mixpool: Reject KEs submitted too early

decred · Jul 8, 2024 · f16f4f2 · f16f4f2
1 parent 02a286d
commit f16f4f2
Show file tree

Hide file tree

Showing 3 changed files with 12 additions and 2 deletions.
diff --git a/mixing/mixpool/mixpool.go b/mixing/mixpool/mixpool.go
@@ -28,6 +28,7 @@ import (
 
 const minconf = 1
 const feeRate = 0.0001e8
+const earlyKEDuration = 5 * time.Second
 
 type idPubKey = [33]byte
 
@@ -1394,6 +1395,13 @@ func (p *Pool) checkAcceptKE(ke *wire.MsgMixKeyExchange) error {
 		return ruleError(ErrPeerPositionOutOfBounds)
 	}
 
+	now := time.Now()
+	keEpoch := time.Unix(int64(ke.Epoch), 0)
+	if now.Before(keEpoch) && keEpoch.Sub(now) > earlyKEDuration {
+		err := fmt.Errorf("KE received too early for stated epoch")
+		return ruleError(err)
+	}
+
 	return nil
 }
 

diff --git a/mixing/mixpool/mixpool_test.go b/mixing/mixpool/mixpool_test.go
@@ -14,6 +14,7 @@ import (
 	"math/big"
 	"os"
 	"testing"
+	"time"
 
 	"decred.org/cspp/v2/solverrpc"
 	"github.com/davecgh/go-spew/spew"
@@ -255,7 +256,7 @@ func TestAccept(t *testing.T) {
 
 	var (
 		seenPRs               = []chainhash.Hash{pr.Hash()}
-		epoch      uint64     = 0
+		epoch      uint64     = uint64(time.Now().Unix())
 		sid        [32]byte   = mixing.SortPRsForSession([]*wire.MsgMixPairReq{pr}, epoch)
 		run        uint32     = 0
 		pos        uint32     = 0

diff --git a/mixing/mixpool/orphans_test.go b/mixing/mixpool/orphans_test.go
@@ -8,6 +8,7 @@ import (
 	"errors"
 	"reflect"
 	"testing"
+	"time"
 
 	"github.com/decred/dcrd/chaincfg/chainhash"
 	"github.com/decred/dcrd/chaincfg/v3"
@@ -65,7 +66,7 @@ func TestOrphans(t *testing.T) {
 	pr.WriteHash(h)
 
 	prs := []*wire.MsgMixPairReq{pr}
-	epoch := uint64(1704067200)
+	epoch := uint64(time.Now().Unix())
 	sid := mixing.SortPRsForSession(prs, epoch)
 	ke := &wire.MsgMixKeyExchange{
 		Identity: id,