From 9ee09dc64fbe712401c57b458c8254a1fdaaa5f2 Mon Sep 17 00:00:00 2001
From: Peter Todd <pete@petertodd.org>
Date: Thu, 8 May 2014 00:18:57 -0400
Subject: [PATCH] Reapply: Reject transactions with excessive numbers of sigops
Reverting was based on a misunderstanding, it appears.
Github-Pull: #4150
---
src/main.cpp | 15 ++++++++++++---
src/main.h | 2 ++
2 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/src/main.cpp b/src/main.cpp
index 55206600e..e135e93ad 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -956,9 +956,18 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
if (Params().RequireStandard() && !AreInputsStandard(tx, view))
return error("AcceptToMemoryPool: : nonstandard transaction input");
- // Note: if you modify this code to accept non-standard transactions, then
- // you should add code here to check that the transaction does a
- // reasonable number of ECDSA signature verifications.
+ // Check that the transaction doesn't have an excessive number of
+ // sigops, making it impossible to mine. Since the coinbase transaction
+ // itself can contain sigops MAX_TX_SIGOPS is less than
+ // MAX_BLOCK_SIGOPS; we still consider this an invalid rather than
+ // merely non-standard transaction.
+ unsigned int nSigOps = GetLegacySigOpCount(tx);
+ nSigOps += GetP2SHSigOpCount(tx, view);
+ if (nSigOps > MAX_TX_SIGOPS)
+ return state.DoS(0,
+ error("AcceptToMemoryPool : too many sigops %s, %d > %d",
+ hash.ToString(), nSigOps, MAX_TX_SIGOPS),
+ REJECT_NONSTANDARD, "bad-txns-too-many-sigops");
int64_t nValueOut = tx.GetValueOut();
int64_t nFees = nValueIn-nValueOut;
diff --git a/src/main.h b/src/main.h
index a27020459..01d3f119e 100644
--- a/src/main.h
+++ b/src/main.h
@@ -45,6 +45,8 @@ static const unsigned int MAX_STANDARD_TX_SIZE = 100000;
static const unsigned int MAX_BLOCK_SIGOPS = MAX_BLOCK_SIZE/50;
/** Maxiumum number of signature check operations in an IsStandard() P2SH script */
static const unsigned int MAX_P2SH_SIGOPS = 15;
+/** The maximum number of sigops we're willing to relay/mine in a single tx */
+static const unsigned int MAX_TX_SIGOPS = MAX_BLOCK_SIGOPS/5;
/** The maximum number of orphan transactions kept in memory */
static const unsigned int MAX_ORPHAN_TRANSACTIONS = MAX_BLOCK_SIZE/100;
/** Default for -maxorphanblocks, maximum number of orphan blocks kept in memory */