include/polarssl/ctr_drbg.h - security/mbedtls - Rivoreo Source Code Repositories

 /**
  * \file ctr_drbg.h
  *
  * \brief CTR_DRBG based on AES-256 (NIST SP 800-90)
  *
  *  Copyright (C) 2006-2014, Brainspark B.V.
  *
  *  This file is part of PolarSSL (http://www.polarssl.org)
  *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
  *
  *  All rights reserved.
  *
  *  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.
  */
 #ifndef POLARSSL_CTR_DRBG_H
 #define POLARSSL_CTR_DRBG_H

 #include <string.h>

 #include "aes.h"

 #define POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED        -0x0034  /**< The entropy source failed. */
 #define POLARSSL_ERR_CTR_DRBG_REQUEST_TOO_BIG              -0x0036  /**< Too many random requested in single call. */
 #define POLARSSL_ERR_CTR_DRBG_INPUT_TOO_BIG                -0x0038  /**< Input too large (Entropy + additional). */
 #define POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR                -0x003A  /**< Read/write error in file. */

 #define CTR_DRBG_BLOCKSIZE          16      /**< Block size used by the cipher                  */
 #define CTR_DRBG_KEYSIZE            32      /**< Key size used by the cipher                    */
 #define CTR_DRBG_KEYBITS            ( CTR_DRBG_KEYSIZE * 8 )
 #define CTR_DRBG_SEEDLEN            ( CTR_DRBG_KEYSIZE + CTR_DRBG_BLOCKSIZE )
                                             /**< The seed length (counter + AES key)            */

 /**
  * \name 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.
  * \{
  */

 #if !defined(CTR_DRBG_ENTROPY_LEN)
 #if defined(POLARSSL_SHA512_C) && !defined(POLARSSL_ENTROPY_FORCE_SHA256)
 #define CTR_DRBG_ENTROPY_LEN        48      /**< Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256) */
 #else
 #define CTR_DRBG_ENTROPY_LEN        32      /**< Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256) */
 #endif
 #endif

 #if !defined(CTR_DRBG_RESEED_INTERVAL)
 #define CTR_DRBG_RESEED_INTERVAL    10000   /**< Interval before reseed is performed by default */
 #endif

 #if !defined(CTR_DRBG_MAX_INPUT)
 #define CTR_DRBG_MAX_INPUT          256     /**< Maximum number of additional input bytes */
 #endif

 #if !defined(CTR_DRBG_MAX_REQUEST)
 #define CTR_DRBG_MAX_REQUEST        1024    /**< Maximum number of requested bytes per call */
 #endif

 #if !defined(CTR_DRBG_MAX_SEED_INPUT)
 #define CTR_DRBG_MAX_SEED_INPUT     384     /**< Maximum size of (re)seed buffer */
 #endif

 /* \} name SECTION: Module settings */

 #define CTR_DRBG_PR_OFF             0       /**< No prediction resistance       */
 #define CTR_DRBG_PR_ON              1       /**< Prediction resistance enabled  */

 #ifdef __cplusplus
 extern "C" {
 #endif

 /**
  * \brief          CTR_DRBG context structure
  */
 typedef struct
 {
     unsigned char counter[16];  /*!<  counter (V)       */
     int reseed_counter;         /*!<  reseed counter    */
     int prediction_resistance;  /*!<  enable prediction resistance (Automatic
                                       reseed before every random generation)  */
     size_t entropy_len;         /*!<  amount of entropy grabbed on each
                                       (re)seed          */
     int reseed_interval;        /*!<  reseed interval   */

     aes_context aes_ctx;        /*!<  AES context       */

     /*
      * Callbacks (Entropy)
      */
     int (*f_entropy)(void *, unsigned char *, size_t);

     void *p_entropy;            /*!<  context for the entropy function */
 }
 ctr_drbg_context;

 /**
  * \brief               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.
  *
  * \param ctx           CTR_DRBG context to be initialized
  * \param f_entropy     Entropy callback (p_entropy, buffer to fill, buffer
  *                      length)
  * \param p_entropy     Entropy context
  * \param custom        Personalization data (Device specific identifiers)
  *                      (Can be NULL)
  * \param len           Length of personalization data
  *
  * \return              0 if successful, or
  *                      POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED
  */
 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 );

 /**
  * \brief               Clear CTR_CRBG context data
  *
  * \param ctx           CTR_DRBG context to clear
  */
 void ctr_drbg_free( ctr_drbg_context *ctx );

 /**
  * \brief               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!
  *
  * \param ctx           CTR_DRBG context
  * \param resistance    CTR_DRBG_PR_ON or CTR_DRBG_PR_OFF
  */
 void ctr_drbg_set_prediction_resistance( ctr_drbg_context *ctx,
                                          int resistance );

 /**
  * \brief               Set the amount of entropy grabbed on each (re)seed
  *                      (Default: CTR_DRBG_ENTROPY_LEN)
  *
  * \param ctx           CTR_DRBG context
  * \param len           Amount of entropy to grab
  */
 void ctr_drbg_set_entropy_len( ctr_drbg_context *ctx,
                                size_t len );

 /**
  * \brief               Set the reseed interval
  *                      (Default: CTR_DRBG_RESEED_INTERVAL)
  *
  * \param ctx           CTR_DRBG context
  * \param interval      Reseed interval
  */
 void ctr_drbg_set_reseed_interval( ctr_drbg_context *ctx,
                                    int interval );

 /**
  * \brief               CTR_DRBG reseeding (extracts data from entropy source)
  *
  * \param ctx           CTR_DRBG context
  * \param additional    Additional data to add to state (Can be NULL)
  * \param len           Length of additional data
  *
  * \return              0 if successful, or
  *                      POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED
  */
 int ctr_drbg_reseed( ctr_drbg_context *ctx,
                      const unsigned char *additional, size_t len );

 /**
  * \brief               CTR_DRBG update state
  *
  * \param ctx           CTR_DRBG context
  * \param additional    Additional data to update state with
  * \param add_len       Length of additional data
  */
 void ctr_drbg_update( ctr_drbg_context *ctx,
                       const unsigned char *additional, size_t add_len );

 /**
  * \brief               CTR_DRBG generate random with additional update input
  *
  * Note: Automatically reseeds if reseed_counter is reached.
  *
  * \param p_rng         CTR_DRBG context
  * \param output        Buffer to fill
  * \param output_len    Length of the buffer
  * \param additional    Additional data to update with (Can be NULL)
  * \param add_len       Length of additional data
  *
  * \return              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 );

 /**
  * \brief               CTR_DRBG generate random
  *
  * Note: Automatically reseeds if reseed_counter is reached.
  *
  * \param p_rng         CTR_DRBG context
  * \param output        Buffer to fill
  * \param output_len    Length of the buffer
  *
  * \return              0 if successful, or
  *                      POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED, or
  *                      POLARSSL_ERR_CTR_DRBG_REQUEST_TOO_BIG
  */
 int ctr_drbg_random( void *p_rng,
                      unsigned char *output, size_t output_len );

 #if defined(POLARSSL_FS_IO)
 /**
  * \brief               Write a seed file
  *
  * \param ctx           CTR_DRBG context
  * \param path          Name of the file
  *
  * \return              0 if successful,
  *                      POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR on file error, or
  *                      POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED
  */
 int ctr_drbg_write_seed_file( ctr_drbg_context *ctx, const char *path );

 /**
  * \brief               Read and update a seed file. Seed is added to this
  *                      instance
  *
  * \param ctx           CTR_DRBG context
  * \param path          Name of the file
  *
  * \return              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_update_seed_file( ctr_drbg_context *ctx, const char *path );
 #endif /* POLARSSL_FS_IO */

 /**
  * \brief               Checkup routine
  *
  * \return              0 if successful, or 1 if the test failed
  */
 int ctr_drbg_self_test( int verbose );

 /* Internal functions (do not call directly) */
 int ctr_drbg_init_entropy_len( ctr_drbg_context *,
                                int (*)(void *, unsigned char *, size_t), void *,
                                const unsigned char *, size_t, size_t );

 #ifdef __cplusplus
 }
 #endif

 #endif /* ctr_drbg.h */
	/**
	* \file ctr_drbg.h
	*
	* \brief CTR_DRBG based on AES-256 (NIST SP 800-90)
	*
	* Copyright (C) 2006-2014, Brainspark B.V.
	*
	* This file is part of PolarSSL (http://www.polarssl.org)
	* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
	*
	* All rights reserved.
	*
	* 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.
	*/
	#ifndef POLARSSL_CTR_DRBG_H
	#define POLARSSL_CTR_DRBG_H

	#include <string.h>

	#include "aes.h"

	#define POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED -0x0034 /*< The entropy source failed. /
	#define POLARSSL_ERR_CTR_DRBG_REQUEST_TOO_BIG -0x0036 /*< Too many random requested in single call. /
	#define POLARSSL_ERR_CTR_DRBG_INPUT_TOO_BIG -0x0038 /*< Input too large (Entropy + additional). /
	#define POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR -0x003A /*< Read/write error in file. /

	#define CTR_DRBG_BLOCKSIZE 16 /*< Block size used by the cipher /
	#define CTR_DRBG_KEYSIZE 32 /*< Key size used by the cipher /
	#define CTR_DRBG_KEYBITS ( CTR_DRBG_KEYSIZE * 8 )
	#define CTR_DRBG_SEEDLEN ( CTR_DRBG_KEYSIZE + CTR_DRBG_BLOCKSIZE )
	/*< The seed length (counter + AES key) /

	/**
	* \name 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.
	* \{
	*/

	#if !defined(CTR_DRBG_ENTROPY_LEN)
	#if defined(POLARSSL_SHA512_C) && !defined(POLARSSL_ENTROPY_FORCE_SHA256)
	#define CTR_DRBG_ENTROPY_LEN 48 /*< Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256) /
	#else
	#define CTR_DRBG_ENTROPY_LEN 32 /*< Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256) /
	#endif
	#endif

	#if !defined(CTR_DRBG_RESEED_INTERVAL)
	#define CTR_DRBG_RESEED_INTERVAL 10000 /*< Interval before reseed is performed by default /
	#endif

	#if !defined(CTR_DRBG_MAX_INPUT)
	#define CTR_DRBG_MAX_INPUT 256 /*< Maximum number of additional input bytes /
	#endif

	#if !defined(CTR_DRBG_MAX_REQUEST)
	#define CTR_DRBG_MAX_REQUEST 1024 /*< Maximum number of requested bytes per call /
	#endif

	#if !defined(CTR_DRBG_MAX_SEED_INPUT)
	#define CTR_DRBG_MAX_SEED_INPUT 384 /*< Maximum size of (re)seed buffer /
	#endif

	/* \} name SECTION: Module settings */

	#define CTR_DRBG_PR_OFF 0 /*< No prediction resistance /
	#define CTR_DRBG_PR_ON 1 /*< Prediction resistance enabled /

	#ifdef __cplusplus
	extern "C" {
	#endif

	/**
	* \brief CTR_DRBG context structure
	*/
	typedef struct
	{
	unsigned char counter[16]; /!< counter (V) /
	int reseed_counter; /!< reseed counter /
	int prediction_resistance; /*!< enable prediction resistance (Automatic
	reseed before every random generation) */
	size_t entropy_len; /*!< amount of entropy grabbed on each
	(re)seed */
	int reseed_interval; /!< reseed interval /

	aes_context aes_ctx; /!< AES context /

	/*
	* Callbacks (Entropy)
	*/
	int (f_entropy)(void , unsigned char *, size_t);

	void p_entropy; /!< context for the entropy function */
	}
	ctr_drbg_context;

	/**
	* \brief 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.
	*
	* \param ctx CTR_DRBG context to be initialized
	* \param f_entropy Entropy callback (p_entropy, buffer to fill, buffer
	* length)
	* \param p_entropy Entropy context
	* \param custom Personalization data (Device specific identifiers)
	* (Can be NULL)
	* \param len Length of personalization data
	*
	* \return 0 if successful, or
	* POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED
	*/
	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 );

	/**
	* \brief Clear CTR_CRBG context data
	*
	* \param ctx CTR_DRBG context to clear
	*/
	void ctr_drbg_free( ctr_drbg_context *ctx );

	/**
	* \brief 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!
	*
	* \param ctx CTR_DRBG context
	* \param resistance CTR_DRBG_PR_ON or CTR_DRBG_PR_OFF
	*/
	void ctr_drbg_set_prediction_resistance( ctr_drbg_context *ctx,
	int resistance );

	/**
	* \brief Set the amount of entropy grabbed on each (re)seed
	* (Default: CTR_DRBG_ENTROPY_LEN)
	*
	* \param ctx CTR_DRBG context
	* \param len Amount of entropy to grab
	*/
	void ctr_drbg_set_entropy_len( ctr_drbg_context *ctx,
	size_t len );

	/**
	* \brief Set the reseed interval
	* (Default: CTR_DRBG_RESEED_INTERVAL)
	*
	* \param ctx CTR_DRBG context
	* \param interval Reseed interval
	*/
	void ctr_drbg_set_reseed_interval( ctr_drbg_context *ctx,
	int interval );

	/**
	* \brief CTR_DRBG reseeding (extracts data from entropy source)
	*
	* \param ctx CTR_DRBG context
	* \param additional Additional data to add to state (Can be NULL)
	* \param len Length of additional data
	*
	* \return 0 if successful, or
	* POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED
	*/
	int ctr_drbg_reseed( ctr_drbg_context *ctx,
	const unsigned char *additional, size_t len );

	/**
	* \brief CTR_DRBG update state
	*
	* \param ctx CTR_DRBG context
	* \param additional Additional data to update state with
	* \param add_len Length of additional data
	*/
	void ctr_drbg_update( ctr_drbg_context *ctx,
	const unsigned char *additional, size_t add_len );

	/**
	* \brief CTR_DRBG generate random with additional update input
	*
	* Note: Automatically reseeds if reseed_counter is reached.
	*
	* \param p_rng CTR_DRBG context
	* \param output Buffer to fill
	* \param output_len Length of the buffer
	* \param additional Additional data to update with (Can be NULL)
	* \param add_len Length of additional data
	*
	* \return 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 );

	/**
	* \brief CTR_DRBG generate random
	*
	* Note: Automatically reseeds if reseed_counter is reached.
	*
	* \param p_rng CTR_DRBG context
	* \param output Buffer to fill
	* \param output_len Length of the buffer
	*
	* \return 0 if successful, or
	* POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED, or
	* POLARSSL_ERR_CTR_DRBG_REQUEST_TOO_BIG
	*/
	int ctr_drbg_random( void *p_rng,
	unsigned char *output, size_t output_len );

	#if defined(POLARSSL_FS_IO)
	/**
	* \brief Write a seed file
	*
	* \param ctx CTR_DRBG context
	* \param path Name of the file
	*
	* \return 0 if successful,
	* POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR on file error, or
	* POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED
	*/
	int ctr_drbg_write_seed_file( ctr_drbg_context ctx, const char path );

	/**
	* \brief Read and update a seed file. Seed is added to this
	* instance
	*
	* \param ctx CTR_DRBG context
	* \param path Name of the file
	*
	* \return 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_update_seed_file( ctr_drbg_context ctx, const char path );
	#endif /* POLARSSL_FS_IO */

	/**
	* \brief Checkup routine
	*
	* \return 0 if successful, or 1 if the test failed
	*/
	int ctr_drbg_self_test( int verbose );

	/* Internal functions (do not call directly) */
	int ctr_drbg_init_entropy_len( ctr_drbg_context *,
	int ()(void , unsigned char , size_t), void ,
	const unsigned char *, size_t, size_t );

	#ifdef __cplusplus
	}
	#endif

	#endif /* ctr_drbg.h */