New "Halfway RingCT" outputs for coinbase transactions

When RingCT is enabled, outputs from coinbase transactions
are created as a single output, and stored as RingCT output,
with a fake mask. Their amount is not hidden on the blockchain
itself, but they are then able to be used as fake inputs in
a RingCT ring. Since the output amounts are hidden, their
"dustiness" is not an obstacle anymore to mixing, and this
makes the coinbase transactions a lot smaller, as well as
helping the TXO set to grow more slowly.

Also add a new "Null" type of rct signature, which decreases
the size required when no signatures are to be stored, as
in a coinbase tx.

tests/core_tests/block_validation.cpp

@@ -337,6 +337,7 @@ bool gen_block_miner_tx_has_2_in::generate(std::vector<test_event_entry>& events
   se.amount = blk_0.miner_tx.vout[0].amount;
   se.push_output(0, boost::get<txout_to_key>(blk_0.miner_tx.vout[0].target).key, se.amount);
   se.real_output = 0;
+  se.rct = false;
   se.real_out_tx_key = get_tx_pub_key_from_extra(blk_0.miner_tx);
   se.real_output_in_tx_index = 0;
   std::vector<tx_source_entry> sources;
@@ -379,6 +380,7 @@ bool gen_block_miner_tx_with_txin_to_key::generate(std::vector<test_event_entry>
   se.amount = blk_1.miner_tx.vout[0].amount;
   se.push_output(0, boost::get<txout_to_key>(blk_1.miner_tx.vout[0].target).key, se.amount);
   se.real_output = 0;
+  se.rct = false;
   se.real_out_tx_key = get_tx_pub_key_from_extra(blk_1.miner_tx);
   se.real_output_in_tx_index = 0;
   std::vector<tx_source_entry> sources;

tests/core_tests/chaingen.cpp

@@ -458,6 +458,7 @@ bool fill_tx_sources(std::vector<tx_source_entry>& sources, const std::vector<te
               continue;
 
             ts.real_output = realOutput;
+            ts.rct = false;
 
             sources.push_back(ts);
 

tests/core_tests/double_spend.inl

@@ -130,6 +130,7 @@ bool gen_double_spend_in_tx<txs_keeped_by_block>::generate(std::vector<test_even
   se.amount = tx_0.vout[0].amount;
   se.push_output(0, boost::get<cryptonote::txout_to_key>(tx_0.vout[0].target).key, se.amount);
   se.real_output = 0;
+  se.rct = false;
   se.real_out_tx_key = get_tx_pub_key_from_extra(tx_0);
   se.real_output_in_tx_index = 0;
   sources.push_back(se);

tests/core_tests/integer_overflow.cpp

@@ -63,6 +63,7 @@ namespace
     se.amount = tx.vout[out_idx].amount;
     se.push_output(0, boost::get<cryptonote::txout_to_key>(tx.vout[out_idx].target).key, se.amount);
     se.real_output = 0;
+    se.rct = false;
     se.real_out_tx_key = get_tx_pub_key_from_extra(tx);
     se.real_output_in_tx_index = out_idx;
 

tests/core_tests/rct.cpp

@@ -57,8 +57,8 @@ bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& ev
     miner_accounts[n].generate();
     CHECK_AND_ASSERT_MES(generator.construct_block_manually(blocks[n], *prev_block, miner_accounts[n],
         test_generator::bf_major_ver | test_generator::bf_minor_ver | test_generator::bf_timestamp | test_generator::bf_hf_version,
-        4, 4, prev_block->timestamp + DIFFICULTY_BLOCKS_ESTIMATE_TIMESPAN * 2, // v2 has blocks twice as long
-          crypto::hash(), 0, transaction(), std::vector<crypto::hash>(), 0, 0, 4),
+        2, 2, prev_block->timestamp + DIFFICULTY_BLOCKS_ESTIMATE_TIMESPAN * 2, // v2 has blocks twice as long
+          crypto::hash(), 0, transaction(), std::vector<crypto::hash>(), 0, 0, 2),
         false, "Failed to generate block");
     events.push_back(blocks[n]);
     prev_block = blocks + n;
@@ -74,8 +74,8 @@ bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& ev
       cryptonote::block blk;
       CHECK_AND_ASSERT_MES(generator.construct_block_manually(blk, blk_last, miner_account,
           test_generator::bf_major_ver | test_generator::bf_minor_ver | test_generator::bf_timestamp | test_generator::bf_hf_version,
-          4, 4, blk_last.timestamp + DIFFICULTY_BLOCKS_ESTIMATE_TIMESPAN * 2, // v2 has blocks twice as long
-          crypto::hash(), 0, transaction(), std::vector<crypto::hash>(), 0, 0, 4),
+          2, 2, blk_last.timestamp + DIFFICULTY_BLOCKS_ESTIMATE_TIMESPAN * 2, // v2 has blocks twice as long
+          crypto::hash(), 0, transaction(), std::vector<crypto::hash>(), 0, 0, 2),
           false, "Failed to generate block");
       events.push_back(blk);
       blk_last = blk;
@@ -104,6 +104,7 @@ bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& ev
     src.real_output = n;
     src.real_output_in_tx_index = index_in_tx;
     src.mask = rct::identity();
+    src.rct = false;
 
     //fill outputs entry
     tx_destination_entry td;
@@ -135,9 +136,9 @@ bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& ev
     }
 
     CHECK_AND_ASSERT_MES(generator.construct_block_manually(blk_txes[n], blk_last, miner_account,
-        test_generator::bf_major_ver | test_generator::bf_minor_ver | test_generator::bf_timestamp | test_generator::bf_tx_hashes | test_generator::bf_hf_version,
+        test_generator::bf_major_ver | test_generator::bf_minor_ver | test_generator::bf_timestamp | test_generator::bf_tx_hashes | test_generator::bf_hf_version | test_generator::bf_max_outs,
         4, 4, blk_last.timestamp + DIFFICULTY_BLOCKS_ESTIMATE_TIMESPAN * 2, // v2 has blocks twice as long
-        crypto::hash(), 0, transaction(), starting_rct_tx_hashes, 0, 0, 4),
+        crypto::hash(), 0, transaction(), starting_rct_tx_hashes, 0, 6, 4),
         false, "Failed to generate block");
     events.push_back(blk_txes[n]);
     blk_last = blk_txes[n];
@@ -149,9 +150,9 @@ bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& ev
     {
       cryptonote::block blk;
       CHECK_AND_ASSERT_MES(generator.construct_block_manually(blk, blk_last, miner_account,
-          test_generator::bf_major_ver | test_generator::bf_minor_ver | test_generator::bf_timestamp | test_generator::bf_hf_version,
+          test_generator::bf_major_ver | test_generator::bf_minor_ver | test_generator::bf_timestamp | test_generator::bf_hf_version | test_generator::bf_max_outs,
           4, 4, blk_last.timestamp + DIFFICULTY_BLOCKS_ESTIMATE_TIMESPAN * 2, // v2 has blocks twice as long
-          crypto::hash(), 0, transaction(), std::vector<crypto::hash>(), 0, 0, 4),
+          crypto::hash(), 0, transaction(), std::vector<crypto::hash>(), 0, 6, 4),
           false, "Failed to generate block");
       events.push_back(blk);
       blk_last = blk;
@@ -161,7 +162,9 @@ bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& ev
 
   // create a tx from the requested ouputs
   std::vector<tx_source_entry> sources;
-  size_t rct_idx = 0, pre_rct_idx = 0;
+  size_t global_rct_idx = 6; // skip first coinbase (6 outputs)
+  size_t rct_idx = 0;
+  size_t pre_rct_idx = 0;
   for (size_t out_idx_idx = 0; out_idx[out_idx_idx] >= 0; ++out_idx_idx) {
     sources.resize(sources.size()+1);
     tx_source_entry& src = sources.back();
@@ -173,12 +176,16 @@ bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& ev
       src.real_out_tx_key = get_tx_pub_key_from_extra(rct_txes[rct_idx/4]);
       src.real_output_in_tx_index = rct_idx&3;
       src.mask = rct_tx_masks[rct_idx];
+      src.rct = true;
       for (int m = 0; m <= mixin; ++m) {
         rct::ctkey ctkey;
         ctkey.dest = rct::pk2rct(boost::get<txout_to_key>(rct_txes[rct_idx/4].vout[rct_idx&3].target).key);
         ctkey.mask = rct_txes[rct_idx/4].rct_signatures.outPk[rct_idx&3].mask;
-        src.outputs.push_back(std::make_pair(rct_idx, ctkey));
+        src.outputs.push_back(std::make_pair(global_rct_idx, ctkey));
         ++rct_idx;
+        ++global_rct_idx;
+        if (global_rct_idx % 10 == 0)
+          global_rct_idx += 6; // skip the coinbase
       }
     }
     else
@@ -188,6 +195,7 @@ bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& ev
       src.real_out_tx_key = cryptonote::get_tx_pub_key_from_extra(blocks[pre_rct_idx].miner_tx);
       src.real_output_in_tx_index = 4;
       src.mask = rct::identity();
+      src.rct = false;
       for (int m = 0; m <= mixin; ++m) {
         src.push_output(m, boost::get<txout_to_key>(blocks[pre_rct_idx].miner_tx.vout[4].target).key, src.amount);
         ++pre_rct_idx;

tests/core_tests/rct.h

@@ -81,7 +81,7 @@ private:
 
 template<>
 struct get_test_options<gen_rct_tx_validation_base> {
-  const std::pair<uint8_t, uint64_t> hard_forks[2] = {std::make_pair(1, 0), std::make_pair(4, 1)};
+  const std::pair<uint8_t, uint64_t> hard_forks[3] = {std::make_pair(1, 0), std::make_pair(2, 1), std::make_pair(4, 65)};
   const cryptonote::test_options test_options = {
     hard_forks
   };

tests/core_tests/transaction_tests.cpp

@@ -97,6 +97,7 @@ bool test_transaction_generation_and_ring_signature()
 
     src.real_out_tx_key = cryptonote::get_tx_pub_key_from_extra(tx_mine_2);
     src.real_output = 1;
+    src.rct = false;
     src.real_output_in_tx_index = 0;
   }
   //fill outputs entry

tests/core_tests/v2_tests.cpp

@@ -96,6 +96,7 @@ bool gen_v2_tx_validation_base::generate_with(std::vector<test_event_entry>& eve
     }
     src.real_out_tx_key = cryptonote::get_tx_pub_key_from_extra(blocks[0].miner_tx);
     src.real_output = 0;
+    src.rct = false;
     src.real_output_in_tx_index = out_idx[out_idx_idx];
   }
 

tests/functional_tests/transactions_generation_from_blockchain.cpp

@@ -113,6 +113,7 @@ bool make_tx(blockchain_storage& bch)
     src.real_out_tx_key = td.m_tx.tx_pub_key;
     src.real_output = interted_it - src.outputs.begin();
     src.real_output_in_tx_index = td.m_internal_output_index;
+    src.rct = false;
     ++i;
   }
 

tests/performance_tests/multi_tx_test_base.h

@@ -72,6 +72,7 @@ public:
     source_entry.real_output_in_tx_index = 0;
     source_entry.outputs.swap(output_entries);
     source_entry.real_output = real_source_idx;
+    source_entry.rct = false;
 
     m_sources.push_back(source_entry);