Auto merge of #1017 - ebfull:coinbase-must-be-protected, r=ebfull

Enforce that coinbases must be protected

This PR forces miners to place their funds in the private value transfer system, making "transparent coins" opt-in for users, and increasing privacy for all participants on a systemic level.

Closes #101.

src/test/coins_tests.cpp

@@ -6,6 +6,9 @@
 #include "random.h"
 #include "uint256.h"
 #include "test/test_bitcoin.h"
+#include "consensus/validation.h"
+#include "main.h"
+#include "undo.h"
 
 #include <vector>
 #include <map>
@@ -475,4 +478,48 @@ BOOST_AUTO_TEST_CASE(coins_cache_simulation_test)
     BOOST_CHECK(missed_an_entry);
 }
 
+BOOST_AUTO_TEST_CASE(coins_coinbase_spends)
+{
+    CCoinsViewTest base;
+    CCoinsViewCacheTest cache(&base);
+
+    // Create coinbase transaction
+    CMutableTransaction mtx;
+    mtx.vin.resize(1);
+    mtx.vin[0].scriptSig = CScript() << OP_1;
+    mtx.vin[0].nSequence = 0;
+    mtx.vout.resize(1);
+    mtx.vout[0].nValue = 500;
+    mtx.vout[0].scriptPubKey = CScript() << OP_1;
+
+    CTransaction tx(mtx);
+
+    BOOST_CHECK(tx.IsCoinBase());
+
+    CValidationState state;
+    UpdateCoins(tx, state, cache, 100);
+
+    // Create coinbase spend
+    CMutableTransaction mtx2;
+    mtx2.vin.resize(1);
+    mtx2.vin[0].prevout = COutPoint(tx.GetHash(), 0);
+    mtx2.vin[0].scriptSig = CScript() << OP_1;
+    mtx2.vin[0].nSequence = 0;
+
+    {
+        CTransaction tx2(mtx2);
+        BOOST_CHECK(NonContextualCheckInputs(tx2, state, cache, false, SCRIPT_VERIFY_NONE, false, Params().GetConsensus()));
+    }
+
+    mtx2.vout.resize(1);
+    mtx2.vout[0].nValue = 500;
+    mtx2.vout[0].scriptPubKey = CScript() << OP_1;
+
+    {
+        CTransaction tx2(mtx2);
+        BOOST_CHECK(!NonContextualCheckInputs(tx2, state, cache, false, SCRIPT_VERIFY_NONE, false, Params().GetConsensus()));
+        BOOST_CHECK(state.GetRejectReason() == "bad-txns-coinbase-spend-has-transparent-outputs");
+    }
+}
+
 BOOST_AUTO_TEST_SUITE_END()

src/test/miner_tests.cpp

@@ -147,6 +147,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
 
     LOCK(cs_main);
     fCheckpointsEnabled = false;
+    fCoinbaseEnforcedProtectionEnabled = false;
 
     // We can't make transactions until we have inputs
     // Therefore, load 100 blocks :)
@@ -415,6 +416,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
         delete tx;
 
     fCheckpointsEnabled = true;
+    fCoinbaseEnforcedProtectionEnabled = true;
 }
 
 BOOST_AUTO_TEST_SUITE_END()