Introduce dummy (ping-like) contributions for the dummy DKG (#2542)

* Implement creation and propagation of dummy contributions

These act as a ping which is broadcast a few blocks before the dummy
commitments are created. They are meant to determine online/offline members.

* Use information about received dummy contributions to determine validMembers

* Fix PoSe tests

* Fix dummy DKG phase progress in PoSe tests and give tests more time

Mine one block at a time until we reach the mining phase.

qa/rpc-tests/dip3-deterministicmns.py

@@ -360,14 +360,14 @@ class DIP3Test(BitcoinTestFramework):
             punished = False
             banned = False
             t = time.time()
-            while (not punished or not banned) and (time.time() - t) < 60:
+            while (not punished or not banned) and (time.time() - t) < 120:
                 time.sleep(1)
 
-                # 2 dummy phases
-                for j in range(2):
-                    self.nodes[0].generate(2)
+                # 10 blocks until we can mine the dummy commitment
+                for j in range(10):
+                    self.nodes[0].generate(1)
                     self.sync_all()
-                    time.sleep(1)
+                    time.sleep(0.5)
 
                 info = self.nodes[0].protx('info', mn.protx_hash)
                 if not punished:

src/llmq/quorums_dummydkg.cpp

@@ -27,7 +27,28 @@ CDummyDKG* quorumDummyDKG;
 
 void CDummyDKG::ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStream& vRecv, CConnman& connman)
 {
-    if (strCommand == NetMsgType::QDCOMMITMENT) {
+    if (strCommand == NetMsgType::QCONTRIB) {
+        if (!sporkManager.IsSporkActive(SPORK_17_QUORUM_DKG_ENABLED)) {
+            return;
+        }
+
+        CDummyContribution qc;
+        try {
+            vRecv >> qc;
+        } catch (...) {
+            // When we switch to the real DKG, non-upgraded nodes will get to this point. Let them just ignore the
+            // incompatible messages
+            return;
+        }
+
+        uint256 hash = ::SerializeHash(qc);
+        {
+            LOCK(cs_main);
+            connman.RemoveAskFor(hash);
+        }
+
+        ProcessDummyContribution(pfrom->id, qc);
+    } else if (strCommand == NetMsgType::QDCOMMITMENT) {
         if (!Params().GetConsensus().fLLMQAllowDummyCommitments) {
             Misbehaving(pfrom->id, 100);
             return;
@@ -49,6 +70,89 @@ void CDummyDKG::ProcessMessage(CNode* pfrom, const std::string& strCommand, CDat
     }
 }
 
+void CDummyDKG::ProcessDummyContribution(NodeId from, const llmq::CDummyContribution& qc)
+{
+    if (!Params().GetConsensus().llmqs.count((Consensus::LLMQType)qc.llmqType)) {
+        LOCK(cs_main);
+        LogPrintf("CDummyDKG::%s -- invalid commitment type %d, peer=%d\n", __func__,
+                  qc.llmqType, from);
+        if (from != -1) {
+            Misbehaving(from, 100);
+        }
+        return;
+    }
+
+    auto type = (Consensus::LLMQType)qc.llmqType;
+    const auto& params = Params().GetConsensus().llmqs.at(type);
+
+    int curQuorumHeight;
+    const CBlockIndex* quorumIndex;
+    {
+        LOCK(cs_main);
+        curQuorumHeight = chainActive.Height() - (chainActive.Height() % params.dkgInterval);
+        quorumIndex = chainActive[curQuorumHeight];
+    }
+    uint256 quorumHash = quorumIndex->GetBlockHash();
+    if (qc.quorumHash != quorumHash) {
+        LogPrintf("CDummyDKG::%s -- dummy contrinution for wrong quorum, peer=%d\n", __func__,
+                  from);
+        return;
+    }
+
+    auto members = CLLMQUtils::GetAllQuorumMembers(type, qc.quorumHash);
+    if (members.size() != params.size) {
+        LOCK(cs_main);
+        LogPrintf("CDummyDKG::%s -- invalid members count %d, peer=%d\n", __func__,
+                  members.size(), from);
+        if (from != -1) {
+            Misbehaving(from, 100);
+        }
+        return;
+    }
+    if (qc.signer >= members.size()) {
+        LOCK(cs_main);
+        LogPrintf("CDummyDKG::%s -- invalid signer %d, peer=%d\n", __func__,
+                  qc.signer, from);
+        if (from != -1) {
+            Misbehaving(from, 100);
+        }
+        return;
+    }
+
+    auto signer = members[qc.signer];
+
+    {
+        LOCK(sessionCs);
+        if (curSessions[type].dummyContributionsFromMembers.count(signer->proTxHash)) {
+            return;
+        }
+    }
+
+    // verify member sig
+    if (!qc.sig.VerifyInsecure(signer->pdmnState->pubKeyOperator, qc.GetSignHash())) {
+        LOCK(cs_main);
+        LogPrintf("CDummyDKG::%s -- invalid memberSig, peer=%d\n", __func__,
+                  from);
+        if (from != -1) {
+            Misbehaving(from, 100);
+        }
+        return;
+    }
+
+    LogPrintf("CDummyDKG::%s -- processed dummy contribution for quorum %s:%d, signer=%d, peer=%d\n", __func__,
+              qc.quorumHash.ToString(), qc.llmqType, qc.signer, from);
+
+    uint256 hash = ::SerializeHash(qc);
+    {
+        LOCK(sessionCs);
+        curSessions[type].dummyContributions[hash] = qc;
+        curSessions[type].dummyContributionsFromMembers[signer->proTxHash] = hash;
+    }
+
+    CInv inv(MSG_QUORUM_DUMMY_CONTRIBUTION, hash);
+    g_connman->RelayInv(inv, DMN_PROTO_VERSION);
+}
+
 void CDummyDKG::ProcessDummyCommitment(NodeId from, const llmq::CDummyCommitment& qc)
 {
     if (!Params().GetConsensus().llmqs.count((Consensus::LLMQType)qc.llmqType)) {
@@ -174,16 +278,6 @@ void CDummyDKG::ProcessDummyCommitment(NodeId from, const llmq::CDummyCommitment
     uint256 hash = ::SerializeHash(qc);
     {
         LOCK(sessionCs);
-
-        // Mark all members as bad initially and clear that state when we receive a valid dummy commitment from them
-        // This information is then used in the next sessions to determine which ones are valid
-        if (curSessions[type].dummyCommitments.empty()) {
-            for (const auto& dmn : members) {
-                curSessions[type].badMembers.emplace(dmn->proTxHash);
-            }
-        }
-
-        curSessions[type].badMembers.erase(signer->proTxHash);
         curSessions[type].dummyCommitments[hash] = qc;
         curSessions[type].dummyCommitmentsFromMembers[commitmentHash][signer->proTxHash] = hash;
     }
@@ -215,13 +309,52 @@ void CDummyDKG::UpdatedBlockTip(const CBlockIndex* pindex, bool fInitialDownload
         const auto& params = p.second;
         int phaseIndex = pindex->nHeight % params.dkgInterval;
         if (phaseIndex == 0) {
-            CreateDummyCommitment(params.type, pindex);
+            CreateDummyContribution(params.type, pindex);
         } else if (phaseIndex == params.dkgPhaseBlocks * 2) {
+            CreateDummyCommitment(params.type, pindex);
+        } else if (phaseIndex == params.dkgPhaseBlocks * 4) {
             CreateFinalCommitment(params.type, pindex);
         }
     }
 }
 
+void CDummyDKG::CreateDummyContribution(Consensus::LLMQType llmqType, const CBlockIndex* pindex)
+{
+    const auto& params = Params().GetConsensus().llmqs.at(llmqType);
+    int quorumHeight = pindex->nHeight - (pindex->nHeight % params.dkgInterval);
+    const CBlockIndex* quorumIndex;
+    {
+        LOCK(cs_main);
+        quorumIndex = chainActive[quorumHeight];
+    }
+    uint256 quorumHash = quorumIndex->GetBlockHash();
+
+    auto members = CLLMQUtils::GetAllQuorumMembers(llmqType, quorumHash);
+    if (members.size() != params.size) {
+        return;
+    }
+
+    int myIdx = -1;
+    for (size_t i = 0; i < members.size(); i++) {
+        if (members[i]->collateralOutpoint == activeMasternodeInfo.outpoint) {
+            myIdx = (int)i;
+            break;
+        }
+    }
+    if (myIdx == -1) {
+        return;
+    }
+    auto signer = members[myIdx];
+
+    CDummyContribution qc;
+    qc.llmqType = (uint8_t)llmqType;
+    qc.quorumHash = quorumHash;
+    qc.signer = (uint16_t)myIdx;
+    qc.sig = activeMasternodeInfo.blsKeyOperator->Sign(qc.GetSignHash());
+
+    ProcessDummyContribution(-1, qc);
+}
+
 void CDummyDKG::CreateDummyCommitment(Consensus::LLMQType llmqType, const CBlockIndex* pindex)
 {
     const auto& params = Params().GetConsensus().llmqs.at(llmqType);
@@ -254,6 +387,9 @@ void CDummyDKG::CreateDummyCommitment(Consensus::LLMQType llmqType, const CBlock
     auto vvec = BuildVvec(svec);
     auto vvecHash = ::SerializeHash(vvec);
     auto validMembers = GetValidMembers(llmqType, members);
+    if (std::count(validMembers.begin(), validMembers.end(), true) < params.minSize) {
+        return;
+    }
 
     auto commitmentHash = CLLMQUtils::BuildCommitmentHash((uint8_t)llmqType, quorumHash, validMembers, vvec[0], vvecHash);
 
@@ -356,9 +492,8 @@ void CDummyDKG::CreateFinalCommitment(Consensus::LLMQType llmqType, const CBlock
         quorumBlockProcessor->AddMinableCommitment(fqc);
     }
 
-    prevSessions[llmqType].badMembers = curSessions[llmqType].badMembers;
-    prevSessions[llmqType].dummyCommitments = std::move(curSessions[llmqType].dummyCommitments);
-    prevSessions[llmqType].dummyCommitmentsFromMembers = std::move(curSessions[llmqType].dummyCommitmentsFromMembers);
+    // reset for next round
+    curSessions[llmqType] = CDummyDKGSession();
 }
 
 std::vector<bool> CDummyDKG::GetValidMembers(Consensus::LLMQType llmqType, const std::vector<CDeterministicMNCPtr>& members)
@@ -368,20 +503,14 @@ std::vector<bool> CDummyDKG::GetValidMembers(Consensus::LLMQType llmqType, const
 
     LOCK(sessionCs);
 
-    // Valid members are members that sent us a dummy commitment in the previous session
+    // Valid members are members that sent us a dummy contribution in this session
 
     for (size_t i = 0; i < params.size; i++) {
-        if (!prevSessions[llmqType].badMembers.count(members[i]->proTxHash)) {
+        if (curSessions[llmqType].dummyContributionsFromMembers.count(members[i]->proTxHash)) {
             ret[i] = true;
         }
     }
 
-    // set all to valid if last sessions failed (this reboots everything)
-    if (std::count(ret.begin(), ret.end(), true) < params.minSize) {
-        for (size_t i = 0; i < params.size; i++) {
-            ret[i] = true;
-        }
-    }
     return ret;
 }
 
@@ -426,6 +555,31 @@ BLSPublicKeyVector CDummyDKG::BuildVvec(const BLSSecretKeyVector& svec)
     return vvec;
 }
 
+bool CDummyDKG::HasDummyContribution(const uint256& hash)
+{
+    LOCK(sessionCs);
+    for (const auto& p : curSessions) {
+        auto it = p.second.dummyContributions.find(hash);
+        if (it != p.second.dummyContributions.end()) {
+            return true;
+        }
+    }
+    return false;
+}
+
+bool CDummyDKG::GetDummyContribution(const uint256& hash, CDummyContribution& ret)
+{
+    LOCK(sessionCs);
+    for (const auto& p : curSessions) {
+        auto it = p.second.dummyContributions.find(hash);
+        if (it != p.second.dummyContributions.end()) {
+            ret = it->second;
+            return true;
+        }
+    }
+    return false;
+}
+
 bool CDummyDKG::HasDummyCommitment(const uint256& hash)
 {
     LOCK(sessionCs);

src/llmq/quorums_dummydkg.h

@@ -43,6 +43,38 @@ class CConnman;
 namespace llmq
 {
 
+// This is more like a PING than a contribution
+// We will later replace this message (reusing same inv type) for the real contribution
+// Deserialization will then be incompatible between peers, but that is fine (let them reject the messages)
+class CDummyContribution
+{
+public:
+    uint8_t llmqType{Consensus::LLMQ_NONE};
+    uint256 quorumHash;
+    uint16_t signer{(uint16_t)-1};
+
+    CBLSSignature sig;
+
+public:
+    ADD_SERIALIZE_METHODS
+
+    template<typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action)
+    {
+        READWRITE(llmqType);
+        READWRITE(quorumHash);
+        READWRITE(signer);
+        READWRITE(sig);
+    }
+
+    uint256 GetSignHash() const
+    {
+        CDummyContribution tmp(*this);
+        tmp.sig = CBLSSignature();
+        return ::SerializeHash(tmp);
+    }
+};
+
 // This message is only allowed on testnet/devnet/regtest
 // If any peer tries to send this message on mainnet, it is banned immediately
 // It is used to test commitments on testnet without actually running a full-blown DKG.
@@ -82,8 +114,9 @@ public:
 class CDummyDKGSession
 {
 public:
-    std::set<uint256> badMembers;
+    std::map<uint256, CDummyContribution> dummyContributions;
     std::map<uint256, CDummyCommitment> dummyCommitments;
+    std::map<uint256, uint256> dummyContributionsFromMembers;
     std::map<uint256, std::map<uint256, uint256>> dummyCommitmentsFromMembers;
 };
 
@@ -94,17 +127,20 @@ class CDummyDKG
 {
 private:
     CCriticalSection sessionCs;
-    std::map<Consensus::LLMQType, CDummyDKGSession> prevSessions;
     std::map<Consensus::LLMQType, CDummyDKGSession> curSessions;
 
 public:
     void ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStream& vRecv, CConnman& connman);
+    void ProcessDummyContribution(NodeId from, const CDummyContribution& qc);
     void ProcessDummyCommitment(NodeId from, const CDummyCommitment& qc);
 
     void UpdatedBlockTip(const CBlockIndex* pindex, bool fInitialDownload);
+    void CreateDummyContribution(Consensus::LLMQType llmqType, const CBlockIndex* pindex);
     void CreateDummyCommitment(Consensus::LLMQType llmqType, const CBlockIndex* pindex);
     void CreateFinalCommitment(Consensus::LLMQType llmqType, const CBlockIndex* pindex);
 
+    bool HasDummyContribution(const uint256& hash);
+    bool GetDummyContribution(const uint256& hash, CDummyContribution& ret);
     bool HasDummyCommitment(const uint256& hash);
     bool GetDummyCommitment(const uint256& hash, CDummyCommitment& ret);
 

src/net_processing.cpp

@@ -970,6 +970,8 @@ bool static AlreadyHave(const CInv& inv) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
         return llmq::quorumBlockProcessor->HasMinableCommitment(inv.hash);
     case MSG_QUORUM_DUMMY_COMMITMENT:
         return llmq::quorumDummyDKG->HasDummyCommitment(inv.hash);
+    case MSG_QUORUM_DUMMY_CONTRIBUTION:
+        return llmq::quorumDummyDKG->HasDummyContribution(inv.hash);
     }
 
     // Don't know what it is, just say we already got one
@@ -1291,6 +1293,14 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam
                     }
                 }
 
+                if (!push && (inv.type == MSG_QUORUM_DUMMY_CONTRIBUTION)) {
+                    llmq::CDummyContribution o;
+                    if (llmq::quorumDummyDKG->GetDummyContribution(inv.hash, o)) {
+                        connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::QCONTRIB, o));
+                        push = true;
+                    }
+                }
+
                 if (!push && (inv.type == MSG_QUORUM_DUMMY_COMMITMENT)) {
                     if (!consensusParams.fLLMQAllowDummyCommitments) {
                         Misbehaving(pfrom->id, 100);

src/protocol.cpp

@@ -73,6 +73,7 @@ const char *GETMNLISTDIFF="getmnlistd";
 const char *MNLISTDIFF="mnlistdiff";
 const char *QFCOMMITMENT="qfcommit";
 const char *QDCOMMITMENT="qdcommit";
+const char *QCONTRIB="qcontrib";
 };
 
 static const char* ppszTypeName[] =
@@ -102,6 +103,7 @@ static const char* ppszTypeName[] =
     "compact block", // Should never occur
     NetMsgType::QFCOMMITMENT,
     NetMsgType::QDCOMMITMENT,
+    NetMsgType::QCONTRIB,
 };
 
 /** All known message types. Keep this in the same order as the list of
@@ -163,6 +165,7 @@ const static std::string allNetMessageTypes[] = {
     NetMsgType::MNLISTDIFF,
     NetMsgType::QFCOMMITMENT,
     NetMsgType::QDCOMMITMENT,
+    NetMsgType::QCONTRIB,
 };
 const static std::vector<std::string> allNetMessageTypesVec(allNetMessageTypes, allNetMessageTypes+ARRAYLEN(allNetMessageTypes));
 

src/protocol.h

@@ -272,6 +272,7 @@ extern const char *GETMNLISTDIFF;
 extern const char *MNLISTDIFF;
 extern const char *QFCOMMITMENT;
 extern const char *QDCOMMITMENT;
+extern const char *QCONTRIB;
 };
 
 /* Get a vector of all valid message types (see above) */
@@ -375,6 +376,7 @@ enum GetDataMsg {
     MSG_CMPCT_BLOCK = 20, //!< Defined in BIP152
     MSG_QUORUM_FINAL_COMMITMENT = 21,
     MSG_QUORUM_DUMMY_COMMITMENT = 22, // only valid on testnet/devnet/regtest
+    MSG_QUORUM_DUMMY_CONTRIBUTION = 23, // not a valid contribution and only allowed on testnet/devnet/regtest. Will later be replaced with the real contribution
 };
 
 /** inv message data */