fd71430bf04ba1906a75c3cae42988079d1844c2
[proxmark3-svn] / armsrc / epa.c
1 //-----------------------------------------------------------------------------
2 // Frederik Möllers - August 2012
3 //
4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
5 // at your option, any later version. See the LICENSE.txt file for the text of
6 // the license.
7 //-----------------------------------------------------------------------------
8 // Routines to support the German electronic "Personalausweis" (ID card)
9 // Note that the functions which do not implement USB commands do NOT initialize
10 // the card (with iso14443a_select_card etc.). If You want to use these
11 // functions, You need to do the setup before calling them!
12 //-----------------------------------------------------------------------------
13
14 #include "apps.h"
15 #include "iso14443a.h"
16 #include "iso14443b.h"
17 #include "epa.h"
18 #include "cmd.h"
19 #include "fpgaloader.h"
20 #include "string.h"
21 #include "util.h"
22
23 // Protocol and Parameter Selection Request for ISO 14443 type A cards
24 // use regular (1x) speed in both directions
25 // CRC is already included
26 static const uint8_t pps[] = {0xD0, 0x11, 0x00, 0x52, 0xA6};
27
28 // APDUs for communication with German Identification Card
29
30 // General Authenticate (request encrypted nonce) WITHOUT the Le at the end
31 static const uint8_t apdu_general_authenticate_pace_get_nonce[] = {
32 0x10, // CLA
33 0x86, // INS
34 0x00, // P1
35 0x00, // P2
36 0x02, // Lc
37 0x7C, // Type: Dynamic Authentication Data
38 0x00, // Length: 0 bytes
39 };
40
41 // MSE: Set AT (only CLA, INS, P1 and P2)
42 static const uint8_t apdu_mse_set_at_start[] = {
43 0x00, // CLA
44 0x22, // INS
45 0xC1, // P1
46 0xA4, // P2
47 };
48
49 // SELECT BINARY with the ID for EF.CardAccess
50 static const uint8_t apdu_select_binary_cardaccess[] = {
51 0x00, // CLA
52 0xA4, // INS
53 0x02, // P1
54 0x0C, // P2
55 0x02, // Lc
56 0x01, // ID
57 0x1C // ID
58 };
59
60 // READ BINARY
61 static const uint8_t apdu_read_binary[] = {
62 0x00, // CLA
63 0xB0, // INS
64 0x00, // P1
65 0x00, // P2
66 0x38 // Le
67 };
68
69
70 // the leading bytes of a PACE OID
71 static const uint8_t oid_pace_start[] = {
72 0x04, // itu-t, identified-organization
73 0x00, // etsi
74 0x7F, // reserved
75 0x00, // etsi-identified-organization
76 0x07, // bsi-de
77 0x02, // protocols
78 0x02, // smartcard
79 0x04 // id-PACE
80 };
81
82 // APDUs for replaying:
83 // MSE: Set AT (initiate PACE)
84 static uint8_t apdu_replay_mse_set_at_pace[41];
85 // General Authenticate (Get Nonce)
86 static uint8_t apdu_replay_general_authenticate_pace_get_nonce[8];
87 // General Authenticate (Map Nonce)
88 static uint8_t apdu_replay_general_authenticate_pace_map_nonce[75];
89 // General Authenticate (Mutual Authenticate)
90 static uint8_t apdu_replay_general_authenticate_pace_mutual_authenticate[75];
91 // General Authenticate (Perform Key Agreement)
92 static uint8_t apdu_replay_general_authenticate_pace_perform_key_agreement[18];
93 // pointers to the APDUs (for iterations)
94 static struct {
95 uint8_t len;
96 uint8_t *data;
97 } const apdus_replay[] = {
98 {sizeof(apdu_replay_mse_set_at_pace), apdu_replay_mse_set_at_pace},
99 {sizeof(apdu_replay_general_authenticate_pace_get_nonce), apdu_replay_general_authenticate_pace_get_nonce},
100 {sizeof(apdu_replay_general_authenticate_pace_map_nonce), apdu_replay_general_authenticate_pace_map_nonce},
101 {sizeof(apdu_replay_general_authenticate_pace_mutual_authenticate), apdu_replay_general_authenticate_pace_mutual_authenticate},
102 {sizeof(apdu_replay_general_authenticate_pace_perform_key_agreement), apdu_replay_general_authenticate_pace_perform_key_agreement}
103 };
104
105 // lengths of the replay APDUs
106 static uint8_t apdu_lengths_replay[5];
107
108 // type of card (ISO 14443 A or B)
109 static char iso_type = 0;
110
111 //-----------------------------------------------------------------------------
112 // Wrapper for sending APDUs to type A and B cards
113 //-----------------------------------------------------------------------------
114 int EPA_APDU(uint8_t *apdu, size_t length, uint8_t *response)
115 {
116 switch(iso_type)
117 {
118 case 'a':
119 return iso14_apdu(apdu, (uint16_t) length, response);
120 break;
121 case 'b':
122 return iso14443b_apdu(apdu, length, response);
123 break;
124 default:
125 return 0;
126 break;
127 }
128 }
129
130 //-----------------------------------------------------------------------------
131 // Closes the communication channel and turns off the field
132 //-----------------------------------------------------------------------------
133 void EPA_Finish()
134 {
135 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
136 LEDsoff();
137 iso_type = 0;
138 }
139
140 //-----------------------------------------------------------------------------
141 // Parses DER encoded data, e.g. from EF.CardAccess and fills out the given
142 // structs. If a pointer is 0, it is ignored.
143 // The function returns 0 on success and if an error occured, it returns the
144 // offset where it occured.
145 //
146 // TODO: This function can access memory outside of the given data if the DER
147 // encoding is broken
148 // TODO: Support skipping elements with a length > 0x7F
149 // TODO: Support OIDs with a length > 7F
150 // TODO: Support elements with long tags (tag is longer than 1 byte)
151 // TODO: Support proprietary PACE domain parameters
152 //-----------------------------------------------------------------------------
153 size_t EPA_Parse_CardAccess(uint8_t *data,
154 size_t length,
155 pace_version_info_t *pace_info)
156 {
157 size_t index = 0;
158
159 while (index <= length - 2) {
160 // determine type of element
161 // SET or SEQUENCE
162 if (data[index] == 0x31 || data[index] == 0x30) {
163 // enter the set (skip tag + length)
164 index += 2;
165 // check for extended length
166 if ((data[index - 1] & 0x80) != 0) {
167 index += (data[index-1] & 0x7F);
168 }
169 }
170 // OID
171 else if (data[index] == 0x06) {
172 // is this a PACE OID?
173 if (data[index + 1] == 0x0A // length matches
174 && memcmp(data + index + 2,
175 oid_pace_start,
176 sizeof(oid_pace_start)) == 0 // content matches
177 && pace_info != NULL)
178 {
179 // first, clear the pace_info struct
180 memset(pace_info, 0, sizeof(pace_version_info_t));
181 memcpy(pace_info->oid, data + index + 2, sizeof(pace_info->oid));
182 // a PACE OID is followed by the version
183 index += data[index + 1] + 2;
184 if (data[index] == 02 && data[index + 1] == 01) {
185 pace_info->version = data[index + 2];
186 index += 3;
187 }
188 else {
189 return index;
190 }
191 // after that there might(!) be the parameter ID
192 if (data[index] == 02 && data[index + 1] == 01) {
193 pace_info->parameter_id = data[index + 2];
194 index += 3;
195 }
196 }
197 else {
198 // skip this OID
199 index += 2 + data[index + 1];
200 }
201 }
202 // if the length is 0, something is wrong
203 // TODO: This needs to be extended to support long tags
204 else if (data[index + 1] == 0) {
205 return index;
206 }
207 else {
208 // skip this part
209 // TODO: This needs to be extended to support long tags
210 // TODO: This needs to be extended to support unknown elements with
211 // a size > 0x7F
212 index += 2 + data[index + 1];
213 }
214 }
215
216 // TODO: We should check whether we reached the end in error, but for that
217 // we need a better parser (e.g. with states like IN_SET or IN_PACE_INFO)
218 return 0;
219 }
220
221 //-----------------------------------------------------------------------------
222 // Read the file EF.CardAccess and save it into a buffer (at most max_length bytes)
223 // Returns -1 on failure or the length of the data on success
224 // TODO: for the moment this sends only 1 APDU regardless of the requested length
225 //-----------------------------------------------------------------------------
226 int EPA_Read_CardAccess(uint8_t *buffer, size_t max_length)
227 {
228 // the response APDU of the card
229 // since the card doesn't always care for the expected length we send it,
230 // we reserve 262 bytes here just to be safe (256-byte APDU + SW + ISO frame)
231 uint8_t response_apdu[262];
232 int rapdu_length = 0;
233
234 // select the file EF.CardAccess
235 rapdu_length = EPA_APDU((uint8_t *)apdu_select_binary_cardaccess,
236 sizeof(apdu_select_binary_cardaccess),
237 response_apdu);
238 if (rapdu_length < 6
239 || response_apdu[rapdu_length - 4] != 0x90
240 || response_apdu[rapdu_length - 3] != 0x00)
241 {
242 DbpString("Failed to select EF.CardAccess!");
243 return -1;
244 }
245
246 // read the file
247 rapdu_length = EPA_APDU((uint8_t *)apdu_read_binary,
248 sizeof(apdu_read_binary),
249 response_apdu);
250 if (rapdu_length <= 6
251 || response_apdu[rapdu_length - 4] != 0x90
252 || response_apdu[rapdu_length - 3] != 0x00)
253 {
254 Dbprintf("Failed to read EF.CardAccess!");
255 return -1;
256 }
257
258 // copy the content into the buffer
259 // length of data available: apdu_length - 4 (ISO frame) - 2 (SW)
260 size_t to_copy = rapdu_length - 6;
261 to_copy = to_copy < max_length ? to_copy : max_length;
262 memcpy(buffer, response_apdu+2, to_copy);
263 return to_copy;
264 }
265
266 //-----------------------------------------------------------------------------
267 // Abort helper function for EPA_PACE_Collect_Nonce
268 // sets relevant data in ack, sends the response
269 //-----------------------------------------------------------------------------
270 static void EPA_PACE_Collect_Nonce_Abort(uint8_t step, int func_return)
271 {
272 // power down the field
273 EPA_Finish();
274
275 // send the USB packet
276 cmd_send(CMD_ACK,step,func_return,0,0,0);
277 }
278
279 //-----------------------------------------------------------------------------
280 // Acquire one encrypted PACE nonce
281 //-----------------------------------------------------------------------------
282 void EPA_PACE_Collect_Nonce(UsbCommand *c)
283 {
284 /*
285 * ack layout:
286 * arg:
287 * 1. element
288 * step where the error occured or 0 if no error occured
289 * 2. element
290 * return code of the last executed function
291 * d:
292 * Encrypted nonce
293 */
294
295 // return value of a function
296 int func_return = 0;
297
298 // set up communication
299 func_return = EPA_Setup();
300 if (func_return != 0) {
301 EPA_PACE_Collect_Nonce_Abort(1, func_return);
302 return;
303 }
304
305 // read the CardAccess file
306 // this array will hold the CardAccess file
307 uint8_t card_access[256] = {0};
308 int card_access_length = EPA_Read_CardAccess(card_access, 256);
309 // the response has to be at least this big to hold the OID
310 if (card_access_length < 18) {
311 EPA_PACE_Collect_Nonce_Abort(2, card_access_length);
312 return;
313 }
314
315 // this will hold the PACE info of the card
316 pace_version_info_t pace_version_info;
317 // search for the PACE OID
318 func_return = EPA_Parse_CardAccess(card_access,
319 card_access_length,
320 &pace_version_info);
321 if (func_return != 0 || pace_version_info.version == 0) {
322 EPA_PACE_Collect_Nonce_Abort(3, func_return);
323 return;
324 }
325
326 // initiate the PACE protocol
327 // use the CAN for the password since that doesn't change
328 func_return = EPA_PACE_MSE_Set_AT(pace_version_info, 2);
329
330 // now get the nonce
331 uint8_t nonce[256] = {0};
332 uint8_t requested_size = (uint8_t)c->arg[0];
333 func_return = EPA_PACE_Get_Nonce(requested_size, nonce);
334 // check if the command succeeded
335 if (func_return < 0)
336 {
337 EPA_PACE_Collect_Nonce_Abort(4, func_return);
338 return;
339 }
340
341 // all done, return
342 EPA_Finish();
343
344 // save received information
345 cmd_send(CMD_ACK,0,func_return,0,nonce,func_return);
346 }
347
348 //-----------------------------------------------------------------------------
349 // Performs the "Get Nonce" step of the PACE protocol and saves the returned
350 // nonce. The caller is responsible for allocating enough memory to store the
351 // nonce. Note that the returned size might be less or than or greater than the
352 // requested size!
353 // Returns the actual size of the nonce on success or a less-than-zero error
354 // code on failure.
355 //-----------------------------------------------------------------------------
356 int EPA_PACE_Get_Nonce(uint8_t requested_length, uint8_t *nonce)
357 {
358 // build the APDU
359 uint8_t apdu[sizeof(apdu_general_authenticate_pace_get_nonce) + 1];
360 // copy the constant part
361 memcpy(apdu,
362 apdu_general_authenticate_pace_get_nonce,
363 sizeof(apdu_general_authenticate_pace_get_nonce));
364 // append Le (requested length + 2 due to tag/length taking 2 bytes) in RAPDU
365 apdu[sizeof(apdu_general_authenticate_pace_get_nonce)] = requested_length + 4;
366
367 // send it
368 uint8_t response_apdu[262];
369 int send_return = EPA_APDU(apdu,
370 sizeof(apdu),
371 response_apdu);
372 // check if the command succeeded
373 if (send_return < 6
374 || response_apdu[send_return - 4] != 0x90
375 || response_apdu[send_return - 3] != 0x00)
376 {
377 return -1;
378 }
379
380 // if there is no nonce in the RAPDU, return here
381 if (send_return < 10)
382 {
383 // no error
384 return 0;
385 }
386 // get the actual length of the nonce
387 uint8_t nonce_length = response_apdu[5];
388 if (nonce_length > send_return - 10)
389 {
390 nonce_length = send_return - 10;
391 }
392 // copy the nonce
393 memcpy(nonce, response_apdu + 6, nonce_length);
394
395 return nonce_length;
396 }
397
398 //-----------------------------------------------------------------------------
399 // Initializes the PACE protocol by performing the "MSE: Set AT" step
400 // Returns 0 on success or a non-zero error code on failure
401 //-----------------------------------------------------------------------------
402 int EPA_PACE_MSE_Set_AT(pace_version_info_t pace_version_info, uint8_t password)
403 {
404 // create the MSE: Set AT APDU
405 uint8_t apdu[23];
406 // the minimum length (will be increased as more data is added)
407 size_t apdu_length = 20;
408 // copy the constant part
409 memcpy(apdu,
410 apdu_mse_set_at_start,
411 sizeof(apdu_mse_set_at_start));
412 // type: OID
413 apdu[5] = 0x80;
414 // length of the OID
415 apdu[6] = sizeof(pace_version_info.oid);
416 // copy the OID
417 memcpy(apdu + 7,
418 pace_version_info.oid,
419 sizeof(pace_version_info.oid));
420 // type: password
421 apdu[17] = 0x83;
422 // length: 1
423 apdu[18] = 1;
424 // password
425 apdu[19] = password;
426 // if standardized domain parameters are used, copy the ID
427 if (pace_version_info.parameter_id != 0) {
428 apdu_length += 3;
429 // type: domain parameter
430 apdu[20] = 0x84;
431 // length: 1
432 apdu[21] = 1;
433 // copy the parameter ID
434 apdu[22] = pace_version_info.parameter_id;
435 }
436 // now set Lc to the actual length
437 apdu[4] = apdu_length - 5;
438 // send it
439 uint8_t response_apdu[6];
440 int send_return = EPA_APDU(apdu,
441 apdu_length,
442 response_apdu);
443 // check if the command succeeded
444 if (send_return != 6
445 || response_apdu[send_return - 4] != 0x90
446 || response_apdu[send_return - 3] != 0x00)
447 {
448 return 1;
449 }
450 return 0;
451 }
452
453 //-----------------------------------------------------------------------------
454 // Perform the PACE protocol by replaying given APDUs
455 //-----------------------------------------------------------------------------
456 void EPA_PACE_Replay(UsbCommand *c)
457 {
458 uint32_t timings[sizeof(apdu_lengths_replay) / sizeof(apdu_lengths_replay[0])] = {0};
459
460 // if an APDU has been passed, save it
461 if (c->arg[0] != 0) {
462 // make sure it's not too big
463 if(c->arg[2] > apdus_replay[c->arg[0] - 1].len)
464 {
465 cmd_send(CMD_ACK, 1, 0, 0, NULL, 0);
466 }
467 memcpy(apdus_replay[c->arg[0] - 1].data + c->arg[1],
468 c->d.asBytes,
469 c->arg[2]);
470 // save/update APDU length
471 if (c->arg[1] == 0) {
472 apdu_lengths_replay[c->arg[0] - 1] = c->arg[2];
473 } else {
474 apdu_lengths_replay[c->arg[0] - 1] += c->arg[2];
475 }
476 cmd_send(CMD_ACK, 0, 0, 0, NULL, 0);
477 return;
478 }
479
480 // return value of a function
481 int func_return;
482
483 // set up communication
484 func_return = EPA_Setup();
485 if (func_return != 0) {
486 EPA_Finish();
487 cmd_send(CMD_ACK, 2, func_return, 0, NULL, 0);
488 return;
489 }
490
491 // response APDU
492 uint8_t response_apdu[300] = {0};
493
494 // now replay the data and measure the timings
495 for (int i = 0; i < sizeof(apdu_lengths_replay); i++) {
496 StartCountUS();
497 func_return = EPA_APDU(apdus_replay[i].data,
498 apdu_lengths_replay[i],
499 response_apdu);
500 timings[i] = GetCountUS();
501 // every step but the last one should succeed
502 if (i < sizeof(apdu_lengths_replay) - 1
503 && (func_return < 6
504 || response_apdu[func_return - 4] != 0x90
505 || response_apdu[func_return - 3] != 0x00))
506 {
507 EPA_Finish();
508 cmd_send(CMD_ACK, 3 + i, func_return, 0, timings, 20);
509 return;
510 }
511 }
512 EPA_Finish();
513 cmd_send(CMD_ACK,0,0,0,timings,20);
514 return;
515 }
516
517 //-----------------------------------------------------------------------------
518 // Set up a communication channel (Card Select, PPS)
519 // Returns 0 on success or a non-zero error code on failure
520 //-----------------------------------------------------------------------------
521 int EPA_Setup()
522 {
523 int return_code = 0;
524 uint8_t uid[10];
525 uint8_t pps_response[3];
526 uint8_t pps_response_par[1];
527 iso14a_card_select_t card_select_info;
528
529 // first, look for type A cards
530 // power up the field
531 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
532 // select the card
533 return_code = iso14443a_select_card(uid, &card_select_info, NULL, true, 0, false);
534 if (return_code == 1) {
535 // send the PPS request
536 ReaderTransmit((uint8_t *)pps, sizeof(pps), NULL);
537 return_code = ReaderReceive(pps_response, pps_response_par);
538 if (return_code != 3 || pps_response[0] != 0xD0) {
539 return return_code == 0 ? 2 : return_code;
540 }
541 Dbprintf("ISO 14443 Type A");
542 iso_type = 'a';
543 return 0;
544 }
545
546 // if we're here, there is no type A card, so we look for type B
547 // power up the field
548 iso14443b_setup();
549 // select the card
550 return_code = iso14443b_select_card();
551 if (return_code == 1) {
552 Dbprintf("ISO 14443 Type B");
553 iso_type = 'b';
554 return 0;
555 }
556 Dbprintf("No card found.");
557 return 1;
558 }
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