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author | djm <> | 2012-10-13 21:23:50 +0000 |
---|---|---|
committer | djm <> | 2012-10-13 21:23:50 +0000 |
commit | 228cae30b117c2493f69ad3c195341cd6ec8d430 (patch) | |
tree | 29ff00b10d52c0978077c4fd83c33b065bade73e /src/lib/libcrypto/ec/ec2_oct.c | |
parent | 731838c66b52c0ae5888333005b74115a620aa96 (diff) | |
download | openbsd-228cae30b117c2493f69ad3c195341cd6ec8d430.tar.gz openbsd-228cae30b117c2493f69ad3c195341cd6ec8d430.tar.bz2 openbsd-228cae30b117c2493f69ad3c195341cd6ec8d430.zip |
import OpenSSL-1.0.1c
Diffstat (limited to 'src/lib/libcrypto/ec/ec2_oct.c')
-rw-r--r-- | src/lib/libcrypto/ec/ec2_oct.c | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/src/lib/libcrypto/ec/ec2_oct.c b/src/lib/libcrypto/ec/ec2_oct.c new file mode 100644 index 0000000000..f1d75e5ddf --- /dev/null +++ b/src/lib/libcrypto/ec/ec2_oct.c | |||
@@ -0,0 +1,407 @@ | |||
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 *point, | ||
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)) goto 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_COORDINATES, EC_R_INVALID_COMPRESSED_POINT); | ||
136 | } | ||
137 | else | ||
138 | ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, 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, point_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*field_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_SMALL); | ||
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, ctx)) 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_ERROR); | ||
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_ERROR); | ||
252 | goto err; | ||
253 | } | ||
254 | |||
255 | if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVERSION_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_INTERNAL_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_ERROR); | ||
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_ENCODING); | ||
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_ENCODING); | ||
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_INVALID_ENCODING); | ||
386 | goto err; | ||
387 | } | ||
388 | } | ||
389 | |||
390 | if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx)) 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 | ||