ecdsa.h File Reference

Detailed Description

Elliptic curve DSA.

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 ecdsa.h.

#include "ecp.h"
#include "md.h"

Include dependency graph for ecdsa.h:

Go to the source code of this file.

Macros
#define	MBEDTLS_ECDSA_MAX_LEN   ( 3 + 2 * ( 3 + MBEDTLS_ECP_MAX_BYTES ) )
	Maximum size of an ECDSA signature in bytes. More...

Typedefs
typedef mbedtls_ecp_keypair	mbedtls_ecdsa_context
	ECDSA context structure. More...

Functions
int	mbedtls_ecdsa_sign (mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s, const mbedtls_mpi *d, const unsigned char *buf, size_t blen, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
	Compute ECDSA signature of a previously hashed message. More...
int	mbedtls_ecdsa_verify (mbedtls_ecp_group *grp, const unsigned char *buf, size_t blen, const mbedtls_ecp_point *Q, const mbedtls_mpi *r, const mbedtls_mpi *s)
	Verify ECDSA signature of a previously hashed message. More...
int	mbedtls_ecdsa_write_signature (mbedtls_ecdsa_context *ctx, mbedtls_md_type_t md_alg, const unsigned char *hash, size_t hlen, unsigned char *sig, size_t *slen, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
	Compute ECDSA signature and write it to buffer, serialized as defined in RFC 4492 page 20. More...
int	mbedtls_ecdsa_read_signature (mbedtls_ecdsa_context *ctx, const unsigned char *hash, size_t hlen, const unsigned char *sig, size_t slen)
	Read and verify an ECDSA signature. More...
int	mbedtls_ecdsa_genkey (mbedtls_ecdsa_context *ctx, mbedtls_ecp_group_id gid, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
	Generate an ECDSA keypair on the given curve. More...
int	mbedtls_ecdsa_from_keypair (mbedtls_ecdsa_context *ctx, const mbedtls_ecp_keypair *key)
	Set an ECDSA context from an EC key pair. More...
void	mbedtls_ecdsa_init (mbedtls_ecdsa_context *ctx)
	Initialize context. More...
void	mbedtls_ecdsa_free (mbedtls_ecdsa_context *ctx)
	Free context. More...

Macro Definition Documentation

#define MBEDTLS_ECDSA_MAX_LEN   ( 3 + 2 * ( 3 + MBEDTLS_ECP_MAX_BYTES ) )

Maximum size of an ECDSA signature in bytes.

Definition at line 47 of file ecdsa.h.

Typedef Documentation

typedef mbedtls_ecp_keypair mbedtls_ecdsa_context

ECDSA context structure.

Definition at line 52 of file ecdsa.h.

Function Documentation

void mbedtls_ecdsa_free

(

mbedtls_ecdsa_context *

ctx

)

Free context.

Parameters

ctx	Context to free

int mbedtls_ecdsa_from_keypair	(	mbedtls_ecdsa_context *	ctx,
		const mbedtls_ecp_keypair *	key
	)

Set an ECDSA context from an EC key pair.

Parameters

ctx	ECDSA context to set
key	EC key to use

Returns

0 on success, or a MBEDTLS_ERR_ECP_XXX code.

int mbedtls_ecdsa_genkey	(	mbedtls_ecdsa_context *	ctx,
		mbedtls_ecp_group_id	gid,
		int(*)(void *, unsigned char *, size_t)	f_rng,
		void *	p_rng
	)

Generate an ECDSA keypair on the given curve.

Parameters

ctx	ECDSA context in which the keypair should be stored
gid	Group (elliptic curve) to use. One of the various MBEDTLS_ECP_DP_XXX macros depending on configuration.
f_rng	RNG function
p_rng	RNG parameter

Returns

0 on success, or a MBEDTLS_ERR_ECP_XXX code.

void mbedtls_ecdsa_init

(

mbedtls_ecdsa_context *

ctx

)

Initialize context.

Parameters

ctx	Context to initialize

int mbedtls_ecdsa_read_signature	(	mbedtls_ecdsa_context *	ctx,
		const unsigned char *	hash,
		size_t	hlen,
		const unsigned char *	sig,
		size_t	slen
	)

Read and verify an ECDSA signature.

Parameters

ctx	ECDSA context
hash	Message hash
hlen	Size of hash
sig	Signature to read and verify
slen	Size of sig

Returns

0 if successful, MBEDTLS_ERR_ECP_BAD_INPUT_DATA if signature is invalid, MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH if the signature is valid but its actual length is less than siglen, or a MBEDTLS_ERR_ECP_XXX or MBEDTLS_ERR_MPI_XXX error code

int mbedtls_ecdsa_sign	(	mbedtls_ecp_group *	grp,
		mbedtls_mpi *	r,
		mbedtls_mpi *	s,
		const mbedtls_mpi *	d,
		const unsigned char *	buf,
		size_t	blen,
		int(*)(void *, unsigned char *, size_t)	f_rng,
		void *	p_rng
	)

Compute ECDSA signature of a previously hashed message.

Note

The deterministic version is usually prefered.

Parameters

grp	ECP group
r	First output integer
s	Second output integer
d	Private signing key
buf	Message hash
blen	Length of buf
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_ecdsa_verify	(	mbedtls_ecp_group *	grp,
		const unsigned char *	buf,
		size_t	blen,
		const mbedtls_ecp_point *	Q,
		const mbedtls_mpi *	r,
		const mbedtls_mpi *	s
	)

Verify ECDSA signature of a previously hashed message.

Parameters

grp	ECP group
buf	Message hash
blen	Length of buf
Q	Public key to use for verification
r	First integer of the signature
s	Second integer of the signature

Returns

0 if successful, MBEDTLS_ERR_ECP_BAD_INPUT_DATA if signature is invalid or a MBEDTLS_ERR_ECP_XXX or MBEDTLS_MPI_XXX error code

int mbedtls_ecdsa_write_signature	(	mbedtls_ecdsa_context *	ctx,
		mbedtls_md_type_t	md_alg,
		const unsigned char *	hash,
		size_t	hlen,
		unsigned char *	sig,
		size_t *	slen,
		int(*)(void *, unsigned char *, size_t)	f_rng,
		void *	p_rng
	)

Compute ECDSA signature and write it to buffer, serialized as defined in RFC 4492 page 20.

(Not thread-safe to use same context in multiple threads)

Note

The deterministice version (RFC 6979) is used if MBEDTLS_ECDSA_DETERMINISTIC is defined.

Parameters

ctx	ECDSA context
md_alg	Algorithm that was used to hash the message
hash	Message hash
hlen	Length of hash
sig	Buffer that will hold the signature
slen	Length of the signature written
f_rng	RNG function
p_rng	RNG parameter

Note

The "sig" buffer must be at least as large as twice the size of the curve used, plus 9 (eg. 73 bytes if a 256-bit curve is used). MBEDTLS_ECDSA_MAX_LEN is always safe.

Returns

0 if successful, or a MBEDTLS_ERR_ECP_XXX, MBEDTLS_ERR_MPI_XXX or MBEDTLS_ERR_ASN1_XXX error code