1 /* $OpenBSD: pk7_smime.c,v 1.27 2024/04/20 10:11:55 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_local.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 LCRYPTO_ALIAS(PKCS7_sign);
115
116 int
PKCS7_final(PKCS7 * p7,BIO * data,int flags)117 PKCS7_final(PKCS7 *p7, BIO *data, int flags)
118 {
119 BIO *p7bio;
120 int ret = 0;
121
122 if (!(p7bio = PKCS7_dataInit(p7, NULL))) {
123 PKCS7error(ERR_R_MALLOC_FAILURE);
124 return 0;
125 }
126
127 SMIME_crlf_copy(data, p7bio, flags);
128
129 (void)BIO_flush(p7bio);
130
131 if (!PKCS7_dataFinal(p7, p7bio)) {
132 PKCS7error(PKCS7_R_PKCS7_DATASIGN);
133 goto err;
134 }
135
136 ret = 1;
137
138 err:
139 BIO_free_all(p7bio);
140
141 return ret;
142 }
143 LCRYPTO_ALIAS(PKCS7_final);
144
145 /* Check to see if a cipher exists and if so add S/MIME capabilities */
146
147 static int
add_cipher_smcap(STACK_OF (X509_ALGOR)* sk,int nid,int arg)148 add_cipher_smcap(STACK_OF(X509_ALGOR) *sk, int nid, int arg)
149 {
150 if (EVP_get_cipherbynid(nid))
151 return PKCS7_simple_smimecap(sk, nid, arg);
152 return 1;
153 }
154
155 PKCS7_SIGNER_INFO *
PKCS7_sign_add_signer(PKCS7 * p7,X509 * signcert,EVP_PKEY * pkey,const EVP_MD * md,int flags)156 PKCS7_sign_add_signer(PKCS7 *p7, X509 *signcert, EVP_PKEY *pkey,
157 const EVP_MD *md, int flags)
158 {
159 PKCS7_SIGNER_INFO *si = NULL;
160 STACK_OF(X509_ALGOR) *smcap = NULL;
161
162 if (!X509_check_private_key(signcert, pkey)) {
163 PKCS7error(PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
164 return NULL;
165 }
166
167 if (!(si = PKCS7_add_signature(p7, signcert, pkey, md))) {
168 PKCS7error(PKCS7_R_PKCS7_ADD_SIGNATURE_ERROR);
169 return NULL;
170 }
171
172 if (!(flags & PKCS7_NOCERTS)) {
173 if (!PKCS7_add_certificate(p7, signcert))
174 goto err;
175 }
176
177 if (!(flags & PKCS7_NOATTR)) {
178 if (!PKCS7_add_attrib_content_type(si, NULL))
179 goto err;
180 /* Add SMIMECapabilities */
181 if (!(flags & PKCS7_NOSMIMECAP)) {
182 if (!(smcap = sk_X509_ALGOR_new_null())) {
183 PKCS7error(ERR_R_MALLOC_FAILURE);
184 goto err;
185 }
186 if (!add_cipher_smcap(smcap, NID_aes_256_cbc, -1) ||
187 !add_cipher_smcap(smcap, NID_aes_192_cbc, -1) ||
188 !add_cipher_smcap(smcap, NID_aes_128_cbc, -1) ||
189 !add_cipher_smcap(smcap, NID_des_ede3_cbc, -1) ||
190 !add_cipher_smcap(smcap, NID_rc2_cbc, 128) ||
191 !add_cipher_smcap(smcap, NID_rc2_cbc, 64) ||
192 !add_cipher_smcap(smcap, NID_des_cbc, -1) ||
193 !add_cipher_smcap(smcap, NID_rc2_cbc, 40) ||
194 !PKCS7_add_attrib_smimecap(si, smcap))
195 goto err;
196 sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free);
197 smcap = NULL;
198 }
199 if (flags & PKCS7_REUSE_DIGEST) {
200 if (!pkcs7_copy_existing_digest(p7, si))
201 goto err;
202 if (!(flags & PKCS7_PARTIAL) &&
203 !PKCS7_SIGNER_INFO_sign(si))
204 goto err;
205 }
206 }
207 return si;
208
209 err:
210 if (smcap)
211 sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free);
212 return NULL;
213 }
214 LCRYPTO_ALIAS(PKCS7_sign_add_signer);
215
216 /* Search for a digest matching SignerInfo digest type and if found
217 * copy across.
218 */
219
220 static int
pkcs7_copy_existing_digest(PKCS7 * p7,PKCS7_SIGNER_INFO * si)221 pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si)
222 {
223 int i;
224 STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
225 PKCS7_SIGNER_INFO *sitmp;
226 ASN1_OCTET_STRING *osdig = NULL;
227
228 sinfos = PKCS7_get_signer_info(p7);
229 for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
230 sitmp = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
231 if (si == sitmp)
232 break;
233 if (sk_X509_ATTRIBUTE_num(sitmp->auth_attr) <= 0)
234 continue;
235 if (!OBJ_cmp(si->digest_alg->algorithm,
236 sitmp->digest_alg->algorithm)) {
237 osdig = PKCS7_digest_from_attributes(sitmp->auth_attr);
238 break;
239 }
240
241 }
242
243 if (osdig)
244 return PKCS7_add1_attrib_digest(si, osdig->data, osdig->length);
245
246 PKCS7error(PKCS7_R_NO_MATCHING_DIGEST_TYPE_FOUND);
247 return 0;
248 }
249
250 int
PKCS7_verify(PKCS7 * p7,STACK_OF (X509)* certs,X509_STORE * store,BIO * indata,BIO * out,int flags)251 PKCS7_verify(PKCS7 *p7, STACK_OF(X509) *certs, X509_STORE *store, BIO *indata,
252 BIO *out, int flags)
253 {
254 STACK_OF(X509) *signers;
255 X509 *signer;
256 STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
257 PKCS7_SIGNER_INFO *si;
258 X509_STORE_CTX cert_ctx;
259 char buf[4096];
260 int i, j = 0, k, ret = 0;
261 BIO *p7bio;
262 BIO *tmpin, *tmpout;
263
264 if (!p7) {
265 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
266 return 0;
267 }
268
269 if (!PKCS7_type_is_signed(p7)) {
270 PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE);
271 return 0;
272 }
273
274 /* Check for no data and no content: no data to verify signature */
275 if (PKCS7_get_detached(p7) && !indata) {
276 PKCS7error(PKCS7_R_NO_CONTENT);
277 return 0;
278 }
279
280 /*
281 * Very old Netscape illegally included empty content with
282 * a detached signature. Very old users should upgrade.
283 */
284 /* Check for data and content: two sets of data */
285 if (!PKCS7_get_detached(p7) && indata) {
286 PKCS7error(PKCS7_R_CONTENT_AND_DATA_PRESENT);
287 return 0;
288 }
289
290 sinfos = PKCS7_get_signer_info(p7);
291
292 if (!sinfos || !sk_PKCS7_SIGNER_INFO_num(sinfos)) {
293 PKCS7error(PKCS7_R_NO_SIGNATURES_ON_DATA);
294 return 0;
295 }
296
297
298 signers = PKCS7_get0_signers(p7, certs, flags);
299
300 if (!signers)
301 return 0;
302
303 /* Now verify the certificates */
304
305 if (!(flags & PKCS7_NOVERIFY))
306 for (k = 0; k < sk_X509_num(signers); k++) {
307 signer = sk_X509_value (signers, k);
308 if (!(flags & PKCS7_NOCHAIN)) {
309 if (!X509_STORE_CTX_init(&cert_ctx, store,
310 signer, p7->d.sign->cert)) {
311 PKCS7error(ERR_R_X509_LIB);
312 sk_X509_free(signers);
313 return 0;
314 }
315 if (X509_STORE_CTX_set_default(&cert_ctx,
316 "smime_sign") == 0) {
317 sk_X509_free(signers);
318 return 0;
319 }
320 } else if (!X509_STORE_CTX_init(&cert_ctx, store,
321 signer, NULL)) {
322 PKCS7error(ERR_R_X509_LIB);
323 sk_X509_free(signers);
324 return 0;
325 }
326 if (!(flags & PKCS7_NOCRL))
327 X509_STORE_CTX_set0_crls(&cert_ctx, p7->d.sign->crl);
328 i = X509_verify_cert(&cert_ctx);
329 if (i <= 0)
330 j = X509_STORE_CTX_get_error(&cert_ctx);
331 X509_STORE_CTX_cleanup(&cert_ctx);
332 if (i <= 0) {
333 PKCS7error(PKCS7_R_CERTIFICATE_VERIFY_ERROR);
334 ERR_asprintf_error_data("Verify error:%s",
335 X509_verify_cert_error_string(j));
336 sk_X509_free(signers);
337 return 0;
338 }
339 /* Check for revocation status here */
340 }
341
342 /*
343 * Performance optimization: if the content is a memory BIO then
344 * store its contents in a temporary read only memory BIO. This
345 * avoids potentially large numbers of slow copies of data which will
346 * occur when reading from a read write memory BIO when signatures
347 * are calculated.
348 */
349 if (indata && (BIO_method_type(indata) == BIO_TYPE_MEM)) {
350 char *ptr;
351 long len;
352
353 len = BIO_get_mem_data(indata, &ptr);
354 tmpin = BIO_new_mem_buf(ptr, len);
355 if (tmpin == NULL) {
356 PKCS7error(ERR_R_MALLOC_FAILURE);
357 return 0;
358 }
359 } else
360 tmpin = indata;
361
362
363 if (!(p7bio = PKCS7_dataInit(p7, tmpin)))
364 goto err;
365
366 if (flags & PKCS7_TEXT) {
367 if (!(tmpout = BIO_new(BIO_s_mem()))) {
368 PKCS7error(ERR_R_MALLOC_FAILURE);
369 goto err;
370 }
371 BIO_set_mem_eof_return(tmpout, 0);
372 } else
373 tmpout = out;
374
375 /* We now have to 'read' from p7bio to calculate digests etc. */
376 for (;;) {
377 i = BIO_read(p7bio, buf, sizeof(buf));
378 if (i <= 0)
379 break;
380 if (tmpout)
381 BIO_write(tmpout, buf, i);
382 }
383
384 if (flags & PKCS7_TEXT) {
385 if (!SMIME_text(tmpout, out)) {
386 PKCS7error(PKCS7_R_SMIME_TEXT_ERROR);
387 BIO_free(tmpout);
388 goto err;
389 }
390 BIO_free(tmpout);
391 }
392
393 /* Now Verify All Signatures */
394 if (!(flags & PKCS7_NOSIGS))
395 for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
396 si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
397 signer = sk_X509_value (signers, i);
398 j = PKCS7_signatureVerify(p7bio, p7, si, signer);
399 if (j <= 0) {
400 PKCS7error(PKCS7_R_SIGNATURE_FAILURE);
401 goto err;
402 }
403 }
404
405 ret = 1;
406
407 err:
408 if (tmpin == indata) {
409 if (indata)
410 BIO_pop(p7bio);
411 }
412 BIO_free_all(p7bio);
413 sk_X509_free(signers);
414
415 return ret;
416 }
417 LCRYPTO_ALIAS(PKCS7_verify);
418
STACK_OF(X509)419 STACK_OF(X509) *
420 PKCS7_get0_signers(PKCS7 *p7, STACK_OF(X509) *certs, int flags)
421 {
422 STACK_OF(X509) *signers;
423 STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
424 PKCS7_SIGNER_INFO *si;
425 PKCS7_ISSUER_AND_SERIAL *ias;
426 X509 *signer;
427 int i;
428
429 if (!p7) {
430 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
431 return NULL;
432 }
433
434 if (!PKCS7_type_is_signed(p7)) {
435 PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE);
436 return NULL;
437 }
438
439 /* Collect all the signers together */
440 sinfos = PKCS7_get_signer_info(p7);
441 if (sk_PKCS7_SIGNER_INFO_num(sinfos) <= 0) {
442 PKCS7error(PKCS7_R_NO_SIGNERS);
443 return 0;
444 }
445
446 if (!(signers = sk_X509_new_null())) {
447 PKCS7error(ERR_R_MALLOC_FAILURE);
448 return NULL;
449 }
450
451 for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
452 si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
453 ias = si->issuer_and_serial;
454 signer = NULL;
455 /* If any certificates passed they take priority */
456 if (certs)
457 signer = X509_find_by_issuer_and_serial (certs,
458 ias->issuer, ias->serial);
459 if (!signer && !(flags & PKCS7_NOINTERN) && p7->d.sign->cert)
460 signer =
461 X509_find_by_issuer_and_serial(p7->d.sign->cert,
462 ias->issuer, ias->serial);
463 if (!signer) {
464 PKCS7error(PKCS7_R_SIGNER_CERTIFICATE_NOT_FOUND);
465 sk_X509_free(signers);
466 return 0;
467 }
468
469 if (!sk_X509_push(signers, signer)) {
470 sk_X509_free(signers);
471 return NULL;
472 }
473 }
474 return signers;
475 }
476 LCRYPTO_ALIAS(PKCS7_get0_signers);
477
478 /* Build a complete PKCS#7 enveloped data */
479
480 PKCS7 *
PKCS7_encrypt(STACK_OF (X509)* certs,BIO * in,const EVP_CIPHER * cipher,int flags)481 PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher,
482 int flags)
483 {
484 PKCS7 *p7;
485 BIO *p7bio = NULL;
486 int i;
487 X509 *x509;
488
489 if (!(p7 = PKCS7_new())) {
490 PKCS7error(ERR_R_MALLOC_FAILURE);
491 return NULL;
492 }
493
494 if (!PKCS7_set_type(p7, NID_pkcs7_enveloped))
495 goto err;
496 if (!PKCS7_set_cipher(p7, cipher)) {
497 PKCS7error(PKCS7_R_ERROR_SETTING_CIPHER);
498 goto err;
499 }
500
501 for (i = 0; i < sk_X509_num(certs); i++) {
502 x509 = sk_X509_value(certs, i);
503 if (!PKCS7_add_recipient(p7, x509)) {
504 PKCS7error(PKCS7_R_ERROR_ADDING_RECIPIENT);
505 goto err;
506 }
507 }
508
509 if (flags & PKCS7_STREAM)
510 return p7;
511
512 if (PKCS7_final(p7, in, flags))
513 return p7;
514
515 err:
516 BIO_free_all(p7bio);
517 PKCS7_free(p7);
518 return NULL;
519 }
520 LCRYPTO_ALIAS(PKCS7_encrypt);
521
522 int
PKCS7_decrypt(PKCS7 * p7,EVP_PKEY * pkey,X509 * cert,BIO * data,int flags)523 PKCS7_decrypt(PKCS7 *p7, EVP_PKEY *pkey, X509 *cert, BIO *data, int flags)
524 {
525 BIO *tmpmem;
526 int ret, i;
527 char buf[4096];
528
529 if (!p7) {
530 PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
531 return 0;
532 }
533
534 if (!PKCS7_type_is_enveloped(p7)) {
535 PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE);
536 return 0;
537 }
538
539 if (cert && !X509_check_private_key(cert, pkey)) {
540 PKCS7error(PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
541 return 0;
542 }
543
544 if (!(tmpmem = PKCS7_dataDecode(p7, pkey, NULL, cert))) {
545 PKCS7error(PKCS7_R_DECRYPT_ERROR);
546 return 0;
547 }
548
549 if (flags & PKCS7_TEXT) {
550 BIO *tmpbuf;
551
552 /* Encrypt BIOs can't do BIO_gets() so add a buffer BIO */
553 if (!(tmpbuf = BIO_new(BIO_f_buffer()))) {
554 PKCS7error(ERR_R_MALLOC_FAILURE);
555 BIO_free_all(tmpmem);
556 return 0;
557 }
558 BIO_push(tmpbuf, tmpmem);
559 ret = SMIME_text(tmpbuf, data);
560 if (ret > 0 && BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) {
561 if (!BIO_get_cipher_status(tmpmem))
562 ret = 0;
563 }
564 BIO_free_all(tmpbuf);
565 return ret;
566 } else {
567 for (;;) {
568 i = BIO_read(tmpmem, buf, sizeof(buf));
569 if (i <= 0) {
570 ret = 1;
571 if (BIO_method_type(tmpmem) ==
572 BIO_TYPE_CIPHER) {
573 if (!BIO_get_cipher_status(tmpmem))
574 ret = 0;
575 }
576 break;
577 }
578 if (BIO_write(data, buf, i) != i) {
579 ret = 0;
580 break;
581 }
582 }
583 BIO_free_all(tmpmem);
584 return ret;
585 }
586 }
587 LCRYPTO_ALIAS(PKCS7_decrypt);
588