b32_pton.c

Revision 32, 11.8 kB (checked in by kjaleel, 5 years ago)
unzipped the DotTel?.zip and moved it into trunk

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1	/*
2	* Copyright (c) 1996, 1998 by Internet Software Consortium.
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	#include "ldns/config.h"
43
44	#include "ldns.h"
45
46	#include <sys/types.h>
47	#include <sys/param.h>
48	#ifdef HAVE_SYS_SOCKET_H
49	#include <sys/socket.h>
50	#endif
51
52	#ifdef HAVE_NETINET_IN_H
53	#include <netinet/in.h>
54	#endif
55	#ifdef HAVE_ARPA_INET_H
56	#include <arpa/inet.h>
57	#endif
58
59	#include <ctype.h>
60	#include <stdio.h>
61	#include <stdlib.h>
62	#include <string.h>
63
64	/* "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";*/
65	static const char Base32[] =
66	"abcdefghijklmnopqrstuvwxyz234567";
67	/* "0123456789ABCDEFGHIJKLMNOPQRSTUV";*/
68	static const char Base32_extended_hex[] =
69	"0123456789abcdefghijklmnopqrstuv";
70	static const char Pad32 = '=';
71
72	/* (From RFC1521 and draft-ietf-dnssec-secext-03.txt)
73	5. Base 32 Encoding
74
75	The Base 32 encoding is designed to represent arbitrary sequences of
76	octets in a form that needs to be case insensitive but need not be
77	humanly readable.
78
79	A 33-character subset of US-ASCII is used, enabling 5 bits to be
80	represented per printable character. (The extra 33rd character, "=",
81	is used to signify a special processing function.)
82
83	The encoding process represents 40-bit groups of input bits as output
84	strings of 8 encoded characters. Proceeding from left to right, a
85	40-bit input group is formed by concatenating 5 8bit input groups.
86	These 40 bits are then treated as 8 concatenated 5-bit groups, each
87	of which is translated into a single digit in the base 32 alphabet.
88	When encoding a bit stream via the base 32 encoding, the bit stream
89	must be presumed to be ordered with the most-significant-bit first.
90	That is, the first bit in the stream will be the high-order bit in
91	the first 8bit byte, and the eighth bit will be the low-order bit in
92	the first 8bit byte, and so on.
93
94	Each 5-bit group is used as an index into an array of 32 printable
95	characters. The character referenced by the index is placed in the
96	output string. These characters, identified in Table 3, below, are
97	selected from US-ASCII digits and uppercase letters.
98
99	Table 3: The Base 32 Alphabet
100
101	Value Encoding Value Encoding Value Encoding Value Encoding
102	0 A 9 J 18 S 27 3
103	1 B 10 K 19 T 28 4
104	2 C 11 L 20 U 29 5
105	3 D 12 M 21 V 30 6
106	4 E 13 N 22 W 31 7
107	5 F 14 O 23 X
108	6 G 15 P 24 Y (pad) =
109	7 H 16 Q 25 Z
110	8 I 17 R 26 2
111
112
113	Special processing is performed if fewer than 40 bits are available
114	at the end of the data being encoded. A full encoding quantum is
115	always completed at the end of a body. When fewer than 40 input bits
116	are available in an input group, zero bits are added (on the right)
117	to form an integral number of 5-bit groups. Padding at the end of
118	the data is performed using the "=" character. Since all base 32
119	input is an integral number of octets, only the following cases can
120	arise:
121
122	(1) the final quantum of encoding input is an integral multiple of 40
123	bits; here, the final unit of encoded output will be an integral
124	multiple of 8 characters with no "=" padding,
125
126	(2) the final quantum of encoding input is exactly 8 bits; here, the
127	final unit of encoded output will be two characters followed by six
128	"=" padding characters,
129
130	(3) the final quantum of encoding input is exactly 16 bits; here, the
131	final unit of encoded output will be four characters followed by four
132	"=" padding characters,
133
134	(4) the final quantum of encoding input is exactly 24 bits; here, the
135	final unit of encoded output will be five characters followed by
136	three "=" padding characters, or
137
138	(5) the final quantum of encoding input is exactly 32 bits; here, the
139	final unit of encoded output will be seven characters followed by one
140	"=" padding character.
141
142
143	6. Base 32 Encoding with Extended Hex Alphabet
144
145	The following description of base 32 is due to [7]. This encoding
146	should not be regarded as the same as the "base32" encoding, and
147	should not be referred to as only "base32".
148
149	One property with this alphabet, that the base32 and base32 alphabet
150	lack, is that encoded data maintain its sort order when the encoded
151	data is compared bit-wise.
152
153	This encoding is identical to the previous one, except for the
154	alphabet. The new alphabet is found in table 4.
155
156	Table 4: The "Extended Hex" Base 32 Alphabet
157
158	Value Encoding Value Encoding Value Encoding Value Encoding
159	0 0 9 9 18 I 27 R
160	1 1 10 A 19 J 28 S
161	2 2 11 B 20 K 29 T
162	3 3 12 C 21 L 30 U
163	4 4 13 D 22 M 31 V
164	5 5 14 E 23 N
165	6 6 15 F 24 O (pad) =
166	7 7 16 G 25 P
167	8 8 17 H 26 Q
168
169
170
171
172	*/
173	/* skips all whitespace anywhere.
174	converts characters, four at a time, starting at (or after)
175	src from base - 32 numbers into three 8 bit bytes in the target area.
176	it returns the number of data bytes stored at the target, or -1 on error.
177	*/
178
179	int
180	b32_pton_ar(char const src, size_t hashed_owner_str_len, uint8_t target, size_t targsize, const char B32_ar[])
181	{
182	int tarindex, state, ch;
183	char *pos;
184	int i = 0;
185
186	state = 0;
187	tarindex = 0;
188
189	while ((ch = *src++) != '\0' && (i == 0 \|\| i < (int) hashed_owner_str_len)) {
190	i++;
191	ch = tolower(ch);
192	if (isspace((unsigned char)ch)) /* Skip whitespace anywhere. */
193	continue;
194
195	if (ch == Pad32)
196	break;
197
198	pos = strchr(B32_ar, ch);
199	if (pos == 0) {
200	/* A non-base32 character. */
201	return (-ch);
202	}
203
204	switch (state) {
205	case 0:
206	if (target) {
207	if ((size_t)tarindex >= targsize) {
208	return (-2);
209	}
210	target[tarindex] = (pos - B32_ar) << 3;
211	}
212	state = 1;
213	break;
214	case 1:
215	if (target) {
216	if ((size_t)tarindex + 1 >= targsize) {
217	return (-3);
218	}
219	target[tarindex] \|= (pos - B32_ar) >> 2;
220	target[tarindex+1] = ((pos - B32_ar) & 0x03)
221	<< 6 ;
222	}
223	tarindex++;
224	state = 2;
225	break;
226	case 2:
227	if (target) {
228	if ((size_t)tarindex + 1 >= targsize) {
229	return (-4);
230	}
231	target[tarindex] \|= (pos - B32_ar) << 1;
232	}
233	/tarindex++;/
234	state = 3;
235	break;
236	case 3:
237	if (target) {
238	if ((size_t)tarindex + 1 >= targsize) {
239	return (-5);
240	}
241	target[tarindex] \|= (pos - B32_ar) >> 4;
242	target[tarindex+1] = ((pos - B32_ar) & 0x0f) << 4 ;
243	}
244	tarindex++;
245	state = 4;
246	break;
247	case 4:
248	if (target) {
249	if ((size_t)tarindex + 1 >= targsize) {
250	return (-6);
251	}
252	target[tarindex] \|= (pos - B32_ar) >> 1;
253	target[tarindex+1] = ((pos - B32_ar) & 0x01)
254	<< 7 ;
255	}
256	tarindex++;
257	state = 5;
258	break;
259	case 5:
260	if (target) {
261	if ((size_t)tarindex + 1 >= targsize) {
262	return (-7);
263	}
264	target[tarindex] \|= (pos - B32_ar) << 2;
265	}
266	state = 6;
267	break;
268	case 6:
269	if (target) {
270	if ((size_t)tarindex + 1 >= targsize) {
271	return (-8);
272	}
273	target[tarindex] \|= (pos - B32_ar) >> 3;
274	target[tarindex+1] = ((pos - B32_ar) & 0x07)
275	<< 5 ;
276	}
277	tarindex++;
278	state = 7;
279	break;
280	case 7:
281	if (target) {
282	if ((size_t)tarindex + 1 >= targsize) {
283	return (-9);
284	}
285	target[tarindex] \|= (pos - B32_ar);
286	}
287	tarindex++;
288	state = 0;
289	break;
290	default:
291	abort();
292	}
293	}
294
295	/*
296	* We are done decoding Base-32 chars. Let's see if we ended
297	* on a byte boundary, and/or with erroneous trailing characters.
298	*/
299
300	if (ch == Pad32) { /* We got a pad char. */
301	ch = src++; / Skip it, get next. */
302	switch (state) {
303	case 0: /* Invalid = in first position */
304	case 1: /* Invalid = in second position */
305	return (-10);
306
307	case 2: /* Valid, means one byte of info */
308	case 3:
309	/* Skip any number of spaces. */
310	for ((void)NULL; ch != '\0'; ch = *src++)
311	if (!isspace((unsigned char)ch))
312	break;
313	/* Make sure there is another trailing = sign. */
314	if (ch != Pad32) {
315	return (-11);
316	}
317	ch = src++; / Skip the = */
318	/* Fall through to "single trailing =" case. */
319	/* FALLTHROUGH */
320
321	case 4: /* Valid, means two bytes of info */
322	case 5:
323	case 6:
324	/*
325	* We know this char is an =. Is there anything but
326	* whitespace after it?
327	*/
328	for ((void)NULL; ch != '\0'; ch = *src++)
329	if (!(isspace((unsigned char)ch) \|\| ch == '=')) {
330	return (-12);
331	}
332
333	case 7: /* Valid, means three bytes of info */
334	/*
335	* We know this char is an =. Is there anything but
336	* whitespace after it?
337	*/
338	for ((void)NULL; ch != '\0'; ch = *src++)
339	if (!isspace((unsigned char)ch)) {
340	return (-13);
341	}
342
343	/*
344	* Now make sure for cases 2 and 3 that the "extra"
345	* bits that slopped past the last full byte were
346	* zeros. If we don't check them, they become a
347	* subliminal channel.
348	*/
349	if (target && target[tarindex] != 0) {
350	return (-14);
351	}
352	}
353	} else {
354	/*
355	* We ended by seeing the end of the string. Make sure we
356	* have no partial bytes lying around.
357	*/
358	if (state != 0)
359	return (-15);
360	}
361
362	return (tarindex);
363	}
364
365	int
366	b32_pton(char const src, size_t hashed_owner_str_len, uint8_t target, size_t targsize)
367	{
368	return b32_pton_ar(src, hashed_owner_str_len, target, targsize, Base32);
369	}
370
371	int
372	b32_pton_extended_hex(char const src, size_t hashed_owner_str_len, uint8_t target, size_t targsize)
373	{
374	return b32_pton_ar(src, hashed_owner_str_len, target, targsize, Base32_extended_hex);
375	}

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