1 /* $OpenBSD: ecp_mont.c,v 1.20 2021/09/08 17:29:21 tb Exp $ */ 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 69 const EC_METHOD * 70 EC_GFp_mont_method(void) 71 { 72 static const EC_METHOD ret = { 73 .flags = EC_FLAGS_DEFAULT_OCT, 74 .field_type = NID_X9_62_prime_field, 75 .group_init = ec_GFp_mont_group_init, 76 .group_finish = ec_GFp_mont_group_finish, 77 .group_clear_finish = ec_GFp_mont_group_clear_finish, 78 .group_copy = ec_GFp_mont_group_copy, 79 .group_set_curve = ec_GFp_mont_group_set_curve, 80 .group_get_curve = ec_GFp_simple_group_get_curve, 81 .group_get_degree = ec_GFp_simple_group_get_degree, 82 .group_order_bits = ec_group_simple_order_bits, 83 .group_check_discriminant = 84 ec_GFp_simple_group_check_discriminant, 85 .point_init = ec_GFp_simple_point_init, 86 .point_finish = ec_GFp_simple_point_finish, 87 .point_clear_finish = ec_GFp_simple_point_clear_finish, 88 .point_copy = ec_GFp_simple_point_copy, 89 .point_set_to_infinity = ec_GFp_simple_point_set_to_infinity, 90 .point_set_Jprojective_coordinates = 91 ec_GFp_simple_set_Jprojective_coordinates, 92 .point_get_Jprojective_coordinates = 93 ec_GFp_simple_get_Jprojective_coordinates, 94 .point_set_affine_coordinates = 95 ec_GFp_simple_point_set_affine_coordinates, 96 .point_get_affine_coordinates = 97 ec_GFp_simple_point_get_affine_coordinates, 98 .add = ec_GFp_simple_add, 99 .dbl = ec_GFp_simple_dbl, 100 .invert = ec_GFp_simple_invert, 101 .is_at_infinity = ec_GFp_simple_is_at_infinity, 102 .is_on_curve = ec_GFp_simple_is_on_curve, 103 .point_cmp = ec_GFp_simple_cmp, 104 .make_affine = ec_GFp_simple_make_affine, 105 .points_make_affine = ec_GFp_simple_points_make_affine, 106 .mul_generator_ct = ec_GFp_simple_mul_generator_ct, 107 .mul_single_ct = ec_GFp_simple_mul_single_ct, 108 .mul_double_nonct = ec_GFp_simple_mul_double_nonct, 109 .field_mul = ec_GFp_mont_field_mul, 110 .field_sqr = ec_GFp_mont_field_sqr, 111 .field_encode = ec_GFp_mont_field_encode, 112 .field_decode = ec_GFp_mont_field_decode, 113 .field_set_to_one = ec_GFp_mont_field_set_to_one, 114 .blind_coordinates = ec_GFp_simple_blind_coordinates, 115 }; 116 117 return &ret; 118 } 119 120 121 int 122 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 } 131 132 133 void 134 ec_GFp_mont_group_finish(EC_GROUP * group) 135 { 136 BN_MONT_CTX_free(group->field_data1); 137 group->field_data1 = NULL; 138 BN_free(group->field_data2); 139 group->field_data2 = NULL; 140 ec_GFp_simple_group_finish(group); 141 } 142 143 144 void 145 ec_GFp_mont_group_clear_finish(EC_GROUP * group) 146 { 147 BN_MONT_CTX_free(group->field_data1); 148 group->field_data1 = NULL; 149 BN_clear_free(group->field_data2); 150 group->field_data2 = NULL; 151 ec_GFp_simple_group_clear_finish(group); 152 } 153 154 155 int 156 ec_GFp_mont_group_copy(EC_GROUP * dest, const EC_GROUP * src) 157 { 158 BN_MONT_CTX_free(dest->field_data1); 159 dest->field_data1 = NULL; 160 BN_clear_free(dest->field_data2); 161 dest->field_data2 = NULL; 162 163 if (!ec_GFp_simple_group_copy(dest, src)) 164 return 0; 165 166 if (src->field_data1 != NULL) { 167 dest->field_data1 = BN_MONT_CTX_new(); 168 if (dest->field_data1 == NULL) 169 return 0; 170 if (!BN_MONT_CTX_copy(dest->field_data1, src->field_data1)) 171 goto err; 172 } 173 if (src->field_data2 != NULL) { 174 dest->field_data2 = BN_dup(src->field_data2); 175 if (dest->field_data2 == NULL) 176 goto err; 177 } 178 return 1; 179 180 err: 181 if (dest->field_data1 != NULL) { 182 BN_MONT_CTX_free(dest->field_data1); 183 dest->field_data1 = NULL; 184 } 185 return 0; 186 } 187 188 189 int 190 ec_GFp_mont_group_set_curve(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, 191 const BIGNUM *b, BN_CTX *ctx) 192 { 193 BN_CTX *new_ctx = NULL; 194 BN_MONT_CTX *mont = NULL; 195 BIGNUM *one = NULL; 196 int ret = 0; 197 198 BN_MONT_CTX_free(group->field_data1); 199 group->field_data1 = NULL; 200 BN_free(group->field_data2); 201 group->field_data2 = NULL; 202 if (ctx == NULL) { 203 ctx = new_ctx = BN_CTX_new(); 204 if (ctx == NULL) 205 return 0; 206 } 207 mont = BN_MONT_CTX_new(); 208 if (mont == NULL) 209 goto err; 210 if (!BN_MONT_CTX_set(mont, p, ctx)) { 211 ECerror(ERR_R_BN_LIB); 212 goto err; 213 } 214 one = BN_new(); 215 if (one == NULL) 216 goto err; 217 if (!BN_to_montgomery(one, BN_value_one(), mont, ctx)) 218 goto err; 219 220 group->field_data1 = mont; 221 mont = NULL; 222 group->field_data2 = one; 223 one = NULL; 224 225 ret = ec_GFp_simple_group_set_curve(group, p, a, b, ctx); 226 227 if (!ret) { 228 BN_MONT_CTX_free(group->field_data1); 229 group->field_data1 = NULL; 230 BN_free(group->field_data2); 231 group->field_data2 = NULL; 232 } 233 err: 234 BN_CTX_free(new_ctx); 235 BN_MONT_CTX_free(mont); 236 BN_free(one); 237 return ret; 238 } 239 240 241 int 242 ec_GFp_mont_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, 243 const BIGNUM *b, BN_CTX *ctx) 244 { 245 if (group->field_data1 == NULL) { 246 ECerror(EC_R_NOT_INITIALIZED); 247 return 0; 248 } 249 return BN_mod_mul_montgomery(r, a, b, group->field_data1, ctx); 250 } 251 252 253 int 254 ec_GFp_mont_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, 255 BN_CTX *ctx) 256 { 257 if (group->field_data1 == NULL) { 258 ECerror(EC_R_NOT_INITIALIZED); 259 return 0; 260 } 261 return BN_mod_mul_montgomery(r, a, a, group->field_data1, ctx); 262 } 263 264 265 int 266 ec_GFp_mont_field_encode(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, 267 BN_CTX *ctx) 268 { 269 if (group->field_data1 == NULL) { 270 ECerror(EC_R_NOT_INITIALIZED); 271 return 0; 272 } 273 return BN_to_montgomery(r, a, (BN_MONT_CTX *) group->field_data1, ctx); 274 } 275 276 277 int 278 ec_GFp_mont_field_decode(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, 279 BN_CTX *ctx) 280 { 281 if (group->field_data1 == NULL) { 282 ECerror(EC_R_NOT_INITIALIZED); 283 return 0; 284 } 285 return BN_from_montgomery(r, a, group->field_data1, ctx); 286 } 287 288 289 int 290 ec_GFp_mont_field_set_to_one(const EC_GROUP *group, BIGNUM *r, BN_CTX *ctx) 291 { 292 if (group->field_data2 == NULL) { 293 ECerror(EC_R_NOT_INITIALIZED); 294 return 0; 295 } 296 if (!BN_copy(r, group->field_data2)) 297 return 0; 298 return 1; 299 } 300