libc/netbsd/net/base64.c - platform/bionic - Git at Google

 /*	$NetBSD: base64.c,v 1.8 2002/11/11 01:15:17 thorpej 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 <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
 __RCSID("$NetBSD: base64.c,v 1.8 2002/11/11 01:15:17 thorpej Exp $");
 #endif /* LIBC_SCCS and not lint */

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

 #include <assert.h>
 #include <ctype.h>
 #ifdef ANDROID_CHANGES
 #include "resolv_private.h"
 #else
 #include <resolv.h>
 #endif
 #include <stdio.h>

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

 int
 b64_ntop(src, srclength, target, targsize)
 	u_char const *src;
 	size_t srclength;
 	char *target;
 	size_t targsize;
 {
 	size_t datalength = 0;
 	u_char input[3] = { 0, 0, 0 };  /* make compiler happy */
 	u_char output[4];
 	size_t i;

 	assert(src != NULL);
 	assert(target != NULL);

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

 		output[0] = (u_int32_t)input[0] >> 2;
 		output[1] = ((u_int32_t)(input[0] & 0x03) << 4) +
 		    ((u_int32_t)input[1] >> 4);
 		output[2] = ((u_int32_t)(input[1] & 0x0f) << 2) +
 		    ((u_int32_t)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] = (u_int32_t)input[0] >> 2;
 		output[1] = ((u_int32_t)(input[0] & 0x03) << 4) +
 		    ((u_int32_t)input[1] >> 4);
 		output[2] = ((u_int32_t)(input[1] & 0x0f) << 2) +
 		    ((u_int32_t)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);
 }

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

 	assert(src != NULL);
 	assert(target != NULL);

 	state = 0;
 	tarindex = 0;

 	while ((ch = (u_char) *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] |=
 				    (u_int32_t)(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] |=
 					(u_int32_t)(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;
 		default:
 			abort();
 		}
 	}

 	/*
 	 * 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 = (u_char) *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 = (u_char) *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);
 }
	/* $NetBSD: base64.c,v 1.8 2002/11/11 01:15:17 thorpej 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 <sys/cdefs.h>
	#if defined(LIBC_SCCS) && !defined(lint)
	__RCSID("$NetBSD: base64.c,v 1.8 2002/11/11 01:15:17 thorpej Exp $");
	#endif /* LIBC_SCCS and not lint */

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

	#include <assert.h>
	#include <ctype.h>
	#ifdef ANDROID_CHANGES
	#include "resolv_private.h"
	#else
	#include <resolv.h>
	#endif
	#include <stdio.h>

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

	int
	b64_ntop(src, srclength, target, targsize)
	u_char const *src;
	size_t srclength;
	char *target;
	size_t targsize;
	{
	size_t datalength = 0;
	u_char input[3] = { 0, 0, 0 }; /* make compiler happy */
	u_char output[4];
	size_t i;

	assert(src != NULL);
	assert(target != NULL);

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

	output[0] = (u_int32_t)input[0] >> 2;
	output[1] = ((u_int32_t)(input[0] & 0x03) << 4) +
	((u_int32_t)input[1] >> 4);
	output[2] = ((u_int32_t)(input[1] & 0x0f) << 2) +
	((u_int32_t)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] = (u_int32_t)input[0] >> 2;
	output[1] = ((u_int32_t)(input[0] & 0x03) << 4) +
	((u_int32_t)input[1] >> 4);
	output[2] = ((u_int32_t)(input[1] & 0x0f) << 2) +
	((u_int32_t)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);
	}

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

	assert(src != NULL);
	assert(target != NULL);

	state = 0;
	tarindex = 0;

	while ((ch = (u_char) *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] \|=
	(u_int32_t)(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] \|=
	(u_int32_t)(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;
	default:
	abort();
	}
	}

	/*
	* 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 = (u_char) *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 = (u_char) *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);
	}