HMAC_DRBG (NIST SP 800-90A) More...

Data Structures
struct	hmac_drbg_context
	HMAC_DRBG context. More...
Functions
int	hmac_drbg_init (hmac_drbg_context ctx, const md_info_t md_info, int(f_entropy)(void , unsigned char , size_t), void p_entropy, const unsigned char *custom, size_t len)
	HMAC_DRBG initialisation.
int	hmac_drbg_init_buf (hmac_drbg_context ctx, const md_info_t md_info, const unsigned char *data, size_t data_len)
	Initilisation of simpified HMAC_DRBG (never reseeds).
void	hmac_drbg_set_prediction_resistance (hmac_drbg_context *ctx, int resistance)
	Enable / disable prediction resistance (Default: Off)
void	hmac_drbg_set_entropy_len (hmac_drbg_context *ctx, size_t len)
	Set the amount of entropy grabbed on each reseed (Default: given by the security strength, which depends on the hash used, see `hmac_drbg_init()` )
void	hmac_drbg_set_reseed_interval (hmac_drbg_context *ctx, int interval)
	Set the reseed interval (Default: POLARSSL_HMAC_DRBG_RESEED_INTERVAL)
void	hmac_drbg_update (hmac_drbg_context ctx, const unsigned char additional, size_t add_len)
	HMAC_DRBG update state.
int	hmac_drbg_reseed (hmac_drbg_context ctx, const unsigned char additional, size_t len)
	HMAC_DRBG reseeding (extracts data from entropy source)
int	hmac_drbg_random_with_add (void p_rng, unsigned char output, size_t output_len, const unsigned char *additional, size_t add_len)
	HMAC_DRBG generate random with additional update input.
int	hmac_drbg_random (void p_rng, unsigned char output, size_t out_len)
	HMAC_DRBG generate random.
void	hmac_drbg_free (hmac_drbg_context *ctx)
	Free an HMAC_DRBG context.
int	hmac_drbg_write_seed_file (hmac_drbg_context ctx, const char path)
	Write a seed file.
int	hmac_drbg_update_seed_file (hmac_drbg_context ctx, const char path)
	Read and update a seed file.
int	hmac_drbg_self_test (int verbose)
	Checkup routine.

Detailed Description

HMAC_DRBG (NIST SP 800-90A)

This file is part of mbed TLS (https://tls.mbed.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 hmac_drbg.h.

Function Documentation

void hmac_drbg_free ( hmac_drbg_context * ctx )

Free an HMAC_DRBG context.

Parameters:

ctx	HMAC_DRBG context to free.

Definition at line 312 of file hmac_drbg.c.

int hmac_drbg_init	(	hmac_drbg_context *	ctx,
		const md_info_t *	md_info,
		int()(void , unsigned char *, size_t)	f_entropy,
		void *	p_entropy,
		const unsigned char *	custom,
		size_t	len
	)

HMAC_DRBG initialisation.

Parameters:

ctx	HMAC_DRBG context to be initialised
md_info	MD algorithm to use for HMAC_DRBG
f_entropy	Entropy callback (p_entropy, buffer to fill, buffer length)
p_entropy	Entropy context
custom	Personalization data (Device specific identifiers) (Can be NULL)
len	Length of personalization data

Note:: The "security strength" as defined by NIST is set to: 128 bits if md_alg is SHA-1, 192 bits if md_alg is SHA-224, 256 bits if md_alg is SHA-256 or higher. Note that SHA-256 is just as efficient as SHA-224.

Returns:: 0 if successful, or POLARSSL_ERR_MD_BAD_INPUT_DATA, or POLARSSL_ERR_MD_ALLOC_FAILED, or POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED.

Definition at line 160 of file hmac_drbg.c.

int hmac_drbg_init_buf	(	hmac_drbg_context *	ctx,
		const md_info_t *	md_info,
		const unsigned char *	data,
		size_t	data_len
	)

Initilisation of simpified HMAC_DRBG (never reseeds).

(For use with deterministic ECDSA.)

Parameters:

ctx	HMAC_DRBG context to be initialised
md_info	MD algorithm to use for HMAC_DRBG
data	Concatenation of entropy string and additional data
data_len	Length of data in bytes

Returns:: 0 if successful, or POLARSSL_ERR_MD_BAD_INPUT_DATA, or POLARSSL_ERR_MD_ALLOC_FAILED.

Definition at line 90 of file hmac_drbg.c.

int hmac_drbg_random	(	void *	p_rng,
		unsigned char *	output,
		size_t	out_len
	)

HMAC_DRBG generate random.

Note: Automatically reseeds if reseed_counter is reached or PR is enabled.

Parameters:

p_rng	HMAC_DRBG context
output	Buffer to fill
out_len	Length of the buffer

Returns:: 0 if successful, or POLARSSL_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED, or POLARSSL_ERR_HMAC_DRBG_REQUEST_TOO_BIG

Definition at line 304 of file hmac_drbg.c.

int hmac_drbg_random_with_add	(	void *	p_rng,
		unsigned char *	output,
		size_t	output_len,
		const unsigned char *	additional,
		size_t	add_len
	)

HMAC_DRBG generate random with additional update input.

Note: Automatically reseeds if reseed_counter is reached or PR is enabled.

Parameters:

p_rng	HMAC_DRBG context
output	Buffer to fill
output_len	Length of the buffer
additional	Additional data to update with (can be NULL)
add_len	Length of additional data (can be 0)

Returns:: 0 if successful, or POLARSSL_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED, or POLARSSL_ERR_HMAC_DRBG_REQUEST_TOO_BIG, or POLARSSL_ERR_HMAC_DRBG_INPUT_TOO_BIG.

Definition at line 244 of file hmac_drbg.c.

int hmac_drbg_reseed	(	hmac_drbg_context *	ctx,
		const unsigned char *	additional,
		size_t	len
	)

HMAC_DRBG reseeding (extracts data from entropy source)

Parameters:

ctx	HMAC_DRBG context
additional	Additional data to add to state (Can be NULL)
len	Length of additional data

Returns:: 0 if successful, or POLARSSL_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED

Definition at line 119 of file hmac_drbg.c.

int hmac_drbg_self_test ( int verbose )

Checkup routine.

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

Definition at line 450 of file hmac_drbg.c.

void hmac_drbg_set_entropy_len	(	hmac_drbg_context *	ctx,
		size_t	len
	)

Set the amount of entropy grabbed on each reseed (Default: given by the security strength, which depends on the hash used, see hmac_drbg_init() )

Parameters:

ctx	HMAC_DRBG context
len	Amount of entropy to grab, in bytes

Definition at line 227 of file hmac_drbg.c.

void hmac_drbg_set_prediction_resistance	(	hmac_drbg_context *	ctx,
		int	resistance
	)

Enable / disable prediction resistance (Default: Off)

Note: If enabled, entropy is used for ctx->entropy_len before each call! Only use this if you have ample supply of good entropy!

Parameters:

ctx	HMAC_DRBG context
resistance	POLARSSL_HMAC_DRBG_PR_ON or POLARSSL_HMAC_DRBG_PR_OFF

Definition at line 218 of file hmac_drbg.c.

void hmac_drbg_set_reseed_interval	(	hmac_drbg_context *	ctx,
		int	interval
	)

Set the reseed interval (Default: POLARSSL_HMAC_DRBG_RESEED_INTERVAL)

Parameters:

ctx	HMAC_DRBG context
interval	Reseed interval

Definition at line 235 of file hmac_drbg.c.

void hmac_drbg_update	(	hmac_drbg_context *	ctx,
		const unsigned char *	additional,
		size_t	add_len
	)

HMAC_DRBG update state.

Parameters:

ctx	HMAC_DRBG context
additional	Additional data to update state with, or NULL
add_len	Length of additional data, or 0

Note:: Additional data is optional, pass NULL and 0 as second third argument if no additional data is being used.

Definition at line 62 of file hmac_drbg.c.

int hmac_drbg_update_seed_file	(	hmac_drbg_context *	ctx,
		const char *	path
	)

Read and update a seed file.

Seed is added to this instance

Parameters:

ctx	HMAC_DRBG context
path	Name of the file

Returns:: 0 if successful, 1 on file error, POLARSSL_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED or POLARSSL_ERR_HMAC_DRBG_INPUT_TOO_BIG

Definition at line 348 of file hmac_drbg.c.

int hmac_drbg_write_seed_file	(	hmac_drbg_context *	ctx,
		const char *	path
	)

Write a seed file.

Parameters:

ctx	HMAC_DRBG context
path	Name of the file

Returns:: 0 if successful, 1 on file error, or POLARSSL_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED

Definition at line 323 of file hmac_drbg.c.

Type:	Library
Created:	11 Jun 2015
Imports:	10
Forks:	0
Commits:	1
Dependents:	2
Dependencies:	0
Followers:	1

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hmac_drbg.h File Reference

Data Structures

Functions

Detailed Description

Function Documentation

Repository toolbox

Repository details

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