1 /*
2 * Copyright 2008-2022 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 "crypto/evp.h"
18 #include "cms_local.h"
19
20 /* CMS EncryptedData Utilities */
21
22 /* Return BIO based on EncryptedContentInfo and key */
23
ossl_cms_EncryptedContent_init_bio(CMS_EncryptedContentInfo * ec,const CMS_CTX * cms_ctx)24 BIO *ossl_cms_EncryptedContent_init_bio(CMS_EncryptedContentInfo *ec,
25 const CMS_CTX *cms_ctx)
26 {
27 BIO *b;
28 EVP_CIPHER_CTX *ctx;
29 EVP_CIPHER *fetched_ciph = NULL;
30 const EVP_CIPHER *cipher = NULL;
31 X509_ALGOR *calg = ec->contentEncryptionAlgorithm;
32 evp_cipher_aead_asn1_params aparams;
33 unsigned char iv[EVP_MAX_IV_LENGTH], *piv = NULL;
34 unsigned char *tkey = NULL;
35 int len;
36 int ivlen = 0;
37 size_t tkeylen = 0;
38 int ok = 0;
39 int enc, keep_key = 0;
40 OSSL_LIB_CTX *libctx = ossl_cms_ctx_get0_libctx(cms_ctx);
41 const char *propq = ossl_cms_ctx_get0_propq(cms_ctx);
42
43 enc = ec->cipher ? 1 : 0;
44
45 b = BIO_new(BIO_f_cipher());
46 if (b == NULL) {
47 ERR_raise(ERR_LIB_CMS, ERR_R_MALLOC_FAILURE);
48 return NULL;
49 }
50
51 BIO_get_cipher_ctx(b, &ctx);
52
53 (void)ERR_set_mark();
54 if (enc) {
55 cipher = ec->cipher;
56 /*
57 * If not keeping key set cipher to NULL so subsequent calls decrypt.
58 */
59 if (ec->key != NULL)
60 ec->cipher = NULL;
61 } else {
62 cipher = EVP_get_cipherbyobj(calg->algorithm);
63 }
64 if (cipher != NULL) {
65 fetched_ciph = EVP_CIPHER_fetch(libctx, EVP_CIPHER_get0_name(cipher),
66 propq);
67 if (fetched_ciph != NULL)
68 cipher = fetched_ciph;
69 }
70 if (cipher == NULL) {
71 (void)ERR_clear_last_mark();
72 ERR_raise(ERR_LIB_CMS, CMS_R_UNKNOWN_CIPHER);
73 goto err;
74 }
75 (void)ERR_pop_to_mark();
76
77 if (EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, enc) <= 0) {
78 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_INITIALISATION_ERROR);
79 goto err;
80 }
81
82 if (enc) {
83 calg->algorithm = OBJ_nid2obj(EVP_CIPHER_CTX_get_type(ctx));
84 if (calg->algorithm == NULL) {
85 ERR_raise(ERR_LIB_CMS, CMS_R_UNSUPPORTED_CONTENT_ENCRYPTION_ALGORITHM);
86 goto err;
87 }
88 /* Generate a random IV if we need one */
89 ivlen = EVP_CIPHER_CTX_get_iv_length(ctx);
90 if (ivlen < 0) {
91 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
92 goto err;
93 }
94
95 if (ivlen > 0) {
96 if (RAND_bytes_ex(libctx, iv, ivlen, 0) <= 0)
97 goto err;
98 piv = iv;
99 }
100 } else {
101 if (evp_cipher_asn1_to_param_ex(ctx, calg->parameter, &aparams) <= 0) {
102 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
103 goto err;
104 }
105 if ((EVP_CIPHER_get_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER)) {
106 piv = aparams.iv;
107 if (ec->taglen > 0
108 && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG,
109 ec->taglen, ec->tag) <= 0) {
110 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_AEAD_SET_TAG_ERROR);
111 goto err;
112 }
113 }
114 }
115 len = EVP_CIPHER_CTX_get_key_length(ctx);
116 if (len <= 0)
117 goto err;
118 tkeylen = (size_t)len;
119
120 /* Generate random session key */
121 if (!enc || !ec->key) {
122 tkey = OPENSSL_malloc(tkeylen);
123 if (tkey == NULL) {
124 ERR_raise(ERR_LIB_CMS, ERR_R_MALLOC_FAILURE);
125 goto err;
126 }
127 if (EVP_CIPHER_CTX_rand_key(ctx, tkey) <= 0)
128 goto err;
129 }
130
131 if (!ec->key) {
132 ec->key = tkey;
133 ec->keylen = tkeylen;
134 tkey = NULL;
135 if (enc)
136 keep_key = 1;
137 else
138 ERR_clear_error();
139
140 }
141
142 if (ec->keylen != tkeylen) {
143 /* If necessary set key length */
144 if (EVP_CIPHER_CTX_set_key_length(ctx, ec->keylen) <= 0) {
145 /*
146 * Only reveal failure if debugging so we don't leak information
147 * which may be useful in MMA.
148 */
149 if (enc || ec->debug) {
150 ERR_raise(ERR_LIB_CMS, CMS_R_INVALID_KEY_LENGTH);
151 goto err;
152 } else {
153 /* Use random key */
154 OPENSSL_clear_free(ec->key, ec->keylen);
155 ec->key = tkey;
156 ec->keylen = tkeylen;
157 tkey = NULL;
158 ERR_clear_error();
159 }
160 }
161 }
162
163 if (EVP_CipherInit_ex(ctx, NULL, NULL, ec->key, piv, enc) <= 0) {
164 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_INITIALISATION_ERROR);
165 goto err;
166 }
167 if (enc) {
168 calg->parameter = ASN1_TYPE_new();
169 if (calg->parameter == NULL) {
170 ERR_raise(ERR_LIB_CMS, ERR_R_MALLOC_FAILURE);
171 goto err;
172 }
173 if ((EVP_CIPHER_get_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER)) {
174 memcpy(aparams.iv, piv, ivlen);
175 aparams.iv_len = ivlen;
176 aparams.tag_len = EVP_CIPHER_CTX_get_tag_length(ctx);
177 if (aparams.tag_len <= 0)
178 goto err;
179 }
180
181 if (evp_cipher_param_to_asn1_ex(ctx, calg->parameter, &aparams) <= 0) {
182 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
183 goto err;
184 }
185 /* If parameter type not set omit parameter */
186 if (calg->parameter->type == V_ASN1_UNDEF) {
187 ASN1_TYPE_free(calg->parameter);
188 calg->parameter = NULL;
189 }
190 }
191 ok = 1;
192
193 err:
194 EVP_CIPHER_free(fetched_ciph);
195 if (!keep_key || !ok) {
196 OPENSSL_clear_free(ec->key, ec->keylen);
197 ec->key = NULL;
198 }
199 OPENSSL_clear_free(tkey, tkeylen);
200 if (ok)
201 return b;
202 BIO_free(b);
203 return NULL;
204 }
205
ossl_cms_EncryptedContent_init(CMS_EncryptedContentInfo * ec,const EVP_CIPHER * cipher,const unsigned char * key,size_t keylen,const CMS_CTX * cms_ctx)206 int ossl_cms_EncryptedContent_init(CMS_EncryptedContentInfo *ec,
207 const EVP_CIPHER *cipher,
208 const unsigned char *key, size_t keylen,
209 const CMS_CTX *cms_ctx)
210 {
211 ec->cipher = cipher;
212 if (key) {
213 if ((ec->key = OPENSSL_malloc(keylen)) == NULL) {
214 ERR_raise(ERR_LIB_CMS, ERR_R_MALLOC_FAILURE);
215 return 0;
216 }
217 memcpy(ec->key, key, keylen);
218 }
219 ec->keylen = keylen;
220 if (cipher != NULL)
221 ec->contentType = OBJ_nid2obj(NID_pkcs7_data);
222 return 1;
223 }
224
CMS_EncryptedData_set1_key(CMS_ContentInfo * cms,const EVP_CIPHER * ciph,const unsigned char * key,size_t keylen)225 int CMS_EncryptedData_set1_key(CMS_ContentInfo *cms, const EVP_CIPHER *ciph,
226 const unsigned char *key, size_t keylen)
227 {
228 CMS_EncryptedContentInfo *ec;
229
230 if (!key || !keylen) {
231 ERR_raise(ERR_LIB_CMS, CMS_R_NO_KEY);
232 return 0;
233 }
234 if (ciph) {
235 cms->d.encryptedData = M_ASN1_new_of(CMS_EncryptedData);
236 if (!cms->d.encryptedData) {
237 ERR_raise(ERR_LIB_CMS, ERR_R_MALLOC_FAILURE);
238 return 0;
239 }
240 cms->contentType = OBJ_nid2obj(NID_pkcs7_encrypted);
241 cms->d.encryptedData->version = 0;
242 } else if (OBJ_obj2nid(cms->contentType) != NID_pkcs7_encrypted) {
243 ERR_raise(ERR_LIB_CMS, CMS_R_NOT_ENCRYPTED_DATA);
244 return 0;
245 }
246 ec = cms->d.encryptedData->encryptedContentInfo;
247 return ossl_cms_EncryptedContent_init(ec, ciph, key, keylen,
248 ossl_cms_get0_cmsctx(cms));
249 }
250
ossl_cms_EncryptedData_init_bio(const CMS_ContentInfo * cms)251 BIO *ossl_cms_EncryptedData_init_bio(const CMS_ContentInfo *cms)
252 {
253 CMS_EncryptedData *enc = cms->d.encryptedData;
254 if (enc->encryptedContentInfo->cipher && enc->unprotectedAttrs)
255 enc->version = 2;
256 return ossl_cms_EncryptedContent_init_bio(enc->encryptedContentInfo,
257 ossl_cms_get0_cmsctx(cms));
258 }
259