[gssapi-openssh.git] / openssh / openbsd-compat / base64.c

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

/*	$OpenBSD: base64.c,v 1.4 2002/01/02 23:00:10 deraadt 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.
 */

#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/param.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"

/* XXX abort illegal in library */
#define Assert(Cond) if (!(Cond)) abort()

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];
	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;
		Assert(output[0] < 64);
		Assert(output[1] < 64);
		Assert(output[2] < 64);
		Assert(output[3] < 64);

		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);
		Assert(output[0] < 64);
		Assert(output[1] < 64);
		Assert(output[2] < 64);

		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)
{
	int tarindex, state, 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
Commit	Line	Data
12408a1b	1	/* OPENBSD ORIGINAL: lib/libc/net/base64.c */
12408a1b	2
41b2f314	3	/* $OpenBSD: base64.c,v 1.4 2002/01/02 23:00:10 deraadt Exp $ */
3c0ef626	4
	5	/*
	6	* Copyright (c) 1996 by Internet Software Consortium.
	7	*
	8	* Permission to use, copy, modify, and distribute this software for any
	9	* purpose with or without fee is hereby granted, provided that the above
	10	* copyright notice and this permission notice appear in all copies.
	11	*
	12	* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
	13	* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
	14	* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
	15	* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
	16	* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
	17	* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
	18	* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
	19	* SOFTWARE.
	20	*/
	21
	22	/*
	23	* Portions Copyright (c) 1995 by International Business Machines, Inc.
	24	*
	25	* International Business Machines, Inc. (hereinafter called IBM) grants
	26	* permission under its copyrights to use, copy, modify, and distribute this
	27	* Software with or without fee, provided that the above copyright notice and
	28	* all paragraphs of this notice appear in all copies, and that the name of IBM
	29	* not be used in connection with the marketing of any product incorporating
	30	* the Software or modifications thereof, without specific, written prior
	31	* permission.
	32	*
	33	* To the extent it has a right to do so, IBM grants an immunity from suit
	34	* under its patents, if any, for the use, sale or manufacture of products to
	35	* the extent that such products are used for performing Domain Name System
	36	* dynamic updates in TCP/IP networks by means of the Software. No immunity is
	37	* granted for any product per se or for any other function of any product.
	38	*
	39	* THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES,
	40	* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
	41	* PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL,
	42	* DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING
	43	* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN
	44	* IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES.
	45	*/
	46
41b2f314	47	#include "includes.h"
3c0ef626	48
6a9b3198	49	#if (!defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP)) \|\| (!defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON))
3c0ef626	50
	51	#include <sys/types.h>
	52	#include <sys/param.h>
	53	#include <sys/socket.h>
	54	#include <netinet/in.h>
	55	#include <arpa/inet.h>
	56
	57	#include <ctype.h>
	58	#include <stdio.h>
	59
	60	#include <stdlib.h>
	61	#include <string.h>
	62
	63	#include "base64.h"
	64
41b2f314	65	/* XXX abort illegal in library */
3c0ef626	66	#define Assert(Cond) if (!(Cond)) abort()
	67
	68	static const char Base64[] =
	69	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
	70	static const char Pad64 = '=';
	71
	72	/* (From RFC1521 and draft-ietf-dnssec-secext-03.txt)
	73	The following encoding technique is taken from RFC 1521 by Borenstein
	74	and Freed. It is reproduced here in a slightly edited form for
	75	convenience.
	76
	77	A 65-character subset of US-ASCII is used, enabling 6 bits to be
	78	represented per printable character. (The extra 65th character, "=",
	79	is used to signify a special processing function.)
	80
	81	The encoding process represents 24-bit groups of input bits as output
	82	strings of 4 encoded characters. Proceeding from left to right, a
	83	24-bit input group is formed by concatenating 3 8-bit input groups.
	84	These 24 bits are then treated as 4 concatenated 6-bit groups, each
	85	of which is translated into a single digit in the base64 alphabet.
	86
	87	Each 6-bit group is used as an index into an array of 64 printable
	88	characters. The character referenced by the index is placed in the
	89	output string.
	90
	91	Table 1: The Base64 Alphabet
	92
	93	Value Encoding Value Encoding Value Encoding Value Encoding
	94	0 A 17 R 34 i 51 z
	95	1 B 18 S 35 j 52 0
	96	2 C 19 T 36 k 53 1
	97	3 D 20 U 37 l 54 2
	98	4 E 21 V 38 m 55 3
	99	5 F 22 W 39 n 56 4
	100	6 G 23 X 40 o 57 5
	101	7 H 24 Y 41 p 58 6
	102	8 I 25 Z 42 q 59 7
	103	9 J 26 a 43 r 60 8
	104	10 K 27 b 44 s 61 9
	105	11 L 28 c 45 t 62 +
	106	12 M 29 d 46 u 63 /
	107	13 N 30 e 47 v
	108	14 O 31 f 48 w (pad) =
	109	15 P 32 g 49 x
	110	16 Q 33 h 50 y
	111
	112	Special processing is performed if fewer than 24 bits are available
	113	at the end of the data being encoded. A full encoding quantum is
	114	always completed at the end of a quantity. When fewer than 24 input
	115	bits are available in an input group, zero bits are added (on the
	116	right) to form an integral number of 6-bit groups. Padding at the
	117	end of the data is performed using the '=' character.
	118
	119	Since all base64 input is an integral number of octets, only the
	120	-------------------------------------------------
	121	following cases can arise:
	122
	123	(1) the final quantum of encoding input is an integral
	124	multiple of 24 bits; here, the final unit of encoded
	125	output will be an integral multiple of 4 characters
	126	with no "=" padding,
	127	(2) the final quantum of encoding input is exactly 8 bits;
	128	here, the final unit of encoded output will be two
	129	characters followed by two "=" padding characters, or
130	(3) the final quantum of encoding input is exactly 16 bits;
131	here, the final unit of encoded output will be three
132	characters followed by one "=" padding character.
133	*/
134
6a9b3198	135	#if !defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP)
3c0ef626	136	int
	137	b64_ntop(u_char const src, size_t srclength, char target, size_t targsize)
	138	{
	139	size_t datalength = 0;
	140	u_char input[3];
	141	u_char output[4];
	142	int i;
	143
	144	while (2 < srclength) {
	145	input[0] = *src++;
	146	input[1] = *src++;
	147	input[2] = *src++;
	148	srclength -= 3;
	149
	150	output[0] = input[0] >> 2;
	151	output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
	152	output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
	153	output[3] = input[2] & 0x3f;
	154	Assert(output[0] < 64);
	155	Assert(output[1] < 64);
	156	Assert(output[2] < 64);
	157	Assert(output[3] < 64);
	158
	159	if (datalength + 4 > targsize)
	160	return (-1);
	161	target[datalength++] = Base64[output[0]];
	162	target[datalength++] = Base64[output[1]];
	163	target[datalength++] = Base64[output[2]];
	164	target[datalength++] = Base64[output[3]];
	165	}
	166
	167	/* Now we worry about padding. */
	168	if (0 != srclength) {
	169	/* Get what's left. */
	170	input[0] = input[1] = input[2] = '\0';
	171	for (i = 0; i < srclength; i++)
	172	input[i] = *src++;
	173
	174	output[0] = input[0] >> 2;
	175	output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
	176	output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
	177	Assert(output[0] < 64);
	178	Assert(output[1] < 64);
	179	Assert(output[2] < 64);
	180
	181	if (datalength + 4 > targsize)
	182	return (-1);
	183	target[datalength++] = Base64[output[0]];
	184	target[datalength++] = Base64[output[1]];
	185	if (srclength == 1)
	186	target[datalength++] = Pad64;
	187	else
	188	target[datalength++] = Base64[output[2]];
	189	target[datalength++] = Pad64;
	190	}
	191	if (datalength >= targsize)
	192	return (-1);
	193	target[datalength] = '\0'; /* Returned value doesn't count \0. */
	194	return (datalength);
	195	}
6a9b3198	196	#endif /* !defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP) */
	197
	198	#if !defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON)
3c0ef626	199
	200	/* skips all whitespace anywhere.
	201	converts characters, four at a time, starting at (or after)
	202	src from base - 64 numbers into three 8 bit bytes in the target area.
	203	it returns the number of data bytes stored at the target, or -1 on error.
	204	*/
	205
	206	int
	207	b64_pton(char const src, u_char target, size_t targsize)
	208	{
	209	int tarindex, state, ch;
	210	char *pos;
	211
	212	state = 0;
	213	tarindex = 0;
	214
	215	while ((ch = *src++) != '\0') {
	216	if (isspace(ch)) /* Skip whitespace anywhere. */
	217	continue;
	218
	219	if (ch == Pad64)
	220	break;
	221
	222	pos = strchr(Base64, ch);
	223	if (pos == 0) /* A non-base64 character. */
	224	return (-1);
	225
	226	switch (state) {
	227	case 0:
	228	if (target) {
	229	if (tarindex >= targsize)
	230	return (-1);
	231	target[tarindex] = (pos - Base64) << 2;
	232	}
	233	state = 1;
	234	break;
	235	case 1:
	236	if (target) {
	237	if (tarindex + 1 >= targsize)
	238	return (-1);
	239	target[tarindex] \|= (pos - Base64) >> 4;
	240	target[tarindex+1] = ((pos - Base64) & 0x0f)
	241	<< 4 ;
	242	}
	243	tarindex++;
	244	state = 2;
	245	break;
	246	case 2:
	247	if (target) {
	248	if (tarindex + 1 >= targsize)
	249	return (-1);
	250	target[tarindex] \|= (pos - Base64) >> 2;
	251	target[tarindex+1] = ((pos - Base64) & 0x03)
	252	<< 6;
	253	}
	254	tarindex++;
	255	state = 3;
	256	break;
	257	case 3:
	258	if (target) {
	259	if (tarindex >= targsize)
	260	return (-1);
	261	target[tarindex] \|= (pos - Base64);
	262	}
263	tarindex++;
264	state = 0;
265	break;
266	}
267	}
268
269	/*
270	* We are done decoding Base-64 chars. Let's see if we ended
271	* on a byte boundary, and/or with erroneous trailing characters.
272	*/
273
274	if (ch == Pad64) { /* We got a pad char. */
275	ch = src++; / Skip it, get next. */
276	switch (state) {
277	case 0: /* Invalid = in first position */
278	case 1: /* Invalid = in second position */
279	return (-1);
280
281	case 2: /* Valid, means one byte of info */
282	/* Skip any number of spaces. */
283	for (; ch != '\0'; ch = *src++)
284	if (!isspace(ch))
285	break;
286	/* Make sure there is another trailing = sign. */
287	if (ch != Pad64)
288	return (-1);
289	ch = src++; / Skip the = */
290	/* Fall through to "single trailing =" case. */
291	/* FALLTHROUGH */
292
293	case 3: /* Valid, means two bytes of info */
294	/*
295	* We know this char is an =. Is there anything but
296	* whitespace after it?
297	*/
298	for (; ch != '\0'; ch = *src++)
299	if (!isspace(ch))
300	return (-1);
301
302	/*
303	* Now make sure for cases 2 and 3 that the "extra"
304	* bits that slopped past the last full byte were
305	* zeros. If we don't check them, they become a
306	* subliminal channel.
307	*/
308	if (target && target[tarindex] != 0)
309	return (-1);
310	}
311	} else {
312	/*
313	* We ended by seeing the end of the string. Make sure we
314	* have no partial bytes lying around.
315	*/
316	if (state != 0)
317	return (-1);
318	}
319
320	return (tarindex);
321	}
322
6a9b3198	323	#endif /* !defined(HAVE_B64_PTON) && !defined(HAVE___B64_PTON) */
6a9b3198	324	#endif