From 4fad8e6d831729efa1965fa2034e7e51d3d0a1be Mon Sep 17 00:00:00 2001 From: Peter Todd Date: Thu, 8 May 2014 00:18:57 -0400 Subject: [PATCH] Reject transactions with excessive numbers of sigops --- 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 a9c080ffaee..490b7f56feb 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -1016,9 +1016,18 @@ 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 f6bac889beb..547e7305ead 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 */