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