ecdsa.h File Reference

Elliptic curve DSA. More...

#include "ecp.h"

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Data Structures
struct	ecdsa_context
	ECDSA context structure. More...
Functions
int	ecdsa_sign (ecp_group grp, mpi r, mpi s, const 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.
int	ecdsa_verify (ecp_group grp, const unsigned char buf, size_t blen, const ecp_point Q, const mpi r, const mpi *s)
	Verify ECDSA signature of a previously hashed message.
int	ecdsa_write_signature (ecdsa_context ctx, 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.
int	ecdsa_read_signature (ecdsa_context ctx, const unsigned char hash, size_t hlen, const unsigned char *sig, size_t slen)
	Read and verify an ECDSA signature.
int	ecdsa_genkey (ecdsa_context ctx, ecp_group_id gid, int(f_rng)(void , unsigned char , size_t), void *p_rng)
	Generate an ECDSA keypair on the given curve.
int	ecdsa_from_keypair (ecdsa_context ctx, const ecp_keypair key)
	Set an ECDSA context from an EC key pair.
void	ecdsa_init (ecdsa_context *ctx)
	Initialize context.
void	ecdsa_free (ecdsa_context *ctx)
	Free context.
int	ecdsa_self_test (int verbose)
	Checkup routine.

Detailed Description

Elliptic curve DSA.

This file is part of PolarSSL (http://www.polarssl.org) Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

Definition in file ecdsa.h.

Function Documentation

void ecdsa_free ( ecdsa_context * ctx )

Free context.

Parameters:

ctx

Context to free

Definition at line 328 of file ecdsa.c.

References ecdsa_context::d, ecp_group_free(), ecp_point_free(), ecdsa_context::grp, mpi_free(), ecdsa_context::Q, ecdsa_context::r, and ecdsa_context::s.

Referenced by ecdsa_free_wrap(), ecdsa_from_keypair(), eckey_sign_wrap(), and eckey_verify_wrap().

int ecdsa_from_keypair	(	ecdsa_context *	ctx,
		const 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 POLARSSL_ERR_ECP code.

Definition at line 299 of file ecdsa.c.

References ecp_keypair::d, ecdsa_context::d, ecdsa_free(), ecp_copy(), ecp_group_copy(), ecp_keypair::grp, ecdsa_context::grp, mpi_copy(), ecp_keypair::Q, and ecdsa_context::Q.

Referenced by eckey_sign_wrap(), and eckey_verify_wrap().

int ecdsa_genkey	(	ecdsa_context *	ctx,
		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 POLARSSL_ECP_DP_XXX macros depending on configuration.
	f_rng	RNG function
	p_rng	RNG parameter

Returns:: 0 on success, or a POLARSSL_ERR_ECP code.

Definition at line 289 of file ecdsa.c.

References ecdsa_context::d, ecp_gen_keypair(), ecp_use_known_dp(), ecdsa_context::grp, and ecdsa_context::Q.

void ecdsa_init ( ecdsa_context * ctx )

Initialize context.

Parameters:

ctx

Context to initialize

Definition at line 316 of file ecdsa.c.

References ecdsa_context::d, ecp_group_init(), ecp_point_init(), ecdsa_context::grp, mpi_init(), ecdsa_context::Q, ecdsa_context::r, and ecdsa_context::s.

Referenced by ecdsa_alloc_wrap(), eckey_sign_wrap(), and eckey_verify_wrap().

int ecdsa_read_signature	(	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, POLARSSL_ERR_ECP_BAD_INPUT_DATA if signature is invalid or a POLARSSL_ERR_ECP or POLARSSL_ERR_MPI error code

Definition at line 256 of file ecdsa.c.

References ASN1_CONSTRUCTED, asn1_get_mpi(), asn1_get_tag(), ASN1_SEQUENCE, ecdsa_verify(), ecdsa_context::grp, POLARSSL_ERR_ASN1_LENGTH_MISMATCH, POLARSSL_ERR_ECP_BAD_INPUT_DATA, ecdsa_context::Q, ecdsa_context::r, and ecdsa_context::s.

Referenced by ecdsa_verify_wrap().

int ecdsa_self_test ( int verbose )

Checkup routine.

Returns:: 0 if successful, or 1 if the test failed

Definition at line 342 of file ecdsa.c.

int ecdsa_sign	(	ecp_group *	grp,
		mpi *	r,
		mpi *	s,
		const 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.

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 POLARSSL_ERR_ECP_XXX or POLARSSL_MPI_XXX error code

Definition at line 54 of file ecdsa.c.

References derive_mpi(), ecp_gen_keypair(), ecp_point_free(), ecp_point_init(), mpi_add_mpi(), MPI_CHK, mpi_cmp_int(), mpi_free(), mpi_init(), mpi_inv_mod(), mpi_mod_mpi(), mpi_mul_mpi(), ecp_group::N, POLARSSL_ERR_ECP_RANDOM_FAILED, R, and ecp_point::X.

Referenced by ecdsa_write_signature().

int ecdsa_verify	(	ecp_group *	grp,
		const unsigned char *	buf,
		size_t	blen,
		const ecp_point *	Q,
		const mpi *	r,
		const 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, POLARSSL_ERR_ECP_BAD_INPUT_DATA if signature is invalid or a POLARSSL_ERR_ECP_XXX or POLARSSL_MPI_XXX error code

Definition at line 121 of file ecdsa.c.

References derive_mpi(), ecp_add(), ecp_check_pubkey(), ecp_is_zero(), ecp_mul(), ecp_point_free(), ecp_point_init(), ecp_group::G, MPI_CHK, mpi_cmp_int(), mpi_cmp_mpi(), mpi_free(), mpi_init(), mpi_inv_mod(), mpi_mod_mpi(), mpi_mul_mpi(), ecp_group::N, P, POLARSSL_ERR_ECP_VERIFY_FAILED, R, and ecp_point::X.

Referenced by ecdsa_read_signature().

int ecdsa_write_signature	(	ecdsa_context *	ctx,
		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)

Parameters:

	ctx	ECDSA context
	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 7 (eg. 71 bytes if a 256-bit curve is used).

Returns:: 0 if successful, or a POLARSSL_ERR_ECP, POLARSSL_ERR_MPI or POLARSSL_ERR_ASN1 error code

Definition at line 223 of file ecdsa.c.

References ASN1_CHK_ADD, ASN1_CONSTRUCTED, ASN1_SEQUENCE, asn1_write_len(), asn1_write_mpi(), asn1_write_tag(), ecdsa_context::d, ecdsa_sign(), ecdsa_context::grp, MAX_SIG_LEN, ecdsa_context::r, and ecdsa_context::s.

Referenced by ecdsa_sign_wrap().

ecdsa.h File Reference

Data Structures

Functions

Detailed Description

Function Documentation