1 /* $OpenBSD: pk7_doit.c,v 1.47 2022/05/09 19:19:33 jsing Exp $ */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62
63 #include <openssl/err.h>
64 #include <openssl/objects.h>
65 #include <openssl/x509.h>
66 #include <openssl/x509v3.h>
67
68 #include "evp_locl.h"
69 #include "x509_lcl.h"
70
71 static int add_attribute(STACK_OF(X509_ATTRIBUTE) **sk, int nid, int atrtype,
72 void *value);
73 static ASN1_TYPE *get_attribute(STACK_OF(X509_ATTRIBUTE) *sk, int nid);
74
75 static int
PKCS7_type_is_other(PKCS7 * p7)76 PKCS7_type_is_other(PKCS7* p7)
77 {
78 int isOther = 1;
79
80 int nid = OBJ_obj2nid(p7->type);
81
82 switch (nid ) {
83 case NID_pkcs7_data:
84 case NID_pkcs7_signed:
85 case NID_pkcs7_enveloped:
86 case NID_pkcs7_signedAndEnveloped:
87 case NID_pkcs7_digest:
88 case NID_pkcs7_encrypted:
89 isOther = 0;
90 break;
91 default:
92 isOther = 1;
93 }
94
95 return isOther;
96
97 }
98
99 static ASN1_OCTET_STRING *
PKCS7_get_octet_string(PKCS7 * p7)100 PKCS7_get_octet_string(PKCS7 *p7)
101 {
102 if (PKCS7_type_is_data(p7))
103 return p7->d.data;
104 if (PKCS7_type_is_other(p7) && p7->d.other &&
105 (p7->d.other->type == V_ASN1_OCTET_STRING))
106 return p7->d.other->value.octet_string;
107 return NULL;
108 }
109
110 static int
PKCS7_bio_add_digest(BIO ** pbio,X509_ALGOR * alg)111 PKCS7_bio_add_digest(BIO **pbio, X509_ALGOR *alg)
112 {
113 BIO *btmp;
114 const EVP_MD *md;
115 if ((btmp = BIO_new(BIO_f_md())) == NULL) {
116 PKCS7error(ERR_R_BIO_LIB);
117 goto err;
118 }
119
120 md = EVP_get_digestbyobj(alg->algorithm);
121 if (md == NULL) {
122 PKCS7error(PKCS7_R_UNKNOWN_DIGEST_TYPE);
123 goto err;
124 }
125
126 BIO_set_md(btmp, md);
127 if (*pbio == NULL)
128 *pbio = btmp;
129 else if (!BIO_push(*pbio, btmp)) {
130 PKCS7error(ERR_R_BIO_LIB);
131 goto err;
132 }
133 btmp = NULL;
134
135 return 1;
136
137 err:
138 BIO_free(btmp);
139 return 0;
140
141 }
142
143 static int
pkcs7_encode_rinfo(PKCS7_RECIP_INFO * ri,unsigned char * key,int keylen)144 pkcs7_encode_rinfo(PKCS7_RECIP_INFO *ri, unsigned char *key, int keylen)
145 {
146 EVP_PKEY_CTX *pctx = NULL;
147 EVP_PKEY *pkey = NULL;
148 unsigned char *ek = NULL;
149 int ret = 0;
150 size_t eklen;
151
152 pkey = X509_get_pubkey(ri->cert);
153 if (!pkey)
154 return 0;
155
156 pctx = EVP_PKEY_CTX_new(pkey, NULL);
157 if (!pctx)
158 return 0;
159
160 if (EVP_PKEY_encrypt_init(pctx) <= 0)
161 goto err;
162
163 if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_ENCRYPT,
164 EVP_PKEY_CTRL_PKCS7_ENCRYPT, 0, ri) <= 0) {
165 PKCS7error(PKCS7_R_CTRL_ERROR);
166 goto err;
167 }
168
169 if (EVP_PKEY_encrypt(pctx, NULL, &eklen, key, keylen) <= 0)
170 goto err;
171
172 ek = malloc(eklen);
173
174 if (ek == NULL) {
175 PKCS7error(ERR_R_MALLOC_FAILURE);
176 goto err;
177 }
178
179 if (EVP_PKEY_encrypt(pctx, ek, &eklen, key, keylen) <= 0)
180 goto err;
181
182 ASN1_STRING_set0(ri->enc_key, ek, eklen);
183 ek = NULL;
184
185 ret = 1;
186
187 err:
188 EVP_PKEY_free(pkey);
189 EVP_PKEY_CTX_free(pctx);
190 free(ek);
191 return ret;
192 }
193
194
195 static int
pkcs7_decrypt_rinfo(unsigned char ** pek,int * peklen,PKCS7_RECIP_INFO * ri,EVP_PKEY * pkey,size_t fixlen)196 pkcs7_decrypt_rinfo(unsigned char **pek, int *peklen, PKCS7_RECIP_INFO *ri,
197 EVP_PKEY *pkey, size_t fixlen)
198 {
199 EVP_PKEY_CTX *pctx = NULL;
200 unsigned char *ek = NULL;
201 size_t eklen;
202
203 int ret = -1;
204
205 pctx = EVP_PKEY_CTX_new(pkey, NULL);
206 if (!pctx)
207 return -1;
208
209 if (EVP_PKEY_decrypt_init(pctx) <= 0)
210 goto err;
211
212 if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_DECRYPT,
213 EVP_PKEY_CTRL_PKCS7_DECRYPT, 0, ri) <= 0) {
214 PKCS7error(PKCS7_R_CTRL_ERROR);
215 goto err;
216 }
217
218 if (EVP_PKEY_decrypt(pctx, NULL, &eklen,
219 ri->enc_key->data, ri->enc_key->length) <= 0)
220 goto err;
221
222 ek = malloc(eklen);
223 if (ek == NULL) {
224 PKCS7error(ERR_R_MALLOC_FAILURE);
225 goto err;
226 }
227
228 if (EVP_PKEY_decrypt(pctx, ek, &eklen, ri->enc_key->data,
229 ri->enc_key->length) <= 0 || eklen == 0 ||
230 (fixlen != 0 && eklen != fixlen)) {
231 ret = 0;
232 PKCS7error(ERR_R_EVP_LIB);
233 goto err;
234 }
235
236 ret = 1;
237
238 freezero(*pek, *peklen);
239
240 *pek = ek;
241 *peklen = eklen;
242
243 err:
244 EVP_PKEY_CTX_free(pctx);
245 if (!ret && ek)
246 free(ek);
247
248 return ret;
249 }
250
251 BIO *
PKCS7_dataInit(PKCS7 * p7,BIO * bio)252 PKCS7_dataInit(PKCS7 *p7, BIO *bio)
253 {
254 int i;
255 BIO *out = NULL, *btmp = NULL;
256 X509_ALGOR *xa = NULL;
257 const EVP_CIPHER *evp_cipher = NULL;
258 STACK_OF(X509_ALGOR) *md_sk = NULL;
259 STACK_OF(PKCS7_RECIP_INFO) *rsk = NULL;
260 X509_ALGOR *xalg = NULL;
261 PKCS7_RECIP_INFO *ri = NULL;
262 ASN1_OCTET_STRING *os = NULL;
263
264 if (p7 == NULL) {
265 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
266 return NULL;
267 }
268
269 /*
270 * The content field in the PKCS7 ContentInfo is optional,
271 * but that really only applies to inner content (precisely,
272 * detached signatures).
273 *
274 * When reading content, missing outer content is therefore
275 * treated as an error.
276 *
277 * When creating content, PKCS7_content_new() must be called
278 * before calling this method, so a NULL p7->d is always
279 * an error.
280 */
281 if (p7->d.ptr == NULL) {
282 PKCS7error(PKCS7_R_NO_CONTENT);
283 return NULL;
284 }
285
286 i = OBJ_obj2nid(p7->type);
287 p7->state = PKCS7_S_HEADER;
288
289 switch (i) {
290 case NID_pkcs7_signed:
291 md_sk = p7->d.sign->md_algs;
292 os = PKCS7_get_octet_string(p7->d.sign->contents);
293 break;
294 case NID_pkcs7_signedAndEnveloped:
295 rsk = p7->d.signed_and_enveloped->recipientinfo;
296 md_sk = p7->d.signed_and_enveloped->md_algs;
297 xalg = p7->d.signed_and_enveloped->enc_data->algorithm;
298 evp_cipher = p7->d.signed_and_enveloped->enc_data->cipher;
299 if (evp_cipher == NULL) {
300 PKCS7error(PKCS7_R_CIPHER_NOT_INITIALIZED);
301 goto err;
302 }
303 break;
304 case NID_pkcs7_enveloped:
305 rsk = p7->d.enveloped->recipientinfo;
306 xalg = p7->d.enveloped->enc_data->algorithm;
307 evp_cipher = p7->d.enveloped->enc_data->cipher;
308 if (evp_cipher == NULL) {
309 PKCS7error(PKCS7_R_CIPHER_NOT_INITIALIZED);
310 goto err;
311 }
312 break;
313 case NID_pkcs7_digest:
314 xa = p7->d.digest->md;
315 os = PKCS7_get_octet_string(p7->d.digest->contents);
316 break;
317 case NID_pkcs7_data:
318 break;
319 default:
320 PKCS7error(PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
321 goto err;
322 }
323
324 for (i = 0; i < sk_X509_ALGOR_num(md_sk); i++)
325 if (!PKCS7_bio_add_digest(&out, sk_X509_ALGOR_value(md_sk, i)))
326 goto err;
327
328 if (xa && !PKCS7_bio_add_digest(&out, xa))
329 goto err;
330
331 if (evp_cipher != NULL) {
332 unsigned char key[EVP_MAX_KEY_LENGTH];
333 unsigned char iv[EVP_MAX_IV_LENGTH];
334 int keylen, ivlen;
335 EVP_CIPHER_CTX *ctx;
336
337 if ((btmp = BIO_new(BIO_f_cipher())) == NULL) {
338 PKCS7error(ERR_R_BIO_LIB);
339 goto err;
340 }
341 BIO_get_cipher_ctx(btmp, &ctx);
342 keylen = EVP_CIPHER_key_length(evp_cipher);
343 ivlen = EVP_CIPHER_iv_length(evp_cipher);
344 xalg->algorithm = OBJ_nid2obj(EVP_CIPHER_type(evp_cipher));
345 if (ivlen > 0)
346 arc4random_buf(iv, ivlen);
347 if (EVP_CipherInit_ex(ctx, evp_cipher, NULL, NULL,
348 NULL, 1) <= 0)
349 goto err;
350 if (EVP_CIPHER_CTX_rand_key(ctx, key) <= 0)
351 goto err;
352 if (EVP_CipherInit_ex(ctx, NULL, NULL, key, iv, 1) <= 0)
353 goto err;
354
355 if (ivlen > 0) {
356 if (xalg->parameter == NULL) {
357 xalg->parameter = ASN1_TYPE_new();
358 if (xalg->parameter == NULL)
359 goto err;
360 }
361 if (EVP_CIPHER_param_to_asn1(ctx, xalg->parameter) < 0)
362 goto err;
363 }
364
365 /* Lets do the pub key stuff :-) */
366 for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
367 ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
368 if (pkcs7_encode_rinfo(ri, key, keylen) <= 0)
369 goto err;
370 }
371 explicit_bzero(key, keylen);
372
373 if (out == NULL)
374 out = btmp;
375 else
376 BIO_push(out, btmp);
377 btmp = NULL;
378 }
379
380 if (bio == NULL) {
381 if (PKCS7_is_detached(p7))
382 bio = BIO_new(BIO_s_null());
383 else if (os && os->length > 0)
384 bio = BIO_new_mem_buf(os->data, os->length);
385 if (bio == NULL) {
386 bio = BIO_new(BIO_s_mem());
387 if (bio == NULL)
388 goto err;
389 BIO_set_mem_eof_return(bio, 0);
390 }
391 }
392 if (out)
393 BIO_push(out, bio);
394 else
395 out = bio;
396 bio = NULL;
397 if (0) {
398 err:
399 if (out != NULL)
400 BIO_free_all(out);
401 if (btmp != NULL)
402 BIO_free_all(btmp);
403 out = NULL;
404 }
405 return (out);
406 }
407
408 static int
pkcs7_cmp_ri(PKCS7_RECIP_INFO * ri,X509 * pcert)409 pkcs7_cmp_ri(PKCS7_RECIP_INFO *ri, X509 *pcert)
410 {
411 int ret;
412
413 ret = X509_NAME_cmp(ri->issuer_and_serial->issuer,
414 pcert->cert_info->issuer);
415 if (ret)
416 return ret;
417 return ASN1_INTEGER_cmp(pcert->cert_info->serialNumber,
418 ri->issuer_and_serial->serial);
419 }
420
421 /* int */
422 BIO *
PKCS7_dataDecode(PKCS7 * p7,EVP_PKEY * pkey,BIO * in_bio,X509 * pcert)423 PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
424 {
425 int i, j;
426 BIO *out = NULL, *btmp = NULL, *etmp = NULL, *bio = NULL;
427 X509_ALGOR *xa;
428 ASN1_OCTET_STRING *data_body = NULL;
429 const EVP_MD *evp_md;
430 const EVP_CIPHER *evp_cipher = NULL;
431 EVP_CIPHER_CTX *evp_ctx = NULL;
432 X509_ALGOR *enc_alg = NULL;
433 STACK_OF(X509_ALGOR) *md_sk = NULL;
434 STACK_OF(PKCS7_RECIP_INFO) *rsk = NULL;
435 PKCS7_RECIP_INFO *ri = NULL;
436 unsigned char *ek = NULL, *tkey = NULL;
437 int eklen = 0, tkeylen = 0;
438
439 if (p7 == NULL) {
440 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
441 return NULL;
442 }
443
444 if (p7->d.ptr == NULL) {
445 PKCS7error(PKCS7_R_NO_CONTENT);
446 return NULL;
447 }
448
449 i = OBJ_obj2nid(p7->type);
450 p7->state = PKCS7_S_HEADER;
451
452 switch (i) {
453 case NID_pkcs7_signed:
454 data_body = PKCS7_get_octet_string(p7->d.sign->contents);
455 md_sk = p7->d.sign->md_algs;
456 break;
457 case NID_pkcs7_signedAndEnveloped:
458 rsk = p7->d.signed_and_enveloped->recipientinfo;
459 md_sk = p7->d.signed_and_enveloped->md_algs;
460 data_body = p7->d.signed_and_enveloped->enc_data->enc_data;
461 enc_alg = p7->d.signed_and_enveloped->enc_data->algorithm;
462 evp_cipher = EVP_get_cipherbyobj(enc_alg->algorithm);
463 if (evp_cipher == NULL) {
464 PKCS7error(PKCS7_R_UNSUPPORTED_CIPHER_TYPE);
465 goto err;
466 }
467 break;
468 case NID_pkcs7_enveloped:
469 rsk = p7->d.enveloped->recipientinfo;
470 enc_alg = p7->d.enveloped->enc_data->algorithm;
471 data_body = p7->d.enveloped->enc_data->enc_data;
472 evp_cipher = EVP_get_cipherbyobj(enc_alg->algorithm);
473 if (evp_cipher == NULL) {
474 PKCS7error(PKCS7_R_UNSUPPORTED_CIPHER_TYPE);
475 goto err;
476 }
477 break;
478 default:
479 PKCS7error(PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
480 goto err;
481 }
482
483 /* We will be checking the signature */
484 if (md_sk != NULL) {
485 for (i = 0; i < sk_X509_ALGOR_num(md_sk); i++) {
486 xa = sk_X509_ALGOR_value(md_sk, i);
487 if ((btmp = BIO_new(BIO_f_md())) == NULL) {
488 PKCS7error(ERR_R_BIO_LIB);
489 goto err;
490 }
491
492 j = OBJ_obj2nid(xa->algorithm);
493 evp_md = EVP_get_digestbynid(j);
494 if (evp_md == NULL) {
495 PKCS7error(PKCS7_R_UNKNOWN_DIGEST_TYPE);
496 goto err;
497 }
498
499 BIO_set_md(btmp, evp_md);
500 if (out == NULL)
501 out = btmp;
502 else
503 BIO_push(out, btmp);
504 btmp = NULL;
505 }
506 }
507
508 if (evp_cipher != NULL) {
509 if ((etmp = BIO_new(BIO_f_cipher())) == NULL) {
510 PKCS7error(ERR_R_BIO_LIB);
511 goto err;
512 }
513
514 /* It was encrypted, we need to decrypt the secret key
515 * with the private key */
516
517 /* Find the recipientInfo which matches the passed certificate
518 * (if any)
519 */
520 if (pcert) {
521 for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
522 ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
523 if (!pkcs7_cmp_ri(ri, pcert))
524 break;
525 ri = NULL;
526 }
527 if (ri == NULL) {
528 PKCS7error(PKCS7_R_NO_RECIPIENT_MATCHES_CERTIFICATE);
529 goto err;
530 }
531 }
532
533 /* If we haven't got a certificate try each ri in turn */
534 if (pcert == NULL) {
535 /* Always attempt to decrypt all rinfo even
536 * after sucess as a defence against MMA timing
537 * attacks.
538 */
539 for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
540 ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
541
542 if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey,
543 EVP_CIPHER_key_length(evp_cipher)) < 0)
544 goto err;
545 ERR_clear_error();
546 }
547 } else {
548 /* Only exit on fatal errors, not decrypt failure */
549 if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey, 0) < 0)
550 goto err;
551 ERR_clear_error();
552 }
553
554 evp_ctx = NULL;
555 BIO_get_cipher_ctx(etmp, &evp_ctx);
556 if (EVP_CipherInit_ex(evp_ctx, evp_cipher, NULL, NULL,
557 NULL, 0) <= 0)
558 goto err;
559 if (EVP_CIPHER_asn1_to_param(evp_ctx, enc_alg->parameter) < 0)
560 goto err;
561 /* Generate random key as MMA defence */
562 tkeylen = EVP_CIPHER_CTX_key_length(evp_ctx);
563 tkey = malloc(tkeylen);
564 if (!tkey)
565 goto err;
566 if (EVP_CIPHER_CTX_rand_key(evp_ctx, tkey) <= 0)
567 goto err;
568 if (ek == NULL) {
569 ek = tkey;
570 eklen = tkeylen;
571 tkey = NULL;
572 }
573
574 if (eklen != EVP_CIPHER_CTX_key_length(evp_ctx)) {
575 /* Some S/MIME clients don't use the same key
576 * and effective key length. The key length is
577 * determined by the size of the decrypted RSA key.
578 */
579 if (!EVP_CIPHER_CTX_set_key_length(evp_ctx, eklen)) {
580 /* Use random key as MMA defence */
581 freezero(ek, eklen);
582 ek = tkey;
583 eklen = tkeylen;
584 tkey = NULL;
585 }
586 }
587 /* Clear errors so we don't leak information useful in MMA */
588 ERR_clear_error();
589 if (EVP_CipherInit_ex(evp_ctx, NULL, NULL, ek, NULL, 0) <= 0)
590 goto err;
591
592 freezero(ek, eklen);
593 ek = NULL;
594 freezero(tkey, tkeylen);
595 tkey = NULL;
596
597 if (out == NULL)
598 out = etmp;
599 else
600 BIO_push(out, etmp);
601 etmp = NULL;
602 }
603
604 if (PKCS7_is_detached(p7) || (in_bio != NULL)) {
605 bio = in_bio;
606 } else {
607 if (data_body != NULL && data_body->length > 0)
608 bio = BIO_new_mem_buf(data_body->data, data_body->length);
609 else {
610 bio = BIO_new(BIO_s_mem());
611 BIO_set_mem_eof_return(bio, 0);
612 }
613 if (bio == NULL)
614 goto err;
615 }
616 BIO_push(out, bio);
617
618 if (0) {
619 err:
620 freezero(ek, eklen);
621 freezero(tkey, tkeylen);
622 if (out != NULL)
623 BIO_free_all(out);
624 if (btmp != NULL)
625 BIO_free_all(btmp);
626 if (etmp != NULL)
627 BIO_free_all(etmp);
628 out = NULL;
629 }
630 return (out);
631 }
632
633 static BIO *
PKCS7_find_digest(EVP_MD_CTX ** pmd,BIO * bio,int nid)634 PKCS7_find_digest(EVP_MD_CTX **pmd, BIO *bio, int nid)
635 {
636 for (;;) {
637 bio = BIO_find_type(bio, BIO_TYPE_MD);
638 if (bio == NULL) {
639 PKCS7error(PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
640 return NULL;
641 }
642 BIO_get_md_ctx(bio, pmd);
643 if (*pmd == NULL) {
644 PKCS7error(ERR_R_INTERNAL_ERROR);
645 return NULL;
646 }
647 if (EVP_MD_CTX_type(*pmd) == nid)
648 return bio;
649 bio = BIO_next(bio);
650 }
651 return NULL;
652 }
653
654 static int
do_pkcs7_signed_attrib(PKCS7_SIGNER_INFO * si,EVP_MD_CTX * mctx)655 do_pkcs7_signed_attrib(PKCS7_SIGNER_INFO *si, EVP_MD_CTX *mctx)
656 {
657 unsigned char md_data[EVP_MAX_MD_SIZE];
658 unsigned int md_len;
659
660 /* Add signing time if not already present */
661 if (!PKCS7_get_signed_attribute(si, NID_pkcs9_signingTime)) {
662 if (!PKCS7_add0_attrib_signing_time(si, NULL)) {
663 PKCS7error(ERR_R_MALLOC_FAILURE);
664 return 0;
665 }
666 }
667
668 /* Add digest */
669 if (!EVP_DigestFinal_ex(mctx, md_data, &md_len)) {
670 PKCS7error(ERR_R_EVP_LIB);
671 return 0;
672 }
673 if (!PKCS7_add1_attrib_digest(si, md_data, md_len)) {
674 PKCS7error(ERR_R_MALLOC_FAILURE);
675 return 0;
676 }
677
678 /* Now sign the attributes */
679 if (!PKCS7_SIGNER_INFO_sign(si))
680 return 0;
681
682 return 1;
683 }
684
685
686 int
PKCS7_dataFinal(PKCS7 * p7,BIO * bio)687 PKCS7_dataFinal(PKCS7 *p7, BIO *bio)
688 {
689 int ret = 0;
690 int i, j;
691 BIO *btmp;
692 PKCS7_SIGNER_INFO *si;
693 EVP_MD_CTX *mdc, ctx_tmp;
694 STACK_OF(X509_ATTRIBUTE) *sk;
695 STACK_OF(PKCS7_SIGNER_INFO) *si_sk = NULL;
696 ASN1_OCTET_STRING *os = NULL;
697
698 if (p7 == NULL) {
699 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
700 return 0;
701 }
702
703 if (p7->d.ptr == NULL) {
704 PKCS7error(PKCS7_R_NO_CONTENT);
705 return 0;
706 }
707
708 EVP_MD_CTX_init(&ctx_tmp);
709 i = OBJ_obj2nid(p7->type);
710 p7->state = PKCS7_S_HEADER;
711
712 switch (i) {
713 case NID_pkcs7_data:
714 os = p7->d.data;
715 break;
716 case NID_pkcs7_signedAndEnveloped:
717 /* XXX */
718 si_sk = p7->d.signed_and_enveloped->signer_info;
719 os = p7->d.signed_and_enveloped->enc_data->enc_data;
720 if (!os) {
721 os = ASN1_OCTET_STRING_new();
722 if (!os) {
723 PKCS7error(ERR_R_MALLOC_FAILURE);
724 goto err;
725 }
726 p7->d.signed_and_enveloped->enc_data->enc_data = os;
727 }
728 break;
729 case NID_pkcs7_enveloped:
730 /* XXX */
731 os = p7->d.enveloped->enc_data->enc_data;
732 if (!os) {
733 os = ASN1_OCTET_STRING_new();
734 if (!os) {
735 PKCS7error(ERR_R_MALLOC_FAILURE);
736 goto err;
737 }
738 p7->d.enveloped->enc_data->enc_data = os;
739 }
740 break;
741 case NID_pkcs7_signed:
742 si_sk = p7->d.sign->signer_info;
743 os = PKCS7_get_octet_string(p7->d.sign->contents);
744 if (!PKCS7_is_detached(p7) && os == NULL) {
745 PKCS7error(PKCS7_R_DECODE_ERROR);
746 goto err;
747 }
748 /* If detached data then the content is excluded */
749 if (PKCS7_type_is_data(p7->d.sign->contents) && p7->detached) {
750 ASN1_OCTET_STRING_free(os);
751 os = NULL;
752 p7->d.sign->contents->d.data = NULL;
753 }
754 break;
755
756 case NID_pkcs7_digest:
757 os = PKCS7_get_octet_string(p7->d.digest->contents);
758 if (os == NULL) {
759 PKCS7error(PKCS7_R_DECODE_ERROR);
760 goto err;
761 }
762 /* If detached data then the content is excluded */
763 if (PKCS7_type_is_data(p7->d.digest->contents) &&
764 p7->detached) {
765 ASN1_OCTET_STRING_free(os);
766 os = NULL;
767 p7->d.digest->contents->d.data = NULL;
768 }
769 break;
770
771 default:
772 PKCS7error(PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
773 goto err;
774 }
775
776 if (si_sk != NULL) {
777 for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(si_sk); i++) {
778 si = sk_PKCS7_SIGNER_INFO_value(si_sk, i);
779 if (si->pkey == NULL)
780 continue;
781
782 j = OBJ_obj2nid(si->digest_alg->algorithm);
783
784 if ((btmp = PKCS7_find_digest(&mdc, bio, j)) == NULL)
785 goto err;
786
787 /* We now have the EVP_MD_CTX, lets do the
788 * signing. */
789 if (!EVP_MD_CTX_copy_ex(&ctx_tmp, mdc))
790 goto err;
791
792 sk = si->auth_attr;
793
794 /* If there are attributes, we add the digest
795 * attribute and only sign the attributes */
796 if (sk_X509_ATTRIBUTE_num(sk) > 0) {
797 if (!do_pkcs7_signed_attrib(si, &ctx_tmp))
798 goto err;
799 } else {
800 unsigned char *abuf = NULL;
801 unsigned int abuflen;
802 abuflen = EVP_PKEY_size(si->pkey);
803 abuf = malloc(abuflen);
804 if (!abuf)
805 goto err;
806
807 if (!EVP_SignFinal(&ctx_tmp, abuf, &abuflen,
808 si->pkey)) {
809 PKCS7error(ERR_R_EVP_LIB);
810 goto err;
811 }
812 ASN1_STRING_set0(si->enc_digest, abuf, abuflen);
813 }
814 }
815 } else if (i == NID_pkcs7_digest) {
816 unsigned char md_data[EVP_MAX_MD_SIZE];
817 unsigned int md_len;
818
819 if (!PKCS7_find_digest(&mdc, bio,
820 OBJ_obj2nid(p7->d.digest->md->algorithm)))
821 goto err;
822 if (!EVP_DigestFinal_ex(mdc, md_data, &md_len))
823 goto err;
824 if (ASN1_STRING_set(p7->d.digest->digest, md_data,
825 md_len) == 0)
826 goto err;
827 }
828
829 if (!PKCS7_is_detached(p7)) {
830 /*
831 * NOTE: only reach os == NULL here because detached
832 * digested data support is broken?
833 */
834 if (os == NULL)
835 goto err;
836 if (!(os->flags & ASN1_STRING_FLAG_NDEF)) {
837 char *cont;
838 long contlen;
839
840 btmp = BIO_find_type(bio, BIO_TYPE_MEM);
841 if (btmp == NULL) {
842 PKCS7error(PKCS7_R_UNABLE_TO_FIND_MEM_BIO);
843 goto err;
844 }
845 contlen = BIO_get_mem_data(btmp, &cont);
846 /*
847 * Mark the BIO read only then we can use its copy
848 * of the data instead of making an extra copy.
849 */
850 BIO_set_flags(btmp, BIO_FLAGS_MEM_RDONLY);
851 BIO_set_mem_eof_return(btmp, 0);
852 ASN1_STRING_set0(os, (unsigned char *)cont, contlen);
853 }
854 }
855 ret = 1;
856 err:
857 EVP_MD_CTX_cleanup(&ctx_tmp);
858 return (ret);
859 }
860
861 int
PKCS7_SIGNER_INFO_sign(PKCS7_SIGNER_INFO * si)862 PKCS7_SIGNER_INFO_sign(PKCS7_SIGNER_INFO *si)
863 {
864 EVP_MD_CTX mctx;
865 EVP_PKEY_CTX *pctx;
866 unsigned char *abuf = NULL;
867 int alen;
868 size_t siglen;
869 const EVP_MD *md = NULL;
870
871 md = EVP_get_digestbyobj(si->digest_alg->algorithm);
872 if (md == NULL)
873 return 0;
874
875 EVP_MD_CTX_init(&mctx);
876 if (EVP_DigestSignInit(&mctx, &pctx, md, NULL, si->pkey) <= 0)
877 goto err;
878
879 if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_SIGN,
880 EVP_PKEY_CTRL_PKCS7_SIGN, 0, si) <= 0) {
881 PKCS7error(PKCS7_R_CTRL_ERROR);
882 goto err;
883 }
884
885 alen = ASN1_item_i2d((ASN1_VALUE *)si->auth_attr, &abuf,
886 &PKCS7_ATTR_SIGN_it);
887 if (!abuf)
888 goto err;
889 if (EVP_DigestSignUpdate(&mctx, abuf, alen) <= 0)
890 goto err;
891 free(abuf);
892 abuf = NULL;
893 if (EVP_DigestSignFinal(&mctx, NULL, &siglen) <= 0)
894 goto err;
895 abuf = malloc(siglen);
896 if (!abuf)
897 goto err;
898 if (EVP_DigestSignFinal(&mctx, abuf, &siglen) <= 0)
899 goto err;
900
901 if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_SIGN,
902 EVP_PKEY_CTRL_PKCS7_SIGN, 1, si) <= 0) {
903 PKCS7error(PKCS7_R_CTRL_ERROR);
904 goto err;
905 }
906
907 EVP_MD_CTX_cleanup(&mctx);
908
909 ASN1_STRING_set0(si->enc_digest, abuf, siglen);
910
911 return 1;
912
913 err:
914 free(abuf);
915 EVP_MD_CTX_cleanup(&mctx);
916 return 0;
917 }
918
919 int
PKCS7_dataVerify(X509_STORE * cert_store,X509_STORE_CTX * ctx,BIO * bio,PKCS7 * p7,PKCS7_SIGNER_INFO * si)920 PKCS7_dataVerify(X509_STORE *cert_store, X509_STORE_CTX *ctx, BIO *bio,
921 PKCS7 *p7, PKCS7_SIGNER_INFO *si)
922 {
923 PKCS7_ISSUER_AND_SERIAL *ias;
924 int ret = 0, i;
925 STACK_OF(X509) *cert;
926 X509 *x509;
927
928 if (p7 == NULL) {
929 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
930 return 0;
931 }
932
933 if (p7->d.ptr == NULL) {
934 PKCS7error(PKCS7_R_NO_CONTENT);
935 return 0;
936 }
937
938 if (PKCS7_type_is_signed(p7)) {
939 cert = p7->d.sign->cert;
940 } else if (PKCS7_type_is_signedAndEnveloped(p7)) {
941 cert = p7->d.signed_and_enveloped->cert;
942 } else {
943 PKCS7error(PKCS7_R_WRONG_PKCS7_TYPE);
944 goto err;
945 }
946 /* XXXX */
947 ias = si->issuer_and_serial;
948
949 x509 = X509_find_by_issuer_and_serial(cert, ias->issuer, ias->serial);
950
951 /* were we able to find the cert in passed to us */
952 if (x509 == NULL) {
953 PKCS7error(PKCS7_R_UNABLE_TO_FIND_CERTIFICATE);
954 goto err;
955 }
956
957 /* Lets verify */
958 if (!X509_STORE_CTX_init(ctx, cert_store, x509, cert)) {
959 PKCS7error(ERR_R_X509_LIB);
960 goto err;
961 }
962 if (X509_STORE_CTX_set_purpose(ctx, X509_PURPOSE_SMIME_SIGN) == 0) {
963 X509_STORE_CTX_cleanup(ctx);
964 goto err;
965 }
966 i = X509_verify_cert(ctx);
967 if (i <= 0) {
968 PKCS7error(ERR_R_X509_LIB);
969 X509_STORE_CTX_cleanup(ctx);
970 goto err;
971 }
972 X509_STORE_CTX_cleanup(ctx);
973
974 return PKCS7_signatureVerify(bio, p7, si, x509);
975 err:
976
977 return ret;
978 }
979
980 int
PKCS7_signatureVerify(BIO * bio,PKCS7 * p7,PKCS7_SIGNER_INFO * si,X509 * x509)981 PKCS7_signatureVerify(BIO *bio, PKCS7 *p7, PKCS7_SIGNER_INFO *si, X509 *x509)
982 {
983 ASN1_OCTET_STRING *os;
984 EVP_MD_CTX mdc_tmp, *mdc;
985 int ret = 0, i;
986 int md_type;
987 STACK_OF(X509_ATTRIBUTE) *sk;
988 BIO *btmp;
989 EVP_PKEY *pkey;
990
991 EVP_MD_CTX_init(&mdc_tmp);
992
993 if (!PKCS7_type_is_signed(p7) &&
994 !PKCS7_type_is_signedAndEnveloped(p7)) {
995 PKCS7error(PKCS7_R_WRONG_PKCS7_TYPE);
996 goto err;
997 }
998
999 md_type = OBJ_obj2nid(si->digest_alg->algorithm);
1000
1001 btmp = bio;
1002 for (;;) {
1003 if ((btmp == NULL) ||
1004 ((btmp = BIO_find_type(btmp, BIO_TYPE_MD)) == NULL)) {
1005 PKCS7error(PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
1006 goto err;
1007 }
1008 BIO_get_md_ctx(btmp, &mdc);
1009 if (mdc == NULL) {
1010 PKCS7error(ERR_R_INTERNAL_ERROR);
1011 goto err;
1012 }
1013 if (EVP_MD_CTX_type(mdc) == md_type)
1014 break;
1015 /* Workaround for some broken clients that put the signature
1016 * OID instead of the digest OID in digest_alg->algorithm
1017 */
1018 if (EVP_MD_pkey_type(EVP_MD_CTX_md(mdc)) == md_type)
1019 break;
1020 btmp = BIO_next(btmp);
1021 }
1022
1023 /* mdc is the digest ctx that we want, unless there are attributes,
1024 * in which case the digest is the signed attributes */
1025 if (!EVP_MD_CTX_copy_ex(&mdc_tmp, mdc))
1026 goto err;
1027
1028 sk = si->auth_attr;
1029 if ((sk != NULL) && (sk_X509_ATTRIBUTE_num(sk) != 0)) {
1030 unsigned char md_dat[EVP_MAX_MD_SIZE], *abuf = NULL;
1031 unsigned int md_len;
1032 int alen;
1033 ASN1_OCTET_STRING *message_digest;
1034
1035 if (!EVP_DigestFinal_ex(&mdc_tmp, md_dat, &md_len))
1036 goto err;
1037 message_digest = PKCS7_digest_from_attributes(sk);
1038 if (!message_digest) {
1039 PKCS7error(PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
1040 goto err;
1041 }
1042 if ((message_digest->length != (int)md_len) ||
1043 (memcmp(message_digest->data, md_dat, md_len))) {
1044 PKCS7error(PKCS7_R_DIGEST_FAILURE);
1045 ret = -1;
1046 goto err;
1047 }
1048
1049 if (!EVP_VerifyInit_ex(&mdc_tmp, EVP_get_digestbynid(md_type),
1050 NULL))
1051 goto err;
1052
1053 alen = ASN1_item_i2d((ASN1_VALUE *)sk, &abuf,
1054 &PKCS7_ATTR_VERIFY_it);
1055 if (alen <= 0) {
1056 PKCS7error(ERR_R_ASN1_LIB);
1057 ret = -1;
1058 goto err;
1059 }
1060 if (!EVP_VerifyUpdate(&mdc_tmp, abuf, alen))
1061 goto err;
1062
1063 free(abuf);
1064 }
1065
1066 os = si->enc_digest;
1067 pkey = X509_get_pubkey(x509);
1068 if (!pkey) {
1069 ret = -1;
1070 goto err;
1071 }
1072
1073 i = EVP_VerifyFinal(&mdc_tmp, os->data, os->length, pkey);
1074 EVP_PKEY_free(pkey);
1075 if (i <= 0) {
1076 PKCS7error(PKCS7_R_SIGNATURE_FAILURE);
1077 ret = -1;
1078 goto err;
1079 } else
1080 ret = 1;
1081 err:
1082 EVP_MD_CTX_cleanup(&mdc_tmp);
1083 return (ret);
1084 }
1085
1086 PKCS7_ISSUER_AND_SERIAL *
PKCS7_get_issuer_and_serial(PKCS7 * p7,int idx)1087 PKCS7_get_issuer_and_serial(PKCS7 *p7, int idx)
1088 {
1089 STACK_OF(PKCS7_RECIP_INFO) *rsk;
1090 PKCS7_RECIP_INFO *ri;
1091 int i;
1092
1093 i = OBJ_obj2nid(p7->type);
1094 if (i != NID_pkcs7_signedAndEnveloped)
1095 return NULL;
1096 if (p7->d.signed_and_enveloped == NULL)
1097 return NULL;
1098 rsk = p7->d.signed_and_enveloped->recipientinfo;
1099 if (rsk == NULL)
1100 return NULL;
1101 ri = sk_PKCS7_RECIP_INFO_value(rsk, 0);
1102 if (sk_PKCS7_RECIP_INFO_num(rsk) <= idx)
1103 return (NULL);
1104 ri = sk_PKCS7_RECIP_INFO_value(rsk, idx);
1105 return (ri->issuer_and_serial);
1106 }
1107
1108 ASN1_TYPE *
PKCS7_get_signed_attribute(PKCS7_SIGNER_INFO * si,int nid)1109 PKCS7_get_signed_attribute(PKCS7_SIGNER_INFO *si, int nid)
1110 {
1111 return (get_attribute(si->auth_attr, nid));
1112 }
1113
1114 ASN1_TYPE *
PKCS7_get_attribute(PKCS7_SIGNER_INFO * si,int nid)1115 PKCS7_get_attribute(PKCS7_SIGNER_INFO *si, int nid)
1116 {
1117 return (get_attribute(si->unauth_attr, nid));
1118 }
1119
1120 static ASN1_TYPE *
get_attribute(STACK_OF (X509_ATTRIBUTE)* sk,int nid)1121 get_attribute(STACK_OF(X509_ATTRIBUTE) *sk, int nid)
1122 {
1123 int i;
1124 X509_ATTRIBUTE *xa;
1125 ASN1_OBJECT *o;
1126
1127 o = OBJ_nid2obj(nid);
1128 if (!o || !sk)
1129 return (NULL);
1130 for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
1131 xa = sk_X509_ATTRIBUTE_value(sk, i);
1132 if (OBJ_cmp(xa->object, o) == 0)
1133 return (sk_ASN1_TYPE_value(xa->set, 0));
1134 }
1135 return (NULL);
1136 }
1137
1138 ASN1_OCTET_STRING *
PKCS7_digest_from_attributes(STACK_OF (X509_ATTRIBUTE)* sk)1139 PKCS7_digest_from_attributes(STACK_OF(X509_ATTRIBUTE) *sk)
1140 {
1141 ASN1_TYPE *astype;
1142
1143 if (!(astype = get_attribute(sk, NID_pkcs9_messageDigest)))
1144 return NULL;
1145 if (astype->type != V_ASN1_OCTET_STRING)
1146 return NULL;
1147 return astype->value.octet_string;
1148 }
1149
1150 int
PKCS7_set_signed_attributes(PKCS7_SIGNER_INFO * p7si,STACK_OF (X509_ATTRIBUTE)* sk)1151 PKCS7_set_signed_attributes(PKCS7_SIGNER_INFO *p7si,
1152 STACK_OF(X509_ATTRIBUTE) *sk)
1153 {
1154 int i;
1155
1156 if (p7si->auth_attr != NULL)
1157 sk_X509_ATTRIBUTE_pop_free(p7si->auth_attr,
1158 X509_ATTRIBUTE_free);
1159 p7si->auth_attr = sk_X509_ATTRIBUTE_dup(sk);
1160 if (p7si->auth_attr == NULL)
1161 return 0;
1162 for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
1163 if ((sk_X509_ATTRIBUTE_set(p7si->auth_attr, i,
1164 X509_ATTRIBUTE_dup(sk_X509_ATTRIBUTE_value(sk, i))))
1165 == NULL)
1166 return (0);
1167 }
1168 return (1);
1169 }
1170
1171 int
PKCS7_set_attributes(PKCS7_SIGNER_INFO * p7si,STACK_OF (X509_ATTRIBUTE)* sk)1172 PKCS7_set_attributes(PKCS7_SIGNER_INFO *p7si, STACK_OF(X509_ATTRIBUTE) *sk)
1173 {
1174 int i;
1175
1176 if (p7si->unauth_attr != NULL)
1177 sk_X509_ATTRIBUTE_pop_free(p7si->unauth_attr,
1178 X509_ATTRIBUTE_free);
1179 p7si->unauth_attr = sk_X509_ATTRIBUTE_dup(sk);
1180 if (p7si->unauth_attr == NULL)
1181 return 0;
1182 for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
1183 if ((sk_X509_ATTRIBUTE_set(p7si->unauth_attr, i,
1184 X509_ATTRIBUTE_dup(sk_X509_ATTRIBUTE_value(sk, i))))
1185 == NULL)
1186 return (0);
1187 }
1188 return (1);
1189 }
1190
1191 int
PKCS7_add_signed_attribute(PKCS7_SIGNER_INFO * p7si,int nid,int atrtype,void * value)1192 PKCS7_add_signed_attribute(PKCS7_SIGNER_INFO *p7si, int nid, int atrtype,
1193 void *value)
1194 {
1195 return (add_attribute(&(p7si->auth_attr), nid, atrtype, value));
1196 }
1197
1198 int
PKCS7_add_attribute(PKCS7_SIGNER_INFO * p7si,int nid,int atrtype,void * value)1199 PKCS7_add_attribute(PKCS7_SIGNER_INFO *p7si, int nid, int atrtype, void *value)
1200 {
1201 return (add_attribute(&(p7si->unauth_attr), nid, atrtype, value));
1202 }
1203
1204 static int
add_attribute(STACK_OF (X509_ATTRIBUTE)** sk,int nid,int atrtype,void * value)1205 add_attribute(STACK_OF(X509_ATTRIBUTE) **sk, int nid, int atrtype, void *value)
1206 {
1207 X509_ATTRIBUTE *attr = NULL;
1208
1209 if (*sk == NULL) {
1210 *sk = sk_X509_ATTRIBUTE_new_null();
1211 if (*sk == NULL)
1212 return 0;
1213 new_attrib:
1214 if (!(attr = X509_ATTRIBUTE_create(nid, atrtype, value)))
1215 return 0;
1216 if (!sk_X509_ATTRIBUTE_push(*sk, attr)) {
1217 X509_ATTRIBUTE_free(attr);
1218 return 0;
1219 }
1220 } else {
1221 int i;
1222
1223 for (i = 0; i < sk_X509_ATTRIBUTE_num(*sk); i++) {
1224 attr = sk_X509_ATTRIBUTE_value(*sk, i);
1225 if (OBJ_obj2nid(attr->object) == nid) {
1226 X509_ATTRIBUTE_free(attr);
1227 attr = X509_ATTRIBUTE_create(nid, atrtype,
1228 value);
1229 if (attr == NULL)
1230 return 0;
1231 if (!sk_X509_ATTRIBUTE_set(*sk, i, attr)) {
1232 X509_ATTRIBUTE_free(attr);
1233 return 0;
1234 }
1235 goto end;
1236 }
1237 }
1238 goto new_attrib;
1239 }
1240 end:
1241 return (1);
1242 }
1243