mbed TLS v2.16.7
ecp.h
Go to the documentation of this file.
1 
17 /*
18  * Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
19  * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
20  *
21  * This file is provided under the Apache License 2.0, or the
22  * GNU General Public License v2.0 or later.
23  *
24  * **********
25  * Apache License 2.0:
26  *
27  * Licensed under the Apache License, Version 2.0 (the "License"); you may
28  * not use this file except in compliance with the License.
29  * You may obtain a copy of the License at
30  *
31  * http://www.apache.org/licenses/LICENSE-2.0
32  *
33  * Unless required by applicable law or agreed to in writing, software
34  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
35  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
36  * See the License for the specific language governing permissions and
37  * limitations under the License.
38  *
39  * **********
40  *
41  * **********
42  * GNU General Public License v2.0 or later:
43  *
44  * This program is free software; you can redistribute it and/or modify
45  * it under the terms of the GNU General Public License as published by
46  * the Free Software Foundation; either version 2 of the License, or
47  * (at your option) any later version.
48  *
49  * This program is distributed in the hope that it will be useful,
50  * but WITHOUT ANY WARRANTY; without even the implied warranty of
51  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
52  * GNU General Public License for more details.
53  *
54  * You should have received a copy of the GNU General Public License along
55  * with this program; if not, write to the Free Software Foundation, Inc.,
56  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
57  *
58  * **********
59  *
60  * This file is part of Mbed TLS (https://tls.mbed.org)
61  */
62 
63 #ifndef MBEDTLS_ECP_H
64 #define MBEDTLS_ECP_H
65 
66 #if !defined(MBEDTLS_CONFIG_FILE)
67 #include "config.h"
68 #else
69 #include MBEDTLS_CONFIG_FILE
70 #endif
71 
72 #include "bignum.h"
73 
74 /*
75  * ECP error codes
76  */
77 #define MBEDTLS_ERR_ECP_BAD_INPUT_DATA -0x4F80
78 #define MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL -0x4F00
79 #define MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE -0x4E80
80 #define MBEDTLS_ERR_ECP_VERIFY_FAILED -0x4E00
81 #define MBEDTLS_ERR_ECP_ALLOC_FAILED -0x4D80
82 #define MBEDTLS_ERR_ECP_RANDOM_FAILED -0x4D00
83 #define MBEDTLS_ERR_ECP_INVALID_KEY -0x4C80
84 #define MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH -0x4C00
86 /* MBEDTLS_ERR_ECP_HW_ACCEL_FAILED is deprecated and should not be used. */
87 #define MBEDTLS_ERR_ECP_HW_ACCEL_FAILED -0x4B80
89 #define MBEDTLS_ERR_ECP_IN_PROGRESS -0x4B00
91 #ifdef __cplusplus
92 extern "C" {
93 #endif
94 
104 typedef enum
105 {
121 
127 #define MBEDTLS_ECP_DP_MAX 12
128 
133 {
135  uint16_t tls_id;
136  uint16_t bit_size;
137  const char *name;
139 
151 typedef struct mbedtls_ecp_point
152 {
156 }
158 
159 #if !defined(MBEDTLS_ECP_ALT)
160 /*
161  * default mbed TLS elliptic curve arithmetic implementation
162  *
163  * (in case MBEDTLS_ECP_ALT is defined then the developer has to provide an
164  * alternative implementation for the whole module and it will replace this
165  * one.)
166  */
167 
200 typedef struct mbedtls_ecp_group
201 {
210  size_t pbits;
211  size_t nbits;
214  unsigned int h;
215  int (*modp)(mbedtls_mpi *);
217  int (*t_pre)(mbedtls_ecp_point *, void *);
218  int (*t_post)(mbedtls_ecp_point *, void *);
219  void *t_data;
221  size_t T_size;
222 }
224 
233 #if !defined(MBEDTLS_ECP_MAX_BITS)
234 
237 #define MBEDTLS_ECP_MAX_BITS 521
238 #endif
239 
240 #define MBEDTLS_ECP_MAX_BYTES ( ( MBEDTLS_ECP_MAX_BITS + 7 ) / 8 )
241 #define MBEDTLS_ECP_MAX_PT_LEN ( 2 * MBEDTLS_ECP_MAX_BYTES + 1 )
242 
243 #if !defined(MBEDTLS_ECP_WINDOW_SIZE)
244 /*
245  * Maximum "window" size used for point multiplication.
246  * Default: 6.
247  * Minimum value: 2. Maximum value: 7.
248  *
249  * Result is an array of at most ( 1 << ( MBEDTLS_ECP_WINDOW_SIZE - 1 ) )
250  * points used for point multiplication. This value is directly tied to EC
251  * peak memory usage, so decreasing it by one should roughly cut memory usage
252  * by two (if large curves are in use).
253  *
254  * Reduction in size may reduce speed, but larger curves are impacted first.
255  * Sample performances (in ECDHE handshakes/s, with FIXED_POINT_OPTIM = 1):
256  * w-size: 6 5 4 3 2
257  * 521 145 141 135 120 97
258  * 384 214 209 198 177 146
259  * 256 320 320 303 262 226
260  * 224 475 475 453 398 342
261  * 192 640 640 633 587 476
262  */
263 #define MBEDTLS_ECP_WINDOW_SIZE 6
264 #endif /* MBEDTLS_ECP_WINDOW_SIZE */
265 
266 #if !defined(MBEDTLS_ECP_FIXED_POINT_OPTIM)
267 /*
268  * Trade memory for speed on fixed-point multiplication.
269  *
270  * This speeds up repeated multiplication of the generator (that is, the
271  * multiplication in ECDSA signatures, and half of the multiplications in
272  * ECDSA verification and ECDHE) by a factor roughly 3 to 4.
273  *
274  * The cost is increasing EC peak memory usage by a factor roughly 2.
275  *
276  * Change this value to 0 to reduce peak memory usage.
277  */
278 #define MBEDTLS_ECP_FIXED_POINT_OPTIM 1
279 #endif /* MBEDTLS_ECP_FIXED_POINT_OPTIM */
280 
281 /* \} name SECTION: Module settings */
282 
283 #else /* MBEDTLS_ECP_ALT */
284 #include "ecp_alt.h"
285 #endif /* MBEDTLS_ECP_ALT */
286 
287 #if defined(MBEDTLS_ECP_RESTARTABLE)
288 
294 typedef struct mbedtls_ecp_restart_mul mbedtls_ecp_restart_mul_ctx;
295 
301 typedef struct mbedtls_ecp_restart_muladd mbedtls_ecp_restart_muladd_ctx;
302 
306 typedef struct
307 {
308  unsigned ops_done;
309  unsigned depth;
310  mbedtls_ecp_restart_mul_ctx *rsm;
311  mbedtls_ecp_restart_muladd_ctx *ma;
313 
314 /*
315  * Operation counts for restartable functions
316  */
317 #define MBEDTLS_ECP_OPS_CHK 3
318 #define MBEDTLS_ECP_OPS_DBL 8
319 #define MBEDTLS_ECP_OPS_ADD 11
320 #define MBEDTLS_ECP_OPS_INV 120
333 int mbedtls_ecp_check_budget( const mbedtls_ecp_group *grp,
334  mbedtls_ecp_restart_ctx *rs_ctx,
335  unsigned ops );
336 
337 /* Utility macro for checking and updating ops budget */
338 #define MBEDTLS_ECP_BUDGET( ops ) \
339  MBEDTLS_MPI_CHK( mbedtls_ecp_check_budget( grp, rs_ctx, \
340  (unsigned) (ops) ) );
341 
342 #else /* MBEDTLS_ECP_RESTARTABLE */
343 
344 #define MBEDTLS_ECP_BUDGET( ops ) /* no-op; for compatibility */
345 
346 /* We want to declare restartable versions of existing functions anyway */
348 
349 #endif /* MBEDTLS_ECP_RESTARTABLE */
350 
359 typedef struct mbedtls_ecp_keypair
360 {
364 }
366 
367 /*
368  * Point formats, from RFC 4492's enum ECPointFormat
369  */
370 #define MBEDTLS_ECP_PF_UNCOMPRESSED 0
371 #define MBEDTLS_ECP_PF_COMPRESSED 1
373 /*
374  * Some other constants from RFC 4492
375  */
376 #define MBEDTLS_ECP_TLS_NAMED_CURVE 3
378 #if defined(MBEDTLS_ECP_RESTARTABLE)
379 
436 void mbedtls_ecp_set_max_ops( unsigned max_ops );
437 
444 int mbedtls_ecp_restart_is_enabled( void );
445 #endif /* MBEDTLS_ECP_RESTARTABLE */
446 
455 
465 
476 
487 
498 
505 
516 
523 
530 
539 
548 
549 #if defined(MBEDTLS_ECP_RESTARTABLE)
550 
556 void mbedtls_ecp_restart_init( mbedtls_ecp_restart_ctx *ctx );
557 
565 void mbedtls_ecp_restart_free( mbedtls_ecp_restart_ctx *ctx );
566 #endif /* MBEDTLS_ECP_RESTARTABLE */
567 
580 
593  const mbedtls_ecp_group *src );
594 
605 
616 
630  const mbedtls_ecp_point *Q );
631 
645  const char *x, const char *y );
646 
668  int format, size_t *olen,
669  unsigned char *buf, size_t buflen );
670 
695  const unsigned char *buf, size_t ilen );
696 
716  mbedtls_ecp_point *pt,
717  const unsigned char **buf, size_t len );
718 
742  const mbedtls_ecp_point *pt,
743  int format, size_t *olen,
744  unsigned char *buf, size_t blen );
745 
764 
783  const unsigned char **buf, size_t len );
784 
804  const unsigned char **buf,
805  size_t len );
825  size_t *olen,
826  unsigned char *buf, size_t blen );
827 
865  const mbedtls_mpi *m, const mbedtls_ecp_point *P,
866  int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
867 
899  const mbedtls_mpi *m, const mbedtls_ecp_point *P,
900  int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
901  mbedtls_ecp_restart_ctx *rs_ctx );
902 
933  const mbedtls_mpi *m, const mbedtls_ecp_point *P,
934  const mbedtls_mpi *n, const mbedtls_ecp_point *Q );
935 
972  const mbedtls_mpi *m, const mbedtls_ecp_point *P,
973  const mbedtls_mpi *n, const mbedtls_ecp_point *Q,
974  mbedtls_ecp_restart_ctx *rs_ctx );
975 
1004  const mbedtls_ecp_point *pt );
1005 
1026  const mbedtls_mpi *d );
1027 
1044  mbedtls_mpi *d,
1045  int (*f_rng)(void *, unsigned char *, size_t),
1046  void *p_rng );
1047 
1076  const mbedtls_ecp_point *G,
1078  int (*f_rng)(void *, unsigned char *, size_t),
1079  void *p_rng );
1080 
1105  mbedtls_ecp_point *Q,
1106  int (*f_rng)(void *, unsigned char *, size_t),
1107  void *p_rng );
1108 
1123  int (*f_rng)(void *, unsigned char *, size_t),
1124  void *p_rng );
1125 
1144  const mbedtls_ecp_keypair *prv );
1145 
1146 #if defined(MBEDTLS_SELF_TEST)
1147 
1154 int mbedtls_ecp_self_test( int verbose );
1155 
1156 #endif /* MBEDTLS_SELF_TEST */
1157 
1158 #ifdef __cplusplus
1159 }
1160 #endif
1161 
1162 #endif /* ecp.h */
uint16_t tls_id
Definition: ecp.h:135
int(* modp)(mbedtls_mpi *)
Definition: ecp.h:215
int mbedtls_ecp_is_zero(mbedtls_ecp_point *pt)
This function checks if a point is the point at infinity.
mbedtls_mpi N
Definition: ecp.h:209
int mbedtls_ecp_mul_restartable(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, const mbedtls_mpi *m, const mbedtls_ecp_point *P, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng, mbedtls_ecp_restart_ctx *rs_ctx)
This function performs multiplication of a point by an integer: R = m * P in a restartable way...
int(* t_post)(mbedtls_ecp_point *, void *)
Definition: ecp.h:218
mbedtls_mpi Z
Definition: ecp.h:155
int mbedtls_ecp_muladd(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, const mbedtls_mpi *m, const mbedtls_ecp_point *P, const mbedtls_mpi *n, const mbedtls_ecp_point *Q)
This function performs multiplication and addition of two points by integers: R = m * P + n * Q...
int mbedtls_ecp_check_pub_priv(const mbedtls_ecp_keypair *pub, const mbedtls_ecp_keypair *prv)
This function checks that the keypair objects pub and prv have the same group and the same public poi...
int mbedtls_ecp_point_read_binary(const mbedtls_ecp_group *grp, mbedtls_ecp_point *P, const unsigned char *buf, size_t ilen)
This function imports a point from unsigned binary data.
mbedtls_mpi Y
Definition: ecp.h:154
int mbedtls_ecp_muladd_restartable(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, const mbedtls_mpi *m, const mbedtls_ecp_point *P, const mbedtls_mpi *n, const mbedtls_ecp_point *Q, mbedtls_ecp_restart_ctx *rs_ctx)
This function performs multiplication and addition of two points by integers: R = m * P + n * Q in a ...
mbedtls_ecp_group grp
Definition: ecp.h:361
struct mbedtls_ecp_curve_info mbedtls_ecp_curve_info
The ECP key-pair structure.
Definition: ecp.h:359
int mbedtls_ecp_set_zero(mbedtls_ecp_point *pt)
This function sets a point to the point at infinity.
int mbedtls_ecp_copy(mbedtls_ecp_point *P, const mbedtls_ecp_point *Q)
This function copies the contents of point Q into point P.
const mbedtls_ecp_group_id * mbedtls_ecp_grp_id_list(void)
This function retrieves the list of internal group identifiers of all supported curves in the order o...
int mbedtls_ecp_group_copy(mbedtls_ecp_group *dst, const mbedtls_ecp_group *src)
This function copies the contents of group src into group dst.
Configuration options (set of defines)
size_t nbits
Definition: ecp.h:211
struct mbedtls_ecp_group mbedtls_ecp_group
The ECP group structure.
int mbedtls_ecp_gen_keypair(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 ECP keypair.
void mbedtls_ecp_point_free(mbedtls_ecp_point *pt)
This function frees the components of a point.
int mbedtls_ecp_gen_privkey(const mbedtls_ecp_group *grp, mbedtls_mpi *d, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
This function generates a private key.
void mbedtls_ecp_keypair_init(mbedtls_ecp_keypair *key)
This function initializes a key pair as an invalid one.
size_t pbits
Definition: ecp.h:210
mbedtls_mpi X
Definition: ecp.h:153
Multi-precision integer library.
int mbedtls_ecp_gen_key(mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
This function generates an ECP key.
The ECP group structure.
Definition: ecp.h:200
int mbedtls_ecp_check_privkey(const mbedtls_ecp_group *grp, const mbedtls_mpi *d)
This function checks that an mbedtls_mpi is a valid private key for this curve.
mbedtls_ecp_group_id id
Definition: ecp.h:202
const mbedtls_ecp_curve_info * mbedtls_ecp_curve_info_from_grp_id(mbedtls_ecp_group_id grp_id)
This function retrieves curve information from an internal group identifier.
int mbedtls_ecp_tls_write_group(const mbedtls_ecp_group *grp, size_t *olen, unsigned char *buf, size_t blen)
This function exports an elliptic curve as a TLS ECParameters record as defined in RFC 4492...
void mbedtls_ecp_group_free(mbedtls_ecp_group *grp)
This function frees the components of an ECP group.
int mbedtls_ecp_mul(mbedtls_ecp_group *grp, mbedtls_ecp_point *R, const mbedtls_mpi *m, const mbedtls_ecp_point *P, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
This function performs a scalar multiplication of a point by an integer: R = m * P.
int mbedtls_ecp_check_pubkey(const mbedtls_ecp_group *grp, const mbedtls_ecp_point *pt)
This function checks that a point is a valid public key on this curve.
mbedtls_mpi A
Definition: ecp.h:204
mbedtls_mpi P
Definition: ecp.h:203
void mbedtls_ecp_keypair_free(mbedtls_ecp_keypair *key)
This function frees the components of a key pair.
struct mbedtls_ecp_keypair mbedtls_ecp_keypair
The ECP key-pair structure.
int mbedtls_ecp_tls_read_group(mbedtls_ecp_group *grp, const unsigned char **buf, size_t len)
This function sets up an ECP group context from a TLS ECParameters record as defined in RFC 4492...
void mbedtls_ecp_restart_ctx
Definition: ecp.h:347
mbedtls_ecp_point Q
Definition: ecp.h:363
void * t_data
Definition: ecp.h:219
void mbedtls_ecp_point_init(mbedtls_ecp_point *pt)
This function initializes a point as zero.
mbedtls_ecp_group_id
Definition: ecp.h:104
int mbedtls_ecp_point_read_string(mbedtls_ecp_point *P, int radix, const char *x, const char *y)
This function imports a non-zero point from two ASCII strings.
int mbedtls_ecp_self_test(int verbose)
The ECP checkup routine.
int mbedtls_ecp_point_write_binary(const mbedtls_ecp_group *grp, const mbedtls_ecp_point *P, int format, size_t *olen, unsigned char *buf, size_t buflen)
This function exports a point into unsigned binary data.
const mbedtls_ecp_curve_info * mbedtls_ecp_curve_info_from_tls_id(uint16_t tls_id)
This function retrieves curve information from a TLS NamedCurve value.
int mbedtls_ecp_tls_read_point(const mbedtls_ecp_group *grp, mbedtls_ecp_point *pt, const unsigned char **buf, size_t len)
This function imports a point from a TLS ECPoint record.
mbedtls_ecp_group_id grp_id
Definition: ecp.h:134
int mbedtls_ecp_tls_read_group_id(mbedtls_ecp_group_id *grp, const unsigned char **buf, size_t len)
This function extracts an elliptic curve group ID from a TLS ECParameters record as defined in RFC 44...
int mbedtls_ecp_gen_keypair_base(mbedtls_ecp_group *grp, const mbedtls_ecp_point *G, mbedtls_mpi *d, mbedtls_ecp_point *Q, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
This function generates a keypair with a configurable base point.
mbedtls_mpi d
Definition: ecp.h:362
unsigned int h
Definition: ecp.h:214
int mbedtls_ecp_point_cmp(const mbedtls_ecp_point *P, const mbedtls_ecp_point *Q)
This function compares two points.
int mbedtls_ecp_tls_write_point(const mbedtls_ecp_group *grp, const mbedtls_ecp_point *pt, int format, size_t *olen, unsigned char *buf, size_t blen)
This function exports a point as a TLS ECPoint record defined in RFC 4492, Section 5...
size_t T_size
Definition: ecp.h:221
mbedtls_ecp_point * T
Definition: ecp.h:220
mbedtls_ecp_point G
Definition: ecp.h:208
MPI structure.
Definition: bignum.h:212
struct mbedtls_ecp_point mbedtls_ecp_point
The ECP point structure, in Jacobian coordinates.
The ECP point structure, in Jacobian coordinates.
Definition: ecp.h:151
const mbedtls_ecp_curve_info * mbedtls_ecp_curve_info_from_name(const char *name)
This function retrieves curve information from a human-readable name.
const mbedtls_ecp_curve_info * mbedtls_ecp_curve_list(void)
This function retrieves the information defined in mbedtls_ecp_curve_info() for all supported curves ...
const char * name
Definition: ecp.h:137
int(* t_pre)(mbedtls_ecp_point *, void *)
Definition: ecp.h:217
int mbedtls_ecp_group_load(mbedtls_ecp_group *grp, mbedtls_ecp_group_id id)
This function sets up an ECP group context from a standardized set of domain parameters.
uint16_t bit_size
Definition: ecp.h:136
mbedtls_mpi B
Definition: ecp.h:206
void mbedtls_ecp_group_init(mbedtls_ecp_group *grp)
This function initializes an ECP group context without loading any domain parameters.