1 /*
2 * Copyright 2008-2023 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 "crypto/asn1.h"
19 #include "cms_local.h"
20
21 /* CMS EncryptedData Utilities */
22
23 /* Return BIO based on EncryptedContentInfo and key */
24
ossl_cms_EncryptedContent_init_bio(CMS_EncryptedContentInfo * ec,const CMS_CTX * cms_ctx)25 BIO *ossl_cms_EncryptedContent_init_bio(CMS_EncryptedContentInfo *ec,
26 const CMS_CTX *cms_ctx)
27 {
28 BIO *b;
29 EVP_CIPHER_CTX *ctx;
30 EVP_CIPHER *fetched_ciph = NULL;
31 const EVP_CIPHER *cipher = NULL;
32 X509_ALGOR *calg = ec->contentEncryptionAlgorithm;
33 evp_cipher_aead_asn1_params aparams;
34 unsigned char iv[EVP_MAX_IV_LENGTH], *piv = NULL;
35 unsigned char *tkey = NULL;
36 int len;
37 int ivlen = 0;
38 size_t tkeylen = 0;
39 int ok = 0;
40 int enc, keep_key = 0;
41 OSSL_LIB_CTX *libctx = ossl_cms_ctx_get0_libctx(cms_ctx);
42 const char *propq = ossl_cms_ctx_get0_propq(cms_ctx);
43
44 enc = ec->cipher ? 1 : 0;
45
46 b = BIO_new(BIO_f_cipher());
47 if (b == NULL) {
48 ERR_raise(ERR_LIB_CMS, ERR_R_MALLOC_FAILURE);
49 return NULL;
50 }
51
52 BIO_get_cipher_ctx(b, &ctx);
53
54 (void)ERR_set_mark();
55 if (enc) {
56 cipher = ec->cipher;
57 /*
58 * If not keeping key set cipher to NULL so subsequent calls decrypt.
59 */
60 if (ec->key != NULL)
61 ec->cipher = NULL;
62 } else {
63 cipher = EVP_get_cipherbyobj(calg->algorithm);
64 }
65 if (cipher != NULL) {
66 fetched_ciph = EVP_CIPHER_fetch(libctx, EVP_CIPHER_get0_name(cipher),
67 propq);
68 if (fetched_ciph != NULL)
69 cipher = fetched_ciph;
70 }
71 if (cipher == NULL) {
72 (void)ERR_clear_last_mark();
73 ERR_raise(ERR_LIB_CMS, CMS_R_UNKNOWN_CIPHER);
74 goto err;
75 }
76 (void)ERR_pop_to_mark();
77
78 if (EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, enc) <= 0) {
79 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_INITIALISATION_ERROR);
80 goto err;
81 }
82
83 if (enc) {
84 calg->algorithm = OBJ_nid2obj(EVP_CIPHER_CTX_get_type(ctx));
85 if (calg->algorithm == NULL || calg->algorithm->nid == NID_undef) {
86 ERR_raise(ERR_LIB_CMS, CMS_R_UNSUPPORTED_CONTENT_ENCRYPTION_ALGORITHM);
87 goto err;
88 }
89 /* Generate a random IV if we need one */
90 ivlen = EVP_CIPHER_CTX_get_iv_length(ctx);
91 if (ivlen < 0) {
92 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
93 goto err;
94 }
95
96 if (ivlen > 0) {
97 if (RAND_bytes_ex(libctx, iv, ivlen, 0) <= 0)
98 goto err;
99 piv = iv;
100 }
101 } else {
102 if (evp_cipher_asn1_to_param_ex(ctx, calg->parameter, &aparams) <= 0) {
103 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
104 goto err;
105 }
106 if ((EVP_CIPHER_get_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER)) {
107 piv = aparams.iv;
108 if (ec->taglen > 0
109 && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG,
110 ec->taglen, ec->tag) <= 0) {
111 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_AEAD_SET_TAG_ERROR);
112 goto err;
113 }
114 }
115 }
116 len = EVP_CIPHER_CTX_get_key_length(ctx);
117 if (len <= 0)
118 goto err;
119 tkeylen = (size_t)len;
120
121 /* Generate random session key */
122 if (!enc || !ec->key) {
123 tkey = OPENSSL_malloc(tkeylen);
124 if (tkey == NULL) {
125 ERR_raise(ERR_LIB_CMS, ERR_R_MALLOC_FAILURE);
126 goto err;
127 }
128 if (EVP_CIPHER_CTX_rand_key(ctx, tkey) <= 0)
129 goto err;
130 }
131
132 if (!ec->key) {
133 ec->key = tkey;
134 ec->keylen = tkeylen;
135 tkey = NULL;
136 if (enc)
137 keep_key = 1;
138 else
139 ERR_clear_error();
140
141 }
142
143 if (ec->keylen != tkeylen) {
144 /* If necessary set key length */
145 if (EVP_CIPHER_CTX_set_key_length(ctx, ec->keylen) <= 0) {
146 /*
147 * Only reveal failure if debugging so we don't leak information
148 * which may be useful in MMA.
149 */
150 if (enc || ec->debug) {
151 ERR_raise(ERR_LIB_CMS, CMS_R_INVALID_KEY_LENGTH);
152 goto err;
153 } else {
154 /* Use random key */
155 OPENSSL_clear_free(ec->key, ec->keylen);
156 ec->key = tkey;
157 ec->keylen = tkeylen;
158 tkey = NULL;
159 ERR_clear_error();
160 }
161 }
162 }
163
164 if (EVP_CipherInit_ex(ctx, NULL, NULL, ec->key, piv, enc) <= 0) {
165 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_INITIALISATION_ERROR);
166 goto err;
167 }
168 if (enc) {
169 calg->parameter = ASN1_TYPE_new();
170 if (calg->parameter == NULL) {
171 ERR_raise(ERR_LIB_CMS, ERR_R_MALLOC_FAILURE);
172 goto err;
173 }
174 if ((EVP_CIPHER_get_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER)) {
175 memcpy(aparams.iv, piv, ivlen);
176 aparams.iv_len = ivlen;
177 aparams.tag_len = EVP_CIPHER_CTX_get_tag_length(ctx);
178 if (aparams.tag_len <= 0)
179 goto err;
180 }
181
182 if (evp_cipher_param_to_asn1_ex(ctx, calg->parameter, &aparams) <= 0) {
183 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
184 goto err;
185 }
186 /* If parameter type not set omit parameter */
187 if (calg->parameter->type == V_ASN1_UNDEF) {
188 ASN1_TYPE_free(calg->parameter);
189 calg->parameter = NULL;
190 }
191 }
192 ok = 1;
193
194 err:
195 EVP_CIPHER_free(fetched_ciph);
196 if (!keep_key || !ok) {
197 OPENSSL_clear_free(ec->key, ec->keylen);
198 ec->key = NULL;
199 }
200 OPENSSL_clear_free(tkey, tkeylen);
201 if (ok)
202 return b;
203 BIO_free(b);
204 return NULL;
205 }
206
ossl_cms_EncryptedContent_init(CMS_EncryptedContentInfo * ec,const EVP_CIPHER * cipher,const unsigned char * key,size_t keylen,const CMS_CTX * cms_ctx)207 int ossl_cms_EncryptedContent_init(CMS_EncryptedContentInfo *ec,
208 const EVP_CIPHER *cipher,
209 const unsigned char *key, size_t keylen,
210 const CMS_CTX *cms_ctx)
211 {
212 ec->cipher = cipher;
213 if (key) {
214 if ((ec->key = OPENSSL_malloc(keylen)) == NULL) {
215 ERR_raise(ERR_LIB_CMS, ERR_R_MALLOC_FAILURE);
216 return 0;
217 }
218 memcpy(ec->key, key, keylen);
219 }
220 ec->keylen = keylen;
221 if (cipher != NULL)
222 ec->contentType = OBJ_nid2obj(NID_pkcs7_data);
223 return 1;
224 }
225
CMS_EncryptedData_set1_key(CMS_ContentInfo * cms,const EVP_CIPHER * ciph,const unsigned char * key,size_t keylen)226 int CMS_EncryptedData_set1_key(CMS_ContentInfo *cms, const EVP_CIPHER *ciph,
227 const unsigned char *key, size_t keylen)
228 {
229 CMS_EncryptedContentInfo *ec;
230
231 if (!key || !keylen) {
232 ERR_raise(ERR_LIB_CMS, CMS_R_NO_KEY);
233 return 0;
234 }
235 if (ciph) {
236 cms->d.encryptedData = M_ASN1_new_of(CMS_EncryptedData);
237 if (!cms->d.encryptedData) {
238 ERR_raise(ERR_LIB_CMS, ERR_R_MALLOC_FAILURE);
239 return 0;
240 }
241 cms->contentType = OBJ_nid2obj(NID_pkcs7_encrypted);
242 cms->d.encryptedData->version = 0;
243 } else if (OBJ_obj2nid(cms->contentType) != NID_pkcs7_encrypted) {
244 ERR_raise(ERR_LIB_CMS, CMS_R_NOT_ENCRYPTED_DATA);
245 return 0;
246 }
247 ec = cms->d.encryptedData->encryptedContentInfo;
248 return ossl_cms_EncryptedContent_init(ec, ciph, key, keylen,
249 ossl_cms_get0_cmsctx(cms));
250 }
251
ossl_cms_EncryptedData_init_bio(const CMS_ContentInfo * cms)252 BIO *ossl_cms_EncryptedData_init_bio(const CMS_ContentInfo *cms)
253 {
254 CMS_EncryptedData *enc = cms->d.encryptedData;
255 if (enc->encryptedContentInfo->cipher && enc->unprotectedAttrs)
256 enc->version = 2;
257 return ossl_cms_EncryptedContent_init_bio(enc->encryptedContentInfo,
258 ossl_cms_get0_cmsctx(cms));
259 }
260