c43fe455a8046edfdf1153b3cded26083f5345f3
[strongswan.git] / src / libstrongswan / plugins / openssl / openssl_ec_diffie_hellman.c
1 /*
2 * Copyright (C) 2008-2013 Tobias Brunner
3 * Hochschule fuer Technik Rapperswil
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
12 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * for more details.
14 */
15
16 #include <openssl/opensslconf.h>
17
18 #ifndef OPENSSL_NO_EC
19
20 #include <openssl/ec.h>
21 #include <openssl/objects.h>
22 #include <openssl/bn.h>
23
24 #include "openssl_ec_diffie_hellman.h"
25 #include "openssl_util.h"
26
27 #include <utils/debug.h>
28
29 typedef struct private_openssl_ec_diffie_hellman_t private_openssl_ec_diffie_hellman_t;
30
31 /**
32 * Private data of an openssl_ec_diffie_hellman_t object.
33 */
34 struct private_openssl_ec_diffie_hellman_t {
35 /**
36 * Public openssl_ec_diffie_hellman_t interface.
37 */
38 openssl_ec_diffie_hellman_t public;
39
40 /**
41 * Diffie Hellman group number.
42 */
43 u_int16_t group;
44
45 /**
46 * EC private (public) key
47 */
48 EC_KEY *key;
49
50 /**
51 * EC group
52 */
53 const EC_GROUP *ec_group;
54
55 /**
56 * Other public key
57 */
58 EC_POINT *pub_key;
59
60 /**
61 * Shared secret
62 */
63 chunk_t shared_secret;
64
65 /**
66 * True if shared secret is computed
67 */
68 bool computed;
69 };
70
71 /**
72 * Convert a chunk to an EC_POINT (which must already exist). The x and y
73 * coordinates of the point have to be concatenated in the chunk.
74 */
75 static bool chunk2ecp(const EC_GROUP *group, chunk_t chunk, EC_POINT *point)
76 {
77 BN_CTX *ctx;
78 BIGNUM *x, *y;
79 bool ret = FALSE;
80
81 ctx = BN_CTX_new();
82 if (!ctx)
83 {
84 return FALSE;
85 }
86
87 BN_CTX_start(ctx);
88 x = BN_CTX_get(ctx);
89 y = BN_CTX_get(ctx);
90 if (!x || !y)
91 {
92 goto error;
93 }
94
95 if (!openssl_bn_split(chunk, x, y))
96 {
97 goto error;
98 }
99
100 if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx))
101 {
102 goto error;
103 }
104
105 ret = TRUE;
106 error:
107 BN_CTX_end(ctx);
108 BN_CTX_free(ctx);
109 return ret;
110 }
111
112 /**
113 * Convert an EC_POINT to a chunk by concatenating the x and y coordinates of
114 * the point. This function allocates memory for the chunk.
115 */
116 static bool ecp2chunk(const EC_GROUP *group, const EC_POINT *point,
117 chunk_t *chunk, bool x_coordinate_only)
118 {
119 BN_CTX *ctx;
120 BIGNUM *x, *y;
121 bool ret = FALSE;
122
123 ctx = BN_CTX_new();
124 if (!ctx)
125 {
126 return FALSE;
127 }
128
129 BN_CTX_start(ctx);
130 x = BN_CTX_get(ctx);
131 y = BN_CTX_get(ctx);
132 if (!x || !y)
133 {
134 goto error;
135 }
136
137 if (!EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx))
138 {
139 goto error;
140 }
141
142 if (x_coordinate_only)
143 {
144 y = NULL;
145 }
146 if (!openssl_bn_cat(EC_FIELD_ELEMENT_LEN(group), x, y, chunk))
147 {
148 goto error;
149 }
150
151 ret = TRUE;
152 error:
153 BN_CTX_end(ctx);
154 BN_CTX_free(ctx);
155 return ret;
156 }
157
158 /**
159 * Compute the shared secret.
160 *
161 * We cannot use the function ECDH_compute_key() because that returns only the
162 * x coordinate of the shared secret point (which is defined, for instance, in
163 * 'NIST SP 800-56A').
164 * However, we need both coordinates as RFC 4753 says: "The Diffie-Hellman
165 * public value is obtained by concatenating the x and y values. The format
166 * of the Diffie-Hellman shared secret value is the same as that of the
167 * Diffie-Hellman public value."
168 */
169 static bool compute_shared_key(private_openssl_ec_diffie_hellman_t *this,
170 chunk_t *shared_secret)
171 {
172 const BIGNUM *priv_key;
173 EC_POINT *secret = NULL;
174 bool x_coordinate_only, ret = FALSE;
175
176 priv_key = EC_KEY_get0_private_key(this->key);
177 if (!priv_key)
178 {
179 goto error;
180 }
181
182 secret = EC_POINT_new(this->ec_group);
183 if (!secret)
184 {
185 goto error;
186 }
187
188 if (!EC_POINT_mul(this->ec_group, secret, NULL, this->pub_key, priv_key, NULL))
189 {
190 goto error;
191 }
192
193 /*
194 * The default setting ecp_x_coordinate_only = TRUE
195 * applies the following errata for RFC 4753:
196 * http://www.rfc-editor.org/errata_search.php?eid=9
197 */
198 x_coordinate_only = lib->settings->get_bool(lib->settings,
199 "libstrongswan.ecp_x_coordinate_only", TRUE);
200 if (!ecp2chunk(this->ec_group, secret, shared_secret, x_coordinate_only))
201 {
202 goto error;
203 }
204
205 ret = TRUE;
206 error:
207 if (secret)
208 {
209 EC_POINT_clear_free(secret);
210 }
211 return ret;
212 }
213
214 METHOD(diffie_hellman_t, set_other_public_value, void,
215 private_openssl_ec_diffie_hellman_t *this, chunk_t value)
216 {
217 if (!chunk2ecp(this->ec_group, value, this->pub_key))
218 {
219 DBG1(DBG_LIB, "ECDH public value is malformed");
220 return;
221 }
222
223 chunk_clear(&this->shared_secret);
224
225 if (!compute_shared_key(this, &this->shared_secret)) {
226 DBG1(DBG_LIB, "ECDH shared secret computation failed");
227 return;
228 }
229
230 this->computed = TRUE;
231 }
232
233 METHOD(diffie_hellman_t, get_my_public_value, void,
234 private_openssl_ec_diffie_hellman_t *this,chunk_t *value)
235 {
236 ecp2chunk(this->ec_group, EC_KEY_get0_public_key(this->key), value, FALSE);
237 }
238
239 METHOD(diffie_hellman_t, get_shared_secret, status_t,
240 private_openssl_ec_diffie_hellman_t *this, chunk_t *secret)
241 {
242 if (!this->computed)
243 {
244 return FAILED;
245 }
246 *secret = chunk_clone(this->shared_secret);
247 return SUCCESS;
248 }
249
250 METHOD(diffie_hellman_t, get_dh_group, diffie_hellman_group_t,
251 private_openssl_ec_diffie_hellman_t *this)
252 {
253 return this->group;
254 }
255
256 METHOD(diffie_hellman_t, destroy, void,
257 private_openssl_ec_diffie_hellman_t *this)
258 {
259 if (this->pub_key)
260 {
261 EC_POINT_clear_free(this->pub_key);
262 }
263 if (this->key)
264 {
265 EC_KEY_free(this->key);
266 }
267 chunk_clear(&this->shared_secret);
268 free(this);
269 }
270
271 /**
272 * ECC Brainpool curves are not available in OpenSSL releases < 1.0.2, but we
273 * don't check the version in case somebody backported them.
274 */
275 #if (!defined(NID_brainpoolP224r1) || !defined(NID_brainpoolP256r1) || \
276 !defined(NID_brainpoolP384r1) || !defined(NID_brainpoolP512r1))
277
278 /**
279 * Parameters for ECC Brainpool curves
280 */
281 typedef struct {
282 /** DH group */
283 diffie_hellman_group_t group;
284
285 /** The prime p specifying the base field */
286 const chunk_t p;
287
288 /** Coefficient a of the elliptic curve E: y^2 = x^3 + ax + b (mod p) */
289 const chunk_t a;
290
291 /** Coefficient b */
292 const chunk_t b;
293
294 /** x coordinate of base point G (a point in E of prime order) */
295 const chunk_t x;
296
297 /** y coordinate of base point G */
298 const chunk_t y;
299
300 /** Prime order q of the group generated by G */
301 const chunk_t q;
302
303 } bp_curve;
304
305 /**
306 * List of ECC Brainpool curves
307 */
308 static bp_curve bp_curves[] = {
309 {
310 /* ECC Brainpool 224-bit curve (RFC 5639), brainpoolP224r1 */
311 .group = ECP_224_BP,
312 .p = chunk_from_chars(
313 0xD7,0xC1,0x34,0xAA,0x26,0x43,0x66,0x86,0x2A,0x18,0x30,0x25,0x75,0xD1,0xD7,0x87,
314 0xB0,0x9F,0x07,0x57,0x97,0xDA,0x89,0xF5,0x7E,0xC8,0xC0,0xFF),
315 .a = chunk_from_chars(
316 0x68,0xA5,0xE6,0x2C,0xA9,0xCE,0x6C,0x1C,0x29,0x98,0x03,0xA6,0xC1,0x53,0x0B,0x51,
317 0x4E,0x18,0x2A,0xD8,0xB0,0x04,0x2A,0x59,0xCA,0xD2,0x9F,0x43),
318 .b = chunk_from_chars(
319 0x25,0x80,0xF6,0x3C,0xCF,0xE4,0x41,0x38,0x87,0x07,0x13,0xB1,0xA9,0x23,0x69,0xE3,
320 0x3E,0x21,0x35,0xD2,0x66,0xDB,0xB3,0x72,0x38,0x6C,0x40,0x0B),
321 .x = chunk_from_chars(
322 0x0D,0x90,0x29,0xAD,0x2C,0x7E,0x5C,0xF4,0x34,0x08,0x23,0xB2,0xA8,0x7D,0xC6,0x8C,
323 0x9E,0x4C,0xE3,0x17,0x4C,0x1E,0x6E,0xFD,0xEE,0x12,0xC0,0x7D),
324 .y = chunk_from_chars(
325 0x58,0xAA,0x56,0xF7,0x72,0xC0,0x72,0x6F,0x24,0xC6,0xB8,0x9E,0x4E,0xCD,0xAC,0x24,
326 0x35,0x4B,0x9E,0x99,0xCA,0xA3,0xF6,0xD3,0x76,0x14,0x02,0xCD),
327 .q = chunk_from_chars(
328 0xD7,0xC1,0x34,0xAA,0x26,0x43,0x66,0x86,0x2A,0x18,0x30,0x25,0x75,0xD0,0xFB,0x98,
329 0xD1,0x16,0xBC,0x4B,0x6D,0xDE,0xBC,0xA3,0xA5,0xA7,0x93,0x9F),
330 },
331 {
332 /* ECC Brainpool 256-bit curve (RFC 5639), brainpoolP256r1 */
333 .group = ECP_256_BP,
334 .p = chunk_from_chars(
335 0xA9,0xFB,0x57,0xDB,0xA1,0xEE,0xA9,0xBC,0x3E,0x66,0x0A,0x90,0x9D,0x83,0x8D,0x72,
336 0x6E,0x3B,0xF6,0x23,0xD5,0x26,0x20,0x28,0x20,0x13,0x48,0x1D,0x1F,0x6E,0x53,0x77),
337 .a = chunk_from_chars(
338 0x7D,0x5A,0x09,0x75,0xFC,0x2C,0x30,0x57,0xEE,0xF6,0x75,0x30,0x41,0x7A,0xFF,0xE7,
339 0xFB,0x80,0x55,0xC1,0x26,0xDC,0x5C,0x6C,0xE9,0x4A,0x4B,0x44,0xF3,0x30,0xB5,0xD9),
340 .b = chunk_from_chars(
341 0x26,0xDC,0x5C,0x6C,0xE9,0x4A,0x4B,0x44,0xF3,0x30,0xB5,0xD9,0xBB,0xD7,0x7C,0xBF,
342 0x95,0x84,0x16,0x29,0x5C,0xF7,0xE1,0xCE,0x6B,0xCC,0xDC,0x18,0xFF,0x8C,0x07,0xB6),
343 .x = chunk_from_chars(
344 0x8B,0xD2,0xAE,0xB9,0xCB,0x7E,0x57,0xCB,0x2C,0x4B,0x48,0x2F,0xFC,0x81,0xB7,0xAF,
345 0xB9,0xDE,0x27,0xE1,0xE3,0xBD,0x23,0xC2,0x3A,0x44,0x53,0xBD,0x9A,0xCE,0x32,0x62),
346 .y = chunk_from_chars(
347 0x54,0x7E,0xF8,0x35,0xC3,0xDA,0xC4,0xFD,0x97,0xF8,0x46,0x1A,0x14,0x61,0x1D,0xC9,
348 0xC2,0x77,0x45,0x13,0x2D,0xED,0x8E,0x54,0x5C,0x1D,0x54,0xC7,0x2F,0x04,0x69,0x97),
349 .q = chunk_from_chars(
350 0xA9,0xFB,0x57,0xDB,0xA1,0xEE,0xA9,0xBC,0x3E,0x66,0x0A,0x90,0x9D,0x83,0x8D,0x71,
351 0x8C,0x39,0x7A,0xA3,0xB5,0x61,0xA6,0xF7,0x90,0x1E,0x0E,0x82,0x97,0x48,0x56,0xA7),
352 },
353 {
354 /* ECC Brainpool 384-bit curve (RFC 5639), brainpoolP384r1 */
355 .group = ECP_384_BP,
356 .p = chunk_from_chars(
357 0x8C,0xB9,0x1E,0x82,0xA3,0x38,0x6D,0x28,0x0F,0x5D,0x6F,0x7E,0x50,0xE6,0x41,0xDF,
358 0x15,0x2F,0x71,0x09,0xED,0x54,0x56,0xB4,0x12,0xB1,0xDA,0x19,0x7F,0xB7,0x11,0x23,
359 0xAC,0xD3,0xA7,0x29,0x90,0x1D,0x1A,0x71,0x87,0x47,0x00,0x13,0x31,0x07,0xEC,0x53),
360 .a = chunk_from_chars(
361 0x7B,0xC3,0x82,0xC6,0x3D,0x8C,0x15,0x0C,0x3C,0x72,0x08,0x0A,0xCE,0x05,0xAF,0xA0,
362 0xC2,0xBE,0xA2,0x8E,0x4F,0xB2,0x27,0x87,0x13,0x91,0x65,0xEF,0xBA,0x91,0xF9,0x0F,
363 0x8A,0xA5,0x81,0x4A,0x50,0x3A,0xD4,0xEB,0x04,0xA8,0xC7,0xDD,0x22,0xCE,0x28,0x26),
364 .b = chunk_from_chars(
365 0x04,0xA8,0xC7,0xDD,0x22,0xCE,0x28,0x26,0x8B,0x39,0xB5,0x54,0x16,0xF0,0x44,0x7C,
366 0x2F,0xB7,0x7D,0xE1,0x07,0xDC,0xD2,0xA6,0x2E,0x88,0x0E,0xA5,0x3E,0xEB,0x62,0xD5,
367 0x7C,0xB4,0x39,0x02,0x95,0xDB,0xC9,0x94,0x3A,0xB7,0x86,0x96,0xFA,0x50,0x4C,0x11),
368 .x = chunk_from_chars(
369 0x1D,0x1C,0x64,0xF0,0x68,0xCF,0x45,0xFF,0xA2,0xA6,0x3A,0x81,0xB7,0xC1,0x3F,0x6B,
370 0x88,0x47,0xA3,0xE7,0x7E,0xF1,0x4F,0xE3,0xDB,0x7F,0xCA,0xFE,0x0C,0xBD,0x10,0xE8,
371 0xE8,0x26,0xE0,0x34,0x36,0xD6,0x46,0xAA,0xEF,0x87,0xB2,0xE2,0x47,0xD4,0xAF,0x1E),
372 .y = chunk_from_chars(
373 0x8A,0xBE,0x1D,0x75,0x20,0xF9,0xC2,0xA4,0x5C,0xB1,0xEB,0x8E,0x95,0xCF,0xD5,0x52,
374 0x62,0xB7,0x0B,0x29,0xFE,0xEC,0x58,0x64,0xE1,0x9C,0x05,0x4F,0xF9,0x91,0x29,0x28,
375 0x0E,0x46,0x46,0x21,0x77,0x91,0x81,0x11,0x42,0x82,0x03,0x41,0x26,0x3C,0x53,0x15),
376 .q = chunk_from_chars(
377 0x8C,0xB9,0x1E,0x82,0xA3,0x38,0x6D,0x28,0x0F,0x5D,0x6F,0x7E,0x50,0xE6,0x41,0xDF,
378 0x15,0x2F,0x71,0x09,0xED,0x54,0x56,0xB3,0x1F,0x16,0x6E,0x6C,0xAC,0x04,0x25,0xA7,
379 0xCF,0x3A,0xB6,0xAF,0x6B,0x7F,0xC3,0x10,0x3B,0x88,0x32,0x02,0xE9,0x04,0x65,0x65),
380 },
381 {
382 /* ECC Brainpool 512-bit curve (RFC 5639), brainpoolP512r1 */
383 .group = ECP_512_BP,
384 .p = chunk_from_chars(
385 0xAA,0xDD,0x9D,0xB8,0xDB,0xE9,0xC4,0x8B,0x3F,0xD4,0xE6,0xAE,0x33,0xC9,0xFC,0x07,
386 0xCB,0x30,0x8D,0xB3,0xB3,0xC9,0xD2,0x0E,0xD6,0x63,0x9C,0xCA,0x70,0x33,0x08,0x71,
387 0x7D,0x4D,0x9B,0x00,0x9B,0xC6,0x68,0x42,0xAE,0xCD,0xA1,0x2A,0xE6,0xA3,0x80,0xE6,
388 0x28,0x81,0xFF,0x2F,0x2D,0x82,0xC6,0x85,0x28,0xAA,0x60,0x56,0x58,0x3A,0x48,0xF3),
389 .a = chunk_from_chars(
390 0x78,0x30,0xA3,0x31,0x8B,0x60,0x3B,0x89,0xE2,0x32,0x71,0x45,0xAC,0x23,0x4C,0xC5,
391 0x94,0xCB,0xDD,0x8D,0x3D,0xF9,0x16,0x10,0xA8,0x34,0x41,0xCA,0xEA,0x98,0x63,0xBC,
392 0x2D,0xED,0x5D,0x5A,0xA8,0x25,0x3A,0xA1,0x0A,0x2E,0xF1,0xC9,0x8B,0x9A,0xC8,0xB5,
393 0x7F,0x11,0x17,0xA7,0x2B,0xF2,0xC7,0xB9,0xE7,0xC1,0xAC,0x4D,0x77,0xFC,0x94,0xCA),
394 .b = chunk_from_chars(
395 0x3D,0xF9,0x16,0x10,0xA8,0x34,0x41,0xCA,0xEA,0x98,0x63,0xBC,0x2D,0xED,0x5D,0x5A,
396 0xA8,0x25,0x3A,0xA1,0x0A,0x2E,0xF1,0xC9,0x8B,0x9A,0xC8,0xB5,0x7F,0x11,0x17,0xA7,
397 0x2B,0xF2,0xC7,0xB9,0xE7,0xC1,0xAC,0x4D,0x77,0xFC,0x94,0xCA,0xDC,0x08,0x3E,0x67,
398 0x98,0x40,0x50,0xB7,0x5E,0xBA,0xE5,0xDD,0x28,0x09,0xBD,0x63,0x80,0x16,0xF7,0x23),
399 .x = chunk_from_chars(
400 0x81,0xAE,0xE4,0xBD,0xD8,0x2E,0xD9,0x64,0x5A,0x21,0x32,0x2E,0x9C,0x4C,0x6A,0x93,
401 0x85,0xED,0x9F,0x70,0xB5,0xD9,0x16,0xC1,0xB4,0x3B,0x62,0xEE,0xF4,0xD0,0x09,0x8E,
402 0xFF,0x3B,0x1F,0x78,0xE2,0xD0,0xD4,0x8D,0x50,0xD1,0x68,0x7B,0x93,0xB9,0x7D,0x5F,
403 0x7C,0x6D,0x50,0x47,0x40,0x6A,0x5E,0x68,0x8B,0x35,0x22,0x09,0xBC,0xB9,0xF8,0x22),
404 .y = chunk_from_chars(
405 0x7D,0xDE,0x38,0x5D,0x56,0x63,0x32,0xEC,0xC0,0xEA,0xBF,0xA9,0xCF,0x78,0x22,0xFD,
406 0xF2,0x09,0xF7,0x00,0x24,0xA5,0x7B,0x1A,0xA0,0x00,0xC5,0x5B,0x88,0x1F,0x81,0x11,
407 0xB2,0xDC,0xDE,0x49,0x4A,0x5F,0x48,0x5E,0x5B,0xCA,0x4B,0xD8,0x8A,0x27,0x63,0xAE,
408 0xD1,0xCA,0x2B,0x2F,0xA8,0xF0,0x54,0x06,0x78,0xCD,0x1E,0x0F,0x3A,0xD8,0x08,0x92),
409 .q = chunk_from_chars(
410 0xAA,0xDD,0x9D,0xB8,0xDB,0xE9,0xC4,0x8B,0x3F,0xD4,0xE6,0xAE,0x33,0xC9,0xFC,0x07,
411 0xCB,0x30,0x8D,0xB3,0xB3,0xC9,0xD2,0x0E,0xD6,0x63,0x9C,0xCA,0x70,0x33,0x08,0x70,
412 0x55,0x3E,0x5C,0x41,0x4C,0xA9,0x26,0x19,0x41,0x86,0x61,0x19,0x7F,0xAC,0x10,0x47,
413 0x1D,0xB1,0xD3,0x81,0x08,0x5D,0xDA,0xDD,0xB5,0x87,0x96,0x82,0x9C,0xA9,0x00,0x69),
414 },
415 };
416
417 /**
418 * Create an EC_GROUP object for an ECC Brainpool curve
419 */
420 EC_GROUP *ec_group_new_brainpool(bp_curve *curve)
421 {
422 BIGNUM *p, *a, *b, *x, *y, *q;
423 const BIGNUM *h;
424 EC_POINT *G = NULL;
425 EC_GROUP *group = NULL, *result = NULL;
426 BN_CTX *ctx = NULL;
427
428 ctx = BN_CTX_new();
429 p = BN_bin2bn(curve->p.ptr, curve->p.len, NULL);
430 a = BN_bin2bn(curve->a.ptr, curve->a.len, NULL);
431 b = BN_bin2bn(curve->b.ptr, curve->b.len, NULL);
432 x = BN_bin2bn(curve->x.ptr, curve->x.len, NULL);
433 y = BN_bin2bn(curve->y.ptr, curve->y.len, NULL);
434 q = BN_bin2bn(curve->q.ptr, curve->q.len, NULL);
435 /* all supported groups have a cofactor of 1 */
436 h = BN_value_one();
437 if (!ctx || !p || !a || !b || !x || !y || !q)
438 {
439 goto failed;
440 }
441 group = EC_GROUP_new_curve_GFp(p, a, b, ctx);
442 if (!group)
443 {
444 goto failed;
445 }
446 G = EC_POINT_new(group);
447 if (!G || !EC_POINT_set_affine_coordinates_GFp(group, G, x, y, ctx))
448 {
449 goto failed;
450 }
451 if (!EC_GROUP_set_generator(group, G, q, h))
452 {
453 goto failed;
454 }
455 result = group;
456
457 failed:
458 if (!result && group)
459 {
460 EC_GROUP_free(group);
461 }
462 if (G)
463 {
464 EC_POINT_free(G);
465 }
466 BN_CTX_free(ctx);
467 BN_free(p);
468 BN_free(a);
469 BN_free(b);
470 BN_free(x);
471 BN_free(y);
472 BN_free(q);
473 return result;
474 }
475
476 /**
477 * Create an EC_KEY for ECC Brainpool curves as defined above
478 */
479 static EC_KEY *ec_key_new_brainpool(diffie_hellman_group_t group)
480 {
481 bp_curve *curve = NULL;
482 EC_GROUP *ec_group;
483 EC_KEY *key = NULL;
484 int i;
485
486 for (i = 0; i < countof(bp_curves); i++)
487 {
488 if (bp_curves[i].group == group)
489 {
490 curve = &bp_curves[i];
491 }
492 }
493 if (!curve)
494 {
495 return NULL;
496 }
497 ec_group = ec_group_new_brainpool(curve);
498 if (!ec_group)
499 {
500 return NULL;
501 }
502 key = EC_KEY_new();
503 if (!key || !EC_KEY_set_group(key, ec_group))
504 {
505 EC_KEY_free(key);
506 key = NULL;
507 }
508 EC_GROUP_free(ec_group);
509 return key;
510 }
511
512 #else /* !NID_brainpoolP224r1 || ... */
513
514 /**
515 * Create an EC_KEY for ECC Brainpool curves as defined by OpenSSL
516 */
517 static EC_KEY *ec_key_new_brainpool(diffie_hellman_group_t group)
518 {
519 switch (group)
520 {
521 case ECP_224_BP:
522 return EC_KEY_new_by_curve_name(NID_brainpoolP224r1);
523 case ECP_256_BP:
524 return EC_KEY_new_by_curve_name(NID_brainpoolP256r1);
525 case ECP_384_BP:
526 return EC_KEY_new_by_curve_name(NID_brainpoolP384r1);
527 case ECP_512_BP:
528 return EC_KEY_new_by_curve_name(NID_brainpoolP512r1);
529 default:
530 return NULL;
531 }
532 }
533
534 #endif /* !NID_brainpoolP224r1 || ... */
535
536 /*
537 * Described in header.
538 */
539 openssl_ec_diffie_hellman_t *openssl_ec_diffie_hellman_create(diffie_hellman_group_t group)
540 {
541 private_openssl_ec_diffie_hellman_t *this;
542
543 INIT(this,
544 .public = {
545 .dh = {
546 .get_shared_secret = _get_shared_secret,
547 .set_other_public_value = _set_other_public_value,
548 .get_my_public_value = _get_my_public_value,
549 .get_dh_group = _get_dh_group,
550 .destroy = _destroy,
551 },
552 },
553 .group = group,
554 );
555
556 switch (group)
557 {
558 case ECP_192_BIT:
559 this->key = EC_KEY_new_by_curve_name(NID_X9_62_prime192v1);
560 break;
561 case ECP_224_BIT:
562 this->key = EC_KEY_new_by_curve_name(NID_secp224r1);
563 break;
564 case ECP_256_BIT:
565 this->key = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
566 break;
567 case ECP_384_BIT:
568 this->key = EC_KEY_new_by_curve_name(NID_secp384r1);
569 break;
570 case ECP_521_BIT:
571 this->key = EC_KEY_new_by_curve_name(NID_secp521r1);
572 break;
573 case ECP_224_BP:
574 case ECP_256_BP:
575 case ECP_384_BP:
576 case ECP_512_BP:
577 this->key = ec_key_new_brainpool(group);
578 break;
579 default:
580 this->key = NULL;
581 break;
582 }
583
584 if (!this->key)
585 {
586 free(this);
587 return NULL;
588 }
589
590 /* caching the EC group */
591 this->ec_group = EC_KEY_get0_group(this->key);
592
593 this->pub_key = EC_POINT_new(this->ec_group);
594 if (!this->pub_key)
595 {
596 destroy(this);
597 return NULL;
598 }
599
600 /* generate an EC private (public) key */
601 if (!EC_KEY_generate_key(this->key))
602 {
603 destroy(this);
604 return NULL;
605 }
606
607 return &this->public;
608 }
609 #endif /* OPENSSL_NO_EC */