/src/openssh/openbsd-compat/base64.c

Source
/*  $OpenBSD: base64.c,v 1.5 2006/10/21 09:55:03 otto Exp $ */

/*
 * Copyright (c) 1996 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

/*
 * Portions Copyright (c) 1995 by International Business Machines, Inc.
 *
 * International Business Machines, Inc. (hereinafter called IBM) grants
 * permission under its copyrights to use, copy, modify, and distribute this
 * Software with or without fee, provided that the above copyright notice and
 * all paragraphs of this notice appear in all copies, and that the name of IBM
 * not be used in connection with the marketing of any product incorporating
 * the Software or modifications thereof, without specific, written prior
 * permission.
 *
 * To the extent it has a right to do so, IBM grants an immunity from suit
 * under its patents, if any, for the use, sale or manufacture of products to
 * the extent that such products are used for performing Domain Name System
 * dynamic updates in TCP/IP networks by means of the Software.  No immunity is
 * granted for any product per se or for any other function of any product.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE.  IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL,
 * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN
 * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES.
 */

/* OPENBSD ORIGINAL: lib/libc/net/base64.c */

#include "includes.h"

#if (!defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP)) || (!defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON))

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <ctype.h>
#include <stdio.h>

#include <stdlib.h>
#include <string.h>

#include "base64.h"

static const char Base64[] =
  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static const char Pad64 = '=';

/* (From RFC1521 and draft-ietf-dnssec-secext-03.txt)
   The following encoding technique is taken from RFC 1521 by Borenstein
   and Freed.  It is reproduced here in a slightly edited form for
   convenience.

   A 65-character subset of US-ASCII is used, enabling 6 bits to be
   represented per printable character. (The extra 65th character, "=",
   is used to signify a special processing function.)

   The encoding process represents 24-bit groups of input bits as output
   strings of 4 encoded characters. Proceeding from left to right, a
   24-bit input group is formed by concatenating 3 8-bit input groups.
   These 24 bits are then treated as 4 concatenated 6-bit groups, each
   of which is translated into a single digit in the base64 alphabet.

   Each 6-bit group is used as an index into an array of 64 printable
   characters. The character referenced by the index is placed in the
   output string.

                         Table 1: The Base64 Alphabet

      Value Encoding  Value Encoding  Value Encoding  Value Encoding
          0 A            17 R            34 i            51 z
          1 B            18 S            35 j            52 0
          2 C            19 T            36 k            53 1
          3 D            20 U            37 l            54 2
          4 E            21 V            38 m            55 3
          5 F            22 W            39 n            56 4
          6 G            23 X            40 o            57 5
          7 H            24 Y            41 p            58 6
          8 I            25 Z            42 q            59 7
          9 J            26 a            43 r            60 8
         10 K            27 b            44 s            61 9
         11 L            28 c            45 t            62 +
         12 M            29 d            46 u            63 /
         13 N            30 e            47 v
         14 O            31 f            48 w         (pad) =
         15 P            32 g            49 x
         16 Q            33 h            50 y

   Special processing is performed if fewer than 24 bits are available
   at the end of the data being encoded.  A full encoding quantum is
   always completed at the end of a quantity.  When fewer than 24 input
   bits are available in an input group, zero bits are added (on the
   right) to form an integral number of 6-bit groups.  Padding at the
   end of the data is performed using the '=' character.

   Since all base64 input is an integral number of octets, only the
         -------------------------------------------------                       
   following cases can arise:
   
       (1) the final quantum of encoding input is an integral
           multiple of 24 bits; here, the final unit of encoded
     output will be an integral multiple of 4 characters
     with no "=" padding,
       (2) the final quantum of encoding input is exactly 8 bits;
           here, the final unit of encoded output will be two
     characters followed by two "=" padding characters, or
       (3) the final quantum of encoding input is exactly 16 bits;
           here, the final unit of encoded output will be three
     characters followed by one "=" padding character.
   */

#if !defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP) 
int
b64_ntop(u_char const *src, size_t srclength, char *target, size_t targsize)
{
  size_t datalength = 0;
  u_char input[3];
  u_char output[4];
  u_int i;

  while (2 < srclength) {
    input[0] = *src++;
    input[1] = *src++;
    input[2] = *src++;
    srclength -= 3;

    output[0] = input[0] >> 2;
    output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
    output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
    output[3] = input[2] & 0x3f;

    if (datalength + 4 > targsize)
      return (-1);
    target[datalength++] = Base64[output[0]];
    target[datalength++] = Base64[output[1]];
    target[datalength++] = Base64[output[2]];
    target[datalength++] = Base64[output[3]];
  }
    
  /* Now we worry about padding. */
  if (0 != srclength) {
    /* Get what's left. */
    input[0] = input[1] = input[2] = '\0';
    for (i = 0; i < srclength; i++)
      input[i] = *src++;
  
    output[0] = input[0] >> 2;
    output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
    output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);

    if (datalength + 4 > targsize)
      return (-1);
    target[datalength++] = Base64[output[0]];
    target[datalength++] = Base64[output[1]];
    if (srclength == 1)
      target[datalength++] = Pad64;
    else
      target[datalength++] = Base64[output[2]];
    target[datalength++] = Pad64;
  }
  if (datalength >= targsize)
    return (-1);
  target[datalength] = '\0';  /* Returned value doesn't count \0. */
  return (datalength);
}
#endif /* !defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP) */

#if !defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON)

/* skips all whitespace anywhere.
   converts characters, four at a time, starting at (or after)
   src from base - 64 numbers into three 8 bit bytes in the target area.
   it returns the number of data bytes stored at the target, or -1 on error.
 */

int
b64_pton(char const *src, u_char *target, size_t targsize)
{
  u_int tarindex, state;
  int ch;
  char *pos;

  state = 0;
  tarindex = 0;

  while ((ch = *src++) != '\0') {
    if (isspace(ch))  /* Skip whitespace anywhere. */
      continue;

    if (ch == Pad64)
      break;

    pos = strchr(Base64, ch);
    if (pos == 0)    /* A non-base64 character. */
      return (-1);

    switch (state) {
    case 0:
      if (target) {
        if (tarindex >= targsize)
          return (-1);
        target[tarindex] = (pos - Base64) << 2;
      }
      state = 1;
      break;
    case 1:
      if (target) {
        if (tarindex + 1 >= targsize)
          return (-1);
        target[tarindex]   |=  (pos - Base64) >> 4;
        target[tarindex+1]  = ((pos - Base64) & 0x0f)
              << 4 ;
      }
      tarindex++;
      state = 2;
      break;
    case 2:
      if (target) {
        if (tarindex + 1 >= targsize)
          return (-1);
        target[tarindex]   |=  (pos - Base64) >> 2;
        target[tarindex+1]  = ((pos - Base64) & 0x03)
              << 6;
      }
      tarindex++;
      state = 3;
      break;
    case 3:
      if (target) {
        if (tarindex >= targsize)
          return (-1);
        target[tarindex] |= (pos - Base64);
      }
      tarindex++;
      state = 0;
      break;
    }
  }

  /*
   * We are done decoding Base-64 chars.  Let's see if we ended
   * on a byte boundary, and/or with erroneous trailing characters.
   */

  if (ch == Pad64) {   /* We got a pad char. */
    ch = *src++;    /* Skip it, get next. */
    switch (state) {
    case 0:   /* Invalid = in first position */
    case 1:   /* Invalid = in second position */
      return (-1);

    case 2:   /* Valid, means one byte of info */
      /* Skip any number of spaces. */
      for (; ch != '\0'; ch = *src++)
        if (!isspace(ch))
          break;
      /* Make sure there is another trailing = sign. */
      if (ch != Pad64)
        return (-1);
      ch = *src++;    /* Skip the = */
      /* Fall through to "single trailing =" case. */
      /* FALLTHROUGH */

    case 3:   /* Valid, means two bytes of info */
      /*
       * We know this char is an =.  Is there anything but
       * whitespace after it?
       */
      for (; ch != '\0'; ch = *src++)
        if (!isspace(ch))
          return (-1);

      /*
       * Now make sure for cases 2 and 3 that the "extra"
       * bits that slopped past the last full byte were
       * zeros.  If we don't check them, they become a
       * subliminal channel.
       */
      if (target && target[tarindex] != 0)
        return (-1);
    }
  } else {
    /*
     * We ended by seeing the end of the string.  Make sure we
     * have no partial bytes lying around.
     */
    if (state != 0)
      return (-1);
  }

  return (tarindex);
}

#endif /* !defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON) */
#endif 

Coverage Report

Created: 2026-10-23 07:09

Line	Count	Source
1		/* $OpenBSD: base64.c,v 1.5 2006/10/21 09:55:03 otto Exp $ */
2
3		/*
4		* Copyright (c) 1996 by Internet Software Consortium.
5		*
6		* Permission to use, copy, modify, and distribute this software for any
7		* purpose with or without fee is hereby granted, provided that the above
8		* copyright notice and this permission notice appear in all copies.
9		*
10		* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
11		* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
12		* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
13		* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
14		* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
15		* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
16		* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
17		* SOFTWARE.
18		*/
19
20		/*
21		* Portions Copyright (c) 1995 by International Business Machines, Inc.
22		*
23		* International Business Machines, Inc. (hereinafter called IBM) grants
24		* permission under its copyrights to use, copy, modify, and distribute this
25		* Software with or without fee, provided that the above copyright notice and
26		* all paragraphs of this notice appear in all copies, and that the name of IBM
27		* not be used in connection with the marketing of any product incorporating
28		* the Software or modifications thereof, without specific, written prior
29		* permission.
30		*
31		* To the extent it has a right to do so, IBM grants an immunity from suit
32		* under its patents, if any, for the use, sale or manufacture of products to
33		* the extent that such products are used for performing Domain Name System
34		* dynamic updates in TCP/IP networks by means of the Software. No immunity is
35		* granted for any product per se or for any other function of any product.
36		*
37		* THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES,
38		* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
39		* PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL,
40		* DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING
41		* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN
42		* IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES.
43		*/
44
45		/* OPENBSD ORIGINAL: lib/libc/net/base64.c */
46
47		#include "includes.h"
48
49		#if (!defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP)) \|\| (!defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON))
50
51		#include <sys/types.h>
52		#include <sys/socket.h>
53		#include <netinet/in.h>
54		#include <arpa/inet.h>
55
56		#include <ctype.h>
57		#include <stdio.h>
58
59		#include <stdlib.h>
60		#include <string.h>
61
62		#include "base64.h"
63
64		static const char Base64[] =
65		"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
66		static const char Pad64 = '=';
67
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
71		convenience.
72
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.)
76
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.
82
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
85		output string.
86
87		Table 1: The Base64 Alphabet
88
89		Value Encoding Value Encoding Value Encoding Value Encoding
90		0 A 17 R 34 i 51 z
91		1 B 18 S 35 j 52 0
92		2 C 19 T 36 k 53 1
93		3 D 20 U 37 l 54 2
94		4 E 21 V 38 m 55 3
95		5 F 22 W 39 n 56 4
96		6 G 23 X 40 o 57 5
97		7 H 24 Y 41 p 58 6
98		8 I 25 Z 42 q 59 7
99		9 J 26 a 43 r 60 8
100		10 K 27 b 44 s 61 9
101		11 L 28 c 45 t 62 +
102		12 M 29 d 46 u 63 /
103		13 N 30 e 47 v
104		14 O 31 f 48 w (pad) =
105		15 P 32 g 49 x
106		16 Q 33 h 50 y
107
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.
114
115		Since all base64 input is an integral number of octets, only the
116		-------------------------------------------------
117		following cases can arise:
118
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
122		with no "=" padding,
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.
129		*/
130
131		#if !defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP)
132		int
133		b64_ntop(u_char const src, size_t srclength, char target, size_t targsize)
134	33.9k	{
135	33.9k	size_t datalength = 0;
136	33.9k	u_char input[3];
137	33.9k	u_char output[4];
138	33.9k	u_int i;
139
140	237k	while (2 < srclength) {
141	203k	input[0] = *src++;
142	203k	input[1] = *src++;
143	203k	input[2] = *src++;
144	203k	srclength -= 3;
145
146	203k	output[0] = input[0] >> 2;
147	203k	output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
148	203k	output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
149	203k	output[3] = input[2] & 0x3f;
150
151	203k	if (datalength + 4 > targsize)
152	0	return (-1);
153	203k	target[datalength++] = Base64[output[0]];
154	203k	target[datalength++] = Base64[output[1]];
155	203k	target[datalength++] = Base64[output[2]];
156	203k	target[datalength++] = Base64[output[3]];
157	203k	}
158
159		/* Now we worry about padding. */
160	33.9k	if (0 != srclength) {
161		/* Get what's left. */
162	33.9k	input[0] = input[1] = input[2] = '\0';
163	101k	for (i = 0; i < srclength; i++)
164	67.8k	input[i] = *src++;
165
166	33.9k	output[0] = input[0] >> 2;
167	33.9k	output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
168	33.9k	output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
169
170	33.9k	if (datalength + 4 > targsize)
171	0	return (-1);
172	33.9k	target[datalength++] = Base64[output[0]];
173	33.9k	target[datalength++] = Base64[output[1]];
174	33.9k	if (srclength == 1)
175	0	target[datalength++] = Pad64;
176	33.9k	else
177	33.9k	target[datalength++] = Base64[output[2]];
178	33.9k	target[datalength++] = Pad64;
179	33.9k	}
180	33.9k	if (datalength >= targsize)
181	0	return (-1);
182	33.9k	target[datalength] = '\0'; /* Returned value doesn't count \0. */
183	33.9k	return (datalength);
184	33.9k	}
185		#endif /* !defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP) */
186
187		#if !defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON)
188
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.
193		*/
194
195		int
196		b64_pton(char const src, u_char target, size_t targsize)
197	28.6k	{
198	28.6k	u_int tarindex, state;
199	28.6k	int ch;
200	28.6k	char *pos;
201
202	28.6k	state = 0;
203	28.6k	tarindex = 0;
204
205	17.8M	while ((ch = *src++) != '\0') {
206	17.8M	if (isspace(ch)) /* Skip whitespace anywhere. */
207	2.03k	continue;
208
209	17.8M	if (ch == Pad64)
210	17.9k	break;
211
212	17.8M	pos = strchr(Base64, ch);
213	17.8M	if (pos == 0) /* A non-base64 character. */
214	2.76k	return (-1);
215
216	17.8M	switch (state) {
217	4.46M	case 0:
218	4.46M	if (target) {
219	4.46M	if (tarindex >= targsize)
220	0	return (-1);
221	4.46M	target[tarindex] = (pos - Base64) << 2;
222	4.46M	}
223	4.46M	state = 1;
224	4.46M	break;
225	4.46M	case 1:
226	4.46M	if (target) {
227	4.46M	if (tarindex + 1 >= targsize)
228	18	return (-1);
229	4.46M	target[tarindex] \|= (pos - Base64) >> 4;
230	4.46M	target[tarindex+1] = ((pos - Base64) & 0x0f)
231	4.46M	<< 4 ;
232	4.46M	}
233	4.46M	tarindex++;
234	4.46M	state = 2;
235	4.46M	break;
236	4.46M	case 2:
237	4.46M	if (target) {
238	4.46M	if (tarindex + 1 >= targsize)
239	0	return (-1);
240	4.46M	target[tarindex] \|= (pos - Base64) >> 2;
241	4.46M	target[tarindex+1] = ((pos - Base64) & 0x03)
242	4.46M	<< 6;
243	4.46M	}
244	4.46M	tarindex++;
245	4.46M	state = 3;
246	4.46M	break;
247	4.44M	case 3:
248	4.44M	if (target) {
249	4.44M	if (tarindex >= targsize)
250	0	return (-1);
251	4.44M	target[tarindex] \|= (pos - Base64);
252	4.44M	}
253	4.44M	tarindex++;
254	4.44M	state = 0;
255	4.44M	break;
256	17.8M	}
257	17.8M	}
258
259		/*
260		* We are done decoding Base-64 chars. Let's see if we ended
261		* on a byte boundary, and/or with erroneous trailing characters.
262		*/
263
264	25.8k	if (ch == Pad64) { /* We got a pad char. */
265	17.9k	ch = src++; / Skip it, get next. */
266	17.9k	switch (state) {
267	201	case 0: /* Invalid = in first position */
268	353	case 1: /* Invalid = in second position */
269	353	return (-1);
270
271	171	case 2: /* Valid, means one byte of info */
272		/* Skip any number of spaces. */
273	222	for (; ch != '\0'; ch = *src++)
274	89	if (!isspace(ch))
275	38	break;
276		/* Make sure there is another trailing = sign. */
277	171	if (ch != Pad64)
278	145	return (-1);
279	26	ch = src++; / Skip the = */
280		/* Fall through to "single trailing =" case. */
281		/* FALLTHROUGH */
282
283	17.4k	case 3: /* Valid, means two bytes of info */
284		/*
285		* We know this char is an =. Is there anything but
286		* whitespace after it?
287		*/
288	17.5k	for (; ch != '\0'; ch = *src++)
289	126	if (!isspace(ch))
290	11	return (-1);
291
292		/*
293		* Now make sure for cases 2 and 3 that the "extra"
294		* bits that slopped past the last full byte were
295		* zeros. If we don't check them, they become a
296		* subliminal channel.
297		*/
298	17.4k	if (target && target[tarindex] != 0)
299	16	return (-1);
300	17.9k	}
301	17.9k	} else {
302		/*
303		* We ended by seeing the end of the string. Make sure we
304		* have no partial bytes lying around.
305		*/
306	7.95k	if (state != 0)
307	1.47k	return (-1);
308	7.95k	}
309
310	23.8k	return (tarindex);
311	25.8k	}
312
313		#endif /* !defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON) */
314		#endif