1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
/*
* Hex Encoding and Decoding
* (C) 2010 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/hex.h>
#include <botan/mem_ops.h>
#include <stdexcept>
namespace Botan {
void hex_encode(char output[],
const byte input[],
u32bit input_length,
bool uppercase)
{
static const byte BIN_TO_HEX_UPPER[16] = {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'A', 'B', 'C', 'D', 'E', 'F' };
static const byte BIN_TO_HEX_LOWER[16] = {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'a', 'b', 'c', 'd', 'e', 'f' };
const byte* tbl = uppercase ? BIN_TO_HEX_UPPER : BIN_TO_HEX_LOWER;
for(u32bit i = 0; i != input_length; ++i)
{
byte x = input[i];
output[2*i ] = tbl[(x >> 4) & 0x0F];
output[2*i+1] = tbl[(x ) & 0x0F];
}
}
std::string hex_encode(const byte input[],
u32bit input_length,
bool uppercase)
{
std::string output(2 * input_length, 0);
hex_encode(&output[0], input, input_length, uppercase);
return output;
}
u32bit hex_decode(byte output[],
const char input[],
u32bit input_length,
u32bit& input_consumed,
bool ignore_ws)
{
/*
* Mapping of hex characters to either their binary equivalent
* or to an error code.
* If valid hex (0-9 A-F a-f), the value.
* If whitespace, then 0x80
* Otherwise 0xFF
* Warning: this table assumes ASCII character encodings
*/
static const byte HEX_TO_BIN[256] = {
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x80,
0x80, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0x80, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x01,
0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
0x0F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x0A, 0x0B, 0x0C,
0x0D, 0x0E, 0x0F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
byte* out_ptr = output;
bool top_nibble = true;
clear_mem(output, input_length / 2);
for(u32bit i = 0; i != input_length; ++i)
{
const byte bin = HEX_TO_BIN[(byte)input[i]];
if(bin >= 0x10)
{
if(bin == 0x80 && ignore_ws)
continue;
std::string bad_char(1, input[i]);
if(bad_char == "\t")
bad_char = "\\t";
else if(bad_char == "\n")
bad_char = "\\n";
throw std::invalid_argument(
std::string("hex_decode: invalid hex character '") +
bad_char + "'");
}
*out_ptr |= bin << (top_nibble*4);
top_nibble = !top_nibble;
if(top_nibble)
++out_ptr;
}
input_consumed = input_length;
u32bit written = (out_ptr - output);
/*
* We only got half of a byte at the end; zap the half-written
* output and mark it as unread
*/
if(!top_nibble)
{
*out_ptr = 0;
input_consumed -= 1;
}
return written;
}
u32bit hex_decode(byte output[],
const char input[],
u32bit input_length,
bool ignore_ws)
{
u32bit consumed = 0;
u32bit written = hex_decode(output, input, input_length,
consumed, ignore_ws);
if(consumed != input_length)
throw std::invalid_argument("hex_decode: input did not have full bytes");
return written;
}
u32bit hex_decode(byte output[],
const std::string& input,
bool ignore_ws)
{
return hex_decode(output, &input[0], input.length(), ignore_ws);
}
SecureVector<byte> hex_decode(const char input[],
u32bit input_length,
bool ignore_ws)
{
SecureVector<byte> bin(input_length / 2);
u32bit written = hex_decode(&bin[0],
input,
input_length,
ignore_ws);
bin.truncate(written);
return bin;
}
SecureVector<byte> hex_decode(const std::string& input,
bool ignore_ws)
{
return hex_decode(&input[0], input.size(), ignore_ws);
}
}
|
