05de928ebc03c56dc4604f8945b653019acd22dc
[proxmark3-svn] / client / emv / tlv.c
1 /*
2 * libopenemv - a library to work with EMV family of smart cards
3 * Copyright (C) 2012, 2015 Dmitry Eremin-Solenikov
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * https://github.com/lumag/emv-tools/blob/master/lib/tlv.c
16 */
17
18 #ifdef HAVE_CONFIG_H
19 #include <config.h>
20 #endif
21
22 #include "tlv.h"
23
24 #include <string.h>
25 #include <stdint.h>
26 #include <stddef.h>
27 #include <stdlib.h>
28
29 #define TLV_TAG_CLASS_MASK 0xc0
30 #define TLV_TAG_COMPLEX 0x20
31 #define TLV_TAG_VALUE_MASK 0x1f
32 #define TLV_TAG_VALUE_CONT 0x1f
33 #define TLV_TAG_INVALID 0
34
35 #define TLV_LEN_LONG 0x80
36 #define TLV_LEN_MASK 0x7f
37 #define TLV_LEN_INVALID (~0)
38
39 // http://radek.io/2012/11/10/magical-container_of-macro/
40 //#define container_of(ptr, type, member) ({
41 // const typeof( ((type *)0)->member ) *__mptr = (ptr);
42 // (type *)( (char *)__mptr - offsetof(type,member) );})
43
44 struct tlvdb {
45 struct tlv tag;
46 struct tlvdb *next;
47 struct tlvdb *parent;
48 struct tlvdb *children;
49 };
50
51 struct tlvdb_root {
52 struct tlvdb db;
53 size_t len;
54 unsigned char buf[0];
55 };
56
57 static tlv_tag_t tlv_parse_tag(const unsigned char **buf, size_t *len)
58 {
59 tlv_tag_t tag;
60
61 if (*len == 0)
62 return TLV_TAG_INVALID;
63 tag = **buf;
64 --*len;
65 ++*buf;
66 if ((tag & TLV_TAG_VALUE_MASK) != TLV_TAG_VALUE_CONT)
67 return tag;
68
69 if (*len == 0)
70 return TLV_TAG_INVALID;
71
72 tag <<= 8;
73 tag |= **buf;
74 --*len;
75 ++*buf;
76
77 return tag;
78 }
79
80 static size_t tlv_parse_len(const unsigned char **buf, size_t *len)
81 {
82 size_t l;
83
84 if (*len == 0)
85 return TLV_LEN_INVALID;
86
87 l = **buf;
88 --*len;
89 ++*buf;
90
91 if (!(l & TLV_LEN_LONG))
92 return l;
93
94 size_t ll = l &~ TLV_LEN_LONG;
95 if (ll > 5)
96 return TLV_LEN_INVALID;
97
98 l = 0;
99 for (int i = 1; i <= ll; i++) {
100 l = (l << 8) + **buf;
101 --*len;
102 ++*buf;
103 }
104
105 return l;
106 }
107
108 bool tlv_parse_tl(const unsigned char **buf, size_t *len, struct tlv *tlv)
109 {
110 tlv->value = 0;
111
112 tlv->tag = tlv_parse_tag(buf, len);
113 if (tlv->tag == TLV_TAG_INVALID)
114 return false;
115
116 tlv->len = tlv_parse_len(buf, len);
117 if (tlv->len == TLV_LEN_INVALID)
118 return false;
119
120 return true;
121 }
122
123 static struct tlvdb *tlvdb_parse_children(struct tlvdb *parent);
124
125 static bool tlvdb_parse_one(struct tlvdb *tlvdb,
126 struct tlvdb *parent,
127 const unsigned char **tmp,
128 size_t *left)
129 {
130 tlvdb->next = tlvdb->children = NULL;
131 tlvdb->parent = parent;
132
133 tlvdb->tag.tag = tlv_parse_tag(tmp, left);
134 if (tlvdb->tag.tag == TLV_TAG_INVALID)
135 goto err;
136
137 tlvdb->tag.len = tlv_parse_len(tmp, left);
138 if (tlvdb->tag.len == TLV_LEN_INVALID)
139 goto err;
140
141 if (tlvdb->tag.len > *left)
142 goto err;
143
144 tlvdb->tag.value = *tmp;
145
146 *tmp += tlvdb->tag.len;
147 *left -= tlvdb->tag.len;
148
149 if (tlv_is_constructed(&tlvdb->tag) && (tlvdb->tag.len != 0)) {
150 tlvdb->children = tlvdb_parse_children(tlvdb);
151 if (!tlvdb->children)
152 goto err;
153 } else {
154 tlvdb->children = NULL;
155 }
156
157 return true;
158
159 err:
160 return false;
161 }
162
163 static struct tlvdb *tlvdb_parse_children(struct tlvdb *parent)
164 {
165 const unsigned char *tmp = parent->tag.value;
166 size_t left = parent->tag.len;
167 struct tlvdb *tlvdb, *first = NULL, *prev = NULL;
168
169 while (left != 0) {
170 tlvdb = malloc(sizeof(*tlvdb));
171 if (prev)
172 prev->next = tlvdb;
173 else
174 first = tlvdb;
175 prev = tlvdb;
176
177 if (!tlvdb_parse_one(tlvdb, parent, &tmp, &left))
178 goto err;
179
180 tlvdb->parent = parent;
181 }
182
183 return first;
184
185 err:
186 tlvdb_free(first);
187
188 return NULL;
189 }
190
191 struct tlvdb *tlvdb_parse(const unsigned char *buf, size_t len)
192 {
193 struct tlvdb_root *root;
194 const unsigned char *tmp;
195 size_t left;
196
197 if (!len || !buf)
198 return NULL;
199
200 root = malloc(sizeof(*root) + len);
201 root->len = len;
202 memcpy(root->buf, buf, len);
203
204 tmp = root->buf;
205 left = len;
206
207 if (!tlvdb_parse_one(&root->db, NULL, &tmp, &left))
208 goto err;
209
210 if (left)
211 goto err;
212
213 return &root->db;
214
215 err:
216 tlvdb_free(&root->db);
217
218 return NULL;
219 }
220
221 struct tlvdb *tlvdb_parse_multi(const unsigned char *buf, size_t len)
222 {
223 struct tlvdb_root *root;
224 const unsigned char *tmp;
225 size_t left;
226
227 if (!len || !buf)
228 return NULL;
229
230 root = malloc(sizeof(*root) + len);
231 root->len = len;
232 memcpy(root->buf, buf, len);
233
234 tmp = root->buf;
235 left = len;
236
237 if (!tlvdb_parse_one(&root->db, NULL, &tmp, &left))
238 goto err;
239
240 while (left != 0) {
241 struct tlvdb *db = malloc(sizeof(*db));
242 if (!tlvdb_parse_one(db, NULL, &tmp, &left)) {
243 free (db);
244 goto err;
245 }
246
247 tlvdb_add(&root->db, db);
248 }
249
250 return &root->db;
251
252 err:
253 tlvdb_free(&root->db);
254
255 return NULL;
256 }
257
258 struct tlvdb *tlvdb_fixed(tlv_tag_t tag, size_t len, const unsigned char *value)
259 {
260 struct tlvdb_root *root = malloc(sizeof(*root) + len);
261
262 root->len = len;
263 memcpy(root->buf, value, len);
264
265 root->db.parent = root->db.next = root->db.children = NULL;
266 root->db.tag.tag = tag;
267 root->db.tag.len = len;
268 root->db.tag.value = root->buf;
269
270 return &root->db;
271 }
272
273 struct tlvdb *tlvdb_external(tlv_tag_t tag, size_t len, const unsigned char *value)
274 {
275 struct tlvdb_root *root = malloc(sizeof(*root));
276
277 root->len = 0;
278
279 root->db.parent = root->db.next = root->db.children = NULL;
280 root->db.tag.tag = tag;
281 root->db.tag.len = len;
282 root->db.tag.value = value;
283
284 return &root->db;
285 }
286
287 void tlvdb_free(struct tlvdb *tlvdb)
288 {
289 struct tlvdb *next = NULL;
290
291 if (!tlvdb)
292 return;
293
294 for (; tlvdb; tlvdb = next) {
295 next = tlvdb->next;
296 tlvdb_free(tlvdb->children);
297 free(tlvdb);
298 }
299 }
300
301 struct tlvdb *tlvdb_find_next(struct tlvdb *tlvdb, tlv_tag_t tag) {
302 if (!tlvdb)
303 return NULL;
304
305 return tlvdb_find(tlvdb->next, tag);
306 }
307
308 struct tlvdb *tlvdb_find(struct tlvdb *tlvdb, tlv_tag_t tag) {
309 if (!tlvdb)
310 return NULL;
311
312 for (; tlvdb; tlvdb = tlvdb->next) {
313 if (tlvdb->tag.tag == tag)
314 return tlvdb;
315 }
316
317 return NULL;
318 }
319
320 struct tlvdb *tlvdb_find_full(struct tlvdb *tlvdb, tlv_tag_t tag) {
321 if (!tlvdb)
322 return NULL;
323
324 for (; tlvdb; tlvdb = tlvdb->next) {
325 if (tlvdb->tag.tag == tag)
326 return tlvdb;
327
328 if (tlvdb->children) {
329 struct tlvdb * ch = tlvdb_find_full(tlvdb->children, tag);
330 if (ch)
331 return ch;
332 }
333 }
334
335 return NULL;
336 }
337
338 struct tlvdb *tlvdb_find_path(struct tlvdb *tlvdb, tlv_tag_t tag[]) {
339 int i = 0;
340 struct tlvdb *tnext = tlvdb;
341
342 while (tnext && tag[i]) {
343 tnext = tlvdb_find(tnext, tag[i]);
344 i++;
345 if (tag[i] && tnext) {
346 tnext = tnext->children;
347 }
348 }
349
350 return tnext;
351 }
352
353 void tlvdb_add(struct tlvdb *tlvdb, struct tlvdb *other)
354 {
355 if (tlvdb == other)
356 return;
357
358 while (tlvdb->next) {
359 if (tlvdb->next == other)
360 return;
361
362 tlvdb = tlvdb->next;
363 }
364
365 tlvdb->next = other;
366 }
367
368 void tlvdb_change_or_add_node_ex(struct tlvdb *tlvdb, tlv_tag_t tag, size_t len, const unsigned char *value, struct tlvdb **tlvdb_elm)
369 {
370 struct tlvdb *telm = tlvdb_find_full(tlvdb, tag);
371 if (telm == NULL) {
372 // new tlv element
373 struct tlvdb *elm = tlvdb_fixed(tag, len, value);
374 tlvdb_add(tlvdb, elm);
375 if (tlvdb_elm)
376 *tlvdb_elm = elm;
377 } else {
378 // the same tlv structure
379 if (telm->tag.tag == tag && telm->tag.len == len && !memcmp(telm->tag.value, value, len))
380 return;
381
382 // replace tlv element
383 struct tlvdb *tnewelm = tlvdb_fixed(tag, len, value);
384 tnewelm->next = telm->next;
385 tnewelm->parent = telm->parent;
386
387 // if telm stayed first in children chain
388 if (telm->parent && telm->parent->children == telm) {
389 telm->parent->children = tnewelm;
390 }
391
392 // if telm have previous element
393 if (telm != tlvdb) {
394 // elm in root
395 struct tlvdb *celm = tlvdb;
396 // elm in child list of node
397 if (telm->parent && telm->parent->children)
398 celm = telm->parent->children;
399
400 // find previous element
401 for (; celm; celm = celm->next) {
402 if (celm->next == telm) {
403 celm->next = tnewelm;
404 break;
405 }
406 }
407 }
408
409 // free old element with childrens
410 telm->next = NULL;
411 tlvdb_free(telm);
412
413 if (tlvdb_elm)
414 *tlvdb_elm = tnewelm;
415 }
416
417 return;
418 }
419
420 void tlvdb_change_or_add_node(struct tlvdb *tlvdb, tlv_tag_t tag, size_t len, const unsigned char *value)
421 {
422 tlvdb_change_or_add_node_ex(tlvdb, tag, len, value, NULL);
423 }
424
425 void tlvdb_visit(const struct tlvdb *tlvdb, tlv_cb cb, void *data, int level)
426 {
427 struct tlvdb *next = NULL;
428
429 if (!tlvdb)
430 return;
431
432 for (; tlvdb; tlvdb = next) {
433 next = tlvdb->next;
434 cb(data, &tlvdb->tag, level, (tlvdb->children == NULL));
435 tlvdb_visit(tlvdb->children, cb, data, level + 1);
436 }
437 }
438
439 static const struct tlvdb *tlvdb_next(const struct tlvdb *tlvdb)
440 {
441 if (tlvdb->children)
442 return tlvdb->children;
443
444 while (tlvdb) {
445 if (tlvdb->next)
446 return tlvdb->next;
447
448 tlvdb = tlvdb->parent;
449 }
450
451 return NULL;
452 }
453
454 const struct tlv *tlvdb_get(const struct tlvdb *tlvdb, tlv_tag_t tag, const struct tlv *prev)
455 {
456 if (prev) {
457 // tlvdb = tlvdb_next(container_of(prev, struct tlvdb, tag));
458 tlvdb = tlvdb_next((struct tlvdb *)prev);
459 }
460
461
462 while (tlvdb) {
463 if (tlvdb->tag.tag == tag)
464 return &tlvdb->tag;
465
466 tlvdb = tlvdb_next(tlvdb);
467 }
468
469 return NULL;
470 }
471
472 const struct tlv *tlvdb_get_inchild(const struct tlvdb *tlvdb, tlv_tag_t tag, const struct tlv *prev) {
473 tlvdb = tlvdb->children;
474 return tlvdb_get(tlvdb, tag, prev);
475 }
476
477 const struct tlv *tlvdb_get_tlv(const struct tlvdb *tlvdb) {
478 return &tlvdb->tag;
479 }
480
481 unsigned char *tlv_encode(const struct tlv *tlv, size_t *len)
482 {
483 size_t size = tlv->len;
484 unsigned char *data;
485 size_t pos;
486
487 if (tlv->tag > 0x100)
488 size += 2;
489 else
490 size += 1;
491
492 if (tlv->len > 0x7f)
493 size += 2;
494 else
495 size += 1;
496
497 data = malloc(size);
498 if (!data) {
499 *len = 0;
500 return NULL;
501 }
502
503 pos = 0;
504
505 if (tlv->tag > 0x100) {
506 data[pos++] = tlv->tag >> 8;
507 data[pos++] = tlv->tag & 0xff;
508 } else
509 data[pos++] = tlv->tag;
510
511 if (tlv->len > 0x7f) {
512 data[pos++] = 0x81;
513 data[pos++] = tlv->len;
514 } else
515 data[pos++] = tlv->len;
516
517 memcpy(data + pos, tlv->value, tlv->len);
518 pos += tlv->len;
519
520 *len = pos;
521 return data;
522 }
523
524 bool tlv_is_constructed(const struct tlv *tlv)
525 {
526 return (tlv->tag < 0x100 ? tlv->tag : tlv->tag >> 8) & TLV_TAG_COMPLEX;
527 }
528
529 bool tlv_equal(const struct tlv *a, const struct tlv *b)
530 {
531 if (!a && !b)
532 return true;
533
534 if (!a || !b)
535 return false;
536
537 return a->tag == b->tag && a->len == b->len && !memcmp(a->value, b->value, a->len);
538 }
539
540 struct tlvdb *tlvdb_elm_get_next(struct tlvdb *tlvdb)
541 {
542 return tlvdb->next;
543 }
544
545 struct tlvdb *tlvdb_elm_get_children(struct tlvdb *tlvdb)
546 {
547 return tlvdb->children;
548 }
549
550 struct tlvdb *tlvdb_elm_get_parent(struct tlvdb *tlvdb)
551 {
552 return tlvdb->parent;
553 }
554
555 bool tlv_get_uint8(const struct tlv *etlv, uint8_t *value)
556 {
557 *value = 0;
558 if (etlv)
559 {
560 if (etlv->len == 0)
561 return true;
562
563 if (etlv->len == 1)
564 {
565 *value = etlv->value[0];
566 return true;
567 }
568 }
569 return false;
570 }
571
572 bool tlv_get_int(const struct tlv *etlv, int *value)
573 {
574 *value = 0;
575 if (etlv)
576 {
577 if (etlv->len == 0)
578 return true;
579
580 if (etlv->len <= 4)
581 {
582 for (int i = 0; i < etlv->len; i++)
583 {
584 *value += etlv->value[i] * (1 << (i * 8));
585 }
586 return true;
587 }
588 }
589 return false;
590 }
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