Add an example to configure MIFARE DESFire EV1 random UID.

Don't connect it to the build yet because the corresponding code in the library
has not been committed yet: I want to keep a track of modifications I do in the
VCS.

examples/mifare-desfire-ev1-configure-random-uid.c

@@ -0,0 +1,148 @@
+/*-
+ * Copyright (C) 2010, Romain Tartiere.
+ * 
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ * 
+ * $Id$
+ */
+
+#include "config.h"
+
+#include <err.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <nfc/nfc.h>
+
+#include <freefare.h>
+
+uint8_t null_key_data[8] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+
+struct {
+    bool interactive;
+} configure_options = {
+    .interactive = true
+};
+
+void
+usage(char *progname)
+{
+    fprintf (stderr, "usage: %s [-y]\n", progname);
+    fprintf (stderr, "\nOptions:\n");
+    fprintf (stderr, "  -y     Do not ask for confirmation (dangerous)\n");
+}
+
+int
+main(int argc, char *argv[])
+{
+    int ch;
+    int error = EXIT_SUCCESS;
+    nfc_device_t *device = NULL;
+    MifareTag *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);
+	}
+    }
+    argc -= optind;
+    argv += optind;
+
+    nfc_device_desc_t devices[8];
+    size_t device_count;
+
+    nfc_list_devices (devices, 8, &device_count);
+    if (!device_count)
+	errx (EXIT_FAILURE, "No NFC device found.");
+
+    for (size_t d = 0; d < device_count; d++) {
+	device = nfc_connect (&(devices[d]));
+	if (!device) {
+	    warnx ("nfc_connect() failed.");
+	    error = EXIT_FAILURE;
+	    continue;
+	}
+
+	tags = freefare_get_tags (device);
+	if (!tags) {
+	    nfc_disconnect (device);
+	    errx (EXIT_FAILURE, "Error listing Mifare DESFire tags.");
+	}
+
+	for (int i = 0; (!error) && tags[i]; i++) {
+	    if (DESFIRE != freefare_get_tag_type (tags[i]))
+		continue;
+
+	    char *tag_uid = freefare_get_tag_uid (tags[i]);
+	    char buffer[BUFSIZ];
+
+	    printf ("Found %s with UID %s. ", freefare_get_tag_friendly_name (tags[i]), tag_uid);
+	    bool do_it = true;
+	    if (configure_options.interactive) {
+		printf ("Configure random UID (this cannot be undone) [yN] ");
+		fgets (buffer, BUFSIZ, stdin);
+		do_it = ((buffer[0] == 'y') || (buffer[0] == 'Y'));
+	    } else {
+		printf ("\n");
+	    }
+
+	    if (do_it) {
+		int res;
+		MifareDESFireKey default_key = mifare_desfire_des_key_new_with_version (null_key_data);
+
+		res = mifare_desfire_connect (tags[i]);
+		if (res < 0) {
+		    warnx ("Can't connect to Mifare DESFire target.");
+		    error = EXIT_FAILURE;
+		    break;
+		}
+
+		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_configuration (tags[i], false, true);
+		if (res < 0) {
+		    freefare_perror (tags[i], "mifare_desfire_set_configuration");
+		    error = EXIT_FAILURE;
+		    break;
+		}
+
+		mifare_desfire_disconnect (tags[i]);
+	    }
+
+	    free (tag_uid);
+	}
+
+	freefare_free_tags (tags);
+	nfc_disconnect (device);
+    }
+
+    exit (error);
+} /* main() */
+