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12#define pr_fmt(fmt) "PKCS7: "fmt
13#include <linux/kernel.h>
14#include <linux/export.h>
15#include <linux/slab.h>
16#include <linux/err.h>
17#include <linux/oid_registry.h>
18#include <crypto/public_key.h>
19#include "pkcs7_parser.h"
20#include "pkcs7-asn1.h"
21
22struct pkcs7_parse_context {
23 struct pkcs7_message *msg;
24 struct pkcs7_signed_info *sinfo;
25 struct pkcs7_signed_info **ppsinfo;
26 struct x509_certificate *certs;
27 struct x509_certificate **ppcerts;
28 unsigned long data;
29 enum OID last_oid;
30 unsigned x509_index;
31 unsigned sinfo_index;
32 const void *raw_serial;
33 unsigned raw_serial_size;
34 unsigned raw_issuer_size;
35 const void *raw_issuer;
36 const void *raw_skid;
37 unsigned raw_skid_size;
38 bool expect_skid;
39};
40
41
42
43
44static void pkcs7_free_signed_info(struct pkcs7_signed_info *sinfo)
45{
46 if (sinfo) {
47 public_key_signature_free(sinfo->sig);
48 kfree(sinfo);
49 }
50}
51
52
53
54
55
56void pkcs7_free_message(struct pkcs7_message *pkcs7)
57{
58 struct x509_certificate *cert;
59 struct pkcs7_signed_info *sinfo;
60
61 if (pkcs7) {
62 while (pkcs7->certs) {
63 cert = pkcs7->certs;
64 pkcs7->certs = cert->next;
65 x509_free_certificate(cert);
66 }
67 while (pkcs7->crl) {
68 cert = pkcs7->crl;
69 pkcs7->crl = cert->next;
70 x509_free_certificate(cert);
71 }
72 while (pkcs7->signed_infos) {
73 sinfo = pkcs7->signed_infos;
74 pkcs7->signed_infos = sinfo->next;
75 pkcs7_free_signed_info(sinfo);
76 }
77 kfree(pkcs7);
78 }
79}
80EXPORT_SYMBOL_GPL(pkcs7_free_message);
81
82
83
84
85static int pkcs7_check_authattrs(struct pkcs7_message *msg)
86{
87 struct pkcs7_signed_info *sinfo;
88 bool want = false;
89
90 sinfo = msg->signed_infos;
91 if (sinfo->authattrs) {
92 want = true;
93 msg->have_authattrs = true;
94 }
95
96 for (sinfo = sinfo->next; sinfo; sinfo = sinfo->next)
97 if (!!sinfo->authattrs != want)
98 goto inconsistent;
99 return 0;
100
101inconsistent:
102 pr_warn("Inconsistently supplied authAttrs\n");
103 return -EINVAL;
104}
105
106
107
108
109
110
111struct pkcs7_message *pkcs7_parse_message(const void *data, size_t datalen)
112{
113 struct pkcs7_parse_context *ctx;
114 struct pkcs7_message *msg = ERR_PTR(-ENOMEM);
115 int ret;
116
117 ctx = kzalloc(sizeof(struct pkcs7_parse_context), GFP_KERNEL);
118 if (!ctx)
119 goto out_no_ctx;
120 ctx->msg = kzalloc(sizeof(struct pkcs7_message), GFP_KERNEL);
121 if (!ctx->msg)
122 goto out_no_msg;
123 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
124 if (!ctx->sinfo)
125 goto out_no_sinfo;
126 ctx->sinfo->sig = kzalloc(sizeof(struct public_key_signature),
127 GFP_KERNEL);
128 if (!ctx->sinfo->sig)
129 goto out_no_sig;
130
131 ctx->data = (unsigned long)data;
132 ctx->ppcerts = &ctx->certs;
133 ctx->ppsinfo = &ctx->msg->signed_infos;
134
135
136 ret = asn1_ber_decoder(&pkcs7_decoder, ctx, data, datalen);
137 if (ret < 0) {
138 msg = ERR_PTR(ret);
139 goto out;
140 }
141
142 ret = pkcs7_check_authattrs(ctx->msg);
143 if (ret < 0)
144 goto out;
145
146 msg = ctx->msg;
147 ctx->msg = NULL;
148
149out:
150 while (ctx->certs) {
151 struct x509_certificate *cert = ctx->certs;
152 ctx->certs = cert->next;
153 x509_free_certificate(cert);
154 }
155out_no_sig:
156 pkcs7_free_signed_info(ctx->sinfo);
157out_no_sinfo:
158 pkcs7_free_message(ctx->msg);
159out_no_msg:
160 kfree(ctx);
161out_no_ctx:
162 return msg;
163}
164EXPORT_SYMBOL_GPL(pkcs7_parse_message);
165
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169
170
171
172
173
174
175
176
177
178
179int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
180 const void **_data, size_t *_data_len,
181 size_t *_headerlen)
182{
183 if (!pkcs7->data)
184 return -ENODATA;
185
186 *_data = pkcs7->data;
187 *_data_len = pkcs7->data_len;
188 if (_headerlen)
189 *_headerlen = pkcs7->data_hdrlen;
190 return 0;
191}
192EXPORT_SYMBOL_GPL(pkcs7_get_content_data);
193
194
195
196
197
198int pkcs7_note_OID(void *context, size_t hdrlen,
199 unsigned char tag,
200 const void *value, size_t vlen)
201{
202 struct pkcs7_parse_context *ctx = context;
203
204 ctx->last_oid = look_up_OID(value, vlen);
205 if (ctx->last_oid == OID__NR) {
206 char buffer[50];
207 sprint_oid(value, vlen, buffer, sizeof(buffer));
208 printk("PKCS7: Unknown OID: [%lu] %s\n",
209 (unsigned long)value - ctx->data, buffer);
210 }
211 return 0;
212}
213
214
215
216
217int pkcs7_sig_note_digest_algo(void *context, size_t hdrlen,
218 unsigned char tag,
219 const void *value, size_t vlen)
220{
221 struct pkcs7_parse_context *ctx = context;
222
223 switch (ctx->last_oid) {
224 case OID_md4:
225 ctx->sinfo->sig->hash_algo = "md4";
226 break;
227 case OID_md5:
228 ctx->sinfo->sig->hash_algo = "md5";
229 break;
230 case OID_sha1:
231 ctx->sinfo->sig->hash_algo = "sha1";
232 break;
233 case OID_sha256:
234 ctx->sinfo->sig->hash_algo = "sha256";
235 break;
236 case OID_sha384:
237 ctx->sinfo->sig->hash_algo = "sha384";
238 break;
239 case OID_sha512:
240 ctx->sinfo->sig->hash_algo = "sha512";
241 break;
242 case OID_sha224:
243 ctx->sinfo->sig->hash_algo = "sha224";
244 break;
245 default:
246 printk("Unsupported digest algo: %u\n", ctx->last_oid);
247 return -ENOPKG;
248 }
249 return 0;
250}
251
252
253
254
255int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
256 unsigned char tag,
257 const void *value, size_t vlen)
258{
259 struct pkcs7_parse_context *ctx = context;
260
261 switch (ctx->last_oid) {
262 case OID_rsaEncryption:
263 ctx->sinfo->sig->pkey_algo = "rsa";
264 break;
265 default:
266 printk("Unsupported pkey algo: %u\n", ctx->last_oid);
267 return -ENOPKG;
268 }
269 return 0;
270}
271
272
273
274
275int pkcs7_check_content_type(void *context, size_t hdrlen,
276 unsigned char tag,
277 const void *value, size_t vlen)
278{
279 struct pkcs7_parse_context *ctx = context;
280
281 if (ctx->last_oid != OID_signed_data) {
282 pr_warn("Only support pkcs7_signedData type\n");
283 return -EINVAL;
284 }
285
286 return 0;
287}
288
289
290
291
292int pkcs7_note_signeddata_version(void *context, size_t hdrlen,
293 unsigned char tag,
294 const void *value, size_t vlen)
295{
296 struct pkcs7_parse_context *ctx = context;
297 unsigned version;
298
299 if (vlen != 1)
300 goto unsupported;
301
302 ctx->msg->version = version = *(const u8 *)value;
303 switch (version) {
304 case 1:
305
306
307
308 break;
309 case 3:
310
311 break;
312 default:
313 goto unsupported;
314 }
315
316 return 0;
317
318unsupported:
319 pr_warn("Unsupported SignedData version\n");
320 return -EINVAL;
321}
322
323
324
325
326int pkcs7_note_signerinfo_version(void *context, size_t hdrlen,
327 unsigned char tag,
328 const void *value, size_t vlen)
329{
330 struct pkcs7_parse_context *ctx = context;
331 unsigned version;
332
333 if (vlen != 1)
334 goto unsupported;
335
336 version = *(const u8 *)value;
337 switch (version) {
338 case 1:
339
340
341
342 if (ctx->msg->version != 1)
343 goto version_mismatch;
344 ctx->expect_skid = false;
345 break;
346 case 3:
347
348 if (ctx->msg->version == 1)
349 goto version_mismatch;
350 ctx->expect_skid = true;
351 break;
352 default:
353 goto unsupported;
354 }
355
356 return 0;
357
358unsupported:
359 pr_warn("Unsupported SignerInfo version\n");
360 return -EINVAL;
361version_mismatch:
362 pr_warn("SignedData-SignerInfo version mismatch\n");
363 return -EBADMSG;
364}
365
366
367
368
369int pkcs7_extract_cert(void *context, size_t hdrlen,
370 unsigned char tag,
371 const void *value, size_t vlen)
372{
373 struct pkcs7_parse_context *ctx = context;
374 struct x509_certificate *x509;
375
376 if (tag != ((ASN1_UNIV << 6) | ASN1_CONS_BIT | ASN1_SEQ)) {
377 pr_debug("Cert began with tag %02x at %lu\n",
378 tag, (unsigned long)ctx - ctx->data);
379 return -EBADMSG;
380 }
381
382
383
384
385
386
387 value -= hdrlen;
388 vlen += hdrlen;
389
390 if (((u8*)value)[1] == 0x80)
391 vlen += 2;
392
393 x509 = x509_cert_parse(value, vlen);
394 if (IS_ERR(x509))
395 return PTR_ERR(x509);
396
397 x509->index = ++ctx->x509_index;
398 pr_debug("Got cert %u for %s\n", x509->index, x509->subject);
399 pr_debug("- fingerprint %*phN\n", x509->id->len, x509->id->data);
400
401 *ctx->ppcerts = x509;
402 ctx->ppcerts = &x509->next;
403 return 0;
404}
405
406
407
408
409int pkcs7_note_certificate_list(void *context, size_t hdrlen,
410 unsigned char tag,
411 const void *value, size_t vlen)
412{
413 struct pkcs7_parse_context *ctx = context;
414
415 pr_devel("Got cert list (%02x)\n", tag);
416
417 *ctx->ppcerts = ctx->msg->certs;
418 ctx->msg->certs = ctx->certs;
419 ctx->certs = NULL;
420 ctx->ppcerts = &ctx->certs;
421 return 0;
422}
423
424
425
426
427int pkcs7_note_content(void *context, size_t hdrlen,
428 unsigned char tag,
429 const void *value, size_t vlen)
430{
431 struct pkcs7_parse_context *ctx = context;
432
433 if (ctx->last_oid != OID_data &&
434 ctx->last_oid != OID_msIndirectData) {
435 pr_warn("Unsupported data type %d\n", ctx->last_oid);
436 return -EINVAL;
437 }
438
439 ctx->msg->data_type = ctx->last_oid;
440 return 0;
441}
442
443
444
445
446
447int pkcs7_note_data(void *context, size_t hdrlen,
448 unsigned char tag,
449 const void *value, size_t vlen)
450{
451 struct pkcs7_parse_context *ctx = context;
452
453 pr_debug("Got data\n");
454
455 ctx->msg->data = value;
456 ctx->msg->data_len = vlen;
457 ctx->msg->data_hdrlen = hdrlen;
458 return 0;
459}
460
461
462
463
464int pkcs7_sig_note_authenticated_attr(void *context, size_t hdrlen,
465 unsigned char tag,
466 const void *value, size_t vlen)
467{
468 struct pkcs7_parse_context *ctx = context;
469 struct pkcs7_signed_info *sinfo = ctx->sinfo;
470 enum OID content_type;
471
472 pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
473
474 switch (ctx->last_oid) {
475 case OID_contentType:
476 if (__test_and_set_bit(sinfo_has_content_type, &sinfo->aa_set))
477 goto repeated;
478 content_type = look_up_OID(value, vlen);
479 if (content_type != ctx->msg->data_type) {
480 pr_warn("Mismatch between global data type (%d) and sinfo %u (%d)\n",
481 ctx->msg->data_type, sinfo->index,
482 content_type);
483 return -EBADMSG;
484 }
485 return 0;
486
487 case OID_signingTime:
488 if (__test_and_set_bit(sinfo_has_signing_time, &sinfo->aa_set))
489 goto repeated;
490
491
492
493 return x509_decode_time(&sinfo->signing_time,
494 hdrlen, tag, value, vlen);
495
496 case OID_messageDigest:
497 if (__test_and_set_bit(sinfo_has_message_digest, &sinfo->aa_set))
498 goto repeated;
499 if (tag != ASN1_OTS)
500 return -EBADMSG;
501 sinfo->msgdigest = value;
502 sinfo->msgdigest_len = vlen;
503 return 0;
504
505 case OID_smimeCapabilites:
506 if (__test_and_set_bit(sinfo_has_smime_caps, &sinfo->aa_set))
507 goto repeated;
508 if (ctx->msg->data_type != OID_msIndirectData) {
509 pr_warn("S/MIME Caps only allowed with Authenticode\n");
510 return -EKEYREJECTED;
511 }
512 return 0;
513
514
515
516
517
518
519
520 case OID_msSpOpusInfo:
521 if (__test_and_set_bit(sinfo_has_ms_opus_info, &sinfo->aa_set))
522 goto repeated;
523 goto authenticode_check;
524 case OID_msStatementType:
525 if (__test_and_set_bit(sinfo_has_ms_statement_type, &sinfo->aa_set))
526 goto repeated;
527 authenticode_check:
528 if (ctx->msg->data_type != OID_msIndirectData) {
529 pr_warn("Authenticode AuthAttrs only allowed with Authenticode\n");
530 return -EKEYREJECTED;
531 }
532
533 return 0;
534 default:
535 return 0;
536 }
537
538repeated:
539
540 pr_warn("Repeated/multivalue AuthAttrs not permitted\n");
541 return -EKEYREJECTED;
542}
543
544
545
546
547int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
548 unsigned char tag,
549 const void *value, size_t vlen)
550{
551 struct pkcs7_parse_context *ctx = context;
552 struct pkcs7_signed_info *sinfo = ctx->sinfo;
553
554 if (!test_bit(sinfo_has_content_type, &sinfo->aa_set) ||
555 !test_bit(sinfo_has_message_digest, &sinfo->aa_set)) {
556 pr_warn("Missing required AuthAttr\n");
557 return -EBADMSG;
558 }
559
560 if (ctx->msg->data_type != OID_msIndirectData &&
561 test_bit(sinfo_has_ms_opus_info, &sinfo->aa_set)) {
562 pr_warn("Unexpected Authenticode AuthAttr\n");
563 return -EBADMSG;
564 }
565
566
567 sinfo->authattrs = value - (hdrlen - 1);
568 sinfo->authattrs_len = vlen + (hdrlen - 1);
569 return 0;
570}
571
572
573
574
575int pkcs7_sig_note_serial(void *context, size_t hdrlen,
576 unsigned char tag,
577 const void *value, size_t vlen)
578{
579 struct pkcs7_parse_context *ctx = context;
580 ctx->raw_serial = value;
581 ctx->raw_serial_size = vlen;
582 return 0;
583}
584
585
586
587
588int pkcs7_sig_note_issuer(void *context, size_t hdrlen,
589 unsigned char tag,
590 const void *value, size_t vlen)
591{
592 struct pkcs7_parse_context *ctx = context;
593 ctx->raw_issuer = value;
594 ctx->raw_issuer_size = vlen;
595 return 0;
596}
597
598
599
600
601int pkcs7_sig_note_skid(void *context, size_t hdrlen,
602 unsigned char tag,
603 const void *value, size_t vlen)
604{
605 struct pkcs7_parse_context *ctx = context;
606
607 pr_devel("SKID: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
608
609 ctx->raw_skid = value;
610 ctx->raw_skid_size = vlen;
611 return 0;
612}
613
614
615
616
617int pkcs7_sig_note_signature(void *context, size_t hdrlen,
618 unsigned char tag,
619 const void *value, size_t vlen)
620{
621 struct pkcs7_parse_context *ctx = context;
622
623 ctx->sinfo->sig->s = kmemdup(value, vlen, GFP_KERNEL);
624 if (!ctx->sinfo->sig->s)
625 return -ENOMEM;
626
627 ctx->sinfo->sig->s_size = vlen;
628 return 0;
629}
630
631
632
633
634int pkcs7_note_signed_info(void *context, size_t hdrlen,
635 unsigned char tag,
636 const void *value, size_t vlen)
637{
638 struct pkcs7_parse_context *ctx = context;
639 struct pkcs7_signed_info *sinfo = ctx->sinfo;
640 struct asymmetric_key_id *kid;
641
642 if (ctx->msg->data_type == OID_msIndirectData && !sinfo->authattrs) {
643 pr_warn("Authenticode requires AuthAttrs\n");
644 return -EBADMSG;
645 }
646
647
648 if (!ctx->expect_skid) {
649 kid = asymmetric_key_generate_id(ctx->raw_serial,
650 ctx->raw_serial_size,
651 ctx->raw_issuer,
652 ctx->raw_issuer_size);
653 } else {
654 kid = asymmetric_key_generate_id(ctx->raw_skid,
655 ctx->raw_skid_size,
656 "", 0);
657 }
658 if (IS_ERR(kid))
659 return PTR_ERR(kid);
660
661 pr_devel("SINFO KID: %u [%*phN]\n", kid->len, kid->len, kid->data);
662
663 sinfo->sig->auth_ids[0] = kid;
664 sinfo->index = ++ctx->sinfo_index;
665 *ctx->ppsinfo = sinfo;
666 ctx->ppsinfo = &sinfo->next;
667 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
668 if (!ctx->sinfo)
669 return -ENOMEM;
670 ctx->sinfo->sig = kzalloc(sizeof(struct public_key_signature),
671 GFP_KERNEL);
672 if (!ctx->sinfo->sig)
673 return -ENOMEM;
674 return 0;
675}
676