diff options
Diffstat (limited to 'src/main.cpp')
| -rw-r--r-- | src/main.cpp | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/src/main.cpp b/src/main.cpp index d945ece417..0b36b5f219 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -4041,7 +4041,12 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, } - else if (strCommand == "getaddr") + // This asymmetric behavior for inbound and outbound connections was introduced + // to prevent a fingerprinting attack: an attacker can send specific fake addresses + // to users' AddrMan and later request them by sending getaddr messages. + // Making users (which are behind NAT and can only make outgoing connections) ignore + // getaddr message mitigates the attack. + else if ((strCommand == "getaddr") && (pfrom->fInbound)) { pfrom->vAddrToSend.clear(); vector<CAddress> vAddr = addrman.GetAddr(); @@ -4325,7 +4330,7 @@ bool ProcessMessages(CNode* pfrom) // Read header CMessageHeader& hdr = msg.hdr; - if (!hdr.IsValid()) + if (!hdr.IsValid(Params().MessageStart())) { LogPrintf("PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n", SanitizeString(hdr.GetCommand()), pfrom->id); continue; @@ -4338,8 +4343,7 @@ bool ProcessMessages(CNode* pfrom) // Checksum CDataStream& vRecv = msg.vRecv; uint256 hash = Hash(vRecv.begin(), vRecv.begin() + nMessageSize); - unsigned int nChecksum = 0; - memcpy(&nChecksum, &hash, sizeof(nChecksum)); + unsigned int nChecksum = ReadLE32((unsigned char*)&hash); if (nChecksum != hdr.nChecksum) { LogPrintf("ProcessMessages(%s, %u bytes): CHECKSUM ERROR nChecksum=%08x hdr.nChecksum=%08x\n", |