1 /* crypto/cms/cms_enc.c */ 2 /* Written by Dr Stephen N Henson (steve (at) openssl.org) for the OpenSSL 3 * project. 4 */ 5 /* ==================================================================== 6 * Copyright (c) 2008 The OpenSSL Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * licensing (at) OpenSSL.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 */ 53 54 #include "cryptlib.h" 55 #include <openssl/asn1t.h> 56 #include <openssl/pem.h> 57 #include <openssl/x509v3.h> 58 #include <openssl/err.h> 59 #include <openssl/cms.h> 60 #include <openssl/rand.h> 61 #include "cms_lcl.h" 62 63 /* CMS EncryptedData Utilities */ 64 65 DECLARE_ASN1_ITEM(CMS_EncryptedData) 66 67 /* Return BIO based on EncryptedContentInfo and key */ 68 69 BIO *cms_EncryptedContent_init_bio(CMS_EncryptedContentInfo *ec) 70 { 71 BIO *b; 72 EVP_CIPHER_CTX *ctx; 73 const EVP_CIPHER *ciph; 74 X509_ALGOR *calg = ec->contentEncryptionAlgorithm; 75 unsigned char iv[EVP_MAX_IV_LENGTH], *piv = NULL; 76 unsigned char *tkey = NULL; 77 size_t tkeylen = 0; 78 79 int ok = 0; 80 81 int enc, keep_key = 0; 82 83 enc = ec->cipher ? 1 : 0; 84 85 b = BIO_new(BIO_f_cipher()); 86 if (!b) 87 { 88 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, 89 ERR_R_MALLOC_FAILURE); 90 return NULL; 91 } 92 93 BIO_get_cipher_ctx(b, &ctx); 94 95 if (enc) 96 { 97 ciph = ec->cipher; 98 /* If not keeping key set cipher to NULL so subsequent calls 99 * decrypt. 100 */ 101 if (ec->key) 102 ec->cipher = NULL; 103 } 104 else 105 { 106 ciph = EVP_get_cipherbyobj(calg->algorithm); 107 108 if (!ciph) 109 { 110 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, 111 CMS_R_UNKNOWN_CIPHER); 112 goto err; 113 } 114 } 115 116 if (EVP_CipherInit_ex(ctx, ciph, NULL, NULL, NULL, enc) <= 0) 117 { 118 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, 119 CMS_R_CIPHER_INITIALISATION_ERROR); 120 goto err; 121 } 122 123 if (enc) 124 { 125 int ivlen; 126 calg->algorithm = OBJ_nid2obj(EVP_CIPHER_CTX_type(ctx)); 127 /* Generate a random IV if we need one */ 128 ivlen = EVP_CIPHER_CTX_iv_length(ctx); 129 if (ivlen > 0) 130 { 131 if (RAND_pseudo_bytes(iv, ivlen) <= 0) 132 goto err; 133 piv = iv; 134 } 135 } 136 else if (EVP_CIPHER_asn1_to_param(ctx, calg->parameter) <= 0) 137 { 138 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, 139 CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR); 140 goto err; 141 } 142 tkeylen = EVP_CIPHER_CTX_key_length(ctx); 143 /* Generate random session key */ 144 if (!enc || !ec->key) 145 { 146 tkey = OPENSSL_malloc(tkeylen); 147 if (!tkey) 148 { 149 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, 150 ERR_R_MALLOC_FAILURE); 151 goto err; 152 } 153 if (EVP_CIPHER_CTX_rand_key(ctx, tkey) <= 0) 154 goto err; 155 } 156 157 if (!ec->key) 158 { 159 ec->key = tkey; 160 ec->keylen = tkeylen; 161 tkey = NULL; 162 if (enc) 163 keep_key = 1; 164 else 165 ERR_clear_error(); 166 167 } 168 169 if (ec->keylen != tkeylen) 170 { 171 /* If necessary set key length */ 172 if (EVP_CIPHER_CTX_set_key_length(ctx, ec->keylen) <= 0) 173 { 174 /* Only reveal failure if debugging so we don't 175 * leak information which may be useful in MMA. 176 */ 177 if (enc || ec->debug) 178 { 179 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, 180 CMS_R_INVALID_KEY_LENGTH); 181 goto err; 182 } 183 else 184 { 185 /* Use random key */ 186 OPENSSL_cleanse(ec->key, ec->keylen); 187 OPENSSL_free(ec->key); 188 ec->key = tkey; 189 ec->keylen = tkeylen; 190 tkey = NULL; 191 ERR_clear_error(); 192 } 193 } 194 } 195 196 if (EVP_CipherInit_ex(ctx, NULL, NULL, ec->key, piv, enc) <= 0) 197 { 198 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, 199 CMS_R_CIPHER_INITIALISATION_ERROR); 200 goto err; 201 } 202 203 if (piv) 204 { 205 calg->parameter = ASN1_TYPE_new(); 206 if (!calg->parameter) 207 { 208 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, 209 ERR_R_MALLOC_FAILURE); 210 goto err; 211 } 212 if (EVP_CIPHER_param_to_asn1(ctx, calg->parameter) <= 0) 213 { 214 CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, 215 CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR); 216 goto err; 217 } 218 } 219 ok = 1; 220 221 err: 222 if (ec->key && !keep_key) 223 { 224 OPENSSL_cleanse(ec->key, ec->keylen); 225 OPENSSL_free(ec->key); 226 ec->key = NULL; 227 } 228 if (tkey) 229 { 230 OPENSSL_cleanse(tkey, tkeylen); 231 OPENSSL_free(tkey); 232 } 233 if (ok) 234 return b; 235 BIO_free(b); 236 return NULL; 237 } 238 239 int cms_EncryptedContent_init(CMS_EncryptedContentInfo *ec, 240 const EVP_CIPHER *cipher, 241 const unsigned char *key, size_t keylen) 242 { 243 ec->cipher = cipher; 244 if (key) 245 { 246 ec->key = OPENSSL_malloc(keylen); 247 if (!ec->key) 248 return 0; 249 memcpy(ec->key, key, keylen); 250 } 251 ec->keylen = keylen; 252 if (cipher) 253 ec->contentType = OBJ_nid2obj(NID_pkcs7_data); 254 return 1; 255 } 256 257 int CMS_EncryptedData_set1_key(CMS_ContentInfo *cms, const EVP_CIPHER *ciph, 258 const unsigned char *key, size_t keylen) 259 { 260 CMS_EncryptedContentInfo *ec; 261 if (!key || !keylen) 262 { 263 CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, CMS_R_NO_KEY); 264 return 0; 265 } 266 if (ciph) 267 { 268 cms->d.encryptedData = M_ASN1_new_of(CMS_EncryptedData); 269 if (!cms->d.encryptedData) 270 { 271 CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, 272 ERR_R_MALLOC_FAILURE); 273 return 0; 274 } 275 cms->contentType = OBJ_nid2obj(NID_pkcs7_encrypted); 276 cms->d.encryptedData->version = 0; 277 } 278 else if (OBJ_obj2nid(cms->contentType) != NID_pkcs7_encrypted) 279 { 280 CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, 281 CMS_R_NOT_ENCRYPTED_DATA); 282 return 0; 283 } 284 ec = cms->d.encryptedData->encryptedContentInfo; 285 return cms_EncryptedContent_init(ec, ciph, key, keylen); 286 } 287 288 BIO *cms_EncryptedData_init_bio(CMS_ContentInfo *cms) 289 { 290 CMS_EncryptedData *enc = cms->d.encryptedData; 291 if (enc->encryptedContentInfo->cipher && enc->unprotectedAttrs) 292 enc->version = 2; 293 return cms_EncryptedContent_init_bio(enc->encryptedContentInfo); 294 } 295
