1 /*
2  * Copyright 1999-2016 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 /* Simple PKCS#7 processing functions */
11 
12 #include <stdio.h>
13 #include "internal/cryptlib.h"
14 #include <openssl/x509.h>
15 #include <openssl/x509v3.h>
16 
17 
18 #define BUFFERSIZE 4096
19 
20 static int pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si);
21 
22 PKCS7 *PKCS7_sign(X509 *signcert, EVP_PKEY *pkey, STACK_OF(X509) *certs,
23                   BIO *data, int flags)
24 {
25     PKCS7 *p7;
26     int i;
27 
28     if ((p7 = PKCS7_new()) == NULL) {
29         PKCS7err(PKCS7_F_PKCS7_SIGN, ERR_R_MALLOC_FAILURE);
30         return NULL;
31     }
32 
33     if (!PKCS7_set_type(p7, NID_pkcs7_signed))
34         goto err;
35 
36     if (!PKCS7_content_new(p7, NID_pkcs7_data))
37         goto err;
38 
39     if (pkey && !PKCS7_sign_add_signer(p7, signcert, pkey, NULL, flags)) {
40         PKCS7err(PKCS7_F_PKCS7_SIGN, PKCS7_R_PKCS7_ADD_SIGNER_ERROR);
41         goto err;
42     }
43 
44     if (!(flags & PKCS7_NOCERTS)) {
45         for (i = 0; i < sk_X509_num(certs); i++) {
46             if (!PKCS7_add_certificate(p7, sk_X509_value(certs, i)))
47                 goto err;
48         }
49     }
50 
51     if (flags & PKCS7_DETACHED)
52         PKCS7_set_detached(p7, 1);
53 
54     if (flags & (PKCS7_STREAM | PKCS7_PARTIAL))
55         return p7;
56 
57     if (PKCS7_final(p7, data, flags))
58         return p7;
59 
60  err:
61     PKCS7_free(p7);
62     return NULL;
63 }
64 
65 int PKCS7_final(PKCS7 *p7, BIO *data, int flags)
66 {
67     BIO *p7bio;
68     int ret = 0;
69 
70     if ((p7bio = PKCS7_dataInit(p7, NULL)) == NULL) {
71         PKCS7err(PKCS7_F_PKCS7_FINAL, ERR_R_MALLOC_FAILURE);
72         return 0;
73     }
74 
75     SMIME_crlf_copy(data, p7bio, flags);
76 
77     (void)BIO_flush(p7bio);
78 
79     if (!PKCS7_dataFinal(p7, p7bio)) {
80         PKCS7err(PKCS7_F_PKCS7_FINAL, PKCS7_R_PKCS7_DATASIGN);
81         goto err;
82     }
83 
84     ret = 1;
85 
86  err:
87     BIO_free_all(p7bio);
88 
89     return ret;
90 
91 }
92 
93 /* Check to see if a cipher exists and if so add S/MIME capabilities */
94 
95 static int add_cipher_smcap(STACK_OF(X509_ALGOR) *sk, int nid, int arg)
96 {
97     if (EVP_get_cipherbynid(nid))
98         return PKCS7_simple_smimecap(sk, nid, arg);
99     return 1;
100 }
101 
102 static int add_digest_smcap(STACK_OF(X509_ALGOR) *sk, int nid, int arg)
103 {
104     if (EVP_get_digestbynid(nid))
105         return PKCS7_simple_smimecap(sk, nid, arg);
106     return 1;
107 }
108 
109 PKCS7_SIGNER_INFO *PKCS7_sign_add_signer(PKCS7 *p7, X509 *signcert,
110                                          EVP_PKEY *pkey, const EVP_MD *md,
111                                          int flags)
112 {
113     PKCS7_SIGNER_INFO *si = NULL;
114     STACK_OF(X509_ALGOR) *smcap = NULL;
115     if (!X509_check_private_key(signcert, pkey)) {
116         PKCS7err(PKCS7_F_PKCS7_SIGN_ADD_SIGNER,
117                  PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
118         return NULL;
119     }
120 
121     if ((si = PKCS7_add_signature(p7, signcert, pkey, md)) == NULL) {
122         PKCS7err(PKCS7_F_PKCS7_SIGN_ADD_SIGNER,
123                  PKCS7_R_PKCS7_ADD_SIGNATURE_ERROR);
124         return NULL;
125     }
126 
127     if (!(flags & PKCS7_NOCERTS)) {
128         if (!PKCS7_add_certificate(p7, signcert))
129             goto err;
130     }
131 
132     if (!(flags & PKCS7_NOATTR)) {
133         if (!PKCS7_add_attrib_content_type(si, NULL))
134             goto err;
135         /* Add SMIMECapabilities */
136         if (!(flags & PKCS7_NOSMIMECAP)) {
137             if ((smcap = sk_X509_ALGOR_new_null()) == NULL) {
138                 PKCS7err(PKCS7_F_PKCS7_SIGN_ADD_SIGNER, ERR_R_MALLOC_FAILURE);
139                 goto err;
140             }
141             if (!add_cipher_smcap(smcap, NID_aes_256_cbc, -1)
142                 || !add_digest_smcap(smcap, NID_id_GostR3411_2012_256, -1)
143                 || !add_digest_smcap(smcap, NID_id_GostR3411_2012_512, -1)
144                 || !add_digest_smcap(smcap, NID_id_GostR3411_94, -1)
145                 || !add_cipher_smcap(smcap, NID_id_Gost28147_89, -1)
146                 || !add_cipher_smcap(smcap, NID_aes_192_cbc, -1)
147                 || !add_cipher_smcap(smcap, NID_aes_128_cbc, -1)
148                 || !add_cipher_smcap(smcap, NID_des_ede3_cbc, -1)
149                 || !add_cipher_smcap(smcap, NID_rc2_cbc, 128)
150                 || !add_cipher_smcap(smcap, NID_rc2_cbc, 64)
151                 || !add_cipher_smcap(smcap, NID_des_cbc, -1)
152                 || !add_cipher_smcap(smcap, NID_rc2_cbc, 40)
153                 || !PKCS7_add_attrib_smimecap(si, smcap))
154                 goto err;
155             sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free);
156             smcap = NULL;
157         }
158         if (flags & PKCS7_REUSE_DIGEST) {
159             if (!pkcs7_copy_existing_digest(p7, si))
160                 goto err;
161             if (!(flags & PKCS7_PARTIAL) && !PKCS7_SIGNER_INFO_sign(si))
162                 goto err;
163         }
164     }
165     return si;
166  err:
167     sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free);
168     return NULL;
169 }
170 
171 /*
172  * Search for a digest matching SignerInfo digest type and if found copy
173  * across.
174  */
175 
176 static int pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si)
177 {
178     int i;
179     STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
180     PKCS7_SIGNER_INFO *sitmp;
181     ASN1_OCTET_STRING *osdig = NULL;
182     sinfos = PKCS7_get_signer_info(p7);
183     for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
184         sitmp = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
185         if (si == sitmp)
186             break;
187         if (sk_X509_ATTRIBUTE_num(sitmp->auth_attr) <= 0)
188             continue;
189         if (!OBJ_cmp(si->digest_alg->algorithm, sitmp->digest_alg->algorithm)) {
190             osdig = PKCS7_digest_from_attributes(sitmp->auth_attr);
191             break;
192         }
193 
194     }
195 
196     if (osdig)
197         return PKCS7_add1_attrib_digest(si, osdig->data, osdig->length);
198 
199     PKCS7err(PKCS7_F_PKCS7_COPY_EXISTING_DIGEST,
200              PKCS7_R_NO_MATCHING_DIGEST_TYPE_FOUND);
201     return 0;
202 }
203 
204 int PKCS7_verify(PKCS7 *p7, STACK_OF(X509) *certs, X509_STORE *store,
205                  BIO *indata, BIO *out, int flags)
206 {
207     STACK_OF(X509) *signers;
208     X509 *signer;
209     STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
210     PKCS7_SIGNER_INFO *si;
211     X509_STORE_CTX *cert_ctx = NULL;
212     char *buf = NULL;
213     int i, j = 0, k, ret = 0;
214     BIO *p7bio = NULL;
215     BIO *tmpin = NULL, *tmpout = NULL;
216 
217     if (!p7) {
218         PKCS7err(PKCS7_F_PKCS7_VERIFY, PKCS7_R_INVALID_NULL_POINTER);
219         return 0;
220     }
221 
222     if (!PKCS7_type_is_signed(p7)) {
223         PKCS7err(PKCS7_F_PKCS7_VERIFY, PKCS7_R_WRONG_CONTENT_TYPE);
224         return 0;
225     }
226 
227     /* Check for no data and no content: no data to verify signature */
228     if (PKCS7_get_detached(p7) && !indata) {
229         PKCS7err(PKCS7_F_PKCS7_VERIFY, PKCS7_R_NO_CONTENT);
230         return 0;
231     }
232 
233     if (flags & PKCS7_NO_DUAL_CONTENT) {
234         /*
235          * This was originally "#if 0" because we thought that only old broken
236          * Netscape did this.  It turns out that Authenticode uses this kind
237          * of "extended" PKCS7 format, and things like UEFI secure boot and
238          * tools like osslsigncode need it.  In Authenticode the verification
239          * process is different, but the existing PKCs7 verification works.
240          */
241         if (!PKCS7_get_detached(p7) && indata) {
242             PKCS7err(PKCS7_F_PKCS7_VERIFY, PKCS7_R_CONTENT_AND_DATA_PRESENT);
243             return 0;
244         }
245     }
246 
247     sinfos = PKCS7_get_signer_info(p7);
248 
249     if (!sinfos || !sk_PKCS7_SIGNER_INFO_num(sinfos)) {
250         PKCS7err(PKCS7_F_PKCS7_VERIFY, PKCS7_R_NO_SIGNATURES_ON_DATA);
251         return 0;
252     }
253 
254     signers = PKCS7_get0_signers(p7, certs, flags);
255     if (!signers)
256         return 0;
257 
258     /* Now verify the certificates */
259 
260     cert_ctx = X509_STORE_CTX_new();
261     if (cert_ctx == NULL)
262         goto err;
263     if (!(flags & PKCS7_NOVERIFY))
264         for (k = 0; k < sk_X509_num(signers); k++) {
265             signer = sk_X509_value(signers, k);
266             if (!(flags & PKCS7_NOCHAIN)) {
267                 if (!X509_STORE_CTX_init(cert_ctx, store, signer,
268                                          p7->d.sign->cert)) {
269                     PKCS7err(PKCS7_F_PKCS7_VERIFY, ERR_R_X509_LIB);
270                     goto err;
271                 }
272                 X509_STORE_CTX_set_default(cert_ctx, "smime_sign");
273             } else if (!X509_STORE_CTX_init(cert_ctx, store, signer, NULL)) {
274                 PKCS7err(PKCS7_F_PKCS7_VERIFY, ERR_R_X509_LIB);
275                 goto err;
276             }
277             if (!(flags & PKCS7_NOCRL))
278                 X509_STORE_CTX_set0_crls(cert_ctx, p7->d.sign->crl);
279             i = X509_verify_cert(cert_ctx);
280             if (i <= 0)
281                 j = X509_STORE_CTX_get_error(cert_ctx);
282             X509_STORE_CTX_cleanup(cert_ctx);
283             if (i <= 0) {
284                 PKCS7err(PKCS7_F_PKCS7_VERIFY,
285                          PKCS7_R_CERTIFICATE_VERIFY_ERROR);
286                 ERR_add_error_data(2, "Verify error:",
287                                    X509_verify_cert_error_string(j));
288                 goto err;
289             }
290             /* Check for revocation status here */
291         }
292 
293     /*
294      * Performance optimization: if the content is a memory BIO then store
295      * its contents in a temporary read only memory BIO. This avoids
296      * potentially large numbers of slow copies of data which will occur when
297      * reading from a read write memory BIO when signatures are calculated.
298      */
299 
300     if (indata && (BIO_method_type(indata) == BIO_TYPE_MEM)) {
301         char *ptr;
302         long len;
303         len = BIO_get_mem_data(indata, &ptr);
304         tmpin = BIO_new_mem_buf(ptr, len);
305         if (tmpin == NULL) {
306             PKCS7err(PKCS7_F_PKCS7_VERIFY, ERR_R_MALLOC_FAILURE);
307             goto err;
308         }
309     } else
310         tmpin = indata;
311 
312     if ((p7bio = PKCS7_dataInit(p7, tmpin)) == NULL)
313         goto err;
314 
315     if (flags & PKCS7_TEXT) {
316         if ((tmpout = BIO_new(BIO_s_mem())) == NULL) {
317             PKCS7err(PKCS7_F_PKCS7_VERIFY, ERR_R_MALLOC_FAILURE);
318             goto err;
319         }
320         BIO_set_mem_eof_return(tmpout, 0);
321     } else
322         tmpout = out;
323 
324     /* We now have to 'read' from p7bio to calculate digests etc. */
325     if ((buf = OPENSSL_malloc(BUFFERSIZE)) == NULL) {
326         PKCS7err(PKCS7_F_PKCS7_VERIFY, ERR_R_MALLOC_FAILURE);
327         goto err;
328     }
329     for (;;) {
330         i = BIO_read(p7bio, buf, BUFFERSIZE);
331         if (i <= 0)
332             break;
333         if (tmpout)
334             BIO_write(tmpout, buf, i);
335     }
336 
337     if (flags & PKCS7_TEXT) {
338         if (!SMIME_text(tmpout, out)) {
339             PKCS7err(PKCS7_F_PKCS7_VERIFY, PKCS7_R_SMIME_TEXT_ERROR);
340             BIO_free(tmpout);
341             goto err;
342         }
343         BIO_free(tmpout);
344     }
345 
346     /* Now Verify All Signatures */
347     if (!(flags & PKCS7_NOSIGS))
348         for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
349             si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
350             signer = sk_X509_value(signers, i);
351             j = PKCS7_signatureVerify(p7bio, p7, si, signer);
352             if (j <= 0) {
353                 PKCS7err(PKCS7_F_PKCS7_VERIFY, PKCS7_R_SIGNATURE_FAILURE);
354                 goto err;
355             }
356         }
357 
358     ret = 1;
359 
360  err:
361     X509_STORE_CTX_free(cert_ctx);
362     OPENSSL_free(buf);
363     if (tmpin == indata) {
364         if (indata)
365             BIO_pop(p7bio);
366     }
367     BIO_free_all(p7bio);
368     sk_X509_free(signers);
369     return ret;
370 }
371 
372 STACK_OF(X509) *PKCS7_get0_signers(PKCS7 *p7, STACK_OF(X509) *certs,
373                                    int flags)
374 {
375     STACK_OF(X509) *signers;
376     STACK_OF(PKCS7_SIGNER_INFO) *sinfos;
377     PKCS7_SIGNER_INFO *si;
378     PKCS7_ISSUER_AND_SERIAL *ias;
379     X509 *signer;
380     int i;
381 
382     if (!p7) {
383         PKCS7err(PKCS7_F_PKCS7_GET0_SIGNERS, PKCS7_R_INVALID_NULL_POINTER);
384         return NULL;
385     }
386 
387     if (!PKCS7_type_is_signed(p7)) {
388         PKCS7err(PKCS7_F_PKCS7_GET0_SIGNERS, PKCS7_R_WRONG_CONTENT_TYPE);
389         return NULL;
390     }
391 
392     /* Collect all the signers together */
393 
394     sinfos = PKCS7_get_signer_info(p7);
395 
396     if (sk_PKCS7_SIGNER_INFO_num(sinfos) <= 0) {
397         PKCS7err(PKCS7_F_PKCS7_GET0_SIGNERS, PKCS7_R_NO_SIGNERS);
398         return 0;
399     }
400 
401     if ((signers = sk_X509_new_null()) == NULL) {
402         PKCS7err(PKCS7_F_PKCS7_GET0_SIGNERS, ERR_R_MALLOC_FAILURE);
403         return NULL;
404     }
405 
406     for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) {
407         si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);
408         ias = si->issuer_and_serial;
409         signer = NULL;
410         /* If any certificates passed they take priority */
411         if (certs)
412             signer = X509_find_by_issuer_and_serial(certs,
413                                                     ias->issuer, ias->serial);
414         if (!signer && !(flags & PKCS7_NOINTERN)
415             && p7->d.sign->cert)
416             signer =
417                 X509_find_by_issuer_and_serial(p7->d.sign->cert,
418                                                ias->issuer, ias->serial);
419         if (!signer) {
420             PKCS7err(PKCS7_F_PKCS7_GET0_SIGNERS,
421                      PKCS7_R_SIGNER_CERTIFICATE_NOT_FOUND);
422             sk_X509_free(signers);
423             return 0;
424         }
425 
426         if (!sk_X509_push(signers, signer)) {
427             sk_X509_free(signers);
428             return NULL;
429         }
430     }
431     return signers;
432 }
433 
434 /* Build a complete PKCS#7 enveloped data */
435 
436 PKCS7 *PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher,
437                      int flags)
438 {
439     PKCS7 *p7;
440     BIO *p7bio = NULL;
441     int i;
442     X509 *x509;
443     if ((p7 = PKCS7_new()) == NULL) {
444         PKCS7err(PKCS7_F_PKCS7_ENCRYPT, ERR_R_MALLOC_FAILURE);
445         return NULL;
446     }
447 
448     if (!PKCS7_set_type(p7, NID_pkcs7_enveloped))
449         goto err;
450     if (!PKCS7_set_cipher(p7, cipher)) {
451         PKCS7err(PKCS7_F_PKCS7_ENCRYPT, PKCS7_R_ERROR_SETTING_CIPHER);
452         goto err;
453     }
454 
455     for (i = 0; i < sk_X509_num(certs); i++) {
456         x509 = sk_X509_value(certs, i);
457         if (!PKCS7_add_recipient(p7, x509)) {
458             PKCS7err(PKCS7_F_PKCS7_ENCRYPT, PKCS7_R_ERROR_ADDING_RECIPIENT);
459             goto err;
460         }
461     }
462 
463     if (flags & PKCS7_STREAM)
464         return p7;
465 
466     if (PKCS7_final(p7, in, flags))
467         return p7;
468 
469  err:
470 
471     BIO_free_all(p7bio);
472     PKCS7_free(p7);
473     return NULL;
474 
475 }
476 
477 int PKCS7_decrypt(PKCS7 *p7, EVP_PKEY *pkey, X509 *cert, BIO *data, int flags)
478 {
479     BIO *tmpmem;
480     int ret = 0, i;
481     char *buf = NULL;
482 
483     if (!p7) {
484         PKCS7err(PKCS7_F_PKCS7_DECRYPT, PKCS7_R_INVALID_NULL_POINTER);
485         return 0;
486     }
487 
488     if (!PKCS7_type_is_enveloped(p7)) {
489         PKCS7err(PKCS7_F_PKCS7_DECRYPT, PKCS7_R_WRONG_CONTENT_TYPE);
490         return 0;
491     }
492 
493     if (cert && !X509_check_private_key(cert, pkey)) {
494         PKCS7err(PKCS7_F_PKCS7_DECRYPT,
495                  PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
496         return 0;
497     }
498 
499     if ((tmpmem = PKCS7_dataDecode(p7, pkey, NULL, cert)) == NULL) {
500         PKCS7err(PKCS7_F_PKCS7_DECRYPT, PKCS7_R_DECRYPT_ERROR);
501         return 0;
502     }
503 
504     if (flags & PKCS7_TEXT) {
505         BIO *tmpbuf, *bread;
506         /* Encrypt BIOs can't do BIO_gets() so add a buffer BIO */
507         if ((tmpbuf = BIO_new(BIO_f_buffer())) == NULL) {
508             PKCS7err(PKCS7_F_PKCS7_DECRYPT, ERR_R_MALLOC_FAILURE);
509             BIO_free_all(tmpmem);
510             return 0;
511         }
512         if ((bread = BIO_push(tmpbuf, tmpmem)) == NULL) {
513             PKCS7err(PKCS7_F_PKCS7_DECRYPT, ERR_R_MALLOC_FAILURE);
514             BIO_free_all(tmpbuf);
515             BIO_free_all(tmpmem);
516             return 0;
517         }
518         ret = SMIME_text(bread, data);
519         if (ret > 0 && BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) {
520             if (!BIO_get_cipher_status(tmpmem))
521                 ret = 0;
522         }
523         BIO_free_all(bread);
524         return ret;
525     }
526     if ((buf = OPENSSL_malloc(BUFFERSIZE)) == NULL) {
527         PKCS7err(PKCS7_F_PKCS7_DECRYPT, ERR_R_MALLOC_FAILURE);
528         goto err;
529     }
530     for (;;) {
531         i = BIO_read(tmpmem, buf, BUFFERSIZE);
532         if (i <= 0) {
533             ret = 1;
534             if (BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) {
535                 if (!BIO_get_cipher_status(tmpmem))
536                     ret = 0;
537             }
538 
539             break;
540         }
541         if (BIO_write(data, buf, i) != i) {
542             break;
543         }
544     }
545 err:
546     OPENSSL_free(buf);
547     BIO_free_all(tmpmem);
548     return ret;
549 }
550