GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libc/net/base64.c Lines: 0 93 0.0 %
Date: 2017-11-07 Branches: 0 76 0.0 %

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/*	$OpenBSD: base64.c,v 1.8 2015/01/16 16:48:51 deraadt Exp $	*/
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/*
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 * Copyright (c) 1996 by Internet Software Consortium.
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 *
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 * Permission to use, copy, modify, and distribute this software for any
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 * purpose with or without fee is hereby granted, provided that the above
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 * copyright notice and this permission notice appear in all copies.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
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 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
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 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
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 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
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 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
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 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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 * SOFTWARE.
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 */
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/*
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 * Portions Copyright (c) 1995 by International Business Machines, Inc.
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 *
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 * International Business Machines, Inc. (hereinafter called IBM) grants
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 * permission under its copyrights to use, copy, modify, and distribute this
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 * Software with or without fee, provided that the above copyright notice and
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 * all paragraphs of this notice appear in all copies, and that the name of IBM
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 * not be used in connection with the marketing of any product incorporating
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 * the Software or modifications thereof, without specific, written prior
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 * permission.
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 *
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 * To the extent it has a right to do so, IBM grants an immunity from suit
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 * under its patents, if any, for the use, sale or manufacture of products to
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 * the extent that such products are used for performing Domain Name System
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 * dynamic updates in TCP/IP networks by means of the Software.  No immunity is
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 * granted for any product per se or for any other function of any product.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES,
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 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
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 * PARTICULAR PURPOSE.  IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL,
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 * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING
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 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN
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 * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES.
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 */
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <arpa/nameser.h>
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#include <ctype.h>
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#include <resolv.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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static const char Base64[] =
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	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
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static const char Pad64 = '=';
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/* (From RFC1521 and draft-ietf-dnssec-secext-03.txt)
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   The following encoding technique is taken from RFC 1521 by Borenstein
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   and Freed.  It is reproduced here in a slightly edited form for
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   convenience.
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   A 65-character subset of US-ASCII is used, enabling 6 bits to be
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   represented per printable character. (The extra 65th character, "=",
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   is used to signify a special processing function.)
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   The encoding process represents 24-bit groups of input bits as output
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   strings of 4 encoded characters. Proceeding from left to right, a
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   24-bit input group is formed by concatenating 3 8-bit input groups.
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   These 24 bits are then treated as 4 concatenated 6-bit groups, each
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   of which is translated into a single digit in the base64 alphabet.
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   Each 6-bit group is used as an index into an array of 64 printable
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   characters. The character referenced by the index is placed in the
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   output string.
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                         Table 1: The Base64 Alphabet
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      Value Encoding  Value Encoding  Value Encoding  Value Encoding
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          0 A            17 R            34 i            51 z
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          1 B            18 S            35 j            52 0
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          2 C            19 T            36 k            53 1
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          3 D            20 U            37 l            54 2
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          4 E            21 V            38 m            55 3
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          5 F            22 W            39 n            56 4
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          6 G            23 X            40 o            57 5
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          7 H            24 Y            41 p            58 6
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          8 I            25 Z            42 q            59 7
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          9 J            26 a            43 r            60 8
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         10 K            27 b            44 s            61 9
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         11 L            28 c            45 t            62 +
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         12 M            29 d            46 u            63 /
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         13 N            30 e            47 v
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         14 O            31 f            48 w         (pad) =
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         15 P            32 g            49 x
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         16 Q            33 h            50 y
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   Special processing is performed if fewer than 24 bits are available
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   at the end of the data being encoded.  A full encoding quantum is
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   always completed at the end of a quantity.  When fewer than 24 input
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   bits are available in an input group, zero bits are added (on the
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   right) to form an integral number of 6-bit groups.  Padding at the
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   end of the data is performed using the '=' character.
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   Since all base64 input is an integral number of octets, only the
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         -------------------------------------------------
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   following cases can arise:
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       (1) the final quantum of encoding input is an integral
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           multiple of 24 bits; here, the final unit of encoded
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	   output will be an integral multiple of 4 characters
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	   with no "=" padding,
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       (2) the final quantum of encoding input is exactly 8 bits;
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           here, the final unit of encoded output will be two
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	   characters followed by two "=" padding characters, or
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       (3) the final quantum of encoding input is exactly 16 bits;
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           here, the final unit of encoded output will be three
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	   characters followed by one "=" padding character.
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   */
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int
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b64_ntop(src, srclength, target, targsize)
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	u_char const *src;
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	size_t srclength;
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	char *target;
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	size_t targsize;
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{
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	size_t datalength = 0;
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	u_char input[3];
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	u_char output[4];
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	int i;
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	while (2 < srclength) {
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		input[0] = *src++;
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		input[1] = *src++;
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		input[2] = *src++;
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		srclength -= 3;
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		output[0] = input[0] >> 2;
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		output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
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		output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
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		output[3] = input[2] & 0x3f;
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		if (datalength + 4 > targsize)
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			return (-1);
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		target[datalength++] = Base64[output[0]];
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		target[datalength++] = Base64[output[1]];
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		target[datalength++] = Base64[output[2]];
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		target[datalength++] = Base64[output[3]];
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	}
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	/* Now we worry about padding. */
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	if (0 != srclength) {
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		/* Get what's left. */
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		input[0] = input[1] = input[2] = '\0';
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		for (i = 0; i < srclength; i++)
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			input[i] = *src++;
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		output[0] = input[0] >> 2;
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		output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
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		output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
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		if (datalength + 4 > targsize)
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			return (-1);
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		target[datalength++] = Base64[output[0]];
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		target[datalength++] = Base64[output[1]];
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		if (srclength == 1)
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			target[datalength++] = Pad64;
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		else
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			target[datalength++] = Base64[output[2]];
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		target[datalength++] = Pad64;
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	}
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	if (datalength >= targsize)
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		return (-1);
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	target[datalength] = '\0';	/* Returned value doesn't count \0. */
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	return (datalength);
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}
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/* skips all whitespace anywhere.
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   converts characters, four at a time, starting at (or after)
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   src from base - 64 numbers into three 8 bit bytes in the target area.
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   it returns the number of data bytes stored at the target, or -1 on error.
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 */
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int
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b64_pton(src, target, targsize)
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	char const *src;
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	u_char *target;
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	size_t targsize;
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{
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	int tarindex, state, ch;
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	u_char nextbyte;
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	char *pos;
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	state = 0;
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	tarindex = 0;
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	while ((ch = (unsigned char)*src++) != '\0') {
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		if (isspace(ch))	/* Skip whitespace anywhere. */
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			continue;
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		if (ch == Pad64)
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			break;
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		pos = strchr(Base64, ch);
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		if (pos == 0) 		/* A non-base64 character. */
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			return (-1);
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		switch (state) {
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		case 0:
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			if (target) {
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				if (tarindex >= targsize)
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					return (-1);
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				target[tarindex] = (pos - Base64) << 2;
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			}
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			state = 1;
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			break;
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		case 1:
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			if (target) {
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				if (tarindex >= targsize)
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					return (-1);
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				target[tarindex]   |=  (pos - Base64) >> 4;
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				nextbyte = ((pos - Base64) & 0x0f) << 4;
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				if (tarindex + 1 < targsize)
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					target[tarindex+1] = nextbyte;
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				else if (nextbyte)
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					return (-1);
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			}
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			tarindex++;
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			state = 2;
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			break;
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		case 2:
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			if (target) {
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				if (tarindex >= targsize)
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					return (-1);
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				target[tarindex]   |=  (pos - Base64) >> 2;
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				nextbyte = ((pos - Base64) & 0x03) << 6;
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				if (tarindex + 1 < targsize)
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					target[tarindex+1] = nextbyte;
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				else if (nextbyte)
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					return (-1);
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			}
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			tarindex++;
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			state = 3;
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			break;
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		case 3:
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			if (target) {
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				if (tarindex >= targsize)
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					return (-1);
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				target[tarindex] |= (pos - Base64);
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			}
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			tarindex++;
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			state = 0;
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			break;
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		}
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	}
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	/*
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	 * We are done decoding Base-64 chars.  Let's see if we ended
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	 * on a byte boundary, and/or with erroneous trailing characters.
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	 */
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	if (ch == Pad64) {			/* We got a pad char. */
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		ch = (unsigned char)*src++;	/* Skip it, get next. */
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		switch (state) {
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		case 0:		/* Invalid = in first position */
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		case 1:		/* Invalid = in second position */
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			return (-1);
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		case 2:		/* Valid, means one byte of info */
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			/* Skip any number of spaces. */
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			for (; ch != '\0'; ch = (unsigned char)*src++)
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				if (!isspace(ch))
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					break;
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			/* Make sure there is another trailing = sign. */
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			if (ch != Pad64)
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				return (-1);
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			ch = (unsigned char)*src++;		/* Skip the = */
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			/* Fall through to "single trailing =" case. */
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			/* FALLTHROUGH */
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		case 3:		/* Valid, means two bytes of info */
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			/*
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			 * We know this char is an =.  Is there anything but
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			 * whitespace after it?
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			 */
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			for (; ch != '\0'; ch = (unsigned char)*src++)
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				if (!isspace(ch))
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					return (-1);
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			/*
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			 * Now make sure for cases 2 and 3 that the "extra"
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			 * bits that slopped past the last full byte were
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			 * zeros.  If we don't check them, they become a
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			 * subliminal channel.
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			 */
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			if (target && tarindex < targsize &&
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			    target[tarindex] != 0)
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				return (-1);
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		}
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	} else {
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		/*
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		 * We ended by seeing the end of the string.  Make sure we
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		 * have no partial bytes lying around.
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		 */
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		if (state != 0)
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			return (-1);
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	}
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	return (tarindex);
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}