lower time check, make bannable

mixing/mixpool/errors.go

@@ -91,6 +91,10 @@ var (
 	// position of a peer's own PR is outside of the possible bounds of
 	// the previously seen messages.
 	ErrPeerPositionOutOfBounds = newBannableError("peer position cannot be a valid seen PRs index", 0)
+
+	// ErrEarlyKE is returned by AcceptMessage if a key exchange message
+	// with a stated epoch is sent too early for that epoch time.
+	ErrEarlyKE = newBannableError("KE received too early for stated epoch", 0)
 )
 
 // IsBannable returns whether the error condition is such that the peer with

mixing/mixpool/mixpool.go

@@ -28,7 +28,7 @@ import (
 
 const minconf = 1
 const feeRate = 0.0001e8
-const clientTimeoutDuration = 30 * time.Second
+const earlyKEDuration = 5 * time.Second
 
 type idPubKey = [33]byte
 
@@ -1396,8 +1396,7 @@ func (p *Pool) checkAcceptKE(ke *wire.MsgMixKeyExchange) error {
 	}
 
 	keEpoch := time.Unix(int64(ke.Epoch), 0)
-	if keEpoch.Add(clientTimeoutDuration).Before(time.Now()) {
-		err := fmt.Errorf("KE received too early for stated epoch")
+	if keEpoch.Add(earlyKEDuration).Before(time.Now()) {
 		return ruleError(err)
 	}