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
|
/*
* Copyright (C) 2010 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <ipxe/base16.h>
/** @file
*
* Base16 encoding
*
*/
/**
* Base16-encode data
*
* @v raw Raw data
* @v len Length of raw data
* @v encoded Buffer for encoded string
*
* The buffer must be the correct length for the encoded string. Use
* something like
*
* char buf[ base16_encoded_len ( len ) + 1 ];
*
* (the +1 is for the terminating NUL) to provide a buffer of the
* correct size.
*/
void base16_encode ( const uint8_t *raw, size_t len, char *encoded ) {
const uint8_t *raw_bytes = raw;
char *encoded_bytes = encoded;
size_t remaining = len;
/* Encode each byte */
for ( ; remaining-- ; encoded_bytes += 2 ) {
sprintf ( encoded_bytes, "%02x", *(raw_bytes++) );
}
/* Ensure terminating NUL exists even if length was zero */
*encoded_bytes = '\0';
DBG ( "Base16-encoded to \"%s\":\n", encoded );
DBG_HDA ( 0, raw, len );
assert ( strlen ( encoded ) == base16_encoded_len ( len ) );
}
/**
* Decode hexadecimal string
*
* @v encoded Encoded string
* @v separator Byte separator character, or 0 for no separator
* @v data Buffer
* @v len Length of buffer
* @ret len Length of data, or negative error
*/
int hex_decode ( const char *encoded, char separator, void *data, size_t len ) {
uint8_t *out = data;
unsigned int count = 0;
unsigned int sixteens;
unsigned int units;
while ( *encoded ) {
/* Check separator, if applicable */
if ( count && separator && ( ( *(encoded++) != separator ) ) )
return -EINVAL;
/* Extract digits. Note that either digit may be NUL,
* which would be interpreted as an invalid value by
* strtoul_charval(); there is therefore no need for an
* explicit end-of-string check.
*/
sixteens = strtoul_charval ( *(encoded++) );
if ( sixteens >= 16 )
return -EINVAL;
units = strtoul_charval ( *(encoded++) );
if ( units >= 16 )
return -EINVAL;
/* Store result */
if ( count < len )
out[count] = ( ( sixteens << 4 ) | units );
count++;
}
return count;
}
/**
* Base16-decode data
*
* @v encoded Encoded string
* @v raw Raw data
* @ret len Length of raw data, or negative error
*
* The buffer must be large enough to contain the decoded data. Use
* something like
*
* char buf[ base16_decoded_max_len ( encoded ) ];
*
* to provide a buffer of the correct size.
*/
int base16_decode ( const char *encoded, uint8_t *raw ) {
int len;
len = hex_decode ( encoded, 0, raw, -1UL );
if ( len < 0 )
return len;
DBG ( "Base16-decoded \"%s\" to:\n", encoded );
DBG_HDA ( 0, raw, len );
assert ( len <= ( int ) base16_decoded_max_len ( encoded ) );
return len;
}
|
