From 084866dbbce3b961f745cdb5af05f5e115cdb890 Mon Sep 17 00:00:00 2001 From: Valentin Ochs Date: Tue, 22 Nov 2022 17:13:29 +0100 Subject: [PATCH] Rewrite --- Makefile | 3 +- nfc_init.c | 35 ++++++++ poll_desfire.c | 231 +++++++++++++++++++++++++++++++------------------ poll_desfire.h | 6 ++ 4 files changed, 188 insertions(+), 87 deletions(-) create mode 100644 nfc_init.c create mode 100644 poll_desfire.h diff --git a/Makefile b/Makefile index b732920..14814ac 100644 --- a/Makefile +++ b/Makefile @@ -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 diff --git a/nfc_init.c b/nfc_init.c new file mode 100644 index 0000000..1b26f13 --- /dev/null +++ b/nfc_init.c @@ -0,0 +1,35 @@ +#include +#include +#include +#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); diff --git a/poll_desfire.c b/poll_desfire.c index 655b08f..d3d7b32 100644 --- a/poll_desfire.c +++ b/poll_desfire.c @@ -1,32 +1,21 @@ +#include +#include +#include #include #include #include #include +#include "poll_desfire.h" -#include -#include - -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]; - if (MIFARE_DESFIRE != freefare_get_tag_type(tag)) - goto free_tags; - - 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; - } - - res = mifare_desfire_authenticate(tag, 0, key_null); - if (res >= 0) { - // Default key still active, create new key - res = mifare_desfire_change_key(tag, 0, key_real, key_null); - + for (int id = 0; tags[id]; id++) { + FreefareTag tag = tags[id]; + if (MIFARE_DESFIRE != freefare_get_tag_type(tag)) + continue; + + char *tag_uid = freefare_get_tag_uid(tag); + /* Result of various operations */ + int res; + + res = mifare_desfire_connect(tag); if (res < 0) { - warnx("Error changing key"); - goto free_tag; + warnx("Can't connect to Mifare DESFire target."); + goto next_tag; } - } - res = mifare_desfire_authenticate_aes(tag, 0, key_real); - if (res < 0) { - warnx("Authentication on master application failed"); - goto free_tag; - } else { - fprintf(out, "%s\n", tag_uid); + 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) { + 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("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; + } + } + + // Authenticate with our key + res = mifare_desfire_authenticate_aes(tag, 0, key_master); + if (res < 0) { + 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); diff --git a/poll_desfire.h b/poll_desfire.h new file mode 100644 index 0000000..c012eb6 --- /dev/null +++ b/poll_desfire.h @@ -0,0 +1,6 @@ +#include +#include + +int init(nfc_context **context, nfc_device **device); +void poll_target(nfc_device *device); +