#include <err.h>
#include <stdlib.h>

#include <nfc/nfc.h>

#include <freefare.h>

int
main(int argc, char *argv[])
{
    int error = EXIT_SUCCESS;
    nfc_device *device = NULL;
    FreefareTag *tags = NULL;

    if (argc > 1)
	errx(EXIT_FAILURE, "usage: %s", argv[0]);

    nfc_connstring devices[8];
    size_t device_count;

    nfc_context *context;
    nfc_init(&context);
    if (context == NULL)
	errx(EXIT_FAILURE, "Unable to init libnfc (malloc)");

    device_count = nfc_list_devices(context, devices, sizeof(devices) / sizeof(*devices));
    if (device_count <= 0)
	errx(EXIT_FAILURE, "No NFC device found");

    for (size_t d = 0; d < device_count; d++) {
	if (!(device = nfc_open(context, devices[d]))) {
	    warnx("nfc_open() failed.");
	    error = EXIT_FAILURE;
	    continue;
	}

	if (!(tags = freefare_get_tags(device))) {
	    nfc_close(device);
	    errx(EXIT_FAILURE, "Error listing tags.");
	}

	for (int i = 0; (!error) && tags[i]; i++) {
	    switch (freefare_get_tag_type(tags[i])) {
	    case MIFARE_ULTRALIGHT:
	    case MIFARE_ULTRALIGHT_C:
		break;
	    default:
		continue;
	    }

	    char *tag_uid = freefare_get_tag_uid(tags[i]);
	    printf("Tag with UID %s is a %s\n", tag_uid, freefare_get_tag_friendly_name(tags[i]));
	    if (freefare_get_tag_type(tags[i]) == MIFARE_ULTRALIGHT_C) {
		FreefareTag tag = tags[i];
		int res;
		MifareDESFireKey key;
		uint8_t key1_3des_data[16] = { 0x49, 0x45, 0x4D, 0x4B, 0x41, 0x45, 0x52, 0x42, 0x21, 0x4E, 0x41, 0x43, 0x55, 0x4F, 0x59, 0x46 };
		key = mifare_desfire_3des_key_new(key1_3des_data);
		if (mifare_ultralight_connect(tag) < 0)
		    errx(EXIT_FAILURE, "Error connecting to tag.");
		res = mifare_ultralightc_authenticate(tag, key);
		if (res != 0) {
		    MifareDESFireKey diversified_key = NULL;
		    MifareKeyDeriver deriver = mifare_key_deriver_new_an10922(key, MIFARE_KEY_2K3DES, AN10922_FLAG_DEFAULT);

		    mifare_key_deriver_begin(deriver);
		    mifare_key_deriver_update_uid(deriver, tag);
		    diversified_key = mifare_key_deriver_end(deriver);

		    // Disconnect and reconnect.
		    mifare_ultralight_disconnect(tag);
		    if (mifare_ultralight_connect(tag) < 0)
			errx(EXIT_FAILURE, "Error connecting to tag.");

		    res = mifare_ultralightc_authenticate(tag, diversified_key);

		    printf("Authentication with default key: %s\n", res ? "fail" : "success (diversified)");

		    mifare_desfire_key_free(diversified_key);
		    mifare_key_deriver_free(deriver);
		} else {
		    printf("Authentication with default key: success\n");
		}
		mifare_desfire_key_free(key);
		mifare_ultralight_disconnect(tag);
	    }
	    free(tag_uid);
	}

	freefare_free_tags(tags);
	nfc_close(device);
    }

    nfc_exit(context);
    exit(error);
}