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ac8802eb | 1 | /* $OpenBSD: base64.c,v 1.4 2002/01/02 23:00:10 deraadt Exp $ */ |
1d1ffb87 | 2 | |
3 | /* | |
4 | * Copyright (c) 1996 by Internet Software Consortium. | |
5 | * | |
6 | * Permission to use, copy, modify, and 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS | |
11 | * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES | |
12 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE | |
13 | * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL | |
14 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR | |
15 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS | |
16 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS | |
17 | * SOFTWARE. | |
18 | */ | |
19 | ||
20 | /* | |
21 | * Portions Copyright (c) 1995 by International Business Machines, Inc. | |
22 | * | |
23 | * International Business Machines, Inc. (hereinafter called IBM) grants | |
24 | * permission under its copyrights to use, copy, modify, and distribute this | |
25 | * Software with or without fee, provided that the above copyright notice and | |
26 | * all paragraphs of this notice appear in all copies, and that the name of IBM | |
27 | * not be used in connection with the marketing of any product incorporating | |
28 | * the Software or modifications thereof, without specific, written prior | |
29 | * permission. | |
30 | * | |
31 | * To the extent it has a right to do so, IBM grants an immunity from suit | |
32 | * under its patents, if any, for the use, sale or manufacture of products to | |
33 | * the extent that such products are used for performing Domain Name System | |
34 | * dynamic updates in TCP/IP networks by means of the Software. No immunity is | |
35 | * granted for any product per se or for any other function of any product. | |
36 | * | |
37 | * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES, | |
38 | * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A | |
39 | * PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL, | |
40 | * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING | |
41 | * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN | |
42 | * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES. | |
43 | */ | |
44 | ||
f6d4fb87 | 45 | /* OPENBSD ORIGINAL: lib/libc/net/base64.c */ |
46 | ||
17962c40 | 47 | #include "includes.h" |
1d1ffb87 | 48 | |
19160674 | 49 | #if (!defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP)) || (!defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON)) |
1d1ffb87 | 50 | |
51 | #include <sys/types.h> | |
52 | #include <sys/param.h> | |
53 | #include <sys/socket.h> | |
54 | #include <netinet/in.h> | |
55 | #include <arpa/inet.h> | |
56 | ||
57 | #include <ctype.h> | |
1d1ffb87 | 58 | #include <stdio.h> |
59 | ||
60 | #include <stdlib.h> | |
61 | #include <string.h> | |
62 | ||
9c8dbb1b | 63 | #include "base64.h" |
eba02c94 | 64 | |
ac8802eb | 65 | /* XXX abort illegal in library */ |
1d1ffb87 | 66 | #define Assert(Cond) if (!(Cond)) abort() |
67 | ||
68 | static const char Base64[] = | |
69 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; | |
70 | static const char Pad64 = '='; | |
71 | ||
72 | /* (From RFC1521 and draft-ietf-dnssec-secext-03.txt) | |
73 | The following encoding technique is taken from RFC 1521 by Borenstein | |
74 | and Freed. It is reproduced here in a slightly edited form for | |
75 | convenience. | |
76 | ||
77 | A 65-character subset of US-ASCII is used, enabling 6 bits to be | |
78 | represented per printable character. (The extra 65th character, "=", | |
79 | is used to signify a special processing function.) | |
80 | ||
81 | The encoding process represents 24-bit groups of input bits as output | |
82 | strings of 4 encoded characters. Proceeding from left to right, a | |
83 | 24-bit input group is formed by concatenating 3 8-bit input groups. | |
84 | These 24 bits are then treated as 4 concatenated 6-bit groups, each | |
85 | of which is translated into a single digit in the base64 alphabet. | |
86 | ||
87 | Each 6-bit group is used as an index into an array of 64 printable | |
88 | characters. The character referenced by the index is placed in the | |
89 | output string. | |
90 | ||
91 | Table 1: The Base64 Alphabet | |
92 | ||
93 | Value Encoding Value Encoding Value Encoding Value Encoding | |
94 | 0 A 17 R 34 i 51 z | |
95 | 1 B 18 S 35 j 52 0 | |
96 | 2 C 19 T 36 k 53 1 | |
97 | 3 D 20 U 37 l 54 2 | |
98 | 4 E 21 V 38 m 55 3 | |
99 | 5 F 22 W 39 n 56 4 | |
100 | 6 G 23 X 40 o 57 5 | |
101 | 7 H 24 Y 41 p 58 6 | |
102 | 8 I 25 Z 42 q 59 7 | |
103 | 9 J 26 a 43 r 60 8 | |
104 | 10 K 27 b 44 s 61 9 | |
105 | 11 L 28 c 45 t 62 + | |
106 | 12 M 29 d 46 u 63 / | |
107 | 13 N 30 e 47 v | |
108 | 14 O 31 f 48 w (pad) = | |
109 | 15 P 32 g 49 x | |
110 | 16 Q 33 h 50 y | |
111 | ||
112 | Special processing is performed if fewer than 24 bits are available | |
113 | at the end of the data being encoded. A full encoding quantum is | |
114 | always completed at the end of a quantity. When fewer than 24 input | |
115 | bits are available in an input group, zero bits are added (on the | |
116 | right) to form an integral number of 6-bit groups. Padding at the | |
117 | end of the data is performed using the '=' character. | |
118 | ||
119 | Since all base64 input is an integral number of octets, only the | |
120 | ------------------------------------------------- | |
121 | following cases can arise: | |
122 | ||
123 | (1) the final quantum of encoding input is an integral | |
124 | multiple of 24 bits; here, the final unit of encoded | |
125 | output will be an integral multiple of 4 characters | |
126 | with no "=" padding, | |
127 | (2) the final quantum of encoding input is exactly 8 bits; | |
128 | here, the final unit of encoded output will be two | |
129 | characters followed by two "=" padding characters, or | |
130 | (3) the final quantum of encoding input is exactly 16 bits; | |
131 | here, the final unit of encoded output will be three | |
132 | characters followed by one "=" padding character. | |
133 | */ | |
134 | ||
19160674 | 135 | #if !defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP) |
1d1ffb87 | 136 | int |
137 | b64_ntop(u_char const *src, size_t srclength, char *target, size_t targsize) | |
138 | { | |
139 | size_t datalength = 0; | |
140 | u_char input[3]; | |
141 | u_char output[4]; | |
3e6325a6 | 142 | u_int i; |
1d1ffb87 | 143 | |
144 | while (2 < srclength) { | |
145 | input[0] = *src++; | |
146 | input[1] = *src++; | |
147 | input[2] = *src++; | |
148 | srclength -= 3; | |
149 | ||
150 | output[0] = input[0] >> 2; | |
151 | output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); | |
152 | output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); | |
153 | output[3] = input[2] & 0x3f; | |
154 | Assert(output[0] < 64); | |
155 | Assert(output[1] < 64); | |
156 | Assert(output[2] < 64); | |
157 | Assert(output[3] < 64); | |
158 | ||
159 | if (datalength + 4 > targsize) | |
160 | return (-1); | |
161 | target[datalength++] = Base64[output[0]]; | |
162 | target[datalength++] = Base64[output[1]]; | |
163 | target[datalength++] = Base64[output[2]]; | |
164 | target[datalength++] = Base64[output[3]]; | |
165 | } | |
166 | ||
167 | /* Now we worry about padding. */ | |
168 | if (0 != srclength) { | |
169 | /* Get what's left. */ | |
170 | input[0] = input[1] = input[2] = '\0'; | |
171 | for (i = 0; i < srclength; i++) | |
172 | input[i] = *src++; | |
173 | ||
174 | output[0] = input[0] >> 2; | |
175 | output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); | |
176 | output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); | |
177 | Assert(output[0] < 64); | |
178 | Assert(output[1] < 64); | |
179 | Assert(output[2] < 64); | |
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 | } | |
19160674 | 196 | #endif /* !defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP) */ |
197 | ||
198 | #if !defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON) | |
1d1ffb87 | 199 | |
200 | /* skips all whitespace anywhere. | |
201 | converts characters, four at a time, starting at (or after) | |
202 | src from base - 64 numbers into three 8 bit bytes in the target area. | |
203 | it returns the number of data bytes stored at the target, or -1 on error. | |
204 | */ | |
205 | ||
206 | int | |
207 | b64_pton(char const *src, u_char *target, size_t targsize) | |
208 | { | |
3e6325a6 | 209 | u_int tarindex, state; |
210 | int ch; | |
1d1ffb87 | 211 | char *pos; |
212 | ||
213 | state = 0; | |
214 | tarindex = 0; | |
215 | ||
216 | while ((ch = *src++) != '\0') { | |
217 | if (isspace(ch)) /* Skip whitespace anywhere. */ | |
218 | continue; | |
219 | ||
220 | if (ch == Pad64) | |
221 | break; | |
222 | ||
223 | pos = strchr(Base64, ch); | |
224 | if (pos == 0) /* A non-base64 character. */ | |
225 | return (-1); | |
226 | ||
227 | switch (state) { | |
228 | case 0: | |
229 | if (target) { | |
230 | if (tarindex >= targsize) | |
231 | return (-1); | |
232 | target[tarindex] = (pos - Base64) << 2; | |
233 | } | |
234 | state = 1; | |
235 | break; | |
236 | case 1: | |
237 | if (target) { | |
238 | if (tarindex + 1 >= targsize) | |
239 | return (-1); | |
240 | target[tarindex] |= (pos - Base64) >> 4; | |
241 | target[tarindex+1] = ((pos - Base64) & 0x0f) | |
242 | << 4 ; | |
243 | } | |
244 | tarindex++; | |
245 | state = 2; | |
246 | break; | |
247 | case 2: | |
248 | if (target) { | |
249 | if (tarindex + 1 >= targsize) | |
250 | return (-1); | |
251 | target[tarindex] |= (pos - Base64) >> 2; | |
252 | target[tarindex+1] = ((pos - Base64) & 0x03) | |
253 | << 6; | |
254 | } | |
255 | tarindex++; | |
256 | state = 3; | |
257 | break; | |
258 | case 3: | |
259 | if (target) { | |
260 | if (tarindex >= targsize) | |
261 | return (-1); | |
262 | target[tarindex] |= (pos - Base64); | |
263 | } | |
264 | tarindex++; | |
265 | state = 0; | |
266 | break; | |
267 | } | |
268 | } | |
269 | ||
270 | /* | |
271 | * We are done decoding Base-64 chars. Let's see if we ended | |
272 | * on a byte boundary, and/or with erroneous trailing characters. | |
273 | */ | |
274 | ||
275 | if (ch == Pad64) { /* We got a pad char. */ | |
276 | ch = *src++; /* Skip it, get next. */ | |
277 | switch (state) { | |
278 | case 0: /* Invalid = in first position */ | |
279 | case 1: /* Invalid = in second position */ | |
280 | return (-1); | |
281 | ||
282 | case 2: /* Valid, means one byte of info */ | |
283 | /* Skip any number of spaces. */ | |
284 | for (; ch != '\0'; ch = *src++) | |
285 | if (!isspace(ch)) | |
286 | break; | |
287 | /* Make sure there is another trailing = sign. */ | |
288 | if (ch != Pad64) | |
289 | return (-1); | |
290 | ch = *src++; /* Skip the = */ | |
291 | /* Fall through to "single trailing =" case. */ | |
292 | /* FALLTHROUGH */ | |
293 | ||
294 | case 3: /* Valid, means two bytes of info */ | |
295 | /* | |
296 | * We know this char is an =. Is there anything but | |
297 | * whitespace after it? | |
298 | */ | |
299 | for (; ch != '\0'; ch = *src++) | |
300 | if (!isspace(ch)) | |
301 | return (-1); | |
302 | ||
303 | /* | |
304 | * Now make sure for cases 2 and 3 that the "extra" | |
305 | * bits that slopped past the last full byte were | |
306 | * zeros. If we don't check them, they become a | |
307 | * subliminal channel. | |
308 | */ | |
309 | if (target && target[tarindex] != 0) | |
310 | return (-1); | |
311 | } | |
312 | } else { | |
313 | /* | |
314 | * We ended by seeing the end of the string. Make sure we | |
315 | * have no partial bytes lying around. | |
316 | */ | |
317 | if (state != 0) | |
318 | return (-1); | |
319 | } | |
320 | ||
321 | return (tarindex); | |
322 | } | |
323 | ||
19160674 | 324 | #endif /* !defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON) */ |
325 | #endif |