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| 1 /* crypto/ec/ec2_oct.c */ | |
| 2 /* ==================================================================== | |
| 3 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. | |
| 4 * | |
| 5 * The Elliptic Curve Public-Key Crypto Library (ECC Code) included | |
| 6 * herein is developed by SUN MICROSYSTEMS, INC., and is contributed | |
| 7 * to the OpenSSL project. | |
| 8 * | |
| 9 * The ECC Code is licensed pursuant to the OpenSSL open source | |
| 10 * license provided below. | |
| 11 * | |
| 12 * The software is originally written by Sheueling Chang Shantz and | |
| 13 * Douglas Stebila of Sun Microsystems Laboratories. | |
| 14 * | |
| 15 */ | |
| 16 /* ==================================================================== | |
| 17 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. | |
| 18 * | |
| 19 * Redistribution and use in source and binary forms, with or without | |
| 20 * modification, are permitted provided that the following conditions | |
| 21 * are met: | |
| 22 * | |
| 23 * 1. Redistributions of source code must retain the above copyright | |
| 24 * notice, this list of conditions and the following disclaimer. | |
| 25 * | |
| 26 * 2. Redistributions in binary form must reproduce the above copyright | |
| 27 * notice, this list of conditions and the following disclaimer in | |
| 28 * the documentation and/or other materials provided with the | |
| 29 * distribution. | |
| 30 * | |
| 31 * 3. All advertising materials mentioning features or use of this | |
| 32 * software must display the following acknowledgment: | |
| 33 * "This product includes software developed by the OpenSSL Project | |
| 34 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" | |
| 35 * | |
| 36 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to | |
| 37 * endorse or promote products derived from this software without | |
| 38 * prior written permission. For written permission, please contact | |
| 39 * openssl-core@openssl.org. | |
| 40 * | |
| 41 * 5. Products derived from this software may not be called "OpenSSL" | |
| 42 * nor may "OpenSSL" appear in their names without prior written | |
| 43 * permission of the OpenSSL Project. | |
| 44 * | |
| 45 * 6. Redistributions of any form whatsoever must retain the following | |
| 46 * acknowledgment: | |
| 47 * "This product includes software developed by the OpenSSL Project | |
| 48 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" | |
| 49 * | |
| 50 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY | |
| 51 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
| 53 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR | |
| 54 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
| 55 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
| 56 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
| 57 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 58 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
| 59 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
| 60 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED | |
| 61 * OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 62 * ==================================================================== | |
| 63 * | |
| 64 * This product includes cryptographic software written by Eric Young | |
| 65 * (eay@cryptsoft.com). This product includes software written by Tim | |
| 66 * Hudson (tjh@cryptsoft.com). | |
| 67 * | |
| 68 */ | |
| 69 | |
| 70 #include <openssl/err.h> | |
| 71 | |
| 72 #include "ec_lcl.h" | |
| 73 | |
| 74 #ifndef OPENSSL_NO_EC2M | |
| 75 | |
| 76 /* Calculates and sets the affine coordinates of an EC_POINT from the given | |
| 77 * compressed coordinates. Uses algorithm 2.3.4 of SEC 1. | |
| 78 * Note that the simple implementation only uses affine coordinates. | |
| 79 * | |
| 80 * The method is from the following publication: | |
| 81 * | |
| 82 * Harper, Menezes, Vanstone: | |
| 83 * "Public-Key Cryptosystems with Very Small Key Lengths", | |
| 84 * EUROCRYPT '92, Springer-Verlag LNCS 658, | |
| 85 * published February 1993 | |
| 86 * | |
| 87 * US Patents 6,141,420 and 6,618,483 (Vanstone, Mullin, Agnew) describe | |
| 88 * the same method, but claim no priority date earlier than July 29, 1994 | |
| 89 * (and additionally fail to cite the EUROCRYPT '92 publication as prior art). | |
| 90 */ | |
| 91 int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *p
oint, | |
| 92 const BIGNUM *x_, int y_bit, BN_CTX *ctx) | |
| 93 { | |
| 94 BN_CTX *new_ctx = NULL; | |
| 95 BIGNUM *tmp, *x, *y, *z; | |
| 96 int ret = 0, z0; | |
| 97 | |
| 98 /* clear error queue */ | |
| 99 ERR_clear_error(); | |
| 100 | |
| 101 if (ctx == NULL) | |
| 102 { | |
| 103 ctx = new_ctx = BN_CTX_new(); | |
| 104 if (ctx == NULL) | |
| 105 return 0; | |
| 106 } | |
| 107 | |
| 108 y_bit = (y_bit != 0) ? 1 : 0; | |
| 109 | |
| 110 BN_CTX_start(ctx); | |
| 111 tmp = BN_CTX_get(ctx); | |
| 112 x = BN_CTX_get(ctx); | |
| 113 y = BN_CTX_get(ctx); | |
| 114 z = BN_CTX_get(ctx); | |
| 115 if (z == NULL) goto err; | |
| 116 | |
| 117 if (!BN_GF2m_mod_arr(x, x_, group->poly)) goto err; | |
| 118 if (BN_is_zero(x)) | |
| 119 { | |
| 120 if (!BN_GF2m_mod_sqrt_arr(y, &group->b, group->poly, ctx)) goto
err; | |
| 121 } | |
| 122 else | |
| 123 { | |
| 124 if (!group->meth->field_sqr(group, tmp, x, ctx)) goto err; | |
| 125 if (!group->meth->field_div(group, tmp, &group->b, tmp, ctx)) go
to err; | |
| 126 if (!BN_GF2m_add(tmp, &group->a, tmp)) goto err; | |
| 127 if (!BN_GF2m_add(tmp, x, tmp)) goto err; | |
| 128 if (!BN_GF2m_mod_solve_quad_arr(z, tmp, group->poly, ctx)) | |
| 129 { | |
| 130 unsigned long err = ERR_peek_last_error(); | |
| 131 | |
| 132 if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err
) == BN_R_NO_SOLUTION) | |
| 133 { | |
| 134 ERR_clear_error(); | |
| 135 ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDIN
ATES, EC_R_INVALID_COMPRESSED_POINT); | |
| 136 } | |
| 137 else | |
| 138 ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDIN
ATES, ERR_R_BN_LIB); | |
| 139 goto err; | |
| 140 } | |
| 141 z0 = (BN_is_odd(z)) ? 1 : 0; | |
| 142 if (!group->meth->field_mul(group, y, x, z, ctx)) goto err; | |
| 143 if (z0 != y_bit) | |
| 144 { | |
| 145 if (!BN_GF2m_add(y, y, x)) goto err; | |
| 146 } | |
| 147 } | |
| 148 | |
| 149 if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx)) goto
err; | |
| 150 | |
| 151 ret = 1; | |
| 152 | |
| 153 err: | |
| 154 BN_CTX_end(ctx); | |
| 155 if (new_ctx != NULL) | |
| 156 BN_CTX_free(new_ctx); | |
| 157 return ret; | |
| 158 } | |
| 159 | |
| 160 | |
| 161 /* Converts an EC_POINT to an octet string. | |
| 162 * If buf is NULL, the encoded length will be returned. | |
| 163 * If the length len of buf is smaller than required an error will be returned. | |
| 164 */ | |
| 165 size_t ec_GF2m_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, po
int_conversion_form_t form, | |
| 166 unsigned char *buf, size_t len, BN_CTX *ctx) | |
| 167 { | |
| 168 size_t ret; | |
| 169 BN_CTX *new_ctx = NULL; | |
| 170 int used_ctx = 0; | |
| 171 BIGNUM *x, *y, *yxi; | |
| 172 size_t field_len, i, skip; | |
| 173 | |
| 174 if ((form != POINT_CONVERSION_COMPRESSED) | |
| 175 && (form != POINT_CONVERSION_UNCOMPRESSED) | |
| 176 && (form != POINT_CONVERSION_HYBRID)) | |
| 177 { | |
| 178 ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_INVALID_FORM); | |
| 179 goto err; | |
| 180 } | |
| 181 | |
| 182 if (EC_POINT_is_at_infinity(group, point)) | |
| 183 { | |
| 184 /* encodes to a single 0 octet */ | |
| 185 if (buf != NULL) | |
| 186 { | |
| 187 if (len < 1) | |
| 188 { | |
| 189 ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER
_TOO_SMALL); | |
| 190 return 0; | |
| 191 } | |
| 192 buf[0] = 0; | |
| 193 } | |
| 194 return 1; | |
| 195 } | |
| 196 | |
| 197 | |
| 198 /* ret := required output buffer length */ | |
| 199 field_len = (EC_GROUP_get_degree(group) + 7) / 8; | |
| 200 ret = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*fiel
d_len; | |
| 201 | |
| 202 /* if 'buf' is NULL, just return required length */ | |
| 203 if (buf != NULL) | |
| 204 { | |
| 205 if (len < ret) | |
| 206 { | |
| 207 ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMA
LL); | |
| 208 goto err; | |
| 209 } | |
| 210 | |
| 211 if (ctx == NULL) | |
| 212 { | |
| 213 ctx = new_ctx = BN_CTX_new(); | |
| 214 if (ctx == NULL) | |
| 215 return 0; | |
| 216 } | |
| 217 | |
| 218 BN_CTX_start(ctx); | |
| 219 used_ctx = 1; | |
| 220 x = BN_CTX_get(ctx); | |
| 221 y = BN_CTX_get(ctx); | |
| 222 yxi = BN_CTX_get(ctx); | |
| 223 if (yxi == NULL) goto err; | |
| 224 | |
| 225 if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ct
x)) goto err; | |
| 226 | |
| 227 buf[0] = form; | |
| 228 if ((form != POINT_CONVERSION_UNCOMPRESSED) && !BN_is_zero(x)) | |
| 229 { | |
| 230 if (!group->meth->field_div(group, yxi, y, x, ctx)) goto
err; | |
| 231 if (BN_is_odd(yxi)) buf[0]++; | |
| 232 } | |
| 233 | |
| 234 i = 1; | |
| 235 | |
| 236 skip = field_len - BN_num_bytes(x); | |
| 237 if (skip > field_len) | |
| 238 { | |
| 239 ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERRO
R); | |
| 240 goto err; | |
| 241 } | |
| 242 while (skip > 0) | |
| 243 { | |
| 244 buf[i++] = 0; | |
| 245 skip--; | |
| 246 } | |
| 247 skip = BN_bn2bin(x, buf + i); | |
| 248 i += skip; | |
| 249 if (i != 1 + field_len) | |
| 250 { | |
| 251 ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERRO
R); | |
| 252 goto err; | |
| 253 } | |
| 254 | |
| 255 if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVE
RSION_HYBRID) | |
| 256 { | |
| 257 skip = field_len - BN_num_bytes(y); | |
| 258 if (skip > field_len) | |
| 259 { | |
| 260 ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTER
NAL_ERROR); | |
| 261 goto err; | |
| 262 } | |
| 263 while (skip > 0) | |
| 264 { | |
| 265 buf[i++] = 0; | |
| 266 skip--; | |
| 267 } | |
| 268 skip = BN_bn2bin(y, buf + i); | |
| 269 i += skip; | |
| 270 } | |
| 271 | |
| 272 if (i != ret) | |
| 273 { | |
| 274 ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERRO
R); | |
| 275 goto err; | |
| 276 } | |
| 277 } | |
| 278 | |
| 279 if (used_ctx) | |
| 280 BN_CTX_end(ctx); | |
| 281 if (new_ctx != NULL) | |
| 282 BN_CTX_free(new_ctx); | |
| 283 return ret; | |
| 284 | |
| 285 err: | |
| 286 if (used_ctx) | |
| 287 BN_CTX_end(ctx); | |
| 288 if (new_ctx != NULL) | |
| 289 BN_CTX_free(new_ctx); | |
| 290 return 0; | |
| 291 } | |
| 292 | |
| 293 | |
| 294 /* Converts an octet string representation to an EC_POINT. | |
| 295 * Note that the simple implementation only uses affine coordinates. | |
| 296 */ | |
| 297 int ec_GF2m_simple_oct2point(const EC_GROUP *group, EC_POINT *point, | |
| 298 const unsigned char *buf, size_t len, BN_CTX *ctx) | |
| 299 { | |
| 300 point_conversion_form_t form; | |
| 301 int y_bit; | |
| 302 BN_CTX *new_ctx = NULL; | |
| 303 BIGNUM *x, *y, *yxi; | |
| 304 size_t field_len, enc_len; | |
| 305 int ret = 0; | |
| 306 | |
| 307 if (len == 0) | |
| 308 { | |
| 309 ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL); | |
| 310 return 0; | |
| 311 } | |
| 312 form = buf[0]; | |
| 313 y_bit = form & 1; | |
| 314 form = form & ~1U; | |
| 315 if ((form != 0) && (form != POINT_CONVERSION_COMPRESSED) | |
| 316 && (form != POINT_CONVERSION_UNCOMPRESSED) | |
| 317 && (form != POINT_CONVERSION_HYBRID)) | |
| 318 { | |
| 319 ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING); | |
| 320 return 0; | |
| 321 } | |
| 322 if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit) | |
| 323 { | |
| 324 ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING); | |
| 325 return 0; | |
| 326 } | |
| 327 | |
| 328 if (form == 0) | |
| 329 { | |
| 330 if (len != 1) | |
| 331 { | |
| 332 ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODI
NG); | |
| 333 return 0; | |
| 334 } | |
| 335 | |
| 336 return EC_POINT_set_to_infinity(group, point); | |
| 337 } | |
| 338 | |
| 339 field_len = (EC_GROUP_get_degree(group) + 7) / 8; | |
| 340 enc_len = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*
field_len; | |
| 341 | |
| 342 if (len != enc_len) | |
| 343 { | |
| 344 ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING); | |
| 345 return 0; | |
| 346 } | |
| 347 | |
| 348 if (ctx == NULL) | |
| 349 { | |
| 350 ctx = new_ctx = BN_CTX_new(); | |
| 351 if (ctx == NULL) | |
| 352 return 0; | |
| 353 } | |
| 354 | |
| 355 BN_CTX_start(ctx); | |
| 356 x = BN_CTX_get(ctx); | |
| 357 y = BN_CTX_get(ctx); | |
| 358 yxi = BN_CTX_get(ctx); | |
| 359 if (yxi == NULL) goto err; | |
| 360 | |
| 361 if (!BN_bin2bn(buf + 1, field_len, x)) goto err; | |
| 362 if (BN_ucmp(x, &group->field) >= 0) | |
| 363 { | |
| 364 ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING); | |
| 365 goto err; | |
| 366 } | |
| 367 | |
| 368 if (form == POINT_CONVERSION_COMPRESSED) | |
| 369 { | |
| 370 if (!EC_POINT_set_compressed_coordinates_GF2m(group, point, x, y
_bit, ctx)) goto err; | |
| 371 } | |
| 372 else | |
| 373 { | |
| 374 if (!BN_bin2bn(buf + 1 + field_len, field_len, y)) goto err; | |
| 375 if (BN_ucmp(y, &group->field) >= 0) | |
| 376 { | |
| 377 ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODI
NG); | |
| 378 goto err; | |
| 379 } | |
| 380 if (form == POINT_CONVERSION_HYBRID) | |
| 381 { | |
| 382 if (!group->meth->field_div(group, yxi, y, x, ctx)) goto
err; | |
| 383 if (y_bit != BN_is_odd(yxi)) | |
| 384 { | |
| 385 ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALI
D_ENCODING); | |
| 386 goto err; | |
| 387 } | |
| 388 } | |
| 389 | |
| 390 if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ct
x)) goto err; | |
| 391 } | |
| 392 | |
| 393 if (!EC_POINT_is_on_curve(group, point, ctx)) /* test required by X9.62
*/ | |
| 394 { | |
| 395 ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE)
; | |
| 396 goto err; | |
| 397 } | |
| 398 | |
| 399 ret = 1; | |
| 400 | |
| 401 err: | |
| 402 BN_CTX_end(ctx); | |
| 403 if (new_ctx != NULL) | |
| 404 BN_CTX_free(new_ctx); | |
| 405 return ret; | |
| 406 } | |
| 407 #endif | |
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Issue 2072073002:
Delete bundled copy of OpenSSL and replace with README. (Closed)
Base URL: https://chromium.googlesource.com/chromium/deps/openssl@master