source: EcnlProtoTool/trunk/openssl-1.1.0e/crypto/ec/ecp_oct.c@ 331

Last change on this file since 331 was 331, checked in by coas-nagasima, 6 years ago

prototoolに関連するプロジェクトをnewlibからmuslを使うよう変更・更新
ntshellをnewlibの下位の実装から、muslのsyscallの実装に変更・更新
以下のOSSをアップデート
・mruby-1.3.0
・musl-1.1.18
・onigmo-6.1.3
・tcc-0.9.27
以下のOSSを追加
・openssl-1.1.0e
・curl-7.57.0
・zlib-1.2.11
以下のmrbgemsを追加
・iij/mruby-digest
・iij/mruby-env
・iij/mruby-errno
・iij/mruby-iijson
・iij/mruby-ipaddr
・iij/mruby-mock
・iij/mruby-require
・iij/mruby-tls-openssl
  • Property svn:eol-style set to native
  • Property svn:mime-type set to text/x-csrc
File size: 10.4 KB
Line 
1/*
2 * Copyright 2011-2016 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10/* ====================================================================
11 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
12 * Portions of this software developed by SUN MICROSYSTEMS, INC.,
13 * and contributed to the OpenSSL project.
14 */
15
16#include <openssl/err.h>
17#include <openssl/symhacks.h>
18
19#include "ec_lcl.h"
20
21int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *group,
22 EC_POINT *point,
23 const BIGNUM *x_, int y_bit,
24 BN_CTX *ctx)
25{
26 BN_CTX *new_ctx = NULL;
27 BIGNUM *tmp1, *tmp2, *x, *y;
28 int ret = 0;
29
30 /* clear error queue */
31 ERR_clear_error();
32
33 if (ctx == NULL) {
34 ctx = new_ctx = BN_CTX_new();
35 if (ctx == NULL)
36 return 0;
37 }
38
39 y_bit = (y_bit != 0);
40
41 BN_CTX_start(ctx);
42 tmp1 = BN_CTX_get(ctx);
43 tmp2 = BN_CTX_get(ctx);
44 x = BN_CTX_get(ctx);
45 y = BN_CTX_get(ctx);
46 if (y == NULL)
47 goto err;
48
49 /*-
50 * Recover y. We have a Weierstrass equation
51 * y^2 = x^3 + a*x + b,
52 * so y is one of the square roots of x^3 + a*x + b.
53 */
54
55 /* tmp1 := x^3 */
56 if (!BN_nnmod(x, x_, group->field, ctx))
57 goto err;
58 if (group->meth->field_decode == 0) {
59 /* field_{sqr,mul} work on standard representation */
60 if (!group->meth->field_sqr(group, tmp2, x_, ctx))
61 goto err;
62 if (!group->meth->field_mul(group, tmp1, tmp2, x_, ctx))
63 goto err;
64 } else {
65 if (!BN_mod_sqr(tmp2, x_, group->field, ctx))
66 goto err;
67 if (!BN_mod_mul(tmp1, tmp2, x_, group->field, ctx))
68 goto err;
69 }
70
71 /* tmp1 := tmp1 + a*x */
72 if (group->a_is_minus3) {
73 if (!BN_mod_lshift1_quick(tmp2, x, group->field))
74 goto err;
75 if (!BN_mod_add_quick(tmp2, tmp2, x, group->field))
76 goto err;
77 if (!BN_mod_sub_quick(tmp1, tmp1, tmp2, group->field))
78 goto err;
79 } else {
80 if (group->meth->field_decode) {
81 if (!group->meth->field_decode(group, tmp2, group->a, ctx))
82 goto err;
83 if (!BN_mod_mul(tmp2, tmp2, x, group->field, ctx))
84 goto err;
85 } else {
86 /* field_mul works on standard representation */
87 if (!group->meth->field_mul(group, tmp2, group->a, x, ctx))
88 goto err;
89 }
90
91 if (!BN_mod_add_quick(tmp1, tmp1, tmp2, group->field))
92 goto err;
93 }
94
95 /* tmp1 := tmp1 + b */
96 if (group->meth->field_decode) {
97 if (!group->meth->field_decode(group, tmp2, group->b, ctx))
98 goto err;
99 if (!BN_mod_add_quick(tmp1, tmp1, tmp2, group->field))
100 goto err;
101 } else {
102 if (!BN_mod_add_quick(tmp1, tmp1, group->b, group->field))
103 goto err;
104 }
105
106 if (!BN_mod_sqrt(y, tmp1, group->field, ctx)) {
107 unsigned long err = ERR_peek_last_error();
108
109 if (ERR_GET_LIB(err) == ERR_LIB_BN
110 && ERR_GET_REASON(err) == BN_R_NOT_A_SQUARE) {
111 ERR_clear_error();
112 ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES,
113 EC_R_INVALID_COMPRESSED_POINT);
114 } else
115 ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES,
116 ERR_R_BN_LIB);
117 goto err;
118 }
119
120 if (y_bit != BN_is_odd(y)) {
121 if (BN_is_zero(y)) {
122 int kron;
123
124 kron = BN_kronecker(x, group->field, ctx);
125 if (kron == -2)
126 goto err;
127
128 if (kron == 1)
129 ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES,
130 EC_R_INVALID_COMPRESSION_BIT);
131 else
132 /*
133 * BN_mod_sqrt() should have cought this error (not a square)
134 */
135 ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES,
136 EC_R_INVALID_COMPRESSED_POINT);
137 goto err;
138 }
139 if (!BN_usub(y, group->field, y))
140 goto err;
141 }
142 if (y_bit != BN_is_odd(y)) {
143 ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES,
144 ERR_R_INTERNAL_ERROR);
145 goto err;
146 }
147
148 if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx))
149 goto err;
150
151 ret = 1;
152
153 err:
154 BN_CTX_end(ctx);
155 BN_CTX_free(new_ctx);
156 return ret;
157}
158
159size_t ec_GFp_simple_point2oct(const EC_GROUP *group, const EC_POINT *point,
160 point_conversion_form_t form,
161 unsigned char *buf, size_t len, BN_CTX *ctx)
162{
163 size_t ret;
164 BN_CTX *new_ctx = NULL;
165 int used_ctx = 0;
166 BIGNUM *x, *y;
167 size_t field_len, i, skip;
168
169 if ((form != POINT_CONVERSION_COMPRESSED)
170 && (form != POINT_CONVERSION_UNCOMPRESSED)
171 && (form != POINT_CONVERSION_HYBRID)) {
172 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_INVALID_FORM);
173 goto err;
174 }
175
176 if (EC_POINT_is_at_infinity(group, point)) {
177 /* encodes to a single 0 octet */
178 if (buf != NULL) {
179 if (len < 1) {
180 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
181 return 0;
182 }
183 buf[0] = 0;
184 }
185 return 1;
186 }
187
188 /* ret := required output buffer length */
189 field_len = BN_num_bytes(group->field);
190 ret =
191 (form ==
192 POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2 * field_len;
193
194 /* if 'buf' is NULL, just return required length */
195 if (buf != NULL) {
196 if (len < ret) {
197 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
198 goto err;
199 }
200
201 if (ctx == NULL) {
202 ctx = new_ctx = BN_CTX_new();
203 if (ctx == NULL)
204 return 0;
205 }
206
207 BN_CTX_start(ctx);
208 used_ctx = 1;
209 x = BN_CTX_get(ctx);
210 y = BN_CTX_get(ctx);
211 if (y == NULL)
212 goto err;
213
214 if (!EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx))
215 goto err;
216
217 if ((form == POINT_CONVERSION_COMPRESSED
218 || form == POINT_CONVERSION_HYBRID) && BN_is_odd(y))
219 buf[0] = form + 1;
220 else
221 buf[0] = form;
222
223 i = 1;
224
225 skip = field_len - BN_num_bytes(x);
226 if (skip > field_len) {
227 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
228 goto err;
229 }
230 while (skip > 0) {
231 buf[i++] = 0;
232 skip--;
233 }
234 skip = BN_bn2bin(x, buf + i);
235 i += skip;
236 if (i != 1 + field_len) {
237 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
238 goto err;
239 }
240
241 if (form == POINT_CONVERSION_UNCOMPRESSED
242 || form == POINT_CONVERSION_HYBRID) {
243 skip = field_len - BN_num_bytes(y);
244 if (skip > field_len) {
245 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
246 goto err;
247 }
248 while (skip > 0) {
249 buf[i++] = 0;
250 skip--;
251 }
252 skip = BN_bn2bin(y, buf + i);
253 i += skip;
254 }
255
256 if (i != ret) {
257 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
258 goto err;
259 }
260 }
261
262 if (used_ctx)
263 BN_CTX_end(ctx);
264 BN_CTX_free(new_ctx);
265 return ret;
266
267 err:
268 if (used_ctx)
269 BN_CTX_end(ctx);
270 BN_CTX_free(new_ctx);
271 return 0;
272}
273
274int ec_GFp_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
275 const unsigned char *buf, size_t len, BN_CTX *ctx)
276{
277 point_conversion_form_t form;
278 int y_bit;
279 BN_CTX *new_ctx = NULL;
280 BIGNUM *x, *y;
281 size_t field_len, enc_len;
282 int ret = 0;
283
284 if (len == 0) {
285 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL);
286 return 0;
287 }
288 form = buf[0];
289 y_bit = form & 1;
290 form = form & ~1U;
291 if ((form != 0) && (form != POINT_CONVERSION_COMPRESSED)
292 && (form != POINT_CONVERSION_UNCOMPRESSED)
293 && (form != POINT_CONVERSION_HYBRID)) {
294 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
295 return 0;
296 }
297 if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit) {
298 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
299 return 0;
300 }
301
302 if (form == 0) {
303 if (len != 1) {
304 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
305 return 0;
306 }
307
308 return EC_POINT_set_to_infinity(group, point);
309 }
310
311 field_len = BN_num_bytes(group->field);
312 enc_len =
313 (form ==
314 POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2 * field_len;
315
316 if (len != enc_len) {
317 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
318 return 0;
319 }
320
321 if (ctx == NULL) {
322 ctx = new_ctx = BN_CTX_new();
323 if (ctx == NULL)
324 return 0;
325 }
326
327 BN_CTX_start(ctx);
328 x = BN_CTX_get(ctx);
329 y = BN_CTX_get(ctx);
330 if (y == NULL)
331 goto err;
332
333 if (!BN_bin2bn(buf + 1, field_len, x))
334 goto err;
335 if (BN_ucmp(x, group->field) >= 0) {
336 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
337 goto err;
338 }
339
340 if (form == POINT_CONVERSION_COMPRESSED) {
341 if (!EC_POINT_set_compressed_coordinates_GFp
342 (group, point, x, y_bit, ctx))
343 goto err;
344 } else {
345 if (!BN_bin2bn(buf + 1 + field_len, field_len, y))
346 goto err;
347 if (BN_ucmp(y, group->field) >= 0) {
348 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
349 goto err;
350 }
351 if (form == POINT_CONVERSION_HYBRID) {
352 if (y_bit != BN_is_odd(y)) {
353 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
354 goto err;
355 }
356 }
357
358 /*
359 * EC_POINT_set_affine_coordinates_GFp is responsible for checking that
360 * the point is on the curve.
361 */
362 if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx))
363 goto err;
364 }
365
366 ret = 1;
367
368 err:
369 BN_CTX_end(ctx);
370 BN_CTX_free(new_ctx);
371 return ret;
372}
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