1 /* Originally written by Bodo Moeller and Nils Larsch for the OpenSSL project.
2  * ====================================================================
3  * Copyright (c) 1998-2005 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  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
57  *
58  * Portions of the attached software ("Contribution") are developed by
59  * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
60  *
61  * The Contribution is licensed pursuant to the OpenSSL open source
62  * license provided above.
63  *
64  * The elliptic curve binary polynomial software is originally written by
65  * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems
66  * Laboratories. */
67 
68 #include <openssl/ec.h>
69 
70 #include <openssl/bn.h>
71 #include <openssl/err.h>
72 #include <openssl/mem.h>
73 
74 #include "internal.h"
75 
76 
EC_GFp_mont_method(void)77 const EC_METHOD *EC_GFp_mont_method(void) {
78   static const EC_METHOD ret = {EC_FLAGS_DEFAULT_OCT,
79                                 ec_GFp_mont_group_init,
80                                 ec_GFp_mont_group_finish,
81                                 ec_GFp_mont_group_clear_finish,
82                                 ec_GFp_mont_group_copy,
83                                 ec_GFp_mont_group_set_curve,
84                                 ec_GFp_simple_group_get_curve,
85                                 ec_GFp_simple_group_get_degree,
86                                 ec_GFp_simple_group_check_discriminant,
87                                 ec_GFp_simple_point_init,
88                                 ec_GFp_simple_point_finish,
89                                 ec_GFp_simple_point_clear_finish,
90                                 ec_GFp_simple_point_copy,
91                                 ec_GFp_simple_point_set_to_infinity,
92                                 ec_GFp_simple_set_Jprojective_coordinates_GFp,
93                                 ec_GFp_simple_get_Jprojective_coordinates_GFp,
94                                 ec_GFp_simple_point_set_affine_coordinates,
95                                 ec_GFp_simple_point_get_affine_coordinates,
96                                 0,
97                                 0,
98                                 0,
99                                 ec_GFp_simple_add,
100                                 ec_GFp_simple_dbl,
101                                 ec_GFp_simple_invert,
102                                 ec_GFp_simple_is_at_infinity,
103                                 ec_GFp_simple_is_on_curve,
104                                 ec_GFp_simple_cmp,
105                                 ec_GFp_simple_make_affine,
106                                 ec_GFp_simple_points_make_affine,
107                                 0 /* mul */,
108                                 0 /* precompute_mult */,
109                                 0 /* have_precompute_mult */,
110                                 ec_GFp_mont_field_mul,
111                                 ec_GFp_mont_field_sqr,
112                                 0 /* field_div */,
113                                 ec_GFp_mont_field_encode,
114                                 ec_GFp_mont_field_decode,
115                                 ec_GFp_mont_field_set_to_one};
116 
117   return &ret;
118 }
119 
ec_GFp_mont_group_init(EC_GROUP * group)120 int ec_GFp_mont_group_init(EC_GROUP *group) {
121   int ok;
122 
123   ok = ec_GFp_simple_group_init(group);
124   group->mont = NULL;
125   group->one = NULL;
126   return ok;
127 }
128 
ec_GFp_mont_group_finish(EC_GROUP * group)129 void ec_GFp_mont_group_finish(EC_GROUP *group) {
130   BN_MONT_CTX_free(group->mont);
131   group->mont = NULL;
132   BN_free(group->one);
133   group->one = NULL;
134   ec_GFp_simple_group_finish(group);
135 }
136 
ec_GFp_mont_group_clear_finish(EC_GROUP * group)137 void ec_GFp_mont_group_clear_finish(EC_GROUP *group) {
138   BN_MONT_CTX_free(group->mont);
139   group->mont = NULL;
140   BN_clear_free(group->one);
141   group->one = NULL;
142   ec_GFp_simple_group_clear_finish(group);
143 }
144 
ec_GFp_mont_group_copy(EC_GROUP * dest,const EC_GROUP * src)145 int ec_GFp_mont_group_copy(EC_GROUP *dest, const EC_GROUP *src) {
146   BN_MONT_CTX_free(dest->mont);
147   dest->mont = NULL;
148   BN_clear_free(dest->one);
149   dest->one = NULL;
150 
151   if (!ec_GFp_simple_group_copy(dest, src)) {
152     return 0;
153   }
154 
155   if (src->mont != NULL) {
156     dest->mont = BN_MONT_CTX_new();
157     if (dest->mont == NULL) {
158       return 0;
159     }
160     if (!BN_MONT_CTX_copy(dest->mont, src->mont)) {
161       goto err;
162     }
163   }
164   if (src->one != NULL) {
165     dest->one = BN_dup(src->one);
166     if (dest->one == NULL) {
167       goto err;
168     }
169   }
170 
171   return 1;
172 
173 err:
174   BN_MONT_CTX_free(dest->mont);
175   dest->mont = NULL;
176   return 0;
177 }
178 
ec_GFp_mont_group_set_curve(EC_GROUP * group,const BIGNUM * p,const BIGNUM * a,const BIGNUM * b,BN_CTX * ctx)179 int ec_GFp_mont_group_set_curve(EC_GROUP *group, const BIGNUM *p,
180                                 const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx) {
181   BN_CTX *new_ctx = NULL;
182   BN_MONT_CTX *mont = NULL;
183   BIGNUM *one = NULL;
184   int ret = 0;
185 
186   BN_MONT_CTX_free(group->mont);
187   group->mont = NULL;
188   BN_free(group->one);
189   group->one = NULL;
190 
191   if (ctx == NULL) {
192     ctx = new_ctx = BN_CTX_new();
193     if (ctx == NULL) {
194       return 0;
195     }
196   }
197 
198   mont = BN_MONT_CTX_new();
199   if (mont == NULL) {
200     goto err;
201   }
202   if (!BN_MONT_CTX_set(mont, p, ctx)) {
203     OPENSSL_PUT_ERROR(EC, ec_GFp_mont_group_set_curve, ERR_R_BN_LIB);
204     goto err;
205   }
206   one = BN_new();
207   if (one == NULL || !BN_to_montgomery(one, BN_value_one(), mont, ctx)) {
208     goto err;
209   }
210 
211   group->mont = mont;
212   mont = NULL;
213   group->one = one;
214   one = NULL;
215 
216   ret = ec_GFp_simple_group_set_curve(group, p, a, b, ctx);
217 
218   if (!ret) {
219     BN_MONT_CTX_free(group->mont);
220     group->mont = NULL;
221     BN_free(group->one);
222     group->one = NULL;
223   }
224 
225 err:
226   BN_CTX_free(new_ctx);
227   BN_MONT_CTX_free(mont);
228   BN_free(one);
229   return ret;
230 }
231 
ec_GFp_mont_field_mul(const EC_GROUP * group,BIGNUM * r,const BIGNUM * a,const BIGNUM * b,BN_CTX * ctx)232 int ec_GFp_mont_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
233                           const BIGNUM *b, BN_CTX *ctx) {
234   if (group->mont == NULL) {
235     OPENSSL_PUT_ERROR(EC, ec_GFp_mont_field_mul, EC_R_NOT_INITIALIZED);
236     return 0;
237   }
238 
239   return BN_mod_mul_montgomery(r, a, b, group->mont, ctx);
240 }
241 
ec_GFp_mont_field_sqr(const EC_GROUP * group,BIGNUM * r,const BIGNUM * a,BN_CTX * ctx)242 int ec_GFp_mont_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
243                           BN_CTX *ctx) {
244   if (group->mont == NULL) {
245     OPENSSL_PUT_ERROR(EC, ec_GFp_mont_field_sqr, EC_R_NOT_INITIALIZED);
246     return 0;
247   }
248 
249   return BN_mod_mul_montgomery(r, a, a, group->mont, ctx);
250 }
251 
ec_GFp_mont_field_encode(const EC_GROUP * group,BIGNUM * r,const BIGNUM * a,BN_CTX * ctx)252 int ec_GFp_mont_field_encode(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
253                              BN_CTX *ctx) {
254   if (group->mont == NULL) {
255     OPENSSL_PUT_ERROR(EC, ec_GFp_mont_field_encode, EC_R_NOT_INITIALIZED);
256     return 0;
257   }
258 
259   return BN_to_montgomery(r, a, group->mont, ctx);
260 }
261 
ec_GFp_mont_field_decode(const EC_GROUP * group,BIGNUM * r,const BIGNUM * a,BN_CTX * ctx)262 int ec_GFp_mont_field_decode(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
263                              BN_CTX *ctx) {
264   if (group->mont == NULL) {
265     OPENSSL_PUT_ERROR(EC, ec_GFp_mont_field_decode, EC_R_NOT_INITIALIZED);
266     return 0;
267   }
268 
269   return BN_from_montgomery(r, a, group->mont, ctx);
270 }
271 
ec_GFp_mont_field_set_to_one(const EC_GROUP * group,BIGNUM * r,BN_CTX * ctx)272 int ec_GFp_mont_field_set_to_one(const EC_GROUP *group, BIGNUM *r,
273                                  BN_CTX *ctx) {
274   if (group->one == NULL) {
275     OPENSSL_PUT_ERROR(EC, ec_GFp_mont_field_set_to_one, EC_R_NOT_INITIALIZED);
276     return 0;
277   }
278 
279   if (!BN_copy(r, group->one)) {
280     return 0;
281   }
282   return 1;
283 }
284