This commit is contained in:
Lynn Ochs 2022-11-22 17:13:29 +01:00
parent ffca3a719f
commit 084866dbbc
4 changed files with 188 additions and 87 deletions

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@ -1,8 +1,9 @@
VERSION ?= $(shell git rev-parse --short HEAD)
PKG_CONFIG ?= pkg-config
all: poll_desfire
poll_desfire: poll_desfire.o
poll_desfire: poll_desfire.o nfc_init.o
$(CC) $(LDFLAGS) $(shell $(PKG_CONFIG) --libs libfreefare) $^ -o $@
%.o: %.c

35
nfc_init.c Normal file
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@ -0,0 +1,35 @@
#include <err.h>
#include <errno.h>
#include <stdlib.h>
#include "poll_desfire.h"
int init(nfc_context **context, nfc_device **device) {
nfc_connstring devices[8];
size_t device_count;
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[0]));
if (device_count <= 0) {
errx(EXIT_FAILURE, "No NFC device found.");
}
if (device_count > 1) {
printf("More than 1 device available. Using %s\n", devices[0]);
}
*device = nfc_open(*context, devices[0]);
if (!device) {
errx(EXIT_FAILURE, "nfc_open() failed.");
}
if (nfc_initiator_init(*device) < 0) {
errx(EXIT_FAILURE, "Initiator failed.");
}
return 0;
}
void poll_target(nfc_device *device);

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@ -1,32 +1,21 @@
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <err.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "poll_desfire.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;
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)");
}
#define AID 0x22eaa0
#define RANDOM_UID_SIZE 8
void init_keys(MifareDESFireKey *null_key, MifareDESFireKey *master_key, char const *name) {
uint8_t const key_data_null[8] = {0, 0, 0, 0, 0, 0, 0, 0};
MifareDESFireKey key_null = mifare_desfire_des_key_new_with_version(key_data_null);
*null_key = mifare_desfire_des_key_new_with_version(key_data_null);
uint8_t key_data_real[16] = {0};
{
char const *name = (argc > 1) ? argv[1] : "key";
FILE *f = fopen(name, "rb");
if (!f) {
errx(EXIT_FAILURE, "error opening key file: %s", name);
@ -36,95 +25,165 @@ int main(int argc, char **argv) {
}
fclose(f);
}
MifareDESFireKey key_real = mifare_desfire_aes_key_new(key_data_real);
*master_key = mifare_desfire_aes_key_new(key_data_real);
}
int main(int argc, char **argv) {
int error = EXIT_SUCCESS;
nfc_context *context = NULL;
nfc_device *device = NULL;
FreefareTag *tags = NULL;
MifareDESFireKey key_null, key_master;
MifareDESFireAID aid = mifare_desfire_aid_new(AID);
error = init(&context, &device);
init_keys(&key_null, &key_master, (argc > 1) ? argv[1] : "key");
FILE *out = argc > 2 ? fopen(argv[2], "w") : stdout;
device_count = nfc_list_devices(context, devices, sizeof(devices) / sizeof(devices[0]));
if (device_count <= 0) {
errx(EXIT_FAILURE, "No NFC device found.");
}
if (device_count > 1) {
printf("More than 1 device available. Using %s\n", devices[0]);
}
device = nfc_open(context, devices[0]);
if (!device) {
errx(EXIT_FAILURE, "nfc_open() failed.");
}
if (nfc_initiator_init(device) < 0) {
errx(EXIT_FAILURE, "Initiator failed.");
}
while (true) {
/* Poll for targets */
const nfc_modulation nmModulations = {.nmt = NMT_ISO14443A, .nbr = NBR_106};
nfc_target target;
nfc_initiator_poll_target(device, &nmModulations, 1, 10, 1, &target);
/* Got at least one, read tag list */
tags = freefare_get_tags(device);
if (!tags) {
nfc_close(device);
errx(EXIT_FAILURE, "Error listing tags.");
}
if (!tags[0]) {
goto free_tags;
}
FreefareTag tag = tags[0];
for (int id = 0; tags[id]; id++) {
FreefareTag tag = tags[id];
if (MIFARE_DESFIRE != freefare_get_tag_type(tag))
goto free_tags;
continue;
char *tag_uid = freefare_get_tag_uid(tag);
/* Result of various operations */
int res;
res = mifare_desfire_connect(tag);
if (res < 0) {
warnx("Can't connect to Mifare DESFire target.");
goto free_tag;
goto next_tag;
}
res = mifare_desfire_authenticate(tag, 0, key_null);
if (mifare_desfire_select_application(tag, aid) != 0) {
// Check for old card with our key as master key
res = mifare_desfire_authenticate(tag, 0, key_master);
if (res >= 0) {
// Default key still active, create new key
res = mifare_desfire_change_key(tag, 0, key_real, key_null);
warnx("Old tag detected: %s", tag_uid);
res = mifare_desfire_change_key(tag, 0, key_master, key_null);
}
// Card needs to have default null key as master
res = mifare_desfire_authenticate(tag, 0, key_null);
if (res < 0) {
warnx("Error changing key");
goto free_tag;
warnx("Could not authenticate: %d", res);
goto next_tag;
}
// create application
res = mifare_desfire_create_application_aes(tag, aid, MDAPP_SETTINGS(0, 1, 0, 0, 1), 1);
if (res < 0) {
warnx("Could not create application: %d", res);
goto next_tag;
}
// Select it
res = mifare_desfire_select_application(tag, aid);
if (res < 0) {
warnx("Application not selectable after creation: %d", res);
goto next_tag;
}
// Key should be null
res = mifare_desfire_authenticate_aes(tag, 0, key_null);
if (res < 0) {
warnx("Could not authenticate new application with default key: %d", res);
goto next_tag;
}
// Update to our key
res = mifare_desfire_change_key(tag, 0, key_master, key_null);
if (res < 0) {
warnx("Could not change key of new application to master key: %d", res);
goto next_tag;
}
// Authenticate with new key
res = mifare_desfire_authenticate_aes(tag, 0, key_master);
if (res < 0) {
warnx("Could not authenticate new application with our key: %d", res);
goto next_tag;
}
// Create file
res = mifare_desfire_create_std_data_file(tag, 0, 0, MDAR(0, 0, 0, 0), RANDOM_UID_SIZE);
if (res < 0) {
warnx("Could not create data file: %d", res);
goto next_tag;
}
// Grab random data for it
unsigned char uid_data[RANDOM_UID_SIZE];
{
int fd = open("/dev/urandom", O_RDONLY);
if (fd < 0) {
warnx("Could not open /dev/urandom");
goto next_tag;
}
if (RANDOM_UID_SIZE != read(fd, &uid_data[0], RANDOM_UID_SIZE)) {
warnx("Could not read data from /dev/random");
goto next_tag;
}
close(fd);
}
// Write data
res = mifare_desfire_write_data(tag, 0, 0, RANDOM_UID_SIZE, &uid_data[0]);
if (res < 0) {
warnx("Could not write UID data to tag: %d", res);
goto next_tag;
}
}
res = mifare_desfire_authenticate_aes(tag, 0, key_real);
// Authenticate with our key
res = mifare_desfire_authenticate_aes(tag, 0, key_master);
if (res < 0) {
warnx("Authentication on master application failed");
goto free_tag;
} else {
fprintf(out, "%s\n", tag_uid);
warnx("Authentication on application failed: %d", res);
goto next_tag;
}
// Grab UID
uint8_t data[RANDOM_UID_SIZE];
res = mifare_desfire_read_data(tag, 0, 0, RANDOM_UID_SIZE, &data[0]);
if (res != RANDOM_UID_SIZE) {
warnx("Could not read all bytes from tag: %d", res);
goto next_tag;
}
// Print out key ID and UID
fprintf(out, "%s:", tag_uid);
for (int j = 0; j < RANDOM_UID_SIZE; j++) {
fprintf(out, "%02x", data[j]);
}
fprintf(out, "\n");
fflush(out);
next_tag:
free(tag_uid);
mifare_desfire_disconnect(tag);
}
wait_disconnect:
while (0 == nfc_initiator_target_is_present(device, 0))
while (freefare_selected_tag_is_present(device))
;
mifare_desfire_disconnect(tag);
free_tag:
free(tag_uid);
free_tags:
freefare_free_tags(tags);
fflush(stdout);
fflush(stderr);
}
mifare_desfire_key_free(key_null);
mifare_desfire_key_free(key_real);
mifare_desfire_key_free(key_master);
nfc_close(device);
nfc_exit(context);

6
poll_desfire.h Normal file
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@ -0,0 +1,6 @@
#include <nfc/nfc.h>
#include <freefare.h>
int init(nfc_context **context, nfc_device **device);
void poll_target(nfc_device *device);