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-rw-r--r--crypto/ec/ec_lcl.h437
1 files changed, 298 insertions, 139 deletions
diff --git a/crypto/ec/ec_lcl.h b/crypto/ec/ec_lcl.h
index 969fd147ef93..e055ddab1c76 100644
--- a/crypto/ec/ec_lcl.h
+++ b/crypto/ec/ec_lcl.h
@@ -1,72 +1,11 @@
-/* crypto/ec/ec_lcl.h */
/*
- * Originally written by Bodo Moeller for the OpenSSL project.
- */
-/* ====================================================================
- * Copyright (c) 1998-2010 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.
+ * Copyright 2001-2018 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>
@@ -74,6 +13,9 @@
#include <openssl/obj_mac.h>
#include <openssl/ec.h>
#include <openssl/bn.h>
+#include "internal/refcount.h"
+#include "internal/ec_int.h"
+#include "curve448/curve448_lcl.h"
#if defined(__SUNPRO_C)
# if __SUNPRO_C >= 0x520
@@ -84,6 +26,12 @@
/* 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.
@@ -102,14 +50,14 @@ struct ec_method_st {
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_GFp, EC_GROUP_get_curve_GFp, */
- /* EC_GROUP_set_curve_GF2m, and EC_GROUP_get_curve_GF2m: */
+ /* 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 *);
/*
@@ -124,9 +72,9 @@ struct ec_method_st {
* used by EC_POINT_set_to_infinity,
* EC_POINT_set_Jprojective_coordinates_GFp,
* EC_POINT_get_Jprojective_coordinates_GFp,
- * EC_POINT_set_affine_coordinates_GFp, ..._GF2m,
- * EC_POINT_get_affine_coordinates_GFp, ..._GF2m,
- * EC_POINT_set_compressed_coordinates_GFp, ..._GF2m:
+ * 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 *,
@@ -172,6 +120,23 @@ struct ec_method_st {
* 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 *);
@@ -196,34 +161,52 @@ struct ec_method_st {
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 *);
-} /* EC_METHOD */ ;
+ /* 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);
+};
-typedef struct ec_extra_data_st {
- struct ec_extra_data_st *next;
- void *data;
- void *(*dup_func) (void *);
- void (*free_func) (void *);
- void (*clear_free_func) (void *);
-} EC_EXTRA_DATA; /* used in EC_GROUP */
+/*
+ * 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;
+ BIGNUM *order, *cofactor;
int curve_name; /* optional NID for named curve */
int asn1_flag; /* flag to control the asn1 encoding */
- /*
- * Kludge: upper bit of ans1_flag is used to denote structure
- * version. Is set, then last field is present. This is done
- * for interoperation with FIPS code.
- */
-#define EC_GROUP_ASN1_FLAG_MASK 0x7fffffff
-#define EC_GROUP_VERSION(p) (p->asn1_flag&~EC_GROUP_ASN1_FLAG_MASK)
point_conversion_form_t asn1_form;
unsigned char *seed; /* optional seed for parameters (appears in
* ASN1) */
size_t seed_len;
- EC_EXTRA_DATA *extra_data; /* linked list */
/*
* The following members are handled by the method functions, even if
* they appear generic
@@ -233,7 +216,7 @@ struct ec_group_st {
* curves over GF(2^m), this is the irreducible polynomial defining the
* field.
*/
- BIGNUM 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 =
@@ -249,7 +232,7 @@ struct ec_group_st {
* 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;
+ BIGNUM *a, *b;
/* enable optimized point arithmetics for special case */
int a_is_minus3;
/* method-specific (e.g., Montgomery structure) */
@@ -259,56 +242,89 @@ struct ec_group_st {
/* method-specific */
int (*field_mod_func) (BIGNUM *, const BIGNUM *, const BIGNUM *,
BN_CTX *);
- BN_MONT_CTX *mont_data; /* data for ECDSA inverse */
-} /* EC_GROUP */ ;
+ /* 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;
- int references;
+ CRYPTO_REF_COUNT references;
int flags;
- EC_EXTRA_DATA *method_data;
-} /* EC_KEY */ ;
-
-/*
- * Basically a 'mixin' for extra data, but available for EC_GROUPs/EC_KEYs
- * only (with visibility limited to 'package' level for now). We use the
- * function pointers as index for retrieval; this obviates global
- * ex_data-style index tables.
- */
-int EC_EX_DATA_set_data(EC_EXTRA_DATA **, void *data,
- void *(*dup_func) (void *),
- void (*free_func) (void *),
- void (*clear_free_func) (void *));
-void *EC_EX_DATA_get_data(const EC_EXTRA_DATA *, void *(*dup_func) (void *),
- void (*free_func) (void *),
- void (*clear_free_func) (void *));
-void EC_EX_DATA_free_data(EC_EXTRA_DATA **, void *(*dup_func) (void *),
- void (*free_func) (void *),
- void (*clear_free_func) (void *));
-void EC_EX_DATA_clear_free_data(EC_EXTRA_DATA **, void *(*dup_func) (void *),
- void (*free_func) (void *),
- void (*clear_free_func) (void *));
-void EC_EX_DATA_free_all_data(EC_EXTRA_DATA **);
-void EC_EX_DATA_clear_free_all_data(EC_EXTRA_DATA **);
+ 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 */
+ 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 */ ;
+};
+
+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
@@ -374,6 +390,17 @@ 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_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 *);
@@ -451,14 +478,6 @@ int ec_GF2m_simple_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
int ec_GF2m_simple_field_div(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
const BIGNUM *b, BN_CTX *);
-/* method functions in ec2_mult.c */
-int ec_GF2m_simple_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_GF2m_precompute_mult(EC_GROUP *group, BN_CTX *ctx);
-int ec_GF2m_have_precompute_mult(const EC_GROUP *group);
-
#ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
/* method functions in ecp_nistp224.c */
int ec_GFp_nistp224_group_init(EC_GROUP *group);
@@ -549,7 +568,7 @@ void ec_GFp_nistp_points_make_affine_internal(size_t num, void *point_array,
void ec_GFp_nistp_recode_scalar_bits(unsigned char *sign,
unsigned char *digit, unsigned char in);
#endif
-int ec_precompute_mont_data(EC_GROUP *);
+int ec_group_simple_order_bits(const EC_GROUP *group);
#ifdef ECP_NISTZ256_ASM
/** Returns GFp methods using montgomery multiplication, with x86-64 optimized
@@ -559,10 +578,150 @@ int ec_precompute_mont_data(EC_GROUP *);
const EC_METHOD *EC_GFp_nistz256_method(void);
#endif
-#ifdef OPENSSL_FIPS
-EC_GROUP *FIPS_ec_group_new_curve_gfp(const BIGNUM *p, const BIGNUM *a,
- const BIGNUM *b, BN_CTX *ctx);
-EC_GROUP *FIPS_ec_group_new_curve_gf2m(const BIGNUM *p, const BIGNUM *a,
- const BIGNUM *b, BN_CTX *ctx);
-EC_GROUP *FIPS_ec_group_new_by_curve_name(int nid);
-#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);
+
+/* 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;
+}