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
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
|
/* Copyright (C) CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
* SPDX-License-Identifier: GPL-3.0-or-later
*/
#include "base64.h"
#include "libknot/errcode.h"
#include <stdlib.h>
#include <stdint.h>
/*! \brief Maximal length of binary input to Base64 encoding. */
#define MAX_BIN_DATA_LEN ((INT32_MAX / 4) * 3)
/*! \brief Base64 padding character. */
static const uint8_t base64_pad = '=';
/*! \brief Base64 alphabet. */
static const uint8_t base64_enc[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
/*! \brief Indicates bad Base64 character. */
#define KO 255
/*! \brief Indicates Base64 padding character. */
#define PD 64
/*! \brief Transformation and validation table for decoding Base64. */
static const uint8_t base64_dec[256] = {
[ 0] = KO, ['+'] = 62, ['V'] = 21, [129] = KO, [172] = KO, [215] = KO,
[ 1] = KO, [ 44] = KO, ['W'] = 22, [130] = KO, [173] = KO, [216] = KO,
[ 2] = KO, [ 45] = KO, ['X'] = 23, [131] = KO, [174] = KO, [217] = KO,
[ 3] = KO, [ 46] = KO, ['Y'] = 24, [132] = KO, [175] = KO, [218] = KO,
[ 4] = KO, ['/'] = 63, ['Z'] = 25, [133] = KO, [176] = KO, [219] = KO,
[ 5] = KO, ['0'] = 52, [ 91] = KO, [134] = KO, [177] = KO, [220] = KO,
[ 6] = KO, ['1'] = 53, [ 92] = KO, [135] = KO, [178] = KO, [221] = KO,
[ 7] = KO, ['2'] = 54, [ 93] = KO, [136] = KO, [179] = KO, [222] = KO,
[ 8] = KO, ['3'] = 55, [ 94] = KO, [137] = KO, [180] = KO, [223] = KO,
[ 9] = KO, ['4'] = 56, [ 95] = KO, [138] = KO, [181] = KO, [224] = KO,
[ 10] = KO, ['5'] = 57, [ 96] = KO, [139] = KO, [182] = KO, [225] = KO,
[ 11] = KO, ['6'] = 58, ['a'] = 26, [140] = KO, [183] = KO, [226] = KO,
[ 12] = KO, ['7'] = 59, ['b'] = 27, [141] = KO, [184] = KO, [227] = KO,
[ 13] = KO, ['8'] = 60, ['c'] = 28, [142] = KO, [185] = KO, [228] = KO,
[ 14] = KO, ['9'] = 61, ['d'] = 29, [143] = KO, [186] = KO, [229] = KO,
[ 15] = KO, [ 58] = KO, ['e'] = 30, [144] = KO, [187] = KO, [230] = KO,
[ 16] = KO, [ 59] = KO, ['f'] = 31, [145] = KO, [188] = KO, [231] = KO,
[ 17] = KO, [ 60] = KO, ['g'] = 32, [146] = KO, [189] = KO, [232] = KO,
[ 18] = KO, ['='] = PD, ['h'] = 33, [147] = KO, [190] = KO, [233] = KO,
[ 19] = KO, [ 62] = KO, ['i'] = 34, [148] = KO, [191] = KO, [234] = KO,
[ 20] = KO, [ 63] = KO, ['j'] = 35, [149] = KO, [192] = KO, [235] = KO,
[ 21] = KO, [ 64] = KO, ['k'] = 36, [150] = KO, [193] = KO, [236] = KO,
[ 22] = KO, ['A'] = 0, ['l'] = 37, [151] = KO, [194] = KO, [237] = KO,
[ 23] = KO, ['B'] = 1, ['m'] = 38, [152] = KO, [195] = KO, [238] = KO,
[ 24] = KO, ['C'] = 2, ['n'] = 39, [153] = KO, [196] = KO, [239] = KO,
[ 25] = KO, ['D'] = 3, ['o'] = 40, [154] = KO, [197] = KO, [240] = KO,
[ 26] = KO, ['E'] = 4, ['p'] = 41, [155] = KO, [198] = KO, [241] = KO,
[ 27] = KO, ['F'] = 5, ['q'] = 42, [156] = KO, [199] = KO, [242] = KO,
[ 28] = KO, ['G'] = 6, ['r'] = 43, [157] = KO, [200] = KO, [243] = KO,
[ 29] = KO, ['H'] = 7, ['s'] = 44, [158] = KO, [201] = KO, [244] = KO,
[ 30] = KO, ['I'] = 8, ['t'] = 45, [159] = KO, [202] = KO, [245] = KO,
[ 31] = KO, ['J'] = 9, ['u'] = 46, [160] = KO, [203] = KO, [246] = KO,
[ 32] = KO, ['K'] = 10, ['v'] = 47, [161] = KO, [204] = KO, [247] = KO,
[ 33] = KO, ['L'] = 11, ['w'] = 48, [162] = KO, [205] = KO, [248] = KO,
[ 34] = KO, ['M'] = 12, ['x'] = 49, [163] = KO, [206] = KO, [249] = KO,
[ 35] = KO, ['N'] = 13, ['y'] = 50, [164] = KO, [207] = KO, [250] = KO,
[ 36] = KO, ['O'] = 14, ['z'] = 51, [165] = KO, [208] = KO, [251] = KO,
[ 37] = KO, ['P'] = 15, [123] = KO, [166] = KO, [209] = KO, [252] = KO,
[ 38] = KO, ['Q'] = 16, [124] = KO, [167] = KO, [210] = KO, [253] = KO,
[ 39] = KO, ['R'] = 17, [125] = KO, [168] = KO, [211] = KO, [254] = KO,
[ 40] = KO, ['S'] = 18, [126] = KO, [169] = KO, [212] = KO, [255] = KO,
[ 41] = KO, ['T'] = 19, [127] = KO, [170] = KO, [213] = KO,
[ 42] = KO, ['U'] = 20, [128] = KO, [171] = KO, [214] = KO,
};
int32_t kr_base64_encode(const uint8_t *in,
const uint32_t in_len,
uint8_t *out,
const uint32_t out_len)
{
// Checking inputs.
if (in == NULL || out == NULL) {
return KNOT_EINVAL;
}
if (in_len > MAX_BIN_DATA_LEN || out_len < ((in_len + 2) / 3) * 4) {
return KNOT_ERANGE;
}
uint8_t rest_len = in_len % 3;
const uint8_t *stop = in + in_len - rest_len;
uint8_t *text = out;
// Encoding loop takes 3 bytes and creates 4 characters.
while (in < stop) {
text[0] = base64_enc[in[0] >> 2];
text[1] = base64_enc[(in[0] & 0x03) << 4 | in[1] >> 4];
text[2] = base64_enc[(in[1] & 0x0F) << 2 | in[2] >> 6];
text[3] = base64_enc[in[2] & 0x3F];
text += 4;
in += 3;
}
// Processing of padding, if any.
switch (rest_len) {
case 2:
text[0] = base64_enc[in[0] >> 2];
text[1] = base64_enc[(in[0] & 0x03) << 4 | in[1] >> 4];
text[2] = base64_enc[(in[1] & 0x0F) << 2];
text[3] = base64_pad;
text += 4;
break;
case 1:
text[0] = base64_enc[in[0] >> 2];
text[1] = base64_enc[(in[0] & 0x03) << 4];
text[2] = base64_pad;
text[3] = base64_pad;
text += 4;
break;
}
return (text - out);
}
int32_t kr_base64_encode_alloc(const uint8_t *in,
const uint32_t in_len,
uint8_t **out)
{
// Checking inputs.
if (out == NULL) {
return KNOT_EINVAL;
}
if (in_len > MAX_BIN_DATA_LEN) {
return KNOT_ERANGE;
}
// Compute output buffer length.
uint32_t out_len = ((in_len + 2) / 3) * 4;
// Allocate output buffer.
*out = malloc(out_len);
if (*out == NULL) {
return KNOT_ENOMEM;
}
// Encode data.
int32_t ret = kr_base64_encode(in, in_len, *out, out_len);
if (ret < 0) {
free(*out);
*out = NULL;
}
return ret;
}
int32_t kr_base64_decode(const uint8_t *in,
const uint32_t in_len,
uint8_t *out,
const uint32_t out_len)
{
// Checking inputs.
if (in == NULL || out == NULL) {
return KNOT_EINVAL;
}
if (in_len > INT32_MAX || out_len < ((in_len + 3) / 4) * 3) {
return KNOT_ERANGE;
}
if ((in_len % 4) != 0) {
return KNOT_BASE64_ESIZE;
}
const uint8_t *stop = in + in_len;
uint8_t *bin = out;
uint8_t pad_len = 0;
uint8_t c1, c2, c3, c4;
// Decoding loop takes 4 characters and creates 3 bytes.
while (in < stop) {
// Filling and transforming 4 Base64 chars.
c1 = base64_dec[in[0]];
c2 = base64_dec[in[1]];
c3 = base64_dec[in[2]];
c4 = base64_dec[in[3]];
// Check 4. char if is bad or padding.
if (c4 >= PD) {
if (c4 == PD && pad_len == 0) {
pad_len = 1;
} else {
return KNOT_BASE64_ECHAR;
}
}
// Check 3. char if is bad or padding.
if (c3 >= PD) {
if (c3 == PD && pad_len == 1) {
pad_len = 2;
} else {
return KNOT_BASE64_ECHAR;
}
}
// Check 1. and 2. chars if are not padding.
if (c2 >= PD || c1 >= PD) {
return KNOT_BASE64_ECHAR;
}
// Computing of output data based on padding length.
switch (pad_len) {
case 0:
bin[2] = (c3 << 6) + c4;
// FALLTHROUGH
case 1:
bin[1] = (c2 << 4) + (c3 >> 2);
// FALLTHROUGH
case 2:
bin[0] = (c1 << 2) + (c2 >> 4);
}
// Update output end.
switch (pad_len) {
case 0:
bin += 3;
break;
case 1:
bin += 2;
break;
case 2:
bin += 1;
break;
}
in += 4;
}
return (bin - out);
}
int32_t kr_base64_decode_alloc(const uint8_t *in,
const uint32_t in_len,
uint8_t **out)
{
// Checking inputs.
if (out == NULL) {
return KNOT_EINVAL;
}
// Compute output buffer length.
uint32_t out_len = ((in_len + 3) / 4) * 3;
// Allocate output buffer.
*out = malloc(out_len);
if (*out == NULL) {
return KNOT_ENOMEM;
}
// Decode data.
int32_t ret = kr_base64_decode(in, in_len, *out, out_len);
if (ret < 0) {
free(*out);
*out = NULL;
}
return ret;
}
|
