ecp_mont.c revision 160814 
1/* crypto/ec/ecp_mont.c */
2/*
3 * Originally written by Bodo Moeller for the OpenSSL project.
4 */
5/* ====================================================================
6 * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in
17 *    the documentation and/or other materials provided with the
18 *    distribution.
19 *
20 * 3. All advertising materials mentioning features or use of this
21 *    software must display the following acknowledgment:
22 *    "This product includes software developed by the OpenSSL Project
23 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
24 *
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 *    endorse or promote products derived from this software without
27 *    prior written permission. For written permission, please contact
28 *    openssl-core@openssl.org.
29 *
30 * 5. Products derived from this software may not be called "OpenSSL"
31 *    nor may "OpenSSL" appear in their names without prior written
32 *    permission of the OpenSSL Project.
33 *
34 * 6. Redistributions of any form whatsoever must retain the following
35 *    acknowledgment:
36 *    "This product includes software developed by the OpenSSL Project
37 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
38 *
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
52 *
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com).  This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
56 *
57 */
58/* ====================================================================
59 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
60 * Portions of this software developed by SUN MICROSYSTEMS, INC.,
61 * and contributed to the OpenSSL project.
62 */
63
64#include <openssl/err.h>
65
66#include "ec_lcl.h"
67
68
69const EC_METHOD *EC_GFp_mont_method(void)
70	{
71	static const EC_METHOD ret = {
72		NID_X9_62_prime_field,
73		ec_GFp_mont_group_init,
74		ec_GFp_mont_group_finish,
75		ec_GFp_mont_group_clear_finish,
76		ec_GFp_mont_group_copy,
77		ec_GFp_mont_group_set_curve,
78		ec_GFp_simple_group_get_curve,
79		ec_GFp_simple_group_get_degree,
80		ec_GFp_simple_group_check_discriminant,
81		ec_GFp_simple_point_init,
82		ec_GFp_simple_point_finish,
83		ec_GFp_simple_point_clear_finish,
84		ec_GFp_simple_point_copy,
85		ec_GFp_simple_point_set_to_infinity,
86		ec_GFp_simple_set_Jprojective_coordinates_GFp,
87		ec_GFp_simple_get_Jprojective_coordinates_GFp,
88		ec_GFp_simple_point_set_affine_coordinates,
89		ec_GFp_simple_point_get_affine_coordinates,
90		ec_GFp_simple_set_compressed_coordinates,
91		ec_GFp_simple_point2oct,
92		ec_GFp_simple_oct2point,
93		ec_GFp_simple_add,
94		ec_GFp_simple_dbl,
95		ec_GFp_simple_invert,
96		ec_GFp_simple_is_at_infinity,
97		ec_GFp_simple_is_on_curve,
98		ec_GFp_simple_cmp,
99		ec_GFp_simple_make_affine,
100		ec_GFp_simple_points_make_affine,
101		0 /* mul */,
102		0 /* precompute_mult */,
103		0 /* have_precompute_mult */,
104		ec_GFp_mont_field_mul,
105		ec_GFp_mont_field_sqr,
106		0 /* field_div */,
107		ec_GFp_mont_field_encode,
108		ec_GFp_mont_field_decode,
109		ec_GFp_mont_field_set_to_one };
110
111	return &ret;
112	}
113
114
115int ec_GFp_mont_group_init(EC_GROUP *group)
116	{
117	int ok;
118
119	ok = ec_GFp_simple_group_init(group);
120	group->field_data1 = NULL;
121	group->field_data2 = NULL;
122	return ok;
123	}
124
125
126void ec_GFp_mont_group_finish(EC_GROUP *group)
127	{
128	if (group->field_data1 != NULL)
129		{
130		BN_MONT_CTX_free(group->field_data1);
131		group->field_data1 = NULL;
132		}
133	if (group->field_data2 != NULL)
134		{
135		BN_free(group->field_data2);
136		group->field_data2 = NULL;
137		}
138	ec_GFp_simple_group_finish(group);
139	}
140
141
142void ec_GFp_mont_group_clear_finish(EC_GROUP *group)
143	{
144	if (group->field_data1 != NULL)
145		{
146		BN_MONT_CTX_free(group->field_data1);
147		group->field_data1 = NULL;
148		}
149	if (group->field_data2 != NULL)
150		{
151		BN_clear_free(group->field_data2);
152		group->field_data2 = NULL;
153		}
154	ec_GFp_simple_group_clear_finish(group);
155	}
156
157
158int ec_GFp_mont_group_copy(EC_GROUP *dest, const EC_GROUP *src)
159	{
160	if (dest->field_data1 != NULL)
161		{
162		BN_MONT_CTX_free(dest->field_data1);
163		dest->field_data1 = NULL;
164		}
165	if (dest->field_data2 != NULL)
166		{
167		BN_clear_free(dest->field_data2);
168		dest->field_data2 = NULL;
169		}
170
171	if (!ec_GFp_simple_group_copy(dest, src)) return 0;
172
173	if (src->field_data1 != NULL)
174		{
175		dest->field_data1 = BN_MONT_CTX_new();
176		if (dest->field_data1 == NULL) return 0;
177		if (!BN_MONT_CTX_copy(dest->field_data1, src->field_data1)) goto err;
178		}
179	if (src->field_data2 != NULL)
180		{
181		dest->field_data2 = BN_dup(src->field_data2);
182		if (dest->field_data2 == NULL) goto err;
183		}
184
185	return 1;
186
187 err:
188	if (dest->field_data1 != NULL)
189		{
190		BN_MONT_CTX_free(dest->field_data1);
191		dest->field_data1 = NULL;
192		}
193	return 0;
194	}
195
196
197int ec_GFp_mont_group_set_curve(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
198	{
199	BN_CTX *new_ctx = NULL;
200	BN_MONT_CTX *mont = NULL;
201	BIGNUM *one = NULL;
202	int ret = 0;
203
204	if (group->field_data1 != NULL)
205		{
206		BN_MONT_CTX_free(group->field_data1);
207		group->field_data1 = NULL;
208		}
209	if (group->field_data2 != NULL)
210		{
211		BN_free(group->field_data2);
212		group->field_data2 = NULL;
213		}
214
215	if (ctx == NULL)
216		{
217		ctx = new_ctx = BN_CTX_new();
218		if (ctx == NULL)
219			return 0;
220		}
221
222	mont = BN_MONT_CTX_new();
223	if (mont == NULL) goto err;
224	if (!BN_MONT_CTX_set(mont, p, ctx))
225		{
226		ECerr(EC_F_EC_GFP_MONT_GROUP_SET_CURVE, ERR_R_BN_LIB);
227		goto err;
228		}
229	one = BN_new();
230	if (one == NULL) goto err;
231	if (!BN_to_montgomery(one, BN_value_one(), mont, ctx)) goto err;
232
233	group->field_data1 = mont;
234	mont = NULL;
235	group->field_data2 = one;
236	one = NULL;
237
238	ret = ec_GFp_simple_group_set_curve(group, p, a, b, ctx);
239
240	if (!ret)
241		{
242		BN_MONT_CTX_free(group->field_data1);
243		group->field_data1 = NULL;
244		BN_free(group->field_data2);
245		group->field_data2 = NULL;
246		}
247
248 err:
249	if (new_ctx != NULL)
250		BN_CTX_free(new_ctx);
251	if (mont != NULL)
252		BN_MONT_CTX_free(mont);
253	return ret;
254	}
255
256
257int ec_GFp_mont_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
258	{
259	if (group->field_data1 == NULL)
260		{
261		ECerr(EC_F_EC_GFP_MONT_FIELD_MUL, EC_R_NOT_INITIALIZED);
262		return 0;
263		}
264
265	return BN_mod_mul_montgomery(r, a, b, group->field_data1, ctx);
266	}
267
268
269int ec_GFp_mont_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
270	{
271	if (group->field_data1 == NULL)
272		{
273		ECerr(EC_F_EC_GFP_MONT_FIELD_SQR, EC_R_NOT_INITIALIZED);
274		return 0;
275		}
276
277	return BN_mod_mul_montgomery(r, a, a, group->field_data1, ctx);
278	}
279
280
281int ec_GFp_mont_field_encode(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
282	{
283	if (group->field_data1 == NULL)
284		{
285		ECerr(EC_F_EC_GFP_MONT_FIELD_ENCODE, EC_R_NOT_INITIALIZED);
286		return 0;
287		}
288
289	return BN_to_montgomery(r, a, (BN_MONT_CTX *)group->field_data1, ctx);
290	}
291
292
293int ec_GFp_mont_field_decode(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
294	{
295	if (group->field_data1 == NULL)
296		{
297		ECerr(EC_F_EC_GFP_MONT_FIELD_DECODE, EC_R_NOT_INITIALIZED);
298		return 0;
299		}
300
301	return BN_from_montgomery(r, a, group->field_data1, ctx);
302	}
303
304
305int ec_GFp_mont_field_set_to_one(const EC_GROUP *group, BIGNUM *r, BN_CTX *ctx)
306	{
307	if (group->field_data2 == NULL)
308		{
309		ECerr(EC_F_EC_GFP_MONT_FIELD_SET_TO_ONE, EC_R_NOT_INITIALIZED);
310		return 0;
311		}
312
313	if (!BN_copy(r, group->field_data2)) return 0;
314	return 1;
315	}
316