1 /*-
2 * Free/Libre Near Field Communication (NFC) library
3 *
4 * Libnfc historical contributors:
5 * Copyright (C) 2009 Roel Verdult
6 * Copyright (C) 2009-2013 Romuald Conty
7 * Copyright (C) 2010-2012 Romain Tartière
8 * Copyright (C) 2010-2013 Philippe Teuwen
9 * Copyright (C) 2012-2013 Ludovic Rousseau
10 * See AUTHORS file for a more comprehensive list of contributors.
11 * Additional contributors of this file:
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions are met:
15 * 1) Redistributions of source code must retain the above copyright notice,
16 * this list of conditions and the following disclaimer.
17 * 2 )Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
32 *
33 * Note that this license only applies on the examples, NFC library itself is under LGPL
34 *
35 */
36
37 /**
38 * @file nfc-anticol.c
39 * @brief Generates one ISO14443-A anti-collision process "by-hand"
40 */
41
42 #ifdef HAVE_CONFIG_H
43 # include "config.h"
44 #endif // HAVE_CONFIG_H
45
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <stddef.h>
49 #include <stdint.h>
50 #include <stdbool.h>
51 #include <string.h>
52
53 #include <nfc/nfc.h>
54
55 #include "utils/nfc-utils.h"
56
57 #define SAK_FLAG_ATS_SUPPORTED 0x20
58
59 #define MAX_FRAME_LEN 264
60
61 static uint8_t abtRx[MAX_FRAME_LEN];
62 static int szRxBits;
63 static size_t szRx = sizeof(abtRx);
64 static uint8_t abtRawUid[12];
65 static uint8_t abtAtqa[2];
66 static uint8_t abtSak;
67 static uint8_t abtAts[MAX_FRAME_LEN];
68 static uint8_t szAts = 0;
69 static size_t szCL = 1;//Always start with Cascade Level 1 (CL1)
70 static nfc_device *pnd;
71
72 bool quiet_output = false;
73 bool force_rats = false;
74 bool timed = false;
75 bool iso_ats_supported = false;
76
77 // ISO14443A Anti-Collision Commands
78 uint8_t abtReqa[1] = { 0x26 };
79 uint8_t abtSelectAll[2] = { 0x93, 0x20 };
80 uint8_t abtSelectTag[9] = { 0x93, 0x70, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
81 uint8_t abtRats[4] = { 0xe0, 0x50, 0x00, 0x00 };
82 uint8_t abtHalt[4] = { 0x50, 0x00, 0x00, 0x00 };
83 #define CASCADE_BIT 0x04
84
85 static bool
transmit_bits(const uint8_t * pbtTx,const size_t szTxBits)86 transmit_bits(const uint8_t *pbtTx, const size_t szTxBits)
87 {
88 uint32_t cycles = 0;
89 // Show transmitted command
90 if (!quiet_output) {
91 printf("Sent bits: ");
92 print_hex_bits(pbtTx, szTxBits);
93 }
94 // Transmit the bit frame command, we don't use the arbitrary parity feature
95 if (timed) {
96 if ((szRxBits = nfc_initiator_transceive_bits_timed(pnd, pbtTx, szTxBits, NULL, abtRx, sizeof(abtRx), NULL, &cycles)) < 0)
97 return false;
98 if ((!quiet_output) && (szRxBits > 0)) {
99 printf("Response after %u cycles\n", cycles);
100 }
101 } else {
102 if ((szRxBits = nfc_initiator_transceive_bits(pnd, pbtTx, szTxBits, NULL, abtRx, sizeof(abtRx), NULL)) < 0)
103 return false;
104 }
105 // Show received answer
106 if (!quiet_output) {
107 printf("Received bits: ");
108 print_hex_bits(abtRx, szRxBits);
109 }
110 // Succesful transfer
111 return true;
112 }
113
114
115 static bool
transmit_bytes(const uint8_t * pbtTx,const size_t szTx)116 transmit_bytes(const uint8_t *pbtTx, const size_t szTx)
117 {
118 uint32_t cycles = 0;
119 // Show transmitted command
120 if (!quiet_output) {
121 printf("Sent bits: ");
122 print_hex(pbtTx, szTx);
123 }
124 int res;
125 // Transmit the command bytes
126 if (timed) {
127 if ((res = nfc_initiator_transceive_bytes_timed(pnd, pbtTx, szTx, abtRx, sizeof(abtRx), &cycles)) < 0)
128 return false;
129 if ((!quiet_output) && (res > 0)) {
130 printf("Response after %u cycles\n", cycles);
131 }
132 } else {
133 if ((res = nfc_initiator_transceive_bytes(pnd, pbtTx, szTx, abtRx, sizeof(abtRx), 0)) < 0)
134 return false;
135 }
136 szRx = res;
137 // Show received answer
138 if (!quiet_output) {
139 printf("Received bits: ");
140 print_hex(abtRx, szRx);
141 }
142 // Succesful transfer
143 return true;
144 }
145
146 static void
print_usage(char * argv[])147 print_usage(char *argv[])
148 {
149 printf("Usage: %s [OPTIONS]\n", argv[0]);
150 printf("Options:\n");
151 printf("\t-h\tHelp. Print this message.\n");
152 printf("\t-q\tQuiet mode. Suppress output of READER and EMULATOR data (improves timing).\n");
153 printf("\t-f\tForce RATS.\n");
154 printf("\t-t\tMeasure response time (in cycles).\n");
155 }
156
157 int
main(int argc,char * argv[])158 main(int argc, char *argv[])
159 {
160 int arg;
161
162 // Get commandline options
163 for (arg = 1; arg < argc; arg++) {
164 if (0 == strcmp(argv[arg], "-h")) {
165 print_usage(argv);
166 exit(EXIT_SUCCESS);
167 } else if (0 == strcmp(argv[arg], "-q")) {
168 quiet_output = true;
169 } else if (0 == strcmp(argv[arg], "-f")) {
170 force_rats = true;
171 } else if (0 == strcmp(argv[arg], "-t")) {
172 timed = true;
173 } else {
174 ERR("%s is not supported option.", argv[arg]);
175 print_usage(argv);
176 exit(EXIT_FAILURE);
177 }
178 }
179
180 nfc_context *context;
181 nfc_init(&context);
182 if (context == NULL) {
183 ERR("Unable to init libnfc (malloc)");
184 exit(EXIT_FAILURE);
185 }
186
187 // Try to open the NFC reader
188 pnd = nfc_open(context, NULL);
189
190 if (pnd == NULL) {
191 ERR("Error opening NFC reader");
192 nfc_exit(context);
193 exit(EXIT_FAILURE);
194 }
195
196 // Initialise NFC device as "initiator"
197 if (nfc_initiator_init(pnd) < 0) {
198 nfc_perror(pnd, "nfc_initiator_init");
199 nfc_close(pnd);
200 nfc_exit(context);
201 exit(EXIT_FAILURE);
202 }
203
204 // Configure the CRC
205 if (nfc_device_set_property_bool(pnd, NP_HANDLE_CRC, false) < 0) {
206 nfc_perror(pnd, "nfc_device_set_property_bool");
207 nfc_close(pnd);
208 nfc_exit(context);
209 exit(EXIT_FAILURE);
210 }
211 // Use raw send/receive methods
212 if (nfc_device_set_property_bool(pnd, NP_EASY_FRAMING, false) < 0) {
213 nfc_perror(pnd, "nfc_device_set_property_bool");
214 nfc_close(pnd);
215 nfc_exit(context);
216 exit(EXIT_FAILURE);
217 }
218 // Disable 14443-4 autoswitching
219 if (nfc_device_set_property_bool(pnd, NP_AUTO_ISO14443_4, false) < 0) {
220 nfc_perror(pnd, "nfc_device_set_property_bool");
221 nfc_close(pnd);
222 nfc_exit(context);
223 exit(EXIT_FAILURE);
224 }
225
226 printf("NFC reader: %s opened\n\n", nfc_device_get_name(pnd));
227
228 // Send the 7 bits request command specified in ISO 14443A (0x26)
229 if (!transmit_bits(abtReqa, 7)) {
230 printf("Error: No tag available\n");
231 nfc_close(pnd);
232 nfc_exit(context);
233 exit(EXIT_FAILURE);
234 }
235 memcpy(abtAtqa, abtRx, 2);
236
237 // Anti-collision
238 transmit_bytes(abtSelectAll, 2);
239
240 // Check answer
241 if ((abtRx[0] ^ abtRx[1] ^ abtRx[2] ^ abtRx[3] ^ abtRx[4]) != 0) {
242 printf("WARNING: BCC check failed!\n");
243 }
244
245 // Save the UID CL1
246 memcpy(abtRawUid, abtRx, 4);
247
248 //Prepare and send CL1 Select-Command
249 memcpy(abtSelectTag + 2, abtRx, 5);
250 iso14443a_crc_append(abtSelectTag, 7);
251 transmit_bytes(abtSelectTag, 9);
252 abtSak = abtRx[0];
253
254 // Test if we are dealing with a CL2
255 if (abtSak & CASCADE_BIT) {
256 szCL = 2;//or more
257 // Check answer
258 if (abtRawUid[0] != 0x88) {
259 printf("WARNING: Cascade bit set but CT != 0x88!\n");
260 }
261 }
262
263 if (szCL == 2) {
264 // We have to do the anti-collision for cascade level 2
265
266 // Prepare CL2 commands
267 abtSelectAll[0] = 0x95;
268
269 // Anti-collision
270 transmit_bytes(abtSelectAll, 2);
271
272 // Check answer
273 if ((abtRx[0] ^ abtRx[1] ^ abtRx[2] ^ abtRx[3] ^ abtRx[4]) != 0) {
274 printf("WARNING: BCC check failed!\n");
275 }
276
277 // Save UID CL2
278 memcpy(abtRawUid + 4, abtRx, 4);
279
280 // Selection
281 abtSelectTag[0] = 0x95;
282 memcpy(abtSelectTag + 2, abtRx, 5);
283 iso14443a_crc_append(abtSelectTag, 7);
284 transmit_bytes(abtSelectTag, 9);
285 abtSak = abtRx[0];
286
287 // Test if we are dealing with a CL3
288 if (abtSak & CASCADE_BIT) {
289 szCL = 3;
290 // Check answer
291 if (abtRawUid[0] != 0x88) {
292 printf("WARNING: Cascade bit set but CT != 0x88!\n");
293 }
294 }
295
296 if (szCL == 3) {
297 // We have to do the anti-collision for cascade level 3
298
299 // Prepare and send CL3 AC-Command
300 abtSelectAll[0] = 0x97;
301 transmit_bytes(abtSelectAll, 2);
302
303 // Check answer
304 if ((abtRx[0] ^ abtRx[1] ^ abtRx[2] ^ abtRx[3] ^ abtRx[4]) != 0) {
305 printf("WARNING: BCC check failed!\n");
306 }
307
308 // Save UID CL3
309 memcpy(abtRawUid + 8, abtRx, 4);
310
311 // Prepare and send final Select-Command
312 abtSelectTag[0] = 0x97;
313 memcpy(abtSelectTag + 2, abtRx, 5);
314 iso14443a_crc_append(abtSelectTag, 7);
315 transmit_bytes(abtSelectTag, 9);
316 abtSak = abtRx[0];
317 }
318 }
319
320 // Request ATS, this only applies to tags that support ISO 14443A-4
321 if (abtRx[0] & SAK_FLAG_ATS_SUPPORTED) {
322 iso_ats_supported = true;
323 }
324 if ((abtRx[0] & SAK_FLAG_ATS_SUPPORTED) || force_rats) {
325 iso14443a_crc_append(abtRats, 2);
326 if (transmit_bytes(abtRats, 4)) {
327 memcpy(abtAts, abtRx, szRx);
328 szAts = szRx;
329 }
330 }
331
332 // Done, halt the tag now
333 iso14443a_crc_append(abtHalt, 2);
334 transmit_bytes(abtHalt, 4);
335
336 printf("\nFound tag with\n UID: ");
337 switch (szCL) {
338 case 1:
339 printf("%02x%02x%02x%02x", abtRawUid[0], abtRawUid[1], abtRawUid[2], abtRawUid[3]);
340 break;
341 case 2:
342 printf("%02x%02x%02x", abtRawUid[1], abtRawUid[2], abtRawUid[3]);
343 printf("%02x%02x%02x%02x", abtRawUid[4], abtRawUid[5], abtRawUid[6], abtRawUid[7]);
344 break;
345 case 3:
346 printf("%02x%02x%02x", abtRawUid[1], abtRawUid[2], abtRawUid[3]);
347 printf("%02x%02x%02x", abtRawUid[5], abtRawUid[6], abtRawUid[7]);
348 printf("%02x%02x%02x%02x", abtRawUid[8], abtRawUid[9], abtRawUid[10], abtRawUid[11]);
349 break;
350 }
351 printf("\n");
352 printf("ATQA: %02x%02x\n SAK: %02x\n", abtAtqa[1], abtAtqa[0], abtSak);
353 if (szAts > 1) { // if = 1, it's not actual ATS but error code
354 if (force_rats && ! iso_ats_supported) {
355 printf(" RATS forced\n");
356 }
357 printf(" ATS: ");
358 print_hex(abtAts, szAts);
359 }
360
361 nfc_close(pnd);
362 nfc_exit(context);
363 exit(EXIT_SUCCESS);
364 }
365