From a68ec21f7ed2978d8945a0f4cfd7e80bfa5fd917 Mon Sep 17 00:00:00 2001 From: Pieter Wuille Date: Fri, 6 May 2016 21:53:38 +0200 Subject: [PATCH] Use SipHash-2-4 for address relay selection --- src/main.cpp | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) diff --git a/src/main.cpp b/src/main.cpp index 09f82312a9..a1c027bef3 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -4698,25 +4698,23 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, LOCK(cs_vNodes); // Use deterministic randomness to send to the same nodes for 24 hours // at a time so the addrKnowns of the chosen nodes prevent repeats - static uint256 hashSalt; - if (hashSalt.IsNull()) - hashSalt = GetRandHash(); + static uint64_t salt0 = 0, salt1 = 0; + while (salt0 == 0 && salt1 == 0) { + GetRandBytes((unsigned char*)&salt0, sizeof(salt0)); + GetRandBytes((unsigned char*)&salt1, sizeof(salt1)); + } uint64_t hashAddr = addr.GetHash(); - uint256 hashRand = ArithToUint256(UintToArith256(hashSalt) ^ (hashAddr<<32) ^ ((GetTime()+hashAddr)/(24*60*60))); - hashRand = Hash(BEGIN(hashRand), END(hashRand)); - multimap mapMix; + multimap mapMix; + const CSipHasher hasher = CSipHasher(salt0, salt1).Write(hashAddr << 32).Write((GetTime() + hashAddr) / (24*60*60)); BOOST_FOREACH(CNode* pnode, vNodes) { if (pnode->nVersion < CADDR_TIME_VERSION) continue; - unsigned int nPointer; - memcpy(&nPointer, &pnode, sizeof(nPointer)); - uint256 hashKey = ArithToUint256(UintToArith256(hashRand) ^ nPointer); - hashKey = Hash(BEGIN(hashKey), END(hashKey)); + uint64_t hashKey = CSipHasher(hasher).Write(pnode->id).Finalize(); mapMix.insert(make_pair(hashKey, pnode)); } int nRelayNodes = fReachable ? 2 : 1; // limited relaying of addresses outside our network(s) - for (multimap::iterator mi = mapMix.begin(); mi != mapMix.end() && nRelayNodes-- > 0; ++mi) + for (multimap::iterator mi = mapMix.begin(); mi != mapMix.end() && nRelayNodes-- > 0; ++mi) ((*mi).second)->PushAddress(addr); } }