1/**
2 * \file entropy_poll.h
3 *
4 * \brief Platform-specific and custom entropy polling functions
5 */
6/*
7 *  Copyright The Mbed TLS Contributors
8 *  SPDX-License-Identifier: Apache-2.0
9 *
10 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
11 *  not use this file except in compliance with the License.
12 *  You may obtain a copy of the License at
13 *
14 *  http://www.apache.org/licenses/LICENSE-2.0
15 *
16 *  Unless required by applicable law or agreed to in writing, software
17 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
18 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19 *  See the License for the specific language governing permissions and
20 *  limitations under the License.
21 */
22#ifndef MBEDTLS_ENTROPY_POLL_H
23#define MBEDTLS_ENTROPY_POLL_H
24
25#include "mbedtls/build_info.h"
26
27#include <stddef.h>
28
29#ifdef __cplusplus
30extern "C" {
31#endif
32
33/*
34 * Default thresholds for built-in sources, in bytes
35 */
36#define MBEDTLS_ENTROPY_MIN_PLATFORM     32     /**< Minimum for platform source    */
37#if !defined(MBEDTLS_ENTROPY_MIN_HARDWARE)
38#define MBEDTLS_ENTROPY_MIN_HARDWARE     32     /**< Minimum for the hardware source */
39#endif
40
41#if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
42/**
43 * \brief           Platform-specific entropy poll callback
44 */
45int mbedtls_platform_entropy_poll(void *data,
46                                  unsigned char *output, size_t len, size_t *olen);
47#endif
48
49#if defined(MBEDTLS_ENTROPY_HARDWARE_ALT)
50/**
51 * \brief           Entropy poll callback for a hardware source
52 *
53 * \warning         This is not provided by mbed TLS!
54 *                  See \c MBEDTLS_ENTROPY_HARDWARE_ALT in mbedtls_config.h.
55 *
56 * \note            This must accept NULL as its first argument.
57 */
58int mbedtls_hardware_poll(void *data,
59                          unsigned char *output, size_t len, size_t *olen);
60#endif
61
62#if defined(MBEDTLS_ENTROPY_NV_SEED)
63/**
64 * \brief           Entropy poll callback for a non-volatile seed file
65 *
66 * \note            This must accept NULL as its first argument.
67 */
68int mbedtls_nv_seed_poll(void *data,
69                         unsigned char *output, size_t len, size_t *olen);
70#endif
71
72#ifdef __cplusplus
73}
74#endif
75
76#endif /* entropy_poll.h */
77