ecp_mont.c revision 296465 
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
68const EC_METHOD *EC_GFp_mont_method(void)
69{
70    static const EC_METHOD ret = {
71        NID_X9_62_prime_field,
72        ec_GFp_mont_group_init,
73        ec_GFp_mont_group_finish,
74        ec_GFp_mont_group_clear_finish,
75        ec_GFp_mont_group_copy,
76        ec_GFp_mont_group_set_curve,
77        ec_GFp_simple_group_get_curve,
78        ec_GFp_simple_group_get_degree,
79        ec_GFp_simple_group_check_discriminant,
80        ec_GFp_simple_point_init,
81        ec_GFp_simple_point_finish,
82        ec_GFp_simple_point_clear_finish,
83        ec_GFp_simple_point_copy,
84        ec_GFp_simple_point_set_to_infinity,
85        ec_GFp_simple_set_Jprojective_coordinates_GFp,
86        ec_GFp_simple_get_Jprojective_coordinates_GFp,
87        ec_GFp_simple_point_set_affine_coordinates,
88        ec_GFp_simple_point_get_affine_coordinates,
89        ec_GFp_simple_set_compressed_coordinates,
90        ec_GFp_simple_point2oct,
91        ec_GFp_simple_oct2point,
92        ec_GFp_simple_add,
93        ec_GFp_simple_dbl,
94        ec_GFp_simple_invert,
95        ec_GFp_simple_is_at_infinity,
96        ec_GFp_simple_is_on_curve,
97        ec_GFp_simple_cmp,
98        ec_GFp_simple_make_affine,
99        ec_GFp_simple_points_make_affine,
100        0 /* mul */ ,
101        0 /* precompute_mult */ ,
102        0 /* have_precompute_mult */ ,
103        ec_GFp_mont_field_mul,
104        ec_GFp_mont_field_sqr,
105        0 /* field_div */ ,
106        ec_GFp_mont_field_encode,
107        ec_GFp_mont_field_decode,
108        ec_GFp_mont_field_set_to_one
109    };
110
111    return &ret;
112}
113
114int ec_GFp_mont_group_init(EC_GROUP *group)
115{
116    int ok;
117
118    ok = ec_GFp_simple_group_init(group);
119    group->field_data1 = NULL;
120    group->field_data2 = NULL;
121    return ok;
122}
123
124void ec_GFp_mont_group_finish(EC_GROUP *group)
125{
126    if (group->field_data1 != NULL) {
127        BN_MONT_CTX_free(group->field_data1);
128        group->field_data1 = NULL;
129    }
130    if (group->field_data2 != NULL) {
131        BN_free(group->field_data2);
132        group->field_data2 = NULL;
133    }
134    ec_GFp_simple_group_finish(group);
135}
136
137void ec_GFp_mont_group_clear_finish(EC_GROUP *group)
138{
139    if (group->field_data1 != NULL) {
140        BN_MONT_CTX_free(group->field_data1);
141        group->field_data1 = NULL;
142    }
143    if (group->field_data2 != NULL) {
144        BN_clear_free(group->field_data2);
145        group->field_data2 = NULL;
146    }
147    ec_GFp_simple_group_clear_finish(group);
148}
149
150int ec_GFp_mont_group_copy(EC_GROUP *dest, const EC_GROUP *src)
151{
152    if (dest->field_data1 != NULL) {
153        BN_MONT_CTX_free(dest->field_data1);
154        dest->field_data1 = NULL;
155    }
156    if (dest->field_data2 != NULL) {
157        BN_clear_free(dest->field_data2);
158        dest->field_data2 = NULL;
159    }
160
161    if (!ec_GFp_simple_group_copy(dest, src))
162        return 0;
163
164    if (src->field_data1 != NULL) {
165        dest->field_data1 = BN_MONT_CTX_new();
166        if (dest->field_data1 == NULL)
167            return 0;
168        if (!BN_MONT_CTX_copy(dest->field_data1, src->field_data1))
169            goto err;
170    }
171    if (src->field_data2 != NULL) {
172        dest->field_data2 = BN_dup(src->field_data2);
173        if (dest->field_data2 == NULL)
174            goto err;
175    }
176
177    return 1;
178
179 err:
180    if (dest->field_data1 != NULL) {
181        BN_MONT_CTX_free(dest->field_data1);
182        dest->field_data1 = NULL;
183    }
184    return 0;
185}
186
187int ec_GFp_mont_group_set_curve(EC_GROUP *group, const BIGNUM *p,
188                                const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
189{
190    BN_CTX *new_ctx = NULL;
191    BN_MONT_CTX *mont = NULL;
192    BIGNUM *one = NULL;
193    int ret = 0;
194
195    if (group->field_data1 != NULL) {
196        BN_MONT_CTX_free(group->field_data1);
197        group->field_data1 = NULL;
198    }
199    if (group->field_data2 != NULL) {
200        BN_free(group->field_data2);
201        group->field_data2 = NULL;
202    }
203
204    if (ctx == NULL) {
205        ctx = new_ctx = BN_CTX_new();
206        if (ctx == NULL)
207            return 0;
208    }
209
210    mont = BN_MONT_CTX_new();
211    if (mont == NULL)
212        goto err;
213    if (!BN_MONT_CTX_set(mont, p, ctx)) {
214        ECerr(EC_F_EC_GFP_MONT_GROUP_SET_CURVE, ERR_R_BN_LIB);
215        goto err;
216    }
217    one = BN_new();
218    if (one == NULL)
219        goto err;
220    if (!BN_to_montgomery(one, BN_value_one(), mont, ctx))
221        goto err;
222
223    group->field_data1 = mont;
224    mont = NULL;
225    group->field_data2 = one;
226    one = NULL;
227
228    ret = ec_GFp_simple_group_set_curve(group, p, a, b, ctx);
229
230    if (!ret) {
231        BN_MONT_CTX_free(group->field_data1);
232        group->field_data1 = NULL;
233        BN_free(group->field_data2);
234        group->field_data2 = NULL;
235    }
236
237 err:
238    if (new_ctx != NULL)
239        BN_CTX_free(new_ctx);
240    if (mont != NULL)
241        BN_MONT_CTX_free(mont);
242    return ret;
243}
244
245int ec_GFp_mont_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
246                          const BIGNUM *b, BN_CTX *ctx)
247{
248    if (group->field_data1 == NULL) {
249        ECerr(EC_F_EC_GFP_MONT_FIELD_MUL, EC_R_NOT_INITIALIZED);
250        return 0;
251    }
252
253    return BN_mod_mul_montgomery(r, a, b, group->field_data1, ctx);
254}
255
256int ec_GFp_mont_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
257                          BN_CTX *ctx)
258{
259    if (group->field_data1 == NULL) {
260        ECerr(EC_F_EC_GFP_MONT_FIELD_SQR, EC_R_NOT_INITIALIZED);
261        return 0;
262    }
263
264    return BN_mod_mul_montgomery(r, a, a, group->field_data1, ctx);
265}
266
267int ec_GFp_mont_field_encode(const EC_GROUP *group, BIGNUM *r,
268                             const BIGNUM *a, BN_CTX *ctx)
269{
270    if (group->field_data1 == NULL) {
271        ECerr(EC_F_EC_GFP_MONT_FIELD_ENCODE, EC_R_NOT_INITIALIZED);
272        return 0;
273    }
274
275    return BN_to_montgomery(r, a, (BN_MONT_CTX *)group->field_data1, ctx);
276}
277
278int ec_GFp_mont_field_decode(const EC_GROUP *group, BIGNUM *r,
279                             const BIGNUM *a, BN_CTX *ctx)
280{
281    if (group->field_data1 == NULL) {
282        ECerr(EC_F_EC_GFP_MONT_FIELD_DECODE, EC_R_NOT_INITIALIZED);
283        return 0;
284    }
285
286    return BN_from_montgomery(r, a, group->field_data1, ctx);
287}
288
289int ec_GFp_mont_field_set_to_one(const EC_GROUP *group, BIGNUM *r,
290                                 BN_CTX *ctx)
291{
292    if (group->field_data2 == NULL) {
293        ECerr(EC_F_EC_GFP_MONT_FIELD_SET_TO_ONE, EC_R_NOT_INITIALIZED);
294        return 0;
295    }
296
297    if (!BN_copy(r, group->field_data2))
298        return 0;
299    return 1;
300}
301