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df21c858 | 1 | /* |
e685e07d | 2 | * Copyright (c) 1996-1999 by Internet Software Consortium. |
df21c858 UD |
3 | * |
4 | * Permission to use, copy, modify, and distribute this software for any | |
5 | * purpose with or without fee is hereby granted, provided that the above | |
6 | * copyright notice and this permission notice appear in all copies. | |
7 | * | |
8 | * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS | |
9 | * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES | |
10 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE | |
11 | * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL | |
12 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR | |
13 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS | |
14 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS | |
15 | * SOFTWARE. | |
16 | */ | |
17 | ||
18 | /* | |
19 | * Portions Copyright (c) 1995 by International Business Machines, Inc. | |
20 | * | |
21 | * International Business Machines, Inc. (hereinafter called IBM) grants | |
22 | * permission under its copyrights to use, copy, modify, and distribute this | |
23 | * Software with or without fee, provided that the above copyright notice and | |
24 | * all paragraphs of this notice appear in all copies, and that the name of IBM | |
25 | * not be used in connection with the marketing of any product incorporating | |
26 | * the Software or modifications thereof, without specific, written prior | |
27 | * permission. | |
28 | * | |
29 | * To the extent it has a right to do so, IBM grants an immunity from suit | |
30 | * under its patents, if any, for the use, sale or manufacture of products to | |
31 | * the extent that such products are used for performing Domain Name System | |
32 | * dynamic updates in TCP/IP networks by means of the Software. No immunity is | |
33 | * granted for any product per se or for any other function of any product. | |
34 | * | |
35 | * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES, | |
36 | * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A | |
37 | * PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL, | |
38 | * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING | |
39 | * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN | |
40 | * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES. | |
41 | */ | |
42 | ||
43 | #include <sys/types.h> | |
44 | #include <sys/param.h> | |
45 | #include <sys/socket.h> | |
e685e07d | 46 | |
df21c858 UD |
47 | #include <netinet/in.h> |
48 | #include <arpa/inet.h> | |
49 | #include <arpa/nameser.h> | |
50 | ||
51 | #include <ctype.h> | |
52 | #include <resolv.h> | |
53 | #include <stdio.h> | |
e685e07d UD |
54 | #include <stdlib.h> |
55 | #include <string.h> | |
df21c858 UD |
56 | |
57 | #define Assert(Cond) if (!(Cond)) abort() | |
58 | ||
59 | static const char Base64[] = | |
60 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; | |
61 | static const char Pad64 = '='; | |
62 | ||
63 | /* (From RFC1521 and draft-ietf-dnssec-secext-03.txt) | |
64 | The following encoding technique is taken from RFC 1521 by Borenstein | |
65 | and Freed. It is reproduced here in a slightly edited form for | |
66 | convenience. | |
67 | ||
68 | A 65-character subset of US-ASCII is used, enabling 6 bits to be | |
69 | represented per printable character. (The extra 65th character, "=", | |
70 | is used to signify a special processing function.) | |
71 | ||
72 | The encoding process represents 24-bit groups of input bits as output | |
73 | strings of 4 encoded characters. Proceeding from left to right, a | |
74 | 24-bit input group is formed by concatenating 3 8-bit input groups. | |
75 | These 24 bits are then treated as 4 concatenated 6-bit groups, each | |
76 | of which is translated into a single digit in the base64 alphabet. | |
77 | ||
78 | Each 6-bit group is used as an index into an array of 64 printable | |
79 | characters. The character referenced by the index is placed in the | |
80 | output string. | |
81 | ||
82 | Table 1: The Base64 Alphabet | |
83 | ||
84 | Value Encoding Value Encoding Value Encoding Value Encoding | |
85 | 0 A 17 R 34 i 51 z | |
86 | 1 B 18 S 35 j 52 0 | |
87 | 2 C 19 T 36 k 53 1 | |
88 | 3 D 20 U 37 l 54 2 | |
89 | 4 E 21 V 38 m 55 3 | |
90 | 5 F 22 W 39 n 56 4 | |
91 | 6 G 23 X 40 o 57 5 | |
92 | 7 H 24 Y 41 p 58 6 | |
93 | 8 I 25 Z 42 q 59 7 | |
94 | 9 J 26 a 43 r 60 8 | |
95 | 10 K 27 b 44 s 61 9 | |
96 | 11 L 28 c 45 t 62 + | |
97 | 12 M 29 d 46 u 63 / | |
98 | 13 N 30 e 47 v | |
99 | 14 O 31 f 48 w (pad) = | |
100 | 15 P 32 g 49 x | |
101 | 16 Q 33 h 50 y | |
102 | ||
103 | Special processing is performed if fewer than 24 bits are available | |
104 | at the end of the data being encoded. A full encoding quantum is | |
105 | always completed at the end of a quantity. When fewer than 24 input | |
106 | bits are available in an input group, zero bits are added (on the | |
107 | right) to form an integral number of 6-bit groups. Padding at the | |
108 | end of the data is performed using the '=' character. | |
109 | ||
110 | Since all base64 input is an integral number of octets, only the | |
6f9d8e68 | 111 | ------------------------------------------------- |
df21c858 | 112 | following cases can arise: |
6f9d8e68 | 113 | |
df21c858 UD |
114 | (1) the final quantum of encoding input is an integral |
115 | multiple of 24 bits; here, the final unit of encoded | |
116 | output will be an integral multiple of 4 characters | |
117 | with no "=" padding, | |
118 | (2) the final quantum of encoding input is exactly 8 bits; | |
119 | here, the final unit of encoded output will be two | |
120 | characters followed by two "=" padding characters, or | |
121 | (3) the final quantum of encoding input is exactly 16 bits; | |
122 | here, the final unit of encoded output will be three | |
123 | characters followed by one "=" padding character. | |
124 | */ | |
125 | ||
845dcb57 | 126 | int |
e685e07d | 127 | b64_ntop(u_char const *src, size_t srclength, char *target, size_t targsize) { |
df21c858 UD |
128 | size_t datalength = 0; |
129 | u_char input[3]; | |
130 | u_char output[4]; | |
01c901a5 | 131 | size_t i; |
df21c858 UD |
132 | |
133 | while (2 < srclength) { | |
134 | input[0] = *src++; | |
135 | input[1] = *src++; | |
136 | input[2] = *src++; | |
137 | srclength -= 3; | |
138 | ||
139 | output[0] = input[0] >> 2; | |
140 | output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); | |
141 | output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); | |
142 | output[3] = input[2] & 0x3f; | |
143 | Assert(output[0] < 64); | |
144 | Assert(output[1] < 64); | |
145 | Assert(output[2] < 64); | |
146 | Assert(output[3] < 64); | |
147 | ||
148 | if (datalength + 4 > targsize) | |
149 | return (-1); | |
150 | target[datalength++] = Base64[output[0]]; | |
151 | target[datalength++] = Base64[output[1]]; | |
152 | target[datalength++] = Base64[output[2]]; | |
153 | target[datalength++] = Base64[output[3]]; | |
154 | } | |
6f9d8e68 | 155 | |
df21c858 UD |
156 | /* Now we worry about padding. */ |
157 | if (0 != srclength) { | |
158 | /* Get what's left. */ | |
159 | input[0] = input[1] = input[2] = '\0'; | |
160 | for (i = 0; i < srclength; i++) | |
161 | input[i] = *src++; | |
6f9d8e68 | 162 | |
df21c858 UD |
163 | output[0] = input[0] >> 2; |
164 | output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); | |
165 | output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); | |
166 | Assert(output[0] < 64); | |
167 | Assert(output[1] < 64); | |
168 | Assert(output[2] < 64); | |
169 | ||
170 | if (datalength + 4 > targsize) | |
171 | return (-1); | |
172 | target[datalength++] = Base64[output[0]]; | |
173 | target[datalength++] = Base64[output[1]]; | |
174 | if (srclength == 1) | |
175 | target[datalength++] = Pad64; | |
176 | else | |
177 | target[datalength++] = Base64[output[2]]; | |
178 | target[datalength++] = Pad64; | |
179 | } | |
180 | if (datalength >= targsize) | |
181 | return (-1); | |
182 | target[datalength] = '\0'; /* Returned value doesn't count \0. */ | |
183 | return (datalength); | |
184 | } | |
6f9d8e68 | 185 | libresolv_hidden_def (b64_ntop) |
df21c858 UD |
186 | |
187 | /* skips all whitespace anywhere. | |
188 | converts characters, four at a time, starting at (or after) | |
189 | src from base - 64 numbers into three 8 bit bytes in the target area. | |
190 | it returns the number of data bytes stored at the target, or -1 on error. | |
191 | */ | |
192 | ||
845dcb57 | 193 | int |
9d46370c | 194 | b64_pton (char const *src, u_char *target, size_t targsize) |
df21c858 | 195 | { |
e685e07d | 196 | int tarindex, state, ch; |
df21c858 UD |
197 | char *pos; |
198 | ||
199 | state = 0; | |
200 | tarindex = 0; | |
201 | ||
202 | while ((ch = *src++) != '\0') { | |
203 | if (isspace(ch)) /* Skip whitespace anywhere. */ | |
204 | continue; | |
205 | ||
206 | if (ch == Pad64) | |
207 | break; | |
208 | ||
209 | pos = strchr(Base64, ch); | |
210 | if (pos == 0) /* A non-base64 character. */ | |
211 | return (-1); | |
212 | ||
213 | switch (state) { | |
214 | case 0: | |
215 | if (target) { | |
e685e07d | 216 | if ((size_t)tarindex >= targsize) |
df21c858 UD |
217 | return (-1); |
218 | target[tarindex] = (pos - Base64) << 2; | |
219 | } | |
220 | state = 1; | |
221 | break; | |
222 | case 1: | |
223 | if (target) { | |
e685e07d | 224 | if ((size_t)tarindex + 1 >= targsize) |
df21c858 UD |
225 | return (-1); |
226 | target[tarindex] |= (pos - Base64) >> 4; | |
227 | target[tarindex+1] = ((pos - Base64) & 0x0f) | |
228 | << 4 ; | |
229 | } | |
230 | tarindex++; | |
231 | state = 2; | |
232 | break; | |
233 | case 2: | |
234 | if (target) { | |
e685e07d | 235 | if ((size_t)tarindex + 1 >= targsize) |
df21c858 UD |
236 | return (-1); |
237 | target[tarindex] |= (pos - Base64) >> 2; | |
238 | target[tarindex+1] = ((pos - Base64) & 0x03) | |
239 | << 6; | |
240 | } | |
241 | tarindex++; | |
242 | state = 3; | |
243 | break; | |
244 | case 3: | |
245 | if (target) { | |
e685e07d | 246 | if ((size_t)tarindex >= targsize) |
df21c858 UD |
247 | return (-1); |
248 | target[tarindex] |= (pos - Base64); | |
249 | } | |
250 | tarindex++; | |
251 | state = 0; | |
252 | break; | |
253 | default: | |
254 | abort(); | |
255 | } | |
256 | } | |
257 | ||
258 | /* | |
259 | * We are done decoding Base-64 chars. Let's see if we ended | |
260 | * on a byte boundary, and/or with erroneous trailing characters. | |
261 | */ | |
262 | ||
263 | if (ch == Pad64) { /* We got a pad char. */ | |
264 | ch = *src++; /* Skip it, get next. */ | |
265 | switch (state) { | |
266 | case 0: /* Invalid = in first position */ | |
267 | case 1: /* Invalid = in second position */ | |
268 | return (-1); | |
269 | ||
270 | case 2: /* Valid, means one byte of info */ | |
271 | /* Skip any number of spaces. */ | |
e685e07d | 272 | for ((void)NULL; ch != '\0'; ch = *src++) |
df21c858 UD |
273 | if (!isspace(ch)) |
274 | break; | |
275 | /* Make sure there is another trailing = sign. */ | |
276 | if (ch != Pad64) | |
277 | return (-1); | |
278 | ch = *src++; /* Skip the = */ | |
279 | /* Fall through to "single trailing =" case. */ | |
280 | /* FALLTHROUGH */ | |
281 | ||
282 | case 3: /* Valid, means two bytes of info */ | |
283 | /* | |
284 | * We know this char is an =. Is there anything but | |
285 | * whitespace after it? | |
286 | */ | |
e685e07d | 287 | for ((void)NULL; ch != '\0'; ch = *src++) |
df21c858 UD |
288 | if (!isspace(ch)) |
289 | return (-1); | |
290 | ||
291 | /* | |
292 | * Now make sure for cases 2 and 3 that the "extra" | |
293 | * bits that slopped past the last full byte were | |
294 | * zeros. If we don't check them, they become a | |
295 | * subliminal channel. | |
296 | */ | |
297 | if (target && target[tarindex] != 0) | |
298 | return (-1); | |
299 | } | |
300 | } else { | |
301 | /* | |
302 | * We ended by seeing the end of the string. Make sure we | |
303 | * have no partial bytes lying around. | |
304 | */ | |
305 | if (state != 0) | |
306 | return (-1); | |
307 | } | |
308 | ||
309 | return (tarindex); | |
310 | } |