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openssl/crypto/ec/ec_lcl.h
Nicola Tuveri 9a43a73380 [ec] Match built-in curves on EC_GROUP_new_from_ecparameters 
Description
-----------

Upon `EC_GROUP_new_from_ecparameters()` check if the parameters match any
of the built-in curves. If that is the case, return a new
`EC_GROUP_new_by_curve_name()` object instead of the explicit parameters
`EC_GROUP`.

This affects all users of `EC_GROUP_new_from_ecparameters()`:
- direct calls to `EC_GROUP_new_from_ecparameters()`
- direct calls to `EC_GROUP_new_from_ecpkparameters()` with an explicit
  parameters argument
- ASN.1 parsing of explicit parameters keys (as it eventually
  ends up calling `EC_GROUP_new_from_ecpkparameters()`)

A parsed explicit parameter key will still be marked with the
`OPENSSL_EC_EXPLICIT_CURVE` ASN.1 flag on load, so, unless
programmatically forced otherwise, if the key is eventually serialized
the output will still be encoded with explicit parameters, even if
internally it is treated as a named curve `EC_GROUP`.

Before this change, creating any `EC_GROUP` object using
`EC_GROUP_new_from_ecparameters()`, yielded an object associated with
the default generic `EC_METHOD`, but this was never guaranteed in the
documentation.
After this commit, users of the library that intentionally want to
create an `EC_GROUP` object using a specific `EC_METHOD` can still
explicitly call `EC_GROUP_new(foo_method)` and then manually set the
curve parameters using `EC_GROUP_set_*()`.

Motivation
----------

This has obvious performance benefits for the built-in curves with
specialized `EC_METHOD`s and subtle but important security benefits:
- the specialized methods have better security hardening than the
  generic implementations
- optional fields in the parameter encoding, like the `cofactor`, cannot
  be leveraged by an attacker to force execution of the less secure
  code-paths for single point scalar multiplication
- in general, this leads to reducing the attack surface

Check the manuscript at https://arxiv.org/abs/1909.01785 for an in depth
analysis of the issues related to this commit.

It should be noted that `libssl` does not allow to negotiate explicit
parameters (as per RFC 8422), so it is not directly affected by the
consequences of using explicit parameters that this commit fixes.
On the other hand, we detected external applications and users in the
wild that use explicit parameters by default (and sometimes using 0 as
the cofactor value, which is technically not a valid value per the
specification, but is tolerated by parsers for wider compatibility given
that the field is optional).
These external users of `libcrypto` are exposed to these vulnerabilities
and their security will benefit from this commit.

Related commits
---------------

While this commit is beneficial for users using built-in curves and
explicit parameters encoding for serialized keys, commit
b783beeadf6b80bc431e6f3230b5d5585c87ef87 (and its equivalents for the
1.0.2, 1.1.0 and 1.1.1 stable branches) fixes the consequences of the
invalid cofactor values more in general also for other curves
(CVE-2019-1547).

The following list covers commits in `master` that are related to the
vulnerabilities presented in the manuscript motivating this commit:

- d2baf88c43 [crypto/rsa] Set the constant-time flag in multi-prime RSA too
- 311e903d84 [crypto/asn1] Fix multiple SCA vulnerabilities during RSA key validation.
- b783beeadf [crypto/ec] for ECC parameters with NULL or zero cofactor, compute it
- 724339ff44 Fix SCA vulnerability when using PVK and MSBLOB key formats

Note that the PRs that contributed the listed commits also include other
commits providing related testing and documentation, in addition to
links to PRs and commits backporting the fixes to the 1.0.2, 1.1.0 and
1.1.1 branches.

This commit includes a partial backport of
https://github.com/openssl/openssl/pull/8555
(commit 8402cd5f75)
for which the main author is Shane Lontis.

Responsible Disclosure
----------------------

This and the other issues presented in https://arxiv.org/abs/1909.01785
were reported by Cesar Pereida García, Sohaib ul Hassan, Nicola Tuveri,
Iaroslav Gridin, Alejandro Cabrera Aldaya and Billy Bob Brumley from the
NISEC group at Tampere University, FINLAND.

The OpenSSL Security Team evaluated the security risk for this
vulnerability as low, and encouraged to propose fixes using public Pull
Requests.

_______________________________________________________________________________

Co-authored-by: Shane Lontis <shane.lontis@oracle.com>

(Backport from https://github.com/openssl/openssl/pull/9808)

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9809)
2019-09-09 14:16:18 +03:00

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/*
* Copyright 2001-2019 The OpenSSL Project Authors. All Rights Reserved.
* Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdlib.h>
#include <openssl/obj_mac.h>
#include <openssl/ec.h>
#include <openssl/bn.h>
#include "internal/refcount.h"
#include "internal/ec_int.h"
#if defined(__SUNPRO_C)
# if __SUNPRO_C >= 0x520
# pragma error_messages (off,E_ARRAY_OF_INCOMPLETE_NONAME,E_ARRAY_OF_INCOMPLETE)
# endif
#endif
/* Use default functions for poin2oct, oct2point and compressed coordinates */
#define EC_FLAGS_DEFAULT_OCT 0x1
/* Use custom formats for EC_GROUP, EC_POINT and EC_KEY */
#define EC_FLAGS_CUSTOM_CURVE 0x2
/* Curve does not support signing operations */
#define EC_FLAGS_NO_SIGN 0x4
/*
* Structure details are not part of the exported interface, so all this may
* change in future versions.
*/
struct ec_method_st {
/* Various method flags */
int flags;
/* used by EC_METHOD_get_field_type: */
int field_type; /* a NID */
/*
* used by EC_GROUP_new, EC_GROUP_free, EC_GROUP_clear_free,
* EC_GROUP_copy:
*/
int (*group_init) (EC_GROUP *);
void (*group_finish) (EC_GROUP *);
void (*group_clear_finish) (EC_GROUP *);
int (*group_copy) (EC_GROUP *, const EC_GROUP *);
/* used by EC_GROUP_set_curve, EC_GROUP_get_curve: */
int (*group_set_curve) (EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
const BIGNUM *b, BN_CTX *);
int (*group_get_curve) (const EC_GROUP *, BIGNUM *p, BIGNUM *a, BIGNUM *b,
BN_CTX *);
/* used by EC_GROUP_get_degree: */
int (*group_get_degree) (const EC_GROUP *);
int (*group_order_bits) (const EC_GROUP *);
/* used by EC_GROUP_check: */
int (*group_check_discriminant) (const EC_GROUP *, BN_CTX *);
/*
* used by EC_POINT_new, EC_POINT_free, EC_POINT_clear_free,
* EC_POINT_copy:
*/
int (*point_init) (EC_POINT *);
void (*point_finish) (EC_POINT *);
void (*point_clear_finish) (EC_POINT *);
int (*point_copy) (EC_POINT *, const EC_POINT *);
/*-
* used by EC_POINT_set_to_infinity,
* EC_POINT_set_Jprojective_coordinates_GFp,
* EC_POINT_get_Jprojective_coordinates_GFp,
* EC_POINT_set_affine_coordinates,
* EC_POINT_get_affine_coordinates,
* EC_POINT_set_compressed_coordinates:
*/
int (*point_set_to_infinity) (const EC_GROUP *, EC_POINT *);
int (*point_set_Jprojective_coordinates_GFp) (const EC_GROUP *,
EC_POINT *, const BIGNUM *x,
const BIGNUM *y,
const BIGNUM *z, BN_CTX *);
int (*point_get_Jprojective_coordinates_GFp) (const EC_GROUP *,
const EC_POINT *, BIGNUM *x,
BIGNUM *y, BIGNUM *z,
BN_CTX *);
int (*point_set_affine_coordinates) (const EC_GROUP *, EC_POINT *,
const BIGNUM *x, const BIGNUM *y,
BN_CTX *);
int (*point_get_affine_coordinates) (const EC_GROUP *, const EC_POINT *,
BIGNUM *x, BIGNUM *y, BN_CTX *);
int (*point_set_compressed_coordinates) (const EC_GROUP *, EC_POINT *,
const BIGNUM *x, int y_bit,
BN_CTX *);
/* used by EC_POINT_point2oct, EC_POINT_oct2point: */
size_t (*point2oct) (const EC_GROUP *, const EC_POINT *,
point_conversion_form_t form, unsigned char *buf,
size_t len, BN_CTX *);
int (*oct2point) (const EC_GROUP *, EC_POINT *, const unsigned char *buf,
size_t len, BN_CTX *);
/* used by EC_POINT_add, EC_POINT_dbl, ECP_POINT_invert: */
int (*add) (const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
const EC_POINT *b, BN_CTX *);
int (*dbl) (const EC_GROUP *, EC_POINT *r, const EC_POINT *a, BN_CTX *);
int (*invert) (const EC_GROUP *, EC_POINT *, BN_CTX *);
/*
* used by EC_POINT_is_at_infinity, EC_POINT_is_on_curve, EC_POINT_cmp:
*/
int (*is_at_infinity) (const EC_GROUP *, const EC_POINT *);
int (*is_on_curve) (const EC_GROUP *, const EC_POINT *, BN_CTX *);
int (*point_cmp) (const EC_GROUP *, const EC_POINT *a, const EC_POINT *b,
BN_CTX *);
/* used by EC_POINT_make_affine, EC_POINTs_make_affine: */
int (*make_affine) (const EC_GROUP *, EC_POINT *, BN_CTX *);
int (*points_make_affine) (const EC_GROUP *, size_t num, EC_POINT *[],
BN_CTX *);
/*
* used by EC_POINTs_mul, EC_POINT_mul, EC_POINT_precompute_mult,
* EC_POINT_have_precompute_mult (default implementations are used if the
* 'mul' pointer is 0):
*/
/*-
* mul() calculates the value
*
* r := generator * scalar
* + points[0] * scalars[0]
* + ...
* + points[num-1] * scalars[num-1].
*
* For a fixed point multiplication (scalar != NULL, num == 0)
* or a variable point multiplication (scalar == NULL, num == 1),
* mul() must use a constant time algorithm: in both cases callers
* should provide an input scalar (either scalar or scalars[0])
* in the range [0, ec_group_order); for robustness, implementers
* should handle the case when the scalar has not been reduced, but
* may treat it as an unusual input, without any constant-timeness
* guarantee.
*/
int (*mul) (const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
size_t num, const EC_POINT *points[], const BIGNUM *scalars[],
BN_CTX *);
int (*precompute_mult) (EC_GROUP *group, BN_CTX *);
int (*have_precompute_mult) (const EC_GROUP *group);
/* internal functions */
/*
* 'field_mul', 'field_sqr', and 'field_div' 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_div) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
const BIGNUM *b, BN_CTX *);
/*-
* 'field_inv' computes the multiplicative inverse of a in the field,
* storing the result in r.
*
* If 'a' is zero (or equivalent), you'll get an EC_R_CANNOT_INVERT error.
*/
int (*field_inv) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a, BN_CTX *);
/* e.g. to Montgomery */
int (*field_encode) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
BN_CTX *);
/* e.g. from Montgomery */
int (*field_decode) (const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
BN_CTX *);
int (*field_set_to_one) (const EC_GROUP *, BIGNUM *r, BN_CTX *);
/* private key operations */
size_t (*priv2oct)(const EC_KEY *eckey, unsigned char *buf, size_t len);
int (*oct2priv)(EC_KEY *eckey, const unsigned char *buf, size_t len);
int (*set_private)(EC_KEY *eckey, const BIGNUM *priv_key);
int (*keygen)(EC_KEY *eckey);
int (*keycheck)(const EC_KEY *eckey);
int (*keygenpub)(EC_KEY *eckey);
int (*keycopy)(EC_KEY *dst, const EC_KEY *src);
void (*keyfinish)(EC_KEY *eckey);
/* custom ECDH operation */
int (*ecdh_compute_key)(unsigned char **pout, size_t *poutlen,
const EC_POINT *pub_key, const EC_KEY *ecdh);
/* Inverse modulo order */
int (*field_inverse_mod_ord)(const EC_GROUP *, BIGNUM *r,
const BIGNUM *x, BN_CTX *);
int (*blind_coordinates)(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx);
int (*ladder_pre)(const EC_GROUP *group,
EC_POINT *r, EC_POINT *s,
EC_POINT *p, BN_CTX *ctx);
int (*ladder_step)(const EC_GROUP *group,
EC_POINT *r, EC_POINT *s,
EC_POINT *p, BN_CTX *ctx);
int (*ladder_post)(const EC_GROUP *group,
EC_POINT *r, EC_POINT *s,
EC_POINT *p, BN_CTX *ctx);
};
/*
* Types and functions to manipulate pre-computed values.
*/
typedef struct nistp224_pre_comp_st NISTP224_PRE_COMP;
typedef struct nistp256_pre_comp_st NISTP256_PRE_COMP;
typedef struct nistp521_pre_comp_st NISTP521_PRE_COMP;
typedef struct nistz256_pre_comp_st NISTZ256_PRE_COMP;
typedef struct ec_pre_comp_st EC_PRE_COMP;
struct ec_group_st {
const EC_METHOD *meth;
EC_POINT *generator; /* optional */
BIGNUM *order, *cofactor;
int curve_name; /* optional NID for named curve */
int asn1_flag; /* flag to control the asn1 encoding */
point_conversion_form_t asn1_form;
unsigned char *seed; /* optional seed for parameters (appears in
* ASN1) */
size_t seed_len;
/*
* The following members are handled by the method functions, even if
* they appear generic
*/
/*
* Field specification. For curves over GF(p), this is the modulus; for
* curves over GF(2^m), this is the irreducible polynomial defining the
* field.
*/
BIGNUM *field;
/*
* Field specification for curves over GF(2^m). The irreducible f(t) is
* then of the form: t^poly[0] + t^poly[1] + ... + t^poly[k] where m =
* poly[0] > poly[1] > ... > poly[k] = 0. The array is terminated with
* poly[k+1]=-1. All elliptic curve irreducibles have at most 5 non-zero
* terms.
*/
int poly[6];
/*
* Curve coefficients. (Here the assumption is that BIGNUMs can be used
* or abused for all kinds of fields, not just GF(p).) For characteristic
* > 3, the curve is defined by a Weierstrass equation of the form y^2 =
* x^3 + a*x + b. For characteristic 2, the curve is defined by an
* equation of the form y^2 + x*y = x^3 + a*x^2 + b.
*/
BIGNUM *a, *b;
/* enable optimized point arithmetics for special case */
int a_is_minus3;
/* method-specific (e.g., Montgomery structure) */
void *field_data1;
/* method-specific */
void *field_data2;
/* method-specific */
int (*field_mod_func) (BIGNUM *, const BIGNUM *, const BIGNUM *,
BN_CTX *);
/* data for ECDSA inverse */
BN_MONT_CTX *mont_data;
/*
* Precomputed values for speed. The PCT_xxx names match the
* pre_comp.xxx union names; see the SETPRECOMP and HAVEPRECOMP
* macros, below.
*/
enum {
PCT_none,
PCT_nistp224, PCT_nistp256, PCT_nistp521, PCT_nistz256,
PCT_ec
} pre_comp_type;
union {
NISTP224_PRE_COMP *nistp224;
NISTP256_PRE_COMP *nistp256;
NISTP521_PRE_COMP *nistp521;
NISTZ256_PRE_COMP *nistz256;
EC_PRE_COMP *ec;
} pre_comp;
};
#define SETPRECOMP(g, type, pre) \
g->pre_comp_type = PCT_##type, g->pre_comp.type = pre
#define HAVEPRECOMP(g, type) \
g->pre_comp_type == PCT_##type && g->pre_comp.type != NULL
struct ec_key_st {
const EC_KEY_METHOD *meth;
ENGINE *engine;
int version;
EC_GROUP *group;
EC_POINT *pub_key;
BIGNUM *priv_key;
unsigned int enc_flag;
point_conversion_form_t conv_form;
CRYPTO_REF_COUNT references;
int flags;
CRYPTO_EX_DATA ex_data;
CRYPTO_RWLOCK *lock;
};
struct ec_point_st {
const EC_METHOD *meth;
/* NID for the curve if known */
int curve_name;
/*
* All members except 'meth' are handled by the method functions, even if
* they appear generic
*/
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 */
};
static ossl_inline int ec_point_is_compat(const EC_POINT *point,
const EC_GROUP *group)
{
if (group->meth != point->meth
|| (group->curve_name != 0
&& point->curve_name != 0
&& group->curve_name != point->curve_name))
return 0;
return 1;
}
NISTP224_PRE_COMP *EC_nistp224_pre_comp_dup(NISTP224_PRE_COMP *);
NISTP256_PRE_COMP *EC_nistp256_pre_comp_dup(NISTP256_PRE_COMP *);
NISTP521_PRE_COMP *EC_nistp521_pre_comp_dup(NISTP521_PRE_COMP *);
NISTZ256_PRE_COMP *EC_nistz256_pre_comp_dup(NISTZ256_PRE_COMP *);
NISTP256_PRE_COMP *EC_nistp256_pre_comp_dup(NISTP256_PRE_COMP *);
EC_PRE_COMP *EC_ec_pre_comp_dup(EC_PRE_COMP *);
void EC_pre_comp_free(EC_GROUP *group);
void EC_nistp224_pre_comp_free(NISTP224_PRE_COMP *);
void EC_nistp256_pre_comp_free(NISTP256_PRE_COMP *);
void EC_nistp521_pre_comp_free(NISTP521_PRE_COMP *);
void EC_nistz256_pre_comp_free(NISTZ256_PRE_COMP *);
void EC_ec_pre_comp_free(EC_PRE_COMP *);
/*
* method functions in ec_mult.c (ec_lib.c uses these as defaults if
* group->method->mul is 0)
*/
int ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
size_t num, const EC_POINT *points[], const BIGNUM *scalars[],
BN_CTX *);
int ec_wNAF_precompute_mult(EC_GROUP *group, BN_CTX *);
int ec_wNAF_have_precompute_mult(const EC_GROUP *group);
/* method functions in ecp_smpl.c */
int ec_GFp_simple_group_init(EC_GROUP *);
void ec_GFp_simple_group_finish(EC_GROUP *);
void ec_GFp_simple_group_clear_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 *);
int ec_GFp_simple_group_get_degree(const EC_GROUP *);
int ec_GFp_simple_group_check_discriminant(const EC_GROUP *, BN_CTX *);
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 *);
size_t ec_GFp_simple_point2oct(const EC_GROUP *, const EC_POINT *,
point_conversion_form_t form,
unsigned char *buf, size_t len, BN_CTX *);
int ec_GFp_simple_oct2point(const EC_GROUP *, EC_POINT *,
const unsigned char *buf, size_t len, 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 *);
int ec_GFp_simple_field_inv(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
BN_CTX *);
int ec_GFp_simple_blind_coordinates(const EC_GROUP *group, EC_POINT *p,
BN_CTX *ctx);
int ec_GFp_simple_ladder_pre(const EC_GROUP *group,
EC_POINT *r, EC_POINT *s,
EC_POINT *p, BN_CTX *ctx);
int ec_GFp_simple_ladder_step(const EC_GROUP *group,
EC_POINT *r, EC_POINT *s,
EC_POINT *p, BN_CTX *ctx);
int ec_GFp_simple_ladder_post(const EC_GROUP *group,
EC_POINT *r, EC_POINT *s,
EC_POINT *p, BN_CTX *ctx);
/* method functions in ecp_mont.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_group_clear_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_inv(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 *);
/* method functions in ecp_nist.c */
int ec_GFp_nist_group_copy(EC_GROUP *dest, const EC_GROUP *src);
int ec_GFp_nist_group_set_curve(EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
const BIGNUM *b, BN_CTX *);
int ec_GFp_nist_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
const BIGNUM *b, BN_CTX *);
int ec_GFp_nist_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
BN_CTX *);
/* method functions in ec2_smpl.c */
int ec_GF2m_simple_group_init(EC_GROUP *);
void ec_GF2m_simple_group_finish(EC_GROUP *);
void ec_GF2m_simple_group_clear_finish(EC_GROUP *);
int ec_GF2m_simple_group_copy(EC_GROUP *, const EC_GROUP *);
int ec_GF2m_simple_group_set_curve(EC_GROUP *, const BIGNUM *p,
const BIGNUM *a, const BIGNUM *b,
BN_CTX *);
int ec_GF2m_simple_group_get_curve(const EC_GROUP *, BIGNUM *p, BIGNUM *a,
BIGNUM *b, BN_CTX *);
int ec_GF2m_simple_group_get_degree(const EC_GROUP *);
int ec_GF2m_simple_group_check_discriminant(const EC_GROUP *, BN_CTX *);
int ec_GF2m_simple_point_init(EC_POINT *);
void ec_GF2m_simple_point_finish(EC_POINT *);
void ec_GF2m_simple_point_clear_finish(EC_POINT *);
int ec_GF2m_simple_point_copy(EC_POINT *, const EC_POINT *);
int ec_GF2m_simple_point_set_to_infinity(const EC_GROUP *, EC_POINT *);
int ec_GF2m_simple_point_set_affine_coordinates(const EC_GROUP *, EC_POINT *,
const BIGNUM *x,
const BIGNUM *y, BN_CTX *);
int ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *,
const EC_POINT *, BIGNUM *x,
BIGNUM *y, BN_CTX *);
int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *, EC_POINT *,
const BIGNUM *x, int y_bit,
BN_CTX *);
size_t ec_GF2m_simple_point2oct(const EC_GROUP *, const EC_POINT *,
point_conversion_form_t form,
unsigned char *buf, size_t len, BN_CTX *);
int ec_GF2m_simple_oct2point(const EC_GROUP *, EC_POINT *,
const unsigned char *buf, size_t len, BN_CTX *);
int ec_GF2m_simple_add(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
const EC_POINT *b, BN_CTX *);
int ec_GF2m_simple_dbl(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
BN_CTX *);
int ec_GF2m_simple_invert(const EC_GROUP *, EC_POINT *, BN_CTX *);
int ec_GF2m_simple_is_at_infinity(const EC_GROUP *, const EC_POINT *);
int ec_GF2m_simple_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
int ec_GF2m_simple_cmp(const EC_GROUP *, const EC_POINT *a, const EC_POINT *b,
BN_CTX *);
int ec_GF2m_simple_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
int ec_GF2m_simple_points_make_affine(const EC_GROUP *, size_t num,
EC_POINT *[], BN_CTX *);
int ec_GF2m_simple_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
const BIGNUM *b, BN_CTX *);
int ec_GF2m_simple_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
BN_CTX *);
int ec_GF2m_simple_field_div(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
const BIGNUM *b, BN_CTX *);
#ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
/* method functions in ecp_nistp224.c */
int ec_GFp_nistp224_group_init(EC_GROUP *group);
int ec_GFp_nistp224_group_set_curve(EC_GROUP *group, const BIGNUM *p,
const BIGNUM *a, const BIGNUM *n,
BN_CTX *);
int ec_GFp_nistp224_point_get_affine_coordinates(const EC_GROUP *group,
const EC_POINT *point,
BIGNUM *x, BIGNUM *y,
BN_CTX *ctx);
int ec_GFp_nistp224_mul(const EC_GROUP *group, EC_POINT *r,
const BIGNUM *scalar, size_t num,
const EC_POINT *points[], const BIGNUM *scalars[],
BN_CTX *);
int ec_GFp_nistp224_points_mul(const EC_GROUP *group, EC_POINT *r,
const BIGNUM *scalar, size_t num,
const EC_POINT *points[],
const BIGNUM *scalars[], BN_CTX *ctx);
int ec_GFp_nistp224_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
int ec_GFp_nistp224_have_precompute_mult(const EC_GROUP *group);
/* method functions in ecp_nistp256.c */
int ec_GFp_nistp256_group_init(EC_GROUP *group);
int ec_GFp_nistp256_group_set_curve(EC_GROUP *group, const BIGNUM *p,
const BIGNUM *a, const BIGNUM *n,
BN_CTX *);
int ec_GFp_nistp256_point_get_affine_coordinates(const EC_GROUP *group,
const EC_POINT *point,
BIGNUM *x, BIGNUM *y,
BN_CTX *ctx);
int ec_GFp_nistp256_mul(const EC_GROUP *group, EC_POINT *r,
const BIGNUM *scalar, size_t num,
const EC_POINT *points[], const BIGNUM *scalars[],
BN_CTX *);
int ec_GFp_nistp256_points_mul(const EC_GROUP *group, EC_POINT *r,
const BIGNUM *scalar, size_t num,
const EC_POINT *points[],
const BIGNUM *scalars[], BN_CTX *ctx);
int ec_GFp_nistp256_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
int ec_GFp_nistp256_have_precompute_mult(const EC_GROUP *group);
/* method functions in ecp_nistp521.c */
int ec_GFp_nistp521_group_init(EC_GROUP *group);
int ec_GFp_nistp521_group_set_curve(EC_GROUP *group, const BIGNUM *p,
const BIGNUM *a, const BIGNUM *n,
BN_CTX *);
int ec_GFp_nistp521_point_get_affine_coordinates(const EC_GROUP *group,
const EC_POINT *point,
BIGNUM *x, BIGNUM *y,
BN_CTX *ctx);
int ec_GFp_nistp521_mul(const EC_GROUP *group, EC_POINT *r,
const BIGNUM *scalar, size_t num,
const EC_POINT *points[], const BIGNUM *scalars[],
BN_CTX *);
int ec_GFp_nistp521_points_mul(const EC_GROUP *group, EC_POINT *r,
const BIGNUM *scalar, size_t num,
const EC_POINT *points[],
const BIGNUM *scalars[], BN_CTX *ctx);
int ec_GFp_nistp521_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
int ec_GFp_nistp521_have_precompute_mult(const EC_GROUP *group);
/* utility functions in ecp_nistputil.c */
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(unsigned char *sign,
unsigned char *digit, unsigned char in);
#endif
int ec_group_simple_order_bits(const EC_GROUP *group);
#ifdef ECP_NISTZ256_ASM
/** Returns GFp methods using montgomery multiplication, with x86-64 optimized
* P256. See http://eprint.iacr.org/2013/816.
* \return EC_METHOD object
*/
const EC_METHOD *EC_GFp_nistz256_method(void);
#endif
size_t ec_key_simple_priv2oct(const EC_KEY *eckey,
unsigned char *buf, size_t len);
int ec_key_simple_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len);
int ec_key_simple_generate_key(EC_KEY *eckey);
int ec_key_simple_generate_public_key(EC_KEY *eckey);
int ec_key_simple_check_key(const EC_KEY *eckey);
int ec_curve_nid_from_params(const EC_GROUP *group, BN_CTX *ctx);
/* EC_METHOD definitions */
struct ec_key_method_st {
const char *name;
int32_t flags;
int (*init)(EC_KEY *key);
void (*finish)(EC_KEY *key);
int (*copy)(EC_KEY *dest, const EC_KEY *src);
int (*set_group)(EC_KEY *key, const EC_GROUP *grp);
int (*set_private)(EC_KEY *key, const BIGNUM *priv_key);
int (*set_public)(EC_KEY *key, const EC_POINT *pub_key);
int (*keygen)(EC_KEY *key);
int (*compute_key)(unsigned char **pout, size_t *poutlen,
const EC_POINT *pub_key, const EC_KEY *ecdh);
int (*sign)(int type, const unsigned char *dgst, int dlen, unsigned char
*sig, unsigned int *siglen, const BIGNUM *kinv,
const BIGNUM *r, EC_KEY *eckey);
int (*sign_setup)(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
BIGNUM **rp);
ECDSA_SIG *(*sign_sig)(const unsigned char *dgst, int dgst_len,
const BIGNUM *in_kinv, const BIGNUM *in_r,
EC_KEY *eckey);
int (*verify)(int type, const unsigned char *dgst, int dgst_len,
const unsigned char *sigbuf, int sig_len, EC_KEY *eckey);
int (*verify_sig)(const unsigned char *dgst, int dgst_len,
const ECDSA_SIG *sig, EC_KEY *eckey);
};
#define EC_KEY_METHOD_DYNAMIC 1
int ossl_ec_key_gen(EC_KEY *eckey);
int ossl_ecdh_compute_key(unsigned char **pout, size_t *poutlen,
const EC_POINT *pub_key, const EC_KEY *ecdh);
int ecdh_simple_compute_key(unsigned char **pout, size_t *poutlen,
const EC_POINT *pub_key, const EC_KEY *ecdh);
struct ECDSA_SIG_st {
BIGNUM *r;
BIGNUM *s;
};
int ossl_ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
BIGNUM **rp);
int ossl_ecdsa_sign(int type, const unsigned char *dgst, int dlen,
unsigned char *sig, unsigned int *siglen,
const BIGNUM *kinv, const BIGNUM *r, EC_KEY *eckey);
ECDSA_SIG *ossl_ecdsa_sign_sig(const unsigned char *dgst, int dgst_len,
const BIGNUM *in_kinv, const BIGNUM *in_r,
EC_KEY *eckey);
int ossl_ecdsa_verify(int type, const unsigned char *dgst, int dgst_len,
const unsigned char *sigbuf, int sig_len, EC_KEY *eckey);
int ossl_ecdsa_verify_sig(const unsigned char *dgst, int dgst_len,
const ECDSA_SIG *sig, EC_KEY *eckey);
int ED25519_sign(uint8_t *out_sig, const uint8_t *message, size_t message_len,
const uint8_t public_key[32], const uint8_t private_key[32]);
int ED25519_verify(const uint8_t *message, size_t message_len,
const uint8_t signature[64], const uint8_t public_key[32]);
void ED25519_public_from_private(uint8_t out_public_key[32],
const uint8_t private_key[32]);
int X25519(uint8_t out_shared_key[32], const uint8_t private_key[32],
const uint8_t peer_public_value[32]);
void X25519_public_from_private(uint8_t out_public_value[32],
const uint8_t private_key[32]);
/*-
* This functions computes a single point multiplication over the EC group,
* using, at a high level, a Montgomery ladder with conditional swaps, with
* various timing attack defenses.
*
* It performs either a fixed point multiplication
* (scalar * generator)
* when point is NULL, or a variable point multiplication
* (scalar * point)
* when point is not NULL.
*
* `scalar` cannot be NULL and should be in the range [0,n) otherwise all
* constant time bets are off (where n is the cardinality of the EC group).
*
* This function expects `group->order` and `group->cardinality` to be well
* defined and non-zero: it fails with an error code otherwise.
*
* NB: This says nothing about the constant-timeness of the ladder step
* implementation (i.e., the default implementation is based on EC_POINT_add and
* EC_POINT_dbl, which of course are not constant time themselves) or the
* underlying multiprecision arithmetic.
*
* The product is stored in `r`.
*
* This is an internal function: callers are in charge of ensuring that the
* input parameters `group`, `r`, `scalar` and `ctx` are not NULL.
*
* Returns 1 on success, 0 otherwise.
*/
int ec_scalar_mul_ladder(const EC_GROUP *group, EC_POINT *r,
const BIGNUM *scalar, const EC_POINT *point,
BN_CTX *ctx);
int ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx);
static ossl_inline int ec_point_ladder_pre(const EC_GROUP *group,
EC_POINT *r, EC_POINT *s,
EC_POINT *p, BN_CTX *ctx)
{
if (group->meth->ladder_pre != NULL)
return group->meth->ladder_pre(group, r, s, p, ctx);
if (!EC_POINT_copy(s, p)
|| !EC_POINT_dbl(group, r, s, ctx))
return 0;
return 1;
}
static ossl_inline int ec_point_ladder_step(const EC_GROUP *group,
EC_POINT *r, EC_POINT *s,
EC_POINT *p, BN_CTX *ctx)
{
if (group->meth->ladder_step != NULL)
return group->meth->ladder_step(group, r, s, p, ctx);
if (!EC_POINT_add(group, s, r, s, ctx)
|| !EC_POINT_dbl(group, r, r, ctx))
return 0;
return 1;
}
static ossl_inline int ec_point_ladder_post(const EC_GROUP *group,
EC_POINT *r, EC_POINT *s,
EC_POINT *p, BN_CTX *ctx)
{
if (group->meth->ladder_post != NULL)
return group->meth->ladder_post(group, r, s, p, ctx);
return 1;
}
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