mbedtls_hmac_drbg_random_with_add() function

This function updates an HMAC_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.

Syntax

Show:

Summary

Declaration

Definition

from hmac_drbg.h:346

int mbedtls_hmac_drbg_random_with_add(void *p_rng, unsigned char *output, size_t output_len, const unsigned char *additional, size_t add_len);

Implemented in hmac_drbg.c:306

Arguments

Argument

Description

p_rng

The HMAC_DRBG context. This must be a pointer to a #mbedtls_hmac_drbg_context structure.

output

The buffer to fill.

output_len

The length of the buffer in bytes. This must be at most #MBEDTLS_HMAC_DRBG_MAX_REQUEST.

additional

Additional data to update with. If this is \c NULL, there is no additional data and \p add_len should be \c 0.

add_len

The length of the additional data. This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT.

Return value

\c 0 if successful. #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED if a call to the entropy source failed. #MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG if \p output_len > #MBEDTLS_HMAC_DRBG_MAX_REQUEST. #MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG if \p add_len > #MBEDTLS_HMAC_DRBG_MAX_INPUT.

Notes

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.