         return false;
       }
 

src/cryptonote_core/cryptonote_format_utils.h

@@ -104,9 +104,9 @@ namespace cryptonote
   }
 
   bool parse_tx_extra(const std::vector<uint8_t>& tx_extra, std::vector<tx_extra_field>& tx_extra_fields);
-  crypto::public_key get_tx_pub_key_from_extra(const std::vector<uint8_t>& tx_extra);
+  crypto::public_key get_tx_pub_key_from_extra(const std::vector<uint8_t>& tx_extra, size_t pk_index = 0);
-  crypto::public_key get_tx_pub_key_from_extra(const transaction_prefix& tx);
+  crypto::public_key get_tx_pub_key_from_extra(const transaction_prefix& tx, size_t pk_index = 0);
-  crypto::public_key get_tx_pub_key_from_extra(const transaction& tx);
+  crypto::public_key get_tx_pub_key_from_extra(const transaction& tx, size_t pk_index = 0);
   bool add_tx_pub_key_to_extra(transaction& tx, const crypto::public_key& tx_pub_key);
   bool add_extra_nonce_to_tx_extra(std::vector<uint8_t>& tx_extra, const blobdata& extra_nonce);
   bool remove_field_from_tx_extra(std::vector<uint8_t>& tx_extra, const std::type_info &type);

src/wallet/wallet2.cpp

@@ -846,6 +846,7 @@ void wallet2::process_new_transaction(const cryptonote::transaction& tx, const s
             td.m_key_image = ki[o];
             td.m_key_image_known = !m_watch_only;
             td.m_amount = tx.vout[o].amount;
+            td.m_pk_index = pk_index - 1;
             if (td.m_amount == 0)
             {
               td.m_mask = mask[o];
@@ -894,6 +895,7 @@ void wallet2::process_new_transaction(const cryptonote::transaction& tx, const s
 	    td.m_tx = (const cryptonote::transaction_prefix&)tx;
 	    td.m_txid = txid();
             td.m_amount = tx.vout[o].amount;
+            td.m_pk_index = pk_index - 1;
             if (td.m_amount == 0)
             {
               td.m_mask = mask[o];
@@ -3623,7 +3625,7 @@ void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_ent
     real_oe.second.dest = rct::pk2rct(boost::get<txout_to_key>(td.m_tx.vout[td.m_internal_output_index].target).key);
     real_oe.second.mask = rct::commit(td.amount(), td.m_mask);
     *it_to_replace = real_oe;
-    src.real_out_tx_key = get_tx_pub_key_from_extra(td.m_tx);
+    src.real_out_tx_key = get_tx_pub_key_from_extra(td.m_tx, td.m_pk_index);
     src.real_output = it_to_replace - src.outputs.begin();
     src.real_output_in_tx_index = td.m_internal_output_index;
     detail::print_source_entry(src);
@@ -3699,6 +3701,9 @@ void wallet2::transfer_selected_rct(std::vector<cryptonote::tx_destination_entry
   uint64_t upper_transaction_size_limit = get_upper_tranaction_size_limit();
   uint64_t needed_money = fee;
   LOG_PRINT_L2("transfer: starting with fee " << print_money (needed_money));
+  LOG_PRINT_L0("selected transfers: ");
+  for (auto t: selected_transfers)
+    LOG_PRINT_L2("  " << t);
 
   // calculate total amount being sent to all destinations
   // throw if total amount overflows uint64_t
@@ -3759,7 +3764,7 @@ void wallet2::transfer_selected_rct(std::vector<cryptonote::tx_destination_entry
     real_oe.second.dest = rct::pk2rct(boost::get<txout_to_key>(td.m_tx.vout[td.m_internal_output_index].target).key);
     real_oe.second.mask = rct::commit(td.amount(), td.m_mask);
     *it_to_replace = real_oe;
-    src.real_out_tx_key = get_tx_pub_key_from_extra(td.m_tx);
+    src.real_out_tx_key = get_tx_pub_key_from_extra(td.m_tx, td.m_pk_index);
     src.real_output = it_to_replace - src.outputs.begin();
     src.real_output_in_tx_index = td.m_internal_output_index;
     src.mask = td.m_mask;

src/wallet/wallet2.h

@@ -129,6 +129,7 @@ namespace tools
       uint64_t m_amount;
       bool m_rct;
       bool m_key_image_known;
+      size_t m_pk_index;
 
       bool is_rct() const { return m_rct; }
       uint64_t amount() const { return m_amount; }
@@ -147,6 +148,7 @@ namespace tools
         FIELD(m_amount)
         FIELD(m_rct)
         FIELD(m_key_image_known)
+        FIELD(m_pk_index)
       END_SERIALIZE()
     };
 
@@ -644,7 +646,7 @@ namespace tools
   };
 }
 BOOST_CLASS_VERSION(tools::wallet2, 15)
-BOOST_CLASS_VERSION(tools::wallet2::transfer_details, 6)
+BOOST_CLASS_VERSION(tools::wallet2::transfer_details, 7)
 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)
@@ -677,6 +679,10 @@ namespace boost
         {
           x.m_key_image_known = true;
         }
+        if (ver < 7)
+        {
+          x.m_pk_index = 0;
+        }
     }
 
     template <class Archive>
@@ -738,6 +744,12 @@ namespace boost
         return;
       }
       a & x.m_key_image_known;
+      if (ver < 7)
+      {
+        initialize_transfer_details(a, x, ver);
+        return;
+      }
+      a & x.m_pk_index;
     }
 
     template <class Archive>