1 /* crypto/cms/cms_kari.c */
3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
6 /* ====================================================================
7 * Copyright (c) 2013 The OpenSSL Project. All rights reserved.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
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
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/)"
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29 * licensing@OpenSSL.org.
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.
35 * 6. Redistributions of any form whatsoever must retain the following
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
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,
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52 * ====================================================================
55 #include "internal/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>
64 #include "internal/asn1_int.h"
66 /* Key Agreement Recipient Info (KARI) routines */
68 int CMS_RecipientInfo_kari_get0_alg(CMS_RecipientInfo *ri,
70 ASN1_OCTET_STRING **pukm)
72 if (ri->type != CMS_RECIPINFO_AGREE) {
73 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ALG,
74 CMS_R_NOT_KEY_AGREEMENT);
78 *palg = ri->d.kari->keyEncryptionAlgorithm;
80 *pukm = ri->d.kari->ukm;
84 /* Retrieve recipient encrypted keys from a kari */
86 STACK_OF(CMS_RecipientEncryptedKey)
87 *CMS_RecipientInfo_kari_get0_reks(CMS_RecipientInfo *ri)
89 if (ri->type != CMS_RECIPINFO_AGREE) {
90 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_REKS,
91 CMS_R_NOT_KEY_AGREEMENT);
94 return ri->d.kari->recipientEncryptedKeys;
97 int CMS_RecipientInfo_kari_get0_orig_id(CMS_RecipientInfo *ri,
99 ASN1_BIT_STRING **pubkey,
100 ASN1_OCTET_STRING **keyid,
104 CMS_OriginatorIdentifierOrKey *oik;
105 if (ri->type != CMS_RECIPINFO_AGREE) {
106 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ORIG_ID,
107 CMS_R_NOT_KEY_AGREEMENT);
110 oik = ri->d.kari->originator;
121 if (oik->type == CMS_OIK_ISSUER_SERIAL) {
123 *issuer = oik->d.issuerAndSerialNumber->issuer;
125 *sno = oik->d.issuerAndSerialNumber->serialNumber;
126 } else if (oik->type == CMS_OIK_KEYIDENTIFIER) {
128 *keyid = oik->d.subjectKeyIdentifier;
129 } else if (oik->type == CMS_OIK_PUBKEY) {
131 *pubalg = oik->d.originatorKey->algorithm;
133 *pubkey = oik->d.originatorKey->publicKey;
139 int CMS_RecipientInfo_kari_orig_id_cmp(CMS_RecipientInfo *ri, X509 *cert)
141 CMS_OriginatorIdentifierOrKey *oik;
142 if (ri->type != CMS_RECIPINFO_AGREE) {
143 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ORIG_ID_CMP,
144 CMS_R_NOT_KEY_AGREEMENT);
147 oik = ri->d.kari->originator;
148 if (oik->type == CMS_OIK_ISSUER_SERIAL)
149 return cms_ias_cert_cmp(oik->d.issuerAndSerialNumber, cert);
150 else if (oik->type == CMS_OIK_KEYIDENTIFIER)
151 return cms_keyid_cert_cmp(oik->d.subjectKeyIdentifier, cert);
155 int CMS_RecipientEncryptedKey_get0_id(CMS_RecipientEncryptedKey *rek,
156 ASN1_OCTET_STRING **keyid,
157 ASN1_GENERALIZEDTIME **tm,
158 CMS_OtherKeyAttribute **other,
159 X509_NAME **issuer, ASN1_INTEGER **sno)
161 CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
162 if (rid->type == CMS_REK_ISSUER_SERIAL) {
164 *issuer = rid->d.issuerAndSerialNumber->issuer;
166 *sno = rid->d.issuerAndSerialNumber->serialNumber;
173 } else if (rid->type == CMS_REK_KEYIDENTIFIER) {
175 *keyid = rid->d.rKeyId->subjectKeyIdentifier;
177 *tm = rid->d.rKeyId->date;
179 *other = rid->d.rKeyId->other;
189 int CMS_RecipientEncryptedKey_cert_cmp(CMS_RecipientEncryptedKey *rek,
192 CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
193 if (rid->type == CMS_REK_ISSUER_SERIAL)
194 return cms_ias_cert_cmp(rid->d.issuerAndSerialNumber, cert);
195 else if (rid->type == CMS_REK_KEYIDENTIFIER)
196 return cms_keyid_cert_cmp(rid->d.rKeyId->subjectKeyIdentifier, cert);
201 int CMS_RecipientInfo_kari_set0_pkey(CMS_RecipientInfo *ri, EVP_PKEY *pk)
204 CMS_KeyAgreeRecipientInfo *kari = ri->d.kari;
206 EVP_PKEY_CTX_free(kari->pctx);
210 pctx = EVP_PKEY_CTX_new(pk, NULL);
211 if (!pctx || !EVP_PKEY_derive_init(pctx))
216 EVP_PKEY_CTX_free(pctx);
220 EVP_CIPHER_CTX *CMS_RecipientInfo_kari_get0_ctx(CMS_RecipientInfo *ri)
222 if (ri->type == CMS_RECIPINFO_AGREE)
223 return &ri->d.kari->ctx;
228 * Derive KEK and decrypt/encrypt with it to produce either the original CEK
229 * or the encrypted CEK.
232 static int cms_kek_cipher(unsigned char **pout, size_t *poutlen,
233 const unsigned char *in, size_t inlen,
234 CMS_KeyAgreeRecipientInfo *kari, int enc)
236 /* Key encryption key */
237 unsigned char kek[EVP_MAX_KEY_LENGTH];
240 unsigned char *out = NULL;
242 keklen = EVP_CIPHER_CTX_key_length(&kari->ctx);
243 if (keklen > EVP_MAX_KEY_LENGTH)
246 if (EVP_PKEY_derive(kari->pctx, kek, &keklen) <= 0)
248 /* Set KEK in context */
249 if (!EVP_CipherInit_ex(&kari->ctx, NULL, NULL, kek, NULL, enc))
251 /* obtain output length of ciphered key */
252 if (!EVP_CipherUpdate(&kari->ctx, NULL, &outlen, in, inlen))
254 out = OPENSSL_malloc(outlen);
257 if (!EVP_CipherUpdate(&kari->ctx, out, &outlen, in, inlen))
260 *poutlen = (size_t)outlen;
264 OPENSSL_cleanse(kek, keklen);
267 EVP_CIPHER_CTX_cleanup(&kari->ctx);
268 EVP_PKEY_CTX_free(kari->pctx);
273 int CMS_RecipientInfo_kari_decrypt(CMS_ContentInfo *cms,
274 CMS_RecipientInfo *ri,
275 CMS_RecipientEncryptedKey *rek)
278 unsigned char *enckey = NULL, *cek = NULL;
281 CMS_EncryptedContentInfo *ec;
282 enckeylen = rek->encryptedKey->length;
283 enckey = rek->encryptedKey->data;
284 /* Setup all parameters to derive KEK */
285 if (!cms_env_asn1_ctrl(ri, 1))
287 /* Attempt to decrypt CEK */
288 if (!cms_kek_cipher(&cek, &ceklen, enckey, enckeylen, ri->d.kari, 0))
290 ec = cms->d.envelopedData->encryptedContentInfo;
291 OPENSSL_clear_free(ec->key, ec->keylen);
301 /* Create ephemeral key and initialise context based on it */
302 static int cms_kari_create_ephemeral_key(CMS_KeyAgreeRecipientInfo *kari,
305 EVP_PKEY_CTX *pctx = NULL;
306 EVP_PKEY *ekey = NULL;
308 pctx = EVP_PKEY_CTX_new(pk, NULL);
311 if (EVP_PKEY_keygen_init(pctx) <= 0)
313 if (EVP_PKEY_keygen(pctx, &ekey) <= 0)
315 EVP_PKEY_CTX_free(pctx);
316 pctx = EVP_PKEY_CTX_new(ekey, NULL);
319 if (EVP_PKEY_derive_init(pctx) <= 0)
325 EVP_PKEY_CTX_free(pctx);
330 /* Initialise a ktri based on passed certificate and key */
332 int cms_RecipientInfo_kari_init(CMS_RecipientInfo *ri, X509 *recip,
333 EVP_PKEY *pk, unsigned int flags)
335 CMS_KeyAgreeRecipientInfo *kari;
336 CMS_RecipientEncryptedKey *rek = NULL;
338 ri->d.kari = M_ASN1_new_of(CMS_KeyAgreeRecipientInfo);
341 ri->type = CMS_RECIPINFO_AGREE;
346 rek = M_ASN1_new_of(CMS_RecipientEncryptedKey);
347 if (!sk_CMS_RecipientEncryptedKey_push(kari->recipientEncryptedKeys, rek)) {
348 M_ASN1_free_of(rek, CMS_RecipientEncryptedKey);
352 if (flags & CMS_USE_KEYID) {
353 rek->rid->type = CMS_REK_KEYIDENTIFIER;
354 rek->rid->d.rKeyId = M_ASN1_new_of(CMS_RecipientKeyIdentifier);
355 if (rek->rid->d.rKeyId == NULL)
357 if (!cms_set1_keyid(&rek->rid->d.rKeyId->subjectKeyIdentifier, recip))
360 rek->rid->type = CMS_REK_ISSUER_SERIAL;
361 if (!cms_set1_ias(&rek->rid->d.issuerAndSerialNumber, recip))
365 /* Create ephemeral key */
366 if (!cms_kari_create_ephemeral_key(kari, pk))
369 CRYPTO_add(&pk->references, 1, CRYPTO_LOCK_EVP_PKEY);
374 static int cms_wrap_init(CMS_KeyAgreeRecipientInfo *kari,
375 const EVP_CIPHER *cipher)
377 EVP_CIPHER_CTX *ctx = &kari->ctx;
378 const EVP_CIPHER *kekcipher;
379 int keylen = EVP_CIPHER_key_length(cipher);
380 /* If a suitable wrap algorithm is already set nothing to do */
381 kekcipher = EVP_CIPHER_CTX_cipher(ctx);
384 if (EVP_CIPHER_CTX_mode(ctx) != EVP_CIPH_WRAP_MODE)
389 * Pick a cipher based on content encryption cipher. If it is DES3 use
390 * DES3 wrap otherwise use AES wrap similar to key size.
392 if (EVP_CIPHER_type(cipher) == NID_des_ede3_cbc)
393 kekcipher = EVP_des_ede3_wrap();
394 else if (keylen <= 16)
395 kekcipher = EVP_aes_128_wrap();
396 else if (keylen <= 24)
397 kekcipher = EVP_aes_192_wrap();
399 kekcipher = EVP_aes_256_wrap();
400 return EVP_EncryptInit_ex(ctx, kekcipher, NULL, NULL, NULL);
403 /* Encrypt content key in key agreement recipient info */
405 int cms_RecipientInfo_kari_encrypt(CMS_ContentInfo *cms,
406 CMS_RecipientInfo *ri)
408 CMS_KeyAgreeRecipientInfo *kari;
409 CMS_EncryptedContentInfo *ec;
410 CMS_RecipientEncryptedKey *rek;
411 STACK_OF(CMS_RecipientEncryptedKey) *reks;
414 if (ri->type != CMS_RECIPINFO_AGREE) {
415 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ENCRYPT, CMS_R_NOT_KEY_AGREEMENT);
419 reks = kari->recipientEncryptedKeys;
420 ec = cms->d.envelopedData->encryptedContentInfo;
421 /* Initialise wrap algorithm parameters */
422 if (!cms_wrap_init(kari, ec->cipher))
425 * If no orignator key set up initialise for ephemeral key the public key
426 * ASN1 structure will set the actual public key value.
428 if (kari->originator->type == -1) {
429 CMS_OriginatorIdentifierOrKey *oik = kari->originator;
430 oik->type = CMS_OIK_PUBKEY;
431 oik->d.originatorKey = M_ASN1_new_of(CMS_OriginatorPublicKey);
432 if (!oik->d.originatorKey)
435 /* Initialise KDF algorithm */
436 if (!cms_env_asn1_ctrl(ri, 0))
438 /* For each rek, derive KEK, encrypt CEK */
439 for (i = 0; i < sk_CMS_RecipientEncryptedKey_num(reks); i++) {
440 unsigned char *enckey;
442 rek = sk_CMS_RecipientEncryptedKey_value(reks, i);
443 if (EVP_PKEY_derive_set_peer(kari->pctx, rek->pkey) <= 0)
445 if (!cms_kek_cipher(&enckey, &enckeylen, ec->key, ec->keylen,
448 ASN1_STRING_set0(rek->encryptedKey, enckey, enckeylen);