1 /*
2 * Copyright 2006-2023 The OpenSSL Project Authors. All Rights Reserved.
3 *
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
8 */
9
10 #include <assert.h>
11 #include <limits.h>
12 #include <openssl/cms.h>
13 #include <openssl/err.h>
14 #include <openssl/decoder.h>
15 #include "internal/sizes.h"
16 #include "crypto/evp.h"
17 #include "cms_local.h"
18
pkey_type2param(int ptype,const void * pval,OSSL_LIB_CTX * libctx,const char * propq)19 static EVP_PKEY *pkey_type2param(int ptype, const void *pval,
20 OSSL_LIB_CTX *libctx, const char *propq)
21 {
22 EVP_PKEY *pkey = NULL;
23 EVP_PKEY_CTX *pctx = NULL;
24 OSSL_DECODER_CTX *ctx = NULL;
25
26 if (ptype == V_ASN1_SEQUENCE) {
27 const ASN1_STRING *pstr = pval;
28 const unsigned char *pm = pstr->data;
29 size_t pmlen = (size_t)pstr->length;
30 int selection = OSSL_KEYMGMT_SELECT_ALL_PARAMETERS;
31
32 ctx = OSSL_DECODER_CTX_new_for_pkey(&pkey, "DER", NULL, "EC",
33 selection, libctx, propq);
34 if (ctx == NULL)
35 goto err;
36
37 if (!OSSL_DECODER_from_data(ctx, &pm, &pmlen)) {
38 ERR_raise(ERR_LIB_CMS, CMS_R_DECODE_ERROR);
39 goto err;
40 }
41 OSSL_DECODER_CTX_free(ctx);
42 return pkey;
43 } else if (ptype == V_ASN1_OBJECT) {
44 const ASN1_OBJECT *poid = pval;
45 char groupname[OSSL_MAX_NAME_SIZE];
46
47 /* type == V_ASN1_OBJECT => the parameters are given by an asn1 OID */
48 pctx = EVP_PKEY_CTX_new_from_name(libctx, "EC", propq);
49 if (pctx == NULL || EVP_PKEY_paramgen_init(pctx) <= 0)
50 goto err;
51 if (OBJ_obj2txt(groupname, sizeof(groupname), poid, 0) <= 0
52 || EVP_PKEY_CTX_set_group_name(pctx, groupname) <= 0) {
53 ERR_raise(ERR_LIB_CMS, CMS_R_DECODE_ERROR);
54 goto err;
55 }
56 if (EVP_PKEY_paramgen(pctx, &pkey) <= 0)
57 goto err;
58 EVP_PKEY_CTX_free(pctx);
59 return pkey;
60 }
61
62 ERR_raise(ERR_LIB_CMS, CMS_R_DECODE_ERROR);
63 return NULL;
64
65 err:
66 EVP_PKEY_free(pkey);
67 EVP_PKEY_CTX_free(pctx);
68 OSSL_DECODER_CTX_free(ctx);
69 return NULL;
70 }
71
ecdh_cms_set_peerkey(EVP_PKEY_CTX * pctx,X509_ALGOR * alg,ASN1_BIT_STRING * pubkey)72 static int ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
73 X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
74 {
75 const ASN1_OBJECT *aoid;
76 int atype;
77 const void *aval;
78 int rv = 0;
79 EVP_PKEY *pkpeer = NULL;
80 const unsigned char *p;
81 int plen;
82
83 X509_ALGOR_get0(&aoid, &atype, &aval, alg);
84 if (OBJ_obj2nid(aoid) != NID_X9_62_id_ecPublicKey)
85 goto err;
86
87 /* If absent parameters get group from main key */
88 if (atype == V_ASN1_UNDEF || atype == V_ASN1_NULL) {
89 EVP_PKEY *pk;
90
91 pk = EVP_PKEY_CTX_get0_pkey(pctx);
92 if (pk == NULL)
93 goto err;
94
95 pkpeer = EVP_PKEY_new();
96 if (pkpeer == NULL)
97 goto err;
98 if (!EVP_PKEY_copy_parameters(pkpeer, pk))
99 goto err;
100 } else {
101 pkpeer = pkey_type2param(atype, aval,
102 EVP_PKEY_CTX_get0_libctx(pctx),
103 EVP_PKEY_CTX_get0_propq(pctx));
104 if (pkpeer == NULL)
105 goto err;
106 }
107 /* We have parameters now set public key */
108 plen = ASN1_STRING_length(pubkey);
109 p = ASN1_STRING_get0_data(pubkey);
110 if (p == NULL || plen == 0)
111 goto err;
112
113 if (!EVP_PKEY_set1_encoded_public_key(pkpeer, p, plen))
114 goto err;
115
116 if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
117 rv = 1;
118 err:
119 EVP_PKEY_free(pkpeer);
120 return rv;
121 }
122
123 /* Set KDF parameters based on KDF NID */
ecdh_cms_set_kdf_param(EVP_PKEY_CTX * pctx,int eckdf_nid)124 static int ecdh_cms_set_kdf_param(EVP_PKEY_CTX *pctx, int eckdf_nid)
125 {
126 int kdf_nid, kdfmd_nid, cofactor;
127 const EVP_MD *kdf_md;
128
129 if (eckdf_nid == NID_undef)
130 return 0;
131
132 /* Lookup KDF type, cofactor mode and digest */
133 if (!OBJ_find_sigid_algs(eckdf_nid, &kdfmd_nid, &kdf_nid))
134 return 0;
135
136 if (kdf_nid == NID_dh_std_kdf)
137 cofactor = 0;
138 else if (kdf_nid == NID_dh_cofactor_kdf)
139 cofactor = 1;
140 else
141 return 0;
142
143 if (EVP_PKEY_CTX_set_ecdh_cofactor_mode(pctx, cofactor) <= 0)
144 return 0;
145
146 if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, EVP_PKEY_ECDH_KDF_X9_63) <= 0)
147 return 0;
148
149 kdf_md = EVP_get_digestbynid(kdfmd_nid);
150 if (!kdf_md)
151 return 0;
152
153 if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
154 return 0;
155 return 1;
156 }
157
ecdh_cms_set_shared_info(EVP_PKEY_CTX * pctx,CMS_RecipientInfo * ri)158 static int ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
159 {
160 int rv = 0;
161 X509_ALGOR *alg, *kekalg = NULL;
162 ASN1_OCTET_STRING *ukm;
163 const unsigned char *p;
164 unsigned char *der = NULL;
165 int plen, keylen;
166 EVP_CIPHER *kekcipher = NULL;
167 EVP_CIPHER_CTX *kekctx;
168 char name[OSSL_MAX_NAME_SIZE];
169
170 if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
171 return 0;
172
173 if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) {
174 ERR_raise(ERR_LIB_CMS, CMS_R_KDF_PARAMETER_ERROR);
175 return 0;
176 }
177
178 if (alg->parameter->type != V_ASN1_SEQUENCE)
179 return 0;
180
181 p = alg->parameter->value.sequence->data;
182 plen = alg->parameter->value.sequence->length;
183 kekalg = d2i_X509_ALGOR(NULL, &p, plen);
184 if (kekalg == NULL)
185 goto err;
186 kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
187 if (kekctx == NULL)
188 goto err;
189 OBJ_obj2txt(name, sizeof(name), kekalg->algorithm, 0);
190 kekcipher = EVP_CIPHER_fetch(pctx->libctx, name, pctx->propquery);
191 if (kekcipher == NULL || EVP_CIPHER_get_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
192 goto err;
193 if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
194 goto err;
195 if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
196 goto err;
197
198 keylen = EVP_CIPHER_CTX_get_key_length(kekctx);
199 if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
200 goto err;
201
202 plen = CMS_SharedInfo_encode(&der, kekalg, ukm, keylen);
203
204 if (plen <= 0)
205 goto err;
206
207 if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
208 goto err;
209 der = NULL;
210
211 rv = 1;
212 err:
213 EVP_CIPHER_free(kekcipher);
214 X509_ALGOR_free(kekalg);
215 OPENSSL_free(der);
216 return rv;
217 }
218
ecdh_cms_decrypt(CMS_RecipientInfo * ri)219 static int ecdh_cms_decrypt(CMS_RecipientInfo *ri)
220 {
221 EVP_PKEY_CTX *pctx;
222
223 pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
224 if (pctx == NULL)
225 return 0;
226 /* See if we need to set peer key */
227 if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
228 X509_ALGOR *alg;
229 ASN1_BIT_STRING *pubkey;
230
231 if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
232 NULL, NULL, NULL))
233 return 0;
234 if (alg == NULL || pubkey == NULL)
235 return 0;
236 if (!ecdh_cms_set_peerkey(pctx, alg, pubkey)) {
237 ERR_raise(ERR_LIB_CMS, CMS_R_PEER_KEY_ERROR);
238 return 0;
239 }
240 }
241 /* Set ECDH derivation parameters and initialise unwrap context */
242 if (!ecdh_cms_set_shared_info(pctx, ri)) {
243 ERR_raise(ERR_LIB_CMS, CMS_R_SHARED_INFO_ERROR);
244 return 0;
245 }
246 return 1;
247 }
248
ecdh_cms_encrypt(CMS_RecipientInfo * ri)249 static int ecdh_cms_encrypt(CMS_RecipientInfo *ri)
250 {
251 EVP_PKEY_CTX *pctx;
252 EVP_PKEY *pkey;
253 EVP_CIPHER_CTX *ctx;
254 int keylen;
255 X509_ALGOR *talg, *wrap_alg = NULL;
256 const ASN1_OBJECT *aoid;
257 ASN1_BIT_STRING *pubkey;
258 ASN1_STRING *wrap_str;
259 ASN1_OCTET_STRING *ukm;
260 unsigned char *penc = NULL;
261 int penclen;
262 int rv = 0;
263 int ecdh_nid, kdf_type, kdf_nid, wrap_nid;
264 const EVP_MD *kdf_md;
265
266 pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
267 if (pctx == NULL)
268 return 0;
269 /* Get ephemeral key */
270 pkey = EVP_PKEY_CTX_get0_pkey(pctx);
271 if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
272 NULL, NULL, NULL))
273 goto err;
274 X509_ALGOR_get0(&aoid, NULL, NULL, talg);
275 /* Is everything uninitialised? */
276 if (aoid == OBJ_nid2obj(NID_undef)) {
277 /* Set the key */
278 size_t enckeylen;
279
280 enckeylen = EVP_PKEY_get1_encoded_public_key(pkey, &penc);
281 if (enckeylen > INT_MAX || enckeylen == 0)
282 goto err;
283 ASN1_STRING_set0(pubkey, penc, (int)enckeylen);
284 pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
285 pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
286
287 penc = NULL;
288 (void)X509_ALGOR_set0(talg, OBJ_nid2obj(NID_X9_62_id_ecPublicKey),
289 V_ASN1_UNDEF, NULL); /* cannot fail */
290 }
291
292 /* See if custom parameters set */
293 kdf_type = EVP_PKEY_CTX_get_ecdh_kdf_type(pctx);
294 if (kdf_type <= 0)
295 goto err;
296 if (EVP_PKEY_CTX_get_ecdh_kdf_md(pctx, &kdf_md) <= 0)
297 goto err;
298 ecdh_nid = EVP_PKEY_CTX_get_ecdh_cofactor_mode(pctx);
299 if (ecdh_nid < 0)
300 goto err;
301 else if (ecdh_nid == 0)
302 ecdh_nid = NID_dh_std_kdf;
303 else if (ecdh_nid == 1)
304 ecdh_nid = NID_dh_cofactor_kdf;
305
306 if (kdf_type == EVP_PKEY_ECDH_KDF_NONE) {
307 kdf_type = EVP_PKEY_ECDH_KDF_X9_63;
308 if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, kdf_type) <= 0)
309 goto err;
310 } else
311 /* Unknown KDF */
312 goto err;
313 if (kdf_md == NULL) {
314 /* Fixme later for better MD */
315 kdf_md = EVP_sha1();
316 if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
317 goto err;
318 }
319
320 if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
321 goto err;
322
323 /* Lookup NID for KDF+cofactor+digest */
324
325 if (!OBJ_find_sigid_by_algs(&kdf_nid, EVP_MD_get_type(kdf_md), ecdh_nid))
326 goto err;
327 /* Get wrap NID */
328 ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
329 wrap_nid = EVP_CIPHER_CTX_get_type(ctx);
330 keylen = EVP_CIPHER_CTX_get_key_length(ctx);
331
332 /* Package wrap algorithm in an AlgorithmIdentifier */
333
334 wrap_alg = X509_ALGOR_new();
335 if (wrap_alg == NULL)
336 goto err;
337 wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
338 wrap_alg->parameter = ASN1_TYPE_new();
339 if (wrap_alg->parameter == NULL)
340 goto err;
341 if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
342 goto err;
343 if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
344 ASN1_TYPE_free(wrap_alg->parameter);
345 wrap_alg->parameter = NULL;
346 }
347
348 if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
349 goto err;
350
351 penclen = CMS_SharedInfo_encode(&penc, wrap_alg, ukm, keylen);
352
353 if (penclen <= 0)
354 goto err;
355
356 if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, penc, penclen) <= 0)
357 goto err;
358 penc = NULL;
359
360 /*
361 * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
362 * of another AlgorithmIdentifier.
363 */
364 penclen = i2d_X509_ALGOR(wrap_alg, &penc);
365 if (penclen <= 0)
366 goto err;
367 wrap_str = ASN1_STRING_new();
368 if (wrap_str == NULL)
369 goto err;
370 ASN1_STRING_set0(wrap_str, penc, penclen);
371 penc = NULL;
372 X509_ALGOR_set0(talg, OBJ_nid2obj(kdf_nid), V_ASN1_SEQUENCE, wrap_str);
373
374 rv = 1;
375
376 err:
377 OPENSSL_free(penc);
378 X509_ALGOR_free(wrap_alg);
379 return rv;
380 }
381
ossl_cms_ecdh_envelope(CMS_RecipientInfo * ri,int decrypt)382 int ossl_cms_ecdh_envelope(CMS_RecipientInfo *ri, int decrypt)
383 {
384 assert(decrypt == 0 || decrypt == 1);
385
386 if (decrypt == 1)
387 return ecdh_cms_decrypt(ri);
388
389 if (decrypt == 0)
390 return ecdh_cms_encrypt(ri);
391
392 ERR_raise(ERR_LIB_CMS, CMS_R_NOT_SUPPORTED_FOR_THIS_KEY_TYPE);
393 return 0;
394 }
395
396 /* ECDSA and DSA implementation is the same */
ossl_cms_ecdsa_dsa_sign(CMS_SignerInfo * si,int verify)397 int ossl_cms_ecdsa_dsa_sign(CMS_SignerInfo *si, int verify)
398 {
399 assert(verify == 0 || verify == 1);
400
401 if (verify == 0) {
402 int snid, hnid;
403 X509_ALGOR *alg1, *alg2;
404 EVP_PKEY *pkey = si->pkey;
405
406 CMS_SignerInfo_get0_algs(si, NULL, NULL, &alg1, &alg2);
407 if (alg1 == NULL || alg1->algorithm == NULL)
408 return -1;
409 hnid = OBJ_obj2nid(alg1->algorithm);
410 if (hnid == NID_undef)
411 return -1;
412 if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_get_id(pkey)))
413 return -1;
414 X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
415 }
416 return 1;
417 }
418