Function mbedtls_hmac_drbg_random_with_add 

pub unsafe extern "C" fn mbedtls_hmac_drbg_random_with_add(
    p_rng: *mut c_void,
    output: *mut c_uchar,
    output_len: usize,
    additional: *const c_uchar,
    add_len: usize,
) -> c_int

\brief 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.

\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 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 \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.