From 087f8fe84f0759e3bf1eb886615d3b9625d23f63 Mon Sep 17 00:00:00 2001
From: Travis Groth <travisgroth@users.noreply.github.com>
Date: Mon, 22 Jul 2019 18:09:37 -0400
Subject: [PATCH] Fix checksum integer overflow in metrics

---
 cmd/pomerium/main.go             |  8 +++++---
 internal/metrics/helpers_test.go | 10 +++++++++-
 internal/metrics/info.go         | 12 ++++++------
 internal/metrics/info_test.go    |  6 +++---
 4 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/cmd/pomerium/main.go b/cmd/pomerium/main.go
index 9c19ee647..4891304fe 100644
--- a/cmd/pomerium/main.go
+++ b/cmd/pomerium/main.go
@@ -213,11 +213,13 @@ func parseOptions(configFile string) (*config.Options, error) {
 	metrics.AddPolicyCountCallback(o.Services, func() int64 {
 		return int64(len(o.Policies))
 	})
-	checksumInt, err := strconv.ParseInt(fmt.Sprintf("0x%s", o.Checksum()), 0, 64)
+
+	checksumDec, err := strconv.ParseUint(o.Checksum(), 16, 64)
 	if err != nil {
-		log.Warn().Err(err).Msg("Could not parse config checksum into integer")
+		log.Warn().Err(err).Msg("Could not parse config checksum into decimal")
 	}
-	metrics.SetConfigChecksum(o.Services, checksumInt)
+	metrics.SetConfigChecksum(o.Services, checksumDec)
+
 	return o, nil
 }
 
diff --git a/internal/metrics/helpers_test.go b/internal/metrics/helpers_test.go
index 12b779318..b8f02a2e7 100644
--- a/internal/metrics/helpers_test.go
+++ b/internal/metrics/helpers_test.go
@@ -36,7 +36,15 @@ func testDataRetrieval(v *view.View, t *testing.T, want string) {
 	}
 }
 
-func testMetricRetrieval(metrics []*metricdata.Metric, t *testing.T, labels []metricdata.LabelValue, value int64, name string) {
+func testMetricRetrieval(metrics []*metricdata.Metric, t *testing.T, labels []metricdata.LabelValue, value interface{}, name string) {
+	switch value.(type) {
+	case int64:
+	case float64:
+	case uint64:
+	default:
+		t.Errorf("Got an unexpected type for value: %T", value)
+	}
+
 	found := false
 	for _, metric := range metrics {
 		if metric.Descriptor.Name != name {
diff --git a/internal/metrics/info.go b/internal/metrics/info.go
index b0c9b3355..d822e7482 100644
--- a/internal/metrics/info.go
+++ b/internal/metrics/info.go
@@ -76,7 +76,7 @@ type metricRegistry struct {
 	registry       *metric.Registry
 	buildInfo      *metric.Int64Gauge
 	policyCount    *metric.Int64DerivedGauge
-	configChecksum *metric.Int64Gauge
+	configChecksum *metric.Float64Gauge
 	sync.Once
 }
 
@@ -99,8 +99,8 @@ func (r *metricRegistry) init() {
 				log.Error().Err(err).Msg("internal/metrics: failed to register build info metric")
 			}
 
-			r.configChecksum, err = r.registry.AddInt64Gauge("config_checksum_int64",
-				metric.WithDescription("Config checksum represented in int64 notation"),
+			r.configChecksum, err = r.registry.AddFloat64Gauge("config_checksum_decimal",
+				metric.WithDescription("Config checksum represented in decimal notation"),
 				metric.WithLabelKeys("service"),
 			)
 			if err != nil {
@@ -149,7 +149,7 @@ func RegisterInfoMetrics() {
 	metricproducer.GlobalManager().AddProducer(registry.registry)
 }
 
-func (r *metricRegistry) setConfigChecksum(service string, checksum int64) {
+func (r *metricRegistry) setConfigChecksum(service string, checksum uint64) {
 	if r.configChecksum == nil {
 		return
 	}
@@ -157,12 +157,12 @@ func (r *metricRegistry) setConfigChecksum(service string, checksum int64) {
 	if err != nil {
 		log.Error().Err(err).Msg("internal/metrics: failed to get config checksum metric")
 	}
-	m.Set(checksum)
+	m.Set(float64(checksum))
 }
 
 // SetConfigChecksum creates the configuration checksum metric.  You must call RegisterInfoMetrics to
 // have this exported
-func SetConfigChecksum(service string, checksum int64) {
+func SetConfigChecksum(service string, checksum uint64) {
 	registry.setConfigChecksum(service, checksum)
 }
 
diff --git a/internal/metrics/info_test.go b/internal/metrics/info_test.go
index 50eddfc47..c29285a49 100644
--- a/internal/metrics/info_test.go
+++ b/internal/metrics/info_test.go
@@ -49,7 +49,7 @@ func Test_SetBuildInfo(t *testing.T) {
 	}
 
 	SetBuildInfo("test_service")
-	testMetricRetrieval(registry.registry.Read(), t, wantLabels, 1, "build_info")
+	testMetricRetrieval(registry.registry.Read(), t, wantLabels, int64(1), "build_info")
 }
 
 func Test_AddPolicyCountCallback(t *testing.T) {
@@ -65,11 +65,11 @@ func Test_AddPolicyCountCallback(t *testing.T) {
 func Test_SetConfigChecksum(t *testing.T) {
 	registry = newMetricRegistry()
 
-	wantValue := int64(42)
+	wantValue := uint64(42)
 	wantLabels := []metricdata.LabelValue{{Value: "test_service", Present: true}}
 	SetConfigChecksum("test_service", wantValue)
 
-	testMetricRetrieval(registry.registry.Read(), t, wantLabels, wantValue, "config_checksum_int64")
+	testMetricRetrieval(registry.registry.Read(), t, wantLabels, float64(wantValue), "config_checksum_decimal")
 }
 
 func Test_RegisterInfoMetrics(t *testing.T) {