Return serial number as uint32_t from C API

This patch adds the function NK_device_serial_number_as_u32 to the C
API.  It is similar to NK_device_serial_number but returns the raw
unsigned integer instead of a formatted string.  This patch also adds a
simple test case that ensures that the number is not zero.

Fixes #172.

1 files changed, 7 insertions, 0 deletions

diff --git a/NK_C_API.cc b/NK_C_API.cc
index 1d3fa3a..c44e36f 100644
--- a/NK_C_API.cc
+++ b/NK_C_API.cc
@@ -299,6 +299,13 @@ extern "C" {
 		});
 	}
 
+	NK_C_API uint32_t NK_device_serial_number_as_u32() {
+		auto m = NitrokeyManager::instance();
+		return get_with_result([&]() {
+                        return m->get_serial_number_as_u32();
+		});
+	}
+
 	NK_C_API char * NK_get_hotp_code(uint8_t slot_number) {
 		return NK_get_hotp_code_PIN(slot_number, "");
 	}