libfreefare/examples/ntag-write.c
2017-06-27 10:50:50 +02:00

119 lines
3.3 KiB
C

/*-
* Copyright (C) 2012, 2017 Romain Tartiere, Martin Dagarin (SloCompTech).
*
* 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/>
*/
#include <err.h>
#include <stdlib.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;
if (argc > 1)
errx(EXIT_FAILURE, "usage: %s", argv[0]);
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, sizeof (devices) / sizeof (*devices));
if (device_count <= 0)
errx(EXIT_FAILURE, "No NFC device found");
for (size_t d = 0; d < device_count; d++) {
if (!(device = nfc_open(context, devices[d]))) {
warnx("nfc_open() failed.");
error = EXIT_FAILURE;
continue;
}
if (!(tags = freefare_get_tags(device))) {
nfc_close(device);
errx(EXIT_FAILURE, "Error listing tags.");
}
for (int i = 0; (!error) && tags[i]; i++) {
switch (freefare_get_tag_type(tags[i])) {
case NTAG_21x:
break;
default:
continue;
}
char *tag_uid = freefare_get_tag_uid(tags[i]);
printf("Tag with UID %s is a %s\n", tag_uid, freefare_get_tag_friendly_name (tags[i]));
FreefareTag tag = tags[i];
int res;
if (ntag21x_connect(tag) < 0)
errx(EXIT_FAILURE, "Error connecting to tag.");
uint8_t data [4] = {0xfa,0xca,0xac,0xad}; // Data to write on tag
uint8_t read[4]; // Buffer for reading data from tag
bool flag_match = true;
switch (true) {
case true:
/*
Get information about tag
MUST do, because here we are recognizing tag subtype (NTAG213,NTAG215,NTAG216), and gathering all parameters
*/
res = ntag21x_get_info(tag);
if(res < 0) {
printf("Error getting info from tag\n");
break;
}
// writing to tag 4 bytes on page 0x27 (check specs for NTAG21x before changing page number !!!)
res = ntag21x_write(tag,0x27,data);
if(res < 0) {
printf("Error writing to tag\n");
break;
}
res = ntag21x_fast_read4(tag,0x27,read); // Reading page from tag (4 bytes), you can also use ntag21x_read4 or ntag21x_read (16 bytes) or ntag21x_fast_read (start_page to end_page)
if(res < 0) {
printf("Error reading tag\n");
break;
}
for(int i=0;i < 4;i++) // Checking if we can read what we have written earlyer
if(data[i] != read[i]) {
flag_match = false;
break;
}
if(!flag_match)
printf("Data don't match\n");
else
printf("Data match\n");
}
ntag21x_disconnect(tag);
free(tag_uid);
}
freefare_free_tags(tags);
nfc_close(device);
}
nfc_exit(context);
exit(error);
}