New wire protocol for reward script.

Define a new wire protocol version, and for peers that match the
version, send the reward script as explicit part of the masternode
broadcast messages.

Also, if the reward script is not the default value, include it in the
signature message of the broadcast (so that the field is authenticated
by the collateral signature).

Until the protocol version is bumped on the network (which is not yet
the case with this commit), masternodes with non-default reward script
will not be accepted as valid.

Author: domob1812

divi/src/masternode.cpp

@@ -13,6 +13,8 @@
 #include <streams.h>
 #include <net.h>
 
+#include <sstream>
+
 CAmount CMasternode::GetTierCollateralAmount(const MasternodeTier tier)
 {
     const auto& collateralMap = Params().MasternodeCollateralMap();
@@ -267,10 +269,28 @@ void CMasternodeBroadcast::Relay() const
 
 std::string CMasternodeBroadcast::getMessageToSign() const
 {
-    std::string vchPubKey(pubKeyCollateralAddress.begin(), pubKeyCollateralAddress.end());
-    std::string vchPubKey2(pubKeyMasternode.begin(), pubKeyMasternode.end());
+    std::ostringstream message;
+
+    message << addr.ToString();
+    message << sigTime;
+    message << std::string(pubKeyCollateralAddress.begin(), pubKeyCollateralAddress.end());
+
+    /* The signature must commit also to the reward script.  We do this by
+       including it in the signed message if and only if it does not match
+       the collateral address.  This makes sure that the signature format
+       is backwards compatible for situations where we just have the
+       default reward script.  */
+    if (rewardScript != GetDefaultRewardScript()) {
+        /* Include a "marker", so that e.g. a zero-length script is different
+           from the default situation.  */
+        message << "rs";
+        message << std::string(rewardScript.begin(), rewardScript.end());
+    }
+
+    message << std::string(pubKeyMasternode.begin(), pubKeyMasternode.end());
+    message << protocolVersion;
 
-    return addr.ToString() + boost::lexical_cast<std::string>(sigTime) + vchPubKey + vchPubKey2 + boost::lexical_cast<std::string>(protocolVersion);
+    return message.str();
 }
 
 uint256 CMasternodeBroadcast::GetHash() const

divi/src/masternode.h

@@ -171,12 +171,14 @@ class CMasternodeBroadcast : public CMasternode
         READWRITE(vin);
         READWRITE(addr);
         READWRITE(pubKeyCollateralAddress);
-        /* The wire format (for which the serialisation here is relevant)
-           does not include the reward script yet.  */
-        if (ser_action.ForRead()) {
-            rewardScript = GetDefaultRewardScript();
-        } else if (rewardScript != GetDefaultRewardScript()) {
-            LogPrintf("WARNING: CMasternodeBroadcast - ignoring changed reward script for serialisation of %s\n", vin.prevout.ToString());
+        if (nVersion >= MN_REWARD_SCRIPT_VERSION) {
+            READWRITE(rewardScript);
+        } else {
+            if (ser_action.ForRead()) {
+                rewardScript = GetDefaultRewardScript();
+            } else if (rewardScript != GetDefaultRewardScript()) {
+                LogPrintf("WARNING: CMasternodeBroadcast - ignoring changed reward script for serialisation of %s\n", vin.prevout.ToString());
+            }
         }
         READWRITE(pubKeyMasternode);
         READWRITE(signature);

divi/src/masternodeman.cpp

@@ -228,6 +228,12 @@ bool CMasternodeMan::CheckInputsForMasternode(const CMasternodeBroadcast& mnb, i
 
 bool CMasternodeMan::CheckMasternodeBroadcastContext(CMasternodeBroadcast& mnb, int& nDoS)
 {
+    /* Until the protocol is updated, do not allow custom reward scripts.  */
+    if (ActiveProtocol() < MN_REWARD_SCRIPT_VERSION && mnb.rewardScript != mnb.GetDefaultRewardScript()) {
+        LogPrintf("%s : mnb - reward script does not match collateral address for %s\n", __func__, mnb.vin.prevout.ToString());
+        return false;
+    }
+
     // make sure signature isn't in the future (past is OK)
     if (mnb.sigTime > GetAdjustedTime() + 60 * 60) {
         LogPrintf("%s : mnb - Signature rejected, too far into the future %s\n", __func__, mnb.vin.prevout.hash);

divi/src/version-util.cpp

@@ -2,7 +2,7 @@
 
 #include <Logging.h>
 
-static int version = MIN_PEER_PROTO_VERSION_AFTER_ENFORCEMENT;
+static int version = MN_REWARD_SCRIPT_VERSION;
 const int& PROTOCOL_VERSION(version);
 
 void SetProtocolVersion(const int newVersion)

divi/src/version.h

@@ -33,6 +33,9 @@ static constexpr int MEMPOOL_GD_VERSION = 60002;
 //! "filter*" commands are disabled without NODE_BLOOM after and including this version
 static constexpr int NO_BLOOM_VERSION = 70005;
 
+//! include explicit reward script in masternode broadcasts
+static constexpr int MN_REWARD_SCRIPT_VERSION = 71000;
+
 /** The current protocol version.   Since it can be changed through -protocolversion
  *  for testing, it is not a constexpr but a real variable.  */
 extern const int& PROTOCOL_VERSION;