1/* Copyright (c) 2014, Google Inc.
2 *
3 * Permission to use, copy, modify, and/or distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
6 *
7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14
15#include <openssl/pkcs7.h>
16
17#include <openssl/bytestring.h>
18#include <openssl/err.h>
19#include <openssl/mem.h>
20#include <openssl/pool.h>
21#include <openssl/stack.h>
22
23#include "internal.h"
24#include "../bytestring/internal.h"
25
26
27// 1.2.840.113549.1.7.1
28static const uint8_t kPKCS7Data[] = {0x2a, 0x86, 0x48, 0x86, 0xf7,
29 0x0d, 0x01, 0x07, 0x01};
30
31// 1.2.840.113549.1.7.2
32static const uint8_t kPKCS7SignedData[] = {0x2a, 0x86, 0x48, 0x86, 0xf7,
33 0x0d, 0x01, 0x07, 0x02};
34
35// pkcs7_parse_header reads the non-certificate/non-CRL prefix of a PKCS#7
36// SignedData blob from |cbs| and sets |*out| to point to the rest of the
37// input. If the input is in BER format, then |*der_bytes| will be set to a
38// pointer that needs to be freed by the caller once they have finished
39// processing |*out| (which will be pointing into |*der_bytes|).
40//
41// It returns one on success or zero on error. On error, |*der_bytes| is
42// NULL.
43int pkcs7_parse_header(uint8_t **der_bytes, CBS *out, CBS *cbs) {
44 CBS in, content_info, content_type, wrapped_signed_data, signed_data;
45 uint64_t version;
46
47 // The input may be in BER format.
48 *der_bytes = NULL;
49 if (!CBS_asn1_ber_to_der(cbs, &in, der_bytes) ||
50 // See https://tools.ietf.org/html/rfc2315#section-7
51 !CBS_get_asn1(&in, &content_info, CBS_ASN1_SEQUENCE) ||
52 !CBS_get_asn1(&content_info, &content_type, CBS_ASN1_OBJECT)) {
53 goto err;
54 }
55
56 if (!CBS_mem_equal(&content_type, kPKCS7SignedData,
57 sizeof(kPKCS7SignedData))) {
58 OPENSSL_PUT_ERROR(PKCS7, PKCS7_R_NOT_PKCS7_SIGNED_DATA);
59 goto err;
60 }
61
62 // See https://tools.ietf.org/html/rfc2315#section-9.1
63 if (!CBS_get_asn1(&content_info, &wrapped_signed_data,
64 CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0) ||
65 !CBS_get_asn1(&wrapped_signed_data, &signed_data, CBS_ASN1_SEQUENCE) ||
66 !CBS_get_asn1_uint64(&signed_data, &version) ||
67 !CBS_get_asn1(&signed_data, NULL /* digests */, CBS_ASN1_SET) ||
68 !CBS_get_asn1(&signed_data, NULL /* content */, CBS_ASN1_SEQUENCE)) {
69 goto err;
70 }
71
72 if (version < 1) {
73 OPENSSL_PUT_ERROR(PKCS7, PKCS7_R_BAD_PKCS7_VERSION);
74 goto err;
75 }
76
77 CBS_init(out, CBS_data(&signed_data), CBS_len(&signed_data));
78 return 1;
79
80err:
81 OPENSSL_free(*der_bytes);
82 *der_bytes = NULL;
83 return 0;
84}
85
86int PKCS7_get_raw_certificates(STACK_OF(CRYPTO_BUFFER) *out_certs, CBS *cbs,
87 CRYPTO_BUFFER_POOL *pool) {
88 CBS signed_data, certificates;
89 uint8_t *der_bytes = NULL;
90 int ret = 0, has_certificates;
91 const size_t initial_certs_len = sk_CRYPTO_BUFFER_num(out_certs);
92
93 // See https://tools.ietf.org/html/rfc2315#section-9.1
94 if (!pkcs7_parse_header(&der_bytes, &signed_data, cbs) ||
95 !CBS_get_optional_asn1(
96 &signed_data, &certificates, &has_certificates,
97 CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0)) {
98 goto err;
99 }
100
101 if (!has_certificates) {
102 CBS_init(&certificates, NULL, 0);
103 }
104
105 while (CBS_len(&certificates) > 0) {
106 CBS cert;
107 if (!CBS_get_asn1_element(&certificates, &cert, CBS_ASN1_SEQUENCE)) {
108 goto err;
109 }
110
111 CRYPTO_BUFFER *buf = CRYPTO_BUFFER_new_from_CBS(&cert, pool);
112 if (buf == NULL ||
113 !sk_CRYPTO_BUFFER_push(out_certs, buf)) {
114 CRYPTO_BUFFER_free(buf);
115 goto err;
116 }
117 }
118
119 ret = 1;
120
121err:
122 OPENSSL_free(der_bytes);
123
124 if (!ret) {
125 while (sk_CRYPTO_BUFFER_num(out_certs) != initial_certs_len) {
126 CRYPTO_BUFFER *buf = sk_CRYPTO_BUFFER_pop(out_certs);
127 CRYPTO_BUFFER_free(buf);
128 }
129 }
130
131 return ret;
132}
133
134int pkcs7_bundle(CBB *out, int (*cb)(CBB *out, const void *arg),
135 const void *arg) {
136 CBB outer_seq, oid, wrapped_seq, seq, version_bytes, digest_algos_set,
137 content_info, signer_infos;
138
139 // See https://tools.ietf.org/html/rfc2315#section-7
140 if (!CBB_add_asn1(out, &outer_seq, CBS_ASN1_SEQUENCE) ||
141 !CBB_add_asn1(&outer_seq, &oid, CBS_ASN1_OBJECT) ||
142 !CBB_add_bytes(&oid, kPKCS7SignedData, sizeof(kPKCS7SignedData)) ||
143 !CBB_add_asn1(&outer_seq, &wrapped_seq,
144 CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0) ||
145 // See https://tools.ietf.org/html/rfc2315#section-9.1
146 !CBB_add_asn1(&wrapped_seq, &seq, CBS_ASN1_SEQUENCE) ||
147 !CBB_add_asn1(&seq, &version_bytes, CBS_ASN1_INTEGER) ||
148 !CBB_add_u8(&version_bytes, 1) ||
149 !CBB_add_asn1(&seq, &digest_algos_set, CBS_ASN1_SET) ||
150 !CBB_add_asn1(&seq, &content_info, CBS_ASN1_SEQUENCE) ||
151 !CBB_add_asn1(&content_info, &oid, CBS_ASN1_OBJECT) ||
152 !CBB_add_bytes(&oid, kPKCS7Data, sizeof(kPKCS7Data)) ||
153 !cb(&seq, arg) ||
154 !CBB_add_asn1(&seq, &signer_infos, CBS_ASN1_SET)) {
155 return 0;
156 }
157
158 return CBB_flush(out);
159}
160