/src/openssh/openbsd-compat/base64.c
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1 | | /* $OpenBSD: base64.c,v 1.5 2006/10/21 09:55:03 otto Exp $ */ |
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 | | |
45 | | /* OPENBSD ORIGINAL: lib/libc/net/base64.c */ |
46 | | |
47 | | #include "includes.h" |
48 | | |
49 | | #if (!defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP)) || (!defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON)) |
50 | | |
51 | | #include <sys/types.h> |
52 | | #include <sys/socket.h> |
53 | | #include <netinet/in.h> |
54 | | #include <arpa/inet.h> |
55 | | |
56 | | #include <ctype.h> |
57 | | #include <stdio.h> |
58 | | |
59 | | #include <stdlib.h> |
60 | | #include <string.h> |
61 | | |
62 | | #include "base64.h" |
63 | | |
64 | | static const char Base64[] = |
65 | | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
66 | | static const char Pad64 = '='; |
67 | | |
68 | | /* (From RFC1521 and draft-ietf-dnssec-secext-03.txt) |
69 | | The following encoding technique is taken from RFC 1521 by Borenstein |
70 | | and Freed. It is reproduced here in a slightly edited form for |
71 | | convenience. |
72 | | |
73 | | A 65-character subset of US-ASCII is used, enabling 6 bits to be |
74 | | represented per printable character. (The extra 65th character, "=", |
75 | | is used to signify a special processing function.) |
76 | | |
77 | | The encoding process represents 24-bit groups of input bits as output |
78 | | strings of 4 encoded characters. Proceeding from left to right, a |
79 | | 24-bit input group is formed by concatenating 3 8-bit input groups. |
80 | | These 24 bits are then treated as 4 concatenated 6-bit groups, each |
81 | | of which is translated into a single digit in the base64 alphabet. |
82 | | |
83 | | Each 6-bit group is used as an index into an array of 64 printable |
84 | | characters. The character referenced by the index is placed in the |
85 | | output string. |
86 | | |
87 | | Table 1: The Base64 Alphabet |
88 | | |
89 | | Value Encoding Value Encoding Value Encoding Value Encoding |
90 | | 0 A 17 R 34 i 51 z |
91 | | 1 B 18 S 35 j 52 0 |
92 | | 2 C 19 T 36 k 53 1 |
93 | | 3 D 20 U 37 l 54 2 |
94 | | 4 E 21 V 38 m 55 3 |
95 | | 5 F 22 W 39 n 56 4 |
96 | | 6 G 23 X 40 o 57 5 |
97 | | 7 H 24 Y 41 p 58 6 |
98 | | 8 I 25 Z 42 q 59 7 |
99 | | 9 J 26 a 43 r 60 8 |
100 | | 10 K 27 b 44 s 61 9 |
101 | | 11 L 28 c 45 t 62 + |
102 | | 12 M 29 d 46 u 63 / |
103 | | 13 N 30 e 47 v |
104 | | 14 O 31 f 48 w (pad) = |
105 | | 15 P 32 g 49 x |
106 | | 16 Q 33 h 50 y |
107 | | |
108 | | Special processing is performed if fewer than 24 bits are available |
109 | | at the end of the data being encoded. A full encoding quantum is |
110 | | always completed at the end of a quantity. When fewer than 24 input |
111 | | bits are available in an input group, zero bits are added (on the |
112 | | right) to form an integral number of 6-bit groups. Padding at the |
113 | | end of the data is performed using the '=' character. |
114 | | |
115 | | Since all base64 input is an integral number of octets, only the |
116 | | ------------------------------------------------- |
117 | | following cases can arise: |
118 | | |
119 | | (1) the final quantum of encoding input is an integral |
120 | | multiple of 24 bits; here, the final unit of encoded |
121 | | output will be an integral multiple of 4 characters |
122 | | with no "=" padding, |
123 | | (2) the final quantum of encoding input is exactly 8 bits; |
124 | | here, the final unit of encoded output will be two |
125 | | characters followed by two "=" padding characters, or |
126 | | (3) the final quantum of encoding input is exactly 16 bits; |
127 | | here, the final unit of encoded output will be three |
128 | | characters followed by one "=" padding character. |
129 | | */ |
130 | | |
131 | | #if !defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP) |
132 | | int |
133 | | b64_ntop(u_char const *src, size_t srclength, char *target, size_t targsize) |
134 | 0 | { |
135 | 0 | size_t datalength = 0; |
136 | 0 | u_char input[3]; |
137 | 0 | u_char output[4]; |
138 | 0 | u_int i; |
139 | |
|
140 | 0 | while (2 < srclength) { |
141 | 0 | input[0] = *src++; |
142 | 0 | input[1] = *src++; |
143 | 0 | input[2] = *src++; |
144 | 0 | srclength -= 3; |
145 | |
|
146 | 0 | output[0] = input[0] >> 2; |
147 | 0 | output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); |
148 | 0 | output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); |
149 | 0 | output[3] = input[2] & 0x3f; |
150 | |
|
151 | 0 | if (datalength + 4 > targsize) |
152 | 0 | return (-1); |
153 | 0 | target[datalength++] = Base64[output[0]]; |
154 | 0 | target[datalength++] = Base64[output[1]]; |
155 | 0 | target[datalength++] = Base64[output[2]]; |
156 | 0 | target[datalength++] = Base64[output[3]]; |
157 | 0 | } |
158 | | |
159 | | /* Now we worry about padding. */ |
160 | 0 | if (0 != srclength) { |
161 | | /* Get what's left. */ |
162 | 0 | input[0] = input[1] = input[2] = '\0'; |
163 | 0 | for (i = 0; i < srclength; i++) |
164 | 0 | input[i] = *src++; |
165 | | |
166 | 0 | output[0] = input[0] >> 2; |
167 | 0 | output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); |
168 | 0 | output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); |
169 | |
|
170 | 0 | if (datalength + 4 > targsize) |
171 | 0 | return (-1); |
172 | 0 | target[datalength++] = Base64[output[0]]; |
173 | 0 | target[datalength++] = Base64[output[1]]; |
174 | 0 | if (srclength == 1) |
175 | 0 | target[datalength++] = Pad64; |
176 | 0 | else |
177 | 0 | target[datalength++] = Base64[output[2]]; |
178 | 0 | target[datalength++] = Pad64; |
179 | 0 | } |
180 | 0 | if (datalength >= targsize) |
181 | 0 | return (-1); |
182 | 0 | target[datalength] = '\0'; /* Returned value doesn't count \0. */ |
183 | 0 | return (datalength); |
184 | 0 | } |
185 | | #endif /* !defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP) */ |
186 | | |
187 | | #if !defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON) |
188 | | |
189 | | /* skips all whitespace anywhere. |
190 | | converts characters, four at a time, starting at (or after) |
191 | | src from base - 64 numbers into three 8 bit bytes in the target area. |
192 | | it returns the number of data bytes stored at the target, or -1 on error. |
193 | | */ |
194 | | |
195 | | int |
196 | | b64_pton(char const *src, u_char *target, size_t targsize) |
197 | 6 | { |
198 | 6 | u_int tarindex, state; |
199 | 6 | int ch; |
200 | 6 | char *pos; |
201 | | |
202 | 6 | state = 0; |
203 | 6 | tarindex = 0; |
204 | | |
205 | 3.01k | while ((ch = *src++) != '\0') { |
206 | 3.01k | if (isspace(ch)) /* Skip whitespace anywhere. */ |
207 | 0 | continue; |
208 | | |
209 | 3.01k | if (ch == Pad64) |
210 | 2 | break; |
211 | | |
212 | 3.01k | pos = strchr(Base64, ch); |
213 | 3.01k | if (pos == 0) /* A non-base64 character. */ |
214 | 0 | return (-1); |
215 | | |
216 | 3.01k | switch (state) { |
217 | 753 | case 0: |
218 | 753 | if (target) { |
219 | 753 | if (tarindex >= targsize) |
220 | 0 | return (-1); |
221 | 753 | target[tarindex] = (pos - Base64) << 2; |
222 | 753 | } |
223 | 753 | state = 1; |
224 | 753 | break; |
225 | 753 | case 1: |
226 | 753 | if (target) { |
227 | 753 | if (tarindex + 1 >= targsize) |
228 | 0 | return (-1); |
229 | 753 | target[tarindex] |= (pos - Base64) >> 4; |
230 | 753 | target[tarindex+1] = ((pos - Base64) & 0x0f) |
231 | 753 | << 4 ; |
232 | 753 | } |
233 | 753 | tarindex++; |
234 | 753 | state = 2; |
235 | 753 | break; |
236 | 753 | case 2: |
237 | 753 | if (target) { |
238 | 753 | if (tarindex + 1 >= targsize) |
239 | 0 | return (-1); |
240 | 753 | target[tarindex] |= (pos - Base64) >> 2; |
241 | 753 | target[tarindex+1] = ((pos - Base64) & 0x03) |
242 | 753 | << 6; |
243 | 753 | } |
244 | 753 | tarindex++; |
245 | 753 | state = 3; |
246 | 753 | break; |
247 | 751 | case 3: |
248 | 751 | if (target) { |
249 | 751 | if (tarindex >= targsize) |
250 | 0 | return (-1); |
251 | 751 | target[tarindex] |= (pos - Base64); |
252 | 751 | } |
253 | 751 | tarindex++; |
254 | 751 | state = 0; |
255 | 751 | break; |
256 | 3.01k | } |
257 | 3.01k | } |
258 | | |
259 | | /* |
260 | | * We are done decoding Base-64 chars. Let's see if we ended |
261 | | * on a byte boundary, and/or with erroneous trailing characters. |
262 | | */ |
263 | | |
264 | 6 | if (ch == Pad64) { /* We got a pad char. */ |
265 | 2 | ch = *src++; /* Skip it, get next. */ |
266 | 2 | switch (state) { |
267 | 0 | case 0: /* Invalid = in first position */ |
268 | 0 | case 1: /* Invalid = in second position */ |
269 | 0 | return (-1); |
270 | | |
271 | 0 | case 2: /* Valid, means one byte of info */ |
272 | | /* Skip any number of spaces. */ |
273 | 0 | for (; ch != '\0'; ch = *src++) |
274 | 0 | if (!isspace(ch)) |
275 | 0 | break; |
276 | | /* Make sure there is another trailing = sign. */ |
277 | 0 | if (ch != Pad64) |
278 | 0 | return (-1); |
279 | 0 | ch = *src++; /* Skip the = */ |
280 | | /* Fall through to "single trailing =" case. */ |
281 | | /* FALLTHROUGH */ |
282 | |
|
283 | 2 | case 3: /* Valid, means two bytes of info */ |
284 | | /* |
285 | | * We know this char is an =. Is there anything but |
286 | | * whitespace after it? |
287 | | */ |
288 | 2 | for (; ch != '\0'; ch = *src++) |
289 | 0 | if (!isspace(ch)) |
290 | 0 | return (-1); |
291 | | |
292 | | /* |
293 | | * Now make sure for cases 2 and 3 that the "extra" |
294 | | * bits that slopped past the last full byte were |
295 | | * zeros. If we don't check them, they become a |
296 | | * subliminal channel. |
297 | | */ |
298 | 2 | if (target && target[tarindex] != 0) |
299 | 0 | return (-1); |
300 | 2 | } |
301 | 4 | } else { |
302 | | /* |
303 | | * We ended by seeing the end of the string. Make sure we |
304 | | * have no partial bytes lying around. |
305 | | */ |
306 | 4 | if (state != 0) |
307 | 0 | return (-1); |
308 | 4 | } |
309 | | |
310 | 6 | return (tarindex); |
311 | 6 | } |
312 | | |
313 | | #endif /* !defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON) */ |
314 | | #endif |