1 /*
2 * Copyright 2001-2021 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
4 *
5 * Licensed under the Apache License 2.0 (the "License"). You may not use
6 * this file except in compliance with the License. You can obtain a copy
7 * in the file LICENSE in the source distribution or at
8 * https://www.openssl.org/source/license.html
9 */
10
11 #include <stdlib.h>
12
13 #include <openssl/obj_mac.h>
14 #include <openssl/ec.h>
15 #include <openssl/bn.h>
16 #include "internal/refcount.h"
17 #include "crypto/ec.h"
18
19 #if defined(__SUNPRO_C)
20 # if __SUNPRO_C >= 0x520
21 # pragma error_messages (off,E_ARRAY_OF_INCOMPLETE_NONAME,E_ARRAY_OF_INCOMPLETE)
22 # endif
23 #endif
24
25 /* Use default functions for poin2oct, oct2point and compressed coordinates */
26 #define EC_FLAGS_DEFAULT_OCT 0x1
27
28 /* Use custom formats for EC_GROUP, EC_POINT and EC_KEY */
29 #define EC_FLAGS_CUSTOM_CURVE 0x2
30
31 /* Curve does not support signing operations */
32 #define EC_FLAGS_NO_SIGN 0x4
33
34 #ifdef OPENSSL_NO_DEPRECATED_3_0
35 typedef struct ec_method_st EC_METHOD;
36 #endif
37
38 /*
39 * Structure details are not part of the exported interface, so all this may
40 * change in future versions.
41 */
42
43 struct ec_method_st {
44 /* Various method flags */
45 int flags;
46 /* used by EC_METHOD_get_field_type: */
47 int field_type; /* a NID */
48 /*
49 * used by EC_GROUP_new, EC_GROUP_free, EC_GROUP_clear_free,
50 * EC_GROUP_copy:
51 */
52 int (*group_init) (EC_GROUP *);
53 void (*group_finish) (EC_GROUP *);
54 void (*group_clear_finish) (EC_GROUP *);
55 int (*group_copy) (EC_GROUP *, const EC_GROUP *);
56 /* used by EC_GROUP_set_curve, EC_GROUP_get_curve: */
57 int (*group_set_curve) (EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
58 const BIGNUM *b, BN_CTX *);
59 int (*group_get_curve) (const EC_GROUP *, BIGNUM *p, BIGNUM *a, BIGNUM *b,
60 BN_CTX *);
61 /* used by EC_GROUP_get_degree: */
62 int (*group_get_degree) (const EC_GROUP *);
63 int (*group_order_bits) (const EC_GROUP *);
64 /* used by EC_GROUP_check: */
65 int (*group_check_discriminant) (const EC_GROUP *, BN_CTX *);
66 /*
67 * used by EC_POINT_new, EC_POINT_free, EC_POINT_clear_free,
68 * EC_POINT_copy:
69 */
70 int (*point_init) (EC_POINT *);
71 void (*point_finish) (EC_POINT *);
72 void (*point_clear_finish) (EC_POINT *);
73 int (*point_copy) (EC_POINT *, const EC_POINT *);
74 /*-
75 * used by EC_POINT_set_to_infinity,
76 * EC_POINT_set_Jprojective_coordinates_GFp,
77 * EC_POINT_get_Jprojective_coordinates_GFp,
78 * EC_POINT_set_affine_coordinates,
79 * EC_POINT_get_affine_coordinates,
80 * EC_POINT_set_compressed_coordinates:
81 */
82 int (*point_set_to_infinity) (const EC_GROUP *, EC_POINT *);
83 int (*point_set_affine_coordinates) (const EC_GROUP *, EC_POINT *,
84 const BIGNUM *x, const BIGNUM *y,
85 BN_CTX *);
86 int (*point_get_affine_coordinates) (const EC_GROUP *, const EC_POINT *,
87 BIGNUM *x, BIGNUM *y, BN_CTX *);
88 int (*point_set_compressed_coordinates) (const EC_GROUP *, EC_POINT *,
89 const BIGNUM *x, int y_bit,
90 BN_CTX *);
91 /* used by EC_POINT_point2oct, EC_POINT_oct2point: */
92 size_t (*point2oct) (const EC_GROUP *, const EC_POINT *,
93 point_conversion_form_t form, unsigned char *buf,
94 size_t len, BN_CTX *);
95 int (*oct2point) (const EC_GROUP *, EC_POINT *, const unsigned char *buf,
96 size_t len, BN_CTX *);
97 /* used by EC_POINT_add, EC_POINT_dbl, ECP_POINT_invert: */
98 int (*add) (const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
99 const EC_POINT *b, BN_CTX *);
100 int (*dbl) (const EC_GROUP *, EC_POINT *r, const EC_POINT *a, BN_CTX *);
101 int (*invert) (const EC_GROUP *, EC_POINT *, BN_CTX *);
102 /*
103 * used by EC_POINT_is_at_infinity, EC_POINT_is_on_curve, EC_POINT_cmp:
104 */
105 int (*is_at_infinity) (const EC_GROUP *, const EC_POINT *);
106 int (*is_on_curve) (const EC_GROUP *, const EC_POINT *, BN_CTX *);
107 int (*point_cmp) (const EC_GROUP *, const EC_POINT *a, const EC_POINT *b,
108 BN_CTX *);
109 /* used by EC_POINT_make_affine, EC_POINTs_make_affine: */
110 int (*make_affine) (const EC_GROUP *, EC_POINT *, BN_CTX *);
111 int (*points_make_affine) (const EC_GROUP *, size_t num, EC_POINT *[],
112 BN_CTX *);
113 /*
114 * used by EC_POINTs_mul, EC_POINT_mul, EC_POINT_precompute_mult,
115 * EC_POINT_have_precompute_mult (default implementations are used if the
116 * 'mul' pointer is 0):
117 */
118 /*-
119 * mul() calculates the value
120 *
121 * r := generator * scalar
122 * + points[0] * scalars[0]
123 * + ...
124 * + points[num-1] * scalars[num-1].
125 *
126 * For a fixed point multiplication (scalar != NULL, num == 0)
127 * or a variable point multiplication (scalar == NULL, num == 1),
128 * mul() must use a constant time algorithm: in both cases callers
129 * should provide an input scalar (either scalar or scalars[0])
130 * in the range [0, ec_group_order); for robustness, implementers
131 * should handle the case when the scalar has not been reduced, but
132 * may treat it as an unusual input, without any constant-timeness
133 * guarantee.
134 */
135 int (*mul) (const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
136 size_t num, const EC_POINT *points[], const BIGNUM *scalars[],
137 BN_CTX *);
138 int (*precompute_mult) (EC_GROUP *group, BN_CTX *);
139 int (*have_precompute_mult) (const EC_GROUP *group);
140 /* internal functions */
141 /*
142 * 'field_mul', 'field_sqr', and 'field_div' can be used by 'add' and
143 * 'dbl' so that the same implementations of point operations can be used
144 * with different optimized implementations of expensive field
145 * operations:
146 */
147 int (*field_mul) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
148 const BIGNUM *b, BN_CTX *);
149 int (*field_sqr) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a, BN_CTX *);
150 int (*field_div) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
151 const BIGNUM *b, BN_CTX *);
152 /*-
153 * 'field_inv' computes the multiplicative inverse of a in the field,
154 * storing the result in r.
155 *
156 * If 'a' is zero (or equivalent), you'll get an EC_R_CANNOT_INVERT error.
157 */
158 int (*field_inv) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a, BN_CTX *);
159 /* e.g. to Montgomery */
160 int (*field_encode) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
161 BN_CTX *);
162 /* e.g. from Montgomery */
163 int (*field_decode) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
164 BN_CTX *);
165 int (*field_set_to_one) (const EC_GROUP *, BIGNUM *r, BN_CTX *);
166 /* private key operations */
167 size_t (*priv2oct)(const EC_KEY *eckey, unsigned char *buf, size_t len);
168 int (*oct2priv)(EC_KEY *eckey, const unsigned char *buf, size_t len);
169 int (*set_private)(EC_KEY *eckey, const BIGNUM *priv_key);
170 int (*keygen)(EC_KEY *eckey);
171 int (*keycheck)(const EC_KEY *eckey);
172 int (*keygenpub)(EC_KEY *eckey);
173 int (*keycopy)(EC_KEY *dst, const EC_KEY *src);
174 void (*keyfinish)(EC_KEY *eckey);
175 /* custom ECDH operation */
176 int (*ecdh_compute_key)(unsigned char **pout, size_t *poutlen,
177 const EC_POINT *pub_key, const EC_KEY *ecdh);
178 /* custom ECDSA */
179 int (*ecdsa_sign_setup)(EC_KEY *eckey, BN_CTX *ctx, BIGNUM **kinvp,
180 BIGNUM **rp);
181 ECDSA_SIG *(*ecdsa_sign_sig)(const unsigned char *dgst, int dgstlen,
182 const BIGNUM *kinv, const BIGNUM *r,
183 EC_KEY *eckey);
184 int (*ecdsa_verify_sig)(const unsigned char *dgst, int dgstlen,
185 const ECDSA_SIG *sig, EC_KEY *eckey);
186 /* Inverse modulo order */
187 int (*field_inverse_mod_ord)(const EC_GROUP *, BIGNUM *r,
188 const BIGNUM *x, BN_CTX *);
189 int (*blind_coordinates)(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx);
190 int (*ladder_pre)(const EC_GROUP *group,
191 EC_POINT *r, EC_POINT *s,
192 EC_POINT *p, BN_CTX *ctx);
193 int (*ladder_step)(const EC_GROUP *group,
194 EC_POINT *r, EC_POINT *s,
195 EC_POINT *p, BN_CTX *ctx);
196 int (*ladder_post)(const EC_GROUP *group,
197 EC_POINT *r, EC_POINT *s,
198 EC_POINT *p, BN_CTX *ctx);
199 };
200
201 /*
202 * Types and functions to manipulate pre-computed values.
203 */
204 typedef struct nistp224_pre_comp_st NISTP224_PRE_COMP;
205 typedef struct nistp256_pre_comp_st NISTP256_PRE_COMP;
206 typedef struct nistp521_pre_comp_st NISTP521_PRE_COMP;
207 typedef struct nistz256_pre_comp_st NISTZ256_PRE_COMP;
208 typedef struct ec_pre_comp_st EC_PRE_COMP;
209
210 struct ec_group_st {
211 const EC_METHOD *meth;
212 EC_POINT *generator; /* optional */
213 BIGNUM *order, *cofactor;
214 int curve_name; /* optional NID for named curve */
215 int asn1_flag; /* flag to control the asn1 encoding */
216 int decoded_from_explicit_params; /* set if decoded from explicit
217 * curve parameters encoding */
218 point_conversion_form_t asn1_form;
219 unsigned char *seed; /* optional seed for parameters (appears in
220 * ASN1) */
221 size_t seed_len;
222 /*
223 * The following members are handled by the method functions, even if
224 * they appear generic
225 */
226 /*
227 * Field specification. For curves over GF(p), this is the modulus; for
228 * curves over GF(2^m), this is the irreducible polynomial defining the
229 * field.
230 */
231 BIGNUM *field;
232 /*
233 * Field specification for curves over GF(2^m). The irreducible f(t) is
234 * then of the form: t^poly[0] + t^poly[1] + ... + t^poly[k] where m =
235 * poly[0] > poly[1] > ... > poly[k] = 0. The array is terminated with
236 * poly[k+1]=-1. All elliptic curve irreducibles have at most 5 non-zero
237 * terms.
238 */
239 int poly[6];
240 /*
241 * Curve coefficients. (Here the assumption is that BIGNUMs can be used
242 * or abused for all kinds of fields, not just GF(p).) For characteristic
243 * > 3, the curve is defined by a Weierstrass equation of the form y^2 =
244 * x^3 + a*x + b. For characteristic 2, the curve is defined by an
245 * equation of the form y^2 + x*y = x^3 + a*x^2 + b.
246 */
247 BIGNUM *a, *b;
248 /* enable optimized point arithmetics for special case */
249 int a_is_minus3;
250 /* method-specific (e.g., Montgomery structure) */
251 void *field_data1;
252 /* method-specific */
253 void *field_data2;
254 /* method-specific */
255 int (*field_mod_func) (BIGNUM *, const BIGNUM *, const BIGNUM *,
256 BN_CTX *);
257 /* data for ECDSA inverse */
258 BN_MONT_CTX *mont_data;
259
260 /*
261 * Precomputed values for speed. The PCT_xxx names match the
262 * pre_comp.xxx union names; see the SETPRECOMP and HAVEPRECOMP
263 * macros, below.
264 */
265 enum {
266 PCT_none,
267 PCT_nistp224, PCT_nistp256, PCT_nistp521, PCT_nistz256,
268 PCT_ec
269 } pre_comp_type;
270 union {
271 NISTP224_PRE_COMP *nistp224;
272 NISTP256_PRE_COMP *nistp256;
273 NISTP521_PRE_COMP *nistp521;
274 NISTZ256_PRE_COMP *nistz256;
275 EC_PRE_COMP *ec;
276 } pre_comp;
277
278 OSSL_LIB_CTX *libctx;
279 char *propq;
280 };
281
282 #define SETPRECOMP(g, type, pre) \
283 g->pre_comp_type = PCT_##type, g->pre_comp.type = pre
284 #define HAVEPRECOMP(g, type) \
285 g->pre_comp_type == PCT_##type && g->pre_comp.type != NULL
286
287 struct ec_key_st {
288 const EC_KEY_METHOD *meth;
289 ENGINE *engine;
290 int version;
291 EC_GROUP *group;
292 EC_POINT *pub_key;
293 BIGNUM *priv_key;
294 unsigned int enc_flag;
295 point_conversion_form_t conv_form;
296 CRYPTO_REF_COUNT references;
297 int flags;
298 #ifndef FIPS_MODULE
299 CRYPTO_EX_DATA ex_data;
300 #endif
301 CRYPTO_RWLOCK *lock;
302 OSSL_LIB_CTX *libctx;
303 char *propq;
304
305 /* Provider data */
306 size_t dirty_cnt; /* If any key material changes, increment this */
307 };
308
309 struct ec_point_st {
310 const EC_METHOD *meth;
311 /* NID for the curve if known */
312 int curve_name;
313 /*
314 * All members except 'meth' are handled by the method functions, even if
315 * they appear generic
316 */
317 BIGNUM *X;
318 BIGNUM *Y;
319 BIGNUM *Z; /* Jacobian projective coordinates: * (X, Y,
320 * Z) represents (X/Z^2, Y/Z^3) if Z != 0 */
321 int Z_is_one; /* enable optimized point arithmetics for
322 * special case */
323 };
324
ec_point_is_compat(const EC_POINT * point,const EC_GROUP * group)325 static ossl_inline int ec_point_is_compat(const EC_POINT *point,
326 const EC_GROUP *group)
327 {
328 return group->meth == point->meth
329 && (group->curve_name == 0
330 || point->curve_name == 0
331 || group->curve_name == point->curve_name);
332 }
333
334 NISTP224_PRE_COMP *EC_nistp224_pre_comp_dup(NISTP224_PRE_COMP *);
335 NISTP256_PRE_COMP *EC_nistp256_pre_comp_dup(NISTP256_PRE_COMP *);
336 NISTP521_PRE_COMP *EC_nistp521_pre_comp_dup(NISTP521_PRE_COMP *);
337 NISTZ256_PRE_COMP *EC_nistz256_pre_comp_dup(NISTZ256_PRE_COMP *);
338 NISTP256_PRE_COMP *EC_nistp256_pre_comp_dup(NISTP256_PRE_COMP *);
339 EC_PRE_COMP *EC_ec_pre_comp_dup(EC_PRE_COMP *);
340
341 void EC_pre_comp_free(EC_GROUP *group);
342 void EC_nistp224_pre_comp_free(NISTP224_PRE_COMP *);
343 void EC_nistp256_pre_comp_free(NISTP256_PRE_COMP *);
344 void EC_nistp521_pre_comp_free(NISTP521_PRE_COMP *);
345 void EC_nistz256_pre_comp_free(NISTZ256_PRE_COMP *);
346 void EC_ec_pre_comp_free(EC_PRE_COMP *);
347
348 /*
349 * method functions in ec_mult.c (ec_lib.c uses these as defaults if
350 * group->method->mul is 0)
351 */
352 int ossl_ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
353 size_t num, const EC_POINT *points[],
354 const BIGNUM *scalars[], BN_CTX *);
355 int ossl_ec_wNAF_precompute_mult(EC_GROUP *group, BN_CTX *);
356 int ossl_ec_wNAF_have_precompute_mult(const EC_GROUP *group);
357
358 /* method functions in ecp_smpl.c */
359 int ossl_ec_GFp_simple_group_init(EC_GROUP *);
360 void ossl_ec_GFp_simple_group_finish(EC_GROUP *);
361 void ossl_ec_GFp_simple_group_clear_finish(EC_GROUP *);
362 int ossl_ec_GFp_simple_group_copy(EC_GROUP *, const EC_GROUP *);
363 int ossl_ec_GFp_simple_group_set_curve(EC_GROUP *, const BIGNUM *p,
364 const BIGNUM *a, const BIGNUM *b,
365 BN_CTX *);
366 int ossl_ec_GFp_simple_group_get_curve(const EC_GROUP *, BIGNUM *p, BIGNUM *a,
367 BIGNUM *b, BN_CTX *);
368 int ossl_ec_GFp_simple_group_get_degree(const EC_GROUP *);
369 int ossl_ec_GFp_simple_group_check_discriminant(const EC_GROUP *, BN_CTX *);
370 int ossl_ec_GFp_simple_point_init(EC_POINT *);
371 void ossl_ec_GFp_simple_point_finish(EC_POINT *);
372 void ossl_ec_GFp_simple_point_clear_finish(EC_POINT *);
373 int ossl_ec_GFp_simple_point_copy(EC_POINT *, const EC_POINT *);
374 int ossl_ec_GFp_simple_point_set_to_infinity(const EC_GROUP *, EC_POINT *);
375 int ossl_ec_GFp_simple_set_Jprojective_coordinates_GFp(const EC_GROUP *,
376 EC_POINT *,
377 const BIGNUM *x,
378 const BIGNUM *y,
379 const BIGNUM *z,
380 BN_CTX *);
381 int ossl_ec_GFp_simple_get_Jprojective_coordinates_GFp(const EC_GROUP *,
382 const EC_POINT *,
383 BIGNUM *x,
384 BIGNUM *y, BIGNUM *z,
385 BN_CTX *);
386 int ossl_ec_GFp_simple_point_set_affine_coordinates(const EC_GROUP *, EC_POINT *,
387 const BIGNUM *x,
388 const BIGNUM *y, BN_CTX *);
389 int ossl_ec_GFp_simple_point_get_affine_coordinates(const EC_GROUP *,
390 const EC_POINT *, BIGNUM *x,
391 BIGNUM *y, BN_CTX *);
392 int ossl_ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *, EC_POINT *,
393 const BIGNUM *x, int y_bit,
394 BN_CTX *);
395 size_t ossl_ec_GFp_simple_point2oct(const EC_GROUP *, const EC_POINT *,
396 point_conversion_form_t form,
397 unsigned char *buf, size_t len, BN_CTX *);
398 int ossl_ec_GFp_simple_oct2point(const EC_GROUP *, EC_POINT *,
399 const unsigned char *buf, size_t len, BN_CTX *);
400 int ossl_ec_GFp_simple_add(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
401 const EC_POINT *b, BN_CTX *);
402 int ossl_ec_GFp_simple_dbl(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
403 BN_CTX *);
404 int ossl_ec_GFp_simple_invert(const EC_GROUP *, EC_POINT *, BN_CTX *);
405 int ossl_ec_GFp_simple_is_at_infinity(const EC_GROUP *, const EC_POINT *);
406 int ossl_ec_GFp_simple_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
407 int ossl_ec_GFp_simple_cmp(const EC_GROUP *, const EC_POINT *a,
408 const EC_POINT *b, BN_CTX *);
409 int ossl_ec_GFp_simple_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
410 int ossl_ec_GFp_simple_points_make_affine(const EC_GROUP *, size_t num,
411 EC_POINT *[], BN_CTX *);
412 int ossl_ec_GFp_simple_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
413 const BIGNUM *b, BN_CTX *);
414 int ossl_ec_GFp_simple_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
415 BN_CTX *);
416 int ossl_ec_GFp_simple_field_inv(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
417 BN_CTX *);
418 int ossl_ec_GFp_simple_blind_coordinates(const EC_GROUP *group, EC_POINT *p,
419 BN_CTX *ctx);
420 int ossl_ec_GFp_simple_ladder_pre(const EC_GROUP *group,
421 EC_POINT *r, EC_POINT *s,
422 EC_POINT *p, BN_CTX *ctx);
423 int ossl_ec_GFp_simple_ladder_step(const EC_GROUP *group,
424 EC_POINT *r, EC_POINT *s,
425 EC_POINT *p, BN_CTX *ctx);
426 int ossl_ec_GFp_simple_ladder_post(const EC_GROUP *group,
427 EC_POINT *r, EC_POINT *s,
428 EC_POINT *p, BN_CTX *ctx);
429
430 /* method functions in ecp_mont.c */
431 int ossl_ec_GFp_mont_group_init(EC_GROUP *);
432 int ossl_ec_GFp_mont_group_set_curve(EC_GROUP *, const BIGNUM *p,
433 const BIGNUM *a,
434 const BIGNUM *b, BN_CTX *);
435 void ossl_ec_GFp_mont_group_finish(EC_GROUP *);
436 void ossl_ec_GFp_mont_group_clear_finish(EC_GROUP *);
437 int ossl_ec_GFp_mont_group_copy(EC_GROUP *, const EC_GROUP *);
438 int ossl_ec_GFp_mont_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
439 const BIGNUM *b, BN_CTX *);
440 int ossl_ec_GFp_mont_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
441 BN_CTX *);
442 int ossl_ec_GFp_mont_field_inv(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
443 BN_CTX *);
444 int ossl_ec_GFp_mont_field_encode(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
445 BN_CTX *);
446 int ossl_ec_GFp_mont_field_decode(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
447 BN_CTX *);
448 int ossl_ec_GFp_mont_field_set_to_one(const EC_GROUP *, BIGNUM *r, BN_CTX *);
449
450 /* method functions in ecp_nist.c */
451 int ossl_ec_GFp_nist_group_copy(EC_GROUP *dest, const EC_GROUP *src);
452 int ossl_ec_GFp_nist_group_set_curve(EC_GROUP *, const BIGNUM *p,
453 const BIGNUM *a, const BIGNUM *b, BN_CTX *);
454 int ossl_ec_GFp_nist_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
455 const BIGNUM *b, BN_CTX *);
456 int ossl_ec_GFp_nist_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
457 BN_CTX *);
458
459 /* method functions in ec2_smpl.c */
460 int ossl_ec_GF2m_simple_group_init(EC_GROUP *);
461 void ossl_ec_GF2m_simple_group_finish(EC_GROUP *);
462 void ossl_ec_GF2m_simple_group_clear_finish(EC_GROUP *);
463 int ossl_ec_GF2m_simple_group_copy(EC_GROUP *, const EC_GROUP *);
464 int ossl_ec_GF2m_simple_group_set_curve(EC_GROUP *, const BIGNUM *p,
465 const BIGNUM *a, const BIGNUM *b,
466 BN_CTX *);
467 int ossl_ec_GF2m_simple_group_get_curve(const EC_GROUP *, BIGNUM *p, BIGNUM *a,
468 BIGNUM *b, BN_CTX *);
469 int ossl_ec_GF2m_simple_group_get_degree(const EC_GROUP *);
470 int ossl_ec_GF2m_simple_group_check_discriminant(const EC_GROUP *, BN_CTX *);
471 int ossl_ec_GF2m_simple_point_init(EC_POINT *);
472 void ossl_ec_GF2m_simple_point_finish(EC_POINT *);
473 void ossl_ec_GF2m_simple_point_clear_finish(EC_POINT *);
474 int ossl_ec_GF2m_simple_point_copy(EC_POINT *, const EC_POINT *);
475 int ossl_ec_GF2m_simple_point_set_to_infinity(const EC_GROUP *, EC_POINT *);
476 int ossl_ec_GF2m_simple_point_set_affine_coordinates(const EC_GROUP *,
477 EC_POINT *,
478 const BIGNUM *x,
479 const BIGNUM *y, BN_CTX *);
480 int ossl_ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *,
481 const EC_POINT *, BIGNUM *x,
482 BIGNUM *y, BN_CTX *);
483 int ossl_ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *, EC_POINT *,
484 const BIGNUM *x, int y_bit,
485 BN_CTX *);
486 size_t ossl_ec_GF2m_simple_point2oct(const EC_GROUP *, const EC_POINT *,
487 point_conversion_form_t form,
488 unsigned char *buf, size_t len, BN_CTX *);
489 int ossl_ec_GF2m_simple_oct2point(const EC_GROUP *, EC_POINT *,
490 const unsigned char *buf, size_t len, BN_CTX *);
491 int ossl_ec_GF2m_simple_add(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
492 const EC_POINT *b, BN_CTX *);
493 int ossl_ec_GF2m_simple_dbl(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
494 BN_CTX *);
495 int ossl_ec_GF2m_simple_invert(const EC_GROUP *, EC_POINT *, BN_CTX *);
496 int ossl_ec_GF2m_simple_is_at_infinity(const EC_GROUP *, const EC_POINT *);
497 int ossl_ec_GF2m_simple_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
498 int ossl_ec_GF2m_simple_cmp(const EC_GROUP *, const EC_POINT *a,
499 const EC_POINT *b, BN_CTX *);
500 int ossl_ec_GF2m_simple_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
501 int ossl_ec_GF2m_simple_points_make_affine(const EC_GROUP *, size_t num,
502 EC_POINT *[], BN_CTX *);
503 int ossl_ec_GF2m_simple_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
504 const BIGNUM *b, BN_CTX *);
505 int ossl_ec_GF2m_simple_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
506 BN_CTX *);
507 int ossl_ec_GF2m_simple_field_div(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
508 const BIGNUM *b, BN_CTX *);
509
510 #ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
511 # ifdef B_ENDIAN
512 # error "Can not enable ec_nistp_64_gcc_128 on big-endian systems"
513 # endif
514
515 /* method functions in ecp_nistp224.c */
516 int ossl_ec_GFp_nistp224_group_init(EC_GROUP *group);
517 int ossl_ec_GFp_nistp224_group_set_curve(EC_GROUP *group, const BIGNUM *p,
518 const BIGNUM *a, const BIGNUM *n,
519 BN_CTX *);
520 int ossl_ec_GFp_nistp224_point_get_affine_coordinates(const EC_GROUP *group,
521 const EC_POINT *point,
522 BIGNUM *x, BIGNUM *y,
523 BN_CTX *ctx);
524 int ossl_ec_GFp_nistp224_mul(const EC_GROUP *group, EC_POINT *r,
525 const BIGNUM *scalar, size_t num,
526 const EC_POINT *points[], const BIGNUM *scalars[],
527 BN_CTX *);
528 int ossl_ec_GFp_nistp224_points_mul(const EC_GROUP *group, EC_POINT *r,
529 const BIGNUM *scalar, size_t num,
530 const EC_POINT *points[],
531 const BIGNUM *scalars[], BN_CTX *ctx);
532 int ossl_ec_GFp_nistp224_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
533 int ossl_ec_GFp_nistp224_have_precompute_mult(const EC_GROUP *group);
534
535 /* method functions in ecp_nistp256.c */
536 int ossl_ec_GFp_nistp256_group_init(EC_GROUP *group);
537 int ossl_ec_GFp_nistp256_group_set_curve(EC_GROUP *group, const BIGNUM *p,
538 const BIGNUM *a, const BIGNUM *n,
539 BN_CTX *);
540 int ossl_ec_GFp_nistp256_point_get_affine_coordinates(const EC_GROUP *group,
541 const EC_POINT *point,
542 BIGNUM *x, BIGNUM *y,
543 BN_CTX *ctx);
544 int ossl_ec_GFp_nistp256_mul(const EC_GROUP *group, EC_POINT *r,
545 const BIGNUM *scalar, size_t num,
546 const EC_POINT *points[], const BIGNUM *scalars[],
547 BN_CTX *);
548 int ossl_ec_GFp_nistp256_points_mul(const EC_GROUP *group, EC_POINT *r,
549 const BIGNUM *scalar, size_t num,
550 const EC_POINT *points[],
551 const BIGNUM *scalars[], BN_CTX *ctx);
552 int ossl_ec_GFp_nistp256_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
553 int ossl_ec_GFp_nistp256_have_precompute_mult(const EC_GROUP *group);
554
555 /* method functions in ecp_nistp521.c */
556 int ossl_ec_GFp_nistp521_group_init(EC_GROUP *group);
557 int ossl_ec_GFp_nistp521_group_set_curve(EC_GROUP *group, const BIGNUM *p,
558 const BIGNUM *a, const BIGNUM *n,
559 BN_CTX *);
560 int ossl_ec_GFp_nistp521_point_get_affine_coordinates(const EC_GROUP *group,
561 const EC_POINT *point,
562 BIGNUM *x, BIGNUM *y,
563 BN_CTX *ctx);
564 int ossl_ec_GFp_nistp521_mul(const EC_GROUP *group, EC_POINT *r,
565 const BIGNUM *scalar, size_t num,
566 const EC_POINT *points[], const BIGNUM *scalars[],
567 BN_CTX *);
568 int ossl_ec_GFp_nistp521_points_mul(const EC_GROUP *group, EC_POINT *r,
569 const BIGNUM *scalar, size_t num,
570 const EC_POINT *points[],
571 const BIGNUM *scalars[], BN_CTX *ctx);
572 int ossl_ec_GFp_nistp521_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
573 int ossl_ec_GFp_nistp521_have_precompute_mult(const EC_GROUP *group);
574
575 /* utility functions in ecp_nistputil.c */
576 void ossl_ec_GFp_nistp_points_make_affine_internal(size_t num, void *point_array,
577 size_t felem_size,
578 void *tmp_felems,
579 void (*felem_one) (void *out),
580 int (*felem_is_zero)
581 (const void *in),
582 void (*felem_assign)
583 (void *out, const void *in),
584 void (*felem_square)
585 (void *out, const void *in),
586 void (*felem_mul)
587 (void *out,
588 const void *in1,
589 const void *in2),
590 void (*felem_inv)
591 (void *out, const void *in),
592 void (*felem_contract)
593 (void *out, const void *in));
594 void ossl_ec_GFp_nistp_recode_scalar_bits(unsigned char *sign,
595 unsigned char *digit,
596 unsigned char in);
597 #endif
598 int ossl_ec_group_simple_order_bits(const EC_GROUP *group);
599
600 /**
601 * Creates a new EC_GROUP object
602 * \param libctx The associated library context or NULL for the default
603 * library context
604 * \param propq Any property query string
605 * \param meth EC_METHOD to use
606 * \return newly created EC_GROUP object or NULL in case of an error.
607 */
608 EC_GROUP *ossl_ec_group_new_ex(OSSL_LIB_CTX *libctx, const char *propq,
609 const EC_METHOD *meth);
610
611 #ifdef ECP_NISTZ256_ASM
612 /** Returns GFp methods using montgomery multiplication, with x86-64 optimized
613 * P256. See http://eprint.iacr.org/2013/816.
614 * \return EC_METHOD object
615 */
616 const EC_METHOD *EC_GFp_nistz256_method(void);
617 #endif
618 #ifdef S390X_EC_ASM
619 const EC_METHOD *EC_GFp_s390x_nistp256_method(void);
620 const EC_METHOD *EC_GFp_s390x_nistp384_method(void);
621 const EC_METHOD *EC_GFp_s390x_nistp521_method(void);
622 #endif
623
624 size_t ossl_ec_key_simple_priv2oct(const EC_KEY *eckey,
625 unsigned char *buf, size_t len);
626 int ossl_ec_key_simple_oct2priv(EC_KEY *eckey, const unsigned char *buf,
627 size_t len);
628 int ossl_ec_key_simple_generate_key(EC_KEY *eckey);
629 int ossl_ec_key_simple_generate_public_key(EC_KEY *eckey);
630 int ossl_ec_key_simple_check_key(const EC_KEY *eckey);
631
632 int ossl_ec_curve_nid_from_params(const EC_GROUP *group, BN_CTX *ctx);
633
634 /* EC_METHOD definitions */
635
636 struct ec_key_method_st {
637 const char *name;
638 int32_t flags;
639 int (*init)(EC_KEY *key);
640 void (*finish)(EC_KEY *key);
641 int (*copy)(EC_KEY *dest, const EC_KEY *src);
642 int (*set_group)(EC_KEY *key, const EC_GROUP *grp);
643 int (*set_private)(EC_KEY *key, const BIGNUM *priv_key);
644 int (*set_public)(EC_KEY *key, const EC_POINT *pub_key);
645 int (*keygen)(EC_KEY *key);
646 int (*compute_key)(unsigned char **pout, size_t *poutlen,
647 const EC_POINT *pub_key, const EC_KEY *ecdh);
648 int (*sign)(int type, const unsigned char *dgst, int dlen, unsigned char
649 *sig, unsigned int *siglen, const BIGNUM *kinv,
650 const BIGNUM *r, EC_KEY *eckey);
651 int (*sign_setup)(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
652 BIGNUM **rp);
653 ECDSA_SIG *(*sign_sig)(const unsigned char *dgst, int dgst_len,
654 const BIGNUM *in_kinv, const BIGNUM *in_r,
655 EC_KEY *eckey);
656
657 int (*verify)(int type, const unsigned char *dgst, int dgst_len,
658 const unsigned char *sigbuf, int sig_len, EC_KEY *eckey);
659 int (*verify_sig)(const unsigned char *dgst, int dgst_len,
660 const ECDSA_SIG *sig, EC_KEY *eckey);
661 };
662
663 #define EC_KEY_METHOD_DYNAMIC 1
664
665 EC_KEY *ossl_ec_key_new_method_int(OSSL_LIB_CTX *libctx, const char *propq,
666 ENGINE *engine);
667
668 int ossl_ec_key_gen(EC_KEY *eckey);
669 int ossl_ecdh_compute_key(unsigned char **pout, size_t *poutlen,
670 const EC_POINT *pub_key, const EC_KEY *ecdh);
671 int ossl_ecdh_simple_compute_key(unsigned char **pout, size_t *poutlen,
672 const EC_POINT *pub_key, const EC_KEY *ecdh);
673
674 struct ECDSA_SIG_st {
675 BIGNUM *r;
676 BIGNUM *s;
677 };
678
679 int ossl_ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
680 BIGNUM **rp);
681 int ossl_ecdsa_sign(int type, const unsigned char *dgst, int dlen,
682 unsigned char *sig, unsigned int *siglen,
683 const BIGNUM *kinv, const BIGNUM *r, EC_KEY *eckey);
684 ECDSA_SIG *ossl_ecdsa_sign_sig(const unsigned char *dgst, int dgst_len,
685 const BIGNUM *in_kinv, const BIGNUM *in_r,
686 EC_KEY *eckey);
687 int ossl_ecdsa_verify(int type, const unsigned char *dgst, int dgst_len,
688 const unsigned char *sigbuf, int sig_len, EC_KEY *eckey);
689 int ossl_ecdsa_verify_sig(const unsigned char *dgst, int dgst_len,
690 const ECDSA_SIG *sig, EC_KEY *eckey);
691 int ossl_ecdsa_simple_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
692 BIGNUM **rp);
693 ECDSA_SIG *ossl_ecdsa_simple_sign_sig(const unsigned char *dgst, int dgst_len,
694 const BIGNUM *in_kinv, const BIGNUM *in_r,
695 EC_KEY *eckey);
696 int ossl_ecdsa_simple_verify_sig(const unsigned char *dgst, int dgst_len,
697 const ECDSA_SIG *sig, EC_KEY *eckey);
698
699
700 /*-
701 * This functions computes a single point multiplication over the EC group,
702 * using, at a high level, a Montgomery ladder with conditional swaps, with
703 * various timing attack defenses.
704 *
705 * It performs either a fixed point multiplication
706 * (scalar * generator)
707 * when point is NULL, or a variable point multiplication
708 * (scalar * point)
709 * when point is not NULL.
710 *
711 * `scalar` cannot be NULL and should be in the range [0,n) otherwise all
712 * constant time bets are off (where n is the cardinality of the EC group).
713 *
714 * This function expects `group->order` and `group->cardinality` to be well
715 * defined and non-zero: it fails with an error code otherwise.
716 *
717 * NB: This says nothing about the constant-timeness of the ladder step
718 * implementation (i.e., the default implementation is based on EC_POINT_add and
719 * EC_POINT_dbl, which of course are not constant time themselves) or the
720 * underlying multiprecision arithmetic.
721 *
722 * The product is stored in `r`.
723 *
724 * This is an internal function: callers are in charge of ensuring that the
725 * input parameters `group`, `r`, `scalar` and `ctx` are not NULL.
726 *
727 * Returns 1 on success, 0 otherwise.
728 */
729 int ossl_ec_scalar_mul_ladder(const EC_GROUP *group, EC_POINT *r,
730 const BIGNUM *scalar, const EC_POINT *point,
731 BN_CTX *ctx);
732
733 int ossl_ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p,
734 BN_CTX *ctx);
735
ec_point_ladder_pre(const EC_GROUP * group,EC_POINT * r,EC_POINT * s,EC_POINT * p,BN_CTX * ctx)736 static ossl_inline int ec_point_ladder_pre(const EC_GROUP *group,
737 EC_POINT *r, EC_POINT *s,
738 EC_POINT *p, BN_CTX *ctx)
739 {
740 if (group->meth->ladder_pre != NULL)
741 return group->meth->ladder_pre(group, r, s, p, ctx);
742
743 if (!EC_POINT_copy(s, p)
744 || !EC_POINT_dbl(group, r, s, ctx))
745 return 0;
746
747 return 1;
748 }
749
ec_point_ladder_step(const EC_GROUP * group,EC_POINT * r,EC_POINT * s,EC_POINT * p,BN_CTX * ctx)750 static ossl_inline int ec_point_ladder_step(const EC_GROUP *group,
751 EC_POINT *r, EC_POINT *s,
752 EC_POINT *p, BN_CTX *ctx)
753 {
754 if (group->meth->ladder_step != NULL)
755 return group->meth->ladder_step(group, r, s, p, ctx);
756
757 if (!EC_POINT_add(group, s, r, s, ctx)
758 || !EC_POINT_dbl(group, r, r, ctx))
759 return 0;
760
761 return 1;
762
763 }
764
ec_point_ladder_post(const EC_GROUP * group,EC_POINT * r,EC_POINT * s,EC_POINT * p,BN_CTX * ctx)765 static ossl_inline int ec_point_ladder_post(const EC_GROUP *group,
766 EC_POINT *r, EC_POINT *s,
767 EC_POINT *p, BN_CTX *ctx)
768 {
769 if (group->meth->ladder_post != NULL)
770 return group->meth->ladder_post(group, r, s, p, ctx);
771
772 return 1;
773 }
774