1 /*
2 * Copyright (c) 2017, 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 provides kinds of convertion functions.
32 */
33
34 #include "utils/hex.hpp"
35
36 #include <string>
37
38 #include <stdio.h>
39 #include <string.h>
40
41 namespace otbr {
42
43 namespace Utils {
44
Hex2Bytes(const char * aHex,uint8_t * aBytes,uint16_t aBytesLength)45 int Hex2Bytes(const char *aHex, uint8_t *aBytes, uint16_t aBytesLength)
46 {
47 size_t hexLength = strlen(aHex);
48 const char *hexEnd = aHex + hexLength;
49 uint8_t *cur = aBytes;
50 uint8_t numChars = hexLength & 1;
51 uint8_t byte = 0;
52
53 if ((hexLength + 1) / 2 > aBytesLength)
54 {
55 return -1;
56 }
57
58 while (aHex < hexEnd)
59 {
60 if ('A' <= *aHex && *aHex <= 'F')
61 {
62 byte |= 10 + (*aHex - 'A');
63 }
64 else if ('a' <= *aHex && *aHex <= 'f')
65 {
66 byte |= 10 + (*aHex - 'a');
67 }
68 else if ('0' <= *aHex && *aHex <= '9')
69 {
70 byte |= *aHex - '0';
71 }
72 else
73 {
74 return -1;
75 }
76
77 aHex++;
78 numChars++;
79
80 if (numChars >= 2)
81 {
82 numChars = 0;
83 *cur++ = byte;
84 byte = 0;
85 }
86 else
87 {
88 byte <<= 4;
89 }
90 }
91
92 return static_cast<int>(cur - aBytes);
93 }
94
Bytes2Hex(const uint8_t * aBytes,const uint16_t aBytesLength,char * aHex)95 size_t Bytes2Hex(const uint8_t *aBytes, const uint16_t aBytesLength, char *aHex)
96 {
97 char byteHex[3];
98
99 // Make sure strcat appends at the beginning of the output buffer even
100 // if uninitialized.
101 aHex[0] = '\0';
102
103 for (int i = 0; i < aBytesLength; i++)
104 {
105 snprintf(byteHex, sizeof(byteHex), "%02X", aBytes[i]);
106 strcat(aHex, byteHex);
107 }
108
109 return strlen(aHex);
110 }
111
Bytes2Hex(const uint8_t * aBytes,const uint16_t aBytesLength)112 std::string Bytes2Hex(const uint8_t *aBytes, const uint16_t aBytesLength)
113 {
114 char hex[2 * aBytesLength + 1];
115 std::string s;
116 size_t len;
117
118 len = Bytes2Hex(aBytes, aBytesLength, hex);
119 s = std::string(hex, len);
120
121 return s;
122 }
123
Long2Hex(const uint64_t aLong,char * aHex)124 size_t Long2Hex(const uint64_t aLong, char *aHex)
125 {
126 char byteHex[3];
127 uint64_t longValue = aLong;
128
129 // Make sure strcat appends at the beginning of the output buffer even
130 // if uninitialized.
131 aHex[0] = '\0';
132
133 for (uint8_t i = 0; i < sizeof(uint64_t); i++)
134 {
135 uint8_t byte = longValue & 0xff;
136 snprintf(byteHex, sizeof(byteHex), "%02X", byte);
137 strcat(aHex, byteHex);
138 longValue = longValue >> 8;
139 }
140
141 return strlen(aHex);
142 }
143
144 } // namespace Utils
145
146 } // namespace otbr
147