From 8950d4ed35cae655d9f2b051e7688be34b72c1a2 Mon Sep 17 00:00:00 2001
From: Al Cutter <al@google.com>
Date: Thu, 7 Mar 2024 17:35:12 +0000
Subject: [PATCH] Fix nil ptr (#128)
---
cmd/internal/distributor/distributor.go | 6 ++-
cmd/internal/distributor/distributor_test.go | 52 ++++++++++++++++++++
2 files changed, 57 insertions(+), 1 deletion(-)
diff --git a/cmd/internal/distributor/distributor.go b/cmd/internal/distributor/distributor.go
index fd757b2..bb19b41 100644
--- a/cmd/internal/distributor/distributor.go
+++ b/cmd/internal/distributor/distributor.go
@@ -251,7 +251,11 @@ func (d *Distributor) Distribute(ctx context.Context, logID, witID string, nextR
return status.Errorf(codes.Internal, "failed to scan rows: %v", err)
}
allCheckpoints = append(allCheckpoints, cp)
- witnesses = append(witnesses, d.ws[witID])
+ // If there is no known witness ID, this is probably due to an old witness
+ // having been removed from the config.
+ if w, ok := d.ws[witID]; ok {
+ witnesses = append(witnesses, w)
+ }
}
if err := rows.Err(); err != nil {
diff --git a/cmd/internal/distributor/distributor_test.go b/cmd/internal/distributor/distributor_test.go
index 53205dd..c8059eb 100644
--- a/cmd/internal/distributor/distributor_test.go
+++ b/cmd/internal/distributor/distributor_test.go
@@ -554,6 +554,58 @@ func TestFiltersUnknownSignatures(t *testing.T) {
}
}
+func TestDisappearingWitness(t *testing.T) {
+ ws := map[string]note.Verifier{
+ aardvarkVKey: witAardvark.verifier,
+ badgerVKey: witBadger.verifier,
+ }
+ ls := map[string]config.LogInfo{
+ "FooLog": logFoo.LogInfo,
+ }
+
+ ctx, cancel := context.WithCancel(context.Background())
+ defer cancel()
+ db, err := helper.create("TestDisappearingWitness")
+ if err != nil {
+ t.Fatalf("helper.create(): %v", err)
+ }
+
+ // Put a checkpoint in sigs from a known witness.
+ {
+ d, err := distributor.NewDistributor(ws, ls, db)
+ if err != nil {
+ t.Fatalf("NewDistributor(): %v", err)
+ }
+
+ writeCP := logFoo.checkpoint(16, "16", witAardvark.signer)
+ err = d.Distribute(ctx, "FooLog", "Aardvark", writeCP)
+ if err != nil {
+ t.Fatalf("Distribute(): %v", err)
+ }
+ }
+
+ // Now remove one of the witnesses; it was a bad aardvark.
+ ws = map[string]note.Verifier{
+ badgerVKey: witBadger.verifier,
+ chameleonVKey: witChameleon.verifier,
+ }
+
+ // Now recreate the distributor instance to represent re-deploying after the config update, and
+ // try to update the checkpoint with a new signature from another known witness.
+ {
+ d, err := distributor.NewDistributor(ws, ls, db)
+ if err != nil {
+ t.Fatalf("NewDistributor(): %v", err)
+ }
+
+ writeCP := logFoo.checkpoint(16, "16", witBadger.signer)
+ err = d.Distribute(ctx, "FooLog", "Badger", writeCP)
+ if err != nil {
+ t.Fatalf("Distribute(): %v", err)
+ }
+ }
+}
+
func TestGetCheckpointN(t *testing.T) {
// The base case for this test is that 2 checkpoints have already been written:
// - aardvark, at tree size 16