1 /* crypto/cms/cms_kari.c */
2 /*
3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
4 * project.
5 */
6 /* ====================================================================
7 * Copyright (c) 2013 The OpenSSL Project. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
19 * distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 * acknowledgment:
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 */
54
55 #include "cryptlib.h"
56 #include <openssl/asn1t.h>
57 #include <openssl/pem.h>
58 #include <openssl/x509v3.h>
59 #include <openssl/err.h>
60 #include <openssl/cms.h>
61 #include <openssl/rand.h>
62 #include <openssl/aes.h>
63 #include "cms_lcl.h"
64 #include "asn1_locl.h"
65
66 DECLARE_ASN1_ITEM(CMS_KeyAgreeRecipientInfo)
DECLARE_ASN1_ITEM(CMS_RecipientEncryptedKey)67 DECLARE_ASN1_ITEM(CMS_RecipientEncryptedKey)
68 DECLARE_ASN1_ITEM(CMS_OriginatorPublicKey)
69 DECLARE_ASN1_ITEM(CMS_RecipientKeyIdentifier)
70
71 /* Key Agreement Recipient Info (KARI) routines */
72
73 int CMS_RecipientInfo_kari_get0_alg(CMS_RecipientInfo *ri,
74 X509_ALGOR **palg,
75 ASN1_OCTET_STRING **pukm)
76 {
77 if (ri->type != CMS_RECIPINFO_AGREE) {
78 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ALG,
79 CMS_R_NOT_KEY_AGREEMENT);
80 return 0;
81 }
82 if (palg)
83 *palg = ri->d.kari->keyEncryptionAlgorithm;
84 if (pukm)
85 *pukm = ri->d.kari->ukm;
86 return 1;
87 }
88
89 /* Retrieve recipient encrypted keys from a kari */
90
STACK_OF(CMS_RecipientEncryptedKey)91 STACK_OF(CMS_RecipientEncryptedKey)
92 *CMS_RecipientInfo_kari_get0_reks(CMS_RecipientInfo *ri)
93 {
94 if (ri->type != CMS_RECIPINFO_AGREE) {
95 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_REKS,
96 CMS_R_NOT_KEY_AGREEMENT);
97 return NULL;
98 }
99 return ri->d.kari->recipientEncryptedKeys;
100 }
101
CMS_RecipientInfo_kari_get0_orig_id(CMS_RecipientInfo * ri,X509_ALGOR ** pubalg,ASN1_BIT_STRING ** pubkey,ASN1_OCTET_STRING ** keyid,X509_NAME ** issuer,ASN1_INTEGER ** sno)102 int CMS_RecipientInfo_kari_get0_orig_id(CMS_RecipientInfo *ri,
103 X509_ALGOR **pubalg,
104 ASN1_BIT_STRING **pubkey,
105 ASN1_OCTET_STRING **keyid,
106 X509_NAME **issuer,
107 ASN1_INTEGER **sno)
108 {
109 CMS_OriginatorIdentifierOrKey *oik;
110 if (ri->type != CMS_RECIPINFO_AGREE) {
111 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ORIG_ID,
112 CMS_R_NOT_KEY_AGREEMENT);
113 return 0;
114 }
115 oik = ri->d.kari->originator;
116 if (issuer)
117 *issuer = NULL;
118 if (sno)
119 *sno = NULL;
120 if (keyid)
121 *keyid = NULL;
122 if (pubalg)
123 *pubalg = NULL;
124 if (pubkey)
125 *pubkey = NULL;
126 if (oik->type == CMS_OIK_ISSUER_SERIAL) {
127 if (issuer)
128 *issuer = oik->d.issuerAndSerialNumber->issuer;
129 if (sno)
130 *sno = oik->d.issuerAndSerialNumber->serialNumber;
131 } else if (oik->type == CMS_OIK_KEYIDENTIFIER) {
132 if (keyid)
133 *keyid = oik->d.subjectKeyIdentifier;
134 } else if (oik->type == CMS_OIK_PUBKEY) {
135 if (pubalg)
136 *pubalg = oik->d.originatorKey->algorithm;
137 if (pubkey)
138 *pubkey = oik->d.originatorKey->publicKey;
139 } else
140 return 0;
141 return 1;
142 }
143
CMS_RecipientInfo_kari_orig_id_cmp(CMS_RecipientInfo * ri,X509 * cert)144 int CMS_RecipientInfo_kari_orig_id_cmp(CMS_RecipientInfo *ri, X509 *cert)
145 {
146 CMS_OriginatorIdentifierOrKey *oik;
147 if (ri->type != CMS_RECIPINFO_AGREE) {
148 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ORIG_ID_CMP,
149 CMS_R_NOT_KEY_AGREEMENT);
150 return -2;
151 }
152 oik = ri->d.kari->originator;
153 if (oik->type == CMS_OIK_ISSUER_SERIAL)
154 return cms_ias_cert_cmp(oik->d.issuerAndSerialNumber, cert);
155 else if (oik->type == CMS_OIK_KEYIDENTIFIER)
156 return cms_keyid_cert_cmp(oik->d.subjectKeyIdentifier, cert);
157 return -1;
158 }
159
CMS_RecipientEncryptedKey_get0_id(CMS_RecipientEncryptedKey * rek,ASN1_OCTET_STRING ** keyid,ASN1_GENERALIZEDTIME ** tm,CMS_OtherKeyAttribute ** other,X509_NAME ** issuer,ASN1_INTEGER ** sno)160 int CMS_RecipientEncryptedKey_get0_id(CMS_RecipientEncryptedKey *rek,
161 ASN1_OCTET_STRING **keyid,
162 ASN1_GENERALIZEDTIME **tm,
163 CMS_OtherKeyAttribute **other,
164 X509_NAME **issuer, ASN1_INTEGER **sno)
165 {
166 CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
167 if (rid->type == CMS_REK_ISSUER_SERIAL) {
168 if (issuer)
169 *issuer = rid->d.issuerAndSerialNumber->issuer;
170 if (sno)
171 *sno = rid->d.issuerAndSerialNumber->serialNumber;
172 if (keyid)
173 *keyid = NULL;
174 if (tm)
175 *tm = NULL;
176 if (other)
177 *other = NULL;
178 } else if (rid->type == CMS_REK_KEYIDENTIFIER) {
179 if (keyid)
180 *keyid = rid->d.rKeyId->subjectKeyIdentifier;
181 if (tm)
182 *tm = rid->d.rKeyId->date;
183 if (other)
184 *other = rid->d.rKeyId->other;
185 if (issuer)
186 *issuer = NULL;
187 if (sno)
188 *sno = NULL;
189 } else
190 return 0;
191 return 1;
192 }
193
CMS_RecipientEncryptedKey_cert_cmp(CMS_RecipientEncryptedKey * rek,X509 * cert)194 int CMS_RecipientEncryptedKey_cert_cmp(CMS_RecipientEncryptedKey *rek,
195 X509 *cert)
196 {
197 CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
198 if (rid->type == CMS_REK_ISSUER_SERIAL)
199 return cms_ias_cert_cmp(rid->d.issuerAndSerialNumber, cert);
200 else if (rid->type == CMS_REK_KEYIDENTIFIER)
201 return cms_keyid_cert_cmp(rid->d.rKeyId->subjectKeyIdentifier, cert);
202 else
203 return -1;
204 }
205
CMS_RecipientInfo_kari_set0_pkey(CMS_RecipientInfo * ri,EVP_PKEY * pk)206 int CMS_RecipientInfo_kari_set0_pkey(CMS_RecipientInfo *ri, EVP_PKEY *pk)
207 {
208 EVP_PKEY_CTX *pctx;
209 CMS_KeyAgreeRecipientInfo *kari = ri->d.kari;
210 if (kari->pctx) {
211 EVP_PKEY_CTX_free(kari->pctx);
212 kari->pctx = NULL;
213 }
214 if (!pk)
215 return 1;
216 pctx = EVP_PKEY_CTX_new(pk, NULL);
217 if (!pctx || !EVP_PKEY_derive_init(pctx))
218 goto err;
219 kari->pctx = pctx;
220 return 1;
221 err:
222 if (pctx)
223 EVP_PKEY_CTX_free(pctx);
224 return 0;
225 }
226
CMS_RecipientInfo_kari_get0_ctx(CMS_RecipientInfo * ri)227 EVP_CIPHER_CTX *CMS_RecipientInfo_kari_get0_ctx(CMS_RecipientInfo *ri)
228 {
229 if (ri->type == CMS_RECIPINFO_AGREE)
230 return &ri->d.kari->ctx;
231 return NULL;
232 }
233
234 /*
235 * Derive KEK and decrypt/encrypt with it to produce either the original CEK
236 * or the encrypted CEK.
237 */
238
cms_kek_cipher(unsigned char ** pout,size_t * poutlen,const unsigned char * in,size_t inlen,CMS_KeyAgreeRecipientInfo * kari,int enc)239 static int cms_kek_cipher(unsigned char **pout, size_t *poutlen,
240 const unsigned char *in, size_t inlen,
241 CMS_KeyAgreeRecipientInfo *kari, int enc)
242 {
243 /* Key encryption key */
244 unsigned char kek[EVP_MAX_KEY_LENGTH];
245 size_t keklen;
246 int rv = 0;
247 unsigned char *out = NULL;
248 int outlen;
249 keklen = EVP_CIPHER_CTX_key_length(&kari->ctx);
250 if (keklen > EVP_MAX_KEY_LENGTH)
251 return 0;
252 /* Derive KEK */
253 if (EVP_PKEY_derive(kari->pctx, kek, &keklen) <= 0)
254 goto err;
255 /* Set KEK in context */
256 if (!EVP_CipherInit_ex(&kari->ctx, NULL, NULL, kek, NULL, enc))
257 goto err;
258 /* obtain output length of ciphered key */
259 if (!EVP_CipherUpdate(&kari->ctx, NULL, &outlen, in, inlen))
260 goto err;
261 out = OPENSSL_malloc(outlen);
262 if (!out)
263 goto err;
264 if (!EVP_CipherUpdate(&kari->ctx, out, &outlen, in, inlen))
265 goto err;
266 *pout = out;
267 *poutlen = (size_t)outlen;
268 rv = 1;
269
270 err:
271 OPENSSL_cleanse(kek, keklen);
272 if (!rv && out)
273 OPENSSL_free(out);
274 EVP_CIPHER_CTX_cleanup(&kari->ctx);
275 EVP_PKEY_CTX_free(kari->pctx);
276 kari->pctx = NULL;
277 return rv;
278 }
279
CMS_RecipientInfo_kari_decrypt(CMS_ContentInfo * cms,CMS_RecipientInfo * ri,CMS_RecipientEncryptedKey * rek)280 int CMS_RecipientInfo_kari_decrypt(CMS_ContentInfo *cms,
281 CMS_RecipientInfo *ri,
282 CMS_RecipientEncryptedKey *rek)
283 {
284 int rv = 0;
285 unsigned char *enckey = NULL, *cek = NULL;
286 size_t enckeylen;
287 size_t ceklen;
288 CMS_EncryptedContentInfo *ec;
289 enckeylen = rek->encryptedKey->length;
290 enckey = rek->encryptedKey->data;
291 /* Setup all parameters to derive KEK */
292 if (!cms_env_asn1_ctrl(ri, 1))
293 goto err;
294 /* Attempt to decrypt CEK */
295 if (!cms_kek_cipher(&cek, &ceklen, enckey, enckeylen, ri->d.kari, 0))
296 goto err;
297 ec = cms->d.envelopedData->encryptedContentInfo;
298 if (ec->key) {
299 OPENSSL_cleanse(ec->key, ec->keylen);
300 OPENSSL_free(ec->key);
301 }
302 ec->key = cek;
303 ec->keylen = ceklen;
304 cek = NULL;
305 rv = 1;
306 err:
307 if (cek)
308 OPENSSL_free(cek);
309 return rv;
310 }
311
312 /* Create ephemeral key and initialise context based on it */
cms_kari_create_ephemeral_key(CMS_KeyAgreeRecipientInfo * kari,EVP_PKEY * pk)313 static int cms_kari_create_ephemeral_key(CMS_KeyAgreeRecipientInfo *kari,
314 EVP_PKEY *pk)
315 {
316 EVP_PKEY_CTX *pctx = NULL;
317 EVP_PKEY *ekey = NULL;
318 int rv = 0;
319 pctx = EVP_PKEY_CTX_new(pk, NULL);
320 if (!pctx)
321 goto err;
322 if (EVP_PKEY_keygen_init(pctx) <= 0)
323 goto err;
324 if (EVP_PKEY_keygen(pctx, &ekey) <= 0)
325 goto err;
326 EVP_PKEY_CTX_free(pctx);
327 pctx = EVP_PKEY_CTX_new(ekey, NULL);
328 if (!pctx)
329 goto err;
330 if (EVP_PKEY_derive_init(pctx) <= 0)
331 goto err;
332 kari->pctx = pctx;
333 rv = 1;
334 err:
335 if (!rv && pctx)
336 EVP_PKEY_CTX_free(pctx);
337 if (ekey)
338 EVP_PKEY_free(ekey);
339 return rv;
340 }
341
342 /* Initialise a ktri based on passed certificate and key */
343
cms_RecipientInfo_kari_init(CMS_RecipientInfo * ri,X509 * recip,EVP_PKEY * pk,unsigned int flags)344 int cms_RecipientInfo_kari_init(CMS_RecipientInfo *ri, X509 *recip,
345 EVP_PKEY *pk, unsigned int flags)
346 {
347 CMS_KeyAgreeRecipientInfo *kari;
348 CMS_RecipientEncryptedKey *rek = NULL;
349
350 ri->d.kari = M_ASN1_new_of(CMS_KeyAgreeRecipientInfo);
351 if (!ri->d.kari)
352 return 0;
353 ri->type = CMS_RECIPINFO_AGREE;
354
355 kari = ri->d.kari;
356 kari->version = 3;
357
358 rek = M_ASN1_new_of(CMS_RecipientEncryptedKey);
359 if (!sk_CMS_RecipientEncryptedKey_push(kari->recipientEncryptedKeys, rek)) {
360 M_ASN1_free_of(rek, CMS_RecipientEncryptedKey);
361 return 0;
362 }
363
364 if (flags & CMS_USE_KEYID) {
365 rek->rid->type = CMS_REK_KEYIDENTIFIER;
366 rek->rid->d.rKeyId = M_ASN1_new_of(CMS_RecipientKeyIdentifier);
367 if (rek->rid->d.rKeyId == NULL)
368 return 0;
369 if (!cms_set1_keyid(&rek->rid->d.rKeyId->subjectKeyIdentifier, recip))
370 return 0;
371 } else {
372 rek->rid->type = CMS_REK_ISSUER_SERIAL;
373 if (!cms_set1_ias(&rek->rid->d.issuerAndSerialNumber, recip))
374 return 0;
375 }
376
377 /* Create ephemeral key */
378 if (!cms_kari_create_ephemeral_key(kari, pk))
379 return 0;
380
381 CRYPTO_add(&pk->references, 1, CRYPTO_LOCK_EVP_PKEY);
382 rek->pkey = pk;
383 return 1;
384 }
385
cms_wrap_init(CMS_KeyAgreeRecipientInfo * kari,const EVP_CIPHER * cipher)386 static int cms_wrap_init(CMS_KeyAgreeRecipientInfo *kari,
387 const EVP_CIPHER *cipher)
388 {
389 EVP_CIPHER_CTX *ctx = &kari->ctx;
390 const EVP_CIPHER *kekcipher;
391 int keylen = EVP_CIPHER_key_length(cipher);
392 /* If a suitable wrap algorithm is already set nothing to do */
393 kekcipher = EVP_CIPHER_CTX_cipher(ctx);
394
395 if (kekcipher) {
396 if (EVP_CIPHER_CTX_mode(ctx) != EVP_CIPH_WRAP_MODE)
397 return 0;
398 return 1;
399 }
400 /*
401 * Pick a cipher based on content encryption cipher. If it is DES3 use
402 * DES3 wrap otherwise use AES wrap similar to key size.
403 */
404 #ifndef OPENSSL_NO_DES
405 if (EVP_CIPHER_type(cipher) == NID_des_ede3_cbc)
406 kekcipher = EVP_des_ede3_wrap();
407 else
408 #endif
409 if (keylen <= 16)
410 kekcipher = EVP_aes_128_wrap();
411 else if (keylen <= 24)
412 kekcipher = EVP_aes_192_wrap();
413 else
414 kekcipher = EVP_aes_256_wrap();
415 return EVP_EncryptInit_ex(ctx, kekcipher, NULL, NULL, NULL);
416 }
417
418 /* Encrypt content key in key agreement recipient info */
419
cms_RecipientInfo_kari_encrypt(CMS_ContentInfo * cms,CMS_RecipientInfo * ri)420 int cms_RecipientInfo_kari_encrypt(CMS_ContentInfo *cms,
421 CMS_RecipientInfo *ri)
422 {
423 CMS_KeyAgreeRecipientInfo *kari;
424 CMS_EncryptedContentInfo *ec;
425 CMS_RecipientEncryptedKey *rek;
426 STACK_OF(CMS_RecipientEncryptedKey) *reks;
427 int i;
428
429 if (ri->type != CMS_RECIPINFO_AGREE) {
430 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ENCRYPT, CMS_R_NOT_KEY_AGREEMENT);
431 return 0;
432 }
433 kari = ri->d.kari;
434 reks = kari->recipientEncryptedKeys;
435 ec = cms->d.envelopedData->encryptedContentInfo;
436 /* Initialise wrap algorithm parameters */
437 if (!cms_wrap_init(kari, ec->cipher))
438 return 0;
439 /*
440 * If no orignator key set up initialise for ephemeral key the public key
441 * ASN1 structure will set the actual public key value.
442 */
443 if (kari->originator->type == -1) {
444 CMS_OriginatorIdentifierOrKey *oik = kari->originator;
445 oik->type = CMS_OIK_PUBKEY;
446 oik->d.originatorKey = M_ASN1_new_of(CMS_OriginatorPublicKey);
447 if (!oik->d.originatorKey)
448 return 0;
449 }
450 /* Initialise KDF algorithm */
451 if (!cms_env_asn1_ctrl(ri, 0))
452 return 0;
453 /* For each rek, derive KEK, encrypt CEK */
454 for (i = 0; i < sk_CMS_RecipientEncryptedKey_num(reks); i++) {
455 unsigned char *enckey;
456 size_t enckeylen;
457 rek = sk_CMS_RecipientEncryptedKey_value(reks, i);
458 if (EVP_PKEY_derive_set_peer(kari->pctx, rek->pkey) <= 0)
459 return 0;
460 if (!cms_kek_cipher(&enckey, &enckeylen, ec->key, ec->keylen,
461 kari, 1))
462 return 0;
463 ASN1_STRING_set0(rek->encryptedKey, enckey, enckeylen);
464 }
465
466 return 1;
467
468 }
469