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

#include "md.h"

Include dependency graph for hmac_drbg.h:

Data Structures
struct	hmac_drbg_context
	HMAC_DRBG context. More...

Macros
#define	POLARSSL_ERR_HMAC_DRBG_REQUEST_TOO_BIG -0x0003
	Too many random requested in single call. More...

#define	POLARSSL_ERR_HMAC_DRBG_INPUT_TOO_BIG -0x0005
	Input too large (Entropy + additional). More...

#define	POLARSSL_ERR_HMAC_DRBG_FILE_IO_ERROR -0x0007
	Read/write error in file. More...

#define	POLARSSL_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED -0x0009
	The entropy source failed. More...

#define	POLARSSL_HMAC_DRBG_PR_OFF 0
	No prediction resistance. More...

#define	POLARSSL_HMAC_DRBG_PR_ON 1
	Prediction resistance enabled. 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	POLARSSL_HMAC_DRBG_RESEED_INTERVAL 10000
	Interval before reseed is performed by default. More...

#define	POLARSSL_HMAC_DRBG_MAX_INPUT 256
	Maximum number of additional input bytes. More...

#define	POLARSSL_HMAC_DRBG_MAX_REQUEST 1024
	Maximum number of requested bytes per call. More...

#define	POLARSSL_HMAC_DRBG_MAX_SEED_INPUT 384
	Maximum size of (re)seed buffer. 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. More...

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). More...

void	hmac_drbg_set_prediction_resistance (hmac_drbg_context *ctx, int resistance)
	Enable / disable prediction resistance (Default: Off) More...

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()` ) More...

void	hmac_drbg_set_reseed_interval (hmac_drbg_context *ctx, int interval)
	Set the reseed interval (Default: POLARSSL_HMAC_DRBG_RESEED_INTERVAL) More...

void	hmac_drbg_update (hmac_drbg_context ctx, const unsigned char additional, size_t add_len)
	HMAC_DRBG update state. More...

int	hmac_drbg_reseed (hmac_drbg_context ctx, const unsigned char additional, size_t len)
	HMAC_DRBG reseeding (extracts data from entropy source) More...

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. More...

int	hmac_drbg_random (void p_rng, unsigned char output, size_t out_len)
	HMAC_DRBG generate random. More...

void	hmac_drbg_free (hmac_drbg_context *ctx)
	Free an HMAC_DRBG context. More...

Detailed Description

HMAC_DRBG (NIST SP 800-90A)

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 hmac_drbg.h.

Macro Definition Documentation

#define POLARSSL_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED -0x0009

The entropy source failed.

Definition at line 38 of file hmac_drbg.h.

#define POLARSSL_ERR_HMAC_DRBG_FILE_IO_ERROR -0x0007

Read/write error in file.

Definition at line 37 of file hmac_drbg.h.

#define POLARSSL_ERR_HMAC_DRBG_INPUT_TOO_BIG -0x0005

Input too large (Entropy + additional).

Definition at line 36 of file hmac_drbg.h.

#define POLARSSL_ERR_HMAC_DRBG_REQUEST_TOO_BIG -0x0003

Too many random requested in single call.

Definition at line 35 of file hmac_drbg.h.

#define POLARSSL_HMAC_DRBG_MAX_INPUT 256

Maximum number of additional input bytes.

Definition at line 53 of file hmac_drbg.h.

#define POLARSSL_HMAC_DRBG_MAX_REQUEST 1024

Maximum number of requested bytes per call.

Definition at line 57 of file hmac_drbg.h.

#define POLARSSL_HMAC_DRBG_MAX_SEED_INPUT 384

Maximum size of (re)seed buffer.

Definition at line 61 of file hmac_drbg.h.

#define POLARSSL_HMAC_DRBG_PR_OFF 0

No prediction resistance.

Definition at line 66 of file hmac_drbg.h.

#define POLARSSL_HMAC_DRBG_PR_ON 1

Prediction resistance enabled.

Definition at line 67 of file hmac_drbg.h.

#define POLARSSL_HMAC_DRBG_RESEED_INTERVAL 10000

Interval before reseed is performed by default.

Definition at line 49 of 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.

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.

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.

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

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.

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

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

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

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

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.

Data Structures

Macros

Functions

Detailed Description

Macro Definition Documentation

Function Documentation