582 lines
24 KiB
C
582 lines
24 KiB
C
/**
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* \file ctr_drbg.h
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*
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* \brief This file contains definitions and functions for the
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* CTR_DRBG pseudorandom generator.
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*
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* CTR_DRBG is a standardized way of building a PRNG from a block-cipher
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* in counter mode operation, as defined in <em>NIST SP 800-90A:
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* Recommendation for Random Number Generation Using Deterministic Random
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* Bit Generators</em>.
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*
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* The Mbed TLS implementation of CTR_DRBG uses AES-256 (default) or AES-128
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* (if \c MBEDTLS_CTR_DRBG_USE_128_BIT_KEY is enabled at compile time)
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* as the underlying block cipher, with a derivation function.
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*
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* The security strength as defined in NIST SP 800-90A is
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* 128 bits when AES-128 is used (\c MBEDTLS_CTR_DRBG_USE_128_BIT_KEY enabled)
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* and 256 bits otherwise, provided that #MBEDTLS_CTR_DRBG_ENTROPY_LEN is
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* kept at its default value (and not overridden in mbedtls_config.h) and that the
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* DRBG instance is set up with default parameters.
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* See the documentation of mbedtls_ctr_drbg_seed() for more
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* information.
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*/
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/*
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* Copyright The Mbed TLS Contributors
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* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
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*/
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#ifndef MBEDTLS_CTR_DRBG_H
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#define MBEDTLS_CTR_DRBG_H
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#include "mbedtls/private_access.h"
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#include "mbedtls/build_info.h"
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/* In case AES_C is defined then it is the primary option for backward
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* compatibility purposes. If that's not available, PSA is used instead */
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#if defined(MBEDTLS_AES_C)
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#include "mbedtls/aes.h"
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#else
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#include "psa/crypto.h"
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#endif
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#include "entropy.h"
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#if defined(MBEDTLS_THREADING_C)
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#include "mbedtls/threading.h"
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#endif
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/** The entropy source failed. */
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#define MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED -0x0034
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/** The requested random buffer length is too big. */
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#define MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG -0x0036
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/** The input (entropy + additional data) is too large. */
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#define MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG -0x0038
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/** Read or write error in file. */
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#define MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR -0x003A
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#define MBEDTLS_CTR_DRBG_BLOCKSIZE 16 /**< The block size used by the cipher. */
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#if defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY)
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#define MBEDTLS_CTR_DRBG_KEYSIZE 16
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/**< The key size in bytes used by the cipher.
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*
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* Compile-time choice: 16 bytes (128 bits)
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* because #MBEDTLS_CTR_DRBG_USE_128_BIT_KEY is enabled.
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*/
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#else
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#define MBEDTLS_CTR_DRBG_KEYSIZE 32
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/**< The key size in bytes used by the cipher.
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*
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* Compile-time choice: 32 bytes (256 bits)
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* because \c MBEDTLS_CTR_DRBG_USE_128_BIT_KEY is disabled.
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*/
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#endif
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#define MBEDTLS_CTR_DRBG_KEYBITS (MBEDTLS_CTR_DRBG_KEYSIZE * 8) /**< The key size for the DRBG operation, in bits. */
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#define MBEDTLS_CTR_DRBG_SEEDLEN (MBEDTLS_CTR_DRBG_KEYSIZE + MBEDTLS_CTR_DRBG_BLOCKSIZE) /**< The seed length, calculated as (counter + AES key). */
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/**
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* \name SECTION: Module settings
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*
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* The configuration options you can set for this module are in this section.
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* Either change them in mbedtls_config.h or define them using the compiler command
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* line.
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* \{
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*/
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/** \def MBEDTLS_CTR_DRBG_ENTROPY_LEN
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*
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* \brief The amount of entropy used per seed by default, in bytes.
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*/
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#if !defined(MBEDTLS_CTR_DRBG_ENTROPY_LEN)
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#if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
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/** This is 48 bytes because the entropy module uses SHA-512.
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*/
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#define MBEDTLS_CTR_DRBG_ENTROPY_LEN 48
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#else /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */
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/** This is 32 bytes because the entropy module uses SHA-256.
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*/
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#if !defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY)
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/** \warning To achieve a 256-bit security strength, you must pass a nonce
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* to mbedtls_ctr_drbg_seed().
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*/
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#endif /* !defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY) */
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#define MBEDTLS_CTR_DRBG_ENTROPY_LEN 32
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#endif /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */
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#endif /* !defined(MBEDTLS_CTR_DRBG_ENTROPY_LEN) */
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#if !defined(MBEDTLS_CTR_DRBG_RESEED_INTERVAL)
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#define MBEDTLS_CTR_DRBG_RESEED_INTERVAL 10000
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/**< The interval before reseed is performed by default. */
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#endif
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#if !defined(MBEDTLS_CTR_DRBG_MAX_INPUT)
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#define MBEDTLS_CTR_DRBG_MAX_INPUT 256
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/**< The maximum number of additional input Bytes. */
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#endif
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#if !defined(MBEDTLS_CTR_DRBG_MAX_REQUEST)
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#define MBEDTLS_CTR_DRBG_MAX_REQUEST 1024
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/**< The maximum number of requested Bytes per call. */
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#endif
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#if !defined(MBEDTLS_CTR_DRBG_MAX_SEED_INPUT)
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#define MBEDTLS_CTR_DRBG_MAX_SEED_INPUT 384
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/**< The maximum size of seed or reseed buffer in bytes. */
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#endif
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/** \} name SECTION: Module settings */
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#define MBEDTLS_CTR_DRBG_PR_OFF 0
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/**< Prediction resistance is disabled. */
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#define MBEDTLS_CTR_DRBG_PR_ON 1
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/**< Prediction resistance is enabled. */
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#ifdef __cplusplus
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extern "C" {
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#endif
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#if MBEDTLS_CTR_DRBG_ENTROPY_LEN >= MBEDTLS_CTR_DRBG_KEYSIZE * 3 / 2
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/** The default length of the nonce read from the entropy source.
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*
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* This is \c 0 because a single read from the entropy source is sufficient
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* to include a nonce.
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* See the documentation of mbedtls_ctr_drbg_seed() for more information.
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*/
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#define MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN 0
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#else
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/** The default length of the nonce read from the entropy source.
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*
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* This is half of the default entropy length because a single read from
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* the entropy source does not provide enough material to form a nonce.
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* See the documentation of mbedtls_ctr_drbg_seed() for more information.
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*/
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#define MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN (MBEDTLS_CTR_DRBG_ENTROPY_LEN + 1) / 2
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#endif
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#if !defined(MBEDTLS_AES_C)
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typedef struct mbedtls_ctr_drbg_psa_context {
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mbedtls_svc_key_id_t key_id;
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psa_cipher_operation_t operation;
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} mbedtls_ctr_drbg_psa_context;
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#endif
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/**
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* \brief The CTR_DRBG context structure.
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*/
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typedef struct mbedtls_ctr_drbg_context {
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unsigned char MBEDTLS_PRIVATE(counter)[16]; /*!< The counter (V). */
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int MBEDTLS_PRIVATE(reseed_counter); /*!< The reseed counter.
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* This is the number of requests that have
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* been made since the last (re)seeding,
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* minus one.
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* Before the initial seeding, this field
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* contains the amount of entropy in bytes
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* to use as a nonce for the initial seeding,
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* or -1 if no nonce length has been explicitly
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* set (see mbedtls_ctr_drbg_set_nonce_len()).
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*/
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int MBEDTLS_PRIVATE(prediction_resistance); /*!< This determines whether prediction
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resistance is enabled, that is
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whether to systematically reseed before
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each random generation. */
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size_t MBEDTLS_PRIVATE(entropy_len); /*!< The amount of entropy grabbed on each
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seed or reseed operation, in bytes. */
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int MBEDTLS_PRIVATE(reseed_interval); /*!< The reseed interval.
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* This is the maximum number of requests
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* that can be made between reseedings. */
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#if defined(MBEDTLS_AES_C)
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mbedtls_aes_context MBEDTLS_PRIVATE(aes_ctx); /*!< The AES context. */
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#else
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mbedtls_ctr_drbg_psa_context MBEDTLS_PRIVATE(psa_ctx); /*!< The PSA context. */
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#endif
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/*
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* Callbacks (Entropy)
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*/
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int(*MBEDTLS_PRIVATE(f_entropy))(void *, unsigned char *, size_t);
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/*!< The entropy callback function. */
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void *MBEDTLS_PRIVATE(p_entropy); /*!< The context for the entropy function. */
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#if defined(MBEDTLS_THREADING_C)
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/* Invariant: the mutex is initialized if and only if f_entropy != NULL.
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* This means that the mutex is initialized during the initial seeding
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* in mbedtls_ctr_drbg_seed() and freed in mbedtls_ctr_drbg_free().
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*
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* Note that this invariant may change without notice. Do not rely on it
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* and do not access the mutex directly in application code.
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*/
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mbedtls_threading_mutex_t MBEDTLS_PRIVATE(mutex);
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#endif
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}
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mbedtls_ctr_drbg_context;
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/**
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* \brief This function initializes the CTR_DRBG context,
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* and prepares it for mbedtls_ctr_drbg_seed()
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* or mbedtls_ctr_drbg_free().
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*
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* \note The reseed interval is
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* #MBEDTLS_CTR_DRBG_RESEED_INTERVAL by default.
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* You can override it by calling
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* mbedtls_ctr_drbg_set_reseed_interval().
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*
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* \param ctx The CTR_DRBG context to initialize.
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*/
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void mbedtls_ctr_drbg_init(mbedtls_ctr_drbg_context *ctx);
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/**
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* \brief This function seeds and sets up the CTR_DRBG
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* entropy source for future reseeds.
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*
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* A typical choice for the \p f_entropy and \p p_entropy parameters is
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* to use the entropy module:
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* - \p f_entropy is mbedtls_entropy_func();
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* - \p p_entropy is an instance of ::mbedtls_entropy_context initialized
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* with mbedtls_entropy_init() (which registers the platform's default
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* entropy sources).
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*
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* The entropy length is #MBEDTLS_CTR_DRBG_ENTROPY_LEN by default.
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* You can override it by calling mbedtls_ctr_drbg_set_entropy_len().
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*
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* The entropy nonce length is:
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* - \c 0 if the entropy length is at least 3/2 times the entropy length,
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* which guarantees that the security strength is the maximum permitted
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* by the key size and entropy length according to NIST SP 800-90A §10.2.1;
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* - Half the entropy length otherwise.
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* You can override it by calling mbedtls_ctr_drbg_set_nonce_len().
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* With the default entropy length, the entropy nonce length is
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* #MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN.
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*
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* You can provide a nonce and personalization string in addition to the
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* entropy source, to make this instantiation as unique as possible.
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* See SP 800-90A §8.6.7 for more details about nonces.
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*
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* The _seed_material_ value passed to the derivation function in
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* the CTR_DRBG Instantiate Process described in NIST SP 800-90A §10.2.1.3.2
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* is the concatenation of the following strings:
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* - A string obtained by calling \p f_entropy function for the entropy
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* length.
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*/
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#if MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN == 0
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/**
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* - If mbedtls_ctr_drbg_set_nonce_len() has been called, a string
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* obtained by calling \p f_entropy function for the specified length.
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*/
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#else
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/**
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* - A string obtained by calling \p f_entropy function for the entropy nonce
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* length. If the entropy nonce length is \c 0, this function does not
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* make a second call to \p f_entropy.
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*/
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#endif
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#if defined(MBEDTLS_THREADING_C)
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/**
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* \note When Mbed TLS is built with threading support,
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* after this function returns successfully,
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* it is safe to call mbedtls_ctr_drbg_random()
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* from multiple threads. Other operations, including
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* reseeding, are not thread-safe.
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*/
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#endif /* MBEDTLS_THREADING_C */
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/**
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* - The \p custom string.
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*
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* \note To achieve the nominal security strength permitted
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* by CTR_DRBG, the entropy length must be:
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* - at least 16 bytes for a 128-bit strength
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* (maximum achievable strength when using AES-128);
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* - at least 32 bytes for a 256-bit strength
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* (maximum achievable strength when using AES-256).
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*
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* In addition, if you do not pass a nonce in \p custom,
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* the sum of the entropy length
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* and the entropy nonce length must be:
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* - at least 24 bytes for a 128-bit strength
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* (maximum achievable strength when using AES-128);
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* - at least 48 bytes for a 256-bit strength
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* (maximum achievable strength when using AES-256).
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*
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* \param ctx The CTR_DRBG context to seed.
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* It must have been initialized with
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* mbedtls_ctr_drbg_init().
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* After a successful call to mbedtls_ctr_drbg_seed(),
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* you may not call mbedtls_ctr_drbg_seed() again on
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* the same context unless you call
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* mbedtls_ctr_drbg_free() and mbedtls_ctr_drbg_init()
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* again first.
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* After a failed call to mbedtls_ctr_drbg_seed(),
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* you must call mbedtls_ctr_drbg_free().
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* \param f_entropy The entropy callback, taking as arguments the
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* \p p_entropy context, the buffer to fill, and the
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* length of the buffer.
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* \p f_entropy is always called with a buffer size
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* less than or equal to the entropy length.
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* \param p_entropy The entropy context to pass to \p f_entropy.
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* \param custom The personalization string.
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* This can be \c NULL, in which case the personalization
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* string is empty regardless of the value of \p len.
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* \param len The length of the personalization string.
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* This must be at most
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* #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT
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* - #MBEDTLS_CTR_DRBG_ENTROPY_LEN.
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*
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* \return \c 0 on success.
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* \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED on failure.
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*/
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int mbedtls_ctr_drbg_seed(mbedtls_ctr_drbg_context *ctx,
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int (*f_entropy)(void *, unsigned char *, size_t),
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void *p_entropy,
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const unsigned char *custom,
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size_t len);
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/**
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* \brief This function resets CTR_DRBG context to the state immediately
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* after initial call of mbedtls_ctr_drbg_init().
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*
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* \param ctx The CTR_DRBG context to clear.
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*/
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void mbedtls_ctr_drbg_free(mbedtls_ctr_drbg_context *ctx);
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/**
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* \brief This function turns prediction resistance on or off.
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* The default value is off.
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*
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* \note If enabled, entropy is gathered at the beginning of
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* every call to mbedtls_ctr_drbg_random_with_add()
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* or mbedtls_ctr_drbg_random().
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* Only use this if your entropy source has sufficient
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* throughput.
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*
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* \param ctx The CTR_DRBG context.
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* \param resistance #MBEDTLS_CTR_DRBG_PR_ON or #MBEDTLS_CTR_DRBG_PR_OFF.
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*/
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void mbedtls_ctr_drbg_set_prediction_resistance(mbedtls_ctr_drbg_context *ctx,
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int resistance);
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/**
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* \brief This function sets the amount of entropy grabbed on each
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* seed or reseed.
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*
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* The default value is #MBEDTLS_CTR_DRBG_ENTROPY_LEN.
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*
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* \note The security strength of CTR_DRBG is bounded by the
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* entropy length. Thus:
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* - When using AES-256
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* (\c MBEDTLS_CTR_DRBG_USE_128_BIT_KEY is disabled,
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* which is the default),
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* \p len must be at least 32 (in bytes)
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* to achieve a 256-bit strength.
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* - When using AES-128
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* (\c MBEDTLS_CTR_DRBG_USE_128_BIT_KEY is enabled)
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* \p len must be at least 16 (in bytes)
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* to achieve a 128-bit strength.
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*
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* \param ctx The CTR_DRBG context.
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* \param len The amount of entropy to grab, in bytes.
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* This must be at most #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT
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* and at most the maximum length accepted by the
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* entropy function that is set in the context.
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*/
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void mbedtls_ctr_drbg_set_entropy_len(mbedtls_ctr_drbg_context *ctx,
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size_t len);
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/**
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* \brief This function sets the amount of entropy grabbed
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* as a nonce for the initial seeding.
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*
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* Call this function before calling mbedtls_ctr_drbg_seed() to read
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* a nonce from the entropy source during the initial seeding.
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*
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* \param ctx The CTR_DRBG context.
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* \param len The amount of entropy to grab for the nonce, in bytes.
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* This must be at most #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT
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* and at most the maximum length accepted by the
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* entropy function that is set in the context.
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*
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* \return \c 0 on success.
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* \return #MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG if \p len is
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* more than #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT.
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* \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED
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* if the initial seeding has already taken place.
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*/
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int mbedtls_ctr_drbg_set_nonce_len(mbedtls_ctr_drbg_context *ctx,
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size_t len);
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/**
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* \brief This function sets the reseed interval.
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*
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* The reseed interval is the number of calls to mbedtls_ctr_drbg_random()
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* or mbedtls_ctr_drbg_random_with_add() after which the entropy function
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* is called again.
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*
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* The default value is #MBEDTLS_CTR_DRBG_RESEED_INTERVAL.
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*
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* \param ctx The CTR_DRBG context.
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* \param interval The reseed interval.
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*/
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void mbedtls_ctr_drbg_set_reseed_interval(mbedtls_ctr_drbg_context *ctx,
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int interval);
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|
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/**
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|
* \brief This function reseeds the CTR_DRBG context, that is
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* extracts data from the entropy source.
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*
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* \note This function is not thread-safe. It is not safe
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* to call this function if another thread might be
|
|
* concurrently obtaining random numbers from the same
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* context or updating or reseeding the same context.
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*
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* \param ctx The CTR_DRBG context.
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|
* \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 */
|