Merge pull request #5918

f7303f9 Use equivalent PoW for non-main-chain requests (Pieter Wuille)

1 files changed, 5 insertions, 4 deletions

diff --git a/src/main.cpp b/src/main.cpp
index 2c12e0849..e6248c661 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3675,7 +3675,6 @@ bool static AlreadyHave(const CInv& inv)
     return true;
 }
 
-
 void static ProcessGetData(CNode* pfrom)
 {
     std::deque<CInv>::iterator it = pfrom->vRecvGetData.begin();
@@ -3703,11 +3702,13 @@ void static ProcessGetData(CNode* pfrom)
                     if (chainActive.Contains(mi->second)) {
                         send = true;
                     } else {
+                        static const int nOneMonth = 30 * 24 * 60 * 60;
                         // To prevent fingerprinting attacks, only send blocks outside of the active
-                        // chain if they are valid, and no more than a month older than the best header
-                        // chain we know about.
+                        // chain if they are valid, and no more than a month older (both in time, and in
+                        // best equivalent proof of work) than the best header chain we know about.
                         send = mi->second->IsValid(BLOCK_VALID_SCRIPTS) && (pindexBestHeader != NULL) &&
-                            (mi->second->GetBlockTime() > pindexBestHeader->GetBlockTime() - 30 * 24 * 60 * 60);
+                            (pindexBestHeader->GetBlockTime() - mi->second->GetBlockTime() < nOneMonth) &&
+                            (GetBlockProofEquivalentTime(*pindexBestHeader, *mi->second, *pindexBestHeader, Params().GetConsensus()) < nOneMonth);
                         if (!send) {
                             LogPrintf("%s: ignoring request from peer=%i for old block that isn't in the main chain\n", __func__, pfrom->GetId());
                         }