diff options
Diffstat (limited to 'eth/downloader/downloader_test.go')
| -rw-r--r-- | eth/downloader/downloader_test.go | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/eth/downloader/downloader_test.go b/eth/downloader/downloader_test.go index f71c16237..53eb5f81d 100644 --- a/eth/downloader/downloader_test.go +++ b/eth/downloader/downloader_test.go @@ -708,6 +708,40 @@ func TestBannedChainMemoryExhaustionAttack(t *testing.T) { } } +// Tests a corner case (potential attack) where a peer delivers both good as well +// as unrequested blocks to a hash request. This may trigger a different code +// path than the fully correct or fully invalid delivery, potentially causing +// internal state problems +// +// No, don't delete this test, it actually did happen! +func TestOverlappingDeliveryAttack(t *testing.T) { + // Create an arbitrary batch of blocks ( < cache-size not to block) + targetBlocks := blockCacheLimit - 23 + hashes := createHashes(targetBlocks, knownHash) + blocks := createBlocksFromHashes(hashes) + + // Register an attacker that always returns non-requested blocks too + tester := newTester() + tester.newPeer("attack", hashes, blocks) + + rawGetBlocks := tester.downloader.peers.Peer("attack").getBlocks + tester.downloader.peers.Peer("attack").getBlocks = func(request []common.Hash) error { + // Add a non requested hash the screw the delivery (genesis should be fine) + return rawGetBlocks(append(request, hashes[0])) + } + // Test that synchronisation can complete, check for import success + if err := tester.sync("attack"); err != nil { + t.Fatalf("failed to synchronise blocks: %v", err) + } + start := time.Now() + for len(tester.ownHashes) != len(hashes) && time.Since(start) < time.Second { + time.Sleep(50 * time.Millisecond) + } + if len(tester.ownHashes) != len(hashes) { + t.Fatalf("chain length mismatch: have %v, want %v", len(tester.ownHashes), len(hashes)) + } +} + // Tests that misbehaving peers are disconnected, whilst behaving ones are not. func TestHashAttackerDropping(t *testing.T) { // Define the disconnection requirement for individual hash fetch errors |