preventing DoS attacks using invalid proposals

.gitignore

@@ -47,60 +47,14 @@ src/qt/.deps
 src/qt/.dirstamp
 src/qt/bitcoin.moc
 src/qt/bitcoinamountfield.moc
-src/qt/moc_aboutdialog.cpp
-src/qt/moc_addressbookpage.cpp
-src/qt/moc_addresstablemodel.cpp
-src/qt/moc_askpassphrasedialog.cpp
-src/qt/moc_bip38tooldialog.cpp
-src/qt/moc_bitcoinaddressvalidator.cpp
-src/qt/moc_bitcoinamountfield.cpp
-src/qt/moc_bitcoingui.cpp
-src/qt/moc_bitcoinunits.cpp
-src/qt/moc_clientmodel.cpp
-src/qt/moc_coincontroldialog.cpp
-src/qt/moc_coincontroltreewidget.cpp
-src/qt/moc_csvmodelwriter.cpp
-src/qt/moc_editaddressdialog.cpp
-src/qt/moc_guiutil.cpp
-src/qt/moc_macdockiconhandler.cpp
-src/qt/moc_monitoreddatamapper.cpp
-src/qt/moc_notificator.cpp
-src/qt/moc_optionsdialog.cpp
-src/qt/moc_optionsmodel.cpp
-src/qt/moc_overviewpage.cpp
-src/qt/moc_qrcodedialog.cpp
-src/qt/moc_qvalidatedlineedit.cpp
-src/qt/moc_qvaluecombobox.cpp
-src/qt/moc_rpcconsole.cpp
-src/qt/moc_sendcoinsdialog.cpp
-src/qt/moc_sendcoinsentry.cpp
-src/qt/moc_signverifymessagedialog.cpp
-src/qt/moc_transactiondesc.cpp
-src/qt/moc_transactiondescdialog.cpp
-src/qt/moc_transactionfilterproxy.cpp
-src/qt/moc_transactiontablemodel.cpp
-src/qt/moc_transactionview.cpp
-src/qt/moc_walletmodel.cpp
+src/qt/moc_*
 src/qt/overviewpage.moc
 src/qt/rpcconsole.moc
 Makefile.in
 src/config/bitcoin-config.h
 src/config/bitcoin-config.h.in
 src/config/stamp-h1
-src/qt/forms/ui_aboutdialog.h
-src/qt/forms/ui_addressbookpage.h
-src/qt/forms/ui_askpassphrasedialog.h
-src/qt/forms/ui_bip38tooldialog.h
-src/qt/forms/ui_coincontroldialog.h
-src/qt/forms/ui_editaddressdialog.h
-src/qt/forms/ui_optionsdialog.h
-src/qt/forms/ui_overviewpage.h
-src/qt/forms/ui_qrcodedialog.h
-src/qt/forms/ui_rpcconsole.h
-src/qt/forms/ui_sendcoinsdialog.h
-src/qt/forms/ui_sendcoinsentry.h
-src/qt/forms/ui_signverifymessagedialog.h
-src/qt/forms/ui_transactiondescdialog.h
+src/qt/forms/ui_*
 config.log
 config.status
 libtool

src/main.cpp

@@ -711,6 +711,17 @@ bool CTxMemPool::accept(CTxDB& txdb, CTransaction &tx, bool fCheckInputs,
     if (ptxOld)
         EraseFromWallets(ptxOld->GetHash());
 
+    // If the transaction is a proposal then verify validity
+    if (tx.IsProposal()) {
+        CVoteProposal proposal;
+        ProposalFromTransaction(tx, proposal);
+
+        // Verify that the proposal is valid
+        if(!proposalManager.CheckProposal(proposal)) {
+            return error("CTxMemPool::accept() : Invalid Proposal %s", hash.ToString().substr(0,10).c_str());
+        }
+    }
+
     printf("CTxMemPool::accept() : accepted %s (poolsz %lu)\n",
            hash.ToString().substr(0,10).c_str(),
            mapTx.size());

src/voteproposalmanager.cpp

@@ -7,6 +7,42 @@
 
 using namespace std;
 
+bool CVoteProposalManager::CheckProposal(const CVoteProposal &proposal)
+{
+    // If the proposal is already in the blockchain then it's guaranteed to be valid
+    if (mapProposalData.count(proposal.GetHash()) != 0) {
+        return true;
+    }
+
+    // Proposal name length must be between 1 and MAX_CHAR_NAME (inclusive)
+    if (proposal.GetName().empty() || proposal.GetName().size() > MAX_CHAR_NAME) {
+        return false;
+    }
+
+    // Proposal description length must be between 1 and MAX_CHAR_ABSTRACT (inclusive)
+    if (proposal.GetDescription().empty() || proposal.GetDescription().size() > MAX_CHAR_ABSTRACT) {
+        return false;
+    }
+
+    // Proposal voting period cannot start before or at the current height or after MAX_BLOCKS_IN_FUTURE
+    if (proposal.GetStartHeight() <= nBestHeight || proposal.GetStartHeight() > nBestHeight + MAX_BLOCKS_IN_FUTURE) {
+        return false;
+    }
+
+    // Proposal voting period length must be between 1 and MAX_CHECKSPAN (inclusive)
+    if (!proposal.GetCheckSpan() || proposal.GetCheckSpan() > MAX_CHECKSPAN) {
+        return false;
+    }
+
+    // Check to see if there is room on the blockchain for this proposal
+    VoteLocation location;
+    if (!GetNextLocation(proposal.GetBitCount(), proposal.GetStartHeight(), proposal.GetCheckSpan(), location)) {
+        return false;
+    }
+
+    return true;
+}
+
 //! Add a proposal to the manager. Note that it must not have conflicts in its scheduling.
 bool CVoteProposalManager::Add(const CVoteProposal& proposal)
 {

src/voteproposalmanager.h

@@ -28,6 +28,7 @@ class CVoteProposalManager
     std::map<uint256, VoteLocation> GetActive(int nHeight);
     bool GetNextLocation(int nBitCount, int nStartHeight, int nCheckSpan, VoteLocation& location);
     std::map<uint256, CProposalMetaData> GetAllProposals() const { return mapProposalData; };
+    bool CheckProposal (const CVoteProposal& proposal);
 };
 
 #endif //HYPERSTAKE_VOTEPROPOSALMANAGER_H