1/*
2 * Copyright 2019 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 <openssl/crypto.h>
11#include <openssl/evp.h>
12#include <openssl/err.h>
13#include "internal/refcount.h"
14#include "crypto/evp.h"
15#include "internal/provider.h"
16#include "internal/numbers.h" /* includes SIZE_MAX */
17#include "evp_local.h"
18
19static EVP_KEYEXCH *evp_keyexch_new(OSSL_PROVIDER *prov)
20{
21 EVP_KEYEXCH *exchange = OPENSSL_zalloc(sizeof(EVP_KEYEXCH));
22
23 if (exchange == NULL) {
24 ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
25 return NULL;
26 }
27
28 exchange->lock = CRYPTO_THREAD_lock_new();
29 if (exchange->lock == NULL) {
30 ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
31 OPENSSL_free(exchange);
32 return NULL;
33 }
34 exchange->prov = prov;
35 ossl_provider_up_ref(prov);
36 exchange->refcnt = 1;
37
38 return exchange;
39}
40
41static void *evp_keyexch_from_dispatch(int name_id,
42 const OSSL_DISPATCH *fns,
43 OSSL_PROVIDER *prov)
44{
45 EVP_KEYEXCH *exchange = NULL;
46 int fncnt = 0, paramfncnt = 0;
47
48 if ((exchange = evp_keyexch_new(prov)) == NULL) {
49 ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
50 goto err;
51 }
52
53 exchange->name_id = name_id;
54
55 for (; fns->function_id != 0; fns++) {
56 switch (fns->function_id) {
57 case OSSL_FUNC_KEYEXCH_NEWCTX:
58 if (exchange->newctx != NULL)
59 break;
60 exchange->newctx = OSSL_get_OP_keyexch_newctx(fns);
61 fncnt++;
62 break;
63 case OSSL_FUNC_KEYEXCH_INIT:
64 if (exchange->init != NULL)
65 break;
66 exchange->init = OSSL_get_OP_keyexch_init(fns);
67 fncnt++;
68 break;
69 case OSSL_FUNC_KEYEXCH_SET_PEER:
70 if (exchange->set_peer != NULL)
71 break;
72 exchange->set_peer = OSSL_get_OP_keyexch_set_peer(fns);
73 break;
74 case OSSL_FUNC_KEYEXCH_DERIVE:
75 if (exchange->derive != NULL)
76 break;
77 exchange->derive = OSSL_get_OP_keyexch_derive(fns);
78 fncnt++;
79 break;
80 case OSSL_FUNC_KEYEXCH_FREECTX:
81 if (exchange->freectx != NULL)
82 break;
83 exchange->freectx = OSSL_get_OP_keyexch_freectx(fns);
84 fncnt++;
85 break;
86 case OSSL_FUNC_KEYEXCH_DUPCTX:
87 if (exchange->dupctx != NULL)
88 break;
89 exchange->dupctx = OSSL_get_OP_keyexch_dupctx(fns);
90 break;
91 case OSSL_FUNC_KEYEXCH_SET_CTX_PARAMS:
92 if (exchange->set_ctx_params != NULL)
93 break;
94 exchange->set_ctx_params = OSSL_get_OP_keyexch_set_ctx_params(fns);
95 paramfncnt++;
96 break;
97 case OSSL_FUNC_KEYEXCH_SETTABLE_CTX_PARAMS:
98 if (exchange->settable_ctx_params != NULL)
99 break;
100 exchange->settable_ctx_params
101 = OSSL_get_OP_keyexch_settable_ctx_params(fns);
102 paramfncnt++;
103 break;
104 }
105 }
106 if (fncnt != 4 || (paramfncnt != 0 && paramfncnt != 2)) {
107 /*
108 * In order to be a consistent set of functions we must have at least
109 * a complete set of "exchange" functions: init, derive, newctx,
110 * and freectx. The set_ctx_params and settable_ctx_params functions are
111 * optional, but if one of them is present then the other one must also
112 * be present. The dupctx and set_peer functions are optional.
113 */
114 EVPerr(EVP_F_EVP_KEYEXCH_FROM_DISPATCH,
115 EVP_R_INVALID_PROVIDER_FUNCTIONS);
116 goto err;
117 }
118
119 return exchange;
120
121 err:
122 EVP_KEYEXCH_free(exchange);
123 return NULL;
124}
125
126void EVP_KEYEXCH_free(EVP_KEYEXCH *exchange)
127{
128 if (exchange != NULL) {
129 int i;
130
131 CRYPTO_DOWN_REF(&exchange->refcnt, &i, exchange->lock);
132 if (i > 0)
133 return;
134 ossl_provider_free(exchange->prov);
135 CRYPTO_THREAD_lock_free(exchange->lock);
136 OPENSSL_free(exchange);
137 }
138}
139
140int EVP_KEYEXCH_up_ref(EVP_KEYEXCH *exchange)
141{
142 int ref = 0;
143
144 CRYPTO_UP_REF(&exchange->refcnt, &ref, exchange->lock);
145 return 1;
146}
147
148OSSL_PROVIDER *EVP_KEYEXCH_provider(const EVP_KEYEXCH *exchange)
149{
150 return exchange->prov;
151}
152
153EVP_KEYEXCH *EVP_KEYEXCH_fetch(OPENSSL_CTX *ctx, const char *algorithm,
154 const char *properties)
155{
156 return evp_generic_fetch(ctx, OSSL_OP_KEYEXCH, algorithm, properties,
157 evp_keyexch_from_dispatch,
158 (int (*)(void *))EVP_KEYEXCH_up_ref,
159 (void (*)(void *))EVP_KEYEXCH_free);
160}
161
162int EVP_PKEY_derive_init(EVP_PKEY_CTX *ctx)
163{
164 int ret;
165 void *provkey = NULL;
166 EVP_KEYEXCH *exchange = NULL;
167
168 if (ctx == NULL) {
169 EVPerr(0, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
170 return -2;
171 }
172
173 evp_pkey_ctx_free_old_ops(ctx);
174 ctx->operation = EVP_PKEY_OP_DERIVE;
175
176 if (ctx->engine != NULL || ctx->algorithm == NULL)
177 goto legacy;
178
179 /*
180 * Because we cleared out old ops, we shouldn't need to worry about
181 * checking if exchange is already there. Keymgmt is a different
182 * matter, as it isn't tied to a specific EVP_PKEY op.
183 */
184 exchange = EVP_KEYEXCH_fetch(ctx->libctx, ctx->algorithm, ctx->propquery);
185 if (exchange != NULL && ctx->keymgmt == NULL) {
186 int name_id = EVP_KEYEXCH_number(exchange);
187
188 ctx->keymgmt =
189 evp_keymgmt_fetch_by_number(ctx->libctx, name_id, ctx->propquery);
190 }
191
192 if (ctx->keymgmt == NULL
193 || exchange == NULL
194 || (EVP_KEYMGMT_provider(ctx->keymgmt)
195 != EVP_KEYEXCH_provider(exchange))) {
196 /*
197 * We don't have the full support we need with provided methods,
198 * let's go see if legacy does. Also, we don't need to free
199 * ctx->keymgmt here, as it's not necessarily tied to this
200 * operation. It will be freed by EVP_PKEY_CTX_free().
201 */
202 EVP_KEYEXCH_free(exchange);
203 goto legacy;
204 }
205
206
207 ctx->op.kex.exchange = exchange;
208
209 if (ctx->pkey != NULL) {
210 provkey = evp_keymgmt_export_to_provider(ctx->pkey, ctx->keymgmt, 0);
211 if (provkey == NULL) {
212 EVPerr(0, EVP_R_INITIALIZATION_ERROR);
213 goto err;
214 }
215 }
216 ctx->op.kex.exchprovctx = exchange->newctx(ossl_provider_ctx(exchange->prov));
217 if (ctx->op.kex.exchprovctx == NULL) {
218 /* The provider key can stay in the cache */
219 EVPerr(0, EVP_R_INITIALIZATION_ERROR);
220 goto err;
221 }
222 ret = exchange->init(ctx->op.kex.exchprovctx, provkey);
223
224 return ret ? 1 : 0;
225 err:
226 ctx->operation = EVP_PKEY_OP_UNDEFINED;
227 return 0;
228
229 legacy:
230 if (ctx == NULL || ctx->pmeth == NULL || ctx->pmeth->derive == NULL) {
231 EVPerr(0, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
232 return -2;
233 }
234
235 if (ctx->pmeth->derive_init == NULL)
236 return 1;
237 ret = ctx->pmeth->derive_init(ctx);
238 if (ret <= 0)
239 ctx->operation = EVP_PKEY_OP_UNDEFINED;
240 return ret;
241}
242
243int EVP_PKEY_derive_set_peer(EVP_PKEY_CTX *ctx, EVP_PKEY *peer)
244{
245 int ret;
246 void *provkey = NULL;
247
248 if (ctx == NULL) {
249 EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER,
250 EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
251 return -2;
252 }
253
254 if (!EVP_PKEY_CTX_IS_DERIVE_OP(ctx) || ctx->op.kex.exchprovctx == NULL)
255 goto legacy;
256
257 if (ctx->op.kex.exchange->set_peer == NULL) {
258 EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER,
259 EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
260 return -2;
261 }
262
263 provkey = evp_keymgmt_export_to_provider(peer, ctx->keymgmt, 0);
264 if (provkey == NULL) {
265 EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER, ERR_R_INTERNAL_ERROR);
266 return 0;
267 }
268 return ctx->op.kex.exchange->set_peer(ctx->op.kex.exchprovctx, provkey);
269
270 legacy:
271 if (ctx->pmeth == NULL
272 || !(ctx->pmeth->derive != NULL
273 || ctx->pmeth->encrypt != NULL
274 || ctx->pmeth->decrypt != NULL)
275 || ctx->pmeth->ctrl == NULL) {
276 EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER,
277 EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
278 return -2;
279 }
280 if (ctx->operation != EVP_PKEY_OP_DERIVE
281 && ctx->operation != EVP_PKEY_OP_ENCRYPT
282 && ctx->operation != EVP_PKEY_OP_DECRYPT) {
283 EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER,
284 EVP_R_OPERATON_NOT_INITIALIZED);
285 return -1;
286 }
287
288 ret = ctx->pmeth->ctrl(ctx, EVP_PKEY_CTRL_PEER_KEY, 0, peer);
289
290 if (ret <= 0)
291 return ret;
292
293 if (ret == 2)
294 return 1;
295
296 if (ctx->pkey == NULL) {
297 EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER, EVP_R_NO_KEY_SET);
298 return -1;
299 }
300
301 if (ctx->pkey->type != peer->type) {
302 EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER, EVP_R_DIFFERENT_KEY_TYPES);
303 return -1;
304 }
305
306 /*
307 * For clarity. The error is if parameters in peer are
308 * present (!missing) but don't match. EVP_PKEY_cmp_parameters may return
309 * 1 (match), 0 (don't match) and -2 (comparison is not defined). -1
310 * (different key types) is impossible here because it is checked earlier.
311 * -2 is OK for us here, as well as 1, so we can check for 0 only.
312 */
313 if (!EVP_PKEY_missing_parameters(peer) &&
314 !EVP_PKEY_cmp_parameters(ctx->pkey, peer)) {
315 EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER, EVP_R_DIFFERENT_PARAMETERS);
316 return -1;
317 }
318
319 EVP_PKEY_free(ctx->peerkey);
320 ctx->peerkey = peer;
321
322 ret = ctx->pmeth->ctrl(ctx, EVP_PKEY_CTRL_PEER_KEY, 1, peer);
323
324 if (ret <= 0) {
325 ctx->peerkey = NULL;
326 return ret;
327 }
328
329 EVP_PKEY_up_ref(peer);
330 return 1;
331}
332
333int EVP_PKEY_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *pkeylen)
334{
335 int ret;
336
337 if (ctx == NULL) {
338 EVPerr(EVP_F_EVP_PKEY_DERIVE,
339 EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
340 return -2;
341 }
342
343 if (!EVP_PKEY_CTX_IS_DERIVE_OP(ctx)) {
344 EVPerr(EVP_F_EVP_PKEY_DERIVE, EVP_R_OPERATON_NOT_INITIALIZED);
345 return -1;
346 }
347
348 if (ctx->op.kex.exchprovctx == NULL)
349 goto legacy;
350
351 ret = ctx->op.kex.exchange->derive(ctx->op.kex.exchprovctx, key, pkeylen,
352 SIZE_MAX);
353
354 return ret;
355 legacy:
356 if (ctx == NULL || ctx->pmeth == NULL || ctx->pmeth->derive == NULL) {
357 EVPerr(EVP_F_EVP_PKEY_DERIVE,
358 EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
359 return -2;
360 }
361
362 M_check_autoarg(ctx, key, pkeylen, EVP_F_EVP_PKEY_DERIVE)
363 return ctx->pmeth->derive(ctx, key, pkeylen);
364}
365
366int EVP_KEYEXCH_number(const EVP_KEYEXCH *keyexch)
367{
368 return keyexch->name_id;
369}
370
371int EVP_KEYEXCH_is_a(const EVP_KEYEXCH *keyexch, const char *name)
372{
373 return evp_is_a(keyexch->prov, keyexch->name_id, name);
374}
375
376void EVP_KEYEXCH_do_all_provided(OPENSSL_CTX *libctx,
377 void (*fn)(EVP_KEYEXCH *keyexch, void *arg),
378 void *arg)
379{
380 evp_generic_do_all(libctx, OSSL_OP_KEYEXCH,
381 (void (*)(void *, void *))fn, arg,
382 evp_keyexch_from_dispatch,
383 (void (*)(void *))EVP_KEYEXCH_free);
384}
385
386void EVP_KEYEXCH_names_do_all(const EVP_KEYEXCH *keyexch,
387 void (*fn)(const char *name, void *data),
388 void *data)
389{
390 if (keyexch->prov != NULL)
391 evp_names_do_all(keyexch->prov, keyexch->name_id, fn, data);
392}
393