2 * Copyright 2013-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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
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/aes.h>
18 #include "internal/asn1_int.h"
20 /* Key Agreement Recipient Info (KARI) routines */
22 int CMS_RecipientInfo_kari_get0_alg(CMS_RecipientInfo
*ri
,
24 ASN1_OCTET_STRING
**pukm
)
26 if (ri
->type
!= CMS_RECIPINFO_AGREE
) {
27 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ALG
,
28 CMS_R_NOT_KEY_AGREEMENT
);
32 *palg
= ri
->d
.kari
->keyEncryptionAlgorithm
;
34 *pukm
= ri
->d
.kari
->ukm
;
38 /* Retrieve recipient encrypted keys from a kari */
40 STACK_OF(CMS_RecipientEncryptedKey
)
41 *CMS_RecipientInfo_kari_get0_reks(CMS_RecipientInfo
*ri
)
43 if (ri
->type
!= CMS_RECIPINFO_AGREE
) {
44 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_REKS
,
45 CMS_R_NOT_KEY_AGREEMENT
);
48 return ri
->d
.kari
->recipientEncryptedKeys
;
51 int CMS_RecipientInfo_kari_get0_orig_id(CMS_RecipientInfo
*ri
,
53 ASN1_BIT_STRING
**pubkey
,
54 ASN1_OCTET_STRING
**keyid
,
58 CMS_OriginatorIdentifierOrKey
*oik
;
59 if (ri
->type
!= CMS_RECIPINFO_AGREE
) {
60 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ORIG_ID
,
61 CMS_R_NOT_KEY_AGREEMENT
);
64 oik
= ri
->d
.kari
->originator
;
75 if (oik
->type
== CMS_OIK_ISSUER_SERIAL
) {
77 *issuer
= oik
->d
.issuerAndSerialNumber
->issuer
;
79 *sno
= oik
->d
.issuerAndSerialNumber
->serialNumber
;
80 } else if (oik
->type
== CMS_OIK_KEYIDENTIFIER
) {
82 *keyid
= oik
->d
.subjectKeyIdentifier
;
83 } else if (oik
->type
== CMS_OIK_PUBKEY
) {
85 *pubalg
= oik
->d
.originatorKey
->algorithm
;
87 *pubkey
= oik
->d
.originatorKey
->publicKey
;
93 int CMS_RecipientInfo_kari_orig_id_cmp(CMS_RecipientInfo
*ri
, X509
*cert
)
95 CMS_OriginatorIdentifierOrKey
*oik
;
96 if (ri
->type
!= CMS_RECIPINFO_AGREE
) {
97 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ORIG_ID_CMP
,
98 CMS_R_NOT_KEY_AGREEMENT
);
101 oik
= ri
->d
.kari
->originator
;
102 if (oik
->type
== CMS_OIK_ISSUER_SERIAL
)
103 return cms_ias_cert_cmp(oik
->d
.issuerAndSerialNumber
, cert
);
104 else if (oik
->type
== CMS_OIK_KEYIDENTIFIER
)
105 return cms_keyid_cert_cmp(oik
->d
.subjectKeyIdentifier
, cert
);
109 int CMS_RecipientEncryptedKey_get0_id(CMS_RecipientEncryptedKey
*rek
,
110 ASN1_OCTET_STRING
**keyid
,
111 ASN1_GENERALIZEDTIME
**tm
,
112 CMS_OtherKeyAttribute
**other
,
113 X509_NAME
**issuer
, ASN1_INTEGER
**sno
)
115 CMS_KeyAgreeRecipientIdentifier
*rid
= rek
->rid
;
116 if (rid
->type
== CMS_REK_ISSUER_SERIAL
) {
118 *issuer
= rid
->d
.issuerAndSerialNumber
->issuer
;
120 *sno
= rid
->d
.issuerAndSerialNumber
->serialNumber
;
127 } else if (rid
->type
== CMS_REK_KEYIDENTIFIER
) {
129 *keyid
= rid
->d
.rKeyId
->subjectKeyIdentifier
;
131 *tm
= rid
->d
.rKeyId
->date
;
133 *other
= rid
->d
.rKeyId
->other
;
143 int CMS_RecipientEncryptedKey_cert_cmp(CMS_RecipientEncryptedKey
*rek
,
146 CMS_KeyAgreeRecipientIdentifier
*rid
= rek
->rid
;
147 if (rid
->type
== CMS_REK_ISSUER_SERIAL
)
148 return cms_ias_cert_cmp(rid
->d
.issuerAndSerialNumber
, cert
);
149 else if (rid
->type
== CMS_REK_KEYIDENTIFIER
)
150 return cms_keyid_cert_cmp(rid
->d
.rKeyId
->subjectKeyIdentifier
, cert
);
155 int CMS_RecipientInfo_kari_set0_pkey(CMS_RecipientInfo
*ri
, EVP_PKEY
*pk
)
158 CMS_KeyAgreeRecipientInfo
*kari
= ri
->d
.kari
;
160 EVP_PKEY_CTX_free(kari
->pctx
);
164 pctx
= EVP_PKEY_CTX_new(pk
, NULL
);
165 if (!pctx
|| !EVP_PKEY_derive_init(pctx
))
170 EVP_PKEY_CTX_free(pctx
);
174 EVP_CIPHER_CTX
*CMS_RecipientInfo_kari_get0_ctx(CMS_RecipientInfo
*ri
)
176 if (ri
->type
== CMS_RECIPINFO_AGREE
)
177 return ri
->d
.kari
->ctx
;
182 * Derive KEK and decrypt/encrypt with it to produce either the original CEK
183 * or the encrypted CEK.
186 static int cms_kek_cipher(unsigned char **pout
, size_t *poutlen
,
187 const unsigned char *in
, size_t inlen
,
188 CMS_KeyAgreeRecipientInfo
*kari
, int enc
)
190 /* Key encryption key */
191 unsigned char kek
[EVP_MAX_KEY_LENGTH
];
194 unsigned char *out
= NULL
;
196 keklen
= EVP_CIPHER_CTX_key_length(kari
->ctx
);
197 if (keklen
> EVP_MAX_KEY_LENGTH
)
200 if (EVP_PKEY_derive(kari
->pctx
, kek
, &keklen
) <= 0)
202 /* Set KEK in context */
203 if (!EVP_CipherInit_ex(kari
->ctx
, NULL
, NULL
, kek
, NULL
, enc
))
205 /* obtain output length of ciphered key */
206 if (!EVP_CipherUpdate(kari
->ctx
, NULL
, &outlen
, in
, inlen
))
208 out
= OPENSSL_malloc(outlen
);
211 if (!EVP_CipherUpdate(kari
->ctx
, out
, &outlen
, in
, inlen
))
214 *poutlen
= (size_t)outlen
;
218 OPENSSL_cleanse(kek
, keklen
);
221 EVP_CIPHER_CTX_reset(kari
->ctx
);
222 /* FIXME: WHY IS kari->pctx freed here? /RL */
223 EVP_PKEY_CTX_free(kari
->pctx
);
228 int CMS_RecipientInfo_kari_decrypt(CMS_ContentInfo
*cms
,
229 CMS_RecipientInfo
*ri
,
230 CMS_RecipientEncryptedKey
*rek
)
233 unsigned char *enckey
= NULL
, *cek
= NULL
;
236 CMS_EncryptedContentInfo
*ec
;
237 enckeylen
= rek
->encryptedKey
->length
;
238 enckey
= rek
->encryptedKey
->data
;
239 /* Setup all parameters to derive KEK */
240 if (!cms_env_asn1_ctrl(ri
, 1))
242 /* Attempt to decrypt CEK */
243 if (!cms_kek_cipher(&cek
, &ceklen
, enckey
, enckeylen
, ri
->d
.kari
, 0))
245 ec
= cms
->d
.envelopedData
->encryptedContentInfo
;
246 OPENSSL_clear_free(ec
->key
, ec
->keylen
);
256 /* Create ephemeral key and initialise context based on it */
257 static int cms_kari_create_ephemeral_key(CMS_KeyAgreeRecipientInfo
*kari
,
260 EVP_PKEY_CTX
*pctx
= NULL
;
261 EVP_PKEY
*ekey
= NULL
;
263 pctx
= EVP_PKEY_CTX_new(pk
, NULL
);
266 if (EVP_PKEY_keygen_init(pctx
) <= 0)
268 if (EVP_PKEY_keygen(pctx
, &ekey
) <= 0)
270 EVP_PKEY_CTX_free(pctx
);
271 pctx
= EVP_PKEY_CTX_new(ekey
, NULL
);
274 if (EVP_PKEY_derive_init(pctx
) <= 0)
280 EVP_PKEY_CTX_free(pctx
);
285 /* Initialise a ktri based on passed certificate and key */
287 int cms_RecipientInfo_kari_init(CMS_RecipientInfo
*ri
, X509
*recip
,
288 EVP_PKEY
*pk
, unsigned int flags
)
290 CMS_KeyAgreeRecipientInfo
*kari
;
291 CMS_RecipientEncryptedKey
*rek
= NULL
;
293 ri
->d
.kari
= M_ASN1_new_of(CMS_KeyAgreeRecipientInfo
);
296 ri
->type
= CMS_RECIPINFO_AGREE
;
301 rek
= M_ASN1_new_of(CMS_RecipientEncryptedKey
);
302 if (!sk_CMS_RecipientEncryptedKey_push(kari
->recipientEncryptedKeys
, rek
)) {
303 M_ASN1_free_of(rek
, CMS_RecipientEncryptedKey
);
307 if (flags
& CMS_USE_KEYID
) {
308 rek
->rid
->type
= CMS_REK_KEYIDENTIFIER
;
309 rek
->rid
->d
.rKeyId
= M_ASN1_new_of(CMS_RecipientKeyIdentifier
);
310 if (rek
->rid
->d
.rKeyId
== NULL
)
312 if (!cms_set1_keyid(&rek
->rid
->d
.rKeyId
->subjectKeyIdentifier
, recip
))
315 rek
->rid
->type
= CMS_REK_ISSUER_SERIAL
;
316 if (!cms_set1_ias(&rek
->rid
->d
.issuerAndSerialNumber
, recip
))
320 /* Create ephemeral key */
321 if (!cms_kari_create_ephemeral_key(kari
, pk
))
329 static int cms_wrap_init(CMS_KeyAgreeRecipientInfo
*kari
,
330 const EVP_CIPHER
*cipher
)
332 EVP_CIPHER_CTX
*ctx
= kari
->ctx
;
333 const EVP_CIPHER
*kekcipher
;
334 int keylen
= EVP_CIPHER_key_length(cipher
);
335 /* If a suitable wrap algorithm is already set nothing to do */
336 kekcipher
= EVP_CIPHER_CTX_cipher(ctx
);
339 if (EVP_CIPHER_CTX_mode(ctx
) != EVP_CIPH_WRAP_MODE
)
344 * Pick a cipher based on content encryption cipher. If it is DES3 use
345 * DES3 wrap otherwise use AES wrap similar to key size.
347 #ifndef OPENSSL_NO_DES
348 if (EVP_CIPHER_type(cipher
) == NID_des_ede3_cbc
)
349 kekcipher
= EVP_des_ede3_wrap();
353 kekcipher
= EVP_aes_128_wrap();
354 else if (keylen
<= 24)
355 kekcipher
= EVP_aes_192_wrap();
357 kekcipher
= EVP_aes_256_wrap();
358 return EVP_EncryptInit_ex(ctx
, kekcipher
, NULL
, NULL
, NULL
);
361 /* Encrypt content key in key agreement recipient info */
363 int cms_RecipientInfo_kari_encrypt(CMS_ContentInfo
*cms
,
364 CMS_RecipientInfo
*ri
)
366 CMS_KeyAgreeRecipientInfo
*kari
;
367 CMS_EncryptedContentInfo
*ec
;
368 CMS_RecipientEncryptedKey
*rek
;
369 STACK_OF(CMS_RecipientEncryptedKey
) *reks
;
372 if (ri
->type
!= CMS_RECIPINFO_AGREE
) {
373 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ENCRYPT
, CMS_R_NOT_KEY_AGREEMENT
);
377 reks
= kari
->recipientEncryptedKeys
;
378 ec
= cms
->d
.envelopedData
->encryptedContentInfo
;
379 /* Initialise wrap algorithm parameters */
380 if (!cms_wrap_init(kari
, ec
->cipher
))
383 * If no originator key set up initialise for ephemeral key the public key
384 * ASN1 structure will set the actual public key value.
386 if (kari
->originator
->type
== -1) {
387 CMS_OriginatorIdentifierOrKey
*oik
= kari
->originator
;
388 oik
->type
= CMS_OIK_PUBKEY
;
389 oik
->d
.originatorKey
= M_ASN1_new_of(CMS_OriginatorPublicKey
);
390 if (!oik
->d
.originatorKey
)
393 /* Initialise KDF algorithm */
394 if (!cms_env_asn1_ctrl(ri
, 0))
396 /* For each rek, derive KEK, encrypt CEK */
397 for (i
= 0; i
< sk_CMS_RecipientEncryptedKey_num(reks
); i
++) {
398 unsigned char *enckey
;
400 rek
= sk_CMS_RecipientEncryptedKey_value(reks
, i
);
401 if (EVP_PKEY_derive_set_peer(kari
->pctx
, rek
->pkey
) <= 0)
403 if (!cms_kek_cipher(&enckey
, &enckeylen
, ec
->key
, ec
->keylen
,
406 ASN1_STRING_set0(rek
->encryptedKey
, enckey
, enckeylen
);