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Diffstat (limited to 'sway/base64.c')
-rw-r--r-- | sway/base64.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/sway/base64.c b/sway/base64.c new file mode 100644 index 00000000..0d51b5c7 --- /dev/null +++ b/sway/base64.c | |||
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1 | /* | ||
2 | * Adapted from https://github.com/littlstar/b64.c | ||
3 | * License under the MIT License: | ||
4 | * Copyright (c) 2014 Little Star Media, Inc. | ||
5 | * | ||
6 | * Permission is hereby granted, free of charge, to any person obtaining a copy | ||
7 | * of this software and associated documentation files (the "Software"), to deal | ||
8 | * in the Software without restriction, including without limitation the rights | ||
9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | ||
10 | * copies of the Software, and to permit persons to whom the Software is | ||
11 | * furnished to do so, subject to the following conditions: | ||
12 | * | ||
13 | * The above copyright notice and this permission notice shall be included in all | ||
14 | * copies or substantial portions of the Software. | ||
15 | * | ||
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | ||
17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | ||
18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | ||
19 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | ||
20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | ||
21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | ||
22 | * SOFTWARE. | ||
23 | */ | ||
24 | |||
25 | #include <ctype.h> | ||
26 | #include <stdlib.h> | ||
27 | #include "util.h" | ||
28 | |||
29 | static const char b64_table[] = { | ||
30 | 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', | ||
31 | 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', | ||
32 | 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', | ||
33 | 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', | ||
34 | 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', | ||
35 | 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', | ||
36 | 'w', 'x', 'y', 'z', '0', '1', '2', '3', | ||
37 | '4', '5', '6', '7', '8', '9', '+', '/' | ||
38 | }; | ||
39 | |||
40 | char *b64_encode(const char *src, size_t len, size_t *flen) { | ||
41 | int i = 0; | ||
42 | int j = 0; | ||
43 | char *enc = NULL; | ||
44 | size_t size = len * 4 / 3; | ||
45 | size_t idx = 0; | ||
46 | unsigned char buf[4]; | ||
47 | char tmp[3]; | ||
48 | |||
49 | // alloc | ||
50 | enc = (char *) malloc(size + 1); | ||
51 | if (NULL == enc) { return NULL; } | ||
52 | |||
53 | // parse until end of source | ||
54 | while (len--) { | ||
55 | // read up to 3 bytes at a time into `tmp' | ||
56 | tmp[i++] = *(src++); | ||
57 | |||
58 | // if 3 bytes read then encode into `buf' | ||
59 | if (3 == i) { | ||
60 | buf[0] = (tmp[0] & 0xfc) >> 2; | ||
61 | buf[1] = ((tmp[0] & 0x03) << 4) + ((tmp[1] & 0xf0) >> 4); | ||
62 | buf[2] = ((tmp[1] & 0x0f) << 2) + ((tmp[2] & 0xc0) >> 6); | ||
63 | buf[3] = tmp[2] & 0x3f; | ||
64 | |||
65 | // shouldn't really happen | ||
66 | if (idx + 4 > size) { | ||
67 | size += 16; | ||
68 | enc = (char *) realloc(enc, size + 1); | ||
69 | } | ||
70 | for (i = 0; i < 4; ++i) { | ||
71 | enc[idx++] = b64_table[buf[i]]; | ||
72 | } | ||
73 | |||
74 | // reset index | ||
75 | i = 0; | ||
76 | } | ||
77 | } | ||
78 | |||
79 | // remainder | ||
80 | if (i > 0) { | ||
81 | // fill `tmp' with `\0' at most 3 times | ||
82 | for (j = i; j < 3; ++j) { | ||
83 | tmp[j] = '\0'; | ||
84 | } | ||
85 | |||
86 | // perform same codec as above | ||
87 | buf[0] = (tmp[0] & 0xfc) >> 2; | ||
88 | buf[1] = ((tmp[0] & 0x03) << 4) + ((tmp[1] & 0xf0) >> 4); | ||
89 | buf[2] = ((tmp[1] & 0x0f) << 2) + ((tmp[2] & 0xc0) >> 6); | ||
90 | buf[3] = tmp[2] & 0x3f; | ||
91 | |||
92 | // perform same write to `enc` with new allocation | ||
93 | size_t delta = (i > 3 ? 0 : 3 - i) + (j > i + 1 ? 0 : i + 1 - j); | ||
94 | if (idx + delta > size) { | ||
95 | size += delta; | ||
96 | enc = (char *) realloc(enc, size + 1); | ||
97 | } | ||
98 | for (j = 0; (j < i + 1); ++j) { | ||
99 | enc[idx++] = b64_table[buf[j]]; | ||
100 | } | ||
101 | |||
102 | // while there is still a remainder | ||
103 | // append `=' to `enc' | ||
104 | while ((i++ < 3)) { | ||
105 | enc[idx++] = '='; | ||
106 | } | ||
107 | } | ||
108 | |||
109 | enc[idx] = '\0'; | ||
110 | |||
111 | if (flen) | ||
112 | *flen = size; | ||
113 | return enc; | ||
114 | } | ||
115 | |||
116 | unsigned char *b64_decode(const char *src, size_t len, size_t *decsize) { | ||
117 | int i = 0; | ||
118 | int j = 0; | ||
119 | int l = 0; | ||
120 | // max size estimate | ||
121 | size_t size = len * 3 / 4; | ||
122 | size_t idx = 0; | ||
123 | unsigned char *dec = NULL; | ||
124 | unsigned char buf[3]; | ||
125 | unsigned char tmp[4]; | ||
126 | |||
127 | // alloc | ||
128 | dec = (unsigned char *) malloc(size + 1); | ||
129 | if (NULL == dec) { return NULL; } | ||
130 | |||
131 | // parse until end of source | ||
132 | while (len--) { | ||
133 | if (isspace(src[j])) { j++; continue; } | ||
134 | // break if char is `=' or not base64 char | ||
135 | if ('=' == src[j]) { break; } | ||
136 | if (!(isalnum(src[j]) || '+' == src[j] || '/' == src[j])) { break; } | ||
137 | |||
138 | // read up to 4 bytes at a time into `tmp' | ||
139 | tmp[i++] = src[j++]; | ||
140 | |||
141 | // if 4 bytes read then decode into `buf' | ||
142 | if (4 == i) { | ||
143 | // translate values in `tmp' from table | ||
144 | for (i = 0; i < 4; ++i) { | ||
145 | // find translation char in `b64_table' | ||
146 | for (l = 0; l < 64; ++l) { | ||
147 | if (tmp[i] == b64_table[l]) { | ||
148 | tmp[i] = l; | ||
149 | break; | ||
150 | } | ||
151 | } | ||
152 | } | ||
153 | |||
154 | // decode | ||
155 | buf[0] = (tmp[0] << 2) + ((tmp[1] & 0x30) >> 4); | ||
156 | buf[1] = ((tmp[1] & 0xf) << 4) + ((tmp[2] & 0x3c) >> 2); | ||
157 | buf[2] = ((tmp[2] & 0x3) << 6) + tmp[3]; | ||
158 | |||
159 | // unlikely | ||
160 | if (idx + 3 > size) { | ||
161 | size += 16; | ||
162 | dec = (unsigned char *) realloc(dec, size + 1); | ||
163 | } | ||
164 | if (dec != NULL){ | ||
165 | for (i = 0; i < 3; ++i) { | ||
166 | dec[idx++] = buf[i]; | ||
167 | } | ||
168 | } else { | ||
169 | return NULL; | ||
170 | } | ||
171 | |||
172 | // reset | ||
173 | i = 0; | ||
174 | } | ||
175 | } | ||
176 | |||
177 | // remainder | ||
178 | if (i > 0) { | ||
179 | // fill `tmp' with `\0' at most 4 times | ||
180 | for (j = i; j < 4; ++j) { | ||
181 | tmp[j] = '\0'; | ||
182 | } | ||
183 | |||
184 | // translate remainder | ||
185 | for (j = 0; j < 4; ++j) { | ||
186 | // find translation char in `b64_table' | ||
187 | for (l = 0; l < 64; ++l) { | ||
188 | if (tmp[j] == b64_table[l]) { | ||
189 | tmp[j] = l; | ||
190 | break; | ||
191 | } | ||
192 | } | ||
193 | } | ||
194 | |||
195 | // decode remainder | ||
196 | buf[0] = (tmp[0] << 2) + ((tmp[1] & 0x30) >> 4); | ||
197 | buf[1] = ((tmp[1] & 0xf) << 4) + ((tmp[2] & 0x3c) >> 2); | ||
198 | buf[2] = ((tmp[2] & 0x3) << 6) + tmp[3]; | ||
199 | |||
200 | // write remainer decoded buffer to `dec' | ||
201 | if (idx + (i - 1) > size) { | ||
202 | size += 16; | ||
203 | dec = (unsigned char *) realloc(dec, size + 1); | ||
204 | } | ||
205 | if (dec != NULL){ | ||
206 | for (j = 0; (j < i - 1); ++j) { | ||
207 | dec[idx++] = buf[j]; | ||
208 | } | ||
209 | } else { | ||
210 | return NULL; | ||
211 | } | ||
212 | } | ||
213 | |||
214 | dec[idx] = '\0'; | ||
215 | // Return back the size of decoded string if demanded. | ||
216 | if (decsize != NULL) { | ||
217 | *decsize = size; | ||
218 | } | ||
219 | |||
220 | return dec; | ||
221 | } | ||