From db9f2e011732d5c04728196e29e0f0a029a8ea4d Mon Sep 17 00:00:00 2001 From: Pieter Wuille Date: Sat, 25 Feb 2012 19:02:30 +0100 Subject: [PATCH] Do not invoke anti-DoS system for invalid BIP16 transactions Doing so would allow an attack on old nodes, which would relay a standard transaction spending a BIP16 output in an invalid way, until reaching a new node, which will disconnect their peer. Reported by makomk on IRC. --- src/main.cpp | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/src/main.cpp b/src/main.cpp index a9311e2c..e80ecaa0 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -1138,7 +1138,14 @@ bool CTransaction::ConnectInputs(MapPrevTx inputs, { // Verify signature if (!VerifySignature(txPrev, *this, i, fStrictPayToScriptHash, 0)) + { + // only during transition phase for P2SH: do not invoke anti-DoS code for + // potentially old clients relaying bad P2SH transactions + if (fStrictPayToScriptHash && VerifySignature(txPrev, *this, i, false, 0)) + return error("ConnectInputs() : %s P2SH VerifySignature failed", GetHash().ToString().substr(0,10).c_str()); + return DoS(100,error("ConnectInputs() : %s VerifySignature failed", GetHash().ToString().substr(0,10).c_str())); + } } // Mark outpoints as spent