2 * Copyright 2006-2021 The OpenSSL Project Authors. All Rights Reserved.
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
11 #include <openssl/cms.h>
12 #include <openssl/dh.h>
13 #include <openssl/err.h>
14 #include <openssl/core_names.h>
15 #include "cms_local.h"
16 #include "crypto/evp.h"
18 static int dh_cms_set_peerkey(EVP_PKEY_CTX
*pctx
,
19 X509_ALGOR
*alg
, ASN1_BIT_STRING
*pubkey
)
21 const ASN1_OBJECT
*aoid
;
24 ASN1_INTEGER
*public_key
= NULL
;
26 EVP_PKEY
*pkpeer
= NULL
, *pk
= NULL
;
28 const unsigned char *p
;
29 unsigned char *buf
= NULL
;
32 X509_ALGOR_get0(&aoid
, &atype
, &aval
, alg
);
33 if (OBJ_obj2nid(aoid
) != NID_dhpublicnumber
)
35 /* Only absent parameters allowed in RFC XXXX */
36 if (atype
!= V_ASN1_UNDEF
&& atype
== V_ASN1_NULL
)
39 pk
= EVP_PKEY_CTX_get0_pkey(pctx
);
40 if (pk
== NULL
|| !EVP_PKEY_is_a(pk
, "DHX"))
44 plen
= ASN1_STRING_length(pubkey
);
45 p
= ASN1_STRING_get0_data(pubkey
);
46 if (p
== NULL
|| plen
== 0)
49 if ((public_key
= d2i_ASN1_INTEGER(NULL
, &p
, plen
)) == NULL
)
52 * Pad to full p parameter size as that is checked by
53 * EVP_PKEY_set1_encoded_public_key()
55 plen
= EVP_PKEY_size(pk
);
56 if ((bnpub
= ASN1_INTEGER_to_BN(public_key
, NULL
)) == NULL
)
58 if ((buf
= OPENSSL_malloc(plen
)) == NULL
)
60 if (BN_bn2binpad(bnpub
, buf
, plen
) < 0)
63 pkpeer
= EVP_PKEY_new();
65 || !EVP_PKEY_copy_parameters(pkpeer
, pk
)
66 || !EVP_PKEY_set1_encoded_public_key(pkpeer
, buf
, plen
))
69 if (EVP_PKEY_derive_set_peer(pctx
, pkpeer
) > 0)
72 ASN1_INTEGER_free(public_key
);
75 EVP_PKEY_free(pkpeer
);
79 static int dh_cms_set_shared_info(EVP_PKEY_CTX
*pctx
, CMS_RecipientInfo
*ri
)
82 X509_ALGOR
*alg
, *kekalg
= NULL
;
83 ASN1_OCTET_STRING
*ukm
;
84 const unsigned char *p
;
85 unsigned char *dukm
= NULL
;
88 EVP_CIPHER
*kekcipher
= NULL
;
89 EVP_CIPHER_CTX
*kekctx
;
92 if (!CMS_RecipientInfo_kari_get0_alg(ri
, &alg
, &ukm
))
96 * For DH we only have one OID permissible. If ever any more get defined
97 * we will need something cleverer.
99 if (OBJ_obj2nid(alg
->algorithm
) != NID_id_smime_alg_ESDH
) {
100 ERR_raise(ERR_LIB_CMS
, CMS_R_KDF_PARAMETER_ERROR
);
104 if (EVP_PKEY_CTX_set_dh_kdf_type(pctx
, EVP_PKEY_DH_KDF_X9_42
) <= 0
105 || EVP_PKEY_CTX_set_dh_kdf_md(pctx
, EVP_sha1()) <= 0)
108 if (alg
->parameter
->type
!= V_ASN1_SEQUENCE
)
111 p
= alg
->parameter
->value
.sequence
->data
;
112 plen
= alg
->parameter
->value
.sequence
->length
;
113 kekalg
= d2i_X509_ALGOR(NULL
, &p
, plen
);
116 kekctx
= CMS_RecipientInfo_kari_get0_ctx(ri
);
120 name
= OBJ_nid2sn(OBJ_obj2nid(kekalg
->algorithm
));
124 kekcipher
= EVP_CIPHER_fetch(pctx
->libctx
, name
, pctx
->propquery
);
125 if (kekcipher
== NULL
|| EVP_CIPHER_mode(kekcipher
) != EVP_CIPH_WRAP_MODE
)
127 if (!EVP_EncryptInit_ex(kekctx
, kekcipher
, NULL
, NULL
, NULL
))
129 if (EVP_CIPHER_asn1_to_param(kekctx
, kekalg
->parameter
) <= 0)
132 keylen
= EVP_CIPHER_CTX_key_length(kekctx
);
133 if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx
, keylen
) <= 0)
135 /* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
136 if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx
,
137 OBJ_nid2obj(EVP_CIPHER_type(kekcipher
)))
142 dukmlen
= ASN1_STRING_length(ukm
);
143 dukm
= OPENSSL_memdup(ASN1_STRING_get0_data(ukm
), dukmlen
);
148 if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx
, dukm
, dukmlen
) <= 0)
154 X509_ALGOR_free(kekalg
);
155 EVP_CIPHER_free(kekcipher
);
160 static int dh_cms_decrypt(CMS_RecipientInfo
*ri
)
162 EVP_PKEY_CTX
*pctx
= CMS_RecipientInfo_get0_pkey_ctx(ri
);
166 /* See if we need to set peer key */
167 if (!EVP_PKEY_CTX_get0_peerkey(pctx
)) {
169 ASN1_BIT_STRING
*pubkey
;
171 if (!CMS_RecipientInfo_kari_get0_orig_id(ri
, &alg
, &pubkey
,
174 if (alg
== NULL
|| pubkey
== NULL
)
176 if (!dh_cms_set_peerkey(pctx
, alg
, pubkey
)) {
177 ERR_raise(ERR_LIB_CMS
, CMS_R_PEER_KEY_ERROR
);
181 /* Set DH derivation parameters and initialise unwrap context */
182 if (!dh_cms_set_shared_info(pctx
, ri
)) {
183 ERR_raise(ERR_LIB_CMS
, CMS_R_SHARED_INFO_ERROR
);
189 static int dh_cms_encrypt(CMS_RecipientInfo
*ri
)
195 X509_ALGOR
*talg
, *wrap_alg
= NULL
;
196 const ASN1_OBJECT
*aoid
;
197 ASN1_BIT_STRING
*pubkey
;
198 ASN1_STRING
*wrap_str
;
199 ASN1_OCTET_STRING
*ukm
;
200 unsigned char *penc
= NULL
, *dukm
= NULL
;
204 int kdf_type
, wrap_nid
;
205 const EVP_MD
*kdf_md
;
207 pctx
= CMS_RecipientInfo_get0_pkey_ctx(ri
);
210 /* Get ephemeral key */
211 pkey
= EVP_PKEY_CTX_get0_pkey(pctx
);
212 if (!CMS_RecipientInfo_kari_get0_orig_id(ri
, &talg
, &pubkey
,
216 /* Is everything uninitialised? */
217 X509_ALGOR_get0(&aoid
, NULL
, NULL
, talg
);
218 if (aoid
== OBJ_nid2obj(NID_undef
)) {
219 BIGNUM
*bn_pub_key
= NULL
;
222 if (!EVP_PKEY_get_bn_param(pkey
, OSSL_PKEY_PARAM_PUB_KEY
, &bn_pub_key
))
225 pubk
= BN_to_ASN1_INTEGER(bn_pub_key
, NULL
);
231 penclen
= i2d_ASN1_INTEGER(pubk
, &penc
);
232 ASN1_INTEGER_free(pubk
);
235 ASN1_STRING_set0(pubkey
, penc
, penclen
);
236 pubkey
->flags
&= ~(ASN1_STRING_FLAG_BITS_LEFT
| 0x07);
237 pubkey
->flags
|= ASN1_STRING_FLAG_BITS_LEFT
;
240 X509_ALGOR_set0(talg
, OBJ_nid2obj(NID_dhpublicnumber
),
244 /* See if custom parameters set */
245 kdf_type
= EVP_PKEY_CTX_get_dh_kdf_type(pctx
);
246 if (kdf_type
<= 0 || !EVP_PKEY_CTX_get_dh_kdf_md(pctx
, &kdf_md
))
249 if (kdf_type
== EVP_PKEY_DH_KDF_NONE
) {
250 kdf_type
= EVP_PKEY_DH_KDF_X9_42
;
251 if (EVP_PKEY_CTX_set_dh_kdf_type(pctx
, kdf_type
) <= 0)
253 } else if (kdf_type
!= EVP_PKEY_DH_KDF_X9_42
)
256 if (kdf_md
== NULL
) {
257 /* Only SHA1 supported */
259 if (EVP_PKEY_CTX_set_dh_kdf_md(pctx
, kdf_md
) <= 0)
261 } else if (EVP_MD_type(kdf_md
) != NID_sha1
)
262 /* Unsupported digest */
265 if (!CMS_RecipientInfo_kari_get0_alg(ri
, &talg
, &ukm
))
269 ctx
= CMS_RecipientInfo_kari_get0_ctx(ri
);
270 wrap_nid
= EVP_CIPHER_CTX_type(ctx
);
271 if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx
, OBJ_nid2obj(wrap_nid
)) <= 0)
273 keylen
= EVP_CIPHER_CTX_key_length(ctx
);
275 /* Package wrap algorithm in an AlgorithmIdentifier */
277 wrap_alg
= X509_ALGOR_new();
278 if (wrap_alg
== NULL
)
280 wrap_alg
->algorithm
= OBJ_nid2obj(wrap_nid
);
281 wrap_alg
->parameter
= ASN1_TYPE_new();
282 if (wrap_alg
->parameter
== NULL
)
284 if (EVP_CIPHER_param_to_asn1(ctx
, wrap_alg
->parameter
) <= 0)
286 if (ASN1_TYPE_get(wrap_alg
->parameter
) == NID_undef
) {
287 ASN1_TYPE_free(wrap_alg
->parameter
);
288 wrap_alg
->parameter
= NULL
;
291 if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx
, keylen
) <= 0)
295 dukmlen
= ASN1_STRING_length(ukm
);
296 dukm
= OPENSSL_memdup(ASN1_STRING_get0_data(ukm
), dukmlen
);
301 if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx
, dukm
, dukmlen
) <= 0)
306 * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
307 * of another AlgorithmIdentifier.
310 penclen
= i2d_X509_ALGOR(wrap_alg
, &penc
);
311 if (penc
== NULL
|| penclen
== 0)
313 wrap_str
= ASN1_STRING_new();
314 if (wrap_str
== NULL
)
316 ASN1_STRING_set0(wrap_str
, penc
, penclen
);
318 X509_ALGOR_set0(talg
, OBJ_nid2obj(NID_id_smime_alg_ESDH
),
319 V_ASN1_SEQUENCE
, wrap_str
);
325 X509_ALGOR_free(wrap_alg
);
330 int ossl_cms_dh_envelope(CMS_RecipientInfo
*ri
, int decrypt
)
332 assert(decrypt
== 0 || decrypt
== 1);
335 return dh_cms_decrypt(ri
);
338 return dh_cms_encrypt(ri
);
340 ERR_raise(ERR_LIB_CMS
, CMS_R_NOT_SUPPORTED_FOR_THIS_KEY_TYPE
);