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Diffstat (limited to 'include/mbedtls/psa_util.h')
| -rw-r--r-- | include/mbedtls/psa_util.h | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/include/mbedtls/psa_util.h b/include/mbedtls/psa_util.h new file mode 100644 index 0000000..643e8aa --- /dev/null +++ b/include/mbedtls/psa_util.h @@ -0,0 +1,104 @@ +/** + * \file psa_util.h + * + * \brief Utility functions for the use of the PSA Crypto library. + */ +/* + * Copyright The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later + */ + +#ifndef MBEDTLS_PSA_UTIL_H +#define MBEDTLS_PSA_UTIL_H +#include "mbedtls/private_access.h" + +#include "mbedtls/build_info.h" + +#if defined(MBEDTLS_PSA_CRYPTO_C) + +/* Expose whatever RNG the PSA subsystem uses to applications using the + * mbedtls_xxx API. The declarations and definitions here need to be + * consistent with the implementation in library/psa_crypto_random_impl.h. + * See that file for implementation documentation. */ + + +/* The type of a `f_rng` random generator function that many library functions + * take. + * + * This type name is not part of the Mbed TLS stable API. It may be renamed + * or moved without warning. + */ +typedef int mbedtls_f_rng_t(void *p_rng, unsigned char *output, size_t output_size); + +#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) + +/** The random generator function for the PSA subsystem. + * + * This function is suitable as the `f_rng` random generator function + * parameter of many `mbedtls_xxx` functions. Use #MBEDTLS_PSA_RANDOM_STATE + * to obtain the \p p_rng parameter. + * + * The implementation of this function depends on the configuration of the + * library. + * + * \note Depending on the configuration, this may be a function or + * a pointer to a function. + * + * \note This function may only be used if the PSA crypto subsystem is active. + * This means that you must call psa_crypto_init() before any call to + * this function, and you must not call this function after calling + * mbedtls_psa_crypto_free(). + * + * \param p_rng The random generator context. This must be + * #MBEDTLS_PSA_RANDOM_STATE. No other state is + * supported. + * \param output The buffer to fill. It must have room for + * \c output_size bytes. + * \param output_size The number of bytes to write to \p output. + * This function may fail if \p output_size is too + * large. It is guaranteed to accept any output size + * requested by Mbed TLS library functions. The + * maximum request size depends on the library + * configuration. + * + * \return \c 0 on success. + * \return An `MBEDTLS_ERR_ENTROPY_xxx`, + * `MBEDTLS_ERR_PLATFORM_xxx, + * `MBEDTLS_ERR_CTR_DRBG_xxx` or + * `MBEDTLS_ERR_HMAC_DRBG_xxx` on error. + */ +int mbedtls_psa_get_random(void *p_rng, + unsigned char *output, + size_t output_size); + +/** The random generator state for the PSA subsystem. + * + * This macro expands to an expression which is suitable as the `p_rng` + * random generator state parameter of many `mbedtls_xxx` functions. + * It must be used in combination with the random generator function + * mbedtls_psa_get_random(). + * + * The implementation of this macro depends on the configuration of the + * library. Do not make any assumption on its nature. + */ +#define MBEDTLS_PSA_RANDOM_STATE NULL + +#else /* !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) */ + +#if defined(MBEDTLS_CTR_DRBG_C) +#include "mbedtls/ctr_drbg.h" +typedef mbedtls_ctr_drbg_context mbedtls_psa_drbg_context_t; +static mbedtls_f_rng_t *const mbedtls_psa_get_random = mbedtls_ctr_drbg_random; +#elif defined(MBEDTLS_HMAC_DRBG_C) +#include "mbedtls/hmac_drbg.h" +typedef mbedtls_hmac_drbg_context mbedtls_psa_drbg_context_t; +static mbedtls_f_rng_t *const mbedtls_psa_get_random = mbedtls_hmac_drbg_random; +#endif +extern mbedtls_psa_drbg_context_t *const mbedtls_psa_random_state; + +#define MBEDTLS_PSA_RANDOM_STATE mbedtls_psa_random_state + +#endif /* !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) */ + +#endif /* MBEDTLS_PSA_CRYPTO_C */ +#endif /* MBEDTLS_PSA_UTIL_H */ |