boringssl/crypto/ec/internal.h
David Benjamin 2f6410ba4e Rewrite ECPrivateKey serialization.
Functions which lose object reuse and need auditing:
- d2i_ECParameters
- d2i_ECPrivateKey

This adds a handful of bytestring-based APIs to handle EC key
serialization. Deprecate all the old serialization APIs. Notes:

- An EC_KEY has additional state that controls its encoding, enc_flags
  and conv_form. conv_form is left alone, but enc_flags in the new API
  is an explicit parameter.

- d2i_ECPrivateKey interpreted its T** argument unlike nearly every
  other d2i function. This is an explicit EC_GROUP parameter in the new
  function.

- The new specified curve code is much stricter and should parse enough
  to uniquely identify the curve.

- I've not bothered with a new version of i2d_ECParameters. It just
  writes an OID. This may change later when decoupling from the giant
  OID table.

- Likewise, I've not bothered with new APIs for the public key since the
  EC_POINT APIs should suffice.

- Previously, d2i_ECPrivateKey would not call EC_KEY_check_key and it
  was possible for the imported public and private key to mismatch. It
  now calls it.

BUG=499653

Change-Id: I30b4dd2841ae76c56ab0e1808360b2628dee0615
Reviewed-on: https://boringssl-review.googlesource.com/6859
Reviewed-by: Adam Langley <agl@google.com>
2016-02-16 23:51:09 +00:00

302 lines
13 KiB
C

/* 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.
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* 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>
#if defined(__cplusplus)
extern "C" {
#endif
struct ec_method_st {
int (*group_init)(EC_GROUP *);
void (*group_finish)(EC_GROUP *);
int (*group_copy)(EC_GROUP *, const EC_GROUP *);
int (*group_set_curve)(EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
const BIGNUM *b, BN_CTX *);
int (*point_get_affine_coordinates)(const EC_GROUP *, const EC_POINT *,
BIGNUM *x, BIGNUM *y, BN_CTX *);
/* 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. */
int (*mul)(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,
const EC_POINT *p, const BIGNUM *p_scalar, BN_CTX *ctx);
/* |check_pub_key_order| checks that the public key is in the proper subgroup
* by checking that |pub_key*group->order| is the point at infinity. This may
* be NULL for |EC_METHOD|s specialized for prime-order curves (i.e. with
* cofactor one), as this check is not necessary for such curves (See section
* A.3 of the NSA's "Suite B Implementer's Guide to FIPS 186-3
* (ECDSA)"). */
int (*check_pub_key_order)(const EC_GROUP *group, const EC_POINT *pub_key,
BN_CTX *ctx);
/* 'field_mul' and 'field_sqr' can be used by 'add' and 'dbl' so that the
* same implementations of point operations can be used with different
* optimized implementations of expensive field operations: */
int (*field_mul)(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
const BIGNUM *b, BN_CTX *);
int (*field_sqr)(const EC_GROUP *, BIGNUM *r, const BIGNUM *a, BN_CTX *);
int (*field_encode)(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
BN_CTX *); /* e.g. to Montgomery */
int (*field_decode)(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
BN_CTX *); /* e.g. from Montgomery */
int (*field_set_to_one)(const EC_GROUP *, BIGNUM *r, BN_CTX *);
} /* EC_METHOD */;
const EC_METHOD* EC_GFp_mont_method(void);
struct ec_group_st {
const EC_METHOD *meth;
EC_POINT *generator;
BIGNUM order, cofactor;
int curve_name; /* optional NID for named curve */
const BN_MONT_CTX *mont_data; /* 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. */
BIGNUM a, b; /* Curve coefficients. */
int a_is_minus3; /* enable optimized point arithmetics for special case */
BN_MONT_CTX *mont; /* Montgomery structure. */
BIGNUM *one; /* The value one */
} /* EC_GROUP */;
struct ec_point_st {
const EC_METHOD *meth;
BIGNUM X;
BIGNUM Y;
BIGNUM Z; /* Jacobian projective coordinates:
* (X, Y, Z) represents (X/Z^2, Y/Z^3) if Z != 0 */
int Z_is_one; /* enable optimized point arithmetics for special case */
} /* EC_POINT */;
EC_GROUP *ec_group_new(const EC_METHOD *meth);
int ec_group_copy(EC_GROUP *dest, const EC_GROUP *src);
/* ec_group_get_mont_data returns a Montgomery context for operations in the
* scalar field of |group|. It may return NULL in the case that |group| is not
* a built-in group. */
const BN_MONT_CTX *ec_group_get_mont_data(const EC_GROUP *group);
int ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,
const EC_POINT *p, const BIGNUM *p_scalar, BN_CTX *ctx);
/* 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_copy(EC_GROUP *, const 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, BN_CTX *);
unsigned ec_GFp_simple_group_get_degree(const EC_GROUP *);
int ec_GFp_simple_point_init(EC_POINT *);
void ec_GFp_simple_point_finish(EC_POINT *);
void ec_GFp_simple_point_clear_finish(EC_POINT *);
int ec_GFp_simple_point_copy(EC_POINT *, const EC_POINT *);
int ec_GFp_simple_point_set_to_infinity(const EC_GROUP *, EC_POINT *);
int ec_GFp_simple_set_Jprojective_coordinates_GFp(const EC_GROUP *, EC_POINT *,
const BIGNUM *x,
const BIGNUM *y,
const BIGNUM *z, BN_CTX *);
int ec_GFp_simple_get_Jprojective_coordinates_GFp(const EC_GROUP *,
const EC_POINT *, BIGNUM *x,
BIGNUM *y, BIGNUM *z,
BN_CTX *);
int ec_GFp_simple_point_set_affine_coordinates(const EC_GROUP *, EC_POINT *,
const BIGNUM *x, const BIGNUM *y,
BN_CTX *);
int ec_GFp_simple_point_get_affine_coordinates(const EC_GROUP *,
const EC_POINT *, BIGNUM *x,
BIGNUM *y, BN_CTX *);
int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *, EC_POINT *,
const BIGNUM *x, int y_bit,
BN_CTX *);
int ec_GFp_simple_add(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
const EC_POINT *b, BN_CTX *);
int ec_GFp_simple_dbl(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
BN_CTX *);
int ec_GFp_simple_invert(const EC_GROUP *, EC_POINT *, BN_CTX *);
int ec_GFp_simple_is_at_infinity(const EC_GROUP *, const EC_POINT *);
int ec_GFp_simple_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
int ec_GFp_simple_cmp(const EC_GROUP *, const EC_POINT *a, const EC_POINT *b,
BN_CTX *);
int ec_GFp_simple_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
int ec_GFp_simple_points_make_affine(const EC_GROUP *, size_t num,
EC_POINT * [], BN_CTX *);
int ec_GFp_simple_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
const BIGNUM *b, BN_CTX *);
int ec_GFp_simple_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
BN_CTX *);
/* 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 *);
int ec_GFp_mont_group_copy(EC_GROUP *, const EC_GROUP *);
int ec_GFp_mont_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
const BIGNUM *b, BN_CTX *);
int ec_GFp_mont_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
BN_CTX *);
int ec_GFp_mont_field_encode(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
BN_CTX *);
int ec_GFp_mont_field_decode(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
BN_CTX *);
int ec_GFp_mont_field_set_to_one(const EC_GROUP *, BIGNUM *r, BN_CTX *);
int ec_point_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
EC_POINT *point, const BIGNUM *x,
const BIGNUM *y, const BIGNUM *z,
BN_CTX *ctx);
void ec_GFp_nistp_points_make_affine_internal(
size_t num, void *point_array, size_t felem_size, void *tmp_felems,
void (*felem_one)(void *out), int (*felem_is_zero)(const void *in),
void (*felem_assign)(void *out, const void *in),
void (*felem_square)(void *out, const void *in),
void (*felem_mul)(void *out, const void *in1, const void *in2),
void (*felem_inv)(void *out, const void *in),
void (*felem_contract)(void *out, const void *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);
/* Returns GFp methods using montgomery multiplication, with x86-64
* optimized P256. See http://eprint.iacr.org/2013/816. */
const EC_METHOD *EC_GFp_nistz256_method(void);
struct ec_key_st {
EC_GROUP *group;
EC_POINT *pub_key;
BIGNUM *priv_key;
unsigned int enc_flag;
point_conversion_form_t conv_form;
CRYPTO_refcount_t references;
int flags;
ECDSA_METHOD *ecdsa_meth;
CRYPTO_EX_DATA ex_data;
} /* EC_KEY */;
/* curve_data contains data about a built-in elliptic curve. */
struct curve_data {
/* 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;
/* cofactor is the cofactor of the group (i.e. the number of elements in the
* group divided by the size of the main subgroup. */
uint8_t cofactor; /* promoted to BN_ULONG */
/* data 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 data[];
};
struct built_in_curve {
int nid;
const struct curve_data *data;
const EC_METHOD *(*method)(void);
};
/* OPENSSL_built_in_curves is terminated with an entry where |nid| is
* |NID_undef|. */
extern const struct built_in_curve OPENSSL_built_in_curves[];
#if defined(__cplusplus)
} /* extern C */
#endif
#endif /* OPENSSL_HEADER_EC_INTERNAL_H */