1 /*
2  *  Copyright (c) 2016, 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  *   This file includes definitions for using mbedTLS.
32  */
33 
34 #ifndef OT_MBEDTLS_HPP_
35 #define OT_MBEDTLS_HPP_
36 
37 #include "openthread-core-config.h"
38 
39 #include <mbedtls/version.h>
40 
41 #include <openthread/instance.h>
42 
43 #include "common/error.hpp"
44 #include "common/non_copyable.hpp"
45 
46 /**
47  * Keep forward-compatibility with Mbed TLS 3.0.
48  *
49  * Direct access to fields of structures declared in public headers is no longer
50  * supported. In Mbed TLS 3, the layout of structures is not considered part of
51  * the stable API, and minor versions (3.1, 3.2, etc.) may add, remove, rename,
52  * reorder or change the type of structure fields.
53  */
54 #if (MBEDTLS_VERSION_NUMBER < 0x03000000)
55 #ifndef MBEDTLS_PRIVATE
56 #define MBEDTLS_PRIVATE(member) member
57 #endif
58 #endif
59 
60 namespace ot {
61 namespace Crypto {
62 
63 /**
64  * @addtogroup core-security
65  *
66  * @{
67  *
68  */
69 
70 /**
71  * Implements mbedTLS memory.
72  *
73  */
74 class MbedTls : private NonCopyable
75 {
76 public:
77     /**
78      * Initializes the object.
79      *
80      */
81     MbedTls(void);
82 
83     /**
84      * Converts an mbed TLS error to OpenThread error.
85      *
86      * @param[in] aMbedTlsError  The mbed TLS error.
87      *
88      * @returns The mapped Error.
89      *
90      */
91     static Error MapError(int aMbedTlsError);
92 
93 #if !OPENTHREAD_RADIO
94     /**
95      * Fills a given buffer with cryptographically secure random bytes.
96      *
97      * @param[in]  aContext A pointer to arbitrary context.
98      * @param[out] aBuffer  A pointer to a buffer to fill with the random bytes.
99      * @param[in]  aSize    Size of buffer (number of bytes to fill).
100      *
101      * @retval kErrorNone   Successfully filled buffer with random values.
102      *
103      */
104     static int CryptoSecurePrng(void *aContext, unsigned char *aBuffer, size_t aSize);
105 #endif
106 };
107 
108 /**
109  * @}
110  *
111  */
112 
113 } // namespace Crypto
114 } // namespace ot
115 
116 #endif // OT_MBEDTLS_HPP_
117