crypto/ec/ec_local.h

   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
  39 struct 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  */
 200 typedef struct nistp224_pre_comp_st NISTP224_PRE_COMP;
 201 typedef struct nistp256_pre_comp_st NISTP256_PRE_COMP;
 202 typedef struct nistp521_pre_comp_st NISTP521_PRE_COMP;
 203 typedef struct nistz256_pre_comp_st NISTZ256_PRE_COMP;
 204 typedef struct ec_pre_comp_st EC_PRE_COMP;
 205
 206 struct 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
 278 struct 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
 293 struct 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
 309 static 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
 321 NISTP224_PRE_COMP *EC_nistp224_pre_comp_dup(NISTP224_PRE_COMP *);
 322 NISTP256_PRE_COMP *EC_nistp256_pre_comp_dup(NISTP256_PRE_COMP *);
 323 NISTP521_PRE_COMP *EC_nistp521_pre_comp_dup(NISTP521_PRE_COMP *);
 324 NISTZ256_PRE_COMP *EC_nistz256_pre_comp_dup(NISTZ256_PRE_COMP *);
 325 NISTP256_PRE_COMP *EC_nistp256_pre_comp_dup(NISTP256_PRE_COMP *);
 326 EC_PRE_COMP *EC_ec_pre_comp_dup(EC_PRE_COMP *);
 327
 328 void EC_pre_comp_free(EC_GROUP *group);
 329 void EC_nistp224_pre_comp_free(NISTP224_PRE_COMP *);
 330 void EC_nistp256_pre_comp_free(NISTP256_PRE_COMP *);
 331 void EC_nistp521_pre_comp_free(NISTP521_PRE_COMP *);
 332 void EC_nistz256_pre_comp_free(NISTZ256_PRE_COMP *);
 333 void 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  */
 339 int 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 *);
 342 int ec_wNAF_precompute_mult(EC_GROUP *group, BN_CTX *);
 343 int ec_wNAF_have_precompute_mult(const EC_GROUP *group);
 344
 345 /* method functions in ecp_smpl.c */
 346 int ec_GFp_simple_group_init(EC_GROUP *);
 347 void ec_GFp_simple_group_finish(EC_GROUP *);
 348 void ec_GFp_simple_group_clear_finish(EC_GROUP *);
 349 int ec_GFp_simple_group_copy(EC_GROUP *, const EC_GROUP *);
 350 int ec_GFp_simple_group_set_curve(EC_GROUP *, const BIGNUM *p,
 351                                   const BIGNUM *a, const BIGNUM *b, BN_CTX *);
 352 int ec_GFp_simple_group_get_curve(const EC_GROUP *, BIGNUM *p, BIGNUM *a,
 353                                   BIGNUM *b, BN_CTX *);
 354 int ec_GFp_simple_group_get_degree(const EC_GROUP *);
 355 int ec_GFp_simple_group_check_discriminant(const EC_GROUP *, BN_CTX *);
 356 int ec_GFp_simple_point_init(EC_POINT *);
 357 void ec_GFp_simple_point_finish(EC_POINT *);
 358 void ec_GFp_simple_point_clear_finish(EC_POINT *);
 359 int ec_GFp_simple_point_copy(EC_POINT *, const EC_POINT *);
 360 int ec_GFp_simple_point_set_to_infinity(const EC_GROUP *, EC_POINT *);
 361 int 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 *);
 365 int ec_GFp_simple_get_Jprojective_coordinates_GFp(const EC_GROUP *,
 366                                                   const EC_POINT *, BIGNUM *x,
 367                                                   BIGNUM *y, BIGNUM *z,
 368                                                   BN_CTX *);
 369 int ec_GFp_simple_point_set_affine_coordinates(const EC_GROUP *, EC_POINT *,
 370                                                const BIGNUM *x,
 371                                                const BIGNUM *y, BN_CTX *);
 372 int ec_GFp_simple_point_get_affine_coordinates(const EC_GROUP *,
 373                                                const EC_POINT *, BIGNUM *x,
 374                                                BIGNUM *y, BN_CTX *);
 375 int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *, EC_POINT *,
 376                                              const BIGNUM *x, int y_bit,
 377                                              BN_CTX *);
 378 size_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 *);
 381 int ec_GFp_simple_oct2point(const EC_GROUP *, EC_POINT *,
 382                             const unsigned char *buf, size_t len, BN_CTX *);
 383 int ec_GFp_simple_add(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
 384                       const EC_POINT *b, BN_CTX *);
 385 int ec_GFp_simple_dbl(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
 386                       BN_CTX *);
 387 int ec_GFp_simple_invert(const EC_GROUP *, EC_POINT *, BN_CTX *);
 388 int ec_GFp_simple_is_at_infinity(const EC_GROUP *, const EC_POINT *);
 389 int ec_GFp_simple_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
 390 int ec_GFp_simple_cmp(const EC_GROUP *, const EC_POINT *a, const EC_POINT *b,
 391                       BN_CTX *);
 392 int ec_GFp_simple_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
 393 int ec_GFp_simple_points_make_affine(const EC_GROUP *, size_t num,
 394                                      EC_POINT *[], BN_CTX *);
 395 int ec_GFp_simple_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 396                             const BIGNUM *b, BN_CTX *);
 397 int ec_GFp_simple_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 398                             BN_CTX *);
 399 int ec_GFp_simple_field_inv(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 400                             BN_CTX *);
 401 int ec_GFp_simple_blind_coordinates(const EC_GROUP *group, EC_POINT *p,
 402                                     BN_CTX *ctx);
 403 int ec_GFp_simple_ladder_pre(const EC_GROUP *group,
 404                              EC_POINT *r, EC_POINT *s,
 405                              EC_POINT *p, BN_CTX *ctx);
 406 int ec_GFp_simple_ladder_step(const EC_GROUP *group,
 407                               EC_POINT *r, EC_POINT *s,
 408                               EC_POINT *p, BN_CTX *ctx);
 409 int 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 */
 414 int ec_GFp_mont_group_init(EC_GROUP *);
 415 int ec_GFp_mont_group_set_curve(EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
 416                                 const BIGNUM *b, BN_CTX *);
 417 void ec_GFp_mont_group_finish(EC_GROUP *);
 418 void ec_GFp_mont_group_clear_finish(EC_GROUP *);
 419 int ec_GFp_mont_group_copy(EC_GROUP *, const EC_GROUP *);
 420 int ec_GFp_mont_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 421                           const BIGNUM *b, BN_CTX *);
 422 int ec_GFp_mont_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 423                           BN_CTX *);
 424 int ec_GFp_mont_field_inv(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 425                           BN_CTX *);
 426 int ec_GFp_mont_field_encode(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 427                              BN_CTX *);
 428 int ec_GFp_mont_field_decode(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 429                              BN_CTX *);
 430 int ec_GFp_mont_field_set_to_one(const EC_GROUP *, BIGNUM *r, BN_CTX *);
 431
 432 /* method functions in ecp_nist.c */
 433 int ec_GFp_nist_group_copy(EC_GROUP *dest, const EC_GROUP *src);
 434 int ec_GFp_nist_group_set_curve(EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
 435                                 const BIGNUM *b, BN_CTX *);
 436 int ec_GFp_nist_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 437                           const BIGNUM *b, BN_CTX *);
 438 int ec_GFp_nist_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 439                           BN_CTX *);
 440
 441 /* method functions in ec2_smpl.c */
 442 int ec_GF2m_simple_group_init(EC_GROUP *);
 443 void ec_GF2m_simple_group_finish(EC_GROUP *);
 444 void ec_GF2m_simple_group_clear_finish(EC_GROUP *);
 445 int ec_GF2m_simple_group_copy(EC_GROUP *, const EC_GROUP *);
 446 int ec_GF2m_simple_group_set_curve(EC_GROUP *, const BIGNUM *p,
 447                                    const BIGNUM *a, const BIGNUM *b,
 448                                    BN_CTX *);
 449 int ec_GF2m_simple_group_get_curve(const EC_GROUP *, BIGNUM *p, BIGNUM *a,
 450                                    BIGNUM *b, BN_CTX *);
 451 int ec_GF2m_simple_group_get_degree(const EC_GROUP *);
 452 int ec_GF2m_simple_group_check_discriminant(const EC_GROUP *, BN_CTX *);
 453 int ec_GF2m_simple_point_init(EC_POINT *);
 454 void ec_GF2m_simple_point_finish(EC_POINT *);
 455 void ec_GF2m_simple_point_clear_finish(EC_POINT *);
 456 int ec_GF2m_simple_point_copy(EC_POINT *, const EC_POINT *);
 457 int ec_GF2m_simple_point_set_to_infinity(const EC_GROUP *, EC_POINT *);
 458 int ec_GF2m_simple_point_set_affine_coordinates(const EC_GROUP *, EC_POINT *,
 459                                                 const BIGNUM *x,
 460                                                 const BIGNUM *y, BN_CTX *);
 461 int ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *,
 462                                                 const EC_POINT *, BIGNUM *x,
 463                                                 BIGNUM *y, BN_CTX *);
 464 int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *, EC_POINT *,
 465                                               const BIGNUM *x, int y_bit,
 466                                               BN_CTX *);
 467 size_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 *);
 470 int ec_GF2m_simple_oct2point(const EC_GROUP *, EC_POINT *,
 471                              const unsigned char *buf, size_t len, BN_CTX *);
 472 int ec_GF2m_simple_add(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
 473                        const EC_POINT *b, BN_CTX *);
 474 int ec_GF2m_simple_dbl(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
 475                        BN_CTX *);
 476 int ec_GF2m_simple_invert(const EC_GROUP *, EC_POINT *, BN_CTX *);
 477 int ec_GF2m_simple_is_at_infinity(const EC_GROUP *, const EC_POINT *);
 478 int ec_GF2m_simple_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
 479 int ec_GF2m_simple_cmp(const EC_GROUP *, const EC_POINT *a, const EC_POINT *b,
 480                        BN_CTX *);
 481 int ec_GF2m_simple_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
 482 int ec_GF2m_simple_points_make_affine(const EC_GROUP *, size_t num,
 483                                       EC_POINT *[], BN_CTX *);
 484 int ec_GF2m_simple_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 485                              const BIGNUM *b, BN_CTX *);
 486 int ec_GF2m_simple_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 487                              BN_CTX *);
 488 int 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 */
 493 int ec_GFp_nistp224_group_init(EC_GROUP *group);
 494 int ec_GFp_nistp224_group_set_curve(EC_GROUP *group, const BIGNUM *p,
 495                                     const BIGNUM *a, const BIGNUM *n,
 496                                     BN_CTX *);
 497 int 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);
 501 int 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 *);
 505 int 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);
 509 int ec_GFp_nistp224_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
 510 int ec_GFp_nistp224_have_precompute_mult(const EC_GROUP *group);
 511
 512 /* method functions in ecp_nistp256.c */
 513 int ec_GFp_nistp256_group_init(EC_GROUP *group);
 514 int ec_GFp_nistp256_group_set_curve(EC_GROUP *group, const BIGNUM *p,
 515                                     const BIGNUM *a, const BIGNUM *n,
 516                                     BN_CTX *);
 517 int 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);
 521 int 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 *);
 525 int 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);
 529 int ec_GFp_nistp256_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
 530 int ec_GFp_nistp256_have_precompute_mult(const EC_GROUP *group);
 531
 532 /* method functions in ecp_nistp521.c */
 533 int ec_GFp_nistp521_group_init(EC_GROUP *group);
 534 int ec_GFp_nistp521_group_set_curve(EC_GROUP *group, const BIGNUM *p,
 535                                     const BIGNUM *a, const BIGNUM *n,
 536                                     BN_CTX *);
 537 int 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);
 541 int 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 *);
 545 int 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);
 549 int ec_GFp_nistp521_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
 550 int ec_GFp_nistp521_have_precompute_mult(const EC_GROUP *group);
 551
 552 /* utility functions in ecp_nistputil.c */
 553 void 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));
 578 void ec_GFp_nistp_recode_scalar_bits(unsigned char *sign,
 579                                      unsigned char *digit, unsigned char in);
 580 #endif
 581 int 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  */
 588 const EC_METHOD *EC_GFp_nistz256_method(void);
 589 #endif
 590
 591 size_t ec_key_simple_priv2oct(const EC_KEY *eckey,
 592                               unsigned char *buf, size_t len);
 593 int ec_key_simple_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len);
 594 int ec_key_simple_generate_key(EC_KEY *eckey);
 595 int ec_key_simple_generate_public_key(EC_KEY *eckey);
 596 int ec_key_simple_check_key(const EC_KEY *eckey);
 597
 598 int ec_curve_nid_from_params(const EC_GROUP *group, BN_CTX *ctx);
 599
 600 /* EC_METHOD definitions */
 601
 602 struct 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
 631 int ossl_ec_key_gen(EC_KEY *eckey);
 632 int ossl_ecdh_compute_key(unsigned char **pout, size_t *poutlen,
 633                           const EC_POINT *pub_key, const EC_KEY *ecdh);
 634 int ecdh_simple_compute_key(unsigned char **pout, size_t *poutlen,
 635                             const EC_POINT *pub_key, const EC_KEY *ecdh);
 636
 637 struct ECDSA_SIG_st {
 638     BIGNUM *r;
 639     BIGNUM *s;
 640 };
 641
 642 int ossl_ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
 643                           BIGNUM **rp);
 644 int 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);
 647 ECDSA_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);
 650 int ossl_ecdsa_verify(int type, const unsigned char *dgst, int dgst_len,
 651                       const unsigned char *sigbuf, int sig_len, EC_KEY *eckey);
 652 int ossl_ecdsa_verify_sig(const unsigned char *dgst, int dgst_len,
 653                           const ECDSA_SIG *sig, EC_KEY *eckey);
 654
 655 int 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]);
 657 int ED25519_verify(const uint8_t *message, size_t message_len,
 658                    const uint8_t signature[64], const uint8_t public_key[32]);
 659 void ED25519_public_from_private(uint8_t out_public_key[32],
 660                                  const uint8_t private_key[32]);
 661
 662 int X25519(uint8_t out_shared_key[32], const uint8_t private_key[32],
 663            const uint8_t peer_public_value[32]);
 664 void 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  */
 696 int ec_scalar_mul_ladder(const EC_GROUP *group, EC_POINT *r,
 697                          const BIGNUM *scalar, const EC_POINT *point,
 698                          BN_CTX *ctx);
 699
 700 int ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx);
 701
 702 static 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
 716 static 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
 731 static 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 }