ecp.h File Reference

Detailed Description

Elliptic curves over GF(p)

Copyright (C) 2006-2015, ARM Limited, All Rights Reserved SPDX-License-Identifier: Apache-2.0

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

This file is part of mbed TLS (https://tls.mbed.org)

Definition in file ecp.h.

#include "bignum.h"

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Data Structures
struct	mbedtls_ecp_curve_info
	Curve information for use by other modules. More...
struct	mbedtls_ecp_point
	ECP point structure (jacobian coordinates) More...
struct	mbedtls_ecp_group
	ECP group structure. More...
struct	mbedtls_ecp_keypair
	ECP key pair structure. More...

Macros
#define	MBEDTLS_ERR_ECP_BAD_INPUT_DATA   -0x4F80
	Bad input parameters to function. More...
#define	MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL   -0x4F00
	The buffer is too small to write to. More...
#define	MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE   -0x4E80
	Requested curve not available. More...
#define	MBEDTLS_ERR_ECP_VERIFY_FAILED   -0x4E00
	The signature is not valid. More...
#define	MBEDTLS_ERR_ECP_ALLOC_FAILED   -0x4D80
	Memory allocation failed. More...
#define	MBEDTLS_ERR_ECP_RANDOM_FAILED   -0x4D00
	Generation of random value, such as (ephemeral) key, failed. More...
#define	MBEDTLS_ERR_ECP_INVALID_KEY   -0x4C80
	Invalid private or public key. More...
#define	MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH   -0x4C00
	Signature is valid but shorter than the user-supplied length. More...
#define	MBEDTLS_ECP_DP_MAX   12
	Number of supported curves (plus one for NONE). More...
#define	MBEDTLS_ECP_PF_UNCOMPRESSED   0
	Uncompressed point format. More...
#define	MBEDTLS_ECP_PF_COMPRESSED   1
	Compressed point format. More...
#define	MBEDTLS_ECP_TLS_NAMED_CURVE   3
	ECCurveType's named_curve. More...
SECTION: Module settings
The configuration options you can set for this module are in this section. Either change them in config.h or define them on the compiler command line.
#define	MBEDTLS_ECP_MAX_BYTES   ( ( MBEDTLS_ECP_MAX_BITS + 7 ) / 8 )
#define	MBEDTLS_ECP_MAX_PT_LEN   ( 2 * MBEDTLS_ECP_MAX_BYTES + 1 )

Enumerations
enum	mbedtls_ecp_group_id {   MBEDTLS_ECP_DP_NONE = 0, MBEDTLS_ECP_DP_SECP192R1, MBEDTLS_ECP_DP_SECP224R1, MBEDTLS_ECP_DP_SECP256R1,   MBEDTLS_ECP_DP_SECP384R1, MBEDTLS_ECP_DP_SECP521R1, MBEDTLS_ECP_DP_BP256R1, MBEDTLS_ECP_DP_BP384R1,   MBEDTLS_ECP_DP_BP512R1, MBEDTLS_ECP_DP_CURVE25519, MBEDTLS_ECP_DP_SECP192K1, MBEDTLS_ECP_DP_SECP224K1,   MBEDTLS_ECP_DP_SECP256K1 }
	Domain parameters (curve, subgroup and generator) identifiers. More...

Functions
const mbedtls_ecp_curve_info *	mbedtls_ecp_curve_list (void)
	Get the list of supported curves in order of preferrence (full information) More...
const mbedtls_ecp_group_id *	mbedtls_ecp_grp_id_list (void)
	Get the list of supported curves in order of preferrence (grp_id only) More...
const mbedtls_ecp_curve_info *	mbedtls_ecp_curve_info_from_grp_id (mbedtls_ecp_group_id grp_id)
	Get curve information from an internal group identifier. More...
const mbedtls_ecp_curve_info *	mbedtls_ecp_curve_info_from_tls_id (uint16_t tls_id)
	Get curve information from a TLS NamedCurve value. More...
const mbedtls_ecp_curve_info *	mbedtls_ecp_curve_info_from_name (const char *name)
	Get curve information from a human-readable name. More...
void	mbedtls_ecp_point_init (mbedtls_ecp_point *pt)
	Initialize a point (as zero) More...
void	mbedtls_ecp_group_init (mbedtls_ecp_group *grp)
	Initialize a group (to something meaningless) More...
void	mbedtls_ecp_keypair_init (mbedtls_ecp_keypair *key)
	Initialize a key pair (as an invalid one) More...
void	mbedtls_ecp_point_free (mbedtls_ecp_point *pt)
	Free the components of a point. More...
void	mbedtls_ecp_group_free (mbedtls_ecp_group *grp)
	Free the components of an ECP group. More...
void	mbedtls_ecp_keypair_free (mbedtls_ecp_keypair *key)
	Free the components of a key pair. More...
int	mbedtls_ecp_copy (mbedtls_ecp_point *P, const mbedtls_ecp_point *Q)
	Copy the contents of point Q into P. More...
int	mbedtls_ecp_group_copy (mbedtls_ecp_group *dst, const mbedtls_ecp_group *src)
	Copy the contents of a group object. More...
int	mbedtls_ecp_set_zero (mbedtls_ecp_point *pt)
	Set a point to zero. More...
int	mbedtls_ecp_is_zero (mbedtls_ecp_point *pt)
	Tell if a point is zero. More...
int	mbedtls_ecp_point_cmp (const mbedtls_ecp_point *P, const mbedtls_ecp_point *Q)
	Compare two points. More...
int	mbedtls_ecp_point_read_string (mbedtls_ecp_point *P, int radix, const char *x, const char *y)
	Import a non-zero point from two ASCII strings. More...
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)
	Export a point into unsigned binary data. More...
int	mbedtls_ecp_point_read_binary (const mbedtls_ecp_group *grp, mbedtls_ecp_point *P, const unsigned char *buf, size_t ilen)
	Import a point from unsigned binary data. More...
int	mbedtls_ecp_tls_read_point (const mbedtls_ecp_group *grp, mbedtls_ecp_point *pt, const unsigned char **buf, size_t len)
	Import a point from a TLS ECPoint record. More...
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)
	Export a point as a TLS ECPoint record. More...
int	mbedtls_ecp_group_load (mbedtls_ecp_group *grp, mbedtls_ecp_group_id index)
	Set a group using well-known domain parameters. More...
int	mbedtls_ecp_tls_read_group (mbedtls_ecp_group *grp, const unsigned char **buf, size_t len)
	Set a group from a TLS ECParameters record. More...
int	mbedtls_ecp_tls_write_group (const mbedtls_ecp_group *grp, size_t *olen, unsigned char *buf, size_t blen)
	Write the TLS ECParameters record for a group. More...
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)
	Multiplication by an integer: R = m * P (Not thread-safe to use same group in multiple threads) More...
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)
	Multiplication and addition of two points by integers: R = m * P + n * Q (Not thread-safe to use same group in multiple threads) More...
int	mbedtls_ecp_check_pubkey (const mbedtls_ecp_group *grp, const mbedtls_ecp_point *pt)
	Check that a point is a valid public key on this curve. More...
int	mbedtls_ecp_check_privkey (const mbedtls_ecp_group *grp, const mbedtls_mpi *d)
	Check that an mbedtls_mpi is a valid private key for this curve. More...
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)
	Generate a keypair with configurable base point. More...
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)
	Generate a keypair. More...
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)
	Generate a keypair. More...
int	mbedtls_ecp_check_pub_priv (const mbedtls_ecp_keypair *pub, const mbedtls_ecp_keypair *prv)
	Check a public-private key pair. More...

Macro Definition Documentation

#define MBEDTLS_ECP_DP_MAX   12

Number of supported curves (plus one for NONE).

(Montgomery curves excluded for now.)

Definition at line 82 of file ecp.h.

#define MBEDTLS_ECP_MAX_BYTES   ( ( MBEDTLS_ECP_MAX_BITS + 7 ) / 8 )

Definition at line 186 of file ecp.h.

#define MBEDTLS_ECP_MAX_PT_LEN   ( 2 * MBEDTLS_ECP_MAX_BYTES + 1 )

Definition at line 187 of file ecp.h.

#define MBEDTLS_ECP_PF_COMPRESSED   1

Compressed point format.

Definition at line 234 of file ecp.h.

#define MBEDTLS_ECP_PF_UNCOMPRESSED   0

Uncompressed point format.

Definition at line 233 of file ecp.h.

#define MBEDTLS_ECP_TLS_NAMED_CURVE   3

ECCurveType's named_curve.

Definition at line 239 of file ecp.h.

#define MBEDTLS_ERR_ECP_ALLOC_FAILED   -0x4D80

Memory allocation failed.

Definition at line 35 of file ecp.h.

#define MBEDTLS_ERR_ECP_BAD_INPUT_DATA   -0x4F80

Bad input parameters to function.

Definition at line 31 of file ecp.h.

#define MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL   -0x4F00

The buffer is too small to write to.

Definition at line 32 of file ecp.h.

#define MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE   -0x4E80

Requested curve not available.

Definition at line 33 of file ecp.h.

#define MBEDTLS_ERR_ECP_INVALID_KEY   -0x4C80

Invalid private or public key.

Definition at line 37 of file ecp.h.

#define MBEDTLS_ERR_ECP_RANDOM_FAILED   -0x4D00

Generation of random value, such as (ephemeral) key, failed.

Definition at line 36 of file ecp.h.

#define MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH   -0x4C00

Signature is valid but shorter than the user-supplied length.

Definition at line 38 of file ecp.h.

#define MBEDTLS_ERR_ECP_VERIFY_FAILED   -0x4E00

The signature is not valid.

Definition at line 34 of file ecp.h.

Enumeration Type Documentation

enum mbedtls_ecp_group_id

Domain parameters (curve, subgroup and generator) identifiers.

Only curves over prime fields are supported.

Warning

This library does not support validation of arbitrary domain parameters. Therefore, only well-known domain parameters from trusted sources should be used. See mbedtls_ecp_group_load().

Enumerator
MBEDTLS_ECP_DP_NONE
MBEDTLS_ECP_DP_SECP192R1	192-bits NIST curve
MBEDTLS_ECP_DP_SECP224R1	224-bits NIST curve
MBEDTLS_ECP_DP_SECP256R1	256-bits NIST curve
MBEDTLS_ECP_DP_SECP384R1	384-bits NIST curve
MBEDTLS_ECP_DP_SECP521R1	521-bits NIST curve
MBEDTLS_ECP_DP_BP256R1	256-bits Brainpool curve
MBEDTLS_ECP_DP_BP384R1	384-bits Brainpool curve
MBEDTLS_ECP_DP_BP512R1	512-bits Brainpool curve
MBEDTLS_ECP_DP_CURVE25519	Curve25519
MBEDTLS_ECP_DP_SECP192K1	192-bits "Koblitz" curve
MBEDTLS_ECP_DP_SECP224K1	224-bits "Koblitz" curve
MBEDTLS_ECP_DP_SECP256K1	256-bits "Koblitz" curve

Definition at line 60 of file ecp.h.

Function Documentation

int mbedtls_ecp_check_privkey	(	const mbedtls_ecp_group *	grp,
		const mbedtls_mpi *	d
	)

Check that an mbedtls_mpi is a valid private key for this curve.

Parameters

grp	Group used
d	Integer to check

Returns

0 if point is a valid private key, MBEDTLS_ERR_ECP_INVALID_KEY otherwise.

Note

Uses bare components rather than an mbedtls_ecp_keypair structure in order to ease use with other structures such as mbedtls_ecdh_context of mbedtls_ecdsa_context.

int mbedtls_ecp_check_pub_priv	(	const mbedtls_ecp_keypair *	pub,
		const mbedtls_ecp_keypair *	prv
	)

Check a public-private key pair.

Parameters

pub	Keypair structure holding a public key
prv	Keypair structure holding a private (plus public) key

Returns

0 if successful (keys are valid and match), or MBEDTLS_ERR_ECP_BAD_INPUT_DATA, or a MBEDTLS_ERR_ECP_XXX or MBEDTLS_ERR_MPI_XXX code.

int mbedtls_ecp_check_pubkey	(	const mbedtls_ecp_group *	grp,
		const mbedtls_ecp_point *	pt
	)

Check that a point is a valid public key on this curve.

Parameters

grp	Curve/group the point should belong to
pt	Point to check

Returns

0 if point is a valid public key, MBEDTLS_ERR_ECP_INVALID_KEY otherwise.

Note

This function only checks the point is non-zero, has valid coordinates and lies on the curve, but not that it is indeed a multiple of G. This is additional check is more expensive, isn't required by standards, and shouldn't be necessary if the group used has a small cofactor. In particular, it is useless for the NIST groups which all have a cofactor of 1.

Uses bare components rather than an mbedtls_ecp_keypair structure in order to ease use with other structures such as mbedtls_ecdh_context of mbedtls_ecdsa_context.

int mbedtls_ecp_copy	(	mbedtls_ecp_point *	P,
		const mbedtls_ecp_point *	Q
	)

Copy the contents of point Q into P.

Parameters

P	Destination point
Q	Source point

Returns

0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed

const mbedtls_ecp_curve_info* mbedtls_ecp_curve_info_from_grp_id

(

mbedtls_ecp_group_id

grp_id

)

Get curve information from an internal group identifier.

Parameters

grp_id

A MBEDTLS_ECP_DP_XXX value

Returns

The associated curve information or NULL

const mbedtls_ecp_curve_info* mbedtls_ecp_curve_info_from_name

(

const char *

name

)

Get curve information from a human-readable name.

Parameters

name

The name

Returns

The associated curve information or NULL

const mbedtls_ecp_curve_info* mbedtls_ecp_curve_info_from_tls_id

(

uint16_t

tls_id

)

Get curve information from a TLS NamedCurve value.

Parameters

tls_id

A MBEDTLS_ECP_DP_XXX value

Returns

The associated curve information or NULL

const mbedtls_ecp_curve_info* mbedtls_ecp_curve_list

(

void

)

Get the list of supported curves in order of preferrence (full information)

Returns

A statically allocated array, the last entry is 0.

int mbedtls_ecp_gen_key	(	mbedtls_ecp_group_id	grp_id,
		mbedtls_ecp_keypair *	key,
		int(*)(void *, unsigned char *, size_t)	f_rng,
		void *	p_rng
	)

Generate a keypair.

Parameters

grp_id	ECP group identifier
key	Destination keypair
f_rng	RNG function
p_rng	RNG parameter

Returns

0 if successful, or a MBEDTLS_ERR_ECP_XXX or MBEDTLS_MPI_XXX error code

int mbedtls_ecp_gen_keypair	(	mbedtls_ecp_group *	grp,
		mbedtls_mpi *	d,
		mbedtls_ecp_point *	Q,
		int(*)(void *, unsigned char *, size_t)	f_rng,
		void *	p_rng
	)

Generate a keypair.

Parameters

grp	ECP group
d	Destination MPI (secret part)
Q	Destination point (public part)
f_rng	RNG function
p_rng	RNG parameter

Returns

0 if successful, or a MBEDTLS_ERR_ECP_XXX or MBEDTLS_MPI_XXX error code

Note

Uses bare components rather than an mbedtls_ecp_keypair structure in order to ease use with other structures such as mbedtls_ecdh_context of mbedtls_ecdsa_context.

int mbedtls_ecp_gen_keypair_base	(	mbedtls_ecp_group *	grp,
		const mbedtls_ecp_point *	G,
		mbedtls_mpi *	d,
		mbedtls_ecp_point *	Q,
		int(*)(void *, unsigned char *, size_t)	f_rng,
		void *	p_rng
	)

Generate a keypair with configurable base point.

Parameters

grp	ECP group
G	Chosen base point
d	Destination MPI (secret part)
Q	Destination point (public part)
f_rng	RNG function
p_rng	RNG parameter

Returns

0 if successful, or a MBEDTLS_ERR_ECP_XXX or MBEDTLS_MPI_XXX error code

Note

Uses bare components rather than an mbedtls_ecp_keypair structure in order to ease use with other structures such as mbedtls_ecdh_context of mbedtls_ecdsa_context.

int mbedtls_ecp_group_copy	(	mbedtls_ecp_group *	dst,
		const mbedtls_ecp_group *	src
	)

Copy the contents of a group object.

Parameters

dst	Destination group
src	Source group

Returns

0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed

void mbedtls_ecp_group_free

(

mbedtls_ecp_group *

grp

)

Free the components of an ECP group.

void mbedtls_ecp_group_init

(

mbedtls_ecp_group *

grp

)

Initialize a group (to something meaningless)

int mbedtls_ecp_group_load	(	mbedtls_ecp_group *	grp,
		mbedtls_ecp_group_id	index
	)

Set a group using well-known domain parameters.

Parameters

grp	Destination group
index	Index in the list of well-known domain parameters

Returns

0 if successful, MBEDTLS_ERR_MPI_XXX if initialization failed MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE for unkownn groups

Note

Index should be a value of RFC 4492's enum NamedCurve, usually in the form of a MBEDTLS_ECP_DP_XXX macro.

const mbedtls_ecp_group_id* mbedtls_ecp_grp_id_list

(

void

)

Get the list of supported curves in order of preferrence (grp_id only)

Returns

A statically allocated array, terminated with MBEDTLS_ECP_DP_NONE.

int mbedtls_ecp_is_zero

(

mbedtls_ecp_point *

pt

)

Tell if a point is zero.

Parameters

pt	Point to test

Returns

1 if point is zero, 0 otherwise

void mbedtls_ecp_keypair_free

(

mbedtls_ecp_keypair *

key

)

Free the components of a key pair.

void mbedtls_ecp_keypair_init

(

mbedtls_ecp_keypair *

key

)

Initialize a key pair (as an invalid one)

int mbedtls_ecp_mul	(	mbedtls_ecp_group *	grp,
		mbedtls_ecp_point *	R,
		const mbedtls_mpi *	m,
		const mbedtls_ecp_point *	P,
		int(*)(void *, unsigned char *, size_t)	f_rng,
		void *	p_rng
	)

Multiplication by an integer: R = m * P (Not thread-safe to use same group in multiple threads)

Note

In order to prevent timing attacks, this function executes the exact same sequence of (base field) operations for any valid m. It avoids any if-branch or array index depending on the value of m.

If f_rng is not NULL, it is used to randomize intermediate results in order to prevent potential timing attacks targeting these results. It is recommended to always provide a non-NULL f_rng (the overhead is negligible).

Parameters

grp	ECP group
R	Destination point
m	Integer by which to multiply
P	Point to multiply
f_rng	RNG function (see notes)
p_rng	RNG parameter

Returns

0 if successful, MBEDTLS_ERR_ECP_INVALID_KEY if m is not a valid privkey or P is not a valid pubkey, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed

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
	)

Multiplication and addition of two points by integers: R = m * P + n * Q (Not thread-safe to use same group in multiple threads)

Note

In contrast to mbedtls_ecp_mul(), this function does not guarantee a constant execution flow and timing.

Parameters

grp	ECP group
R	Destination point
m	Integer by which to multiply P
P	Point to multiply by m
n	Integer by which to multiply Q
Q	Point to be multiplied by n

Returns

0 if successful, MBEDTLS_ERR_ECP_INVALID_KEY if m or n is not a valid privkey or P or Q is not a valid pubkey, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed

int mbedtls_ecp_point_cmp	(	const mbedtls_ecp_point *	P,
		const mbedtls_ecp_point *	Q
	)

Compare two points.

Note

This assumes the points are normalized. Otherwise, they may compare as "not equal" even if they are.

Parameters

P	First point to compare
Q	Second point to compare

Returns

0 if the points are equal, MBEDTLS_ERR_ECP_BAD_INPUT_DATA otherwise

void mbedtls_ecp_point_free

(

mbedtls_ecp_point *

pt

)

Free the components of a point.

void mbedtls_ecp_point_init

(

mbedtls_ecp_point *

pt

)

Initialize a point (as zero)

int mbedtls_ecp_point_read_binary	(	const mbedtls_ecp_group *	grp,
		mbedtls_ecp_point *	P,
		const unsigned char *	buf,
		size_t	ilen
	)

Import a point from unsigned binary data.

Parameters

grp	Group to which the point should belong
P	Point to import
buf	Input buffer
ilen	Actual length of input

Returns

0 if successful, MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed, MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the point format is not implemented.

Note

This function does NOT check that the point actually belongs to the given group, see mbedtls_ecp_check_pubkey() for that.

int mbedtls_ecp_point_read_string	(	mbedtls_ecp_point *	P,
		int	radix,
		const char *	x,
		const char *	y
	)

Import a non-zero point from two ASCII strings.

Parameters

P	Destination point
radix	Input numeric base
x	First affine coordinate as a null-terminated string
y	Second affine coordinate as a null-terminated string

Returns

0 if successful, or a MBEDTLS_ERR_MPI_XXX error code

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
	)

Export a point into unsigned binary data.

Parameters

grp	Group to which the point should belong
P	Point to export
format	Point format, should be a MBEDTLS_ECP_PF_XXX macro
olen	Length of the actual output
buf	Output buffer
buflen	Length of the output buffer

Returns

0 if successful, or MBEDTLS_ERR_ECP_BAD_INPUT_DATA or MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL

int mbedtls_ecp_set_zero

(

mbedtls_ecp_point *

pt

)

Set a point to zero.

Parameters

pt	Destination point

Returns

0 if successful, MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed

int mbedtls_ecp_tls_read_group	(	mbedtls_ecp_group *	grp,
		const unsigned char **	buf,
		size_t	len
	)

Set a group from a TLS ECParameters record.

Parameters

grp	Destination group
buf	&(Start of input buffer)
len	Buffer length

Note

buf is updated to point right after ECParameters on exit

Returns

0 if successful, MBEDTLS_ERR_MPI_XXX if initialization failed MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid

int mbedtls_ecp_tls_read_point	(	const mbedtls_ecp_group *	grp,
		mbedtls_ecp_point *	pt,
		const unsigned char **	buf,
		size_t	len
	)

Import a point from a TLS ECPoint record.

Parameters

grp	ECP group used
pt	Destination point
buf	$(Start of input buffer)
len	Buffer length

Note

buf is updated to point right after the ECPoint on exit

Returns

0 if successful, MBEDTLS_ERR_MPI_XXX if initialization failed MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid

int mbedtls_ecp_tls_write_group	(	const mbedtls_ecp_group *	grp,
		size_t *	olen,
		unsigned char *	buf,
		size_t	blen
	)

Write the TLS ECParameters record for a group.

Parameters

grp	ECP group used
olen	Number of bytes actually written
buf	Buffer to write to
blen	Buffer length

Returns

0 if successful, or MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL

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
	)

Export a point as a TLS ECPoint record.

Parameters

grp	ECP group used
pt	Point to export
format	Export format
olen	length of data written
buf	Buffer to write to
blen	Buffer length

Returns

0 if successful, or MBEDTLS_ERR_ECP_BAD_INPUT_DATA or MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL