1 // Copyright 1999-2016 The OpenSSL Project Authors. All Rights Reserved.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //     https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 #include <openssl/pkcs8.h>
16 
17 #include <limits.h>
18 
19 #include <openssl/asn1.h>
20 #include <openssl/asn1t.h>
21 #include <openssl/bio.h>
22 #include <openssl/buf.h>
23 #include <openssl/bytestring.h>
24 #include <openssl/digest.h>
25 #include <openssl/err.h>
26 #include <openssl/evp.h>
27 #include <openssl/hmac.h>
28 #include <openssl/mem.h>
29 #include <openssl/nid.h>
30 #include <openssl/rand.h>
31 #include <openssl/x509.h>
32 
33 #include "../bytestring/internal.h"
34 #include "../internal.h"
35 #include "../x509/internal.h"
36 #include "internal.h"
37 
38 
pkcs12_iterations_acceptable(uint64_t iterations)39 int pkcs12_iterations_acceptable(uint64_t iterations) {
40 #if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION)
41   static const uint64_t kIterationsLimit = 2048;
42 #else
43   // Windows imposes a limit of 600K. Mozilla say: “so them increasing
44   // maximum to something like 100M or 1G (to have few decades of breathing
45   // room) would be very welcome”[1]. So here we set the limit to 100M.
46   //
47   // [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1436873#c14
48   static const uint64_t kIterationsLimit = 100 * 1000000;
49 #endif
50 
51   assert(kIterationsLimit <= UINT32_MAX);
52   return 0 < iterations && iterations <= kIterationsLimit;
53 }
54 
ASN1_SEQUENCE(PKCS8_PRIV_KEY_INFO)55 ASN1_SEQUENCE(PKCS8_PRIV_KEY_INFO) = {
56     ASN1_SIMPLE(PKCS8_PRIV_KEY_INFO, version, ASN1_INTEGER),
57     ASN1_SIMPLE(PKCS8_PRIV_KEY_INFO, pkeyalg, X509_ALGOR),
58     ASN1_SIMPLE(PKCS8_PRIV_KEY_INFO, pkey, ASN1_OCTET_STRING),
59     ASN1_IMP_SET_OF_OPT(PKCS8_PRIV_KEY_INFO, attributes, X509_ATTRIBUTE, 0),
60 } ASN1_SEQUENCE_END(PKCS8_PRIV_KEY_INFO)
61 
62 IMPLEMENT_ASN1_FUNCTIONS_const(PKCS8_PRIV_KEY_INFO)
63 
64 EVP_PKEY *EVP_PKCS82PKEY(const PKCS8_PRIV_KEY_INFO *p8) {
65   uint8_t *der = NULL;
66   int der_len = i2d_PKCS8_PRIV_KEY_INFO(p8, &der);
67   if (der_len < 0) {
68     return NULL;
69   }
70 
71   CBS cbs;
72   CBS_init(&cbs, der, (size_t)der_len);
73   EVP_PKEY *ret = EVP_parse_private_key(&cbs);
74   if (ret == NULL || CBS_len(&cbs) != 0) {
75     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_DECODE_ERROR);
76     EVP_PKEY_free(ret);
77     OPENSSL_free(der);
78     return NULL;
79   }
80 
81   OPENSSL_free(der);
82   return ret;
83 }
84 
EVP_PKEY2PKCS8(const EVP_PKEY * pkey)85 PKCS8_PRIV_KEY_INFO *EVP_PKEY2PKCS8(const EVP_PKEY *pkey) {
86   CBB cbb;
87   uint8_t *der = NULL;
88   size_t der_len;
89   if (!CBB_init(&cbb, 0) || !EVP_marshal_private_key(&cbb, pkey) ||
90       !CBB_finish(&cbb, &der, &der_len) || der_len > LONG_MAX) {
91     CBB_cleanup(&cbb);
92     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_ENCODE_ERROR);
93     OPENSSL_free(der);
94     return NULL;
95   }
96 
97   const uint8_t *p = der;
98   PKCS8_PRIV_KEY_INFO *p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, &p, (long)der_len);
99   if (p8 == NULL || p != der + der_len) {
100     PKCS8_PRIV_KEY_INFO_free(p8);
101     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_DECODE_ERROR);
102     goto err;
103   }
104 
105   OPENSSL_free(der);
106   return p8;
107 
108 err:
109   OPENSSL_free(der);
110   return NULL;
111 }
112 
PKCS8_decrypt(X509_SIG * pkcs8,const char * pass,int pass_len_in)113 PKCS8_PRIV_KEY_INFO *PKCS8_decrypt(X509_SIG *pkcs8, const char *pass,
114                                    int pass_len_in) {
115   size_t pass_len;
116   if (pass_len_in == -1 && pass != NULL) {
117     pass_len = strlen(pass);
118   } else {
119     pass_len = (size_t)pass_len_in;
120   }
121 
122   PKCS8_PRIV_KEY_INFO *ret = NULL;
123   EVP_PKEY *pkey = NULL;
124   uint8_t *in = NULL;
125 
126   // Convert the legacy ASN.1 object to a byte string.
127   int in_len = i2d_X509_SIG(pkcs8, &in);
128   if (in_len < 0) {
129     goto err;
130   }
131 
132   CBS cbs;
133   CBS_init(&cbs, in, in_len);
134   pkey = PKCS8_parse_encrypted_private_key(&cbs, pass, pass_len);
135   if (pkey == NULL || CBS_len(&cbs) != 0) {
136     goto err;
137   }
138 
139   ret = EVP_PKEY2PKCS8(pkey);
140 
141 err:
142   OPENSSL_free(in);
143   EVP_PKEY_free(pkey);
144   return ret;
145 }
146 
PKCS8_encrypt(int pbe_nid,const EVP_CIPHER * cipher,const char * pass,int pass_len_in,const uint8_t * salt,size_t salt_len,int iterations,PKCS8_PRIV_KEY_INFO * p8inf)147 X509_SIG *PKCS8_encrypt(int pbe_nid, const EVP_CIPHER *cipher, const char *pass,
148                         int pass_len_in, const uint8_t *salt, size_t salt_len,
149                         int iterations, PKCS8_PRIV_KEY_INFO *p8inf) {
150   size_t pass_len;
151   if (pass_len_in == -1 && pass != NULL) {
152     pass_len = strlen(pass);
153   } else {
154     pass_len = (size_t)pass_len_in;
155   }
156 
157   // Parse out the private key.
158   EVP_PKEY *pkey = EVP_PKCS82PKEY(p8inf);
159   if (pkey == NULL) {
160     return NULL;
161   }
162 
163   X509_SIG *ret = NULL;
164   uint8_t *der = NULL;
165   const uint8_t *ptr;
166   size_t der_len;
167   CBB cbb;
168   if (!CBB_init(&cbb, 128) ||
169       !PKCS8_marshal_encrypted_private_key(&cbb, pbe_nid, cipher, pass,
170                                            pass_len, salt, salt_len, iterations,
171                                            pkey) ||
172       !CBB_finish(&cbb, &der, &der_len)) {
173     CBB_cleanup(&cbb);
174     goto err;
175   }
176 
177   // Convert back to legacy ASN.1 objects.
178   ptr = der;
179   ret = d2i_X509_SIG(NULL, &ptr, der_len);
180   if (ret == NULL || ptr != der + der_len) {
181     OPENSSL_PUT_ERROR(PKCS8, ERR_R_INTERNAL_ERROR);
182     X509_SIG_free(ret);
183     ret = NULL;
184   }
185 
186 err:
187   OPENSSL_free(der);
188   EVP_PKEY_free(pkey);
189   return ret;
190 }
191 
192 struct pkcs12_context {
193   EVP_PKEY **out_key;
194   STACK_OF(X509) *out_certs;
195   const char *password;
196   size_t password_len;
197 };
198 
199 // PKCS12_handle_sequence parses a BER-encoded SEQUENCE of elements in a PKCS#12
200 // structure.
PKCS12_handle_sequence(CBS * sequence,struct pkcs12_context * ctx,int (* handle_element)(CBS * cbs,struct pkcs12_context * ctx))201 static int PKCS12_handle_sequence(
202     CBS *sequence, struct pkcs12_context *ctx,
203     int (*handle_element)(CBS *cbs, struct pkcs12_context *ctx)) {
204   uint8_t *storage = NULL;
205   CBS in;
206   int ret = 0;
207 
208   // Although a BER->DER conversion is done at the beginning of |PKCS12_parse|,
209   // the ASN.1 data gets wrapped in OCTETSTRINGs and/or encrypted and the
210   // conversion cannot see through those wrappings. So each time we step
211   // through one we need to convert to DER again.
212   if (!CBS_asn1_ber_to_der(sequence, &in, &storage)) {
213     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
214     return 0;
215   }
216 
217   CBS child;
218   if (!CBS_get_asn1(&in, &child, CBS_ASN1_SEQUENCE) || CBS_len(&in) != 0) {
219     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
220     goto err;
221   }
222 
223   while (CBS_len(&child) > 0) {
224     CBS element;
225     if (!CBS_get_asn1(&child, &element, CBS_ASN1_SEQUENCE)) {
226       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
227       goto err;
228     }
229 
230     if (!handle_element(&element, ctx)) {
231       goto err;
232     }
233   }
234 
235   ret = 1;
236 
237 err:
238   OPENSSL_free(storage);
239   return ret;
240 }
241 
242 // 1.2.840.113549.1.12.10.1.1
243 static const uint8_t kKeyBag[] = {0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d,
244                                   0x01, 0x0c, 0x0a, 0x01, 0x01};
245 
246 // 1.2.840.113549.1.12.10.1.2
247 static const uint8_t kPKCS8ShroudedKeyBag[] = {
248     0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x0c, 0x0a, 0x01, 0x02};
249 
250 // 1.2.840.113549.1.12.10.1.3
251 static const uint8_t kCertBag[] = {0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d,
252                                    0x01, 0x0c, 0x0a, 0x01, 0x03};
253 
254 // 1.2.840.113549.1.9.20
255 static const uint8_t kFriendlyName[] = {0x2a, 0x86, 0x48, 0x86, 0xf7,
256                                         0x0d, 0x01, 0x09, 0x14};
257 
258 // 1.2.840.113549.1.9.21
259 static const uint8_t kLocalKeyID[] = {0x2a, 0x86, 0x48, 0x86, 0xf7,
260                                       0x0d, 0x01, 0x09, 0x15};
261 
262 // 1.2.840.113549.1.9.22.1
263 static const uint8_t kX509Certificate[] = {0x2a, 0x86, 0x48, 0x86, 0xf7,
264                                            0x0d, 0x01, 0x09, 0x16, 0x01};
265 
266 // parse_bag_attributes parses the bagAttributes field of a SafeBag structure.
267 // It sets |*out_friendly_name| to a newly-allocated copy of the friendly name,
268 // encoded as a UTF-8 string, or NULL if there is none. It returns one on
269 // success and zero on error.
parse_bag_attributes(CBS * attrs,uint8_t ** out_friendly_name,size_t * out_friendly_name_len)270 static int parse_bag_attributes(CBS *attrs, uint8_t **out_friendly_name,
271                                 size_t *out_friendly_name_len) {
272   *out_friendly_name = NULL;
273   *out_friendly_name_len = 0;
274 
275   // See https://tools.ietf.org/html/rfc7292#section-4.2.
276   while (CBS_len(attrs) != 0) {
277     CBS attr, oid, values;
278     if (!CBS_get_asn1(attrs, &attr, CBS_ASN1_SEQUENCE) ||
279         !CBS_get_asn1(&attr, &oid, CBS_ASN1_OBJECT) ||
280         !CBS_get_asn1(&attr, &values, CBS_ASN1_SET) || CBS_len(&attr) != 0) {
281       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
282       goto err;
283     }
284     if (CBS_mem_equal(&oid, kFriendlyName, sizeof(kFriendlyName))) {
285       // See https://tools.ietf.org/html/rfc2985, section 5.5.1.
286       CBS value;
287       if (*out_friendly_name != NULL ||
288           !CBS_get_asn1(&values, &value, CBS_ASN1_BMPSTRING) ||
289           CBS_len(&values) != 0 || CBS_len(&value) == 0) {
290         OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
291         goto err;
292       }
293       // Convert the friendly name to UTF-8.
294       CBB cbb;
295       if (!CBB_init(&cbb, CBS_len(&value))) {
296         goto err;
297       }
298       while (CBS_len(&value) != 0) {
299         uint32_t c;
300         if (!CBS_get_ucs2_be(&value, &c) || !CBB_add_utf8(&cbb, c)) {
301           OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_INVALID_CHARACTERS);
302           CBB_cleanup(&cbb);
303           goto err;
304         }
305       }
306       if (!CBB_finish(&cbb, out_friendly_name, out_friendly_name_len)) {
307         CBB_cleanup(&cbb);
308         goto err;
309       }
310     }
311   }
312 
313   return 1;
314 
315 err:
316   OPENSSL_free(*out_friendly_name);
317   *out_friendly_name = NULL;
318   *out_friendly_name_len = 0;
319   return 0;
320 }
321 
322 // PKCS12_handle_safe_bag parses a single SafeBag element in a PKCS#12
323 // structure.
PKCS12_handle_safe_bag(CBS * safe_bag,struct pkcs12_context * ctx)324 static int PKCS12_handle_safe_bag(CBS *safe_bag, struct pkcs12_context *ctx) {
325   CBS bag_id, wrapped_value, bag_attrs;
326   if (!CBS_get_asn1(safe_bag, &bag_id, CBS_ASN1_OBJECT) ||
327       !CBS_get_asn1(safe_bag, &wrapped_value,
328                     CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0)) {
329     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
330     return 0;
331   }
332   if (CBS_len(safe_bag) == 0) {
333     CBS_init(&bag_attrs, NULL, 0);
334   } else if (!CBS_get_asn1(safe_bag, &bag_attrs, CBS_ASN1_SET) ||
335              CBS_len(safe_bag) != 0) {
336     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
337     return 0;
338   }
339 
340   const int is_key_bag = CBS_mem_equal(&bag_id, kKeyBag, sizeof(kKeyBag));
341   const int is_shrouded_key_bag = CBS_mem_equal(&bag_id, kPKCS8ShroudedKeyBag,
342                                                 sizeof(kPKCS8ShroudedKeyBag));
343   if (is_key_bag || is_shrouded_key_bag) {
344     // See RFC 7292, section 4.2.1 and 4.2.2.
345     if (*ctx->out_key) {
346       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_MULTIPLE_PRIVATE_KEYS_IN_PKCS12);
347       return 0;
348     }
349 
350     EVP_PKEY *pkey =
351         is_key_bag ? EVP_parse_private_key(&wrapped_value)
352                    : PKCS8_parse_encrypted_private_key(
353                          &wrapped_value, ctx->password, ctx->password_len);
354     if (pkey == NULL) {
355       return 0;
356     }
357 
358     if (CBS_len(&wrapped_value) != 0) {
359       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
360       EVP_PKEY_free(pkey);
361       return 0;
362     }
363 
364     *ctx->out_key = pkey;
365     return 1;
366   }
367 
368   if (CBS_mem_equal(&bag_id, kCertBag, sizeof(kCertBag))) {
369     // See RFC 7292, section 4.2.3.
370     CBS cert_bag, cert_type, wrapped_cert, cert;
371     if (!CBS_get_asn1(&wrapped_value, &cert_bag, CBS_ASN1_SEQUENCE) ||
372         !CBS_get_asn1(&cert_bag, &cert_type, CBS_ASN1_OBJECT) ||
373         !CBS_get_asn1(&cert_bag, &wrapped_cert,
374                       CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0) ||
375         !CBS_get_asn1(&wrapped_cert, &cert, CBS_ASN1_OCTETSTRING)) {
376       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
377       return 0;
378     }
379 
380     // Skip unknown certificate types.
381     if (!CBS_mem_equal(&cert_type, kX509Certificate,
382                        sizeof(kX509Certificate))) {
383       return 1;
384     }
385 
386     if (CBS_len(&cert) > LONG_MAX) {
387       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
388       return 0;
389     }
390 
391     const uint8_t *inp = CBS_data(&cert);
392     X509 *x509 = d2i_X509(NULL, &inp, (long)CBS_len(&cert));
393     if (!x509) {
394       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
395       return 0;
396     }
397 
398     if (inp != CBS_data(&cert) + CBS_len(&cert)) {
399       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
400       X509_free(x509);
401       return 0;
402     }
403 
404     uint8_t *friendly_name;
405     size_t friendly_name_len;
406     if (!parse_bag_attributes(&bag_attrs, &friendly_name, &friendly_name_len)) {
407       X509_free(x509);
408       return 0;
409     }
410     int ok = friendly_name_len == 0 ||
411              X509_alias_set1(x509, friendly_name, friendly_name_len);
412     OPENSSL_free(friendly_name);
413     if (!ok || 0 == sk_X509_push(ctx->out_certs, x509)) {
414       X509_free(x509);
415       return 0;
416     }
417 
418     return 1;
419   }
420 
421   // Unknown element type - ignore it.
422   return 1;
423 }
424 
425 // 1.2.840.113549.1.7.1
426 static const uint8_t kPKCS7Data[] = {0x2a, 0x86, 0x48, 0x86, 0xf7,
427                                      0x0d, 0x01, 0x07, 0x01};
428 
429 // 1.2.840.113549.1.7.6
430 static const uint8_t kPKCS7EncryptedData[] = {0x2a, 0x86, 0x48, 0x86, 0xf7,
431                                               0x0d, 0x01, 0x07, 0x06};
432 
433 // PKCS12_handle_content_info parses a single PKCS#7 ContentInfo element in a
434 // PKCS#12 structure.
PKCS12_handle_content_info(CBS * content_info,struct pkcs12_context * ctx)435 static int PKCS12_handle_content_info(CBS *content_info,
436                                       struct pkcs12_context *ctx) {
437   CBS content_type, wrapped_contents, contents;
438   int ret = 0;
439   uint8_t *storage = NULL;
440 
441   if (!CBS_get_asn1(content_info, &content_type, CBS_ASN1_OBJECT) ||
442       !CBS_get_asn1(content_info, &wrapped_contents,
443                     CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0) ||
444       CBS_len(content_info) != 0) {
445     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
446     goto err;
447   }
448 
449   if (CBS_mem_equal(&content_type, kPKCS7EncryptedData,
450                     sizeof(kPKCS7EncryptedData))) {
451     // See https://tools.ietf.org/html/rfc2315#section-13.
452     //
453     // PKCS#7 encrypted data inside a PKCS#12 structure is generally an
454     // encrypted certificate bag and it's generally encrypted with 40-bit
455     // RC2-CBC.
456     CBS version_bytes, eci, contents_type, ai, encrypted_contents;
457     uint8_t *out;
458     size_t out_len;
459 
460     if (!CBS_get_asn1(&wrapped_contents, &contents, CBS_ASN1_SEQUENCE) ||
461         !CBS_get_asn1(&contents, &version_bytes, CBS_ASN1_INTEGER) ||
462         // EncryptedContentInfo, see
463         // https://tools.ietf.org/html/rfc2315#section-10.1
464         !CBS_get_asn1(&contents, &eci, CBS_ASN1_SEQUENCE) ||
465         !CBS_get_asn1(&eci, &contents_type, CBS_ASN1_OBJECT) ||
466         // AlgorithmIdentifier, see
467         // https://tools.ietf.org/html/rfc5280#section-4.1.1.2
468         !CBS_get_asn1(&eci, &ai, CBS_ASN1_SEQUENCE) ||
469         !CBS_get_asn1_implicit_string(&eci, &encrypted_contents, &storage,
470                                       CBS_ASN1_CONTEXT_SPECIFIC | 0,
471                                       CBS_ASN1_OCTETSTRING)) {
472       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
473       goto err;
474     }
475 
476     if (!CBS_mem_equal(&contents_type, kPKCS7Data, sizeof(kPKCS7Data))) {
477       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
478       goto err;
479     }
480 
481     if (!pkcs8_pbe_decrypt(&out, &out_len, &ai, ctx->password,
482                            ctx->password_len, CBS_data(&encrypted_contents),
483                            CBS_len(&encrypted_contents))) {
484       goto err;
485     }
486 
487     CBS safe_contents;
488     CBS_init(&safe_contents, out, out_len);
489     ret = PKCS12_handle_sequence(&safe_contents, ctx, PKCS12_handle_safe_bag);
490     OPENSSL_free(out);
491   } else if (CBS_mem_equal(&content_type, kPKCS7Data, sizeof(kPKCS7Data))) {
492     CBS octet_string_contents;
493 
494     if (!CBS_get_asn1(&wrapped_contents, &octet_string_contents,
495                       CBS_ASN1_OCTETSTRING)) {
496       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
497       goto err;
498     }
499 
500     ret = PKCS12_handle_sequence(&octet_string_contents, ctx,
501                                  PKCS12_handle_safe_bag);
502   } else {
503     // Unknown element type - ignore it.
504     ret = 1;
505   }
506 
507 err:
508   OPENSSL_free(storage);
509   return ret;
510 }
511 
pkcs12_check_mac(int * out_mac_ok,const char * password,size_t password_len,const CBS * salt,uint32_t iterations,const EVP_MD * md,const CBS * authsafes,const CBS * expected_mac)512 static int pkcs12_check_mac(int *out_mac_ok, const char *password,
513                             size_t password_len, const CBS *salt,
514                             uint32_t iterations, const EVP_MD *md,
515                             const CBS *authsafes, const CBS *expected_mac) {
516   int ret = 0;
517   uint8_t hmac_key[EVP_MAX_MD_SIZE];
518   if (!pkcs12_key_gen(password, password_len, CBS_data(salt), CBS_len(salt),
519                       PKCS12_MAC_ID, iterations, EVP_MD_size(md), hmac_key,
520                       md)) {
521     goto err;
522   }
523 
524   uint8_t hmac[EVP_MAX_MD_SIZE];
525   unsigned hmac_len;
526   if (NULL == HMAC(md, hmac_key, EVP_MD_size(md), CBS_data(authsafes),
527                    CBS_len(authsafes), hmac, &hmac_len)) {
528     goto err;
529   }
530 
531   *out_mac_ok = CBS_mem_equal(expected_mac, hmac, hmac_len);
532   if (CRYPTO_fuzzer_mode_enabled()) {
533     *out_mac_ok = 1;
534   }
535   ret = 1;
536 
537 err:
538   OPENSSL_cleanse(hmac_key, sizeof(hmac_key));
539   return ret;
540 }
541 
542 
PKCS12_get_key_and_certs(EVP_PKEY ** out_key,STACK_OF (X509)* out_certs,CBS * ber_in,const char * password)543 int PKCS12_get_key_and_certs(EVP_PKEY **out_key, STACK_OF(X509) *out_certs,
544                              CBS *ber_in, const char *password) {
545   uint8_t *storage = NULL;
546   CBS in, pfx, mac_data, authsafe, content_type, wrapped_authsafes, authsafes;
547   uint64_t version;
548   int ret = 0;
549   struct pkcs12_context ctx;
550   const size_t original_out_certs_len = sk_X509_num(out_certs);
551 
552   // The input may be in BER format.
553   if (!CBS_asn1_ber_to_der(ber_in, &in, &storage)) {
554     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
555     return 0;
556   }
557 
558   *out_key = NULL;
559   OPENSSL_memset(&ctx, 0, sizeof(ctx));
560 
561   // See ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-12/pkcs-12v1.pdf, section
562   // four.
563   if (!CBS_get_asn1(&in, &pfx, CBS_ASN1_SEQUENCE) || CBS_len(&in) != 0 ||
564       !CBS_get_asn1_uint64(&pfx, &version)) {
565     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
566     goto err;
567   }
568 
569   if (version < 3) {
570     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_VERSION);
571     goto err;
572   }
573 
574   if (!CBS_get_asn1(&pfx, &authsafe, CBS_ASN1_SEQUENCE)) {
575     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
576     goto err;
577   }
578 
579   if (CBS_len(&pfx) == 0) {
580     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_MISSING_MAC);
581     goto err;
582   }
583 
584   if (!CBS_get_asn1(&pfx, &mac_data, CBS_ASN1_SEQUENCE)) {
585     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
586     goto err;
587   }
588 
589   // authsafe is a PKCS#7 ContentInfo. See
590   // https://tools.ietf.org/html/rfc2315#section-7.
591   if (!CBS_get_asn1(&authsafe, &content_type, CBS_ASN1_OBJECT) ||
592       !CBS_get_asn1(&authsafe, &wrapped_authsafes,
593                     CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0)) {
594     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
595     goto err;
596   }
597 
598   // The content type can either be data or signedData. The latter indicates
599   // that it's signed by a public key, which isn't supported.
600   if (!CBS_mem_equal(&content_type, kPKCS7Data, sizeof(kPKCS7Data))) {
601     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_PKCS12_PUBLIC_KEY_INTEGRITY_NOT_SUPPORTED);
602     goto err;
603   }
604 
605   if (!CBS_get_asn1(&wrapped_authsafes, &authsafes, CBS_ASN1_OCTETSTRING)) {
606     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
607     goto err;
608   }
609 
610   ctx.out_key = out_key;
611   ctx.out_certs = out_certs;
612   ctx.password = password;
613   ctx.password_len = password != NULL ? strlen(password) : 0;
614 
615   // Verify the MAC.
616   {
617     CBS mac, salt, expected_mac;
618     if (!CBS_get_asn1(&mac_data, &mac, CBS_ASN1_SEQUENCE)) {
619       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
620       goto err;
621     }
622 
623     const EVP_MD *md = EVP_parse_digest_algorithm(&mac);
624     if (md == NULL) {
625       goto err;
626     }
627 
628     if (!CBS_get_asn1(&mac, &expected_mac, CBS_ASN1_OCTETSTRING) ||
629         !CBS_get_asn1(&mac_data, &salt, CBS_ASN1_OCTETSTRING)) {
630       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
631       goto err;
632     }
633 
634     // The iteration count is optional and the default is one.
635     uint32_t iterations = 1;
636     if (CBS_len(&mac_data) > 0) {
637       uint64_t iterations_u64;
638       if (!CBS_get_asn1_uint64(&mac_data, &iterations_u64) ||
639           !pkcs12_iterations_acceptable(iterations_u64)) {
640         OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_BAD_PKCS12_DATA);
641         goto err;
642       }
643       iterations = (uint32_t)iterations_u64;
644     }
645 
646     int mac_ok;
647     if (!pkcs12_check_mac(&mac_ok, ctx.password, ctx.password_len, &salt,
648                           iterations, md, &authsafes, &expected_mac)) {
649       goto err;
650     }
651     if (!mac_ok && ctx.password_len == 0) {
652       // PKCS#12 encodes passwords as NUL-terminated UCS-2, so the empty
653       // password is encoded as {0, 0}. Some implementations use the empty byte
654       // array for "no password". OpenSSL considers a non-NULL password as {0,
655       // 0} and a NULL password as {}. It then, in high-level PKCS#12 parsing
656       // code, tries both options. We match this behavior.
657       ctx.password = ctx.password != NULL ? NULL : "";
658       if (!pkcs12_check_mac(&mac_ok, ctx.password, ctx.password_len, &salt,
659                             iterations, md, &authsafes, &expected_mac)) {
660         goto err;
661       }
662     }
663     if (!mac_ok) {
664       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_INCORRECT_PASSWORD);
665       goto err;
666     }
667   }
668 
669   // authsafes contains a series of PKCS#7 ContentInfos.
670   if (!PKCS12_handle_sequence(&authsafes, &ctx, PKCS12_handle_content_info)) {
671     goto err;
672   }
673 
674   ret = 1;
675 
676 err:
677   OPENSSL_free(storage);
678   if (!ret) {
679     EVP_PKEY_free(*out_key);
680     *out_key = NULL;
681     while (sk_X509_num(out_certs) > original_out_certs_len) {
682       X509 *x509 = sk_X509_pop(out_certs);
683       X509_free(x509);
684     }
685   }
686 
687   return ret;
688 }
689 
PKCS12_PBE_add(void)690 void PKCS12_PBE_add(void) {}
691 
692 struct pkcs12_st {
693   uint8_t *ber_bytes;
694   size_t ber_len;
695 };
696 
d2i_PKCS12(PKCS12 ** out_p12,const uint8_t ** ber_bytes,size_t ber_len)697 PKCS12 *d2i_PKCS12(PKCS12 **out_p12, const uint8_t **ber_bytes,
698                    size_t ber_len) {
699   PKCS12 *p12 = reinterpret_cast<PKCS12 *>(OPENSSL_malloc(sizeof(PKCS12)));
700   if (!p12) {
701     return NULL;
702   }
703 
704   p12->ber_bytes =
705       reinterpret_cast<uint8_t *>(OPENSSL_memdup(*ber_bytes, ber_len));
706   if (!p12->ber_bytes) {
707     OPENSSL_free(p12);
708     return NULL;
709   }
710 
711   p12->ber_len = ber_len;
712   *ber_bytes += ber_len;
713 
714   if (out_p12) {
715     PKCS12_free(*out_p12);
716     *out_p12 = p12;
717   }
718 
719   return p12;
720 }
721 
d2i_PKCS12_bio(BIO * bio,PKCS12 ** out_p12)722 PKCS12 *d2i_PKCS12_bio(BIO *bio, PKCS12 **out_p12) {
723   size_t used = 0;
724   BUF_MEM *buf;
725   const uint8_t *dummy;
726   static const size_t kMaxSize = 256 * 1024;
727   PKCS12 *ret = NULL;
728 
729   buf = BUF_MEM_new();
730   if (buf == NULL) {
731     return NULL;
732   }
733   if (BUF_MEM_grow(buf, 8192) == 0) {
734     goto out;
735   }
736 
737   for (;;) {
738     size_t max_read = buf->length - used;
739     int n = BIO_read(bio, &buf->data[used],
740                      max_read > INT_MAX ? INT_MAX : (int)max_read);
741     if (n < 0) {
742       if (used == 0) {
743         goto out;
744       }
745       // Workaround a bug in node.js. It uses a memory BIO for this in the wrong
746       // mode.
747       n = 0;
748     }
749 
750     if (n == 0) {
751       break;
752     }
753     used += n;
754 
755     if (used < buf->length) {
756       continue;
757     }
758 
759     if (buf->length > kMaxSize || BUF_MEM_grow(buf, buf->length * 2) == 0) {
760       goto out;
761     }
762   }
763 
764   dummy = (uint8_t *)buf->data;
765   ret = d2i_PKCS12(out_p12, &dummy, used);
766 
767 out:
768   BUF_MEM_free(buf);
769   return ret;
770 }
771 
d2i_PKCS12_fp(FILE * fp,PKCS12 ** out_p12)772 PKCS12 *d2i_PKCS12_fp(FILE *fp, PKCS12 **out_p12) {
773   BIO *bio;
774   PKCS12 *ret;
775 
776   bio = BIO_new_fp(fp, 0 /* don't take ownership */);
777   if (!bio) {
778     return NULL;
779   }
780 
781   ret = d2i_PKCS12_bio(bio, out_p12);
782   BIO_free(bio);
783   return ret;
784 }
785 
i2d_PKCS12(const PKCS12 * p12,uint8_t ** out)786 int i2d_PKCS12(const PKCS12 *p12, uint8_t **out) {
787   if (p12->ber_len > INT_MAX) {
788     OPENSSL_PUT_ERROR(PKCS8, ERR_R_OVERFLOW);
789     return -1;
790   }
791 
792   if (out == NULL) {
793     return (int)p12->ber_len;
794   }
795 
796   if (*out == NULL) {
797     *out = reinterpret_cast<uint8_t *>(
798         OPENSSL_memdup(p12->ber_bytes, p12->ber_len));
799     if (*out == NULL) {
800       return -1;
801     }
802   } else {
803     OPENSSL_memcpy(*out, p12->ber_bytes, p12->ber_len);
804     *out += p12->ber_len;
805   }
806   return (int)p12->ber_len;
807 }
808 
i2d_PKCS12_bio(BIO * bio,const PKCS12 * p12)809 int i2d_PKCS12_bio(BIO *bio, const PKCS12 *p12) {
810   return BIO_write_all(bio, p12->ber_bytes, p12->ber_len);
811 }
812 
i2d_PKCS12_fp(FILE * fp,const PKCS12 * p12)813 int i2d_PKCS12_fp(FILE *fp, const PKCS12 *p12) {
814   BIO *bio = BIO_new_fp(fp, 0 /* don't take ownership */);
815   if (bio == NULL) {
816     return 0;
817   }
818 
819   int ret = i2d_PKCS12_bio(bio, p12);
820   BIO_free(bio);
821   return ret;
822 }
823 
PKCS12_parse(const PKCS12 * p12,const char * password,EVP_PKEY ** out_pkey,X509 ** out_cert,STACK_OF (X509)** out_ca_certs)824 int PKCS12_parse(const PKCS12 *p12, const char *password, EVP_PKEY **out_pkey,
825                  X509 **out_cert, STACK_OF(X509) **out_ca_certs) {
826   CBS ber_bytes;
827   STACK_OF(X509) *ca_certs = NULL;
828   char ca_certs_alloced = 0;
829 
830   if (out_ca_certs != NULL && *out_ca_certs != NULL) {
831     ca_certs = *out_ca_certs;
832   }
833 
834   if (!ca_certs) {
835     ca_certs = sk_X509_new_null();
836     if (ca_certs == NULL) {
837       return 0;
838     }
839     ca_certs_alloced = 1;
840   }
841 
842   CBS_init(&ber_bytes, p12->ber_bytes, p12->ber_len);
843   if (!PKCS12_get_key_and_certs(out_pkey, ca_certs, &ber_bytes, password)) {
844     if (ca_certs_alloced) {
845       sk_X509_free(ca_certs);
846     }
847     return 0;
848   }
849 
850   // OpenSSL selects the last certificate which matches the private key as
851   // |out_cert|.
852   *out_cert = NULL;
853   size_t num_certs = sk_X509_num(ca_certs);
854   if (*out_pkey != NULL && num_certs > 0) {
855     for (size_t i = num_certs - 1; i < num_certs; i--) {
856       X509 *cert = sk_X509_value(ca_certs, i);
857       if (X509_check_private_key(cert, *out_pkey)) {
858         *out_cert = cert;
859         sk_X509_delete(ca_certs, i);
860         break;
861       }
862       ERR_clear_error();
863     }
864   }
865 
866   if (out_ca_certs) {
867     *out_ca_certs = ca_certs;
868   } else {
869     sk_X509_pop_free(ca_certs, X509_free);
870   }
871 
872   return 1;
873 }
874 
PKCS12_verify_mac(const PKCS12 * p12,const char * password,int password_len)875 int PKCS12_verify_mac(const PKCS12 *p12, const char *password,
876                       int password_len) {
877   if (password == NULL) {
878     if (password_len != 0) {
879       return 0;
880     }
881   } else if (password_len != -1 &&
882              (password[password_len] != 0 ||
883               OPENSSL_memchr(password, 0, password_len) != NULL)) {
884     return 0;
885   }
886 
887   EVP_PKEY *pkey = NULL;
888   X509 *cert = NULL;
889   if (!PKCS12_parse(p12, password, &pkey, &cert, NULL)) {
890     ERR_clear_error();
891     return 0;
892   }
893 
894   EVP_PKEY_free(pkey);
895   X509_free(cert);
896 
897   return 1;
898 }
899 
900 // add_bag_attributes adds the bagAttributes field of a SafeBag structure,
901 // containing the specified friendlyName and localKeyId attributes.
add_bag_attributes(CBB * bag,const char * name,size_t name_len,const uint8_t * key_id,size_t key_id_len)902 static int add_bag_attributes(CBB *bag, const char *name, size_t name_len,
903                               const uint8_t *key_id, size_t key_id_len) {
904   if (name == NULL && key_id_len == 0) {
905     return 1;  // Omit the OPTIONAL SET.
906   }
907   // See https://tools.ietf.org/html/rfc7292#section-4.2.
908   CBB attrs, attr, values, value;
909   if (!CBB_add_asn1(bag, &attrs, CBS_ASN1_SET)) {
910     return 0;
911   }
912   if (name_len != 0) {
913     // See https://tools.ietf.org/html/rfc2985, section 5.5.1.
914     if (!CBB_add_asn1(&attrs, &attr, CBS_ASN1_SEQUENCE) ||
915         !CBB_add_asn1_element(&attr, CBS_ASN1_OBJECT, kFriendlyName,
916                               sizeof(kFriendlyName)) ||
917         !CBB_add_asn1(&attr, &values, CBS_ASN1_SET) ||
918         !CBB_add_asn1(&values, &value, CBS_ASN1_BMPSTRING)) {
919       return 0;
920     }
921     // Convert the friendly name to a BMPString.
922     CBS name_cbs;
923     CBS_init(&name_cbs, (const uint8_t *)name, name_len);
924     while (CBS_len(&name_cbs) != 0) {
925       uint32_t c;
926       if (!CBS_get_utf8(&name_cbs, &c) || !CBB_add_ucs2_be(&value, c)) {
927         OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_INVALID_CHARACTERS);
928         return 0;
929       }
930     }
931   }
932   if (key_id_len != 0) {
933     // See https://tools.ietf.org/html/rfc2985, section 5.5.2.
934     if (!CBB_add_asn1(&attrs, &attr, CBS_ASN1_SEQUENCE) ||
935         !CBB_add_asn1_element(&attr, CBS_ASN1_OBJECT, kLocalKeyID,
936                               sizeof(kLocalKeyID)) ||
937         !CBB_add_asn1(&attr, &values, CBS_ASN1_SET) ||
938         !CBB_add_asn1_octet_string(&values, key_id, key_id_len)) {
939       return 0;
940     }
941   }
942   return CBB_flush_asn1_set_of(&attrs) && CBB_flush(bag);
943 }
944 
add_cert_bag(CBB * cbb,X509 * cert,const char * name,const uint8_t * key_id,size_t key_id_len)945 static int add_cert_bag(CBB *cbb, X509 *cert, const char *name,
946                         const uint8_t *key_id, size_t key_id_len) {
947   CBB bag, bag_contents, cert_bag, wrapped_cert, cert_value;
948   if (  // See https://tools.ietf.org/html/rfc7292#section-4.2.
949       !CBB_add_asn1(cbb, &bag, CBS_ASN1_SEQUENCE) ||
950       !CBB_add_asn1_element(&bag, CBS_ASN1_OBJECT, kCertBag,
951                             sizeof(kCertBag)) ||
952       !CBB_add_asn1(&bag, &bag_contents,
953                     CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 0) ||
954       // See https://tools.ietf.org/html/rfc7292#section-4.2.3.
955       !CBB_add_asn1(&bag_contents, &cert_bag, CBS_ASN1_SEQUENCE) ||
956       !CBB_add_asn1_element(&cert_bag, CBS_ASN1_OBJECT, kX509Certificate,
957                             sizeof(kX509Certificate)) ||
958       !CBB_add_asn1(&cert_bag, &wrapped_cert,
959                     CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 0) ||
960       !CBB_add_asn1(&wrapped_cert, &cert_value, CBS_ASN1_OCTETSTRING)) {
961     return 0;
962   }
963   uint8_t *buf;
964   int len = i2d_X509(cert, NULL);
965 
966   int int_name_len = 0;
967   const char *cert_name = (const char *)X509_alias_get0(cert, &int_name_len);
968   size_t name_len = int_name_len;
969   if (name) {
970     if (name_len != 0) {
971       OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_AMBIGUOUS_FRIENDLY_NAME);
972       return 0;
973     }
974     name_len = strlen(name);
975   } else {
976     name = cert_name;
977   }
978 
979   if (len < 0 || !CBB_add_space(&cert_value, &buf, (size_t)len) ||
980       i2d_X509(cert, &buf) < 0 ||
981       !add_bag_attributes(&bag, name, name_len, key_id, key_id_len) ||
982       !CBB_flush(cbb)) {
983     return 0;
984   }
985   return 1;
986 }
987 
add_cert_safe_contents(CBB * cbb,X509 * cert,const STACK_OF (X509)* chain,const char * name,const uint8_t * key_id,size_t key_id_len)988 static int add_cert_safe_contents(CBB *cbb, X509 *cert,
989                                   const STACK_OF(X509) *chain, const char *name,
990                                   const uint8_t *key_id, size_t key_id_len) {
991   CBB safe_contents;
992   if (!CBB_add_asn1(cbb, &safe_contents, CBS_ASN1_SEQUENCE) ||
993       (cert != NULL &&
994        !add_cert_bag(&safe_contents, cert, name, key_id, key_id_len))) {
995     return 0;
996   }
997 
998   for (size_t i = 0; i < sk_X509_num(chain); i++) {
999     // Only the leaf certificate gets attributes.
1000     if (!add_cert_bag(&safe_contents, sk_X509_value(chain, i), NULL, NULL, 0)) {
1001       return 0;
1002     }
1003   }
1004 
1005   return CBB_flush(cbb);
1006 }
1007 
1008 // add_encrypted_data encrypts |in| with |pbe_nid| and |pbe_cipher|, writing the
1009 // result to |out|. It returns one on success and zero on error. |pbe_nid| and
1010 // |pbe_cipher| are interpreted as in |PKCS8_encrypt|.
add_encrypted_data(CBB * out,int pbe_nid,const EVP_CIPHER * pbe_cipher,const char * password,size_t password_len,uint32_t iterations,const uint8_t * in,size_t in_len)1011 static int add_encrypted_data(CBB *out, int pbe_nid,
1012                               const EVP_CIPHER *pbe_cipher,
1013                               const char *password, size_t password_len,
1014                               uint32_t iterations, const uint8_t *in,
1015                               size_t in_len) {
1016   uint8_t salt[PKCS5_SALT_LEN];
1017   if (!RAND_bytes(salt, sizeof(salt))) {
1018     return 0;
1019   }
1020 
1021   bssl::ScopedEVP_CIPHER_CTX ctx;
1022   CBB content_info, wrapper, encrypted_data, encrypted_content_info,
1023       encrypted_content;
1024   if (  // Add the ContentInfo wrapping.
1025       !CBB_add_asn1(out, &content_info, CBS_ASN1_SEQUENCE) ||
1026       !CBB_add_asn1_element(&content_info, CBS_ASN1_OBJECT, kPKCS7EncryptedData,
1027                             sizeof(kPKCS7EncryptedData)) ||
1028       !CBB_add_asn1(&content_info, &wrapper,
1029                     CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 0) ||
1030       // See https://tools.ietf.org/html/rfc2315#section-13.
1031       !CBB_add_asn1(&wrapper, &encrypted_data, CBS_ASN1_SEQUENCE) ||
1032       !CBB_add_asn1_uint64(&encrypted_data, 0 /* version */) ||
1033       // See https://tools.ietf.org/html/rfc2315#section-10.1.
1034       !CBB_add_asn1(&encrypted_data, &encrypted_content_info,
1035                     CBS_ASN1_SEQUENCE) ||
1036       !CBB_add_asn1_element(&encrypted_content_info, CBS_ASN1_OBJECT,
1037                             kPKCS7Data, sizeof(kPKCS7Data)) ||
1038       // Set up encryption and fill in contentEncryptionAlgorithm.
1039       !pkcs12_pbe_encrypt_init(&encrypted_content_info, ctx.get(), pbe_nid,
1040                                pbe_cipher, iterations, password, password_len,
1041                                salt, sizeof(salt)) ||
1042       // Note this tag is primitive. It is an implicitly-tagged OCTET_STRING, so
1043       // it inherits the inner tag's constructed bit.
1044       !CBB_add_asn1(&encrypted_content_info, &encrypted_content,
1045                     CBS_ASN1_CONTEXT_SPECIFIC | 0)) {
1046     return 0;
1047   }
1048 
1049   size_t max_out = in_len + EVP_CIPHER_CTX_block_size(ctx.get());
1050   if (max_out < in_len) {
1051     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_TOO_LONG);
1052     return 0;
1053   }
1054 
1055   uint8_t *ptr;
1056   int n1, n2;
1057   if (!CBB_reserve(&encrypted_content, &ptr, max_out) ||
1058       !EVP_CipherUpdate(ctx.get(), ptr, &n1, in, in_len) ||
1059       !EVP_CipherFinal_ex(ctx.get(), ptr + n1, &n2) ||
1060       !CBB_did_write(&encrypted_content, n1 + n2) || !CBB_flush(out)) {
1061     return 0;
1062   }
1063 
1064   return 1;
1065 }
1066 
PKCS12_create(const char * password,const char * name,const EVP_PKEY * pkey,X509 * cert,const STACK_OF (X509)* chain,int key_nid,int cert_nid,int iterations,int mac_iterations,int key_type)1067 PKCS12 *PKCS12_create(const char *password, const char *name,
1068                       const EVP_PKEY *pkey, X509 *cert,
1069                       const STACK_OF(X509) *chain, int key_nid, int cert_nid,
1070                       int iterations, int mac_iterations, int key_type) {
1071   if (key_nid == 0) {
1072     key_nid = NID_aes_256_cbc;
1073   }
1074   if (cert_nid == 0) {
1075     cert_nid = NID_aes_256_cbc;
1076   }
1077   if (iterations == 0) {
1078     iterations = PKCS12_DEFAULT_ITER;
1079   }
1080   if (mac_iterations == 0) {
1081     mac_iterations = PKCS12_DEFAULT_ITER;
1082   }
1083   if (  // In OpenSSL, this specifies a non-standard Microsoft key usage
1084         // extension which we do not currently support.
1085       key_type != 0 ||
1086       // In OpenSSL, -1 here means to omit the MAC, which we do not
1087       // currently support. Omitting it is also invalid for a password-based
1088       // PKCS#12 file.
1089       mac_iterations < 0 ||
1090       // Don't encode empty objects.
1091       (pkey == NULL && cert == NULL && sk_X509_num(chain) == 0)) {
1092     OPENSSL_PUT_ERROR(PKCS8, PKCS8_R_UNSUPPORTED_OPTIONS);
1093     return 0;
1094   }
1095 
1096   // PKCS#12 is a very confusing recursive data format, built out of another
1097   // recursive data format. Section 5.1 of RFC 7292 describes the encoding
1098   // algorithm, but there is no clear overview. A quick summary:
1099   //
1100   // PKCS#7 defines a ContentInfo structure, which is a overgeneralized typed
1101   // combinator structure for applying cryptography. We care about two types. A
1102   // data ContentInfo contains an OCTET STRING and is a leaf node of the
1103   // combinator tree. An encrypted-data ContentInfo contains encryption
1104   // parameters (key derivation and encryption) and wraps another ContentInfo,
1105   // usually data.
1106   //
1107   // A PKCS#12 file is a PFX structure (section 4), which contains a single data
1108   // ContentInfo and a MAC over it. This root ContentInfo is the
1109   // AuthenticatedSafe and its payload is a SEQUENCE of other ContentInfos, so
1110   // that different parts of the PKCS#12 file can by differently protected.
1111   //
1112   // Each ContentInfo in the AuthenticatedSafe, after undoing all the PKCS#7
1113   // combinators, has SafeContents payload. A SafeContents is a SEQUENCE of
1114   // SafeBag. SafeBag is PKCS#12's typed structure, with subtypes such as KeyBag
1115   // and CertBag. Confusingly, there is a SafeContents bag type which itself
1116   // recursively contains more SafeBags, but we do not implement this. Bags also
1117   // can have attributes.
1118   //
1119   // The grouping of SafeBags into intermediate ContentInfos does not appear to
1120   // be significant, except that all SafeBags sharing a ContentInfo have the
1121   // same level of protection. Additionally, while keys may be encrypted by
1122   // placing a KeyBag in an encrypted-data ContentInfo, PKCS#12 also defines a
1123   // key-specific encryption container, PKCS8ShroudedKeyBag, which is used
1124   // instead.
1125 
1126   // Note that |password| may be NULL to specify no password, rather than the
1127   // empty string. They are encoded differently in PKCS#12. (One is the empty
1128   // byte array and the other is NUL-terminated UCS-2.)
1129   size_t password_len = password != NULL ? strlen(password) : 0;
1130 
1131   uint8_t key_id[EVP_MAX_MD_SIZE];
1132   unsigned key_id_len = 0;
1133   if (cert != NULL && pkey != NULL) {
1134     if (!X509_check_private_key(cert, pkey) ||
1135         // Matching OpenSSL, use the SHA-1 hash of the certificate as the local
1136         // key ID. Some PKCS#12 consumers require one to connect the private key
1137         // and certificate.
1138         !X509_digest(cert, EVP_sha1(), key_id, &key_id_len)) {
1139       return 0;
1140     }
1141   }
1142 
1143   // See https://tools.ietf.org/html/rfc7292#section-4.
1144   PKCS12 *ret = NULL;
1145   CBB cbb, pfx, auth_safe, auth_safe_wrapper, auth_safe_data, content_infos;
1146   uint8_t mac_key[EVP_MAX_MD_SIZE];
1147   if (!CBB_init(&cbb, 0) || !CBB_add_asn1(&cbb, &pfx, CBS_ASN1_SEQUENCE) ||
1148       !CBB_add_asn1_uint64(&pfx, 3) ||
1149       // auth_safe is a data ContentInfo.
1150       !CBB_add_asn1(&pfx, &auth_safe, CBS_ASN1_SEQUENCE) ||
1151       !CBB_add_asn1_element(&auth_safe, CBS_ASN1_OBJECT, kPKCS7Data,
1152                             sizeof(kPKCS7Data)) ||
1153       !CBB_add_asn1(&auth_safe, &auth_safe_wrapper,
1154                     CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 0) ||
1155       !CBB_add_asn1(&auth_safe_wrapper, &auth_safe_data,
1156                     CBS_ASN1_OCTETSTRING) ||
1157       // See https://tools.ietf.org/html/rfc7292#section-4.1. |auth_safe|'s
1158       // contains a SEQUENCE of ContentInfos.
1159       !CBB_add_asn1(&auth_safe_data, &content_infos, CBS_ASN1_SEQUENCE)) {
1160     goto err;
1161   }
1162 
1163   // If there are any certificates, place them in CertBags wrapped in a single
1164   // encrypted ContentInfo.
1165   if (cert != NULL || sk_X509_num(chain) > 0) {
1166     if (cert_nid < 0) {
1167       // Place the certificates in an unencrypted ContentInfo. This could be
1168       // more compactly-encoded by reusing the same ContentInfo as the key, but
1169       // OpenSSL does not do this. We keep them separate for consistency. (Keys,
1170       // even when encrypted, are always placed in unencrypted ContentInfos.
1171       // PKCS#12 defines bag-level encryption for keys.)
1172       CBB content_info, wrapper, data;
1173       if (!CBB_add_asn1(&content_infos, &content_info, CBS_ASN1_SEQUENCE) ||
1174           !CBB_add_asn1_element(&content_info, CBS_ASN1_OBJECT, kPKCS7Data,
1175                                 sizeof(kPKCS7Data)) ||
1176           !CBB_add_asn1(&content_info, &wrapper,
1177                         CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 0) ||
1178           !CBB_add_asn1(&wrapper, &data, CBS_ASN1_OCTETSTRING) ||
1179           !add_cert_safe_contents(&data, cert, chain, name, key_id,
1180                                   key_id_len) ||
1181           !CBB_flush(&content_infos)) {
1182         goto err;
1183       }
1184     } else {
1185       // This function differs from other OpenSSL functions in how PBES1 and
1186       // PBES2 schemes are selected. If the NID matches a cipher, treat this as
1187       // PBES2 instead. Convert to the other convention.
1188       const EVP_CIPHER *cipher = pkcs5_pbe2_nid_to_cipher(cert_nid);
1189       if (cipher != nullptr) {
1190         cert_nid = -1;
1191       }
1192       CBB plaintext_cbb;
1193       int ok =
1194           CBB_init(&plaintext_cbb, 0) &&
1195           add_cert_safe_contents(&plaintext_cbb, cert, chain, name, key_id,
1196                                  key_id_len) &&
1197           add_encrypted_data(&content_infos, cert_nid, cipher, password,
1198                              password_len, iterations, CBB_data(&plaintext_cbb),
1199                              CBB_len(&plaintext_cbb));
1200       CBB_cleanup(&plaintext_cbb);
1201       if (!ok) {
1202         goto err;
1203       }
1204     }
1205   }
1206 
1207   // If there is a key, place it in a single KeyBag or PKCS8ShroudedKeyBag
1208   // wrapped in an unencrypted ContentInfo. (One could also place it in a KeyBag
1209   // inside an encrypted ContentInfo, but OpenSSL does not do this and some
1210   // PKCS#12 consumers do not support KeyBags.)
1211   if (pkey != NULL) {
1212     CBB content_info, wrapper, data, safe_contents, bag, bag_contents;
1213     if (  // Add another data ContentInfo.
1214         !CBB_add_asn1(&content_infos, &content_info, CBS_ASN1_SEQUENCE) ||
1215         !CBB_add_asn1_element(&content_info, CBS_ASN1_OBJECT, kPKCS7Data,
1216                               sizeof(kPKCS7Data)) ||
1217         !CBB_add_asn1(&content_info, &wrapper,
1218                       CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 0) ||
1219         !CBB_add_asn1(&wrapper, &data, CBS_ASN1_OCTETSTRING) ||
1220         !CBB_add_asn1(&data, &safe_contents, CBS_ASN1_SEQUENCE) ||
1221         // Add a SafeBag containing a PKCS8ShroudedKeyBag.
1222         !CBB_add_asn1(&safe_contents, &bag, CBS_ASN1_SEQUENCE)) {
1223       goto err;
1224     }
1225     if (key_nid < 0) {
1226       if (!CBB_add_asn1_element(&bag, CBS_ASN1_OBJECT, kKeyBag,
1227                                 sizeof(kKeyBag)) ||
1228           !CBB_add_asn1(&bag, &bag_contents,
1229                         CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 0) ||
1230           !EVP_marshal_private_key(&bag_contents, pkey)) {
1231         goto err;
1232       }
1233     } else {
1234       // This function differs from other OpenSSL functions in how PBES1 and
1235       // PBES2 schemes are selected. If the NID matches a cipher, treat this as
1236       // PBES2 instead. Convert to the other convention.
1237       const EVP_CIPHER *cipher = pkcs5_pbe2_nid_to_cipher(key_nid);
1238       if (cipher != nullptr) {
1239         key_nid = -1;
1240       }
1241       if (!CBB_add_asn1_element(&bag, CBS_ASN1_OBJECT, kPKCS8ShroudedKeyBag,
1242                                 sizeof(kPKCS8ShroudedKeyBag)) ||
1243           !CBB_add_asn1(&bag, &bag_contents,
1244                         CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 0) ||
1245           !PKCS8_marshal_encrypted_private_key(
1246               &bag_contents, key_nid, cipher, password, password_len,
1247               NULL /* generate a random salt */,
1248               0 /* use default salt length */, iterations, pkey)) {
1249         goto err;
1250       }
1251     }
1252     size_t name_len = 0;
1253     if (name) {
1254       name_len = strlen(name);
1255     }
1256     if (!add_bag_attributes(&bag, name, name_len, key_id, key_id_len) ||
1257         !CBB_flush(&content_infos)) {
1258       goto err;
1259     }
1260   }
1261 
1262   {
1263     // Compute the MAC. Match OpenSSL in using SHA-1 as the hash function. The
1264     // MAC covers |auth_safe_data|.
1265     const EVP_MD *mac_md = EVP_sha1();
1266     uint8_t mac_salt[PKCS5_SALT_LEN];
1267     uint8_t mac[EVP_MAX_MD_SIZE];
1268     unsigned mac_len;
1269     if (!CBB_flush(&auth_safe_data) ||
1270         !RAND_bytes(mac_salt, sizeof(mac_salt)) ||
1271         !pkcs12_key_gen(password, password_len, mac_salt, sizeof(mac_salt),
1272                         PKCS12_MAC_ID, mac_iterations, EVP_MD_size(mac_md),
1273                         mac_key, mac_md) ||
1274         !HMAC(mac_md, mac_key, EVP_MD_size(mac_md), CBB_data(&auth_safe_data),
1275               CBB_len(&auth_safe_data), mac, &mac_len)) {
1276       goto err;
1277     }
1278 
1279     CBB mac_data, digest_info;
1280     if (!CBB_add_asn1(&pfx, &mac_data, CBS_ASN1_SEQUENCE) ||
1281         !CBB_add_asn1(&mac_data, &digest_info, CBS_ASN1_SEQUENCE) ||
1282         // OpenSSL and NSS always include a NULL parameter with the digest
1283         // algorithm. Windows does not. RFC 7292 imports DigestInfo from PKCS
1284         // #7. PKCS #7 does not actually use DigestInfo. It just describes
1285         // RSASSA-PKCS1-v1_5 signing as encoding a DigestInfo and then
1286         // "encrypting" it with the private key. In that context, NULL should be
1287         // included. Confusingly, there is also a digestAlgorithm field in
1288         // SignerInfo. There, RFC 5754 says to omit the NULL. But that field
1289         // does not use DigestInfo per se.
1290         //
1291         // We match OpenSSL, NSS, and RSASSA-PKCS1-v1_5 in including the NULL.
1292         !EVP_marshal_digest_algorithm(&digest_info, mac_md) ||
1293         !CBB_add_asn1_octet_string(&digest_info, mac, mac_len) ||
1294         !CBB_add_asn1_octet_string(&mac_data, mac_salt, sizeof(mac_salt)) ||
1295         // The iteration count has a DEFAULT of 1, but RFC 7292 says "The
1296         // default is for historical reasons and its use is deprecated." Thus we
1297         // explicitly encode the iteration count, though it is not valid DER.
1298         !CBB_add_asn1_uint64(&mac_data, mac_iterations)) {
1299       goto err;
1300     }
1301 
1302     ret = reinterpret_cast<PKCS12 *>(OPENSSL_malloc(sizeof(PKCS12)));
1303     if (ret == NULL || !CBB_finish(&cbb, &ret->ber_bytes, &ret->ber_len)) {
1304       OPENSSL_free(ret);
1305       ret = NULL;
1306       goto err;
1307     }
1308   }
1309 
1310 err:
1311   OPENSSL_cleanse(mac_key, sizeof(mac_key));
1312   CBB_cleanup(&cbb);
1313   return ret;
1314 }
1315 
PKCS12_free(PKCS12 * p12)1316 void PKCS12_free(PKCS12 *p12) {
1317   if (p12 == NULL) {
1318     return;
1319   }
1320   OPENSSL_free(p12->ber_bytes);
1321   OPENSSL_free(p12);
1322 }
1323