cmd/swarm: fix ethersphere/swarm#979:

update should error on manifest mistmatch

cmd/swarm/feeds.go

@@ -169,7 +169,6 @@ func feedUpdate(ctx *cli.Context) {
 		query = new(feed.Query)
 		query.User = signer.Address()
 		query.Topic = getTopic(ctx)
-
 	}
 
 	// Retrieve a feed update request
@@ -178,6 +177,11 @@ func feedUpdate(ctx *cli.Context) {
 		utils.Fatalf("Error retrieving feed status: %s", err.Error())
 	}
 
+	// Check that the provided signer matches the request to sign
+	if updateRequest.User != signer.Address() {
+		utils.Fatalf("Signer address does not match the update request")
+	}
+
 	// set the new data
 	updateRequest.SetData(data)
 

cmd/swarm/feeds_test.go

@@ -162,4 +162,37 @@ func TestCLIFeedUpdate(t *testing.T) {
 	if !bytes.Equal(data, retrieved) {
 		t.Fatalf("Received %s, expected %s", retrieved, data)
 	}
+
+	// test publishing a manifest for a different user
+	flags = []string{
+		"--bzzapi", srv.URL,
+		"--bzzaccount", pkFileName,
+		"feed", "create",
+		"--topic", topic.Hex(),
+		"--user", "0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", // different user
+	}
+
+	log.Info(fmt.Sprintf("Publishing manifest with 'swarm feed create' for a different user"))
+	cmd = runSwarm(t, flags...)
+	_, matches = cmd.ExpectRegexp(`[a-f\d]{64}`) // regex hack to extract stdout
+	cmd.ExpectExit()
+
+	manifestAddress = matches[0] // read the received feed manifest
+
+	// now let's try to update that user's manifest which we don't have the private key for
+	flags = []string{
+		"--bzzapi", srv.URL,
+		"--bzzaccount", pkFileName,
+		"feed", "update",
+		"--manifest", manifestAddress,
+		hexData}
+
+	// create an update and expect an exit without errors
+	log.Info(fmt.Sprintf("updating a feed with 'swarm feed update'"))
+	cmd = runSwarm(t, flags...)
+	cmd.ExpectRegexp("Fatal:.*") // best way so far to detect a failure.
+	cmd.ExpectExit()
+	if cmd.ExitStatus() == 0 {
+		t.Fatal("Expected nonzero exit code when updating a manifest with the wrong user. Got 0.")
+	}
 }