mbed TLS v2.16.3
ecdh.h
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1 
15 /*
16  * Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
17  * SPDX-License-Identifier: Apache-2.0
18  *
19  * Licensed under the Apache License, Version 2.0 (the "License"); you may
20  * not use this file except in compliance with the License.
21  * You may obtain a copy of the License at
22  *
23  * http://www.apache.org/licenses/LICENSE-2.0
24  *
25  * Unless required by applicable law or agreed to in writing, software
26  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
27  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
28  * See the License for the specific language governing permissions and
29  * limitations under the License.
30  *
31  * This file is part of Mbed TLS (https://tls.mbed.org)
32  */
33 
34 #ifndef MBEDTLS_ECDH_H
35 #define MBEDTLS_ECDH_H
36 
37 #if !defined(MBEDTLS_CONFIG_FILE)
38 #include "config.h"
39 #else
40 #include MBEDTLS_CONFIG_FILE
41 #endif
42 
43 #include "ecp.h"
44 
45 /*
46  * Use a backward compatible ECDH context.
47  *
48  * This flag is always enabled for now and future versions might add a
49  * configuration option that conditionally undefines this flag.
50  * The configuration option in question may have a different name.
51  *
52  * Features undefining this flag, must have a warning in their description in
53  * config.h stating that the feature breaks backward compatibility.
54  */
55 #define MBEDTLS_ECDH_LEGACY_CONTEXT
56 
57 #ifdef __cplusplus
58 extern "C" {
59 #endif
60 
64 typedef enum
65 {
69 
70 #if !defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
71 
77 typedef enum
78 {
79  MBEDTLS_ECDH_VARIANT_NONE = 0,
80  MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0,
81 } mbedtls_ecdh_variant;
82 
90 typedef struct mbedtls_ecdh_context_mbed
91 {
92  mbedtls_ecp_group grp;
93  mbedtls_mpi d;
96  mbedtls_mpi z;
97 #if defined(MBEDTLS_ECP_RESTARTABLE)
99 #endif
100 } mbedtls_ecdh_context_mbed;
101 #endif
102 
110 typedef struct mbedtls_ecdh_context
111 {
112 #if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
122 #if defined(MBEDTLS_ECP_RESTARTABLE)
123  int restart_enabled;
125 #endif /* MBEDTLS_ECP_RESTARTABLE */
126 #else
127  uint8_t point_format;
129  mbedtls_ecp_group_id grp_id;
130  mbedtls_ecdh_variant var;
131  union
132  {
133  mbedtls_ecdh_context_mbed mbed_ecdh;
134  } ctx;
137 #if defined(MBEDTLS_ECP_RESTARTABLE)
138  uint8_t restart_enabled;
143 #endif /* MBEDTLS_ECP_RESTARTABLE */
144 #endif /* MBEDTLS_ECDH_LEGACY_CONTEXT */
145 }
147 
174  int (*f_rng)(void *, unsigned char *, size_t),
175  void *p_rng );
176 
212  const mbedtls_ecp_point *Q, const mbedtls_mpi *d,
213  int (*f_rng)(void *, unsigned char *, size_t),
214  void *p_rng );
215 
222 
240  mbedtls_ecp_group_id grp_id );
241 
250 
276 int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
277  unsigned char *buf, size_t blen,
278  int (*f_rng)(void *, unsigned char *, size_t),
279  void *p_rng );
280 
306  const unsigned char **buf,
307  const unsigned char *end );
308 
329  const mbedtls_ecp_keypair *key,
330  mbedtls_ecdh_side side );
331 
358 int mbedtls_ecdh_make_public( mbedtls_ecdh_context *ctx, size_t *olen,
359  unsigned char *buf, size_t blen,
360  int (*f_rng)(void *, unsigned char *, size_t),
361  void *p_rng );
362 
383  const unsigned char *buf, size_t blen );
384 
415 int mbedtls_ecdh_calc_secret( mbedtls_ecdh_context *ctx, size_t *olen,
416  unsigned char *buf, size_t blen,
417  int (*f_rng)(void *, unsigned char *, size_t),
418  void *p_rng );
419 
420 #if defined(MBEDTLS_ECP_RESTARTABLE)
421 
433 void mbedtls_ecdh_enable_restart( mbedtls_ecdh_context *ctx );
434 #endif /* MBEDTLS_ECP_RESTARTABLE */
435 
436 #ifdef __cplusplus
437 }
438 #endif
439 
440 #endif /* ecdh.h */
mbedtls_ecdh_context::z
mbedtls_mpi z
Definition: ecdh.h:117
mbedtls_ecp_group
The ECP group structure.
Definition: ecp.h:173
ecp.h
This file provides an API for Elliptic Curves over GF(P) (ECP).
mbedtls_ecdh_calc_secret
int mbedtls_ecdh_calc_secret(mbedtls_ecdh_context *ctx, size_t *olen, unsigned char *buf, size_t blen, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
This function derives and exports the shared secret.
mbedtls_ecdh_context::d
mbedtls_mpi d
Definition: ecdh.h:114
mbedtls_mpi
MPI structure.
Definition: bignum.h:185
mbedtls_ecdh_init
void mbedtls_ecdh_init(mbedtls_ecdh_context *ctx)
This function initializes an ECDH context.
mbedtls_ecdh_make_params
int mbedtls_ecdh_make_params(mbedtls_ecdh_context *ctx, size_t *olen, unsigned char *buf, size_t blen, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
This function generates an EC key pair and exports its in the format used in a TLS ServerKeyExchange ...
mbedtls_ecdh_context
The ECDH context structure.
Definition: ecdh.h:110
mbedtls_ecdh_context::_d
mbedtls_mpi _d
Definition: ecdh.h:121
mbedtls_ecp_restart_ctx
void mbedtls_ecp_restart_ctx
Definition: ecp.h:320
mbedtls_ecdh_context
struct mbedtls_ecdh_context mbedtls_ecdh_context
The ECDH context structure.
mbedtls_ecdh_context::Vi
mbedtls_ecp_point Vi
Definition: ecdh.h:119
mbedtls_ecdh_context::grp
mbedtls_ecp_group grp
Definition: ecdh.h:113
mbedtls_ecp_keypair
The ECP key-pair structure.
Definition: ecp.h:332
mbedtls_ecp_group_id
mbedtls_ecp_group_id
Definition: ecp.h:77
mbedtls_ecdh_context::point_format
int point_format
Definition: ecdh.h:118
mbedtls_ecdh_context::Qp
mbedtls_ecp_point Qp
Definition: ecdh.h:116
mbedtls_ecdh_context::Q
mbedtls_ecp_point Q
Definition: ecdh.h:115
mbedtls_ecdh_gen_public
int mbedtls_ecdh_gen_public(mbedtls_ecp_group *grp, mbedtls_mpi *d, mbedtls_ecp_point *Q, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
This function generates an ECDH keypair on an elliptic curve.
mbedtls_ecdh_free
void mbedtls_ecdh_free(mbedtls_ecdh_context *ctx)
This function frees a context.
mbedtls_ecdh_side
mbedtls_ecdh_side
Definition: ecdh.h:64
MBEDTLS_ECDH_THEIRS
@ MBEDTLS_ECDH_THEIRS
Definition: ecdh.h:67
mbedtls_ecdh_context::Vf
mbedtls_ecp_point Vf
Definition: ecdh.h:120
mbedtls_ecdh_read_public
int mbedtls_ecdh_read_public(mbedtls_ecdh_context *ctx, const unsigned char *buf, size_t blen)
This function parses and processes the ECDHE payload of a TLS ClientKeyExchange message.
mbedtls_ecdh_make_public
int mbedtls_ecdh_make_public(mbedtls_ecdh_context *ctx, size_t *olen, unsigned char *buf, size_t blen, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
This function generates a public key and exports it as a TLS ClientKeyExchange payload.
config.h
Configuration options (set of defines)
mbedtls_ecdh_compute_shared
int mbedtls_ecdh_compute_shared(mbedtls_ecp_group *grp, mbedtls_mpi *z, const mbedtls_ecp_point *Q, const mbedtls_mpi *d, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
This function computes the shared secret.
mbedtls_ecp_point
The ECP point structure, in Jacobian coordinates.
Definition: ecp.h:124
MBEDTLS_ECDH_OURS
@ MBEDTLS_ECDH_OURS
Definition: ecdh.h:66
mbedtls_ecdh_read_params
int mbedtls_ecdh_read_params(mbedtls_ecdh_context *ctx, const unsigned char **buf, const unsigned char *end)
This function parses the ECDHE parameters in a TLS ServerKeyExchange handshake message.
mbedtls_ecdh_get_params
int mbedtls_ecdh_get_params(mbedtls_ecdh_context *ctx, const mbedtls_ecp_keypair *key, mbedtls_ecdh_side side)
This function sets up an ECDH context from an EC key.
mbedtls_ecdh_setup
int mbedtls_ecdh_setup(mbedtls_ecdh_context *ctx, mbedtls_ecp_group_id grp_id)
This function sets up the ECDH context with the information given.