int write_encrypted_tag_key (MifareTag tag, keyvault_t *kv, RSA *global_public, RSA *shop_public, RSA *shop_private, size_t len)
{
int res = 0;
uint8_t *crypted = malloc (RSA_size(global_public));
res = RSA_public_encrypt (len, (unsigned char*) kv->k, (unsigned char*) crypted, global_public, RSA_PKCS1_PADDING);
if (res < 0)
fprintf (stderr, "Something went wrong while ciphering\n");
printf ("Encrypted key has length %d\n", RSA_size(global_public));
unsigned int siglen = RSA_size (shop_private);
unsigned int digestlen = RSA_size(global_public);
unsigned char *digest = digest_message (crypted, &digestlen);
uint8_t *signature = malloc (siglen);
res = RSA_sign (NID_sha1, digest, digestlen, (unsigned char *) signature, &siglen , shop_private);
if (res <= 0)
fprintf (stderr, "Something went wrong while signing\n");
res = RSA_verify (NID_sha1, (unsigned char*) digest, digestlen, (unsigned char *) signature, siglen, shop_public);
if (res <= 0)
fprintf (stderr, "Something went wrong while signing, can't verify the thing with our pubkey\n");
MifareDESFireAID aid = mifare_desfire_aid_new (0x1);
res = mifare_desfire_select_application(tag, aid);
if (res < 0)
errx (EXIT_FAILURE, "Application selection failed");
free (aid);
MifareDESFireKey key = mifare_desfire_3des_key_new_with_version (kv->k_w_1);
mifare_desfire_key_set_version (key, 0x01);
res = mifare_desfire_authenticate (tag, 1, key);
if (res < 0)
freefare_perror(tag, "Authentication to application #1 failed");
mifare_desfire_key_free (key);
ssize_t written = mifare_desfire_write_data (tag, 0x01, 0x0, 0x80, crypted);
if (written < 0)
freefare_perror(tag, "Writing data to tag");
else
printf ("Wrote %ld bytes E(K) to card ...\n", written);
written = mifare_desfire_write_data (tag, 0x02, 0x0, 0x80, signature);
if (written < 0)
freefare_perror(tag, "Writing data to tag");
else
printf ("Wrote %ld bytes Sign(E(K)) to card ...\n", written);
free (crypted);
free (signature);
free (digest);
return res;
}
int
main(int argc, char *argv[])
{
int ch;
int error = EXIT_SUCCESS;
nfc_device *device = NULL;
FreefareTag *tags = NULL;
while ((ch = getopt (argc, argv, "hy")) != -1) {
switch (ch) {
case 'h':
usage(argv[0]);
exit (EXIT_SUCCESS);
break;
case 'y':
configure_options.interactive = false;
break;
default:
usage(argv[0]);
exit (EXIT_FAILURE);
}
}
// Remaining args, if any, are in argv[optind .. (argc-1)]
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, 8);
if (device_count <= 0)
errx (EXIT_FAILURE, "No NFC device found.");
for (size_t d = 0; (!error) && (d < device_count); d++) {
device = nfc_open (context, devices[d]);
if (!device) {
warnx ("nfc_open() failed.");
error = EXIT_FAILURE;
continue;
}
tags = freefare_get_tags (device);
if (!tags) {
nfc_close (device);
errx (EXIT_FAILURE, "Error listing Mifare DESFire tags.");
}
for (int i = 0; (!error) && tags[i]; i++) {
if (MIFARE_DESFIRE != freefare_get_tag_type (tags[i]))
continue;
char *tag_uid = freefare_get_tag_uid (tags[i]);
char buffer[BUFSIZ];
int res;
res = mifare_desfire_connect (tags[i]);
if (res < 0) {
warnx ("Can't connect to Mifare DESFire target.");
error = EXIT_FAILURE;
break;
}
// Make sure we've at least an EV1 version
struct mifare_desfire_version_info info;
res = mifare_desfire_get_version (tags[i], &info);
if (res < 0) {
freefare_perror (tags[i], "mifare_desfire_get_version");
error = 1;
break;
}
if (info.software.version_major < 1) {
warnx ("Found old DESFire, skipping");
continue;
}
printf ("Found %s with UID %s. ", freefare_get_tag_friendly_name (tags[i]), tag_uid);
bool do_it = true;
if (configure_options.interactive) {
printf ("Change default key? [yN] ");
fgets (buffer, BUFSIZ, stdin);
do_it = ((buffer[0] == 'y') || (buffer[0] == 'Y'));
} else {
printf ("\n");
}
if (do_it) {
MifareDESFireKey default_key = mifare_desfire_des_key_new_with_version (null_key_data);
res = mifare_desfire_authenticate (tags[i], 0, default_key);
if (res < 0) {
freefare_perror (tags[i], "mifare_desfire_authenticate");
error = EXIT_FAILURE;
break;
}
mifare_desfire_key_free (default_key);
MifareDESFireKey new_key = mifare_desfire_des_key_new (new_key_data);
mifare_desfire_key_set_version (new_key, NEW_KEY_VERSION);
res = mifare_desfire_set_default_key (tags[i], new_key);
free (new_key);
if (res < 0) {
freefare_perror (tags[i], "mifare_desfire_set_default_key");
error = EXIT_FAILURE;
break;
}
/*
* Perform some tests to ensure the function actually worked
* (it's hard to create a unit-test to do so).
*/
MifareDESFireAID aid = mifare_desfire_aid_new (0x112233);
res = mifare_desfire_create_application (tags[i], aid, 0xFF, 1);
if (res < 0) {
freefare_perror (tags[i], "mifare_desfire_create_application");
error = EXIT_FAILURE;
break;
}
res = mifare_desfire_select_application (tags[i], aid);
if (res < 0) {
freefare_perror (tags[i], "mifare_desfire_select_application");
error = EXIT_FAILURE;
break;
}
uint8_t version;
res = mifare_desfire_get_key_version (tags[i], 0, &version);
if (res < 0) {
freefare_perror (tags[i], "mifare_desfire_get_key_version");
error = EXIT_FAILURE;
break;
}
if (version != NEW_KEY_VERSION) {
fprintf (stderr, "Wrong key version: %02x (expected %02x).\n", version, NEW_KEY_VERSION);
error = EXIT_FAILURE;
/* continue */
}
new_key = mifare_desfire_des_key_new (new_key_data);
res = mifare_desfire_authenticate (tags[i], 0, new_key);
free (new_key);
if (res < 0) {
freefare_perror (tags[i], "mifare_desfire_authenticate");
error = EXIT_FAILURE;
break;
}
free (aid);
/* Resetdefault settings */
res = mifare_desfire_select_application (tags[i], NULL);
if (res < 0) {
freefare_perror (tags[i], "mifare_desfire_select_application");
error = EXIT_FAILURE;
break;
}
default_key = mifare_desfire_des_key_new (null_key_data);
res = mifare_desfire_authenticate (tags[i], 0, default_key);
if (res < 0) {
freefare_perror (tags[i], "mifare_desfire_authenticate");
error = EXIT_FAILURE;
break;
}
res = mifare_desfire_set_default_key (tags[i], default_key);
if (res < 0) {
freefare_perror (tags[i], "mifare_desfire_set_default_key");
error = EXIT_FAILURE;
break;
}
mifare_desfire_key_free (default_key);
/* Wipeout the card */
res = mifare_desfire_format_picc (tags[i]);
if (res < 0) {
freefare_perror (tags[i], "mifare_desfire_format_picc");
error = EXIT_FAILURE;
break;
}
}
mifare_desfire_disconnect (tags[i]);
free (tag_uid);
}
freefare_free_tags (tags);
nfc_close (device);
}
nfc_exit (context);
exit (error);
}
