libubox: tests: add more blobmsg/json test cases
[project/libubox.git] / base64.c
1 /*
2 * base64 - libubox base64 functions
3 *
4 * Copyright (C) 2015 Felix Fietkau <nbd@openwrt.org>
5 *
6 * Permission to use, copy, modify, and/or distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 /* $OpenBSD: base64.c,v 1.7 2013/12/31 02:32:56 tedu Exp $ */
20
21 /*
22 * Copyright (c) 1996 by Internet Software Consortium.
23 *
24 * Permission to use, copy, modify, and distribute this software for any
25 * purpose with or without fee is hereby granted, provided that the above
26 * copyright notice and this permission notice appear in all copies.
27 *
28 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
29 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
30 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
31 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
32 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
33 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
34 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
35 * SOFTWARE.
36 */
37
38 /*
39 * Portions Copyright (c) 1995 by International Business Machines, Inc.
40 *
41 * International Business Machines, Inc. (hereinafter called IBM) grants
42 * permission under its copyrights to use, copy, modify, and distribute this
43 * Software with or without fee, provided that the above copyright notice and
44 * all paragraphs of this notice appear in all copies, and that the name of IBM
45 * not be used in connection with the marketing of any product incorporating
46 * the Software or modifications thereof, without specific, written prior
47 * permission.
48 *
49 * To the extent it has a right to do so, IBM grants an immunity from suit
50 * under its patents, if any, for the use, sale or manufacture of products to
51 * the extent that such products are used for performing Domain Name System
52 * dynamic updates in TCP/IP networks by means of the Software. No immunity is
53 * granted for any product per se or for any other function of any product.
54 *
55 * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES,
56 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
57 * PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL,
58 * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING
59 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN
60 * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES.
61 */
62
63 #include <sys/types.h>
64 #include <ctype.h>
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <string.h>
68
69 #include "assert.h"
70 #include "utils.h"
71
72 static const char Base64[] =
73 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
74 static const char Pad64 = '=';
75
76 /* (From RFC1521 and draft-ietf-dnssec-secext-03.txt)
77 The following encoding technique is taken from RFC 1521 by Borenstein
78 and Freed. It is reproduced here in a slightly edited form for
79 convenience.
80
81 A 65-character subset of US-ASCII is used, enabling 6 bits to be
82 represented per printable character. (The extra 65th character, "=",
83 is used to signify a special processing function.)
84
85 The encoding process represents 24-bit groups of input bits as output
86 strings of 4 encoded characters. Proceeding from left to right, a
87 24-bit input group is formed by concatenating 3 8-bit input groups.
88 These 24 bits are then treated as 4 concatenated 6-bit groups, each
89 of which is translated into a single digit in the base64 alphabet.
90
91 Each 6-bit group is used as an index into an array of 64 printable
92 characters. The character referenced by the index is placed in the
93 output string.
94
95 Table 1: The Base64 Alphabet
96
97 Value Encoding Value Encoding Value Encoding Value Encoding
98 0 A 17 R 34 i 51 z
99 1 B 18 S 35 j 52 0
100 2 C 19 T 36 k 53 1
101 3 D 20 U 37 l 54 2
102 4 E 21 V 38 m 55 3
103 5 F 22 W 39 n 56 4
104 6 G 23 X 40 o 57 5
105 7 H 24 Y 41 p 58 6
106 8 I 25 Z 42 q 59 7
107 9 J 26 a 43 r 60 8
108 10 K 27 b 44 s 61 9
109 11 L 28 c 45 t 62 +
110 12 M 29 d 46 u 63 /
111 13 N 30 e 47 v
112 14 O 31 f 48 w (pad) =
113 15 P 32 g 49 x
114 16 Q 33 h 50 y
115
116 Special processing is performed if fewer than 24 bits are available
117 at the end of the data being encoded. A full encoding quantum is
118 always completed at the end of a quantity. When fewer than 24 input
119 bits are available in an input group, zero bits are added (on the
120 right) to form an integral number of 6-bit groups. Padding at the
121 end of the data is performed using the '=' character.
122
123 Since all base64 input is an integral number of octets, only the
124 -------------------------------------------------
125 following cases can arise:
126
127 (1) the final quantum of encoding input is an integral
128 multiple of 24 bits; here, the final unit of encoded
129 output will be an integral multiple of 4 characters
130 with no "=" padding,
131 (2) the final quantum of encoding input is exactly 8 bits;
132 here, the final unit of encoded output will be two
133 characters followed by two "=" padding characters, or
134 (3) the final quantum of encoding input is exactly 16 bits;
135 here, the final unit of encoded output will be three
136 characters followed by one "=" padding character.
137 */
138
139 int b64_encode(const void *_src, size_t srclength,
140 void *dest, size_t targsize)
141 {
142 const unsigned char *src = _src;
143 char *target = dest;
144 size_t datalength = 0;
145 u_char input[3] = {0};
146 u_char output[4];
147 size_t i;
148
149 assert(dest && targsize > 0);
150
151 while (2 < srclength) {
152 input[0] = *src++;
153 input[1] = *src++;
154 input[2] = *src++;
155 srclength -= 3;
156
157 output[0] = input[0] >> 2;
158 output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
159 output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
160 output[3] = input[2] & 0x3f;
161
162 if (datalength + 4 > targsize)
163 return (-1);
164 target[datalength++] = Base64[output[0]];
165 target[datalength++] = Base64[output[1]];
166 target[datalength++] = Base64[output[2]];
167 target[datalength++] = Base64[output[3]];
168 }
169
170 /* Now we worry about padding. */
171 if (0 != srclength) {
172 /* Get what's left. */
173 input[0] = input[1] = input[2] = '\0';
174 for (i = 0; i < srclength; i++)
175 input[i] = *src++;
176
177 output[0] = input[0] >> 2;
178 output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
179 output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
180
181 if (datalength + 4 > targsize)
182 return (-1);
183 target[datalength++] = Base64[output[0]];
184 target[datalength++] = Base64[output[1]];
185 if (srclength == 1)
186 target[datalength++] = Pad64;
187 else
188 target[datalength++] = Base64[output[2]];
189 target[datalength++] = Pad64;
190 }
191 if (datalength >= targsize)
192 return (-1);
193 target[datalength] = '\0'; /* Returned value doesn't count \0. */
194 return (datalength);
195 }
196
197 /* skips all whitespace anywhere.
198 converts characters, four at a time, starting at (or after)
199 src from base - 64 numbers into three 8 bit bytes in the target area.
200 it returns the number of data bytes stored at the target, or -1 on error.
201 */
202
203 int b64_decode(const void *_src, void *dest, size_t targsize)
204 {
205 const char *src = _src;
206 unsigned char *target = dest;
207 int state, ch;
208 size_t tarindex;
209 u_char nextbyte;
210 char *pos;
211
212 state = 0;
213 tarindex = 0;
214
215 assert(dest && targsize > 0);
216
217 while ((ch = (unsigned char)*src++) != '\0') {
218 if (isspace(ch)) /* Skip whitespace anywhere. */
219 continue;
220
221 if (ch == Pad64)
222 break;
223
224 pos = strchr(Base64, ch);
225 if (pos == 0) /* A non-base64 character. */
226 return (-1);
227
228 switch (state) {
229 case 0:
230 if (target) {
231 if (tarindex >= targsize)
232 return (-1);
233 target[tarindex] = (pos - Base64) << 2;
234 }
235 state = 1;
236 break;
237 case 1:
238 if (target) {
239 if (tarindex >= targsize)
240 return (-1);
241 target[tarindex] |= (pos - Base64) >> 4;
242 nextbyte = ((pos - Base64) & 0x0f) << 4;
243 if (tarindex + 1 < targsize)
244 target[tarindex+1] = nextbyte;
245 else if (nextbyte)
246 return (-1);
247 }
248 tarindex++;
249 state = 2;
250 break;
251 case 2:
252 if (target) {
253 if (tarindex >= targsize)
254 return (-1);
255 target[tarindex] |= (pos - Base64) >> 2;
256 nextbyte = ((pos - Base64) & 0x03) << 6;
257 if (tarindex + 1 < targsize)
258 target[tarindex+1] = nextbyte;
259 else if (nextbyte)
260 return (-1);
261 }
262 tarindex++;
263 state = 3;
264 break;
265 case 3:
266 if (target) {
267 if (tarindex >= targsize)
268 return (-1);
269 target[tarindex] |= (pos - Base64);
270 }
271 tarindex++;
272 state = 0;
273 break;
274 }
275 }
276
277 /*
278 * We are done decoding Base-64 chars. Let's see if we ended
279 * on a byte boundary, and/or with erroneous trailing characters.
280 */
281
282 if (ch == Pad64) { /* We got a pad char. */
283 ch = (unsigned char)*src++; /* Skip it, get next. */
284 switch (state) {
285 case 0: /* Invalid = in first position */
286 case 1: /* Invalid = in second position */
287 return (-1);
288
289 case 2: /* Valid, means one byte of info */
290 /* Skip any number of spaces. */
291 for (; ch != '\0'; ch = (unsigned char)*src++)
292 if (!isspace(ch))
293 break;
294 /* Make sure there is another trailing = sign. */
295 if (ch != Pad64)
296 return (-1);
297 ch = (unsigned char)*src++; /* Skip the = */
298 /* Fall through to "single trailing =" case. */
299 /* FALLTHROUGH */
300
301 case 3: /* Valid, means two bytes of info */
302 /*
303 * We know this char is an =. Is there anything but
304 * whitespace after it?
305 */
306 for (; ch != '\0'; ch = (unsigned char)*src++)
307 if (!isspace(ch))
308 return (-1);
309
310 /*
311 * Now make sure for cases 2 and 3 that the "extra"
312 * bits that slopped past the last full byte were
313 * zeros. If we don't check them, they become a
314 * subliminal channel.
315 */
316 if (target && tarindex < targsize &&
317 target[tarindex] != 0)
318 return (-1);
319 }
320 } else {
321 /*
322 * We ended by seeing the end of the string. Make sure we
323 * have no partial bytes lying around.
324 */
325 if (state != 0)
326 return (-1);
327 }
328
329 /* Null-terminate if we have room left */
330 if (tarindex < targsize)
331 target[tarindex] = 0;
332
333 return (tarindex);
334 }