2 * Copyright (c) 1996, 1998 by Internet Software Consortium.
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14 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
19 * Portions Copyright (c) 1995 by International Business Machines, Inc.
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
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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
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42 #include <ldns/config.h>
45 #include <sys/types.h>
46 #include <sys/param.h>
47 #ifdef HAVE_SYS_SOCKET_H
48 #include <sys/socket.h>
51 #ifdef HAVE_NETINET_IN_H
52 #include <netinet/in.h>
54 #ifdef HAVE_ARPA_INET_H
55 #include <arpa/inet.h>
63 #include <ldns/util.h>
65 /* "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";*/
66 static const char Base32[] =
67 "abcdefghijklmnopqrstuvwxyz234567";
68 /* "0123456789ABCDEFGHIJKLMNOPQRSTUV";*/
69 static const char Base32_extended_hex[] =
70 "0123456789abcdefghijklmnopqrstuv";
71 static const char Pad32 = '=';
73 /* (From RFC1521 and draft-ietf-dnssec-secext-03.txt)
76 The Base 32 encoding is designed to represent arbitrary sequences of
77 octets in a form that needs to be case insensitive but need not be
80 A 33-character subset of US-ASCII is used, enabling 5 bits to be
81 represented per printable character. (The extra 33rd character, "=",
82 is used to signify a special processing function.)
84 The encoding process represents 40-bit groups of input bits as output
85 strings of 8 encoded characters. Proceeding from left to right, a
86 40-bit input group is formed by concatenating 5 8bit input groups.
87 These 40 bits are then treated as 8 concatenated 5-bit groups, each
88 of which is translated into a single digit in the base 32 alphabet.
89 When encoding a bit stream via the base 32 encoding, the bit stream
90 must be presumed to be ordered with the most-significant-bit first.
91 That is, the first bit in the stream will be the high-order bit in
92 the first 8bit byte, and the eighth bit will be the low-order bit in
93 the first 8bit byte, and so on.
95 Each 5-bit group is used as an index into an array of 32 printable
96 characters. The character referenced by the index is placed in the
97 output string. These characters, identified in Table 3, below, are
98 selected from US-ASCII digits and uppercase letters.
100 Table 3: The Base 32 Alphabet
102 Value Encoding Value Encoding Value Encoding Value Encoding
109 6 G 15 P 24 Y (pad) =
114 Special processing is performed if fewer than 40 bits are available
115 at the end of the data being encoded. A full encoding quantum is
116 always completed at the end of a body. When fewer than 40 input bits
117 are available in an input group, zero bits are added (on the right)
118 to form an integral number of 5-bit groups. Padding at the end of
119 the data is performed using the "=" character. Since all base 32
120 input is an integral number of octets, only the following cases can
123 (1) the final quantum of encoding input is an integral multiple of 40
124 bits; here, the final unit of encoded output will be an integral
125 multiple of 8 characters with no "=" padding,
127 (2) the final quantum of encoding input is exactly 8 bits; here, the
128 final unit of encoded output will be two characters followed by six
129 "=" padding characters,
131 (3) the final quantum of encoding input is exactly 16 bits; here, the
132 final unit of encoded output will be four characters followed by four
133 "=" padding characters,
135 (4) the final quantum of encoding input is exactly 24 bits; here, the
136 final unit of encoded output will be five characters followed by
137 three "=" padding characters, or
139 (5) the final quantum of encoding input is exactly 32 bits; here, the
140 final unit of encoded output will be seven characters followed by one
141 "=" padding character.
144 6. Base 32 Encoding with Extended Hex Alphabet
146 The following description of base 32 is due to [7]. This encoding
147 should not be regarded as the same as the "base32" encoding, and
148 should not be referred to as only "base32".
150 One property with this alphabet, that the base32 and base32 alphabet
151 lack, is that encoded data maintain its sort order when the encoded
152 data is compared bit-wise.
154 This encoding is identical to the previous one, except for the
155 alphabet. The new alphabet is found in table 4.
157 Table 4: The "Extended Hex" Base 32 Alphabet
159 Value Encoding Value Encoding Value Encoding Value Encoding
166 6 6 15 F 24 O (pad) =
174 /* skips all whitespace anywhere.
175 converts characters, four at a time, starting at (or after)
176 src from base - 32 numbers into three 8 bit bytes in the target area.
177 it returns the number of data bytes stored at the target, or -1 on error.
181 ldns_b32_pton_ar(char const *src, size_t hashed_owner_str_len, uint8_t *target, size_t targsize, const char B32_ar[])
183 int tarindex, state, ch;
190 while ((ch = *src++) != '\0' && (i == 0 || i < (int) hashed_owner_str_len)) {
193 if (isspace((unsigned char)ch)) /* Skip whitespace anywhere. */
199 pos = strchr(B32_ar, ch);
201 /* A non-base32 character. */
208 if ((size_t)tarindex >= targsize) {
211 target[tarindex] = (pos - B32_ar) << 3;
217 if ((size_t)tarindex + 1 >= targsize) {
220 target[tarindex] |= (pos - B32_ar) >> 2;
221 target[tarindex+1] = ((pos - B32_ar) & 0x03)
229 if ((size_t)tarindex + 1 >= targsize) {
232 target[tarindex] |= (pos - B32_ar) << 1;
239 if ((size_t)tarindex + 1 >= targsize) {
242 target[tarindex] |= (pos - B32_ar) >> 4;
243 target[tarindex+1] = ((pos - B32_ar) & 0x0f) << 4 ;
250 if ((size_t)tarindex + 1 >= targsize) {
253 target[tarindex] |= (pos - B32_ar) >> 1;
254 target[tarindex+1] = ((pos - B32_ar) & 0x01)
262 if ((size_t)tarindex + 1 >= targsize) {
265 target[tarindex] |= (pos - B32_ar) << 2;
271 if ((size_t)tarindex + 1 >= targsize) {
274 target[tarindex] |= (pos - B32_ar) >> 3;
275 target[tarindex+1] = ((pos - B32_ar) & 0x07)
283 if ((size_t)tarindex + 1 >= targsize) {
286 target[tarindex] |= (pos - B32_ar);
297 * We are done decoding Base-32 chars. Let's see if we ended
298 * on a byte boundary, and/or with erroneous trailing characters.
301 if (ch == Pad32) { /* We got a pad char. */
302 ch = *src++; /* Skip it, get next. */
304 case 0: /* Invalid = in first position */
305 case 1: /* Invalid = in second position */
308 case 2: /* Valid, means one byte of info */
310 /* Skip any number of spaces. */
311 for ((void)NULL; ch != '\0'; ch = *src++)
312 if (!isspace((unsigned char)ch))
314 /* Make sure there is another trailing = sign. */
318 ch = *src++; /* Skip the = */
319 /* Fall through to "single trailing =" case. */
322 case 4: /* Valid, means two bytes of info */
326 * We know this char is an =. Is there anything but
327 * whitespace after it?
329 for ((void)NULL; ch != '\0'; ch = *src++)
330 if (!(isspace((unsigned char)ch) || ch == '=')) {
334 case 7: /* Valid, means three bytes of info */
336 * We know this char is an =. Is there anything but
337 * whitespace after it?
339 for ((void)NULL; ch != '\0'; ch = *src++)
340 if (!isspace((unsigned char)ch)) {
345 * Now make sure for cases 2 and 3 that the "extra"
346 * bits that slopped past the last full byte were
347 * zeros. If we don't check them, they become a
348 * subliminal channel.
350 if (target && target[tarindex] != 0) {
356 * We ended by seeing the end of the string. Make sure we
357 * have no partial bytes lying around.
367 ldns_b32_pton(char const *src, size_t hashed_owner_str_len, uint8_t *target, size_t targsize)
369 return ldns_b32_pton_ar(src, hashed_owner_str_len, target, targsize, Base32);
372 /* deprecated, here for backwards compatibility */
374 b32_pton(char const *src, size_t hashed_owner_str_len, uint8_t *target, size_t targsize)
376 return ldns_b32_pton_ar(src, hashed_owner_str_len, target, targsize, Base32);
380 ldns_b32_pton_extended_hex(char const *src, size_t hashed_owner_str_len, uint8_t *target, size_t targsize)
382 return ldns_b32_pton_ar(src, hashed_owner_str_len, target, targsize, Base32_extended_hex);
385 /* deprecated, here for backwards compatibility */
387 b32_pton_extended_hex(char const *src, size_t hashed_owner_str_len, uint8_t *target, size_t targsize)
389 return ldns_b32_pton_ar(src, hashed_owner_str_len, target, targsize, Base32_extended_hex);
392 #endif /* !HAVE_B32_PTON */