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Diffstat (limited to 'include/mbedtls/ctr_drbg.h')
| -rw-r--r-- | include/mbedtls/ctr_drbg.h | 564 |
1 files changed, 0 insertions, 564 deletions
diff --git a/include/mbedtls/ctr_drbg.h b/include/mbedtls/ctr_drbg.h deleted file mode 100644 index d1f19e6..0000000 --- a/include/mbedtls/ctr_drbg.h +++ /dev/null @@ -1,564 +0,0 @@ -/** - * \file ctr_drbg.h - * - * \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: - * Recommendation for Random Number Generation Using Deterministic Random - * Bit Generators</em>. - * - * The Mbed TLS implementation of CTR_DRBG uses AES-256 (default) or AES-128 - * (if \c MBEDTLS_CTR_DRBG_USE_128_BIT_KEY is enabled at compile time) - * as the underlying block cipher, with a derivation function. - * - * The security strength as defined in NIST SP 800-90A is - * 128 bits when AES-128 is used (\c MBEDTLS_CTR_DRBG_USE_128_BIT_KEY enabled) - * and 256 bits otherwise, provided that #MBEDTLS_CTR_DRBG_ENTROPY_LEN is - * kept at its default value (and not overridden in mbedtls_config.h) and that the - * DRBG instance is set up with default parameters. - * See the documentation of mbedtls_ctr_drbg_seed() for more - * information. - */ -/* - * Copyright The Mbed TLS Contributors - * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later - */ - -#ifndef MBEDTLS_CTR_DRBG_H -#define MBEDTLS_CTR_DRBG_H -#include "mbedtls/private_access.h" - -#include "mbedtls/build_info.h" - -#include "mbedtls/aes.h" -#include "entropy.h" - -#if defined(MBEDTLS_THREADING_C) -#include "mbedtls/threading.h" -#endif - -/** The entropy source failed. */ -#define MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED -0x0034 -/** The requested random buffer length is too big. */ -#define MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG -0x0036 -/** The input (entropy + additional data) is too large. */ -#define MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG -0x0038 -/** Read or write error in file. */ -#define MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR -0x003A - -#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 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 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. */ -#define MBEDTLS_CTR_DRBG_SEEDLEN (MBEDTLS_CTR_DRBG_KEYSIZE + MBEDTLS_CTR_DRBG_BLOCKSIZE) /**< The seed length, calculated as (counter + AES key). */ - -/** - * \name SECTION: Module settings - * - * The configuration options you can set for this module are in this section. - * Either change them in mbedtls_config.h or define them using the compiler command - * line. - * \{ - */ - -/** \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_ENTROPY_SHA512_ACCUMULATOR) -/** This is 48 bytes because the entropy module uses SHA-512. - */ -#define MBEDTLS_CTR_DRBG_ENTROPY_LEN 48 - -#else /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */ - -/** This is 32 bytes because the entropy module uses SHA-256. - */ -#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 -#endif /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */ -#endif /* !defined(MBEDTLS_CTR_DRBG_ENTROPY_LEN) */ - -#if !defined(MBEDTLS_CTR_DRBG_RESEED_INTERVAL) -#define MBEDTLS_CTR_DRBG_RESEED_INTERVAL 10000 -/**< The interval before reseed is performed by default. */ -#endif - -#if !defined(MBEDTLS_CTR_DRBG_MAX_INPUT) -#define MBEDTLS_CTR_DRBG_MAX_INPUT 256 -/**< The maximum number of additional input Bytes. */ -#endif - -#if !defined(MBEDTLS_CTR_DRBG_MAX_REQUEST) -#define MBEDTLS_CTR_DRBG_MAX_REQUEST 1024 -/**< The maximum number of requested Bytes per call. */ -#endif - -#if !defined(MBEDTLS_CTR_DRBG_MAX_SEED_INPUT) -#define MBEDTLS_CTR_DRBG_MAX_SEED_INPUT 384 -/**< The maximum size of seed or reseed buffer in bytes. */ -#endif - -/** \} name SECTION: Module settings */ - -#define MBEDTLS_CTR_DRBG_PR_OFF 0 -/**< Prediction resistance is disabled. */ -#define MBEDTLS_CTR_DRBG_PR_ON 1 -/**< Prediction resistance is enabled. */ - -#ifdef __cplusplus -extern "C" { -#endif - -#if MBEDTLS_CTR_DRBG_ENTROPY_LEN >= MBEDTLS_CTR_DRBG_KEYSIZE * 3 / 2 -/** The default length of the nonce read from the entropy source. - * - * This is \c 0 because a single read from the entropy source is sufficient - * to include a nonce. - * See the documentation of mbedtls_ctr_drbg_seed() for more information. - */ -#define MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN 0 -#else -/** The default length of the nonce read from the entropy source. - * - * This is half of the default entropy length because a single read from - * the entropy source does not provide enough material to form a nonce. - * See the documentation of mbedtls_ctr_drbg_seed() for more information. - */ -#define MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN (MBEDTLS_CTR_DRBG_ENTROPY_LEN + 1) / 2 -#endif - -/** - * \brief The CTR_DRBG context structure. - */ -typedef struct mbedtls_ctr_drbg_context { - unsigned char MBEDTLS_PRIVATE(counter)[16]; /*!< The counter (V). */ - int MBEDTLS_PRIVATE(reseed_counter); /*!< The reseed counter. - * This is the number of requests that have - * been made since the last (re)seeding, - * minus one. - * Before the initial seeding, this field - * contains the amount of entropy in bytes - * to use as a nonce for the initial seeding, - * or -1 if no nonce length has been explicitly - * set (see mbedtls_ctr_drbg_set_nonce_len()). - */ - int MBEDTLS_PRIVATE(prediction_resistance); /*!< This determines whether prediction - resistance is enabled, that is - whether to systematically reseed before - each random generation. */ - size_t MBEDTLS_PRIVATE(entropy_len); /*!< The amount of entropy grabbed on each - seed or reseed operation, in bytes. */ - int MBEDTLS_PRIVATE(reseed_interval); /*!< The reseed interval. - * This is the maximum number of requests - * that can be made between reseedings. */ - - mbedtls_aes_context MBEDTLS_PRIVATE(aes_ctx); /*!< The AES context. */ - - /* - * Callbacks (Entropy) - */ - int(*MBEDTLS_PRIVATE(f_entropy))(void *, unsigned char *, size_t); - /*!< The entropy callback function. */ - - void *MBEDTLS_PRIVATE(p_entropy); /*!< The context for the entropy function. */ - -#if defined(MBEDTLS_THREADING_C) - /* Invariant: the mutex is initialized if and only if f_entropy != NULL. - * This means that the mutex is initialized during the initial seeding - * in mbedtls_ctr_drbg_seed() and freed in mbedtls_ctr_drbg_free(). - * - * Note that this invariant may change without notice. Do not rely on it - * and do not access the mutex directly in application code. - */ - mbedtls_threading_mutex_t MBEDTLS_PRIVATE(mutex); -#endif -} -mbedtls_ctr_drbg_context; - -/** - * \brief This function initializes the CTR_DRBG context, - * and prepares it for mbedtls_ctr_drbg_seed() - * or mbedtls_ctr_drbg_free(). - * - * \note The reseed interval is - * #MBEDTLS_CTR_DRBG_RESEED_INTERVAL by default. - * You can override it by calling - * mbedtls_ctr_drbg_set_reseed_interval(). - * - * \param ctx The CTR_DRBG context to initialize. - */ -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. - * - * 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). - * - * The entropy length is #MBEDTLS_CTR_DRBG_ENTROPY_LEN by default. - * You can override it by calling mbedtls_ctr_drbg_set_entropy_len(). - * - * The entropy nonce length is: - * - \c 0 if the entropy length is at least 3/2 times the entropy length, - * which guarantees that the security strength is the maximum permitted - * by the key size and entropy length according to NIST SP 800-90A §10.2.1; - * - Half the entropy length otherwise. - * You can override it by calling mbedtls_ctr_drbg_set_nonce_len(). - * With the default entropy length, the entropy nonce length is - * #MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN. - * - * You can provide a nonce and personalization string in addition to the - * entropy source, to make this instantiation as unique as possible. - * See SP 800-90A §8.6.7 for more details about nonces. - * - * 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 following strings: - * - A string obtained by calling \p f_entropy function for the entropy - * length. - */ -#if MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN == 0 -/** - * - If mbedtls_ctr_drbg_set_nonce_len() has been called, a string - * obtained by calling \p f_entropy function for the specified length. - */ -#else -/** - * - A string obtained by calling \p f_entropy function for the entropy nonce - * length. If the entropy nonce length is \c 0, this function does not - * make a second call to \p f_entropy. - */ -#endif -#if defined(MBEDTLS_THREADING_C) -/** - * \note When Mbed TLS is built with threading support, - * after this function returns successfully, - * it is safe to call mbedtls_ctr_drbg_random() - * from multiple threads. Other operations, including - * reseeding, are not thread-safe. - */ -#endif /* MBEDTLS_THREADING_C */ -/** - * - The \p custom string. - * - * \note To achieve the nominal security strength permitted - * by CTR_DRBG, the entropy length must be: - * - at least 16 bytes for a 128-bit strength - * (maximum achievable strength when using AES-128); - * - at least 32 bytes for a 256-bit strength - * (maximum achievable strength when using AES-256). - * - * In addition, if you do not pass a nonce in \p custom, - * the sum of the entropy length - * and the entropy nonce length must be: - * - at least 24 bytes for a 128-bit strength - * (maximum achievable strength when using AES-128); - * - at least 48 bytes for a 256-bit strength - * (maximum achievable strength when using AES-256). - * - * \param ctx The CTR_DRBG context to seed. - * It must have been initialized with - * mbedtls_ctr_drbg_init(). - * After a successful call to mbedtls_ctr_drbg_seed(), - * you may not call mbedtls_ctr_drbg_seed() again on - * the same context unless you call - * mbedtls_ctr_drbg_free() and mbedtls_ctr_drbg_init() - * again first. - * After a failed call to mbedtls_ctr_drbg_seed(), - * you must call mbedtls_ctr_drbg_free(). - * \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 buffer size - * 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_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. - */ -int mbedtls_ctr_drbg_seed(mbedtls_ctr_drbg_context *ctx, - int (*f_entropy)(void *, unsigned char *, size_t), - void *p_entropy, - const unsigned char *custom, - size_t len); - -/** - * \brief This function resets CTR_DRBG context to the state immediately - * after initial call of mbedtls_ctr_drbg_init(). - * - * \param ctx The CTR_DRBG context to clear. - */ -void mbedtls_ctr_drbg_free(mbedtls_ctr_drbg_context *ctx); - -/** - * \brief This function turns prediction resistance on or off. - * The default value is off. - * - * \note If enabled, entropy is gathered at the beginning of - * every call to mbedtls_ctr_drbg_random_with_add() - * or mbedtls_ctr_drbg_random(). - * Only use this if your entropy source has sufficient - * throughput. - * - * \param ctx The CTR_DRBG context. - * \param resistance #MBEDTLS_CTR_DRBG_PR_ON or #MBEDTLS_CTR_DRBG_PR_OFF. - */ -void mbedtls_ctr_drbg_set_prediction_resistance(mbedtls_ctr_drbg_context *ctx, - int resistance); - -/** - * \brief This function sets the amount of entropy grabbed on each - * seed or reseed. - * - * The default value is #MBEDTLS_CTR_DRBG_ENTROPY_LEN. - * - * \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, in bytes. - * This must be at most #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT - * and at most the maximum length accepted by the - * entropy function that is set in the context. - */ -void mbedtls_ctr_drbg_set_entropy_len(mbedtls_ctr_drbg_context *ctx, - size_t len); - -/** - * \brief This function sets the amount of entropy grabbed - * as a nonce for the initial seeding. - * - * Call this function before calling mbedtls_ctr_drbg_seed() to read - * a nonce from the entropy source during the initial seeding. - * - * \param ctx The CTR_DRBG context. - * \param len The amount of entropy to grab for the nonce, in bytes. - * This must be at most #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT - * and at most the maximum length accepted by the - * entropy function that is set in the context. - * - * \return \c 0 on success. - * \return #MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG if \p len is - * more than #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT. - * \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED - * if the initial seeding has already taken place. - */ -int mbedtls_ctr_drbg_set_nonce_len(mbedtls_ctr_drbg_context *ctx, - size_t len); - -/** - * \brief This function sets the 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. - */ -void mbedtls_ctr_drbg_set_reseed_interval(mbedtls_ctr_drbg_context *ctx, - int interval); - -/** - * \brief This function reseeds the CTR_DRBG context, that is - * extracts data from the entropy source. - * - * \note This function is not thread-safe. It is not safe - * to call this function if another thread might be - * concurrently obtaining random numbers from the same - * context or updating or reseeding the same context. - * - * \param ctx The CTR_DRBG context. - * \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. - */ -int mbedtls_ctr_drbg_reseed(mbedtls_ctr_drbg_context *ctx, - const unsigned char *additional, size_t len); - -/** - * \brief This function updates the state of the CTR_DRBG context. - * - * \note This function is not thread-safe. It is not safe - * to call this function if another thread might be - * concurrently obtaining random numbers from the same - * context or updating or reseeding the same context. - * - * \param ctx The CTR_DRBG context. - * \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. - * - * \return \c 0 on success. - * \return #MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG if - * \p add_len is more than - * #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT. - * \return An error from the underlying AES cipher on failure. - */ -int mbedtls_ctr_drbg_update(mbedtls_ctr_drbg_context *ctx, - const unsigned char *additional, - size_t add_len); - -/** - * \brief This function updates a CTR_DRBG instance with additional - * data and uses it to generate random data. - * - * This function automatically reseeds if the reseed counter is exceeded - * or prediction resistance is enabled. - * - * \note This function is not thread-safe. It is not safe - * to call this function if another thread might be - * concurrently obtaining random numbers from the same - * context or updating or reseeding the same context. - * - * \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 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 - * #MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG on failure. - */ -int mbedtls_ctr_drbg_random_with_add(void *p_rng, - unsigned char *output, size_t output_len, - const unsigned char *additional, size_t add_len); - -/** - * \brief This function uses CTR_DRBG to generate random data. - * - * This function automatically reseeds if the reseed counter is exceeded - * or prediction resistance is enabled. - */ -#if defined(MBEDTLS_THREADING_C) -/** - * \note When Mbed TLS is built with threading support, - * it is safe to call mbedtls_ctr_drbg_random() - * from multiple threads. Other operations, including - * reseeding, are not thread-safe. - */ -#endif /* MBEDTLS_THREADING_C */ -/** - * \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 in bytes. - * - * \return \c 0 on success. - * \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED or - * #MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG on failure. - */ -int mbedtls_ctr_drbg_random(void *p_rng, - unsigned char *output, size_t output_len); - -#if defined(MBEDTLS_FS_IO) -/** - * \brief This function writes a seed file. - * - * \param ctx The CTR_DRBG context. - * \param path The name of the file. - * - * \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 reseed - * failure. - */ -int mbedtls_ctr_drbg_write_seed_file(mbedtls_ctr_drbg_context *ctx, const char *path); - -/** - * \brief This function reads and updates a seed file. The seed - * is added to this instance. - * - * \param ctx The CTR_DRBG context. - * \param path The name of the file. - * - * \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 - * 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 */ - -#if defined(MBEDTLS_SELF_TEST) - -/** - * \brief The CTR_DRBG checkup routine. - * - * \return \c 0 on success. - * \return \c 1 on failure. - */ -int mbedtls_ctr_drbg_self_test(int verbose); - -#endif /* MBEDTLS_SELF_TEST */ - -#ifdef __cplusplus -} -#endif - -#endif /* ctr_drbg.h */ |