Formatting

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

nfc_init.c

@@ -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);

poll_desfire.c

@@ -1,133 +1,206 @@
+#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>
+#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};
+	*null_key                      = mifare_desfire_des_key_new_with_version(key_data_null);
+
+	uint8_t key_data_real[16] = {0};
+	{
+		FILE *f = fopen(name, "rb");
+		if (!f) {
+			errx(EXIT_FAILURE, "error opening key file: %s", name);
+		}
+		if (fread(key_data_real, 1, sizeof key_data_real, f) < sizeof key_data_real) {
+			errx(EXIT_FAILURE, "key file too small.");
+		}
+		fclose(f);
+	}
+	*master_key = mifare_desfire_aes_key_new(key_data_real);
+}
 
 int main(int argc, char **argv) {
-  int error = EXIT_SUCCESS;
+	int error = EXIT_SUCCESS;
 
-  nfc_device *device = NULL;
-  FreefareTag *tags  = NULL;
+	nfc_context *context = NULL;
+	nfc_device *device   = NULL;
+	FreefareTag *tags    = NULL;
+	MifareDESFireKey key_null, key_master;
+	MifareDESFireAID aid = mifare_desfire_aid_new(AID);
 
-  nfc_connstring devices[8];
-  size_t device_count;
+	error = init(&context, &device);
+	init_keys(&key_null, &key_master, (argc > 1) ? argv[1] : "key");
 
-  nfc_context *context;
-  nfc_init(&context);
-  if (context == NULL) {
-    errx(EXIT_FAILURE, "Unable to init libnfc (malloc)");
-  }
+	FILE *out = argc > 2 ? fopen(argv[2], "w") : stdout;
 
-  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);
+	while (true) {
+		tags = freefare_get_tags(device);
+		if (!tags) {
+			nfc_close(device);
+			errx(EXIT_FAILURE, "Error listing tags.");
+		}
 
-  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);
-    }
-    if (fread(key_data_real, 1, sizeof key_data_real, f) < sizeof key_data_real) {
-      errx(EXIT_FAILURE, "key file too small.");
-    }
-    fclose(f);
-  }
-  MifareDESFireKey key_real = mifare_desfire_aes_key_new(key_data_real);
+		for (int id = 0; tags[id]; id++) {
+			FreefareTag tag = tags[id];
+			if (MIFARE_DESFIRE != freefare_get_tag_type(tag))
+				continue;
 
-  FILE *out = argc > 2 ? fopen(argv[2], "w") : stdout;
+			char *tag_uid = freefare_get_tag_uid(tag);
+			/* Result of various operations */
+			int res;
 
-  device_count = nfc_list_devices(context, devices, sizeof(devices) / sizeof(devices[0]));
-  if (device_count <= 0) {
-    errx(EXIT_FAILURE, "No NFC device found.");
-  }
+			res = mifare_desfire_connect(tag);
+			if (res < 0) {
+				warnx("Can't connect to Mifare DESFire target.");
+				goto next_tag;
+			}
 
-  if (device_count > 1) {
-    printf("More than 1 device available. Using %s\n", devices[0]);
-  }
+			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);
+				}
 
-  device = nfc_open(context, devices[0]);
-  if (!device) {
-    errx(EXIT_FAILURE, "nfc_open() failed.");
-  }
+				// 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;
+				}
 
-  if (nfc_initiator_init(device) < 0) {
-    errx(EXIT_FAILURE, "Initiator failed.");
-  }
+				// 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;
+				}
 
-  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);
+				// Select it
+				res = mifare_desfire_select_application(tag, aid);
+				if (res < 0) {
+					warnx("Application not selectable after creation: %d", res);
+					goto next_tag;
+				}
 
-    /* Got at least one, read tag list */
-    tags = freefare_get_tags(device);
-    if (!tags) {
-      nfc_close(device);
-      errx(EXIT_FAILURE, "Error listing tags.");
-    }
+				// 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;
+				}
 
-    if (!tags[0]) {
-      goto free_tags;
-    }
+				// 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;
+				}
 
-    FreefareTag tag = tags[0];
-    if (MIFARE_DESFIRE != freefare_get_tag_type(tag))
-      goto free_tags;
+				// 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;
+				}
 
-    char *tag_uid = freefare_get_tag_uid(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;
+				}
 
-    /* Result of various operations */
-    int res;
+				// 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;
+					}
 
-    res = mifare_desfire_connect(tag);
-    if (res < 0) {
-      warnx("Can't connect to Mifare DESFire target.");
-      goto free_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);
+				}
 
-    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);
+				// 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;
+				}
+			}
 
-      if (res < 0) {
-        warnx("Error changing key");
-        goto free_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;
+			}
 
-    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);
-      fflush(out);
-    }
+			// 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;
+			}
 
-  wait_disconnect:
-    while (0 == nfc_initiator_target_is_present(device, 0))
-      ;
-    mifare_desfire_disconnect(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);
 
-  free_tag:
-    free(tag_uid);
-  free_tags:
-    freefare_free_tags(tags);
-    fflush(stdout);
-    fflush(stderr);
-  }
+		next_tag:
+			free(tag_uid);
 
-  mifare_desfire_key_free(key_null);
-  mifare_desfire_key_free(key_real);
+			mifare_desfire_disconnect(tag);
+		}
 
-  nfc_close(device);
-  nfc_exit(context);
+		while (freefare_selected_tag_is_present(device))
+			;
 
-  exit(error);
+		freefare_free_tags(tags);
+		fflush(stdout);
+		fflush(stderr);
+	}
+
+	mifare_desfire_key_free(key_null);
+	mifare_desfire_key_free(key_master);
+
+	nfc_close(device);
+	nfc_exit(context);
+
+	exit(error);
 }

poll_desfire.h

@@ -0,0 +1,5 @@
+#include <nfc/nfc.h>
+#include <freefare.h>
+
+int init(nfc_context **context, nfc_device **device);
+void poll_target(nfc_device *device);