2 * Copyright (c) 1996, 1998 by Internet Software Consortium.
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.
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
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
25 * not be used in connection with the marketing of any product incorporating
26 * the Software or modifications thereof, without specific, written prior
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.
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.
42 #include <ldns/config.h>
44 #include <sys/types.h>
45 #include <sys/param.h>
46 #ifdef HAVE_SYS_SOCKET_H
47 #include <sys/socket.h>
50 #ifdef HAVE_NETINET_IN_H
51 #include <netinet/in.h>
53 #ifdef HAVE_ARPA_INET_H
54 #include <arpa/inet.h>
62 #define Assert(Cond) if (!(Cond)) abort()
64 static const char Base64[] =
65 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
66 static const char Pad64 = '=';
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
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.)
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.
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
87 Table 1: The Base64 Alphabet
89 Value Encoding Value Encoding Value Encoding Value Encoding
104 14 O 31 f 48 w (pad) =
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.
115 Since all base64 input is an integral number of octets, only the
116 -------------------------------------------------
117 following cases can arise:
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
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.
131 /* skips all whitespace anywhere.
132 converts characters, four at a time, starting at (or after)
133 src from base - 64 numbers into three 8 bit bytes in the target area.
134 it returns the number of data bytes stored at the target, or -1 on error.
138 ldns_b64_pton(char const *src, uint8_t *target, size_t targsize)
140 int tarindex, state, ch;
146 if (strlen(src) == 0) {
150 while ((ch = *src++) != '\0') {
151 if (isspace((unsigned char)ch)) /* Skip whitespace anywhere. */
157 pos = strchr(Base64, ch);
159 /* A non-base64 character. */
166 if ((size_t)tarindex >= targsize)
168 target[tarindex] = (pos - Base64) << 2;
174 if ((size_t)tarindex + 1 >= targsize)
176 target[tarindex] |= (pos - Base64) >> 4;
177 target[tarindex+1] = ((pos - Base64) & 0x0f)
185 if ((size_t)tarindex + 1 >= targsize)
187 target[tarindex] |= (pos - Base64) >> 2;
188 target[tarindex+1] = ((pos - Base64) & 0x03)
196 if ((size_t)tarindex >= targsize)
198 target[tarindex] |= (pos - Base64);
209 * We are done decoding Base-64 chars. Let's see if we ended
210 * on a byte boundary, and/or with erroneous trailing characters.
213 if (ch == Pad64) { /* We got a pad char. */
214 ch = *src++; /* Skip it, get next. */
216 case 0: /* Invalid = in first position */
217 case 1: /* Invalid = in second position */
220 case 2: /* Valid, means one byte of info */
221 /* Skip any number of spaces. */
222 for ((void)NULL; ch != '\0'; ch = *src++)
223 if (!isspace((unsigned char)ch))
225 /* Make sure there is another trailing = sign. */
228 ch = *src++; /* Skip the = */
229 /* Fall through to "single trailing =" case. */
232 case 3: /* Valid, means two bytes of info */
234 * We know this char is an =. Is there anything but
235 * whitespace after it?
237 for ((void)NULL; ch != '\0'; ch = *src++)
238 if (!isspace((unsigned char)ch))
242 * Now make sure for cases 2 and 3 that the "extra"
243 * bits that slopped past the last full byte were
244 * zeros. If we don't check them, they become a
245 * subliminal channel.
247 if (target && target[tarindex] != 0)
252 * We ended by seeing the end of the string. Make sure we
253 * have no partial bytes lying around.