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.
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
46 #include <sys/types.h>
47 #include <sys/param.h>
48 #include <sys/socket.h>
50 #include <netinet/in.h>
51 #include <arpa/inet.h>
52 #include <arpa/nameser.h>
60 #define Assert(Cond) if (!(Cond)) abort()
62 static const char Base64[] =
63 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
64 static const char Pad64 = '=';
66 /* (From RFC1521 and draft-ietf-dnssec-secext-03.txt)
67 The following encoding technique is taken from RFC 1521 by Borenstein
68 and Freed. It is reproduced here in a slightly edited form for
71 A 65-character subset of US-ASCII is used, enabling 6 bits to be
72 represented per printable character. (The extra 65th character, "=",
73 is used to signify a special processing function.)
75 The encoding process represents 24-bit groups of input bits as output
76 strings of 4 encoded characters. Proceeding from left to right, a
77 24-bit input group is formed by concatenating 3 8-bit input groups.
78 These 24 bits are then treated as 4 concatenated 6-bit groups, each
79 of which is translated into a single digit in the base64 alphabet.
81 Each 6-bit group is used as an index into an array of 64 printable
82 characters. The character referenced by the index is placed in the
85 Table 1: The Base64 Alphabet
87 Value Encoding Value Encoding Value Encoding Value Encoding
102 14 O 31 f 48 w (pad) =
106 Special processing is performed if fewer than 24 bits are available
107 at the end of the data being encoded. A full encoding quantum is
108 always completed at the end of a quantity. When fewer than 24 input
109 bits are available in an input group, zero bits are added (on the
110 right) to form an integral number of 6-bit groups. Padding at the
111 end of the data is performed using the '=' character.
113 Since all base64 input is an integral number of octets, only the
114 -------------------------------------------------
115 following cases can arise:
117 (1) the final quantum of encoding input is an integral
118 multiple of 24 bits; here, the final unit of encoded
119 output will be an integral multiple of 4 characters
121 (2) the final quantum of encoding input is exactly 8 bits;
122 here, the final unit of encoded output will be two
123 characters followed by two "=" padding characters, or
124 (3) the final quantum of encoding input is exactly 16 bits;
125 here, the final unit of encoded output will be three
126 characters followed by one "=" padding character.
130 b64_ntop(u_char const *src, size_t srclength, char *target, size_t targsize) {
131 size_t datalength = 0;
136 while (2 < srclength) {
142 output[0] = input[0] >> 2;
143 output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
144 output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
145 output[3] = input[2] & 0x3f;
146 Assert(output[0] < 64);
147 Assert(output[1] < 64);
148 Assert(output[2] < 64);
149 Assert(output[3] < 64);
151 if (datalength + 4 > targsize)
153 target[datalength++] = Base64[output[0]];
154 target[datalength++] = Base64[output[1]];
155 target[datalength++] = Base64[output[2]];
156 target[datalength++] = Base64[output[3]];
159 /* Now we worry about padding. */
160 if (0 != srclength) {
161 /* Get what's left. */
162 input[0] = input[1] = input[2] = '\0';
163 for (i = 0; i < srclength; i++)
166 output[0] = input[0] >> 2;
167 output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
168 output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
169 Assert(output[0] < 64);
170 Assert(output[1] < 64);
171 Assert(output[2] < 64);
173 if (datalength + 4 > targsize)
175 target[datalength++] = Base64[output[0]];
176 target[datalength++] = Base64[output[1]];
178 target[datalength++] = Pad64;
180 target[datalength++] = Base64[output[2]];
181 target[datalength++] = Pad64;
183 if (datalength >= targsize)
185 target[datalength] = '\0'; /* Returned value doesn't count \0. */
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.
196 b64_pton(const char *src, u_char *target, size_t targsize)
198 int tarindex, state, ch;
205 while ((ch = *src++) != '\0') {
206 if (isspace((unsigned char)ch)) /* Skip whitespace anywhere. */
212 pos = strchr(Base64, ch);
213 if (pos == NULL) /* A non-base64 character. */
219 if ((size_t)tarindex >= targsize)
221 target[tarindex] = (pos - Base64) << 2;
227 if ((size_t)tarindex >= targsize)
229 target[tarindex] |= (pos - Base64) >> 4;
230 nextbyte = ((pos - Base64) & 0x0f) << 4;
231 if ((size_t)tarindex + 1 < targsize)
232 target[tarindex + 1] = nextbyte;
241 if ((size_t)tarindex >= targsize)
243 target[tarindex] |= (pos - Base64) >> 2;
244 nextbyte = ((pos - Base64) & 0x03) << 6;
245 if ((size_t)tarindex + 1 < targsize)
246 target[tarindex + 1] = nextbyte;
255 if ((size_t)tarindex >= targsize)
257 target[tarindex] |= (pos - Base64);
268 * We are done decoding Base-64 chars. Let's see if we ended
269 * on a byte boundary, and/or with erroneous trailing characters.
272 if (ch == Pad64) { /* We got a pad char. */
273 ch = *src++; /* Skip it, get next. */
275 case 0: /* Invalid = in first position */
276 case 1: /* Invalid = in second position */
279 case 2: /* Valid, means one byte of info */
280 /* Skip any number of spaces. */
281 for ((void)NULL; ch != '\0'; ch = *src++)
282 if (!isspace((unsigned char)ch))
284 /* Make sure there is another trailing = sign. */
287 ch = *src++; /* Skip the = */
288 /* Fall through to "single trailing =" case. */
291 case 3: /* Valid, means two bytes of info */
293 * We know this char is an =. Is there anything but
294 * whitespace after it?
296 for ((void)NULL; ch != '\0'; ch = *src++)
297 if (!isspace((unsigned char)ch))
301 * Now make sure for cases 2 and 3 that the "extra"
302 * bits that slopped past the last full byte were
303 * zeros. If we don't check them, they become a
304 * subliminal channel.
306 if (target && (size_t)tarindex < targsize &&
307 target[tarindex] != 0)
312 * We ended by seeing the end of the string. Make sure we
313 * have no partial bytes lying around.