ecp_mont.c revision 109998 
1/* crypto/ec/ecp_mont.c */
2/* ====================================================================
3 * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in
14 *    the documentation and/or other materials provided with the
15 *    distribution.
16 *
17 * 3. All advertising materials mentioning features or use of this
18 *    software must display the following acknowledgment:
19 *    "This product includes software developed by the OpenSSL Project
20 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
21 *
22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23 *    endorse or promote products derived from this software without
24 *    prior written permission. For written permission, please contact
25 *    openssl-core@openssl.org.
26 *
27 * 5. Products derived from this software may not be called "OpenSSL"
28 *    nor may "OpenSSL" appear in their names without prior written
29 *    permission of the OpenSSL Project.
30 *
31 * 6. Redistributions of any form whatsoever must retain the following
32 *    acknowledgment:
33 *    "This product includes software developed by the OpenSSL Project
34 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35 *
36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47 * OF THE POSSIBILITY OF SUCH DAMAGE.
48 * ====================================================================
49 *
50 * This product includes cryptographic software written by Eric Young
51 * (eay@cryptsoft.com).  This product includes software written by Tim
52 * Hudson (tjh@cryptsoft.com).
53 *
54 */
55
56#include <openssl/err.h>
57
58#include "ec_lcl.h"
59
60
61const EC_METHOD *EC_GFp_mont_method(void)
62	{
63	static const EC_METHOD ret = {
64		ec_GFp_mont_group_init,
65		ec_GFp_mont_group_finish,
66		ec_GFp_mont_group_clear_finish,
67		ec_GFp_mont_group_copy,
68		ec_GFp_mont_group_set_curve_GFp,
69		ec_GFp_simple_group_get_curve_GFp,
70		ec_GFp_simple_group_set_generator,
71		ec_GFp_simple_group_get0_generator,
72		ec_GFp_simple_group_get_order,
73		ec_GFp_simple_group_get_cofactor,
74		ec_GFp_simple_point_init,
75		ec_GFp_simple_point_finish,
76		ec_GFp_simple_point_clear_finish,
77		ec_GFp_simple_point_copy,
78		ec_GFp_simple_point_set_to_infinity,
79		ec_GFp_simple_set_Jprojective_coordinates_GFp,
80		ec_GFp_simple_get_Jprojective_coordinates_GFp,
81		ec_GFp_simple_point_set_affine_coordinates_GFp,
82		ec_GFp_simple_point_get_affine_coordinates_GFp,
83		ec_GFp_simple_set_compressed_coordinates_GFp,
84		ec_GFp_simple_point2oct,
85		ec_GFp_simple_oct2point,
86		ec_GFp_simple_add,
87		ec_GFp_simple_dbl,
88		ec_GFp_simple_invert,
89		ec_GFp_simple_is_at_infinity,
90		ec_GFp_simple_is_on_curve,
91		ec_GFp_simple_cmp,
92		ec_GFp_simple_make_affine,
93		ec_GFp_simple_points_make_affine,
94		ec_GFp_mont_field_mul,
95		ec_GFp_mont_field_sqr,
96		ec_GFp_mont_field_encode,
97		ec_GFp_mont_field_decode,
98		ec_GFp_mont_field_set_to_one };
99
100	return &ret;
101	}
102
103
104int ec_GFp_mont_group_init(EC_GROUP *group)
105	{
106	int ok;
107
108	ok = ec_GFp_simple_group_init(group);
109	group->field_data1 = NULL;
110	group->field_data2 = NULL;
111	return ok;
112	}
113
114
115int ec_GFp_mont_group_set_curve_GFp(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
116	{
117	BN_CTX *new_ctx = NULL;
118	BN_MONT_CTX *mont = NULL;
119	BIGNUM *one = NULL;
120	int ret = 0;
121
122	if (group->field_data1 != NULL)
123		{
124		BN_MONT_CTX_free(group->field_data1);
125		group->field_data1 = NULL;
126		}
127	if (group->field_data2 != NULL)
128		{
129		BN_free(group->field_data2);
130		group->field_data2 = NULL;
131		}
132
133	if (ctx == NULL)
134		{
135		ctx = new_ctx = BN_CTX_new();
136		if (ctx == NULL)
137			return 0;
138		}
139
140	mont = BN_MONT_CTX_new();
141	if (mont == NULL) goto err;
142	if (!BN_MONT_CTX_set(mont, p, ctx))
143		{
144		ECerr(EC_F_GFP_MONT_GROUP_SET_CURVE_GFP, ERR_R_BN_LIB);
145		goto err;
146		}
147	one = BN_new();
148	if (one == NULL) goto err;
149	if (!BN_to_montgomery(one, BN_value_one(), mont, ctx)) goto err;
150
151	group->field_data1 = mont;
152	mont = NULL;
153	group->field_data2 = one;
154	one = NULL;
155
156	ret = ec_GFp_simple_group_set_curve_GFp(group, p, a, b, ctx);
157
158	if (!ret)
159		{
160		BN_MONT_CTX_free(group->field_data1);
161		group->field_data1 = NULL;
162		BN_free(group->field_data2);
163		group->field_data2 = NULL;
164		}
165
166 err:
167	if (new_ctx != NULL)
168		BN_CTX_free(new_ctx);
169	if (mont != NULL)
170		BN_MONT_CTX_free(mont);
171	return ret;
172	}
173
174
175void ec_GFp_mont_group_finish(EC_GROUP *group)
176	{
177	if (group->field_data1 != NULL)
178		{
179		BN_MONT_CTX_free(group->field_data1);
180		group->field_data1 = NULL;
181		}
182	if (group->field_data2 != NULL)
183		{
184		BN_free(group->field_data2);
185		group->field_data2 = NULL;
186		}
187	ec_GFp_simple_group_finish(group);
188	}
189
190
191void ec_GFp_mont_group_clear_finish(EC_GROUP *group)
192	{
193	if (group->field_data1 != NULL)
194		{
195		BN_MONT_CTX_free(group->field_data1);
196		group->field_data1 = NULL;
197		}
198	if (group->field_data2 != NULL)
199		{
200		BN_clear_free(group->field_data2);
201		group->field_data2 = NULL;
202		}
203	ec_GFp_simple_group_clear_finish(group);
204	}
205
206
207int ec_GFp_mont_group_copy(EC_GROUP *dest, const EC_GROUP *src)
208	{
209	if (dest->field_data1 != NULL)
210		{
211		BN_MONT_CTX_free(dest->field_data1);
212		dest->field_data1 = NULL;
213		}
214	if (dest->field_data2 != NULL)
215		{
216		BN_clear_free(dest->field_data2);
217		dest->field_data2 = NULL;
218		}
219
220	if (!ec_GFp_simple_group_copy(dest, src)) return 0;
221
222	if (src->field_data1 != NULL)
223		{
224		dest->field_data1 = BN_MONT_CTX_new();
225		if (dest->field_data1 == NULL) return 0;
226		if (!BN_MONT_CTX_copy(dest->field_data1, src->field_data1)) goto err;
227		}
228	if (src->field_data2 != NULL)
229		{
230		dest->field_data2 = BN_dup(src->field_data2);
231		if (dest->field_data2 == NULL) goto err;
232		}
233
234	return 1;
235
236 err:
237	if (dest->field_data1 != NULL)
238		{
239		BN_MONT_CTX_free(dest->field_data1);
240		dest->field_data1 = NULL;
241		}
242	return 0;
243	}
244
245
246int ec_GFp_mont_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
247	{
248	if (group->field_data1 == NULL)
249		{
250		ECerr(EC_F_EC_GFP_MONT_FIELD_MUL, EC_R_NOT_INITIALIZED);
251		return 0;
252		}
253
254	return BN_mod_mul_montgomery(r, a, b, group->field_data1, ctx);
255	}
256
257
258int ec_GFp_mont_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
259	{
260	if (group->field_data1 == NULL)
261		{
262		ECerr(EC_F_EC_GFP_MONT_FIELD_SQR, EC_R_NOT_INITIALIZED);
263		return 0;
264		}
265
266	return BN_mod_mul_montgomery(r, a, a, group->field_data1, ctx);
267	}
268
269
270int ec_GFp_mont_field_encode(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
271	{
272	if (group->field_data1 == NULL)
273		{
274		ECerr(EC_F_EC_GFP_MONT_FIELD_ENCODE, EC_R_NOT_INITIALIZED);
275		return 0;
276		}
277
278	return BN_to_montgomery(r, a, (BN_MONT_CTX *)group->field_data1, ctx);
279	}
280
281
282int ec_GFp_mont_field_decode(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
283	{
284	if (group->field_data1 == NULL)
285		{
286		ECerr(EC_F_EC_GFP_MONT_FIELD_DECODE, EC_R_NOT_INITIALIZED);
287		return 0;
288		}
289
290	return BN_from_montgomery(r, a, group->field_data1, ctx);
291	}
292
293
294int ec_GFp_mont_field_set_to_one(const EC_GROUP *group, BIGNUM *r, BN_CTX *ctx)
295	{
296	if (group->field_data2 == NULL)
297		{
298		ECerr(EC_F_EC_GFP_MONT_FIELD_DECODE, EC_R_NOT_INITIALIZED);
299		return 0;
300		}
301
302	if (!BN_copy(r, group->field_data2)) return 0;
303	return 1;
304	}
305