1 /*
2  *  Copyright (c) 2019, The OpenThread Authors.
3  *  All rights reserved.
4  *
5  *  Redistribution and use in source and binary forms, with or without
6  *  modification, are permitted provided that the following conditions are met:
7  *  1. Redistributions of source code must retain the above copyright
8  *     notice, this list of conditions and the following disclaimer.
9  *  2. Redistributions in binary form must reproduce the above copyright
10  *     notice, this list of conditions and the following disclaimer in the
11  *     documentation and/or other materials provided with the distribution.
12  *  3. Neither the name of the copyright holder nor the
13  *     names of its contributors may be used to endorse or promote products
14  *     derived from this software without specific prior written permission.
15  *
16  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  *  POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /**
30  * @file
31  * @brief
32  *   This file includes the platform abstraction for entropy generation.
33  */
34 
35 #ifndef OPENTHREAD_PLATFORM_ENTROPY_H_
36 #define OPENTHREAD_PLATFORM_ENTROPY_H_
37 
38 #include <stdint.h>
39 
40 #include <openthread/error.h>
41 
42 #ifdef __cplusplus
43 extern "C" {
44 #endif
45 
46 /**
47  * @addtogroup plat-entropy
48  *
49  * @brief
50  *   This module includes the platform abstraction for entropy generation.
51  *
52  * @{
53  *
54  */
55 
56 /**
57  * Fill buffer with entropy.
58  *
59  * This function MUST be implemented using a true random number generator (TRNG).
60  *
61  * @param[out]  aOutput              A pointer to where the true random values are placed.  Must not be NULL.
62  * @param[in]   aOutputLength        Size of @p aBuffer.
63  *
64  * @retval OT_ERROR_NONE          Successfully filled @p aBuffer with true random values.
65  * @retval OT_ERROR_FAILED        Failed to fill @p aBuffer with true random values.
66  * @retval OT_ERROR_INVALID_ARGS  @p aBuffer was set to NULL.
67  *
68  */
69 otError otPlatEntropyGet(uint8_t *aOutput, uint16_t aOutputLength);
70 
71 /**
72  * @}
73  *
74  */
75 
76 #ifdef __cplusplus
77 } // end of extern "C"
78 #endif
79 
80 #endif // OPENTHREAD_PLATFORM_ENTROPY_H_
81