Add check that parent ID in trace context is correct length

Author: DarcyRaynerDD

internal/trace/context.go

@@ -185,7 +185,10 @@ func convertHexIDToUint64(hexNumber string) (uint64, error) {
 
 // Converts an X-Ray entity ID (hex) to a Datadog parent id (uint64).
 func convertXRayEntityIDToAPMParentID(entityID string) (string, error) {
-	val, err := convertHexIDToUint64(entityID)
+	if len(entityID) < 16 {
+		return "0", fmt.Errorf("couldn't convert to trace id, too short")
+	}
+	val, err := convertHexIDToUint64(entityID[len(entityID)-16:])
 	if err != nil {
 		return "0", fmt.Errorf("couldn't convert entity id to trace id:  %v", err)
 	}

internal/trace/context_test.go

@@ -91,13 +91,19 @@ func TestConvertXRayTraceIDIncorrectCharacters(t *testing.T) {
 }
 
 func TestConvertXRayEntityID(t *testing.T) {
-	output, err := convertXRayEntityIDToAPMParentID("779014b90ce44db5e03875")
+	output, err := convertXRayEntityIDToAPMParentID("0b11cc4230d3e09e")
 	assert.NoError(t, err)
-	assert.Equal(t, "8615408872177552821", output)
+	assert.Equal(t, "797643193680388254", output)
 }
 
 func TestConvertXRayEntityIDInvalidFormat(t *testing.T) {
-	output, err := convertXRayEntityIDToAPMParentID(";79014b90ce44db5e03875")
+	output, err := convertXRayEntityIDToAPMParentID(";b11cc4230d3e09e")
+	assert.Error(t, err)
+	assert.Equal(t, "0", output)
+}
+
+func TestConvertXRayEntityIDTooShort(t *testing.T) {
+	output, err := convertXRayEntityIDToAPMParentID("c4230d3e09e")
 	assert.Error(t, err)
 	assert.Equal(t, "0", output)
 }