/* Originally written by Bodo Moeller for the OpenSSL project. * ==================================================================== * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * openssl-core@openssl.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.openssl.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ /* ==================================================================== * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. * * Portions of the attached software ("Contribution") are developed by * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project. * * The Contribution is licensed pursuant to the OpenSSL open source * license provided above. * * The elliptic curve binary polynomial software is originally written by * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems * Laboratories. */ #ifndef OPENSSL_HEADER_EC_INTERNAL_H #define OPENSSL_HEADER_EC_INTERNAL_H #include <openssl/base.h> #include <openssl/bn.h> #include <openssl/ex_data.h> #include <openssl/thread.h> #include <openssl/type_check.h> #include "../bn/internal.h" #if defined(__cplusplus) extern "C" { #endif // Cap the size of all field elements and scalars, including custom curves, to // 66 bytes, large enough to fit secp521r1 and brainpoolP512r1, which appear to // be the largest fields anyone plausibly uses. #define EC_MAX_BYTES 66 #define EC_MAX_WORDS ((EC_MAX_BYTES + BN_BYTES - 1) / BN_BYTES) OPENSSL_STATIC_ASSERT(EC_MAX_WORDS <= BN_SMALL_MAX_WORDS, "bn_*_small functions not usable"); // An EC_SCALAR is an integer fully reduced modulo the order. Only the first // |order->width| words are used. An |EC_SCALAR| is specific to an |EC_GROUP| // and must not be mixed between groups. typedef union { // bytes is the representation of the scalar in little-endian order. uint8_t bytes[EC_MAX_BYTES]; BN_ULONG words[EC_MAX_WORDS]; } EC_SCALAR; // An EC_FELEM represents a field element. Only the first |field->width| words // are used. An |EC_FELEM| is specific to an |EC_GROUP| and must not be mixed // between groups. Additionally, the representation (whether or not elements are // represented in Montgomery-form) may vary between |EC_METHOD|s. typedef union { // bytes is the representation of the field element in little-endian order. uint8_t bytes[EC_MAX_BYTES]; BN_ULONG words[EC_MAX_WORDS]; } EC_FELEM; // An EC_RAW_POINT represents an elliptic curve point. Unlike |EC_POINT|, it is // a plain struct which can be stack-allocated and needs no cleanup. It is // specific to an |EC_GROUP| and must not be mixed between groups. typedef struct { EC_FELEM X, Y, Z; // X, Y, and Z are Jacobian projective coordinates. They represent // (X/Z^2, Y/Z^3) if Z != 0 and the point at infinity otherwise. } EC_RAW_POINT; struct ec_method_st { int (*group_init)(EC_GROUP *); void (*group_finish)(EC_GROUP *); int (*group_set_curve)(EC_GROUP *, const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *); // point_get_affine_coordinates sets |*x| and |*y| to the affine coordinates // of |p|. Either |x| or |y| may be NULL to omit it. It returns one on success // and zero if |p| is the point at infinity. // // Note: unlike |EC_FELEM|s used as intermediate values internal to the // |EC_METHOD|, |*x| and |*y| are not encoded in Montgomery form. int (*point_get_affine_coordinates)(const EC_GROUP *, const EC_RAW_POINT *p, EC_FELEM *x, EC_FELEM *y); // add sets |r| to |a| + |b|. void (*add)(const EC_GROUP *group, EC_RAW_POINT *r, const EC_RAW_POINT *a, const EC_RAW_POINT *b); // dbl sets |r| to |a| + |a|. void (*dbl)(const EC_GROUP *group, EC_RAW_POINT *r, const EC_RAW_POINT *a); // Computes |r = g_scalar*generator + p_scalar*p| if |g_scalar| and |p_scalar| // are both non-null. Computes |r = g_scalar*generator| if |p_scalar| is null. // Computes |r = p_scalar*p| if g_scalar is null. At least one of |g_scalar| // and |p_scalar| must be non-null, and |p| must be non-null if |p_scalar| is // non-null. void (*mul)(const EC_GROUP *group, EC_RAW_POINT *r, const EC_SCALAR *g_scalar, const EC_RAW_POINT *p, const EC_SCALAR *p_scalar); // mul_public performs the same computation as mul. It further assumes that // the inputs are public so there is no concern about leaking their values // through timing. void (*mul_public)(const EC_GROUP *group, EC_RAW_POINT *r, const EC_SCALAR *g_scalar, const EC_RAW_POINT *p, const EC_SCALAR *p_scalar); // felem_mul and felem_sqr implement multiplication and squaring, // respectively, so that the generic |EC_POINT_add| and |EC_POINT_dbl| // implementations can work both with |EC_GFp_mont_method| and the tuned // operations. // // TODO(davidben): This constrains |EC_FELEM|'s internal representation, adds // many indirect calls in the middle of the generic code, and a bunch of // conversions. If p224-64.c were easily convertable to Montgomery form, we // could say |EC_FELEM| is always in Montgomery form. If we routed the rest of // simple.c to |EC_METHOD|, we could give |EC_POINT| an |EC_METHOD|-specific // representation and say |EC_FELEM| is purely a |EC_GFp_mont_method| type. void (*felem_mul)(const EC_GROUP *, EC_FELEM *r, const EC_FELEM *a, const EC_FELEM *b); void (*felem_sqr)(const EC_GROUP *, EC_FELEM *r, const EC_FELEM *a); int (*bignum_to_felem)(const EC_GROUP *group, EC_FELEM *out, const BIGNUM *in); int (*felem_to_bignum)(const EC_GROUP *group, BIGNUM *out, const EC_FELEM *in); // scalar_inv_montgomery sets |out| to |in|^-1, where both input and output // are in Montgomery form. void (*scalar_inv_montgomery)(const EC_GROUP *group, EC_SCALAR *out, const EC_SCALAR *in); // scalar_inv_montgomery_vartime performs the same computation as // |scalar_inv_montgomery|. It further assumes that the inputs are public so // there is no concern about leaking their values through timing. int (*scalar_inv_montgomery_vartime)(const EC_GROUP *group, EC_SCALAR *out, const EC_SCALAR *in); // cmp_x_coordinate compares the x (affine) coordinate of |p|, mod the group // order, with |r|. It returns one if the values match and zero if |p| is the // point at infinity of the values do not match. int (*cmp_x_coordinate)(const EC_GROUP *group, const EC_RAW_POINT *p, const EC_SCALAR *r); } /* EC_METHOD */; const EC_METHOD *EC_GFp_mont_method(void); struct ec_group_st { const EC_METHOD *meth; // Unlike all other |EC_POINT|s, |generator| does not own |generator->group| // to avoid a reference cycle. EC_POINT *generator; BIGNUM order; int curve_name; // optional NID for named curve BN_MONT_CTX *order_mont; // data for ECDSA inverse // The following members are handled by the method functions, // even if they appear generic BIGNUM field; // For curves over GF(p), this is the modulus. EC_FELEM a, b; // Curve coefficients. // a_is_minus3 is one if |a| is -3 mod |field| and zero otherwise. Point // arithmetic is optimized for -3. int a_is_minus3; // field_greater_than_order is one if |field| is greate than |order| and zero // otherwise. int field_greater_than_order; // field_minus_order, if |field_greater_than_order| is true, is |field| minus // |order| represented as an |EC_FELEM|. Otherwise, it is zero. // // Note: unlike |EC_FELEM|s used as intermediate values internal to the // |EC_METHOD|, this value is not encoded in Montgomery form. EC_FELEM field_minus_order; CRYPTO_refcount_t references; BN_MONT_CTX *mont; // Montgomery structure. EC_FELEM one; // The value one. } /* EC_GROUP */; struct ec_point_st { // group is an owning reference to |group|, unless this is // |group->generator|. EC_GROUP *group; // raw is the group-specific point data. Functions that take |EC_POINT| // typically check consistency with |EC_GROUP| while functions that take // |EC_RAW_POINT| do not. Thus accesses to this field should be externally // checked for consistency. EC_RAW_POINT raw; } /* EC_POINT */; EC_GROUP *ec_group_new(const EC_METHOD *meth); // ec_bignum_to_felem converts |in| to an |EC_FELEM|. It returns one on success // and zero if |in| is out of range. int ec_bignum_to_felem(const EC_GROUP *group, EC_FELEM *out, const BIGNUM *in); // ec_felem_to_bignum converts |in| to a |BIGNUM|. It returns one on success and // zero on allocation failure. int ec_felem_to_bignum(const EC_GROUP *group, BIGNUM *out, const EC_FELEM *in); // ec_felem_neg sets |out| to -|a|. void ec_felem_neg(const EC_GROUP *group, EC_FELEM *out, const EC_FELEM *a); // ec_felem_add sets |out| to |a| + |b|. void ec_felem_add(const EC_GROUP *group, EC_FELEM *out, const EC_FELEM *a, const EC_FELEM *b); // ec_felem_add sets |out| to |a| - |b|. void ec_felem_sub(const EC_GROUP *group, EC_FELEM *out, const EC_FELEM *a, const EC_FELEM *b); // ec_felem_non_zero_mask returns all ones if |a| is non-zero and all zeros // otherwise. BN_ULONG ec_felem_non_zero_mask(const EC_GROUP *group, const EC_FELEM *a); // ec_felem_select, in constant time, sets |out| to |a| if |mask| is all ones // and |b| if |mask| is all zeros. void ec_felem_select(const EC_GROUP *group, EC_FELEM *out, BN_ULONG mask, const EC_FELEM *a, const EC_FELEM *b); // ec_felem_equal returns one if |a| and |b| are equal and zero otherwise. It // treats |a| and |b| as public and does *not* run in constant time. int ec_felem_equal(const EC_GROUP *group, const EC_FELEM *a, const EC_FELEM *b); // ec_bignum_to_scalar converts |in| to an |EC_SCALAR| and writes it to // |*out|. It returns one on success and zero if |in| is out of range. OPENSSL_EXPORT int ec_bignum_to_scalar(const EC_GROUP *group, EC_SCALAR *out, const BIGNUM *in); // ec_random_nonzero_scalar sets |out| to a uniformly selected random value from // 1 to |group->order| - 1. It returns one on success and zero on error. int ec_random_nonzero_scalar(const EC_GROUP *group, EC_SCALAR *out, const uint8_t additional_data[32]); // ec_scalar_equal_vartime returns one if |a| and |b| are equal and zero // otherwise. Both values are treated as public. int ec_scalar_equal_vartime(const EC_GROUP *group, const EC_SCALAR *a, const EC_SCALAR *b); // ec_scalar_is_zero returns one if |a| is zero and zero otherwise. int ec_scalar_is_zero(const EC_GROUP *group, const EC_SCALAR *a); // ec_scalar_add sets |r| to |a| + |b|. void ec_scalar_add(const EC_GROUP *group, EC_SCALAR *r, const EC_SCALAR *a, const EC_SCALAR *b); // ec_scalar_to_montgomery sets |r| to |a| in Montgomery form. void ec_scalar_to_montgomery(const EC_GROUP *group, EC_SCALAR *r, const EC_SCALAR *a); // ec_scalar_to_montgomery sets |r| to |a| converted from Montgomery form. void ec_scalar_from_montgomery(const EC_GROUP *group, EC_SCALAR *r, const EC_SCALAR *a); // ec_scalar_mul_montgomery sets |r| to |a| * |b| where inputs and outputs are // in Montgomery form. void ec_scalar_mul_montgomery(const EC_GROUP *group, EC_SCALAR *r, const EC_SCALAR *a, const EC_SCALAR *b); // ec_scalar_mul_montgomery sets |r| to |a|^-1 where inputs and outputs are in // Montgomery form. void ec_scalar_inv_montgomery(const EC_GROUP *group, EC_SCALAR *r, const EC_SCALAR *a); // ec_scalar_inv_montgomery_vartime performs the same actions as // |ec_scalar_inv_montgomery|, but in variable time. int ec_scalar_inv_montgomery_vartime(const EC_GROUP *group, EC_SCALAR *r, const EC_SCALAR *a); // ec_point_mul_scalar sets |r| to generator * |g_scalar| + |p| * // |p_scalar|. Unlike other functions which take |EC_SCALAR|, |g_scalar| and // |p_scalar| need not be fully reduced. They need only contain as many bits as // the order. int ec_point_mul_scalar(const EC_GROUP *group, EC_RAW_POINT *r, const EC_SCALAR *g_scalar, const EC_RAW_POINT *p, const EC_SCALAR *p_scalar); // ec_point_mul_scalar_public performs the same computation as // ec_point_mul_scalar. It further assumes that the inputs are public so // there is no concern about leaking their values through timing. OPENSSL_EXPORT int ec_point_mul_scalar_public(const EC_GROUP *group, EC_RAW_POINT *r, const EC_SCALAR *g_scalar, const EC_RAW_POINT *p, const EC_SCALAR *p_scalar); // ec_cmp_x_coordinate compares the x (affine) coordinate of |p|, mod the group // order, with |r|. It returns one if the values match and zero if |p| is the // point at infinity of the values do not match. int ec_cmp_x_coordinate(const EC_GROUP *group, const EC_RAW_POINT *p, const EC_SCALAR *r); // ec_get_x_coordinate_as_scalar sets |*out| to |p|'s x-coordinate, modulo // |group->order|. It returns one on success and zero if |p| is the point at // infinity. int ec_get_x_coordinate_as_scalar(const EC_GROUP *group, EC_SCALAR *out, const EC_RAW_POINT *p); // ec_point_get_affine_coordinate_bytes writes |p|'s affine coordinates to // |out_x| and |out_y|, each of which must have at must |max_out| bytes. It sets // |*out_len| to the number of bytes written in each buffer. Coordinates are // written big-endian and zero-padded to the size of the field. // // Either of |out_x| or |out_y| may be NULL to omit that coordinate. This // function returns one on success and zero on failure. int ec_point_get_affine_coordinate_bytes(const EC_GROUP *group, uint8_t *out_x, uint8_t *out_y, size_t *out_len, size_t max_out, const EC_RAW_POINT *p); // ec_field_element_to_scalar reduces |r| modulo |group->order|. |r| must // previously have been reduced modulo |group->field|. int ec_field_element_to_scalar(const EC_GROUP *group, BIGNUM *r); void ec_GFp_mont_mul(const EC_GROUP *group, EC_RAW_POINT *r, const EC_SCALAR *g_scalar, const EC_RAW_POINT *p, const EC_SCALAR *p_scalar); // ec_compute_wNAF writes the modified width-(w+1) Non-Adjacent Form (wNAF) of // |scalar| to |out|. |out| must have room for |bits| + 1 elements, each of // which will be either zero or odd with an absolute value less than 2^w // satisfying // scalar = \sum_j out[j]*2^j // where at most one of any w+1 consecutive digits is non-zero // with the exception that the most significant digit may be only // w-1 zeros away from that next non-zero digit. void ec_compute_wNAF(const EC_GROUP *group, int8_t *out, const EC_SCALAR *scalar, size_t bits, int w); void ec_GFp_mont_mul_public(const EC_GROUP *group, EC_RAW_POINT *r, const EC_SCALAR *g_scalar, const EC_RAW_POINT *p, const EC_SCALAR *p_scalar); // method functions in simple.c int ec_GFp_simple_group_init(EC_GROUP *); void ec_GFp_simple_group_finish(EC_GROUP *); int ec_GFp_simple_group_set_curve(EC_GROUP *, const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *); int ec_GFp_simple_group_get_curve(const EC_GROUP *, BIGNUM *p, BIGNUM *a, BIGNUM *b); void ec_GFp_simple_point_init(EC_RAW_POINT *); void ec_GFp_simple_point_copy(EC_RAW_POINT *, const EC_RAW_POINT *); void ec_GFp_simple_point_set_to_infinity(const EC_GROUP *, EC_RAW_POINT *); int ec_GFp_simple_point_set_affine_coordinates(const EC_GROUP *, EC_RAW_POINT *, const BIGNUM *x, const BIGNUM *y); void ec_GFp_mont_add(const EC_GROUP *, EC_RAW_POINT *r, const EC_RAW_POINT *a, const EC_RAW_POINT *b); void ec_GFp_mont_dbl(const EC_GROUP *, EC_RAW_POINT *r, const EC_RAW_POINT *a); void ec_GFp_simple_invert(const EC_GROUP *, EC_RAW_POINT *); int ec_GFp_simple_is_at_infinity(const EC_GROUP *, const EC_RAW_POINT *); int ec_GFp_simple_is_on_curve(const EC_GROUP *, const EC_RAW_POINT *); int ec_GFp_simple_cmp(const EC_GROUP *, const EC_RAW_POINT *a, const EC_RAW_POINT *b); void ec_simple_scalar_inv_montgomery(const EC_GROUP *group, EC_SCALAR *r, const EC_SCALAR *a); int ec_GFp_simple_mont_inv_mod_ord_vartime(const EC_GROUP *group, EC_SCALAR *r, const EC_SCALAR *a); int ec_GFp_simple_cmp_x_coordinate(const EC_GROUP *group, const EC_RAW_POINT *p, const EC_SCALAR *r); // method functions in montgomery.c int ec_GFp_mont_group_init(EC_GROUP *); int ec_GFp_mont_group_set_curve(EC_GROUP *, const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *); void ec_GFp_mont_group_finish(EC_GROUP *); void ec_GFp_mont_felem_mul(const EC_GROUP *, EC_FELEM *r, const EC_FELEM *a, const EC_FELEM *b); void ec_GFp_mont_felem_sqr(const EC_GROUP *, EC_FELEM *r, const EC_FELEM *a); int ec_GFp_mont_bignum_to_felem(const EC_GROUP *group, EC_FELEM *out, const BIGNUM *in); int ec_GFp_mont_felem_to_bignum(const EC_GROUP *group, BIGNUM *out, const EC_FELEM *in); void ec_GFp_nistp_recode_scalar_bits(uint8_t *sign, uint8_t *digit, uint8_t in); const EC_METHOD *EC_GFp_nistp224_method(void); const EC_METHOD *EC_GFp_nistp256_method(void); // EC_GFp_nistz256_method is a GFp method using montgomery multiplication, with // x86-64 optimized P256. See http://eprint.iacr.org/2013/816. const EC_METHOD *EC_GFp_nistz256_method(void); // An EC_WRAPPED_SCALAR is an |EC_SCALAR| with a parallel |BIGNUM| // representation. It exists to support the |EC_KEY_get0_private_key| API. typedef struct { BIGNUM bignum; EC_SCALAR scalar; } EC_WRAPPED_SCALAR; struct ec_key_st { EC_GROUP *group; EC_POINT *pub_key; EC_WRAPPED_SCALAR *priv_key; // fixed_k may contain a specific value of 'k', to be used in ECDSA signing. // This is only for the FIPS power-on tests. BIGNUM *fixed_k; unsigned int enc_flag; point_conversion_form_t conv_form; CRYPTO_refcount_t references; ECDSA_METHOD *ecdsa_meth; CRYPTO_EX_DATA ex_data; } /* EC_KEY */; struct built_in_curve { int nid; const uint8_t *oid; uint8_t oid_len; // comment is a human-readable string describing the curve. const char *comment; // param_len is the number of bytes needed to store a field element. uint8_t param_len; // params points to an array of 6*|param_len| bytes which hold the field // elements of the following (in big-endian order): prime, a, b, generator x, // generator y, order. const uint8_t *params; const EC_METHOD *method; }; #define OPENSSL_NUM_BUILT_IN_CURVES 4 struct built_in_curves { struct built_in_curve curves[OPENSSL_NUM_BUILT_IN_CURVES]; }; // OPENSSL_built_in_curves returns a pointer to static information about // standard curves. The array is terminated with an entry where |nid| is // |NID_undef|. const struct built_in_curves *OPENSSL_built_in_curves(void); #if defined(__cplusplus) } // extern C #endif #endif // OPENSSL_HEADER_EC_INTERNAL_H