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#ifdef OPENSSL_FIPS
67#include <openssl/fips.h>
68#endif
69
70#include "ec_lcl.h"
71
72
73const EC_METHOD *EC_GFp_mont_method(void)
74	{
75	static const EC_METHOD ret = {
76		EC_FLAGS_DEFAULT_OCT,
77		NID_X9_62_prime_field,
78		ec_GFp_mont_group_init,
79		ec_GFp_mont_group_finish,
80		ec_GFp_mont_group_clear_finish,
81		ec_GFp_mont_group_copy,
82		ec_GFp_mont_group_set_curve,
83		ec_GFp_simple_group_get_curve,
84		ec_GFp_simple_group_get_degree,
85		ec_GFp_simple_group_check_discriminant,
86		ec_GFp_simple_point_init,
87		ec_GFp_simple_point_finish,
88		ec_GFp_simple_point_clear_finish,
89		ec_GFp_simple_point_copy,
90		ec_GFp_simple_point_set_to_infinity,
91		ec_GFp_simple_set_Jprojective_coordinates_GFp,
92		ec_GFp_simple_get_Jprojective_coordinates_GFp,
93		ec_GFp_simple_point_set_affine_coordinates,
94		ec_GFp_simple_point_get_affine_coordinates,
95		0,0,0,
96		ec_GFp_simple_add,
97		ec_GFp_simple_dbl,
98		ec_GFp_simple_invert,
99		ec_GFp_simple_is_at_infinity,
100		ec_GFp_simple_is_on_curve,
101		ec_GFp_simple_cmp,
102		ec_GFp_simple_make_affine,
103		ec_GFp_simple_points_make_affine,
104		0 /* mul */,
105		0 /* precompute_mult */,
106		0 /* have_precompute_mult */,
107		ec_GFp_mont_field_mul,
108		ec_GFp_mont_field_sqr,
109		0 /* field_div */,
110		ec_GFp_mont_field_encode,
111		ec_GFp_mont_field_decode,
112		ec_GFp_mont_field_set_to_one };
113
114#ifdef OPENSSL_FIPS
115	if (FIPS_mode())
116		return fips_ec_gfp_mont_method();
117#endif
118
119	return &ret;
120	}
121
122
123int ec_GFp_mont_group_init(EC_GROUP *group)
124	{
125	int ok;
126
127	ok = ec_GFp_simple_group_init(group);
128	group->field_data1 = NULL;
129	group->field_data2 = NULL;
130	return ok;
131	}
132
133
134void ec_GFp_mont_group_finish(EC_GROUP *group)
135	{
136	if (group->field_data1 != NULL)
137		{
138		BN_MONT_CTX_free(group->field_data1);
139		group->field_data1 = NULL;
140		}
141	if (group->field_data2 != NULL)
142		{
143		BN_free(group->field_data2);
144		group->field_data2 = NULL;
145		}
146	ec_GFp_simple_group_finish(group);
147	}
148
149
150void ec_GFp_mont_group_clear_finish(EC_GROUP *group)
151	{
152	if (group->field_data1 != NULL)
153		{
154		BN_MONT_CTX_free(group->field_data1);
155		group->field_data1 = NULL;
156		}
157	if (group->field_data2 != NULL)
158		{
159		BN_clear_free(group->field_data2);
160		group->field_data2 = NULL;
161		}
162	ec_GFp_simple_group_clear_finish(group);
163	}
164
165
166int ec_GFp_mont_group_copy(EC_GROUP *dest, const EC_GROUP *src)
167	{
168	if (dest->field_data1 != NULL)
169		{
170		BN_MONT_CTX_free(dest->field_data1);
171		dest->field_data1 = NULL;
172		}
173	if (dest->field_data2 != NULL)
174		{
175		BN_clear_free(dest->field_data2);
176		dest->field_data2 = NULL;
177		}
178
179	if (!ec_GFp_simple_group_copy(dest, src)) return 0;
180
181	if (src->field_data1 != NULL)
182		{
183		dest->field_data1 = BN_MONT_CTX_new();
184		if (dest->field_data1 == NULL) return 0;
185		if (!BN_MONT_CTX_copy(dest->field_data1, src->field_data1)) goto err;
186		}
187	if (src->field_data2 != NULL)
188		{
189		dest->field_data2 = BN_dup(src->field_data2);
190		if (dest->field_data2 == NULL) goto err;
191		}
192
193	return 1;
194
195 err:
196	if (dest->field_data1 != NULL)
197		{
198		BN_MONT_CTX_free(dest->field_data1);
199		dest->field_data1 = NULL;
200		}
201	return 0;
202	}
203
204
205int ec_GFp_mont_group_set_curve(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
206	{
207	BN_CTX *new_ctx = NULL;
208	BN_MONT_CTX *mont = NULL;
209	BIGNUM *one = NULL;
210	int ret = 0;
211
212	if (group->field_data1 != NULL)
213		{
214		BN_MONT_CTX_free(group->field_data1);
215		group->field_data1 = NULL;
216		}
217	if (group->field_data2 != NULL)
218		{
219		BN_free(group->field_data2);
220		group->field_data2 = NULL;
221		}
222
223	if (ctx == NULL)
224		{
225		ctx = new_ctx = BN_CTX_new();
226		if (ctx == NULL)
227			return 0;
228		}
229
230	mont = BN_MONT_CTX_new();
231	if (mont == NULL) goto err;
232	if (!BN_MONT_CTX_set(mont, p, ctx))
233		{
234		ECerr(EC_F_EC_GFP_MONT_GROUP_SET_CURVE, ERR_R_BN_LIB);
235		goto err;
236		}
237	one = BN_new();
238	if (one == NULL) goto err;
239	if (!BN_to_montgomery(one, BN_value_one(), mont, ctx)) goto err;
240
241	group->field_data1 = mont;
242	mont = NULL;
243	group->field_data2 = one;
244	one = NULL;
245
246	ret = ec_GFp_simple_group_set_curve(group, p, a, b, ctx);
247
248	if (!ret)
249		{
250		BN_MONT_CTX_free(group->field_data1);
251		group->field_data1 = NULL;
252		BN_free(group->field_data2);
253		group->field_data2 = NULL;
254		}
255
256 err:
257	if (new_ctx != NULL)
258		BN_CTX_free(new_ctx);
259	if (mont != NULL)
260		BN_MONT_CTX_free(mont);
261	return ret;
262	}
263
264
265int ec_GFp_mont_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
266	{
267	if (group->field_data1 == NULL)
268		{
269		ECerr(EC_F_EC_GFP_MONT_FIELD_MUL, EC_R_NOT_INITIALIZED);
270		return 0;
271		}
272
273	return BN_mod_mul_montgomery(r, a, b, group->field_data1, ctx);
274	}
275
276
277int ec_GFp_mont_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
278	{
279	if (group->field_data1 == NULL)
280		{
281		ECerr(EC_F_EC_GFP_MONT_FIELD_SQR, EC_R_NOT_INITIALIZED);
282		return 0;
283		}
284
285	return BN_mod_mul_montgomery(r, a, a, group->field_data1, ctx);
286	}
287
288
289int ec_GFp_mont_field_encode(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
290	{
291	if (group->field_data1 == NULL)
292		{
293		ECerr(EC_F_EC_GFP_MONT_FIELD_ENCODE, EC_R_NOT_INITIALIZED);
294		return 0;
295		}
296
297	return BN_to_montgomery(r, a, (BN_MONT_CTX *)group->field_data1, ctx);
298	}
299
300
301int ec_GFp_mont_field_decode(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
302	{
303	if (group->field_data1 == NULL)
304		{
305		ECerr(EC_F_EC_GFP_MONT_FIELD_DECODE, EC_R_NOT_INITIALIZED);
306		return 0;
307		}
308
309	return BN_from_montgomery(r, a, group->field_data1, ctx);
310	}
311
312
313int ec_GFp_mont_field_set_to_one(const EC_GROUP *group, BIGNUM *r, BN_CTX *ctx)
314	{
315	if (group->field_data2 == NULL)
316		{
317		ECerr(EC_F_EC_GFP_MONT_FIELD_SET_TO_ONE, EC_R_NOT_INITIALIZED);
318		return 0;
319		}
320
321	if (!BN_copy(r, group->field_data2)) return 0;
322	return 1;
323	}
324