Annotation of embedaddon/dhcp/dst/base64.c, revision 1.1.1.1
1.1 misho 1: /*
2: * Copyright (c) 2004,2009 by Internet Systems Consortium, Inc. ("ISC")
3: * Copyright (c) 1996-2003 by Internet Software Consortium
4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15: * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: *
17: * Internet Systems Consortium, Inc.
18: * 950 Charter Street
19: * Redwood City, CA 94063
20: * <info@isc.org>
21: * https://www.isc.org/
22: */
23:
24: /*
25: * Portions Copyright (c) 1995 by International Business Machines, Inc.
26: *
27: * International Business Machines, Inc. (hereinafter called IBM) grants
28: * permission under its copyrights to use, copy, modify, and distribute this
29: * Software with or without fee, provided that the above copyright notice and
30: * all paragraphs of this notice appear in all copies, and that the name of IBM
31: * not be used in connection with the marketing of any product incorporating
32: * the Software or modifications thereof, without specific, written prior
33: * permission.
34: *
35: * To the extent it has a right to do so, IBM grants an immunity from suit
36: * under its patents, if any, for the use, sale or manufacture of products to
37: * the extent that such products are used for performing Domain Name System
38: * dynamic updates in TCP/IP networks by means of the Software. No immunity is
39: * granted for any product per se or for any other function of any product.
40: *
41: * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES,
42: * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
43: * PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL,
44: * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING
45: * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN
46: * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES.
47: */
48:
49: #if !defined(LINT) && !defined(CODECENTER)
1.1.1.1 ! misho 50: static const char rcsid[] = "$Id: base64.c,v 1.2.786.2 2009/07/24 22:04:52 sar Exp $";
1.1 misho 51: #endif /* not lint */
52:
53: #include <sys/types.h>
54: #include <sys/param.h>
55: #include <sys/socket.h>
56:
57: #include <netinet/in.h>
58: #include <arpa/inet.h>
59:
60: #include <ctype.h>
61: #include <stdio.h>
62: #include <stdlib.h>
63: #include <string.h>
64:
65: #include <sys/socket.h>
66:
67: #include "minires/minires.h"
68: #include "arpa/nameser.h"
69:
70: #define Assert(Cond) if (!(Cond)) abort()
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
140: b64_ntop(u_char const *src, size_t srclength, char *target, size_t targsize) {
141: size_t datalength = 0;
142: u_char input[3];
143: u_char output[4];
144: size_t i;
145:
146: while (2 < srclength) {
147: input[0] = *src++;
148: input[1] = *src++;
149: input[2] = *src++;
150: srclength -= 3;
151:
152: output[0] = input[0] >> 2;
153: output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
154: output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
155: output[3] = input[2] & 0x3f;
156: Assert(output[0] < 64);
157: Assert(output[1] < 64);
158: Assert(output[2] < 64);
159: Assert(output[3] < 64);
160:
161: if (datalength + 4 > targsize)
162: return (-1);
163: target[datalength++] = Base64[output[0]];
164: target[datalength++] = Base64[output[1]];
165: target[datalength++] = Base64[output[2]];
166: target[datalength++] = Base64[output[3]];
167: }
168:
169: /* Now we worry about padding. */
170: if (0 != srclength) {
171: /* Get what's left. */
172: input[0] = input[1] = input[2] = '\0';
173: for (i = 0; i < srclength; i++)
174: input[i] = *src++;
175:
176: output[0] = input[0] >> 2;
177: output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
178: output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
179: Assert(output[0] < 64);
180: Assert(output[1] < 64);
181: Assert(output[2] < 64);
182:
183: if (datalength + 4 > targsize)
184: return (-1);
185: target[datalength++] = Base64[output[0]];
186: target[datalength++] = Base64[output[1]];
187: if (srclength == 1)
188: target[datalength++] = Pad64;
189: else
190: target[datalength++] = Base64[output[2]];
191: target[datalength++] = Pad64;
192: }
193: if (datalength >= targsize)
194: return (-1);
195: target[datalength] = '\0'; /* Returned value doesn't count \0. */
196: return (datalength);
197: }
198:
199: /* skips all whitespace anywhere.
200: converts characters, four at a time, starting at (or after)
201: src from base - 64 numbers into three 8 bit bytes in the target area.
202: it returns the number of data bytes stored at the target, or -1 on error.
203: */
204:
205: int
206: b64_pton(src, target, targsize)
207: char const *src;
208: u_char *target;
209: size_t targsize;
210: {
211: int tarindex, state, ch;
212: char *pos;
213:
214: state = 0;
215: tarindex = 0;
216:
217: while ((ch = *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 ((size_t)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 ((size_t)tarindex + 1 >= targsize)
240: return (-1);
241: target[tarindex] |= (pos - Base64) >> 4;
242: target[tarindex+1] = ((pos - Base64) & 0x0f)
243: << 4 ;
244: }
245: tarindex++;
246: state = 2;
247: break;
248: case 2:
249: if (target) {
250: if ((size_t)tarindex + 1 >= targsize)
251: return (-1);
252: target[tarindex] |= (pos - Base64) >> 2;
253: target[tarindex+1] = ((pos - Base64) & 0x03)
254: << 6;
255: }
256: tarindex++;
257: state = 3;
258: break;
259: case 3:
260: if (target) {
261: if ((size_t)tarindex >= targsize)
262: return (-1);
263: target[tarindex] |= (pos - Base64);
264: }
265: tarindex++;
266: state = 0;
267: break;
268: default:
269: abort();
270: }
271: }
272:
273: /*
274: * We are done decoding Base-64 chars. Let's see if we ended
275: * on a byte boundary, and/or with erroneous trailing characters.
276: */
277:
278: if (ch == Pad64) { /* We got a pad char. */
279: ch = *src++; /* Skip it, get next. */
280: switch (state) {
281: case 0: /* Invalid = in first position */
282: case 1: /* Invalid = in second position */
283: return (-1);
284:
285: case 2: /* Valid, means one byte of info */
286: /* Skip any number of spaces. */
287: for ((void)NULL; ch != '\0'; ch = *src++)
288: if (!isspace(ch))
289: break;
290: /* Make sure there is another trailing = sign. */
291: if (ch != Pad64)
292: return (-1);
293: ch = *src++; /* Skip the = */
294: /* Fall through to "single trailing =" case. */
295: /* FALLTHROUGH */
296:
297: case 3: /* Valid, means two bytes of info */
298: /*
299: * We know this char is an =. Is there anything but
300: * whitespace after it?
301: */
302: for ((void)NULL; ch != '\0'; ch = *src++)
303: if (!isspace(ch))
304: return (-1);
305:
306: /*
307: * Now make sure for cases 2 and 3 that the "extra"
308: * bits that slopped past the last full byte were
309: * zeros. If we don't check them, they become a
310: * subliminal channel.
311: */
312: if (target && target[tarindex] != 0)
313: return (-1);
314: }
315: } else {
316: /*
317: * We ended by seeing the end of the string. Make sure we
318: * have no partial bytes lying around.
319: */
320: if (state != 0)
321: return (-1);
322: }
323:
324: return (tarindex);
325: }
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