Add NK_config struct and read/write functions

This patch adds the NK_config struct to the C API that stores the
general configuration of a Nitrokey device.  It also adds the
NK_read_config_struct and NK_write_config_struct functions to make the
API easier to use.  While NK_write_config_struct is only a convenience
method, NK_read_config_struct makes the API more safe as the user no
longer has to read the data from a pointer to an array.

This patch also extends the test_read_write_config test case with the
two new functions.

1 files changed, 21 insertions, 0 deletions

diff --git a/NK_C_API.cc b/NK_C_API.cc
index 1d3fa3a..d993671 100644
--- a/NK_C_API.cc
+++ b/NK_C_API.cc
@@ -217,6 +217,12 @@ extern "C" {
 		});
 	}
 
+	NK_C_API int NK_write_config_struct(struct NK_config config,
+		const char *admin_temporary_password) {
+                return NK_write_config(config.numlock, config.capslock, config.scrolllock, config.enable_user_password,
+                    config.disable_user_password, admin_temporary_password);
+        }
+
 
 	NK_C_API uint8_t* NK_read_config() {
 		auto m = NitrokeyManager::instance();
@@ -226,6 +232,21 @@ extern "C" {
 		});
 	}
 
+	NK_C_API int NK_read_config_struct(struct NK_config* out) {
+		if (out == nullptr) {
+			return -1;
+		}
+		auto m = NitrokeyManager::instance();
+		return get_without_result([&]() {
+			auto v = m->read_config();
+                        out->numlock = v[0];
+                        out->capslock = v[1];
+                        out->scrolllock = v[2];
+                        out->enable_user_password = v[3];
+                        out->disable_user_password = v[4];
+		});
+	}
+
 
 	NK_C_API enum NK_device_model NK_get_device_model() {
 		auto m = NitrokeyManager::instance();