Merge remote-tracking branch 'origin/pr/2860' into mbedtls-2.16

* origin/pr/2860: (26 commits)
  config.pl full: exclude MBEDTLS_CTR_DRBG_USE_128_BIT_KEY
  mbedtls_hmac_drbg_set_entropy_len() only matters when reseeding
  mbedtls_ctr_drbg_set_entropy_len() only matters when reseeding
  mbedtls_ctr_drbg_seed: correct maximum for len
  Add a note about CTR_DRBG security strength to config.h
  Move MBEDTLS_CTR_DRBG_USE_128_BIT_KEY to the correct section
  CTR_DRBG: more consistent formatting and wording
  CTR_DRBG documentation: further wording improvements
  CTR_DRBG: Improve the explanation of security strength
  CTR_DRBG: make it easier to understand the security strength
  HMAC_DRBG: note that the initial seeding grabs entropy for the nonce
  Use standard terminology to describe the personalization string
  Do note that xxx_drbg_random functions reseed with PR enabled
  Consistently use \c NULL and \c 0
  Also mention HMAC_DRBG in the changelog entry
  HMAC_DRBG: improve the documentation of the entropy length
  HMAC_DRBG documentation improvements clarifications
  More CTR_DRBG documentation improvements and clarifications
  Fix wording
  Remove warning that the previous expanded discussion has obsoleted
  ...
This commit is contained in:
Jaeden Amero 2019-10-18 14:22:42 +01:00
commit 069fb0e09a
7 changed files with 388 additions and 152 deletions

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@ -10,6 +10,9 @@ Bugfix
Changes
* Add unit tests for AES-GCM when called through mbedtls_cipher_auth_xxx()
from the cipher abstraction layer. Fixes #2198.
* Clarify how the interface of the CTR_DRBG and HMAC modules relates to
NIST SP 800-90A. In particular CTR_DRBG requires an explicit nonce
to achieve a 256-bit strength if MBEDTLS_ENTROPY_FORCE_SHA256 is set.
= mbed TLS 2.16.3 branch released 2019-09-06

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@ -689,6 +689,13 @@
#define MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN
#define MBEDTLS_CIPHER_PADDING_ZEROS
/** \def MBEDTLS_CTR_DRBG_USE_128_BIT_KEY
*
* Uncomment this macro to use a 128-bit key in the CTR_DRBG module.
* By default, CTR_DRBG uses a 256-bit key.
*/
//#define MBEDTLS_CTR_DRBG_USE_128_BIT_KEY
/**
* \def MBEDTLS_ENABLE_WEAK_CIPHERSUITES
*
@ -2149,7 +2156,11 @@
*
* Enable the CTR_DRBG AES-based random generator.
* The CTR_DRBG generator uses AES-256 by default.
* To use AES-128 instead, enable MBEDTLS_CTR_DRBG_USE_128_BIT_KEY below.
* To use AES-128 instead, enable \c MBEDTLS_CTR_DRBG_USE_128_BIT_KEY above.
*
* \note To achieve a 256-bit security strength with CTR_DRBG,
* you must use AES-256 *and* use sufficient entropy.
* See ctr_drbg.h for more details.
*
* Module: library/ctr_drbg.c
* Caller:
@ -3041,7 +3052,6 @@
//#define MBEDTLS_CTR_DRBG_MAX_INPUT 256 /**< Maximum number of additional input bytes */
//#define MBEDTLS_CTR_DRBG_MAX_REQUEST 1024 /**< Maximum number of requested bytes per call */
//#define MBEDTLS_CTR_DRBG_MAX_SEED_INPUT 384 /**< Maximum size of (re)seed buffer */
//#define MBEDTLS_CTR_DRBG_USE_128_BIT_KEY /**< Use 128-bit key for CTR_DRBG - may reduce security (see ctr_drbg.h) */
/* HMAC_DRBG options */
//#define MBEDTLS_HMAC_DRBG_RESEED_INTERVAL 10000 /**< Interval before reseed is performed by default */

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@ -1,7 +1,8 @@
/**
* \file ctr_drbg.h
*
* \brief This file contains CTR_DRBG definitions and functions.
* \brief This file contains definitions and functions for the
* CTR_DRBG pseudorandom generator.
*
* CTR_DRBG is a standardized way of building a PRNG from a block-cipher
* in counter mode operation, as defined in <em>NIST SP 800-90A:
@ -9,13 +10,35 @@
* Bit Generators</em>.
*
* The Mbed TLS implementation of CTR_DRBG uses AES-256 (default) or AES-128
* as the underlying block cipher.
* (if \c MBEDTLS_CTR_DRBG_USE_128_BIT_KEY is enabled at compile time)
* as the underlying block cipher, with a derivation function.
* The initial seeding grabs #MBEDTLS_CTR_DRBG_ENTROPY_LEN bytes of entropy.
* See the documentation of mbedtls_ctr_drbg_seed() for more details.
*
* \warning Using 128-bit keys for CTR_DRBG limits the security of generated
* keys and operations that use random values generated to 128-bit security.
* Based on NIST SP 800-90A §10.2.1 table 3 and NIST SP 800-57 part 1 table 2,
* here are the security strengths achieved in typical configuration:
* - 256 bits under the default configuration of the library, with AES-256
* and with #MBEDTLS_CTR_DRBG_ENTROPY_LEN set to 48 or more.
* - 256 bits if AES-256 is used, #MBEDTLS_CTR_DRBG_ENTROPY_LEN is set
* to 32 or more, and the DRBG is initialized with an explicit
* nonce in the \c custom parameter to mbedtls_ctr_drbg_seed().
* - 128 bits if AES-256 is used but #MBEDTLS_CTR_DRBG_ENTROPY_LEN is
* between 24 and 47 and the DRBG is not initialized with an explicit
* nonce (see mbedtls_ctr_drbg_seed()).
* - 128 bits if AES-128 is used (\c MBEDTLS_CTR_DRBG_USE_128_BIT_KEY enabled)
* and #MBEDTLS_CTR_DRBG_ENTROPY_LEN is set to 24 or more (which is
* always the case unless it is explicitly set to a different value
* in config.h).
*
* Note that the value of #MBEDTLS_CTR_DRBG_ENTROPY_LEN defaults to:
* - \c 48 if the module \c MBEDTLS_SHA512_C is enabled and the symbol
* \c MBEDTLS_ENTROPY_FORCE_SHA256 is disabled at compile time.
* This is the default configuration of the library.
* - \c 32 if the module \c MBEDTLS_SHA512_C is disabled at compile time.
* - \c 32 if \c MBEDTLS_ENTROPY_FORCE_SHA256 is enabled at compile time.
*/
/*
* Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
* Copyright (C) 2006-2019, Arm Limited (or its affiliates), All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
@ -56,9 +79,19 @@
#define MBEDTLS_CTR_DRBG_BLOCKSIZE 16 /**< The block size used by the cipher. */
#if defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY)
#define MBEDTLS_CTR_DRBG_KEYSIZE 16 /**< The key size used by the cipher (compile-time choice: 128 bits). */
#define MBEDTLS_CTR_DRBG_KEYSIZE 16
/**< The key size in bytes used by the cipher.
*
* Compile-time choice: 16 bytes (128 bits)
* because #MBEDTLS_CTR_DRBG_USE_128_BIT_KEY is enabled.
*/
#else
#define MBEDTLS_CTR_DRBG_KEYSIZE 32 /**< The key size used by the cipher (compile-time choice: 256 bits). */
#define MBEDTLS_CTR_DRBG_KEYSIZE 32
/**< The key size in bytes used by the cipher.
*
* Compile-time choice: 32 bytes (256 bits)
* because \c MBEDTLS_CTR_DRBG_USE_128_BIT_KEY is disabled.
*/
#endif
#define MBEDTLS_CTR_DRBG_KEYBITS ( MBEDTLS_CTR_DRBG_KEYSIZE * 8 ) /**< The key size for the DRBG operation, in bits. */
@ -73,21 +106,31 @@
* \{
*/
/** \def MBEDTLS_CTR_DRBG_ENTROPY_LEN
*
* \brief The amount of entropy used per seed by default, in bytes.
*/
#if !defined(MBEDTLS_CTR_DRBG_ENTROPY_LEN)
#if defined(MBEDTLS_SHA512_C) && !defined(MBEDTLS_ENTROPY_FORCE_SHA256)
/** This is 48 bytes because the entropy module uses SHA-512
* (\c MBEDTLS_ENTROPY_FORCE_SHA256 is disabled).
*/
#define MBEDTLS_CTR_DRBG_ENTROPY_LEN 48
/**< The amount of entropy used per seed by default:
* <ul><li>48 with SHA-512.</li>
* <li>32 with SHA-256.</li></ul>
#else /* defined(MBEDTLS_SHA512_C) && !defined(MBEDTLS_ENTROPY_FORCE_SHA256) */
/** This is 32 bytes because the entropy module uses SHA-256
* (the SHA512 module is disabled or
* \c MBEDTLS_ENTROPY_FORCE_SHA256 is enabled).
*/
#else
#if !defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY)
/** \warning To achieve a 256-bit security strength, you must pass a nonce
* to mbedtls_ctr_drbg_seed().
*/
#endif /* !defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY) */
#define MBEDTLS_CTR_DRBG_ENTROPY_LEN 32
/**< Amount of entropy used per seed by default:
* <ul><li>48 with SHA-512.</li>
* <li>32 with SHA-256.</li></ul>
*/
#endif
#endif
#endif /* defined(MBEDTLS_SHA512_C) && !defined(MBEDTLS_ENTROPY_FORCE_SHA256) */
#endif /* !defined(MBEDTLS_CTR_DRBG_ENTROPY_LEN) */
#if !defined(MBEDTLS_CTR_DRBG_RESEED_INTERVAL)
#define MBEDTLS_CTR_DRBG_RESEED_INTERVAL 10000
@ -106,7 +149,7 @@
#if !defined(MBEDTLS_CTR_DRBG_MAX_SEED_INPUT)
#define MBEDTLS_CTR_DRBG_MAX_SEED_INPUT 384
/**< The maximum size of seed or reseed buffer. */
/**< The maximum size of seed or reseed buffer in bytes. */
#endif
/* \} name SECTION: Module settings */
@ -164,17 +207,62 @@ void mbedtls_ctr_drbg_init( mbedtls_ctr_drbg_context *ctx );
* \brief This function seeds and sets up the CTR_DRBG
* entropy source for future reseeds.
*
* \note Personalization data can be provided in addition to the more generic
* entropy source, to make this instantiation as unique as possible.
* A typical choice for the \p f_entropy and \p p_entropy parameters is
* to use the entropy module:
* - \p f_entropy is mbedtls_entropy_func();
* - \p p_entropy is an instance of ::mbedtls_entropy_context initialized
* with mbedtls_entropy_init() (which registers the platform's default
* entropy sources).
*
* \p f_entropy is always called with a buffer size equal to the entropy
* length. The entropy length is initially #MBEDTLS_CTR_DRBG_ENTROPY_LEN
* and this value is always used for the initial seeding. You can change
* the entropy length for subsequent seeding by calling
* mbedtls_ctr_drbg_set_entropy_len() after this function.
*
* You can provide a personalization string in addition to the
* entropy source, to make this instantiation as unique as possible.
*
* \note The _seed_material_ value passed to the derivation
* function in the CTR_DRBG Instantiate Process
* described in NIST SP 800-90A §10.2.1.3.2
* is the concatenation of the string obtained from
* calling \p f_entropy and the \p custom string.
* The origin of the nonce depends on the value of
* the entropy length relative to the security strength.
* - If the entropy length is at least 1.5 times the
* security strength then the nonce is taken from the
* string obtained with \p f_entropy.
* - If the entropy length is less than the security
* strength, then the nonce is taken from \p custom.
* In this case, for compliance with SP 800-90A,
* you must pass a unique value of \p custom at
* each invocation. See SP 800-90A §8.6.7 for more
* details.
*/
#if MBEDTLS_CTR_DRBG_ENTROPY_LEN < MBEDTLS_CTR_DRBG_KEYSIZE * 3 / 2
/** \warning When #MBEDTLS_CTR_DRBG_ENTROPY_LEN is less than
* #MBEDTLS_CTR_DRBG_KEYSIZE * 3 / 2, to achieve the
* maximum security strength permitted by CTR_DRBG,
* you must pass a value of \p custom that is a nonce:
* this value must never be repeated in subsequent
* runs of the same application or on a different
* device.
*/
#endif
/**
* \param ctx The CTR_DRBG context to seed.
* \param f_entropy The entropy callback, taking as arguments the
* \p p_entropy context, the buffer to fill, and the
length of the buffer.
* \param p_entropy The entropy context.
* \param custom Personalization data, that is device-specific
identifiers. Can be NULL.
* \param len The length of the personalization data.
* length of the buffer.
* \param p_entropy The entropy context to pass to \p f_entropy.
* \param custom The personalization string.
* This can be \c NULL, in which case the personalization
* string is empty regardless of the value of \p len.
* \param len The length of the personalization string.
* This must be at most
* #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT
* - #MBEDTLS_CTR_DRBG_ENTROPY_LEN.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED on failure.
@ -197,7 +285,8 @@ void mbedtls_ctr_drbg_free( mbedtls_ctr_drbg_context *ctx );
* The default value is off.
*
* \note If enabled, entropy is gathered at the beginning of
* every call to mbedtls_ctr_drbg_random_with_add().
* every call to mbedtls_ctr_drbg_random_with_add()
* or mbedtls_ctr_drbg_random().
* Only use this if your entropy source has sufficient
* throughput.
*
@ -209,18 +298,42 @@ void mbedtls_ctr_drbg_set_prediction_resistance( mbedtls_ctr_drbg_context *ctx,
/**
* \brief This function sets the amount of entropy grabbed on each
* seed or reseed. The default value is
* #MBEDTLS_CTR_DRBG_ENTROPY_LEN.
* subsequent reseed.
*
* The default value is #MBEDTLS_CTR_DRBG_ENTROPY_LEN.
*
* \note mbedtls_ctr_drbg_seed() always sets the entropy length
* to #MBEDTLS_CTR_DRBG_ENTROPY_LEN, so this function
* only has an effect when it is called after
* mbedtls_ctr_drbg_seed().
*
* \note The security strength of CTR_DRBG is bounded by the
* entropy length. Thus:
* - When using AES-256
* (\c MBEDTLS_CTR_DRBG_USE_128_BIT_KEY is disabled,
* which is the default),
* \p len must be at least 32 (in bytes)
* to achieve a 256-bit strength.
* - When using AES-128
* (\c MBEDTLS_CTR_DRBG_USE_128_BIT_KEY is enabled)
* \p len must be at least 16 (in bytes)
* to achieve a 128-bit strength.
*
* \param ctx The CTR_DRBG context.
* \param len The amount of entropy to grab.
* \param len The amount of entropy to grab, in bytes.
* This must be at most #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT.
*/
void mbedtls_ctr_drbg_set_entropy_len( mbedtls_ctr_drbg_context *ctx,
size_t len );
/**
* \brief This function sets the reseed interval.
* The default value is #MBEDTLS_CTR_DRBG_RESEED_INTERVAL.
*
* The reseed interval is the number of calls to mbedtls_ctr_drbg_random()
* or mbedtls_ctr_drbg_random_with_add() after which the entropy function
* is called again.
*
* The default value is #MBEDTLS_CTR_DRBG_RESEED_INTERVAL.
*
* \param ctx The CTR_DRBG context.
* \param interval The reseed interval.
@ -233,8 +346,12 @@ void mbedtls_ctr_drbg_set_reseed_interval( mbedtls_ctr_drbg_context *ctx,
* extracts data from the entropy source.
*
* \param ctx The CTR_DRBG context.
* \param additional Additional data to add to the state. Can be NULL.
* \param additional Additional data to add to the state. Can be \c NULL.
* \param len The length of the additional data.
* This must be less than
* #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT - \c entropy_len
* where \c entropy_len is the entropy length
* configured for the context.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED on failure.
@ -246,7 +363,8 @@ int mbedtls_ctr_drbg_reseed( mbedtls_ctr_drbg_context *ctx,
* \brief This function updates the state of the CTR_DRBG context.
*
* \param ctx The CTR_DRBG context.
* \param additional The data to update the state with.
* \param additional The data to update the state with. This must not be
* \c NULL unless \p add_len is \c 0.
* \param add_len Length of \p additional in bytes. This must be at
* most #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT.
*
@ -264,14 +382,23 @@ int mbedtls_ctr_drbg_update_ret( mbedtls_ctr_drbg_context *ctx,
* \brief This function updates a CTR_DRBG instance with additional
* data and uses it to generate random data.
*
* \note The function automatically reseeds if the reseed counter is exceeded.
* This function automatically reseeds if the reseed counter is exceeded
* or prediction resistance is enabled.
*
* \param p_rng The CTR_DRBG context. This must be a pointer to a
* #mbedtls_ctr_drbg_context structure.
* \param output The buffer to fill.
* \param output_len The length of the buffer.
* \param additional Additional data to update. Can be NULL.
* \param add_len The length of the additional data.
* \param output_len The length of the buffer in bytes.
* \param additional Additional data to update. Can be \c NULL, in which
* case the additional data is empty regardless of
* the value of \p add_len.
* \param add_len The length of the additional data
* if \p additional is not \c NULL.
* This must be less than #MBEDTLS_CTR_DRBG_MAX_INPUT
* and less than
* #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT - \c entropy_len
* where \c entropy_len is the entropy length
* configured for the context.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED or
@ -284,12 +411,14 @@ int mbedtls_ctr_drbg_random_with_add( void *p_rng,
/**
* \brief This function uses CTR_DRBG to generate random data.
*
* \note The function automatically reseeds if the reseed counter is exceeded.
* This function automatically reseeds if the reseed counter is exceeded
* or prediction resistance is enabled.
*
*
* \param p_rng The CTR_DRBG context. This must be a pointer to a
* #mbedtls_ctr_drbg_context structure.
* \param output The buffer to fill.
* \param output_len The length of the buffer.
* \param output_len The length of the buffer in bytes.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED or
@ -336,7 +465,7 @@ MBEDTLS_DEPRECATED void mbedtls_ctr_drbg_update(
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR on file error.
* \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED on
* \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED on reseed
* failure.
*/
int mbedtls_ctr_drbg_write_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path );
@ -350,8 +479,10 @@ int mbedtls_ctr_drbg_write_seed_file( mbedtls_ctr_drbg_context *ctx, const char
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR on file error.
* \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED or
* #MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG on failure.
* \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED on
* reseed failure.
* \return #MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG if the existing
* seed file is too large.
*/
int mbedtls_ctr_drbg_update_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path );
#endif /* MBEDTLS_FS_IO */

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@ -1,10 +1,14 @@
/**
* \file hmac_drbg.h
*
* \brief HMAC_DRBG (NIST SP 800-90A)
* \brief The HMAC_DRBG pseudorandom generator.
*
* This module implements the HMAC_DRBG pseudorandom generator described
* in <em>NIST SP 800-90A: Recommendation for Random Number Generation Using
* Deterministic Random Bit Generators</em>.
*/
/*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* Copyright (C) 2006-2019, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
@ -104,38 +108,74 @@ typedef struct mbedtls_hmac_drbg_context
} mbedtls_hmac_drbg_context;
/**
* \brief HMAC_DRBG context initialization
* Makes the context ready for mbedtls_hmac_drbg_seed(),
* mbedtls_hmac_drbg_seed_buf() or
* mbedtls_hmac_drbg_free().
* \brief HMAC_DRBG context initialization.
*
* \param ctx HMAC_DRBG context to be initialized
* This function makes the context ready for mbedtls_hmac_drbg_seed(),
* mbedtls_hmac_drbg_seed_buf() or mbedtls_hmac_drbg_free().
*
* \param ctx HMAC_DRBG context to be initialized.
*/
void mbedtls_hmac_drbg_init( mbedtls_hmac_drbg_context *ctx );
/**
* \brief HMAC_DRBG initial seeding
* Seed and setup entropy source for future reseeds.
* \brief HMAC_DRBG initial seeding.
*
* \param ctx HMAC_DRBG context to be seeded
* \param md_info MD algorithm to use for HMAC_DRBG
* \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
* Set the initial seed and set up the entropy source for future reseeds.
*
* \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.
* A typical choice for the \p f_entropy and \p p_entropy parameters is
* to use the entropy module:
* - \p f_entropy is mbedtls_entropy_func();
* - \p p_entropy is an instance of ::mbedtls_entropy_context initialized
* with mbedtls_entropy_init() (which registers the platform's default
* entropy sources).
*
* You can provide a personalization string in addition to the
* entropy source, to make this instantiation as unique as possible.
*
* \note By default, the security strength as defined by NIST is:
* - 128 bits if \p md_info is SHA-1;
* - 192 bits if \p md_info is SHA-224;
* - 256 bits if \p md_info is SHA-256, SHA-384 or SHA-512.
* Note that SHA-256 is just as efficient as SHA-224.
* The security strength can be reduced if a smaller
* entropy length is set with
* mbedtls_hmac_drbg_set_entropy_len() afterwards.
*
* \return 0 if successful, or
* MBEDTLS_ERR_MD_BAD_INPUT_DATA, or
* MBEDTLS_ERR_MD_ALLOC_FAILED, or
* MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED.
* \note The entropy length for the initial seeding is
* the security strength (converted from bits to bytes).
* You can set a different entropy length for subsequent
* seeding by calling mbedtls_hmac_drbg_set_entropy_len()
* after this function.
*
* \note During the initial seeding, this function calls
* the entropy source to obtain a nonce
* whose length is half the entropy length.
*
* \param ctx HMAC_DRBG context to be seeded.
* \param md_info MD algorithm to use for HMAC_DRBG.
* \param f_entropy The entropy callback, taking as arguments the
* \p p_entropy context, the buffer to fill, and the
* length of the buffer.
* \p f_entropy is always called with a length that is
* less than or equal to the entropy length.
* \param p_entropy The entropy context to pass to \p f_entropy.
* \param custom The personalization string.
* This can be \c NULL, in which case the personalization
* string is empty regardless of the value of \p len.
* \param len The length of the personalization string.
* This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT
* and also at most
* #MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT - \p entropy_len * 3 / 2
* where \p entropy_len is the entropy length
* described above.
*
* \return \c 0 if successful.
* \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info is
* invalid.
* \return #MBEDTLS_ERR_MD_ALLOC_FAILED if there was not enough
* memory to allocate context data.
* \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
* if the call to \p f_entropy failed.
*/
int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
const mbedtls_md_info_t * md_info,
@ -146,98 +186,136 @@ int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
/**
* \brief Initilisation of simpified HMAC_DRBG (never reseeds).
* (For use with deterministic ECDSA.)
*
* \param ctx HMAC_DRBG context to be initialised
* \param md_info MD algorithm to use for HMAC_DRBG
* \param data Concatenation of entropy string and additional data
* \param data_len Length of data in bytes
* This function is meant for use in algorithms that need a pseudorandom
* input such as deterministic ECDSA.
*
* \return 0 if successful, or
* MBEDTLS_ERR_MD_BAD_INPUT_DATA, or
* MBEDTLS_ERR_MD_ALLOC_FAILED.
* \param ctx HMAC_DRBG context to be initialised.
* \param md_info MD algorithm to use for HMAC_DRBG.
* \param data Concatenation of the initial entropy string and
* the additional data.
* \param data_len Length of \p data in bytes.
*
* \return \c 0 if successful. or
* \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info is
* invalid.
* \return #MBEDTLS_ERR_MD_ALLOC_FAILED if there was not enough
* memory to allocate context data.
*/
int mbedtls_hmac_drbg_seed_buf( mbedtls_hmac_drbg_context *ctx,
const mbedtls_md_info_t * md_info,
const unsigned char *data, size_t data_len );
/**
* \brief Enable / disable prediction resistance (Default: Off)
* \brief This function turns prediction resistance on or off.
* The default value is 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!
* \note If enabled, entropy is gathered at the beginning of
* every call to mbedtls_hmac_drbg_random_with_add()
* or mbedtls_hmac_drbg_random().
* Only use this if your entropy source has sufficient
* throughput.
*
* \param ctx HMAC_DRBG context
* \param resistance MBEDTLS_HMAC_DRBG_PR_ON or MBEDTLS_HMAC_DRBG_PR_OFF
* \param ctx The HMAC_DRBG context.
* \param resistance #MBEDTLS_HMAC_DRBG_PR_ON or #MBEDTLS_HMAC_DRBG_PR_OFF.
*/
void mbedtls_hmac_drbg_set_prediction_resistance( mbedtls_hmac_drbg_context *ctx,
int resistance );
/**
* \brief Set the amount of entropy grabbed on each reseed
* (Default: given by the security strength, which
* depends on the hash used, see \c mbedtls_hmac_drbg_init() )
* \brief This function sets the amount of entropy grabbed on each
* reseed.
*
* \param ctx HMAC_DRBG context
* \param len Amount of entropy to grab, in bytes
* The default value is set by mbedtls_hmac_drbg_seed().
*
* \note mbedtls_hmac_drbg_seed() always sets the entropy length
* to the default value based on the chosen MD algorithm,
* so this function only has an effect if it is called
* after mbedtls_hmac_drbg_seed().
*
* \param ctx The HMAC_DRBG context.
* \param len The amount of entropy to grab, in bytes.
*/
void mbedtls_hmac_drbg_set_entropy_len( mbedtls_hmac_drbg_context *ctx,
size_t len );
/**
* \brief Set the reseed interval
* (Default: MBEDTLS_HMAC_DRBG_RESEED_INTERVAL)
* \brief Set the reseed interval.
*
* \param ctx HMAC_DRBG context
* \param interval Reseed interval
* The reseed interval is the number of calls to mbedtls_hmac_drbg_random()
* or mbedtls_hmac_drbg_random_with_add() after which the entropy function
* is called again.
*
* The default value is #MBEDTLS_HMAC_DRBG_RESEED_INTERVAL.
*
* \param ctx The HMAC_DRBG context.
* \param interval The reseed interval.
*/
void mbedtls_hmac_drbg_set_reseed_interval( mbedtls_hmac_drbg_context *ctx,
int interval );
/**
* \brief HMAC_DRBG update state
* \brief This function updates the state of the HMAC_DRBG context.
*
* \param ctx HMAC_DRBG context
* \param additional Additional data to update state with, or NULL
* \param add_len Length of additional data, or 0
* \param ctx The HMAC_DRBG context.
* \param additional The data to update the state with.
* If this is \c NULL, there is no additional data.
* \param add_len Length of \p additional in bytes.
* Unused if \p additional is \c NULL.
*
* \return \c 0 on success, or an error from the underlying
* hash calculation.
*
* \note Additional data is optional, pass NULL and 0 as second
* third argument if no additional data is being used.
*/
int mbedtls_hmac_drbg_update_ret( mbedtls_hmac_drbg_context *ctx,
const unsigned char *additional, size_t add_len );
/**
* \brief HMAC_DRBG reseeding (extracts data from entropy source)
* \brief This function reseeds the HMAC_DRBG context, that is
* extracts data from the entropy source.
*
* \param ctx HMAC_DRBG context
* \param additional Additional data to add to state (Can be NULL)
* \param len Length of additional data
* \param ctx The HMAC_DRBG context.
* \param additional Additional data to add to the state.
* If this is \c NULL, there is no additional data
* and \p len should be \c 0.
* \param len The length of the additional data.
* This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT
* and also at most
* #MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT - \p entropy_len
* where \p entropy_len is the entropy length
* (see mbedtls_hmac_drbg_set_entropy_len()).
*
* \return 0 if successful, or
* MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
* \return \c 0 if successful.
* \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
* if a call to the entropy function failed.
*/
int mbedtls_hmac_drbg_reseed( mbedtls_hmac_drbg_context *ctx,
const unsigned char *additional, size_t len );
/**
* \brief HMAC_DRBG generate random with additional update input
* \brief This function updates an HMAC_DRBG instance with additional
* data and uses it to generate random data.
*
* Note: Automatically reseeds if reseed_counter is reached or PR is enabled.
* This function automatically reseeds if the reseed counter is exceeded
* or prediction resistance is enabled.
*
* \param p_rng HMAC_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 (can be 0)
* \param p_rng The HMAC_DRBG context. This must be a pointer to a
* #mbedtls_hmac_drbg_context structure.
* \param output The buffer to fill.
* \param output_len The length of the buffer in bytes.
* This must be at most #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
* \param additional Additional data to update with.
* If this is \c NULL, there is no additional data
* and \p add_len should be \c 0.
* \param add_len The length of the additional data.
* This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT.
*
* \return 0 if successful, or
* MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED, or
* MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG, or
* MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG.
* \return \c 0 if successful.
* \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
* if a call to the entropy source failed.
* \return #MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG if
* \p output_len > #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
* \return #MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG if
* \p add_len > #MBEDTLS_HMAC_DRBG_MAX_INPUT.
*/
int mbedtls_hmac_drbg_random_with_add( void *p_rng,
unsigned char *output, size_t output_len,
@ -245,24 +323,29 @@ int mbedtls_hmac_drbg_random_with_add( void *p_rng,
size_t add_len );
/**
* \brief HMAC_DRBG generate random
* \brief This function uses HMAC_DRBG to generate random data.
*
* Note: Automatically reseeds if reseed_counter is reached or PR is enabled.
* This function automatically reseeds if the reseed counter is exceeded
* or prediction resistance is enabled.
*
* \param p_rng HMAC_DRBG context
* \param output Buffer to fill
* \param out_len Length of the buffer
* \param p_rng The HMAC_DRBG context. This must be a pointer to a
* #mbedtls_hmac_drbg_context structure.
* \param output The buffer to fill.
* \param out_len The length of the buffer in bytes.
* This must be at most #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
*
* \return 0 if successful, or
* MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED, or
* MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG
* \return \c 0 if successful.
* \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
* if a call to the entropy source failed.
* \return #MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG if
* \p out_len > #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
*/
int mbedtls_hmac_drbg_random( void *p_rng, unsigned char *output, size_t out_len );
/**
* \brief Free an HMAC_DRBG context
*
* \param ctx HMAC_DRBG context to free.
* \param ctx The HMAC_DRBG context to free.
*/
void mbedtls_hmac_drbg_free( mbedtls_hmac_drbg_context *ctx );
@ -273,17 +356,16 @@ void mbedtls_hmac_drbg_free( mbedtls_hmac_drbg_context *ctx );
#define MBEDTLS_DEPRECATED
#endif
/**
* \brief HMAC_DRBG update state
* \brief This function updates the state of the HMAC_DRBG context.
*
* \deprecated Superseded by mbedtls_hmac_drbg_update_ret()
* in 2.16.0.
*
* \param ctx HMAC_DRBG context
* \param additional Additional data to update state with, or NULL
* \param 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.
* \param ctx The HMAC_DRBG context.
* \param additional The data to update the state with.
* If this is \c NULL, there is no additional data.
* \param add_len Length of \p additional in bytes.
* Unused if \p additional is \c NULL.
*/
MBEDTLS_DEPRECATED void mbedtls_hmac_drbg_update(
mbedtls_hmac_drbg_context *ctx,
@ -293,26 +375,31 @@ MBEDTLS_DEPRECATED void mbedtls_hmac_drbg_update(
#if defined(MBEDTLS_FS_IO)
/**
* \brief Write a seed file
* \brief This function writes a seed file.
*
* \param ctx HMAC_DRBG context
* \param path Name of the file
* \param ctx The HMAC_DRBG context.
* \param path The name of the file.
*
* \return 0 if successful, 1 on file error, or
* MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
* \return \c 0 on success.
* \return #MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR on file error.
* \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED on reseed
* failure.
*/
int mbedtls_hmac_drbg_write_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path );
/**
* \brief Read and update a seed file. Seed is added to this
* instance
* \brief This function reads and updates a seed file. The seed
* is added to this instance.
*
* \param ctx HMAC_DRBG context
* \param path Name of the file
* \param ctx The HMAC_DRBG context.
* \param path The name of the file.
*
* \return 0 if successful, 1 on file error,
* MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED or
* MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG
* \return \c 0 on success.
* \return #MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR on file error.
* \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED on
* reseed failure.
* \return #MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG if the existing
* seed file is too large.
*/
int mbedtls_hmac_drbg_update_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path );
#endif /* MBEDTLS_FS_IO */
@ -320,9 +407,10 @@ int mbedtls_hmac_drbg_update_seed_file( mbedtls_hmac_drbg_context *ctx, const ch
#if defined(MBEDTLS_SELF_TEST)
/**
* \brief Checkup routine
* \brief The HMAC_DRBG Checkup routine.
*
* \return 0 if successful, or 1 if the test failed
* \return \c 0 if successful.
* \return \c 1 if the test failed.
*/
int mbedtls_hmac_drbg_self_test( int verbose );
#endif

View file

@ -297,6 +297,9 @@ static const char *features[] = {
#if defined(MBEDTLS_CIPHER_PADDING_ZEROS)
"MBEDTLS_CIPHER_PADDING_ZEROS",
#endif /* MBEDTLS_CIPHER_PADDING_ZEROS */
#if defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY)
"MBEDTLS_CTR_DRBG_USE_128_BIT_KEY",
#endif /* MBEDTLS_CTR_DRBG_USE_128_BIT_KEY */
#if defined(MBEDTLS_ENABLE_WEAK_CIPHERSUITES)
"MBEDTLS_ENABLE_WEAK_CIPHERSUITES",
#endif /* MBEDTLS_ENABLE_WEAK_CIPHERSUITES */

View file

@ -834,6 +834,14 @@ int query_config( const char *config )
}
#endif /* MBEDTLS_CIPHER_PADDING_ZEROS */
#if defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY)
if( strcmp( "MBEDTLS_CTR_DRBG_USE_128_BIT_KEY", config ) == 0 )
{
MACRO_EXPANSION_TO_STR( MBEDTLS_CTR_DRBG_USE_128_BIT_KEY );
return( 0 );
}
#endif /* MBEDTLS_CTR_DRBG_USE_128_BIT_KEY */
#if defined(MBEDTLS_ENABLE_WEAK_CIPHERSUITES)
if( strcmp( "MBEDTLS_ENABLE_WEAK_CIPHERSUITES", config ) == 0 )
{
@ -2114,14 +2122,6 @@ int query_config( const char *config )
}
#endif /* MBEDTLS_CTR_DRBG_MAX_SEED_INPUT */
#if defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY)
if( strcmp( "MBEDTLS_CTR_DRBG_USE_128_BIT_KEY", config ) == 0 )
{
MACRO_EXPANSION_TO_STR( MBEDTLS_CTR_DRBG_USE_128_BIT_KEY );
return( 0 );
}
#endif /* MBEDTLS_CTR_DRBG_USE_128_BIT_KEY */
#if defined(MBEDTLS_HMAC_DRBG_RESEED_INTERVAL)
if( strcmp( "MBEDTLS_HMAC_DRBG_RESEED_INTERVAL", config ) == 0 )
{

View file

@ -87,6 +87,7 @@ MBEDTLS_TEST_NULL_ENTROPY
MBEDTLS_DEPRECATED_REMOVED
MBEDTLS_HAVE_SSE2
MBEDTLS_PLATFORM_NO_STD_FUNCTIONS
MBEDTLS_CTR_DRBG_USE_128_BIT_KEY
MBEDTLS_ECP_DP_M221_ENABLED
MBEDTLS_ECP_DP_M383_ENABLED
MBEDTLS_ECP_DP_M511_ENABLED