1 /* Originally written by Bodo Moeller for the OpenSSL project.
2  * ====================================================================
3  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in
14  *    the documentation and/or other materials provided with the
15  *    distribution.
16  *
17  * 3. All advertising materials mentioning features or use of this
18  *    software must display the following acknowledgment:
19  *    "This product includes software developed by the OpenSSL Project
20  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
21  *
22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23  *    endorse or promote products derived from this software without
24  *    prior written permission. For written permission, please contact
25  *    openssl-core@openssl.org.
26  *
27  * 5. Products derived from this software may not be called "OpenSSL"
28  *    nor may "OpenSSL" appear in their names without prior written
29  *    permission of the OpenSSL Project.
30  *
31  * 6. Redistributions of any form whatsoever must retain the following
32  *    acknowledgment:
33  *    "This product includes software developed by the OpenSSL Project
34  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35  *
36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47  * OF THE POSSIBILITY OF SUCH DAMAGE.
48  * ====================================================================
49  *
50  * This product includes cryptographic software written by Eric Young
51  * (eay@cryptsoft.com).  This product includes software written by Tim
52  * Hudson (tjh@cryptsoft.com).
53  *
54  */
55 /* ====================================================================
56  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
57  *
58  * Portions of the attached software ("Contribution") are developed by
59  * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
60  *
61  * The Contribution is licensed pursuant to the OpenSSL open source
62  * license provided above.
63  *
64  * The elliptic curve binary polynomial software is originally written by
65  * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems
66  * Laboratories. */
67 
68 #ifndef OPENSSL_HEADER_EC_H
69 #define OPENSSL_HEADER_EC_H
70 
71 #include <openssl/base.h>
72 
73 #if defined(__cplusplus)
74 extern "C" {
75 #endif
76 
77 
78 /* Low-level operations on elliptic curves. */
79 
80 
81 typedef struct ec_group_st EC_GROUP;
82 typedef struct ec_point_st EC_POINT;
83 
84 /** Enum for the point conversion form as defined in X9.62 (ECDSA)
85  *  for the encoding of a elliptic curve point (x,y) */
86 typedef enum {
87 	/** the point is encoded as z||x, where the octet z specifies
88 	 *  which solution of the quadratic equation y is  */
89 	POINT_CONVERSION_COMPRESSED = 2,
90 	/** the point is encoded as z||x||y, where z is the octet 0x02  */
91 	POINT_CONVERSION_UNCOMPRESSED = 4
92 } point_conversion_form_t;
93 
94 
95 /* Elliptic curve groups. */
96 
97 /* EC_GROUP_new_by_curve_name returns a fresh EC_GROUP object for the elliptic
98  * curve specified by |nid|, or NULL on error.
99  *
100  * The supported NIDs are:
101  *   NID_secp224r1,
102  *   NID_X9_62_prime256v1,
103  *   NID_secp384r1,
104  *   NID_secp521r1 */
105 OPENSSL_EXPORT EC_GROUP *EC_GROUP_new_by_curve_name(int nid);
106 
107 /* EC_GROUP_free frees |group| and the data that it points to. */
108 OPENSSL_EXPORT void EC_GROUP_free(EC_GROUP *group);
109 
110 /* EC_GROUP_dup returns a fresh |EC_GROUP| which is equal to |a| or NULL on
111  * error. */
112 OPENSSL_EXPORT EC_GROUP *EC_GROUP_dup(const EC_GROUP *a);
113 
114 /* EC_GROUP_cmp returns zero if |a| and |b| are the same group and non-zero
115  * otherwise. */
116 OPENSSL_EXPORT int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b,
117                                 BN_CTX *ignored);
118 
119 /* EC_GROUP_get0_generator returns a pointer to the internal |EC_POINT| object
120  * in |group| that specifies the generator for the group. */
121 OPENSSL_EXPORT const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group);
122 
123 /* EC_GROUP_get_order sets |*order| to the order of |group|, if it's not
124  * NULL. It returns one on success and zero otherwise. |ctx| is ignored. */
125 OPENSSL_EXPORT int EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order,
126                                       BN_CTX *ctx);
127 
128 /* EC_GROUP_get_cofactor sets |*cofactor| to the cofactor of |group| using
129  * |ctx|, if it's not NULL. It returns one on success and zero otherwise. */
130 OPENSSL_EXPORT int EC_GROUP_get_cofactor(const EC_GROUP *group,
131                                          BIGNUM *cofactor, BN_CTX *ctx);
132 
133 /* EC_GROUP_get_curve_GFp gets various parameters about a group. It sets
134  * |*out_p| to the order of the coordinate field and |*out_a| and |*out_b| to
135  * the parameters of the curve when expressed as y² = x³ + ax + b. Any of the
136  * output parameters can be NULL. It returns one on success and zero on
137  * error. */
138 OPENSSL_EXPORT int EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *out_p,
139                                           BIGNUM *out_a, BIGNUM *out_b,
140                                           BN_CTX *ctx);
141 
142 /* EC_GROUP_get_curve_name returns a NID that identifies |group|. */
143 OPENSSL_EXPORT int EC_GROUP_get_curve_name(const EC_GROUP *group);
144 
145 /* EC_GROUP_get_degree returns the number of bits needed to represent an
146  * element of the field underlying |group|. */
147 OPENSSL_EXPORT int EC_GROUP_get_degree(const EC_GROUP *group);
148 
149 /* EC_GROUP_precompute_mult precomputes multiplies of the generator in order to
150  * speed up operations that involve calculating generator multiples. It returns
151  * one on sucess and zero otherwise. If |ctx| is not NULL, it may be used. */
152 OPENSSL_EXPORT int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
153 
154 /* EC_GROUP_have_precompute_mult returns one if |group| contains precomputed
155  * generator multiples. */
156 OPENSSL_EXPORT int EC_GROUP_have_precompute_mult(const EC_GROUP *group);
157 
158 
159 /* Points on elliptic curves. */
160 
161 /* EC_POINT_new returns a fresh |EC_POINT| object in the given group, or NULL
162  * on error. */
163 OPENSSL_EXPORT EC_POINT *EC_POINT_new(const EC_GROUP *group);
164 
165 /* EC_POINT_free frees |point| and the data that it points to. */
166 OPENSSL_EXPORT void EC_POINT_free(EC_POINT *point);
167 
168 /* EC_POINT_clear_free clears the data that |point| points to, frees it and
169  * then frees |point| itself. */
170 OPENSSL_EXPORT void EC_POINT_clear_free(EC_POINT *point);
171 
172 /* EC_POINT_copy sets |*dest| equal to |*src|. It returns one on success and
173  * zero otherwise. */
174 OPENSSL_EXPORT int EC_POINT_copy(EC_POINT *dest, const EC_POINT *src);
175 
176 /* EC_POINT_dup returns a fresh |EC_POINT| that contains the same values as
177  * |src|, or NULL on error. */
178 OPENSSL_EXPORT EC_POINT *EC_POINT_dup(const EC_POINT *src,
179                                       const EC_GROUP *group);
180 
181 /* EC_POINT_set_to_infinity sets |point| to be the "point at infinity" for the
182  * given group. */
183 OPENSSL_EXPORT int EC_POINT_set_to_infinity(const EC_GROUP *group,
184                                             EC_POINT *point);
185 
186 /* EC_POINT_is_at_infinity returns one iff |point| is the point at infinity and
187  * zero otherwise. */
188 OPENSSL_EXPORT int EC_POINT_is_at_infinity(const EC_GROUP *group,
189                                            const EC_POINT *point);
190 
191 /* EC_POINT_is_on_curve returns one if |point| is an element of |group| and
192  * zero otheriwse. If |ctx| is non-NULL, it may be used. */
193 OPENSSL_EXPORT int EC_POINT_is_on_curve(const EC_GROUP *group,
194                                         const EC_POINT *point, BN_CTX *ctx);
195 
196 /* EC_POINT_cmp returns zero if |a| is equal to |b|, greater than zero is
197  * non-equal and -1 on error. If |ctx| is not NULL, it may be used. */
198 OPENSSL_EXPORT int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a,
199                                 const EC_POINT *b, BN_CTX *ctx);
200 
201 /* EC_POINT_make_affine converts |point| to affine form, internally. It returns
202  * one on success and zero otherwise. If |ctx| is not NULL, it may be used. */
203 OPENSSL_EXPORT int EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point,
204                                         BN_CTX *ctx);
205 
206 /* EC_POINTs_make_affine converts |num| points from |points| to affine form,
207  * internally. It returns one on success and zero otherwise. If |ctx| is not
208  * NULL, it may be used. */
209 OPENSSL_EXPORT int EC_POINTs_make_affine(const EC_GROUP *group, size_t num,
210                                          EC_POINT *points[], BN_CTX *ctx);
211 
212 
213 /* Point conversion. */
214 
215 /* EC_POINT_get_affine_coordinates_GFp sets |x| and |y| to the affine value of
216  * |point| using |ctx|, if it's not NULL. It returns one on success and zero
217  * otherwise. */
218 OPENSSL_EXPORT int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group,
219                                                        const EC_POINT *point,
220                                                        BIGNUM *x, BIGNUM *y,
221                                                        BN_CTX *ctx);
222 
223 /* EC_POINT_set_affine_coordinates sets the value of |p| to be (|x|, |y|). The
224  * |ctx| argument may be used if not NULL. */
225 OPENSSL_EXPORT int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group,
226                                                        EC_POINT *point,
227                                                        const BIGNUM *x,
228                                                        const BIGNUM *y,
229                                                        BN_CTX *ctx);
230 
231 /* EC_POINT_point2oct serialises |point| into the X9.62 form given by |form|
232  * into, at most, |len| bytes at |buf|. It returns the number of bytes written
233  * or zero on error if |buf| is non-NULL, else the number of bytes needed. The
234  * |ctx| argument may be used if not NULL. */
235 OPENSSL_EXPORT size_t EC_POINT_point2oct(const EC_GROUP *group,
236                                          const EC_POINT *point,
237                                          point_conversion_form_t form,
238                                          uint8_t *buf, size_t len, BN_CTX *ctx);
239 
240 /* EC_POINT_oct2point sets |point| from |len| bytes of X9.62 format
241  * serialisation in |buf|. It returns one on success and zero otherwise. The
242  * |ctx| argument may be used if not NULL. */
243 OPENSSL_EXPORT int EC_POINT_oct2point(const EC_GROUP *group, EC_POINT *point,
244                                       const uint8_t *buf, size_t len,
245                                       BN_CTX *ctx);
246 
247 /* EC_POINT_set_compressed_coordinates_GFp sets |point| to equal the point with
248  * the given |x| coordinate and the y coordinate specified by |y_bit| (see
249  * X9.62). It returns one on success and zero otherwise. */
250 OPENSSL_EXPORT int EC_POINT_set_compressed_coordinates_GFp(
251     const EC_GROUP *group, EC_POINT *point, const BIGNUM *x, int y_bit,
252     BN_CTX *ctx);
253 
254 
255 /* Group operations. */
256 
257 /* EC_POINT_add sets |r| equal to |a| plus |b|. It returns one on success and
258  * zero otherwise. If |ctx| is not NULL, it may be used. */
259 OPENSSL_EXPORT int EC_POINT_add(const EC_GROUP *group, EC_POINT *r,
260                                 const EC_POINT *a, const EC_POINT *b,
261                                 BN_CTX *ctx);
262 
263 /* EC_POINT_dbl sets |r| equal to |a| plus |a|. It returns one on success and
264  * zero otherwise. If |ctx| is not NULL, it may be used. */
265 OPENSSL_EXPORT int EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r,
266                                 const EC_POINT *a, BN_CTX *ctx);
267 
268 /* EC_POINT_dbl sets |a| equal to minus |a|. It returns one on success and zero
269  * otherwise. If |ctx| is not NULL, it may be used. */
270 OPENSSL_EXPORT int EC_POINT_invert(const EC_GROUP *group, EC_POINT *a,
271                                    BN_CTX *ctx);
272 
273 /* EC_POINT_mul sets r = generator*n + q*m. It returns one on success and zero
274  * otherwise. If |ctx| is not NULL, it may be used. */
275 OPENSSL_EXPORT int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r,
276                                 const BIGNUM *n, const EC_POINT *q,
277                                 const BIGNUM *m, BN_CTX *ctx);
278 
279 /* EC_POINTs_mul sets r = generator*n + sum(p[i]*m[i]). It returns one on
280  * success and zero otherwise. If |ctx| is not NULL, it may be used. */
281 OPENSSL_EXPORT int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r,
282                                  const BIGNUM *n, size_t num,
283                                  const EC_POINT *p[], const BIGNUM *m[],
284                                  BN_CTX *ctx);
285 
286 
287 /* Deprecated functions. */
288 
289 /* EC_GROUP_new_curve_GFp creates a new, arbitrary elliptic curve group based
290  * on the equation y² = x³ + a·x + b. It returns the new group or NULL on
291  * error.
292  *
293  * |EC_GROUP|s returned by this function will always compare as unequal via
294  * |EC_GROUP_cmp| (even to themselves). |EC_GROUP_get_curve_name| will always
295  * return |NID_undef|. */
296 OPENSSL_EXPORT EC_GROUP *EC_GROUP_new_curve_GFp(const BIGNUM *p,
297                                                 const BIGNUM *a,
298                                                 const BIGNUM *b, BN_CTX *ctx);
299 
300 /* EC_GROUP_set_generator sets the generator for |group| to |generator|, which
301  * must have the given order and cofactor. This should only be used with
302  * |EC_GROUP| objects returned by |EC_GROUP_new_curve_GFp|. */
303 OPENSSL_EXPORT int EC_GROUP_set_generator(EC_GROUP *group,
304                                           const EC_POINT *generator,
305                                           const BIGNUM *order,
306                                           const BIGNUM *cofactor);
307 
308 /* EC_GROUP_set_asn1_flag does nothing. */
309 OPENSSL_EXPORT void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag);
310 
311 #define OPENSSL_EC_NAMED_CURVE 0
312 
313 typedef struct ec_method_st EC_METHOD;
314 
315 /* EC_GROUP_method_of returns NULL. */
316 OPENSSL_EXPORT const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *group);
317 
318 /* EC_METHOD_get_field_type returns NID_X9_62_prime_field. */
319 OPENSSL_EXPORT int EC_METHOD_get_field_type(const EC_METHOD *meth);
320 
321 /* EC_GROUP_set_point_conversion_form aborts the process if |form| is not
322  * |POINT_CONVERSION_UNCOMPRESSED| and otherwise does nothing. */
323 OPENSSL_EXPORT void EC_GROUP_set_point_conversion_form(
324     EC_GROUP *group, point_conversion_form_t form);
325 
326 
327 /* Old code expects to get EC_KEY from ec.h. */
328 #if !defined(OPENSSL_HEADER_EC_KEY_H)
329 #include <openssl/ec_key.h>
330 #endif
331 
332 
333 #if defined(__cplusplus)
334 }  /* extern C */
335 #endif
336 
337 #define EC_F_EC_GROUP_copy 100
338 #define EC_F_EC_GROUP_get_curve_GFp 101
339 #define EC_F_EC_GROUP_get_degree 102
340 #define EC_F_EC_GROUP_new_by_curve_name 103
341 #define EC_F_EC_KEY_check_key 104
342 #define EC_F_EC_KEY_copy 105
343 #define EC_F_EC_KEY_generate_key 106
344 #define EC_F_EC_KEY_new_method 107
345 #define EC_F_EC_KEY_set_public_key_affine_coordinates 108
346 #define EC_F_EC_POINT_add 109
347 #define EC_F_EC_POINT_cmp 110
348 #define EC_F_EC_POINT_copy 111
349 #define EC_F_EC_POINT_dbl 112
350 #define EC_F_EC_POINT_dup 113
351 #define EC_F_EC_POINT_get_affine_coordinates_GFp 114
352 #define EC_F_EC_POINT_invert 115
353 #define EC_F_EC_POINT_is_at_infinity 116
354 #define EC_F_EC_POINT_is_on_curve 117
355 #define EC_F_EC_POINT_make_affine 118
356 #define EC_F_EC_POINT_new 119
357 #define EC_F_EC_POINT_oct2point 120
358 #define EC_F_EC_POINT_point2oct 121
359 #define EC_F_EC_POINT_set_affine_coordinates_GFp 122
360 #define EC_F_EC_POINT_set_compressed_coordinates_GFp 123
361 #define EC_F_EC_POINT_set_to_infinity 124
362 #define EC_F_EC_POINTs_make_affine 125
363 #define EC_F_compute_wNAF 126
364 #define EC_F_d2i_ECPKParameters 127
365 #define EC_F_d2i_ECParameters 128
366 #define EC_F_d2i_ECPrivateKey 129
367 #define EC_F_ec_GFp_mont_field_decode 130
368 #define EC_F_ec_GFp_mont_field_encode 131
369 #define EC_F_ec_GFp_mont_field_mul 132
370 #define EC_F_ec_GFp_mont_field_set_to_one 133
371 #define EC_F_ec_GFp_mont_field_sqr 134
372 #define EC_F_ec_GFp_mont_group_set_curve 135
373 #define EC_F_ec_GFp_simple_group_check_discriminant 136
374 #define EC_F_ec_GFp_simple_group_set_curve 137
375 #define EC_F_ec_GFp_simple_make_affine 138
376 #define EC_F_ec_GFp_simple_oct2point 139
377 #define EC_F_ec_GFp_simple_point2oct 140
378 #define EC_F_ec_GFp_simple_point_get_affine_coordinates 141
379 #define EC_F_ec_GFp_simple_point_set_affine_coordinates 142
380 #define EC_F_ec_GFp_simple_points_make_affine 143
381 #define EC_F_ec_GFp_simple_set_compressed_coordinates 144
382 #define EC_F_ec_asn1_group2pkparameters 145
383 #define EC_F_ec_asn1_pkparameters2group 146
384 #define EC_F_ec_group_new 147
385 #define EC_F_ec_group_new_curve_GFp 148
386 #define EC_F_ec_group_new_from_data 149
387 #define EC_F_ec_point_set_Jprojective_coordinates_GFp 150
388 #define EC_F_ec_pre_comp_new 151
389 #define EC_F_ec_wNAF_mul 152
390 #define EC_F_ec_wNAF_precompute_mult 153
391 #define EC_F_i2d_ECPKParameters 154
392 #define EC_F_i2d_ECParameters 155
393 #define EC_F_i2d_ECPrivateKey 156
394 #define EC_F_i2o_ECPublicKey 157
395 #define EC_F_o2i_ECPublicKey 158
396 #define EC_F_BN_to_felem 159
397 #define EC_F_ec_GFp_nistp256_group_set_curve 160
398 #define EC_F_ec_GFp_nistp256_point_get_affine_coordinates 161
399 #define EC_F_ec_GFp_nistp256_points_mul 162
400 #define EC_F_ec_group_copy 163
401 #define EC_F_nistp256_pre_comp_new 164
402 #define EC_F_EC_KEY_new_by_curve_name 165
403 #define EC_F_EC_GROUP_new_curve_GFp 166
404 #define EC_R_BUFFER_TOO_SMALL 100
405 #define EC_R_COORDINATES_OUT_OF_RANGE 101
406 #define EC_R_D2I_ECPKPARAMETERS_FAILURE 102
407 #define EC_R_EC_GROUP_NEW_BY_NAME_FAILURE 103
408 #define EC_R_GROUP2PKPARAMETERS_FAILURE 104
409 #define EC_R_I2D_ECPKPARAMETERS_FAILURE 105
410 #define EC_R_INCOMPATIBLE_OBJECTS 106
411 #define EC_R_INVALID_COMPRESSED_POINT 107
412 #define EC_R_INVALID_COMPRESSION_BIT 108
413 #define EC_R_INVALID_ENCODING 109
414 #define EC_R_INVALID_FIELD 110
415 #define EC_R_INVALID_FORM 111
416 #define EC_R_INVALID_GROUP_ORDER 112
417 #define EC_R_INVALID_PRIVATE_KEY 113
418 #define EC_R_MISSING_PARAMETERS 114
419 #define EC_R_MISSING_PRIVATE_KEY 115
420 #define EC_R_NON_NAMED_CURVE 116
421 #define EC_R_NOT_INITIALIZED 117
422 #define EC_R_PKPARAMETERS2GROUP_FAILURE 118
423 #define EC_R_POINT_AT_INFINITY 119
424 #define EC_R_POINT_IS_NOT_ON_CURVE 120
425 #define EC_R_SLOT_FULL 121
426 #define EC_R_UNDEFINED_GENERATOR 122
427 #define EC_R_UNKNOWN_GROUP 123
428 #define EC_R_UNKNOWN_ORDER 124
429 #define EC_R_WRONG_ORDER 125
430 #define EC_R_BIGNUM_OUT_OF_RANGE 126
431 #define EC_R_WRONG_CURVE_PARAMETERS 127
432 
433 #endif  /* OPENSSL_HEADER_EC_H */
434