crypto/ec/ec_local.h

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