NitrokeyManager: Also return serial number as u32

This patch adds the get_serial_number_as_u32 method to NitrokeyManager.
It returns the serial number as a 32-bit unsigned integer.  Previously,
we only returned it as a string generated from the integer value,
get_serial_number.

While get_serial_number returns an empty string if no device is
connected and "NA" if an unknown model is connected, the new method
throws a DeviceNotConnected exception in the first case and returns zero
in the second case as we cannot express the three states in one integer
return value.

3 files changed, 24 insertions, 0 deletions

diff --git a/NitrokeyManager.cc b/NitrokeyManager.cc
index 6c26a43..496496e 100644
--- a/NitrokeyManager.cc
+++ b/NitrokeyManager.cc
@@ -398,6 +398,25 @@ using nitrokey::misc::strcpyT;
       return "NA";
     }
 
+    uint32_t NitrokeyManager::get_serial_number_as_u32() {
+        if (device == nullptr) { throw DeviceNotConnected("device not connected"); }
+      switch (device->get_device_model()) {
+        case DeviceModel::PRO: {
+          auto response = GetStatus::CommandTransaction::run(device);
+          return response.data().card_serial_u32;
+        }
+          break;
+
+        case DeviceModel::STORAGE:
+        {
+          auto response = stick20::GetDeviceStatus::CommandTransaction::run(device);
+          return response.data().ActiveSmartCardID_u32;
+        }
+          break;
+      }
+      return 0;
+    }
+
     stick10::GetStatus::ResponsePayload NitrokeyManager::get_status(){
       try{
         auto response = GetStatus::CommandTransaction::run(device);
diff --git a/libnitrokey/NitrokeyManager.h b/libnitrokey/NitrokeyManager.h
index 33ede1b..163a799 100644
--- a/libnitrokey/NitrokeyManager.h
+++ b/libnitrokey/NitrokeyManager.h
@@ -104,6 +104,7 @@ char * strndup(const char* str, size_t maxlen);
         stick10::GetStatus::ResponsePayload get_status();
         string get_status_as_string();
         string get_serial_number();
+        uint32_t get_serial_number_as_u32();
 
         char * get_totp_slot_name(uint8_t slot_number);
         char * get_hotp_slot_name(uint8_t slot_number);
diff --git a/unittest/test_offline.cc b/unittest/test_offline.cc
index 320ad48..3ca3905 100644
--- a/unittest/test_offline.cc
+++ b/unittest/test_offline.cc
@@ -67,6 +67,10 @@ TEST_CASE("Test C++ side behaviour in offline", "[fast]") {
   REQUIRE(serial_number.empty());
 
   REQUIRE_THROWS_AS(
+    i->get_serial_number_as_u32(), DeviceNotConnected
+  );
+
+  REQUIRE_THROWS_AS(
     i->get_status(), DeviceNotConnected
   );