1/*
2 * Copyright 2001-2019 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
4 *
5 * Licensed under the OpenSSL license (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/*
35 * Structure details are not part of the exported interface, so all this may
36 * change in future versions.
37 */
38
39struct ec_method_st {
40    /* Various method flags */
41    int flags;
42    /* used by EC_METHOD_get_field_type: */
43    int field_type;             /* a NID */
44    /*
45     * used by EC_GROUP_new, EC_GROUP_free, EC_GROUP_clear_free,
46     * EC_GROUP_copy:
47     */
48    int (*group_init) (EC_GROUP *);
49    void (*group_finish) (EC_GROUP *);
50    void (*group_clear_finish) (EC_GROUP *);
51    int (*group_copy) (EC_GROUP *, const EC_GROUP *);
52    /* used by EC_GROUP_set_curve, EC_GROUP_get_curve: */
53    int (*group_set_curve) (EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
54                            const BIGNUM *b, BN_CTX *);
55    int (*group_get_curve) (const EC_GROUP *, BIGNUM *p, BIGNUM *a, BIGNUM *b,
56                            BN_CTX *);
57    /* used by EC_GROUP_get_degree: */
58    int (*group_get_degree) (const EC_GROUP *);
59    int (*group_order_bits) (const EC_GROUP *);
60    /* used by EC_GROUP_check: */
61    int (*group_check_discriminant) (const EC_GROUP *, BN_CTX *);
62    /*
63     * used by EC_POINT_new, EC_POINT_free, EC_POINT_clear_free,
64     * EC_POINT_copy:
65     */
66    int (*point_init) (EC_POINT *);
67    void (*point_finish) (EC_POINT *);
68    void (*point_clear_finish) (EC_POINT *);
69    int (*point_copy) (EC_POINT *, const EC_POINT *);
70    /*-
71     * used by EC_POINT_set_to_infinity,
72     * EC_POINT_set_Jprojective_coordinates_GFp,
73     * EC_POINT_get_Jprojective_coordinates_GFp,
74     * EC_POINT_set_affine_coordinates,
75     * EC_POINT_get_affine_coordinates,
76     * EC_POINT_set_compressed_coordinates:
77     */
78    int (*point_set_to_infinity) (const EC_GROUP *, EC_POINT *);
79    int (*point_set_Jprojective_coordinates_GFp) (const EC_GROUP *,
80                                                  EC_POINT *, const BIGNUM *x,
81                                                  const BIGNUM *y,
82                                                  const BIGNUM *z, BN_CTX *);
83    int (*point_get_Jprojective_coordinates_GFp) (const EC_GROUP *,
84                                                  const EC_POINT *, BIGNUM *x,
85                                                  BIGNUM *y, BIGNUM *z,
86                                                  BN_CTX *);
87    int (*point_set_affine_coordinates) (const EC_GROUP *, EC_POINT *,
88                                         const BIGNUM *x, const BIGNUM *y,
89                                         BN_CTX *);
90    int (*point_get_affine_coordinates) (const EC_GROUP *, const EC_POINT *,
91                                         BIGNUM *x, BIGNUM *y, BN_CTX *);
92    int (*point_set_compressed_coordinates) (const EC_GROUP *, EC_POINT *,
93                                             const BIGNUM *x, int y_bit,
94                                             BN_CTX *);
95    /* used by EC_POINT_point2oct, EC_POINT_oct2point: */
96    size_t (*point2oct) (const EC_GROUP *, const EC_POINT *,
97                         point_conversion_form_t form, unsigned char *buf,
98                         size_t len, BN_CTX *);
99    int (*oct2point) (const EC_GROUP *, EC_POINT *, const unsigned char *buf,
100                      size_t len, BN_CTX *);
101    /* used by EC_POINT_add, EC_POINT_dbl, ECP_POINT_invert: */
102    int (*add) (const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
103                const EC_POINT *b, BN_CTX *);
104    int (*dbl) (const EC_GROUP *, EC_POINT *r, const EC_POINT *a, BN_CTX *);
105    int (*invert) (const EC_GROUP *, EC_POINT *, BN_CTX *);
106    /*
107     * used by EC_POINT_is_at_infinity, EC_POINT_is_on_curve, EC_POINT_cmp:
108     */
109    int (*is_at_infinity) (const EC_GROUP *, const EC_POINT *);
110    int (*is_on_curve) (const EC_GROUP *, const EC_POINT *, BN_CTX *);
111    int (*point_cmp) (const EC_GROUP *, const EC_POINT *a, const EC_POINT *b,
112                      BN_CTX *);
113    /* used by EC_POINT_make_affine, EC_POINTs_make_affine: */
114    int (*make_affine) (const EC_GROUP *, EC_POINT *, BN_CTX *);
115    int (*points_make_affine) (const EC_GROUP *, size_t num, EC_POINT *[],
116                               BN_CTX *);
117    /*
118     * used by EC_POINTs_mul, EC_POINT_mul, EC_POINT_precompute_mult,
119     * EC_POINT_have_precompute_mult (default implementations are used if the
120     * 'mul' pointer is 0):
121     */
122    /*-
123     * mul() calculates the value
124     *
125     *   r := generator * scalar
126     *        + points[0] * scalars[0]
127     *        + ...
128     *        + points[num-1] * scalars[num-1].
129     *
130     * For a fixed point multiplication (scalar != NULL, num == 0)
131     * or a variable point multiplication (scalar == NULL, num == 1),
132     * mul() must use a constant time algorithm: in both cases callers
133     * should provide an input scalar (either scalar or scalars[0])
134     * in the range [0, ec_group_order); for robustness, implementers
135     * should handle the case when the scalar has not been reduced, but
136     * may treat it as an unusual input, without any constant-timeness
137     * guarantee.
138     */
139    int (*mul) (const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
140                size_t num, const EC_POINT *points[], const BIGNUM *scalars[],
141                BN_CTX *);
142    int (*precompute_mult) (EC_GROUP *group, BN_CTX *);
143    int (*have_precompute_mult) (const EC_GROUP *group);
144    /* internal functions */
145    /*
146     * 'field_mul', 'field_sqr', and 'field_div' can be used by 'add' and
147     * 'dbl' so that the same implementations of point operations can be used
148     * with different optimized implementations of expensive field
149     * operations:
150     */
151    int (*field_mul) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
152                      const BIGNUM *b, BN_CTX *);
153    int (*field_sqr) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a, BN_CTX *);
154    int (*field_div) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
155                      const BIGNUM *b, BN_CTX *);
156    /*-
157     * 'field_inv' computes the multiplicative inverse of a in the field,
158     * storing the result in r.
159     *
160     * If 'a' is zero (or equivalent), you'll get an EC_R_CANNOT_INVERT error.
161     */
162    int (*field_inv) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a, BN_CTX *);
163    /* e.g. to Montgomery */
164    int (*field_encode) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
165                         BN_CTX *);
166    /* e.g. from Montgomery */
167    int (*field_decode) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
168                         BN_CTX *);
169    int (*field_set_to_one) (const EC_GROUP *, BIGNUM *r, BN_CTX *);
170    /* private key operations */
171    size_t (*priv2oct)(const EC_KEY *eckey, unsigned char *buf, size_t len);
172    int (*oct2priv)(EC_KEY *eckey, const unsigned char *buf, size_t len);
173    int (*set_private)(EC_KEY *eckey, const BIGNUM *priv_key);
174    int (*keygen)(EC_KEY *eckey);
175    int (*keycheck)(const EC_KEY *eckey);
176    int (*keygenpub)(EC_KEY *eckey);
177    int (*keycopy)(EC_KEY *dst, const EC_KEY *src);
178    void (*keyfinish)(EC_KEY *eckey);
179    /* custom ECDH operation */
180    int (*ecdh_compute_key)(unsigned char **pout, size_t *poutlen,
181                            const EC_POINT *pub_key, const EC_KEY *ecdh);
182    /* Inverse modulo order */
183    int (*field_inverse_mod_ord)(const EC_GROUP *, BIGNUM *r,
184                                 const BIGNUM *x, BN_CTX *);
185    int (*blind_coordinates)(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx);
186    int (*ladder_pre)(const EC_GROUP *group,
187                      EC_POINT *r, EC_POINT *s,
188                      EC_POINT *p, BN_CTX *ctx);
189    int (*ladder_step)(const EC_GROUP *group,
190                       EC_POINT *r, EC_POINT *s,
191                       EC_POINT *p, BN_CTX *ctx);
192    int (*ladder_post)(const EC_GROUP *group,
193                       EC_POINT *r, EC_POINT *s,
194                       EC_POINT *p, BN_CTX *ctx);
195};
196
197/*
198 * Types and functions to manipulate pre-computed values.
199 */
200typedef struct nistp224_pre_comp_st NISTP224_PRE_COMP;
201typedef struct nistp256_pre_comp_st NISTP256_PRE_COMP;
202typedef struct nistp521_pre_comp_st NISTP521_PRE_COMP;
203typedef struct nistz256_pre_comp_st NISTZ256_PRE_COMP;
204typedef struct ec_pre_comp_st EC_PRE_COMP;
205
206struct ec_group_st {
207    const EC_METHOD *meth;
208    EC_POINT *generator;        /* optional */
209    BIGNUM *order, *cofactor;
210    int curve_name;             /* optional NID for named curve */
211    int asn1_flag;              /* flag to control the asn1 encoding */
212    point_conversion_form_t asn1_form;
213    unsigned char *seed;        /* optional seed for parameters (appears in
214                                 * ASN1) */
215    size_t seed_len;
216    /*
217     * The following members are handled by the method functions, even if
218     * they appear generic
219     */
220    /*
221     * Field specification. For curves over GF(p), this is the modulus; for
222     * curves over GF(2^m), this is the irreducible polynomial defining the
223     * field.
224     */
225    BIGNUM *field;
226    /*
227     * Field specification for curves over GF(2^m). The irreducible f(t) is
228     * then of the form: t^poly[0] + t^poly[1] + ... + t^poly[k] where m =
229     * poly[0] > poly[1] > ... > poly[k] = 0. The array is terminated with
230     * poly[k+1]=-1. All elliptic curve irreducibles have at most 5 non-zero
231     * terms.
232     */
233    int poly[6];
234    /*
235     * Curve coefficients. (Here the assumption is that BIGNUMs can be used
236     * or abused for all kinds of fields, not just GF(p).) For characteristic
237     * > 3, the curve is defined by a Weierstrass equation of the form y^2 =
238     * x^3 + a*x + b. For characteristic 2, the curve is defined by an
239     * equation of the form y^2 + x*y = x^3 + a*x^2 + b.
240     */
241    BIGNUM *a, *b;
242    /* enable optimized point arithmetics for special case */
243    int a_is_minus3;
244    /* method-specific (e.g., Montgomery structure) */
245    void *field_data1;
246    /* method-specific */
247    void *field_data2;
248    /* method-specific */
249    int (*field_mod_func) (BIGNUM *, const BIGNUM *, const BIGNUM *,
250                           BN_CTX *);
251    /* data for ECDSA inverse */
252    BN_MONT_CTX *mont_data;
253
254    /*
255     * Precomputed values for speed. The PCT_xxx names match the
256     * pre_comp.xxx union names; see the SETPRECOMP and HAVEPRECOMP
257     * macros, below.
258     */
259    enum {
260        PCT_none,
261        PCT_nistp224, PCT_nistp256, PCT_nistp521, PCT_nistz256,
262        PCT_ec
263    } pre_comp_type;
264    union {
265        NISTP224_PRE_COMP *nistp224;
266        NISTP256_PRE_COMP *nistp256;
267        NISTP521_PRE_COMP *nistp521;
268        NISTZ256_PRE_COMP *nistz256;
269        EC_PRE_COMP *ec;
270    } pre_comp;
271};
272
273#define SETPRECOMP(g, type, pre) \
274    g->pre_comp_type = PCT_##type, g->pre_comp.type = pre
275#define HAVEPRECOMP(g, type) \
276    g->pre_comp_type == PCT_##type && g->pre_comp.type != NULL
277
278struct ec_key_st {
279    const EC_KEY_METHOD *meth;
280    ENGINE *engine;
281    int version;
282    EC_GROUP *group;
283    EC_POINT *pub_key;
284    BIGNUM *priv_key;
285    unsigned int enc_flag;
286    point_conversion_form_t conv_form;
287    CRYPTO_REF_COUNT references;
288    int flags;
289    CRYPTO_EX_DATA ex_data;
290    CRYPTO_RWLOCK *lock;
291};
292
293struct ec_point_st {
294    const EC_METHOD *meth;
295    /* NID for the curve if known */
296    int curve_name;
297    /*
298     * All members except 'meth' are handled by the method functions, even if
299     * they appear generic
300     */
301    BIGNUM *X;
302    BIGNUM *Y;
303    BIGNUM *Z;                  /* Jacobian projective coordinates: * (X, Y,
304                                 * Z) represents (X/Z^2, Y/Z^3) if Z != 0 */
305    int Z_is_one;               /* enable optimized point arithmetics for
306                                 * special case */
307};
308
309static ossl_inline int ec_point_is_compat(const EC_POINT *point,
310                                          const EC_GROUP *group)
311{
312    if (group->meth != point->meth
313        || (group->curve_name != 0
314            && point->curve_name != 0
315            && group->curve_name != point->curve_name))
316        return 0;
317
318    return 1;
319}
320
321NISTP224_PRE_COMP *EC_nistp224_pre_comp_dup(NISTP224_PRE_COMP *);
322NISTP256_PRE_COMP *EC_nistp256_pre_comp_dup(NISTP256_PRE_COMP *);
323NISTP521_PRE_COMP *EC_nistp521_pre_comp_dup(NISTP521_PRE_COMP *);
324NISTZ256_PRE_COMP *EC_nistz256_pre_comp_dup(NISTZ256_PRE_COMP *);
325NISTP256_PRE_COMP *EC_nistp256_pre_comp_dup(NISTP256_PRE_COMP *);
326EC_PRE_COMP *EC_ec_pre_comp_dup(EC_PRE_COMP *);
327
328void EC_pre_comp_free(EC_GROUP *group);
329void EC_nistp224_pre_comp_free(NISTP224_PRE_COMP *);
330void EC_nistp256_pre_comp_free(NISTP256_PRE_COMP *);
331void EC_nistp521_pre_comp_free(NISTP521_PRE_COMP *);
332void EC_nistz256_pre_comp_free(NISTZ256_PRE_COMP *);
333void EC_ec_pre_comp_free(EC_PRE_COMP *);
334
335/*
336 * method functions in ec_mult.c (ec_lib.c uses these as defaults if
337 * group->method->mul is 0)
338 */
339int ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
340                size_t num, const EC_POINT *points[], const BIGNUM *scalars[],
341                BN_CTX *);
342int ec_wNAF_precompute_mult(EC_GROUP *group, BN_CTX *);
343int ec_wNAF_have_precompute_mult(const EC_GROUP *group);
344
345/* method functions in ecp_smpl.c */
346int ec_GFp_simple_group_init(EC_GROUP *);
347void ec_GFp_simple_group_finish(EC_GROUP *);
348void ec_GFp_simple_group_clear_finish(EC_GROUP *);
349int ec_GFp_simple_group_copy(EC_GROUP *, const EC_GROUP *);
350int ec_GFp_simple_group_set_curve(EC_GROUP *, const BIGNUM *p,
351                                  const BIGNUM *a, const BIGNUM *b, BN_CTX *);
352int ec_GFp_simple_group_get_curve(const EC_GROUP *, BIGNUM *p, BIGNUM *a,
353                                  BIGNUM *b, BN_CTX *);
354int ec_GFp_simple_group_get_degree(const EC_GROUP *);
355int ec_GFp_simple_group_check_discriminant(const EC_GROUP *, BN_CTX *);
356int ec_GFp_simple_point_init(EC_POINT *);
357void ec_GFp_simple_point_finish(EC_POINT *);
358void ec_GFp_simple_point_clear_finish(EC_POINT *);
359int ec_GFp_simple_point_copy(EC_POINT *, const EC_POINT *);
360int ec_GFp_simple_point_set_to_infinity(const EC_GROUP *, EC_POINT *);
361int ec_GFp_simple_set_Jprojective_coordinates_GFp(const EC_GROUP *,
362                                                  EC_POINT *, const BIGNUM *x,
363                                                  const BIGNUM *y,
364                                                  const BIGNUM *z, BN_CTX *);
365int ec_GFp_simple_get_Jprojective_coordinates_GFp(const EC_GROUP *,
366                                                  const EC_POINT *, BIGNUM *x,
367                                                  BIGNUM *y, BIGNUM *z,
368                                                  BN_CTX *);
369int ec_GFp_simple_point_set_affine_coordinates(const EC_GROUP *, EC_POINT *,
370                                               const BIGNUM *x,
371                                               const BIGNUM *y, BN_CTX *);
372int ec_GFp_simple_point_get_affine_coordinates(const EC_GROUP *,
373                                               const EC_POINT *, BIGNUM *x,
374                                               BIGNUM *y, BN_CTX *);
375int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *, EC_POINT *,
376                                             const BIGNUM *x, int y_bit,
377                                             BN_CTX *);
378size_t ec_GFp_simple_point2oct(const EC_GROUP *, const EC_POINT *,
379                               point_conversion_form_t form,
380                               unsigned char *buf, size_t len, BN_CTX *);
381int ec_GFp_simple_oct2point(const EC_GROUP *, EC_POINT *,
382                            const unsigned char *buf, size_t len, BN_CTX *);
383int ec_GFp_simple_add(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
384                      const EC_POINT *b, BN_CTX *);
385int ec_GFp_simple_dbl(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
386                      BN_CTX *);
387int ec_GFp_simple_invert(const EC_GROUP *, EC_POINT *, BN_CTX *);
388int ec_GFp_simple_is_at_infinity(const EC_GROUP *, const EC_POINT *);
389int ec_GFp_simple_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
390int ec_GFp_simple_cmp(const EC_GROUP *, const EC_POINT *a, const EC_POINT *b,
391                      BN_CTX *);
392int ec_GFp_simple_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
393int ec_GFp_simple_points_make_affine(const EC_GROUP *, size_t num,
394                                     EC_POINT *[], BN_CTX *);
395int ec_GFp_simple_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
396                            const BIGNUM *b, BN_CTX *);
397int ec_GFp_simple_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
398                            BN_CTX *);
399int ec_GFp_simple_field_inv(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
400                            BN_CTX *);
401int ec_GFp_simple_blind_coordinates(const EC_GROUP *group, EC_POINT *p,
402                                    BN_CTX *ctx);
403int ec_GFp_simple_ladder_pre(const EC_GROUP *group,
404                             EC_POINT *r, EC_POINT *s,
405                             EC_POINT *p, BN_CTX *ctx);
406int ec_GFp_simple_ladder_step(const EC_GROUP *group,
407                              EC_POINT *r, EC_POINT *s,
408                              EC_POINT *p, BN_CTX *ctx);
409int ec_GFp_simple_ladder_post(const EC_GROUP *group,
410                              EC_POINT *r, EC_POINT *s,
411                              EC_POINT *p, BN_CTX *ctx);
412
413/* method functions in ecp_mont.c */
414int ec_GFp_mont_group_init(EC_GROUP *);
415int ec_GFp_mont_group_set_curve(EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
416                                const BIGNUM *b, BN_CTX *);
417void ec_GFp_mont_group_finish(EC_GROUP *);
418void ec_GFp_mont_group_clear_finish(EC_GROUP *);
419int ec_GFp_mont_group_copy(EC_GROUP *, const EC_GROUP *);
420int ec_GFp_mont_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
421                          const BIGNUM *b, BN_CTX *);
422int ec_GFp_mont_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
423                          BN_CTX *);
424int ec_GFp_mont_field_inv(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
425                          BN_CTX *);
426int ec_GFp_mont_field_encode(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
427                             BN_CTX *);
428int ec_GFp_mont_field_decode(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
429                             BN_CTX *);
430int ec_GFp_mont_field_set_to_one(const EC_GROUP *, BIGNUM *r, BN_CTX *);
431
432/* method functions in ecp_nist.c */
433int ec_GFp_nist_group_copy(EC_GROUP *dest, const EC_GROUP *src);
434int ec_GFp_nist_group_set_curve(EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
435                                const BIGNUM *b, BN_CTX *);
436int ec_GFp_nist_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
437                          const BIGNUM *b, BN_CTX *);
438int ec_GFp_nist_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
439                          BN_CTX *);
440
441/* method functions in ec2_smpl.c */
442int ec_GF2m_simple_group_init(EC_GROUP *);
443void ec_GF2m_simple_group_finish(EC_GROUP *);
444void ec_GF2m_simple_group_clear_finish(EC_GROUP *);
445int ec_GF2m_simple_group_copy(EC_GROUP *, const EC_GROUP *);
446int ec_GF2m_simple_group_set_curve(EC_GROUP *, const BIGNUM *p,
447                                   const BIGNUM *a, const BIGNUM *b,
448                                   BN_CTX *);
449int ec_GF2m_simple_group_get_curve(const EC_GROUP *, BIGNUM *p, BIGNUM *a,
450                                   BIGNUM *b, BN_CTX *);
451int ec_GF2m_simple_group_get_degree(const EC_GROUP *);
452int ec_GF2m_simple_group_check_discriminant(const EC_GROUP *, BN_CTX *);
453int ec_GF2m_simple_point_init(EC_POINT *);
454void ec_GF2m_simple_point_finish(EC_POINT *);
455void ec_GF2m_simple_point_clear_finish(EC_POINT *);
456int ec_GF2m_simple_point_copy(EC_POINT *, const EC_POINT *);
457int ec_GF2m_simple_point_set_to_infinity(const EC_GROUP *, EC_POINT *);
458int ec_GF2m_simple_point_set_affine_coordinates(const EC_GROUP *, EC_POINT *,
459                                                const BIGNUM *x,
460                                                const BIGNUM *y, BN_CTX *);
461int ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *,
462                                                const EC_POINT *, BIGNUM *x,
463                                                BIGNUM *y, BN_CTX *);
464int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *, EC_POINT *,
465                                              const BIGNUM *x, int y_bit,
466                                              BN_CTX *);
467size_t ec_GF2m_simple_point2oct(const EC_GROUP *, const EC_POINT *,
468                                point_conversion_form_t form,
469                                unsigned char *buf, size_t len, BN_CTX *);
470int ec_GF2m_simple_oct2point(const EC_GROUP *, EC_POINT *,
471                             const unsigned char *buf, size_t len, BN_CTX *);
472int ec_GF2m_simple_add(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
473                       const EC_POINT *b, BN_CTX *);
474int ec_GF2m_simple_dbl(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
475                       BN_CTX *);
476int ec_GF2m_simple_invert(const EC_GROUP *, EC_POINT *, BN_CTX *);
477int ec_GF2m_simple_is_at_infinity(const EC_GROUP *, const EC_POINT *);
478int ec_GF2m_simple_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
479int ec_GF2m_simple_cmp(const EC_GROUP *, const EC_POINT *a, const EC_POINT *b,
480                       BN_CTX *);
481int ec_GF2m_simple_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
482int ec_GF2m_simple_points_make_affine(const EC_GROUP *, size_t num,
483                                      EC_POINT *[], BN_CTX *);
484int ec_GF2m_simple_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
485                             const BIGNUM *b, BN_CTX *);
486int ec_GF2m_simple_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
487                             BN_CTX *);
488int ec_GF2m_simple_field_div(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
489                             const BIGNUM *b, BN_CTX *);
490
491#ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
492/* method functions in ecp_nistp224.c */
493int ec_GFp_nistp224_group_init(EC_GROUP *group);
494int ec_GFp_nistp224_group_set_curve(EC_GROUP *group, const BIGNUM *p,
495                                    const BIGNUM *a, const BIGNUM *n,
496                                    BN_CTX *);
497int ec_GFp_nistp224_point_get_affine_coordinates(const EC_GROUP *group,
498                                                 const EC_POINT *point,
499                                                 BIGNUM *x, BIGNUM *y,
500                                                 BN_CTX *ctx);
501int ec_GFp_nistp224_mul(const EC_GROUP *group, EC_POINT *r,
502                        const BIGNUM *scalar, size_t num,
503                        const EC_POINT *points[], const BIGNUM *scalars[],
504                        BN_CTX *);
505int ec_GFp_nistp224_points_mul(const EC_GROUP *group, EC_POINT *r,
506                               const BIGNUM *scalar, size_t num,
507                               const EC_POINT *points[],
508                               const BIGNUM *scalars[], BN_CTX *ctx);
509int ec_GFp_nistp224_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
510int ec_GFp_nistp224_have_precompute_mult(const EC_GROUP *group);
511
512/* method functions in ecp_nistp256.c */
513int ec_GFp_nistp256_group_init(EC_GROUP *group);
514int ec_GFp_nistp256_group_set_curve(EC_GROUP *group, const BIGNUM *p,
515                                    const BIGNUM *a, const BIGNUM *n,
516                                    BN_CTX *);
517int ec_GFp_nistp256_point_get_affine_coordinates(const EC_GROUP *group,
518                                                 const EC_POINT *point,
519                                                 BIGNUM *x, BIGNUM *y,
520                                                 BN_CTX *ctx);
521int ec_GFp_nistp256_mul(const EC_GROUP *group, EC_POINT *r,
522                        const BIGNUM *scalar, size_t num,
523                        const EC_POINT *points[], const BIGNUM *scalars[],
524                        BN_CTX *);
525int ec_GFp_nistp256_points_mul(const EC_GROUP *group, EC_POINT *r,
526                               const BIGNUM *scalar, size_t num,
527                               const EC_POINT *points[],
528                               const BIGNUM *scalars[], BN_CTX *ctx);
529int ec_GFp_nistp256_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
530int ec_GFp_nistp256_have_precompute_mult(const EC_GROUP *group);
531
532/* method functions in ecp_nistp521.c */
533int ec_GFp_nistp521_group_init(EC_GROUP *group);
534int ec_GFp_nistp521_group_set_curve(EC_GROUP *group, const BIGNUM *p,
535                                    const BIGNUM *a, const BIGNUM *n,
536                                    BN_CTX *);
537int ec_GFp_nistp521_point_get_affine_coordinates(const EC_GROUP *group,
538                                                 const EC_POINT *point,
539                                                 BIGNUM *x, BIGNUM *y,
540                                                 BN_CTX *ctx);
541int ec_GFp_nistp521_mul(const EC_GROUP *group, EC_POINT *r,
542                        const BIGNUM *scalar, size_t num,
543                        const EC_POINT *points[], const BIGNUM *scalars[],
544                        BN_CTX *);
545int ec_GFp_nistp521_points_mul(const EC_GROUP *group, EC_POINT *r,
546                               const BIGNUM *scalar, size_t num,
547                               const EC_POINT *points[],
548                               const BIGNUM *scalars[], BN_CTX *ctx);
549int ec_GFp_nistp521_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
550int ec_GFp_nistp521_have_precompute_mult(const EC_GROUP *group);
551
552/* utility functions in ecp_nistputil.c */
553void ec_GFp_nistp_points_make_affine_internal(size_t num, void *point_array,
554                                              size_t felem_size,
555                                              void *tmp_felems,
556                                              void (*felem_one) (void *out),
557                                              int (*felem_is_zero) (const void
558                                                                    *in),
559                                              void (*felem_assign) (void *out,
560                                                                    const void
561                                                                    *in),
562                                              void (*felem_square) (void *out,
563                                                                    const void
564                                                                    *in),
565                                              void (*felem_mul) (void *out,
566                                                                 const void
567                                                                 *in1,
568                                                                 const void
569                                                                 *in2),
570                                              void (*felem_inv) (void *out,
571                                                                 const void
572                                                                 *in),
573                                              void (*felem_contract) (void
574                                                                      *out,
575                                                                      const
576                                                                      void
577                                                                      *in));
578void ec_GFp_nistp_recode_scalar_bits(unsigned char *sign,
579                                     unsigned char *digit, unsigned char in);
580#endif
581int ec_group_simple_order_bits(const EC_GROUP *group);
582
583#ifdef ECP_NISTZ256_ASM
584/** Returns GFp methods using montgomery multiplication, with x86-64 optimized
585 * P256. See http://eprint.iacr.org/2013/816.
586 *  \return  EC_METHOD object
587 */
588const EC_METHOD *EC_GFp_nistz256_method(void);
589#endif
590
591size_t ec_key_simple_priv2oct(const EC_KEY *eckey,
592                              unsigned char *buf, size_t len);
593int ec_key_simple_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len);
594int ec_key_simple_generate_key(EC_KEY *eckey);
595int ec_key_simple_generate_public_key(EC_KEY *eckey);
596int ec_key_simple_check_key(const EC_KEY *eckey);
597
598int ec_curve_nid_from_params(const EC_GROUP *group, BN_CTX *ctx);
599
600/* EC_METHOD definitions */
601
602struct ec_key_method_st {
603    const char *name;
604    int32_t flags;
605    int (*init)(EC_KEY *key);
606    void (*finish)(EC_KEY *key);
607    int (*copy)(EC_KEY *dest, const EC_KEY *src);
608    int (*set_group)(EC_KEY *key, const EC_GROUP *grp);
609    int (*set_private)(EC_KEY *key, const BIGNUM *priv_key);
610    int (*set_public)(EC_KEY *key, const EC_POINT *pub_key);
611    int (*keygen)(EC_KEY *key);
612    int (*compute_key)(unsigned char **pout, size_t *poutlen,
613                       const EC_POINT *pub_key, const EC_KEY *ecdh);
614    int (*sign)(int type, const unsigned char *dgst, int dlen, unsigned char
615                *sig, unsigned int *siglen, const BIGNUM *kinv,
616                const BIGNUM *r, EC_KEY *eckey);
617    int (*sign_setup)(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
618                      BIGNUM **rp);
619    ECDSA_SIG *(*sign_sig)(const unsigned char *dgst, int dgst_len,
620                           const BIGNUM *in_kinv, const BIGNUM *in_r,
621                           EC_KEY *eckey);
622
623    int (*verify)(int type, const unsigned char *dgst, int dgst_len,
624                  const unsigned char *sigbuf, int sig_len, EC_KEY *eckey);
625    int (*verify_sig)(const unsigned char *dgst, int dgst_len,
626                      const ECDSA_SIG *sig, EC_KEY *eckey);
627};
628
629#define EC_KEY_METHOD_DYNAMIC   1
630
631int ossl_ec_key_gen(EC_KEY *eckey);
632int ossl_ecdh_compute_key(unsigned char **pout, size_t *poutlen,
633                          const EC_POINT *pub_key, const EC_KEY *ecdh);
634int ecdh_simple_compute_key(unsigned char **pout, size_t *poutlen,
635                            const EC_POINT *pub_key, const EC_KEY *ecdh);
636
637struct ECDSA_SIG_st {
638    BIGNUM *r;
639    BIGNUM *s;
640};
641
642int ossl_ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
643                          BIGNUM **rp);
644int ossl_ecdsa_sign(int type, const unsigned char *dgst, int dlen,
645                    unsigned char *sig, unsigned int *siglen,
646                    const BIGNUM *kinv, const BIGNUM *r, EC_KEY *eckey);
647ECDSA_SIG *ossl_ecdsa_sign_sig(const unsigned char *dgst, int dgst_len,
648                               const BIGNUM *in_kinv, const BIGNUM *in_r,
649                               EC_KEY *eckey);
650int ossl_ecdsa_verify(int type, const unsigned char *dgst, int dgst_len,
651                      const unsigned char *sigbuf, int sig_len, EC_KEY *eckey);
652int ossl_ecdsa_verify_sig(const unsigned char *dgst, int dgst_len,
653                          const ECDSA_SIG *sig, EC_KEY *eckey);
654
655int ED25519_sign(uint8_t *out_sig, const uint8_t *message, size_t message_len,
656                 const uint8_t public_key[32], const uint8_t private_key[32]);
657int ED25519_verify(const uint8_t *message, size_t message_len,
658                   const uint8_t signature[64], const uint8_t public_key[32]);
659void ED25519_public_from_private(uint8_t out_public_key[32],
660                                 const uint8_t private_key[32]);
661
662int X25519(uint8_t out_shared_key[32], const uint8_t private_key[32],
663           const uint8_t peer_public_value[32]);
664void X25519_public_from_private(uint8_t out_public_value[32],
665                                const uint8_t private_key[32]);
666
667/*-
668 * This functions computes a single point multiplication over the EC group,
669 * using, at a high level, a Montgomery ladder with conditional swaps, with
670 * various timing attack defenses.
671 *
672 * It performs either a fixed point multiplication
673 *          (scalar * generator)
674 * when point is NULL, or a variable point multiplication
675 *          (scalar * point)
676 * when point is not NULL.
677 *
678 * `scalar` cannot be NULL and should be in the range [0,n) otherwise all
679 * constant time bets are off (where n is the cardinality of the EC group).
680 *
681 * This function expects `group->order` and `group->cardinality` to be well
682 * defined and non-zero: it fails with an error code otherwise.
683 *
684 * NB: This says nothing about the constant-timeness of the ladder step
685 * implementation (i.e., the default implementation is based on EC_POINT_add and
686 * EC_POINT_dbl, which of course are not constant time themselves) or the
687 * underlying multiprecision arithmetic.
688 *
689 * The product is stored in `r`.
690 *
691 * This is an internal function: callers are in charge of ensuring that the
692 * input parameters `group`, `r`, `scalar` and `ctx` are not NULL.
693 *
694 * Returns 1 on success, 0 otherwise.
695 */
696int ec_scalar_mul_ladder(const EC_GROUP *group, EC_POINT *r,
697                         const BIGNUM *scalar, const EC_POINT *point,
698                         BN_CTX *ctx);
699
700int ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx);
701
702static ossl_inline int ec_point_ladder_pre(const EC_GROUP *group,
703                                           EC_POINT *r, EC_POINT *s,
704                                           EC_POINT *p, BN_CTX *ctx)
705{
706    if (group->meth->ladder_pre != NULL)
707        return group->meth->ladder_pre(group, r, s, p, ctx);
708
709    if (!EC_POINT_copy(s, p)
710        || !EC_POINT_dbl(group, r, s, ctx))
711        return 0;
712
713    return 1;
714}
715
716static ossl_inline int ec_point_ladder_step(const EC_GROUP *group,
717                                            EC_POINT *r, EC_POINT *s,
718                                            EC_POINT *p, BN_CTX *ctx)
719{
720    if (group->meth->ladder_step != NULL)
721        return group->meth->ladder_step(group, r, s, p, ctx);
722
723    if (!EC_POINT_add(group, s, r, s, ctx)
724        || !EC_POINT_dbl(group, r, r, ctx))
725        return 0;
726
727    return 1;
728
729}
730
731static ossl_inline int ec_point_ladder_post(const EC_GROUP *group,
732                                            EC_POINT *r, EC_POINT *s,
733                                            EC_POINT *p, BN_CTX *ctx)
734{
735    if (group->meth->ladder_post != NULL)
736        return group->meth->ladder_post(group, r, s, p, ctx);
737
738    return 1;
739}
740