CTR_DRBG based on AES-256 (NIST SP 800-90) More...

#include <string.h>
#include "aes.h"

Include dependency graph for ctr_drbg.h:

Data Structures
struct	ctr_drbg_context
	CTR_DRBG context structure. More...

Macros
#define	POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED -0x0034
	The entropy source failed. More...

#define	POLARSSL_ERR_CTR_DRBG_REQUEST_TOO_BIG -0x0036
	Too many random requested in single call. More...

#define	POLARSSL_ERR_CTR_DRBG_INPUT_TOO_BIG -0x0038
	Input too large (Entropy + additional). More...

#define	POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR -0x003A
	Read/write error in file. More...

#define	CTR_DRBG_BLOCKSIZE 16
	Block size used by the cipher. More...

#define	CTR_DRBG_KEYSIZE 32
	Key size used by the cipher. More...

#define	CTR_DRBG_KEYBITS ( CTR_DRBG_KEYSIZE * 8 )

#define	CTR_DRBG_SEEDLEN ( CTR_DRBG_KEYSIZE + CTR_DRBG_BLOCKSIZE )
	The seed length (counter + AES key) More...

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

#define	CTR_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	CTR_DRBG_ENTROPY_LEN 48
	Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256) More...

#define	CTR_DRBG_RESEED_INTERVAL 10000
	Interval before reseed is performed by default. More...

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

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

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

Functions
int	ctr_drbg_init (ctr_drbg_context ctx, int(f_entropy)(void , unsigned char , size_t), void p_entropy, const unsigned char custom, size_t len)
	CTR_DRBG initialization. More...

void	ctr_drbg_free (ctr_drbg_context *ctx)
	Clear CTR_CRBG context data. More...

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

void	ctr_drbg_set_entropy_len (ctr_drbg_context *ctx, size_t len)
	Set the amount of entropy grabbed on each (re)seed (Default: CTR_DRBG_ENTROPY_LEN) More...

void	ctr_drbg_set_reseed_interval (ctr_drbg_context *ctx, int interval)
	Set the reseed interval (Default: CTR_DRBG_RESEED_INTERVAL) More...

int	ctr_drbg_reseed (ctr_drbg_context ctx, const unsigned char additional, size_t len)
	CTR_DRBG reseeding (extracts data from entropy source) More...

void	ctr_drbg_update (ctr_drbg_context ctx, const unsigned char additional, size_t add_len)
	CTR_DRBG update state. More...

int	ctr_drbg_random_with_add (void p_rng, unsigned char output, size_t output_len, const unsigned char *additional, size_t add_len)
	CTR_DRBG generate random with additional update input. More...

int	ctr_drbg_random (void p_rng, unsigned char output, size_t output_len)
	CTR_DRBG generate random. More...

int	ctr_drbg_write_seed_file (ctr_drbg_context ctx, const char path)
	Write a seed file. More...

int	ctr_drbg_update_seed_file (ctr_drbg_context ctx, const char path)
	Read and update a seed file. More...

int	ctr_drbg_self_test (int verbose)
	Checkup routine. More...

int	ctr_drbg_init_entropy_len (ctr_drbg_context , int()(void , unsigned char , size_t), void , const unsigned char , size_t, size_t)

Detailed Description

CTR_DRBG based on AES-256 (NIST SP 800-90)

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 ctr_drbg.h.

Macro Definition Documentation

#define CTR_DRBG_BLOCKSIZE 16

Block size used by the cipher.

Definition at line 39 of file ctr_drbg.h.

#define CTR_DRBG_ENTROPY_LEN 48

Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256)

Definition at line 55 of file ctr_drbg.h.

#define CTR_DRBG_KEYBITS ( CTR_DRBG_KEYSIZE * 8 )

Definition at line 41 of file ctr_drbg.h.

#define CTR_DRBG_KEYSIZE 32

Key size used by the cipher.

Definition at line 40 of file ctr_drbg.h.

#define CTR_DRBG_MAX_INPUT 256

Maximum number of additional input bytes.

Definition at line 66 of file ctr_drbg.h.

#define CTR_DRBG_MAX_REQUEST 1024

Maximum number of requested bytes per call.

Definition at line 70 of file ctr_drbg.h.

#define CTR_DRBG_MAX_SEED_INPUT 384

Maximum size of (re)seed buffer.

Definition at line 74 of file ctr_drbg.h.

#define CTR_DRBG_PR_OFF 0

No prediction resistance.

Definition at line 79 of file ctr_drbg.h.

#define CTR_DRBG_PR_ON 1

Prediction resistance enabled.

Definition at line 80 of file ctr_drbg.h.

#define CTR_DRBG_RESEED_INTERVAL 10000

Interval before reseed is performed by default.

Definition at line 62 of file ctr_drbg.h.

#define CTR_DRBG_SEEDLEN ( CTR_DRBG_KEYSIZE + CTR_DRBG_BLOCKSIZE )

The seed length (counter + AES key)

Definition at line 42 of file ctr_drbg.h.

#define POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED -0x0034

The entropy source failed.

Definition at line 34 of file ctr_drbg.h.

#define POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR -0x003A

Read/write error in file.

Definition at line 37 of file ctr_drbg.h.

#define POLARSSL_ERR_CTR_DRBG_INPUT_TOO_BIG -0x0038

Input too large (Entropy + additional).

Definition at line 36 of file ctr_drbg.h.

#define POLARSSL_ERR_CTR_DRBG_REQUEST_TOO_BIG -0x0036

Too many random requested in single call.

Definition at line 35 of file ctr_drbg.h.

Function Documentation

void ctr_drbg_free ( ctr_drbg_context * ctx )

Clear CTR_CRBG context data.

Parameters

ctx	CTR_DRBG context to clear

int ctr_drbg_init	(	ctr_drbg_context *	ctx,
		int()(void , unsigned char *, size_t)	f_entropy,
		void *	p_entropy,
		const unsigned char *	custom,
		size_t	len
	)

CTR_DRBG initialization.

Note: Personalization data can be provided in addition to the more generic entropy source to make this instantiation as unique as possible.

Parameters

ctx	CTR_DRBG context to be initialized
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

Returns: 0 if successful, or POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED

int ctr_drbg_init_entropy_len	(	ctr_drbg_context *	,
		int()(void , unsigned char *, size_t)	,
		void *	,
		const unsigned char *	,
		size_t	,
		size_t
	)

int ctr_drbg_random	(	void *	p_rng,
		unsigned char *	output,
		size_t	output_len
	)

CTR_DRBG generate random.

Note: Automatically reseeds if reseed_counter is reached.

Parameters

p_rng	CTR_DRBG context
output	Buffer to fill
output_len	Length of the buffer

Returns: 0 if successful, or POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED, or POLARSSL_ERR_CTR_DRBG_REQUEST_TOO_BIG

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

CTR_DRBG generate random with additional update input.

Note: Automatically reseeds if reseed_counter is reached.

Parameters

p_rng	CTR_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

Returns: 0 if successful, or POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED, or POLARSSL_ERR_CTR_DRBG_REQUEST_TOO_BIG

int ctr_drbg_reseed	(	ctr_drbg_context *	ctx,
		const unsigned char *	additional,
		size_t	len
	)

CTR_DRBG reseeding (extracts data from entropy source)

Parameters

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

Returns: 0 if successful, or POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED

int ctr_drbg_self_test ( int verbose )

Checkup routine.

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

void ctr_drbg_set_entropy_len	(	ctr_drbg_context *	ctx,
		size_t	len
	)

Set the amount of entropy grabbed on each (re)seed (Default: CTR_DRBG_ENTROPY_LEN)

Parameters

ctx	CTR_DRBG context
len	Amount of entropy to grab

void ctr_drbg_set_prediction_resistance	(	ctr_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	CTR_DRBG context
resistance	CTR_DRBG_PR_ON or CTR_DRBG_PR_OFF

void ctr_drbg_set_reseed_interval	(	ctr_drbg_context *	ctx,
		int	interval
	)

Set the reseed interval (Default: CTR_DRBG_RESEED_INTERVAL)

Parameters

ctx	CTR_DRBG context
interval	Reseed interval

void ctr_drbg_update	(	ctr_drbg_context *	ctx,
		const unsigned char *	additional,
		size_t	add_len
	)

CTR_DRBG update state.

Parameters

ctx	CTR_DRBG context
additional	Additional data to update state with
add_len	Length of additional data

int ctr_drbg_update_seed_file	(	ctr_drbg_context *	ctx,
		const char *	path
	)

Read and update a seed file.

Seed is added to this instance

Parameters

ctx	CTR_DRBG context
path	Name of the file

Returns: 0 if successful, POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR on file error, POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED or POLARSSL_ERR_CTR_DRBG_INPUT_TOO_BIG

int ctr_drbg_write_seed_file	(	ctr_drbg_context *	ctx,
		const char *	path
	)

Write a seed file.

Parameters

ctx	CTR_DRBG context
path	Name of the file

Returns: 0 if successful, POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR on file error, or POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED

Data Structures

Macros

Functions

Detailed Description

Macro Definition Documentation

Function Documentation