crypto/ec/ec_local.h

   1 /*
   2  * Copyright 2001-2020 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
 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 ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
 353                 size_t num, const EC_POINT *points[], const BIGNUM *scalars[],
 354                 BN_CTX *);
 355 int ec_wNAF_precompute_mult(EC_GROUP *group, BN_CTX *);
 356 int ec_wNAF_have_precompute_mult(const EC_GROUP *group);
 357
 358 /* method functions in ecp_smpl.c */
 359 int ec_GFp_simple_group_init(EC_GROUP *);
 360 void ec_GFp_simple_group_finish(EC_GROUP *);
 361 void ec_GFp_simple_group_clear_finish(EC_GROUP *);
 362 int ec_GFp_simple_group_copy(EC_GROUP *, const EC_GROUP *);
 363 int ec_GFp_simple_group_set_curve(EC_GROUP *, const BIGNUM *p,
 364                                   const BIGNUM *a, const BIGNUM *b, BN_CTX *);
 365 int ec_GFp_simple_group_get_curve(const EC_GROUP *, BIGNUM *p, BIGNUM *a,
 366                                   BIGNUM *b, BN_CTX *);
 367 int ec_GFp_simple_group_get_degree(const EC_GROUP *);
 368 int ec_GFp_simple_group_check_discriminant(const EC_GROUP *, BN_CTX *);
 369 int ec_GFp_simple_point_init(EC_POINT *);
 370 void ec_GFp_simple_point_finish(EC_POINT *);
 371 void ec_GFp_simple_point_clear_finish(EC_POINT *);
 372 int ec_GFp_simple_point_copy(EC_POINT *, const EC_POINT *);
 373 int ec_GFp_simple_point_set_to_infinity(const EC_GROUP *, EC_POINT *);
 374 int ec_GFp_simple_set_Jprojective_coordinates_GFp(const EC_GROUP *,
 375                                                   EC_POINT *, const BIGNUM *x,
 376                                                   const BIGNUM *y,
 377                                                   const BIGNUM *z, BN_CTX *);
 378 int ec_GFp_simple_get_Jprojective_coordinates_GFp(const EC_GROUP *,
 379                                                   const EC_POINT *, BIGNUM *x,
 380                                                   BIGNUM *y, BIGNUM *z,
 381                                                   BN_CTX *);
 382 int ec_GFp_simple_point_set_affine_coordinates(const EC_GROUP *, EC_POINT *,
 383                                                const BIGNUM *x,
 384                                                const BIGNUM *y, BN_CTX *);
 385 int ec_GFp_simple_point_get_affine_coordinates(const EC_GROUP *,
 386                                                const EC_POINT *, BIGNUM *x,
 387                                                BIGNUM *y, BN_CTX *);
 388 int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *, EC_POINT *,
 389                                              const BIGNUM *x, int y_bit,
 390                                              BN_CTX *);
 391 size_t ec_GFp_simple_point2oct(const EC_GROUP *, const EC_POINT *,
 392                                point_conversion_form_t form,
 393                                unsigned char *buf, size_t len, BN_CTX *);
 394 int ec_GFp_simple_oct2point(const EC_GROUP *, EC_POINT *,
 395                             const unsigned char *buf, size_t len, BN_CTX *);
 396 int ec_GFp_simple_add(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
 397                       const EC_POINT *b, BN_CTX *);
 398 int ec_GFp_simple_dbl(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
 399                       BN_CTX *);
 400 int ec_GFp_simple_invert(const EC_GROUP *, EC_POINT *, BN_CTX *);
 401 int ec_GFp_simple_is_at_infinity(const EC_GROUP *, const EC_POINT *);
 402 int ec_GFp_simple_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
 403 int ec_GFp_simple_cmp(const EC_GROUP *, const EC_POINT *a, const EC_POINT *b,
 404                       BN_CTX *);
 405 int ec_GFp_simple_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
 406 int ec_GFp_simple_points_make_affine(const EC_GROUP *, size_t num,
 407                                      EC_POINT *[], BN_CTX *);
 408 int ec_GFp_simple_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 409                             const BIGNUM *b, BN_CTX *);
 410 int ec_GFp_simple_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 411                             BN_CTX *);
 412 int ec_GFp_simple_field_inv(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 413                             BN_CTX *);
 414 int ec_GFp_simple_blind_coordinates(const EC_GROUP *group, EC_POINT *p,
 415                                     BN_CTX *ctx);
 416 int ec_GFp_simple_ladder_pre(const EC_GROUP *group,
 417                              EC_POINT *r, EC_POINT *s,
 418                              EC_POINT *p, BN_CTX *ctx);
 419 int ec_GFp_simple_ladder_step(const EC_GROUP *group,
 420                               EC_POINT *r, EC_POINT *s,
 421                               EC_POINT *p, BN_CTX *ctx);
 422 int ec_GFp_simple_ladder_post(const EC_GROUP *group,
 423                               EC_POINT *r, EC_POINT *s,
 424                               EC_POINT *p, BN_CTX *ctx);
 425
 426 /* method functions in ecp_mont.c */
 427 int ec_GFp_mont_group_init(EC_GROUP *);
 428 int ec_GFp_mont_group_set_curve(EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
 429                                 const BIGNUM *b, BN_CTX *);
 430 void ec_GFp_mont_group_finish(EC_GROUP *);
 431 void ec_GFp_mont_group_clear_finish(EC_GROUP *);
 432 int ec_GFp_mont_group_copy(EC_GROUP *, const EC_GROUP *);
 433 int ec_GFp_mont_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 434                           const BIGNUM *b, BN_CTX *);
 435 int ec_GFp_mont_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 436                           BN_CTX *);
 437 int ec_GFp_mont_field_inv(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 438                           BN_CTX *);
 439 int ec_GFp_mont_field_encode(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 440                              BN_CTX *);
 441 int ec_GFp_mont_field_decode(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 442                              BN_CTX *);
 443 int ec_GFp_mont_field_set_to_one(const EC_GROUP *, BIGNUM *r, BN_CTX *);
 444
 445 /* method functions in ecp_nist.c */
 446 int ec_GFp_nist_group_copy(EC_GROUP *dest, const EC_GROUP *src);
 447 int ec_GFp_nist_group_set_curve(EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
 448                                 const BIGNUM *b, BN_CTX *);
 449 int ec_GFp_nist_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 450                           const BIGNUM *b, BN_CTX *);
 451 int ec_GFp_nist_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 452                           BN_CTX *);
 453
 454 /* method functions in ec2_smpl.c */
 455 int ec_GF2m_simple_group_init(EC_GROUP *);
 456 void ec_GF2m_simple_group_finish(EC_GROUP *);
 457 void ec_GF2m_simple_group_clear_finish(EC_GROUP *);
 458 int ec_GF2m_simple_group_copy(EC_GROUP *, const EC_GROUP *);
 459 int ec_GF2m_simple_group_set_curve(EC_GROUP *, const BIGNUM *p,
 460                                    const BIGNUM *a, const BIGNUM *b,
 461                                    BN_CTX *);
 462 int ec_GF2m_simple_group_get_curve(const EC_GROUP *, BIGNUM *p, BIGNUM *a,
 463                                    BIGNUM *b, BN_CTX *);
 464 int ec_GF2m_simple_group_get_degree(const EC_GROUP *);
 465 int ec_GF2m_simple_group_check_discriminant(const EC_GROUP *, BN_CTX *);
 466 int ec_GF2m_simple_point_init(EC_POINT *);
 467 void ec_GF2m_simple_point_finish(EC_POINT *);
 468 void ec_GF2m_simple_point_clear_finish(EC_POINT *);
 469 int ec_GF2m_simple_point_copy(EC_POINT *, const EC_POINT *);
 470 int ec_GF2m_simple_point_set_to_infinity(const EC_GROUP *, EC_POINT *);
 471 int ec_GF2m_simple_point_set_affine_coordinates(const EC_GROUP *, EC_POINT *,
 472                                                 const BIGNUM *x,
 473                                                 const BIGNUM *y, BN_CTX *);
 474 int ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *,
 475                                                 const EC_POINT *, BIGNUM *x,
 476                                                 BIGNUM *y, BN_CTX *);
 477 int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *, EC_POINT *,
 478                                               const BIGNUM *x, int y_bit,
 479                                               BN_CTX *);
 480 size_t ec_GF2m_simple_point2oct(const EC_GROUP *, const EC_POINT *,
 481                                 point_conversion_form_t form,
 482                                 unsigned char *buf, size_t len, BN_CTX *);
 483 int ec_GF2m_simple_oct2point(const EC_GROUP *, EC_POINT *,
 484                              const unsigned char *buf, size_t len, BN_CTX *);
 485 int ec_GF2m_simple_add(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
 486                        const EC_POINT *b, BN_CTX *);
 487 int ec_GF2m_simple_dbl(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
 488                        BN_CTX *);
 489 int ec_GF2m_simple_invert(const EC_GROUP *, EC_POINT *, BN_CTX *);
 490 int ec_GF2m_simple_is_at_infinity(const EC_GROUP *, const EC_POINT *);
 491 int ec_GF2m_simple_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
 492 int ec_GF2m_simple_cmp(const EC_GROUP *, const EC_POINT *a, const EC_POINT *b,
 493                        BN_CTX *);
 494 int ec_GF2m_simple_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
 495 int ec_GF2m_simple_points_make_affine(const EC_GROUP *, size_t num,
 496                                       EC_POINT *[], BN_CTX *);
 497 int ec_GF2m_simple_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 498                              const BIGNUM *b, BN_CTX *);
 499 int ec_GF2m_simple_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 500                              BN_CTX *);
 501 int ec_GF2m_simple_field_div(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
 502                              const BIGNUM *b, BN_CTX *);
 503
 504 #ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
 505 /* method functions in ecp_nistp224.c */
 506 int ec_GFp_nistp224_group_init(EC_GROUP *group);
 507 int ec_GFp_nistp224_group_set_curve(EC_GROUP *group, const BIGNUM *p,
 508                                     const BIGNUM *a, const BIGNUM *n,
 509                                     BN_CTX *);
 510 int ec_GFp_nistp224_point_get_affine_coordinates(const EC_GROUP *group,
 511                                                  const EC_POINT *point,
 512                                                  BIGNUM *x, BIGNUM *y,
 513                                                  BN_CTX *ctx);
 514 int ec_GFp_nistp224_mul(const EC_GROUP *group, EC_POINT *r,
 515                         const BIGNUM *scalar, size_t num,
 516                         const EC_POINT *points[], const BIGNUM *scalars[],
 517                         BN_CTX *);
 518 int ec_GFp_nistp224_points_mul(const EC_GROUP *group, EC_POINT *r,
 519                                const BIGNUM *scalar, size_t num,
 520                                const EC_POINT *points[],
 521                                const BIGNUM *scalars[], BN_CTX *ctx);
 522 int ec_GFp_nistp224_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
 523 int ec_GFp_nistp224_have_precompute_mult(const EC_GROUP *group);
 524
 525 /* method functions in ecp_nistp256.c */
 526 int ec_GFp_nistp256_group_init(EC_GROUP *group);
 527 int ec_GFp_nistp256_group_set_curve(EC_GROUP *group, const BIGNUM *p,
 528                                     const BIGNUM *a, const BIGNUM *n,
 529                                     BN_CTX *);
 530 int ec_GFp_nistp256_point_get_affine_coordinates(const EC_GROUP *group,
 531                                                  const EC_POINT *point,
 532                                                  BIGNUM *x, BIGNUM *y,
 533                                                  BN_CTX *ctx);
 534 int ec_GFp_nistp256_mul(const EC_GROUP *group, EC_POINT *r,
 535                         const BIGNUM *scalar, size_t num,
 536                         const EC_POINT *points[], const BIGNUM *scalars[],
 537                         BN_CTX *);
 538 int ec_GFp_nistp256_points_mul(const EC_GROUP *group, EC_POINT *r,
 539                                const BIGNUM *scalar, size_t num,
 540                                const EC_POINT *points[],
 541                                const BIGNUM *scalars[], BN_CTX *ctx);
 542 int ec_GFp_nistp256_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
 543 int ec_GFp_nistp256_have_precompute_mult(const EC_GROUP *group);
 544
 545 /* method functions in ecp_nistp521.c */
 546 int ec_GFp_nistp521_group_init(EC_GROUP *group);
 547 int ec_GFp_nistp521_group_set_curve(EC_GROUP *group, const BIGNUM *p,
 548                                     const BIGNUM *a, const BIGNUM *n,
 549                                     BN_CTX *);
 550 int ec_GFp_nistp521_point_get_affine_coordinates(const EC_GROUP *group,
 551                                                  const EC_POINT *point,
 552                                                  BIGNUM *x, BIGNUM *y,
 553                                                  BN_CTX *ctx);
 554 int ec_GFp_nistp521_mul(const EC_GROUP *group, EC_POINT *r,
 555                         const BIGNUM *scalar, size_t num,
 556                         const EC_POINT *points[], const BIGNUM *scalars[],
 557                         BN_CTX *);
 558 int ec_GFp_nistp521_points_mul(const EC_GROUP *group, EC_POINT *r,
 559                                const BIGNUM *scalar, size_t num,
 560                                const EC_POINT *points[],
 561                                const BIGNUM *scalars[], BN_CTX *ctx);
 562 int ec_GFp_nistp521_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
 563 int ec_GFp_nistp521_have_precompute_mult(const EC_GROUP *group);
 564
 565 /* utility functions in ecp_nistputil.c */
 566 void ec_GFp_nistp_points_make_affine_internal(size_t num, void *point_array,
 567                                               size_t felem_size,
 568                                               void *tmp_felems,
 569                                               void (*felem_one) (void *out),
 570                                               int (*felem_is_zero) (const void
 571                                                                     *in),
 572                                               void (*felem_assign) (void *out,
 573                                                                     const void
 574                                                                     *in),
 575                                               void (*felem_square) (void *out,
 576                                                                     const void
 577                                                                     *in),
 578                                               void (*felem_mul) (void *out,
 579                                                                  const void
 580                                                                  *in1,
 581                                                                  const void
 582                                                                  *in2),
 583                                               void (*felem_inv) (void *out,
 584                                                                  const void
 585                                                                  *in),
 586                                               void (*felem_contract) (void
 587                                                                       *out,
 588                                                                       const
 589                                                                       void
 590                                                                       *in));
 591 void ec_GFp_nistp_recode_scalar_bits(unsigned char *sign,
 592                                      unsigned char *digit, unsigned char in);
 593 #endif
 594 int ec_group_simple_order_bits(const EC_GROUP *group);
 595
 596 /**
 597  *  Creates a new EC_GROUP object
 598  *  \param   libctx The associated library context or NULL for the default
 599  *                  library context
 600  *  \param   propq  Any property query string
 601  *  \param   meth   EC_METHOD to use
 602  *  \return  newly created EC_GROUP object or NULL in case of an error.
 603  */
 604 EC_GROUP *ec_group_new_ex(OSSL_LIB_CTX *libctx, const char *propq,
 605                           const EC_METHOD *meth);
 606
 607 #ifdef ECP_NISTZ256_ASM
 608 /** Returns GFp methods using montgomery multiplication, with x86-64 optimized
 609  * P256. See http://eprint.iacr.org/2013/816.
 610  *  \return  EC_METHOD object
 611  */
 612 const EC_METHOD *EC_GFp_nistz256_method(void);
 613 #endif
 614 #ifdef S390X_EC_ASM
 615 const EC_METHOD *EC_GFp_s390x_nistp256_method(void);
 616 const EC_METHOD *EC_GFp_s390x_nistp384_method(void);
 617 const EC_METHOD *EC_GFp_s390x_nistp521_method(void);
 618 #endif
 619
 620 size_t ec_key_simple_priv2oct(const EC_KEY *eckey,
 621                               unsigned char *buf, size_t len);
 622 int ec_key_simple_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len);
 623 int ec_key_simple_generate_key(EC_KEY *eckey);
 624 int ec_key_simple_generate_public_key(EC_KEY *eckey);
 625 int ec_key_simple_check_key(const EC_KEY *eckey);
 626
 627 int ec_curve_nid_from_params(const EC_GROUP *group, BN_CTX *ctx);
 628
 629 /* EC_METHOD definitions */
 630
 631 struct ec_key_method_st {
 632     const char *name;
 633     int32_t flags;
 634     int (*init)(EC_KEY *key);
 635     void (*finish)(EC_KEY *key);
 636     int (*copy)(EC_KEY *dest, const EC_KEY *src);
 637     int (*set_group)(EC_KEY *key, const EC_GROUP *grp);
 638     int (*set_private)(EC_KEY *key, const BIGNUM *priv_key);
 639     int (*set_public)(EC_KEY *key, const EC_POINT *pub_key);
 640     int (*keygen)(EC_KEY *key);
 641     int (*compute_key)(unsigned char **pout, size_t *poutlen,
 642                        const EC_POINT *pub_key, const EC_KEY *ecdh);
 643     int (*sign)(int type, const unsigned char *dgst, int dlen, unsigned char
 644                 *sig, unsigned int *siglen, const BIGNUM *kinv,
 645                 const BIGNUM *r, EC_KEY *eckey);
 646     int (*sign_setup)(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
 647                       BIGNUM **rp);
 648     ECDSA_SIG *(*sign_sig)(const unsigned char *dgst, int dgst_len,
 649                            const BIGNUM *in_kinv, const BIGNUM *in_r,
 650                            EC_KEY *eckey);
 651
 652     int (*verify)(int type, const unsigned char *dgst, int dgst_len,
 653                   const unsigned char *sigbuf, int sig_len, EC_KEY *eckey);
 654     int (*verify_sig)(const unsigned char *dgst, int dgst_len,
 655                       const ECDSA_SIG *sig, EC_KEY *eckey);
 656 };
 657
 658 #define EC_KEY_METHOD_DYNAMIC   1
 659
 660 EC_KEY *ec_key_new_method_int(OSSL_LIB_CTX *libctx, const char *propq,
 661                               ENGINE *engine);
 662
 663 int ossl_ec_key_gen(EC_KEY *eckey);
 664 int ossl_ecdh_compute_key(unsigned char **pout, size_t *poutlen,
 665                           const EC_POINT *pub_key, const EC_KEY *ecdh);
 666 int ecdh_simple_compute_key(unsigned char **pout, size_t *poutlen,
 667                             const EC_POINT *pub_key, const EC_KEY *ecdh);
 668
 669 struct ECDSA_SIG_st {
 670     BIGNUM *r;
 671     BIGNUM *s;
 672 };
 673
 674 int ossl_ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
 675                           BIGNUM **rp);
 676 int ossl_ecdsa_sign(int type, const unsigned char *dgst, int dlen,
 677                     unsigned char *sig, unsigned int *siglen,
 678                     const BIGNUM *kinv, const BIGNUM *r, EC_KEY *eckey);
 679 ECDSA_SIG *ossl_ecdsa_sign_sig(const unsigned char *dgst, int dgst_len,
 680                                const BIGNUM *in_kinv, const BIGNUM *in_r,
 681                                EC_KEY *eckey);
 682 int ossl_ecdsa_verify(int type, const unsigned char *dgst, int dgst_len,
 683                       const unsigned char *sigbuf, int sig_len, EC_KEY *eckey);
 684 int ossl_ecdsa_verify_sig(const unsigned char *dgst, int dgst_len,
 685                           const ECDSA_SIG *sig, EC_KEY *eckey);
 686 int ecdsa_simple_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
 687                             BIGNUM **rp);
 688 ECDSA_SIG *ecdsa_simple_sign_sig(const unsigned char *dgst, int dgst_len,
 689                                  const BIGNUM *in_kinv, const BIGNUM *in_r,
 690                                  EC_KEY *eckey);
 691 int ecdsa_simple_verify_sig(const unsigned char *dgst, int dgst_len,
 692                             const ECDSA_SIG *sig, EC_KEY *eckey);
 693
 694
 695 /*-
 696  * This functions computes a single point multiplication over the EC group,
 697  * using, at a high level, a Montgomery ladder with conditional swaps, with
 698  * various timing attack defenses.
 699  *
 700  * It performs either a fixed point multiplication
 701  *          (scalar * generator)
 702  * when point is NULL, or a variable point multiplication
 703  *          (scalar * point)
 704  * when point is not NULL.
 705  *
 706  * `scalar` cannot be NULL and should be in the range [0,n) otherwise all
 707  * constant time bets are off (where n is the cardinality of the EC group).
 708  *
 709  * This function expects `group->order` and `group->cardinality` to be well
 710  * defined and non-zero: it fails with an error code otherwise.
 711  *
 712  * NB: This says nothing about the constant-timeness of the ladder step
 713  * implementation (i.e., the default implementation is based on EC_POINT_add and
 714  * EC_POINT_dbl, which of course are not constant time themselves) or the
 715  * underlying multiprecision arithmetic.
 716  *
 717  * The product is stored in `r`.
 718  *
 719  * This is an internal function: callers are in charge of ensuring that the
 720  * input parameters `group`, `r`, `scalar` and `ctx` are not NULL.
 721  *
 722  * Returns 1 on success, 0 otherwise.
 723  */
 724 int ec_scalar_mul_ladder(const EC_GROUP *group, EC_POINT *r,
 725                          const BIGNUM *scalar, const EC_POINT *point,
 726                          BN_CTX *ctx);
 727
 728 int ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx);
 729
 730 static ossl_inline int ec_point_ladder_pre(const EC_GROUP *group,
 731                                            EC_POINT *r, EC_POINT *s,
 732                                            EC_POINT *p, BN_CTX *ctx)
 733 {
 734     if (group->meth->ladder_pre != NULL)
 735         return group->meth->ladder_pre(group, r, s, p, ctx);
 736
 737     if (!EC_POINT_copy(s, p)
 738         || !EC_POINT_dbl(group, r, s, ctx))
 739         return 0;
 740
 741     return 1;
 742 }
 743
 744 static ossl_inline int ec_point_ladder_step(const EC_GROUP *group,
 745                                             EC_POINT *r, EC_POINT *s,
 746                                             EC_POINT *p, BN_CTX *ctx)
 747 {
 748     if (group->meth->ladder_step != NULL)
 749         return group->meth->ladder_step(group, r, s, p, ctx);
 750
 751     if (!EC_POINT_add(group, s, r, s, ctx)
 752         || !EC_POINT_dbl(group, r, r, ctx))
 753         return 0;
 754
 755     return 1;
 756
 757 }
 758
 759 static ossl_inline int ec_point_ladder_post(const EC_GROUP *group,
 760                                             EC_POINT *r, EC_POINT *s,
 761                                             EC_POINT *p, BN_CTX *ctx)
 762 {
 763     if (group->meth->ladder_post != NULL)
 764         return group->meth->ladder_post(group, r, s, p, ctx);
 765
 766     return 1;
 767 }