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
43/*
44 * Portions copyright (c) 1999, 2000
45 * Intel Corporation.
46 * All rights reserved.
47 *
48 * Redistribution and use in source and binary forms, with or without
49 * modification, are permitted provided that the following conditions
50 * are met:
51 *
52 * 1. Redistributions of source code must retain the above copyright
53 *    notice, this list of conditions and the following disclaimer.
54 *
55 * 2. Redistributions in binary form must reproduce the above copyright
56 *    notice, this list of conditions and the following disclaimer in the
57 *    documentation and/or other materials provided with the distribution.
58 *
59 * 3. All advertising materials mentioning features or use of this software
60 *    must display the following acknowledgement:
61 *
62 *    This product includes software developed by Intel Corporation and
63 *    its contributors.
64 *
65 * 4. Neither the name of Intel Corporation or its contributors may be
66 *    used to endorse or promote products derived from this software
67 *    without specific prior written permission.
68 *
69 * THIS SOFTWARE IS PROVIDED BY INTEL CORPORATION AND CONTRIBUTORS ``AS IS''
70 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
71 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
72 * ARE DISCLAIMED.  IN NO EVENT SHALL INTEL CORPORATION OR CONTRIBUTORS BE
73 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
74 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
75 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
76 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
77 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
78 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
79 * THE POSSIBILITY OF SUCH DAMAGE.
80 *
81  base64.c,v 1.1.1.1 2003/11/19 01:51:25 kyu3 Exp
82 */
83
84#include <sys/types.h>
85#include <sys/param.h>
86#include <sys/socket.h>
87
88#include <netinet/in.h>
89#include <arpa/inet.h>
90#include <arpa/nameser.h>
91
92#include <ctype.h>
93#include <resolv.h>
94#include <stdio.h>
95#include <stdlib.h>
96#include <string.h>
97
98#define Assert(Cond) if (!(Cond)) abort()
99
100static const char Base64[] =
101  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
102static const char Pad64 = '=';
103
104/* (From RFC1521 and draft-ietf-dnssec-secext-03.txt)
105   The following encoding technique is taken from RFC 1521 by Borenstein
106   and Freed.  It is reproduced here in a slightly edited form for
107   convenience.
108
109   A 65-character subset of US-ASCII is used, enabling 6 bits to be
110   represented per printable character. (The extra 65th character, "=",
111   is used to signify a special processing function.)
112
113   The encoding process represents 24-bit groups of input bits as output
114   strings of 4 encoded characters. Proceeding from left to right, a
115   24-bit input group is formed by concatenating 3 8-bit input groups.
116   These 24 bits are then treated as 4 concatenated 6-bit groups, each
117   of which is translated into a single digit in the base64 alphabet.
118
119   Each 6-bit group is used as an index into an array of 64 printable
120   characters. The character referenced by the index is placed in the
121   output string.
122
123                         Table 1: The Base64 Alphabet
124
125      Value Encoding  Value Encoding  Value Encoding  Value Encoding
126          0 A            17 R            34 i            51 z
127          1 B            18 S            35 j            52 0
128          2 C            19 T            36 k            53 1
129          3 D            20 U            37 l            54 2
130          4 E            21 V            38 m            55 3
131          5 F            22 W            39 n            56 4
132          6 G            23 X            40 o            57 5
133          7 H            24 Y            41 p            58 6
134          8 I            25 Z            42 q            59 7
135          9 J            26 a            43 r            60 8
136         10 K            27 b            44 s            61 9
137         11 L            28 c            45 t            62 +
138         12 M            29 d            46 u            63 /
139         13 N            30 e            47 v
140         14 O            31 f            48 w         (pad) =
141         15 P            32 g            49 x
142         16 Q            33 h            50 y
143
144   Special processing is performed if fewer than 24 bits are available
145   at the end of the data being encoded.  A full encoding quantum is
146   always completed at the end of a quantity.  When fewer than 24 input
147   bits are available in an input group, zero bits are added (on the
148   right) to form an integral number of 6-bit groups.  Padding at the
149   end of the data is performed using the '=' character.
150
151   Since all base64 input is an integral number of octets, only the
152         -------------------------------------------------
153   following cases can arise:
154
155       (1) the final quantum of encoding input is an integral
156           multiple of 24 bits; here, the final unit of encoded
157     output will be an integral multiple of 4 characters
158     with no "=" padding,
159       (2) the final quantum of encoding input is exactly 8 bits;
160           here, the final unit of encoded output will be two
161     characters followed by two "=" padding characters, or
162       (3) the final quantum of encoding input is exactly 16 bits;
163           here, the final unit of encoded output will be three
164     characters followed by one "=" padding character.
165   */
166
167int
168b64_ntop(u_char const *src, size_t srclength, char *target, size_t targsize) {
169  size_t datalength = 0;
170  u_char input[3];
171  u_char output[4];
172  size_t i;
173
174  input[0] = input[1] = input[2] = '\0';
175  while (2 < srclength) {
176    input[0] = *src++;
177    input[1] = *src++;
178    input[2] = *src++;
179    srclength -= 3;
180
181    output[0] = input[0] >> 2;
182    output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
183    output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
184    output[3] = input[2] & 0x3f;
185    Assert(output[0] < 64);
186    Assert(output[1] < 64);
187    Assert(output[2] < 64);
188    Assert(output[3] < 64);
189
190    if (datalength + 4 > targsize)
191      return (-1);
192    target[datalength++] = Base64[output[0]];
193    target[datalength++] = Base64[output[1]];
194    target[datalength++] = Base64[output[2]];
195    target[datalength++] = Base64[output[3]];
196  }
197
198  /* Now we worry about padding. */
199  if (0 != srclength) {
200    /* Get what's left. */
201    input[0] = input[1] = input[2] = '\0';
202    for (i = 0; i < srclength; i++)
203      input[i] = *src++;
204
205    output[0] = input[0] >> 2;
206    output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
207    output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
208    Assert(output[0] < 64);
209    Assert(output[1] < 64);
210    Assert(output[2] < 64);
211
212    if (datalength + 4 > targsize)
213      return (-1);
214    target[datalength++] = Base64[output[0]];
215    target[datalength++] = Base64[output[1]];
216    if (srclength == 1)
217      target[datalength++] = Pad64;
218    else
219      target[datalength++] = Base64[output[2]];
220    target[datalength++] = Pad64;
221  }
222  if (datalength >= targsize)
223    return (-1);
224  target[datalength] = '\0';  /* Returned value doesn't count \0. */
225  return ((int)datalength);
226}
227
228/* skips all whitespace anywhere.
229   converts characters, four at a time, starting at (or after)
230   src from base - 64 numbers into three 8 bit bytes in the target area.
231   it returns the number of data bytes stored at the target, or -1 on error.
232 */
233
234int
235b64_pton(
236  char const *src,
237  u_char *target,
238  size_t targsize
239  )
240{
241  int tarindex, state, ch;
242  char *pos;
243
244  state = 0;
245  tarindex = 0;
246
247  while ((ch = *src++) != '\0') {
248    if (isspace(ch))  /* Skip whitespace anywhere. */
249      continue;
250
251    if (ch == Pad64)
252      break;
253
254    pos = strchr(Base64, ch);
255    if (pos == 0)     /* A non-base64 character. */
256      return (-1);
257
258    switch (state) {
259    case 0:
260      if (target) {
261        if ((size_t)tarindex >= targsize)
262          return (-1);
263        target[tarindex] = (u_char)((pos - Base64) << 2);
264      }
265      state = 1;
266      break;
267    case 1:
268      if (target) {
269        if ((size_t)tarindex + 1 >= targsize)
270          return (-1);
271        target[tarindex]   |= (u_char)((pos - Base64) >> 4);
272        target[tarindex+1]  = (u_char)(((pos - Base64) & 0x0f)
273              << 4) ;
274      }
275      tarindex++;
276      state = 2;
277      break;
278    case 2:
279      if (target) {
280        if ((size_t)tarindex + 1 >= targsize)
281          return (-1);
282        target[tarindex]   |= (u_char)((pos - Base64) >> 2);
283        target[tarindex+1]  = (u_char)(((pos - Base64) & 0x03)
284              << 6);
285      }
286      tarindex++;
287      state = 3;
288      break;
289    case 3:
290      if (target) {
291        if ((size_t)tarindex >= targsize)
292          return (-1);
293        target[tarindex] |= (u_char)(pos - Base64);
294      }
295      tarindex++;
296      state = 0;
297      break;
298    default:
299      abort();
300    }
301  }
302
303  /*
304   * We are done decoding Base-64 chars.  Let's see if we ended
305   * on a byte boundary, and/or with erroneous trailing characters.
306   */
307
308  if (ch == Pad64) {    /* We got a pad char. */
309    ch = *src++;    /* Skip it, get next. */
310    switch (state) {
311    case 0:   /* Invalid = in first position */
312    case 1:   /* Invalid = in second position */
313      return (-1);
314
315    case 2:   /* Valid, means one byte of info */
316      /* Skip any number of spaces. */
317      for ((void)NULL; ch != '\0'; ch = *src++)
318        if (!isspace(ch))
319          break;
320      /* Make sure there is another trailing = sign. */
321      if (ch != Pad64)
322        return (-1);
323      ch = *src++;    /* Skip the = */
324      /* Fall through to "single trailing =" case. */
325      /* FALLTHROUGH */
326
327    case 3:   /* Valid, means two bytes of info */
328      /*
329       * We know this char is an =.  Is there anything but
330       * whitespace after it?
331       */
332      for ((void)NULL; ch != '\0'; ch = *src++)
333        if (!isspace(ch))
334          return (-1);
335
336      /*
337       * Now make sure for cases 2 and 3 that the "extra"
338       * bits that slopped past the last full byte were
339       * zeros.  If we don't check them, they become a
340       * subliminal channel.
341       */
342      if (target && target[tarindex] != 0)
343        return (-1);
344    }
345  } else {
346    /*
347     * We ended by seeing the end of the string.  Make sure we
348     * have no partial bytes lying around.
349     */
350    if (state != 0)
351      return (-1);
352  }
353
354  return (tarindex);
355}
356