1/*
2 * Copyright 2008-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (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#include "internal/cryptlib.h"
11#include <openssl/asn1t.h>
12#include <openssl/pem.h>
13#include <openssl/x509v3.h>
14#include <openssl/err.h>
15#include <openssl/cms.h>
16#include <openssl/rand.h>
17#include "cms_local.h"
18
19/* CMS EncryptedData Utilities */
20
21/* Return BIO based on EncryptedContentInfo and key */
22
23BIO *cms_EncryptedContent_init_bio(CMS_EncryptedContentInfo *ec)
24{
25 BIO *b;
26 EVP_CIPHER_CTX *ctx;
27 const EVP_CIPHER *ciph;
28 X509_ALGOR *calg = ec->contentEncryptionAlgorithm;
29 unsigned char iv[EVP_MAX_IV_LENGTH], *piv = NULL;
30 unsigned char *tkey = NULL;
31 size_t tkeylen = 0;
32
33 int ok = 0;
34
35 int enc, keep_key = 0;
36
37 enc = ec->cipher ? 1 : 0;
38
39 b = BIO_new(BIO_f_cipher());
40 if (b == NULL) {
41 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE);
42 return NULL;
43 }
44
45 BIO_get_cipher_ctx(b, &ctx);
46
47 if (enc) {
48 ciph = ec->cipher;
49 /*
50 * If not keeping key set cipher to NULL so subsequent calls decrypt.
51 */
52 if (ec->key)
53 ec->cipher = NULL;
54 } else {
55 ciph = EVP_get_cipherbyobj(calg->algorithm);
56
57 if (!ciph) {
58 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, CMS_R_UNKNOWN_CIPHER);
59 goto err;
60 }
61 }
62
63 if (EVP_CipherInit_ex(ctx, ciph, NULL, NULL, NULL, enc) <= 0) {
64 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
65 CMS_R_CIPHER_INITIALISATION_ERROR);
66 goto err;
67 }
68
69 if (enc) {
70 int ivlen;
71 calg->algorithm = OBJ_nid2obj(EVP_CIPHER_CTX_type(ctx));
72 /* Generate a random IV if we need one */
73 ivlen = EVP_CIPHER_CTX_iv_length(ctx);
74 if (ivlen > 0) {
75 if (RAND_bytes(iv, ivlen) <= 0)
76 goto err;
77 piv = iv;
78 }
79 } else if (EVP_CIPHER_asn1_to_param(ctx, calg->parameter) <= 0) {
80 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
81 CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
82 goto err;
83 }
84 tkeylen = EVP_CIPHER_CTX_key_length(ctx);
85 /* Generate random session key */
86 if (!enc || !ec->key) {
87 tkey = OPENSSL_malloc(tkeylen);
88 if (tkey == NULL) {
89 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE);
90 goto err;
91 }
92 if (EVP_CIPHER_CTX_rand_key(ctx, tkey) <= 0)
93 goto err;
94 }
95
96 if (!ec->key) {
97 ec->key = tkey;
98 ec->keylen = tkeylen;
99 tkey = NULL;
100 if (enc)
101 keep_key = 1;
102 else
103 ERR_clear_error();
104
105 }
106
107 if (ec->keylen != tkeylen) {
108 /* If necessary set key length */
109 if (EVP_CIPHER_CTX_set_key_length(ctx, ec->keylen) <= 0) {
110 /*
111 * Only reveal failure if debugging so we don't leak information
112 * which may be useful in MMA.
113 */
114 if (enc || ec->debug) {
115 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
116 CMS_R_INVALID_KEY_LENGTH);
117 goto err;
118 } else {
119 /* Use random key */
120 OPENSSL_clear_free(ec->key, ec->keylen);
121 ec->key = tkey;
122 ec->keylen = tkeylen;
123 tkey = NULL;
124 ERR_clear_error();
125 }
126 }
127 }
128
129 if (EVP_CipherInit_ex(ctx, NULL, NULL, ec->key, piv, enc) <= 0) {
130 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
131 CMS_R_CIPHER_INITIALISATION_ERROR);
132 goto err;
133 }
134 if (enc) {
135 calg->parameter = ASN1_TYPE_new();
136 if (calg->parameter == NULL) {
137 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE);
138 goto err;
139 }
140 if (EVP_CIPHER_param_to_asn1(ctx, calg->parameter) <= 0) {
141 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
142 CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
143 goto err;
144 }
145 /* If parameter type not set omit parameter */
146 if (calg->parameter->type == V_ASN1_UNDEF) {
147 ASN1_TYPE_free(calg->parameter);
148 calg->parameter = NULL;
149 }
150 }
151 ok = 1;
152
153 err:
154 if (!keep_key || !ok) {
155 OPENSSL_clear_free(ec->key, ec->keylen);
156 ec->key = NULL;
157 }
158 OPENSSL_clear_free(tkey, tkeylen);
159 if (ok)
160 return b;
161 BIO_free(b);
162 return NULL;
163}
164
165int cms_EncryptedContent_init(CMS_EncryptedContentInfo *ec,
166 const EVP_CIPHER *cipher,
167 const unsigned char *key, size_t keylen)
168{
169 ec->cipher = cipher;
170 if (key) {
171 if ((ec->key = OPENSSL_malloc(keylen)) == NULL) {
172 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT, ERR_R_MALLOC_FAILURE);
173 return 0;
174 }
175 memcpy(ec->key, key, keylen);
176 }
177 ec->keylen = keylen;
178 if (cipher)
179 ec->contentType = OBJ_nid2obj(NID_pkcs7_data);
180 return 1;
181}
182
183int CMS_EncryptedData_set1_key(CMS_ContentInfo *cms, const EVP_CIPHER *ciph,
184 const unsigned char *key, size_t keylen)
185{
186 CMS_EncryptedContentInfo *ec;
187 if (!key || !keylen) {
188 CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, CMS_R_NO_KEY);
189 return 0;
190 }
191 if (ciph) {
192 cms->d.encryptedData = M_ASN1_new_of(CMS_EncryptedData);
193 if (!cms->d.encryptedData) {
194 CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, ERR_R_MALLOC_FAILURE);
195 return 0;
196 }
197 cms->contentType = OBJ_nid2obj(NID_pkcs7_encrypted);
198 cms->d.encryptedData->version = 0;
199 } else if (OBJ_obj2nid(cms->contentType) != NID_pkcs7_encrypted) {
200 CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, CMS_R_NOT_ENCRYPTED_DATA);
201 return 0;
202 }
203 ec = cms->d.encryptedData->encryptedContentInfo;
204 return cms_EncryptedContent_init(ec, ciph, key, keylen);
205}
206
207BIO *cms_EncryptedData_init_bio(const CMS_ContentInfo *cms)
208{
209 CMS_EncryptedData *enc = cms->d.encryptedData;
210 if (enc->encryptedContentInfo->cipher && enc->unprotectedAttrs)
211 enc->version = 2;
212 return cms_EncryptedContent_init_bio(enc->encryptedContentInfo);
213}
214