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Diffstat (limited to 'src/lib/libssl/src/crypto/ec/ecp_oct.c')
-rw-r--r--src/lib/libssl/src/crypto/ec/ecp_oct.c433
1 files changed, 433 insertions, 0 deletions
diff --git a/src/lib/libssl/src/crypto/ec/ecp_oct.c b/src/lib/libssl/src/crypto/ec/ecp_oct.c
new file mode 100644
index 0000000000..374a0ee731
--- /dev/null
+++ b/src/lib/libssl/src/crypto/ec/ecp_oct.c
@@ -0,0 +1,433 @@
1/* crypto/ec/ecp_oct.c */
2/* Includes code written by Lenka Fibikova <fibikova@exp-math.uni-essen.de>
3 * for the OpenSSL project.
4 * Includes code written by Bodo Moeller for the OpenSSL project.
5*/
6/* ====================================================================
7 * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
19 * distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * openssl-core@openssl.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 * acknowledgment:
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59/* ====================================================================
60 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
61 * Portions of this software developed by SUN MICROSYSTEMS, INC.,
62 * and contributed to the OpenSSL project.
63 */
64
65#include <openssl/err.h>
66#include <openssl/symhacks.h>
67
68#include "ec_lcl.h"
69
70int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *point,
71 const BIGNUM *x_, int y_bit, BN_CTX *ctx)
72 {
73 BN_CTX *new_ctx = NULL;
74 BIGNUM *tmp1, *tmp2, *x, *y;
75 int ret = 0;
76
77 /* clear error queue*/
78 ERR_clear_error();
79
80 if (ctx == NULL)
81 {
82 ctx = new_ctx = BN_CTX_new();
83 if (ctx == NULL)
84 return 0;
85 }
86
87 y_bit = (y_bit != 0);
88
89 BN_CTX_start(ctx);
90 tmp1 = BN_CTX_get(ctx);
91 tmp2 = BN_CTX_get(ctx);
92 x = BN_CTX_get(ctx);
93 y = BN_CTX_get(ctx);
94 if (y == NULL) goto err;
95
96 /* Recover y. We have a Weierstrass equation
97 * y^2 = x^3 + a*x + b,
98 * so y is one of the square roots of x^3 + a*x + b.
99 */
100
101 /* tmp1 := x^3 */
102 if (!BN_nnmod(x, x_, &group->field,ctx)) goto err;
103 if (group->meth->field_decode == 0)
104 {
105 /* field_{sqr,mul} work on standard representation */
106 if (!group->meth->field_sqr(group, tmp2, x_, ctx)) goto err;
107 if (!group->meth->field_mul(group, tmp1, tmp2, x_, ctx)) goto err;
108 }
109 else
110 {
111 if (!BN_mod_sqr(tmp2, x_, &group->field, ctx)) goto err;
112 if (!BN_mod_mul(tmp1, tmp2, x_, &group->field, ctx)) goto err;
113 }
114
115 /* tmp1 := tmp1 + a*x */
116 if (group->a_is_minus3)
117 {
118 if (!BN_mod_lshift1_quick(tmp2, x, &group->field)) goto err;
119 if (!BN_mod_add_quick(tmp2, tmp2, x, &group->field)) goto err;
120 if (!BN_mod_sub_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
121 }
122 else
123 {
124 if (group->meth->field_decode)
125 {
126 if (!group->meth->field_decode(group, tmp2, &group->a, ctx)) goto err;
127 if (!BN_mod_mul(tmp2, tmp2, x, &group->field, ctx)) goto err;
128 }
129 else
130 {
131 /* field_mul works on standard representation */
132 if (!group->meth->field_mul(group, tmp2, &group->a, x, ctx)) goto err;
133 }
134
135 if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
136 }
137
138 /* tmp1 := tmp1 + b */
139 if (group->meth->field_decode)
140 {
141 if (!group->meth->field_decode(group, tmp2, &group->b, ctx)) goto err;
142 if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
143 }
144 else
145 {
146 if (!BN_mod_add_quick(tmp1, tmp1, &group->b, &group->field)) goto err;
147 }
148
149 if (!BN_mod_sqrt(y, tmp1, &group->field, ctx))
150 {
151 unsigned long err = ERR_peek_last_error();
152
153 if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err) == BN_R_NOT_A_SQUARE)
154 {
155 ERR_clear_error();
156 ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);
157 }
158 else
159 ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_BN_LIB);
160 goto err;
161 }
162
163 if (y_bit != BN_is_odd(y))
164 {
165 if (BN_is_zero(y))
166 {
167 int kron;
168
169 kron = BN_kronecker(x, &group->field, ctx);
170 if (kron == -2) goto err;
171
172 if (kron == 1)
173 ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSION_BIT);
174 else
175 /* BN_mod_sqrt() should have cought this error (not a square) */
176 ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);
177 goto err;
178 }
179 if (!BN_usub(y, &group->field, y)) goto err;
180 }
181 if (y_bit != BN_is_odd(y))
182 {
183 ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_INTERNAL_ERROR);
184 goto err;
185 }
186
187 if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
188
189 ret = 1;
190
191 err:
192 BN_CTX_end(ctx);
193 if (new_ctx != NULL)
194 BN_CTX_free(new_ctx);
195 return ret;
196 }
197
198
199size_t ec_GFp_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, point_conversion_form_t form,
200 unsigned char *buf, size_t len, BN_CTX *ctx)
201 {
202 size_t ret;
203 BN_CTX *new_ctx = NULL;
204 int used_ctx = 0;
205 BIGNUM *x, *y;
206 size_t field_len, i, skip;
207
208 if ((form != POINT_CONVERSION_COMPRESSED)
209 && (form != POINT_CONVERSION_UNCOMPRESSED)
210 && (form != POINT_CONVERSION_HYBRID))
211 {
212 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_INVALID_FORM);
213 goto err;
214 }
215
216 if (EC_POINT_is_at_infinity(group, point))
217 {
218 /* encodes to a single 0 octet */
219 if (buf != NULL)
220 {
221 if (len < 1)
222 {
223 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
224 return 0;
225 }
226 buf[0] = 0;
227 }
228 return 1;
229 }
230
231
232 /* ret := required output buffer length */
233 field_len = BN_num_bytes(&group->field);
234 ret = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
235
236 /* if 'buf' is NULL, just return required length */
237 if (buf != NULL)
238 {
239 if (len < ret)
240 {
241 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
242 goto err;
243 }
244
245 if (ctx == NULL)
246 {
247 ctx = new_ctx = BN_CTX_new();
248 if (ctx == NULL)
249 return 0;
250 }
251
252 BN_CTX_start(ctx);
253 used_ctx = 1;
254 x = BN_CTX_get(ctx);
255 y = BN_CTX_get(ctx);
256 if (y == NULL) goto err;
257
258 if (!EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
259
260 if ((form == POINT_CONVERSION_COMPRESSED || form == POINT_CONVERSION_HYBRID) && BN_is_odd(y))
261 buf[0] = form + 1;
262 else
263 buf[0] = form;
264
265 i = 1;
266
267 skip = field_len - BN_num_bytes(x);
268 if (skip > field_len)
269 {
270 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
271 goto err;
272 }
273 while (skip > 0)
274 {
275 buf[i++] = 0;
276 skip--;
277 }
278 skip = BN_bn2bin(x, buf + i);
279 i += skip;
280 if (i != 1 + field_len)
281 {
282 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
283 goto err;
284 }
285
286 if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVERSION_HYBRID)
287 {
288 skip = field_len - BN_num_bytes(y);
289 if (skip > field_len)
290 {
291 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
292 goto err;
293 }
294 while (skip > 0)
295 {
296 buf[i++] = 0;
297 skip--;
298 }
299 skip = BN_bn2bin(y, buf + i);
300 i += skip;
301 }
302
303 if (i != ret)
304 {
305 ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
306 goto err;
307 }
308 }
309
310 if (used_ctx)
311 BN_CTX_end(ctx);
312 if (new_ctx != NULL)
313 BN_CTX_free(new_ctx);
314 return ret;
315
316 err:
317 if (used_ctx)
318 BN_CTX_end(ctx);
319 if (new_ctx != NULL)
320 BN_CTX_free(new_ctx);
321 return 0;
322 }
323
324
325int ec_GFp_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
326 const unsigned char *buf, size_t len, BN_CTX *ctx)
327 {
328 point_conversion_form_t form;
329 int y_bit;
330 BN_CTX *new_ctx = NULL;
331 BIGNUM *x, *y;
332 size_t field_len, enc_len;
333 int ret = 0;
334
335 if (len == 0)
336 {
337 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL);
338 return 0;
339 }
340 form = buf[0];
341 y_bit = form & 1;
342 form = form & ~1U;
343 if ((form != 0) && (form != POINT_CONVERSION_COMPRESSED)
344 && (form != POINT_CONVERSION_UNCOMPRESSED)
345 && (form != POINT_CONVERSION_HYBRID))
346 {
347 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
348 return 0;
349 }
350 if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit)
351 {
352 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
353 return 0;
354 }
355
356 if (form == 0)
357 {
358 if (len != 1)
359 {
360 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
361 return 0;
362 }
363
364 return EC_POINT_set_to_infinity(group, point);
365 }
366
367 field_len = BN_num_bytes(&group->field);
368 enc_len = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
369
370 if (len != enc_len)
371 {
372 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
373 return 0;
374 }
375
376 if (ctx == NULL)
377 {
378 ctx = new_ctx = BN_CTX_new();
379 if (ctx == NULL)
380 return 0;
381 }
382
383 BN_CTX_start(ctx);
384 x = BN_CTX_get(ctx);
385 y = BN_CTX_get(ctx);
386 if (y == NULL) goto err;
387
388 if (!BN_bin2bn(buf + 1, field_len, x)) goto err;
389 if (BN_ucmp(x, &group->field) >= 0)
390 {
391 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
392 goto err;
393 }
394
395 if (form == POINT_CONVERSION_COMPRESSED)
396 {
397 if (!EC_POINT_set_compressed_coordinates_GFp(group, point, x, y_bit, ctx)) goto err;
398 }
399 else
400 {
401 if (!BN_bin2bn(buf + 1 + field_len, field_len, y)) goto err;
402 if (BN_ucmp(y, &group->field) >= 0)
403 {
404 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
405 goto err;
406 }
407 if (form == POINT_CONVERSION_HYBRID)
408 {
409 if (y_bit != BN_is_odd(y))
410 {
411 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
412 goto err;
413 }
414 }
415
416 if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
417 }
418
419 if (!EC_POINT_is_on_curve(group, point, ctx)) /* test required by X9.62 */
420 {
421 ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);
422 goto err;
423 }
424
425 ret = 1;
426
427 err:
428 BN_CTX_end(ctx);
429 if (new_ctx != NULL)
430 BN_CTX_free(new_ctx);
431 return ret;
432 }
433
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