1 // SPDX-License-Identifier: Apache-2.0
2 // SPDX-FileCopyrightText: Copyright OpenBMC Authors
3 #pragma once
4
5 #include <array>
6 #include <cstddef>
7 #include <cstdint>
8 #include <string>
9 #include <vector>
10
11 static constexpr std::array<char, 16> digitsArray = {
12 '0', '1', '2', '3', '4', '5', '6', '7',
13 '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
14
intToHexString(uint64_t value,size_t digits)15 inline std::string intToHexString(uint64_t value, size_t digits)
16 {
17 std::string rc(digits, '0');
18 size_t bitIndex = (digits - 1) * 4;
19 for (size_t digitIndex = 0; digitIndex < digits; digitIndex++)
20 {
21 rc[digitIndex] = digitsArray[(value >> bitIndex) & 0x0f];
22 bitIndex -= 4;
23 }
24 return rc;
25 }
26
bytesToHexString(const std::vector<uint8_t> & bytes)27 inline std::string bytesToHexString(const std::vector<uint8_t>& bytes)
28 {
29 std::string rc(bytes.size() * 2, '0');
30 for (size_t i = 0; i < bytes.size(); ++i)
31 {
32 rc[i * 2] = digitsArray[(bytes[i] & 0xf0) >> 4];
33 rc[i * 2 + 1] = digitsArray[bytes[i] & 0x0f];
34 }
35 return rc;
36 }
37
38 // Returns nibble.
hexCharToNibble(char ch)39 inline uint8_t hexCharToNibble(char ch)
40 {
41 uint8_t rc = 16;
42 if (ch >= '0' && ch <= '9')
43 {
44 rc = static_cast<uint8_t>(ch) - '0';
45 }
46 else if (ch >= 'A' && ch <= 'F')
47 {
48 rc = static_cast<uint8_t>(ch - 'A') + 10U;
49 }
50 else if (ch >= 'a' && ch <= 'f')
51 {
52 rc = static_cast<uint8_t>(ch - 'a') + 10U;
53 }
54
55 return rc;
56 }
57
58 // Returns empty vector in case of malformed hex-string.
hexStringToBytes(const std::string & str)59 inline std::vector<uint8_t> hexStringToBytes(const std::string& str)
60 {
61 std::vector<uint8_t> rc(str.size() / 2, 0);
62 for (size_t i = 0; i < str.length(); i += 2)
63 {
64 uint8_t hi = hexCharToNibble(str[i]);
65 if (i == str.length() - 1)
66 {
67 return {};
68 }
69 uint8_t lo = hexCharToNibble(str[i + 1]);
70 if (lo == 16 || hi == 16)
71 {
72 return {};
73 }
74
75 rc[i / 2] = static_cast<uint8_t>(hi << 4) | lo;
76 }
77 return rc;
78 }
79