From 9f5cc03f94de86c2e89d7e4f1d403752ec48bb10 Mon Sep 17 00:00:00 2001
From: Gregory Sanders <gsanders87@gmail.com>
Date: Mon, 17 Dec 2018 11:39:54 -0500
Subject: [PATCH] Read PAK list from connected blocks, save list, and boot
 transactions not conforming

---
 src/txmempool.cpp  | 23 +++++++++++++++++++++--
 src/txmempool.h    |  2 +-
 src/validation.cpp | 17 ++++++++++++++++-
 3 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index f9dd8488c7..b125c37ed2 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -17,6 +17,7 @@
 #include <util.h>
 #include <utilmoneystr.h>
 #include <utiltime.h>
+#include <chainparams.h> // removeForBlock paklist transition
 
 CTxMemPoolEntry::CTxMemPoolEntry(const CTransactionRef& _tx, const CAmount& _nFee,
                                  int64_t _nTime, unsigned int _entryHeight,
@@ -569,7 +570,7 @@ void CTxMemPool::removeConflicts(const CTransaction &tx)
 /**
  * Called when a block is connected. Removes from mempool and updates the miner fee estimator.
  */
-void CTxMemPool::removeForBlock(const std::vector<CTransactionRef>& vtx, unsigned int nBlockHeight, const std::set<std::pair<uint256, COutPoint>>& setPeginsSpent)
+void CTxMemPool::removeForBlock(const std::vector<CTransactionRef>& vtx, unsigned int nBlockHeight, const std::set<std::pair<uint256, COutPoint>>& setPeginsSpent, bool pak_transition)
 {
     LOCK(cs);
     std::vector<const CTxMemPoolEntry*> entries;
@@ -611,7 +612,25 @@ void CTxMemPool::removeForBlock(const std::vector<CTransactionRef>& vtx, unsigne
             ClearPrioritisation(tx_id);
         }
     }
-
+    // Eject any newly-invalid peg-outs based on changing block commitment
+    const CChainParams& chainparams = Params();
+    if (pak_transition && !gArgs.GetBoolArg("-acceptnonstdtxn", !chainparams.RequireStandard())) {
+        for (const auto& entry : mapTx) {
+            for (const auto& out : entry.GetTx().vout) {
+                if (out.scriptPubKey.IsPegoutScript(Params().ParentGenesisBlockHash()) &&
+                            !ScriptHasValidPAKProof(out.scriptPubKey, Params().ParentGenesisBlockHash())) {
+                    txiter it = mapTx.find(entry.GetTx().GetHash());
+                    const CTransaction& tx = it->GetTx();
+                    setEntries stage;
+                    stage.insert(it);
+                    RemoveStaged(stage, true, MemPoolRemovalReason::BLOCK);
+                    removeRecursive(tx, MemPoolRemovalReason::BLOCK);
+                    ClearPrioritisation(tx.GetHash());
+                    break;
+                }
+            }
+        }
+    }
     lastRollingFeeUpdate = GetTime();
     blockSinceLastRollingFeeBump = true;
 }
diff --git a/src/txmempool.h b/src/txmempool.h
index adad69b6c9..1352188fd6 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -552,7 +552,7 @@ public:
     void removeForReorg(const CCoinsViewCache *pcoins, unsigned int nMemPoolHeight, int flags);
     void removeConflicts(const CTransaction &tx) EXCLUSIVE_LOCKS_REQUIRED(cs);
     void removeForBlock(const std::vector<CTransactionRef>& vtx, unsigned int nBlockHeight,
-                        const std::set<std::pair<uint256, COutPoint>>& setPeginsSpent);
+                        const std::set<std::pair<uint256, COutPoint>>& setPeginsSpent, bool pak_transition=false);
 
     void clear();
     void _clear() EXCLUSIVE_LOCKS_REQUIRED(cs); //lock free
diff --git a/src/validation.cpp b/src/validation.cpp
index 83b369ba65..31589d395c 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -2585,10 +2585,25 @@ bool CChainState::ConnectTip(CValidationState& state, const CChainParams& chainp
     // Write the chain state to disk, if necessary.
     if (!FlushStateToDisk(chainparams, state, FlushStateMode::IF_NEEDED))
         return false;
+
+    // Get PAK commitment from coinbase, if it exists
+    boost::optional<CPAKList> paklist = GetPAKKeysFromCommitment(*blockConnecting.vtx[0]);
+    if (paklist) {
+        std::vector<std::vector<unsigned char> > offline_keys;
+        std::vector<std::vector<unsigned char> > online_keys;
+        bool is_reject;
+        paklist->ToBytes(offline_keys, online_keys, is_reject);
+        pblocktree->WritePAKList(offline_keys, online_keys, is_reject);
+        g_paklist_blockchain = *paklist;
+    }
+
     int64_t nTime5 = GetTimeMicros(); nTimeChainState += nTime5 - nTime4;
     LogPrint(BCLog::BENCH, "  - Writing chainstate: %.2fms [%.2fs (%.2fms/blk)]\n", (nTime5 - nTime4) * MILLI, nTimeChainState * MICRO, nTimeChainState * MILLI / nBlocksTotal);
     // Remove conflicting transactions from the mempool.;
-    mempool.removeForBlock(blockConnecting.vtx, pindexNew->nHeight, setPeginsSpent);
+    // ELEMENTS: We also eject now-invalid peg-outs based on block transition if not config list set
+    // If config is set, this means all peg-outs have been filtered for that list already and other
+    // functionaries aren't matching your list. Operator should restart with no list or new matching list.
+    mempool.removeForBlock(blockConnecting.vtx, pindexNew->nHeight, setPeginsSpent, (paklist && !g_paklist_config));
     disconnectpool.removeForBlock(blockConnecting.vtx);
     // Update chainActive & related variables.
     chainActive.SetTip(pindexNew);