1 /* $OpenBSD: pk7_smime.c,v 1.23 2021/11/01 20:53:08 tb Exp $ */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3 * project.
4 */
5 /* ====================================================================
6 * Copyright (c) 1999-2004 The OpenSSL Project. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * 3. All advertising materials mentioning features or use of this
21 * software must display the following acknowledgment:
22 * "This product includes software developed by the OpenSSL Project
23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24 *
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 * endorse or promote products derived from this software without
27 * prior written permission. For written permission, please contact
28 * licensing@OpenSSL.org.
29 *
30 * 5. Products derived from this software may not be called "OpenSSL"
31 * nor may "OpenSSL" appear in their names without prior written
32 * permission of the OpenSSL Project.
33 *
34 * 6. Redistributions of any form whatsoever must retain the following
35 * acknowledgment:
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38 *
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
52 *
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com). This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
56 *
57 */
58
59 /* Simple PKCS#7 processing functions */
60
61 #include <stdio.h>
62
63 #include <openssl/err.h>
64 #include <openssl/x509.h>
65 #include <openssl/x509v3.h>
66
67 #include "x509_lcl.h"
68
69 static int pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si);
70
71 PKCS7 *
PKCS7_sign(X509 * signcert,EVP_PKEY * pkey,STACK_OF (X509)* certs,BIO * data,int flags)72 PKCS7_sign(X509 *signcert, EVP_PKEY *pkey, STACK_OF(X509) *certs, BIO *data,
73 int flags)
74 {
75 PKCS7 *p7;
76 int i;
77
78 if (!(p7 = PKCS7_new())) {
79 PKCS7error(ERR_R_MALLOC_FAILURE);
80 return NULL;
81 }
82
83 if (!PKCS7_set_type(p7, NID_pkcs7_signed))
84 goto err;
85
86 if (!PKCS7_content_new(p7, NID_pkcs7_data))
87 goto err;
88
89 if (pkey && !PKCS7_sign_add_signer(p7, signcert, pkey, NULL, flags)) {
90 PKCS7error(PKCS7_R_PKCS7_ADD_SIGNER_ERROR);
91 goto err;
92 }
93
94 if (!(flags & PKCS7_NOCERTS)) {
95 for (i = 0; i < sk_X509_num(certs); i++) {
96 if (!PKCS7_add_certificate(p7, sk_X509_value(certs, i)))
97 goto err;
98 }
99 }
100
101 if (flags & PKCS7_DETACHED)
102 PKCS7_set_detached(p7, 1);
103
104 if (flags & (PKCS7_STREAM|PKCS7_PARTIAL))
105 return p7;
106
107 if (PKCS7_final(p7, data, flags))
108 return p7;
109
110 err:
111 PKCS7_free(p7);
112 return NULL;
113 }
114
115 int
PKCS7_final(PKCS7 * p7,BIO * data,int flags)116 PKCS7_final(PKCS7 *p7, BIO *data, int flags)
117 {
118 BIO *p7bio;
119 int ret = 0;
120
121 if (!(p7bio = PKCS7_dataInit(p7, NULL))) {
122 PKCS7error(ERR_R_MALLOC_FAILURE);
123 return 0;
124 }
125
126 SMIME_crlf_copy(data, p7bio, flags);
127
128 (void)BIO_flush(p7bio);
129
130 if (!PKCS7_dataFinal(p7, p7bio)) {
131 PKCS7error(PKCS7_R_PKCS7_DATASIGN);
132 goto err;
133 }
134
135 ret = 1;
136
137 err:
138 BIO_free_all(p7bio);
139
140 return ret;
141 }
142
143 /* Check to see if a cipher exists and if so add S/MIME capabilities */
144
145 static int
add_cipher_smcap(STACK_OF (X509_ALGOR)* sk,int nid,int arg)146 add_cipher_smcap(STACK_OF(X509_ALGOR) *sk, int nid, int arg)
147 {
148 if (EVP_get_cipherbynid(nid))
149 return PKCS7_simple_smimecap(sk, nid, arg);
150 return 1;
151 }
152
153 static int
add_digest_smcap(STACK_OF (X509_ALGOR)* sk,int nid,int arg)154 add_digest_smcap(STACK_OF(X509_ALGOR) *sk, int nid, int arg)
155 {
156 if (EVP_get_digestbynid(nid))
157 return PKCS7_simple_smimecap(sk, nid, arg);
158 return 1;
159 }
160
161 PKCS7_SIGNER_INFO *
PKCS7_sign_add_signer(PKCS7 * p7,X509 * signcert,EVP_PKEY * pkey,const EVP_MD * md,int flags)162 PKCS7_sign_add_signer(PKCS7 *p7, X509 *signcert, EVP_PKEY *pkey,
163 const EVP_MD *md, int flags)
164 {
165 PKCS7_SIGNER_INFO *si = NULL;
166 STACK_OF(X509_ALGOR) *smcap = NULL;
167
168 if (!X509_check_private_key(signcert, pkey)) {
169 PKCS7error(PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
170 return NULL;
171 }
172
173 if (!(si = PKCS7_add_signature(p7, signcert, pkey, md))) {
174 PKCS7error(PKCS7_R_PKCS7_ADD_SIGNATURE_ERROR);
175 return NULL;
176 }
177
178 if (!(flags & PKCS7_NOCERTS)) {
179 if (!PKCS7_add_certificate(p7, signcert))
180 goto err;
181 }
182
183 if (!(flags & PKCS7_NOATTR)) {
184 if (!PKCS7_add_attrib_content_type(si, NULL))
185 goto err;
186 /* Add SMIMECapabilities */
187 if (!(flags & PKCS7_NOSMIMECAP)) {
188 if (!(smcap = sk_X509_ALGOR_new_null())) {
189 PKCS7error(ERR_R_MALLOC_FAILURE);
190 goto err;
191 }
192 if (!add_cipher_smcap(smcap, NID_aes_256_cbc, -1) ||
193 !add_digest_smcap(smcap, NID_id_GostR3411_94, -1) ||
194 !add_digest_smcap(smcap, NID_id_tc26_gost3411_2012_256, -1) ||
195 !add_digest_smcap(smcap, NID_id_tc26_gost3411_2012_512, -1) ||
196 !add_cipher_smcap(smcap, NID_id_Gost28147_89, -1) ||
197 !add_cipher_smcap(smcap, NID_aes_192_cbc, -1) ||
198 !add_cipher_smcap(smcap, NID_aes_128_cbc, -1) ||
199 !add_cipher_smcap(smcap, NID_des_ede3_cbc, -1) ||
200 !add_cipher_smcap(smcap, NID_rc2_cbc, 128) ||
201 !add_cipher_smcap(smcap, NID_rc2_cbc, 64) ||
202 !add_cipher_smcap(smcap, NID_des_cbc, -1) ||
203 !add_cipher_smcap(smcap, NID_rc2_cbc, 40) ||
204 !PKCS7_add_attrib_smimecap(si, smcap))
205 goto err;
206 sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free);
207 smcap = NULL;
208 }
209 if (flags & PKCS7_REUSE_DIGEST) {
210 if (!pkcs7_copy_existing_digest(p7, si))
211 goto err;
212 if (!(flags & PKCS7_PARTIAL) &&
213 !PKCS7_SIGNER_INFO_sign(si))
214 goto err;
215 }
216 }
217 return si;
218
219 err:
220 if (smcap)
221 sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free);
222 return NULL;
223 }
224
225 /* Search for a digest matching SignerInfo digest type and if found
226 * copy across.
227 */
228
229 static int
pkcs7_copy_existing_digest(PKCS7 * p7,PKCS7_SIGNER_INFO * si)230 pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si)
231 {
232 int i;
233 STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
234 PKCS7_SIGNER_INFO *sitmp;
235 ASN1_OCTET_STRING *osdig = NULL;
236
237 sinfos = PKCS7_get_signer_info(p7);
238 for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
239 sitmp = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
240 if (si == sitmp)
241 break;
242 if (sk_X509_ATTRIBUTE_num(sitmp->auth_attr) <= 0)
243 continue;
244 if (!OBJ_cmp(si->digest_alg->algorithm,
245 sitmp->digest_alg->algorithm)) {
246 osdig = PKCS7_digest_from_attributes(sitmp->auth_attr);
247 break;
248 }
249
250 }
251
252 if (osdig)
253 return PKCS7_add1_attrib_digest(si, osdig->data, osdig->length);
254
255 PKCS7error(PKCS7_R_NO_MATCHING_DIGEST_TYPE_FOUND);
256 return 0;
257 }
258
259 int
PKCS7_verify(PKCS7 * p7,STACK_OF (X509)* certs,X509_STORE * store,BIO * indata,BIO * out,int flags)260 PKCS7_verify(PKCS7 *p7, STACK_OF(X509) *certs, X509_STORE *store, BIO *indata,
261 BIO *out, int flags)
262 {
263 STACK_OF(X509) *signers;
264 X509 *signer;
265 STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
266 PKCS7_SIGNER_INFO *si;
267 X509_STORE_CTX cert_ctx;
268 char buf[4096];
269 int i, j = 0, k, ret = 0;
270 BIO *p7bio;
271 BIO *tmpin, *tmpout;
272
273 if (!p7) {
274 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
275 return 0;
276 }
277
278 if (!PKCS7_type_is_signed(p7)) {
279 PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE);
280 return 0;
281 }
282
283 /* Check for no data and no content: no data to verify signature */
284 if (PKCS7_get_detached(p7) && !indata) {
285 PKCS7error(PKCS7_R_NO_CONTENT);
286 return 0;
287 }
288
289 /*
290 * Very old Netscape illegally included empty content with
291 * a detached signature. Very old users should upgrade.
292 */
293 /* Check for data and content: two sets of data */
294 if (!PKCS7_get_detached(p7) && indata) {
295 PKCS7error(PKCS7_R_CONTENT_AND_DATA_PRESENT);
296 return 0;
297 }
298
299 sinfos = PKCS7_get_signer_info(p7);
300
301 if (!sinfos || !sk_PKCS7_SIGNER_INFO_num(sinfos)) {
302 PKCS7error(PKCS7_R_NO_SIGNATURES_ON_DATA);
303 return 0;
304 }
305
306
307 signers = PKCS7_get0_signers(p7, certs, flags);
308
309 if (!signers)
310 return 0;
311
312 /* Now verify the certificates */
313
314 if (!(flags & PKCS7_NOVERIFY))
315 for (k = 0; k < sk_X509_num(signers); k++) {
316 signer = sk_X509_value (signers, k);
317 if (!(flags & PKCS7_NOCHAIN)) {
318 if (!X509_STORE_CTX_init(&cert_ctx, store,
319 signer, p7->d.sign->cert)) {
320 PKCS7error(ERR_R_X509_LIB);
321 sk_X509_free(signers);
322 return 0;
323 }
324 if (X509_STORE_CTX_set_default(&cert_ctx,
325 "smime_sign") == 0) {
326 sk_X509_free(signers);
327 return 0;
328 }
329 } else if (!X509_STORE_CTX_init(&cert_ctx, store,
330 signer, NULL)) {
331 PKCS7error(ERR_R_X509_LIB);
332 sk_X509_free(signers);
333 return 0;
334 }
335 if (!(flags & PKCS7_NOCRL))
336 X509_STORE_CTX_set0_crls(&cert_ctx, p7->d.sign->crl);
337 i = X509_verify_cert(&cert_ctx);
338 if (i <= 0)
339 j = X509_STORE_CTX_get_error(&cert_ctx);
340 X509_STORE_CTX_cleanup(&cert_ctx);
341 if (i <= 0) {
342 PKCS7error(PKCS7_R_CERTIFICATE_VERIFY_ERROR);
343 ERR_asprintf_error_data("Verify error:%s",
344 X509_verify_cert_error_string(j));
345 sk_X509_free(signers);
346 return 0;
347 }
348 /* Check for revocation status here */
349 }
350
351 /*
352 * Performance optimization: if the content is a memory BIO then
353 * store its contents in a temporary read only memory BIO. This
354 * avoids potentially large numbers of slow copies of data which will
355 * occur when reading from a read write memory BIO when signatures
356 * are calculated.
357 */
358 if (indata && (BIO_method_type(indata) == BIO_TYPE_MEM)) {
359 char *ptr;
360 long len;
361
362 len = BIO_get_mem_data(indata, &ptr);
363 tmpin = BIO_new_mem_buf(ptr, len);
364 if (tmpin == NULL) {
365 PKCS7error(ERR_R_MALLOC_FAILURE);
366 return 0;
367 }
368 } else
369 tmpin = indata;
370
371
372 if (!(p7bio = PKCS7_dataInit(p7, tmpin)))
373 goto err;
374
375 if (flags & PKCS7_TEXT) {
376 if (!(tmpout = BIO_new(BIO_s_mem()))) {
377 PKCS7error(ERR_R_MALLOC_FAILURE);
378 goto err;
379 }
380 BIO_set_mem_eof_return(tmpout, 0);
381 } else
382 tmpout = out;
383
384 /* We now have to 'read' from p7bio to calculate digests etc. */
385 for (;;) {
386 i = BIO_read(p7bio, buf, sizeof(buf));
387 if (i <= 0)
388 break;
389 if (tmpout)
390 BIO_write(tmpout, buf, i);
391 }
392
393 if (flags & PKCS7_TEXT) {
394 if (!SMIME_text(tmpout, out)) {
395 PKCS7error(PKCS7_R_SMIME_TEXT_ERROR);
396 BIO_free(tmpout);
397 goto err;
398 }
399 BIO_free(tmpout);
400 }
401
402 /* Now Verify All Signatures */
403 if (!(flags & PKCS7_NOSIGS))
404 for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
405 si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
406 signer = sk_X509_value (signers, i);
407 j = PKCS7_signatureVerify(p7bio, p7, si, signer);
408 if (j <= 0) {
409 PKCS7error(PKCS7_R_SIGNATURE_FAILURE);
410 goto err;
411 }
412 }
413
414 ret = 1;
415
416 err:
417 if (tmpin == indata) {
418 if (indata)
419 BIO_pop(p7bio);
420 }
421 BIO_free_all(p7bio);
422 sk_X509_free(signers);
423
424 return ret;
425 }
426
STACK_OF(X509)427 STACK_OF(X509) *
428 PKCS7_get0_signers(PKCS7 *p7, STACK_OF(X509) *certs, int flags)
429 {
430 STACK_OF(X509) *signers;
431 STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
432 PKCS7_SIGNER_INFO *si;
433 PKCS7_ISSUER_AND_SERIAL *ias;
434 X509 *signer;
435 int i;
436
437 if (!p7) {
438 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
439 return NULL;
440 }
441
442 if (!PKCS7_type_is_signed(p7)) {
443 PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE);
444 return NULL;
445 }
446
447 /* Collect all the signers together */
448 sinfos = PKCS7_get_signer_info(p7);
449 if (sk_PKCS7_SIGNER_INFO_num(sinfos) <= 0) {
450 PKCS7error(PKCS7_R_NO_SIGNERS);
451 return 0;
452 }
453
454 if (!(signers = sk_X509_new_null())) {
455 PKCS7error(ERR_R_MALLOC_FAILURE);
456 return NULL;
457 }
458
459 for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
460 si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
461 ias = si->issuer_and_serial;
462 signer = NULL;
463 /* If any certificates passed they take priority */
464 if (certs)
465 signer = X509_find_by_issuer_and_serial (certs,
466 ias->issuer, ias->serial);
467 if (!signer && !(flags & PKCS7_NOINTERN) && p7->d.sign->cert)
468 signer =
469 X509_find_by_issuer_and_serial(p7->d.sign->cert,
470 ias->issuer, ias->serial);
471 if (!signer) {
472 PKCS7error(PKCS7_R_SIGNER_CERTIFICATE_NOT_FOUND);
473 sk_X509_free(signers);
474 return 0;
475 }
476
477 if (!sk_X509_push(signers, signer)) {
478 sk_X509_free(signers);
479 return NULL;
480 }
481 }
482 return signers;
483 }
484
485 /* Build a complete PKCS#7 enveloped data */
486
487 PKCS7 *
PKCS7_encrypt(STACK_OF (X509)* certs,BIO * in,const EVP_CIPHER * cipher,int flags)488 PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher,
489 int flags)
490 {
491 PKCS7 *p7;
492 BIO *p7bio = NULL;
493 int i;
494 X509 *x509;
495
496 if (!(p7 = PKCS7_new())) {
497 PKCS7error(ERR_R_MALLOC_FAILURE);
498 return NULL;
499 }
500
501 if (!PKCS7_set_type(p7, NID_pkcs7_enveloped))
502 goto err;
503 if (!PKCS7_set_cipher(p7, cipher)) {
504 PKCS7error(PKCS7_R_ERROR_SETTING_CIPHER);
505 goto err;
506 }
507
508 for (i = 0; i < sk_X509_num(certs); i++) {
509 x509 = sk_X509_value(certs, i);
510 if (!PKCS7_add_recipient(p7, x509)) {
511 PKCS7error(PKCS7_R_ERROR_ADDING_RECIPIENT);
512 goto err;
513 }
514 }
515
516 if (flags & PKCS7_STREAM)
517 return p7;
518
519 if (PKCS7_final(p7, in, flags))
520 return p7;
521
522 err:
523 BIO_free_all(p7bio);
524 PKCS7_free(p7);
525 return NULL;
526 }
527
528 int
PKCS7_decrypt(PKCS7 * p7,EVP_PKEY * pkey,X509 * cert,BIO * data,int flags)529 PKCS7_decrypt(PKCS7 *p7, EVP_PKEY *pkey, X509 *cert, BIO *data, int flags)
530 {
531 BIO *tmpmem;
532 int ret, i;
533 char buf[4096];
534
535 if (!p7) {
536 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
537 return 0;
538 }
539
540 if (!PKCS7_type_is_enveloped(p7)) {
541 PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE);
542 return 0;
543 }
544
545 if (cert && !X509_check_private_key(cert, pkey)) {
546 PKCS7error(PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
547 return 0;
548 }
549
550 if (!(tmpmem = PKCS7_dataDecode(p7, pkey, NULL, cert))) {
551 PKCS7error(PKCS7_R_DECRYPT_ERROR);
552 return 0;
553 }
554
555 if (flags & PKCS7_TEXT) {
556 BIO *tmpbuf;
557
558 /* Encrypt BIOs can't do BIO_gets() so add a buffer BIO */
559 if (!(tmpbuf = BIO_new(BIO_f_buffer()))) {
560 PKCS7error(ERR_R_MALLOC_FAILURE);
561 BIO_free_all(tmpmem);
562 return 0;
563 }
564 BIO_push(tmpbuf, tmpmem);
565 ret = SMIME_text(tmpbuf, data);
566 if (ret > 0 && BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) {
567 if (!BIO_get_cipher_status(tmpmem))
568 ret = 0;
569 }
570 BIO_free_all(tmpbuf);
571 return ret;
572 } else {
573 for (;;) {
574 i = BIO_read(tmpmem, buf, sizeof(buf));
575 if (i <= 0) {
576 ret = 1;
577 if (BIO_method_type(tmpmem) ==
578 BIO_TYPE_CIPHER) {
579 if (!BIO_get_cipher_status(tmpmem))
580 ret = 0;
581 }
582 break;
583 }
584 if (BIO_write(data, buf, i) != i) {
585 ret = 0;
586 break;
587 }
588 }
589 BIO_free_all(tmpmem);
590 return ret;
591 }
592 }
593