add consensus.mandatory_coinbase_destination

Author: instagibbs

src/chainparams.cpp

@@ -420,6 +420,11 @@ class CCustomParams : public CRegTestParams {
         consensus.nMinimumChainWork = uint256S(args.GetArg("-con_nminimumchainwork", "0x0"));
         consensus.defaultAssumeValid = uint256S(args.GetArg("-con_defaultassumevalid", "0x00"));
 
+        // All non-zero coinbase outputs must go to this scriptPubKey
+        std::vector<unsigned char> man_bytes = ParseHex(gArgs.GetArg("-con_mandatorycoinbase", ""));
+        consensus.mandatory_coinbase_destination = CScript(man_bytes.begin(), man_bytes.end()); // Blank script allows any coinbase destination
+
+
         nPruneAfterHeight = (uint64_t)args.GetArg("-npruneafterheight", nPruneAfterHeight);
         fDefaultConsistencyChecks = args.GetBoolArg("-fdefaultconsistencychecks", fDefaultConsistencyChecks);
         fMineBlocksOnDemand = args.GetBoolArg("-fmineblocksondemand", fMineBlocksOnDemand);

src/chainparamsbase.cpp

@@ -22,6 +22,7 @@ void SetupChainParamsBaseOptions()
                                    "This is intended for regression testing tools and app development.", true, OptionsCategory::CHAINPARAMS);
     gArgs.AddArg("-testnet", "Use the test chain", false, OptionsCategory::CHAINPARAMS);
     gArgs.AddArg("-vbparams=deployment:start:end", "Use given start/end times for specified version bits deployment (regtest or custom only)", true, OptionsCategory::CHAINPARAMS);
+    gArgs.AddArg("-con_mandatorycoinbase", "All non-zero valued coinbase outputs must go to this scriptPubKey, if set.", false, OptionsCategory::CHAINPARAMS);
     gArgs.AddArg("-seednode=<ip>", "Use specified node as seed node. This option can be specified multiple times to connect to multiple nodes. (custom only)", true, OptionsCategory::CHAINPARAMS);
 }
 

src/consensus/params.h

@@ -11,6 +11,8 @@
 #include <map>
 #include <string>
 
+#include <script/script.h> // mandatory_coinbase_destination
+
 namespace Consensus {
 
 enum DeploymentPos
@@ -75,6 +77,9 @@ struct Params {
     int64_t DifficultyAdjustmentInterval() const { return nPowTargetTimespan / nPowTargetSpacing; }
     uint256 nMinimumChainWork;
     uint256 defaultAssumeValid;
+
+    // Elements-specific chainparams
+    CScript mandatory_coinbase_destination;
 };
 } // namespace Consensus
 

src/validation.cpp

@@ -1850,6 +1850,17 @@ bool CChainState::ConnectBlock(const CBlock& block, CValidationState& state, CBl
 
     nBlocksTotal++;
 
+    // Check that all non-zero coinbase outputs pay to the required destination
+    const CScript& mandatory_coinbase_destination = chainparams.GetConsensus().mandatory_coinbase_destination;
+    if (mandatory_coinbase_destination != CScript()) {
+        for (auto& txout : block.vtx[0]->vout) {
+            if (txout.scriptPubKey != mandatory_coinbase_destination && txout.nValue != 0) {
+                return state.DoS(100, error("ConnectBlock(): Coinbase outputs didnt match required scriptPubKey"),
+                                 REJECT_INVALID, "bad-coinbase-txos");
+            }
+        }
+    }
+
     bool fScriptChecks = true;
     if (!hashAssumeValid.IsNull()) {
         // We've been configured with the hash of a block which has been externally verified to have a valid history.