Return to uudecode.c CVS log

Up to [local] / src / usr.bin / uudecode

Replace <sys/param.h> with <limits.h> and other less dirty headers where
possible.  Annotate <sys/param.h> lines with their current reasons.  Switch
to PATH_MAX, NGROUPS_MAX, HOST_NAME_MAX+1, LOGIN_NAME_MAX, etc.  Change
MIN() and MAX() to local definitions of MINIMUM() and MAXIMUM() where
sensible to avoid pulling in the pollution.  These are the files confirmed
through binary verification.
ok guenther, millert, doug (helped with the verification protocol)

/*	$OpenBSD: uudecode.c,v 1.20 2015/01/16 06:40:13 deraadt Exp $	*/
/*	$FreeBSD: uudecode.c,v 1.49 2003/05/03 19:44:46 obrien Exp $	*/

/*-
 * Copyright (c) 1983, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Create the specified file, decoding as you go.
 * Used with uuencode.
 */

#include <sys/socket.h>
#include <sys/stat.h>

#include <netinet/in.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <locale.h>
#include <pwd.h>
#include <resolv.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>

static const char *infile, *outfile;
static FILE *infp, *outfp;
static int base64, cflag, iflag, oflag, pflag, rflag, sflag;

static void	usage(void);
static int	decode(void);
static int	decode2(void);
static int	uu_decode(void);
static int	base64_decode(void);

enum program_mode {
	MODE_DECODE,
	MODE_B64DECODE
} pmode;

int
main(int argc, char *argv[])
{
	int rval, ch;
	extern char *__progname;
	static const char *optstr[2] = {
		"cimo:prs",
		"cio:prs"
	};

	pmode = MODE_DECODE;
	if (strcmp(__progname, "b64decode") == 0) {
		base64 = 1;
		pmode = MODE_B64DECODE;
	}

	setlocale(LC_ALL, "");
	while ((ch = getopt(argc, argv, optstr[pmode])) != -1) {
		switch(ch) {
		case 'c':
			if (oflag || rflag)
				usage();
			cflag = 1; /* multiple uudecode'd files */
			break;
		case 'i':
			iflag = 1; /* ask before override files */
			break;
		case 'm':
			base64 = 1;
			break;
		case 'o':
			if (cflag || pflag || rflag || sflag)
				usage();
			oflag = 1; /* output to the specified file */
			sflag = 1; /* do not strip pathnames for output */
			outfile = optarg; /* set the output filename */
			break;
		case 'p':
			if (oflag)
				usage();
			pflag = 1; /* print output to stdout */
			break;
		case 'r':
			if (cflag || oflag)
				usage();
			rflag = 1; /* decode raw data */
			break;
		case 's':
			if (oflag)
				usage();
			sflag = 1; /* do not strip pathnames for output */
			break;
		default:
			usage();
		}
	}
	argc -= optind;
	argv += optind;

	if (*argv) {
		rval = 0;
		do {
			infp = fopen(infile = *argv, "r");
			if (infp == NULL) {
				warn("%s", *argv);
				rval = 1;
				continue;
			}
			rval |= decode();
			fclose(infp);
		} while (*++argv);
	} else {
		infile = "stdin";
		infp = stdin;
		rval = decode();
	}
	exit(rval);
}

static int
decode(void)
{
	int r, v;

	if (rflag) {
		/* relaxed alternative to decode2() */
		outfile = "/dev/stdout";
		outfp = stdout;
		if (base64)
			return (base64_decode());
		else
			return (uu_decode());
	}
	v = decode2();
	if (v == EOF) {
		warnx("%s: missing or bad \"begin\" line", infile);
		return (1);
	}
	for (r = v; cflag; r |= v) {
		v = decode2();
		if (v == EOF)
			break;
	}
	return (r);
}

static int
decode2(void)
{
	int flags, fd, mode;
	size_t n, m;
	char *p, *q;
	void *handle;
	struct passwd *pw;
	struct stat st;
	char buf[PATH_MAX];

	base64 = 0;
	/* search for header line */
	for (;;) {
		if (fgets(buf, sizeof(buf), infp) == NULL)
			return (EOF);
		p = buf;
		if (strncmp(p, "begin-base64 ", 13) == 0) {
			base64 = 1;
			p += 13;
		} else if (strncmp(p, "begin ", 6) == 0)
			p += 6;
		else
			continue;
		/* p points to mode */
		q = strchr(p, ' ');
		if (q == NULL)
			continue;
		*q++ = '\0';
		/* q points to filename */
		n = strlen(q);
		while (n > 0 && (q[n-1] == '\n' || q[n-1] == '\r'))
			q[--n] = '\0';
		/* found valid header? */
		if (n > 0)
			break;
	}

	handle = setmode(p);
	if (handle == NULL) {
		warnx("%s: unable to parse file mode", infile);
		return (1);
	}
	mode = getmode(handle, 0) & 0666;
	free(handle);

	if (sflag) {
		/* don't strip, so try ~user/file expansion */
		p = NULL;
		pw = NULL;
		if (*q == '~')
			p = strchr(q, '/');
		if (p != NULL) {
			*p = '\0';
			pw = getpwnam(q + 1);
			*p = '/';
		}
		if (pw != NULL) {
			n = strlen(pw->pw_dir);
			if (buf + n > p) {
				/* make room */
				m = strlen(p);
				if (sizeof(buf) < n + m) {
					warnx("%s: bad output filename",
					    infile);
					return (1);
				}
				p = memmove(buf + n, p, m);
			}
			q = memcpy(p - n, pw->pw_dir, n);
		}
	} else {
		/* strip down to leaf name */
		p = strrchr(q, '/');
		if (p != NULL)
			q = p + 1;
	}
	if (!oflag)
		outfile = q;

	/* POSIX says "/dev/stdout" is a 'magic cookie' not a special file. */
	if (pflag || strcmp(outfile, "/dev/stdout") == 0)
		outfp = stdout;
	else {
		flags = O_WRONLY|O_CREAT|O_EXCL|O_NOFOLLOW;
		if (lstat(outfile, &st) == 0) {
			if (iflag) {
				warnc(EEXIST, "%s: %s", infile, outfile);
				return (0);
			}
			switch (st.st_mode & S_IFMT) {
			case S_IFREG:
			case S_IFLNK:
				/* avoid symlink attacks */
				if (unlink(outfile) == 0 || errno == ENOENT)
					break;
				warn("%s: unlink %s", infile, outfile);
				return (1);
			case S_IFDIR:
				warnc(EISDIR, "%s: %s", infile, outfile);
				return (1);
			default:
				if (oflag) {
					/* trust command-line names */
					flags &= ~(O_EXCL|O_NOFOLLOW);
					break;
				}
				warnc(EEXIST, "%s: %s", infile, outfile);
				return (1);
			}
		} else if (errno != ENOENT) {
			warn("%s: %s", infile, outfile);
			return (1);
		}
		if ((fd = open(outfile, flags, mode)) < 0 ||
		    (outfp = fdopen(fd, "w")) == NULL) {
			warn("%s: %s", infile, outfile);
			return (1);
		}
	}

	if (base64)
		return (base64_decode());
	else
		return (uu_decode());
}

static int
get_line(char *buf, size_t size)
{
	if (fgets(buf, size, infp) != NULL)
		return (2);
	if (rflag)
		return (0);
	warnx("%s: %s: short file", infile, outfile);
	return (1);
}

static int
checkend(const char *ptr, const char *end, const char *msg)
{
	size_t n;

	n = strlen(end);
	if (strncmp(ptr, end, n) != 0 ||
	    strspn(ptr + n, " \t\r\n") != strlen(ptr + n)) {
		warnx("%s: %s: %s", infile, outfile, msg);
		return (1);
	}
	if (fclose(outfp) != 0) {
		warn("%s: %s", infile, outfile);
		return (1);
	}
	return (0);
}

static int
uu_decode(void)
{
	int i, ch;
	char *p;
	char buf[PATH_MAX];

	/* for each input line */
	for (;;) {
		switch (get_line(buf, sizeof(buf))) {
		case 0:
			return (0);
		case 1:
			return (1);
		}

#define	DEC(c)	(((c) - ' ') & 077)		/* single character decode */
#define IS_DEC(c) ( (((c) - ' ') >= 0) && (((c) - ' ') <= 077 + 1) )

#define OUT_OF_RANGE do {						\
	warnx("%s: %s: character out of range: [%d-%d]",		\
	    infile, outfile, 1 + ' ', 077 + ' ' + 1);			\
	return (1);							\
} while (0)

		/*
		 * `i' is used to avoid writing out all the characters
		 * at the end of the file.
		 */
		p = buf;
		if ((i = DEC(*p)) <= 0)
			break;
		for (++p; i > 0; p += 4, i -= 3)
			if (i >= 3) {
				if (!(IS_DEC(*p) && IS_DEC(*(p + 1)) &&
				     IS_DEC(*(p + 2)) && IS_DEC(*(p + 3))))
					OUT_OF_RANGE;

				ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
				putc(ch, outfp);
				ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
				putc(ch, outfp);
				ch = DEC(p[2]) << 6 | DEC(p[3]);
				putc(ch, outfp);
			}
			else {
				if (i >= 1) {
					if (!(IS_DEC(*p) && IS_DEC(*(p + 1))))
						OUT_OF_RANGE;
					ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
					putc(ch, outfp);
				}
				if (i >= 2) {
					if (!(IS_DEC(*(p + 1)) &&
					    IS_DEC(*(p + 2))))
						OUT_OF_RANGE;

					ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
					putc(ch, outfp);
				}
				if (i >= 3) {
					if (!(IS_DEC(*(p + 2)) &&
					    IS_DEC(*(p + 3))))
						OUT_OF_RANGE;
					ch = DEC(p[2]) << 6 | DEC(p[3]);
					putc(ch, outfp);
				}
			}
	}
	switch (get_line(buf, sizeof(buf))) {
	case 0:
		return (0);
	case 1:
		return (1);
	default:
		return (checkend(buf, "end", "no \"end\" line"));
	}
}

static int
base64_decode(void)
{
	int n;
	char inbuf[PATH_MAX];
	unsigned char outbuf[PATH_MAX * 4];

	for (;;) {
		switch (get_line(inbuf, sizeof(inbuf))) {
		case 0:
			return (0);
		case 1:
			return (1);
		}
		n = b64_pton(inbuf, outbuf, sizeof(outbuf));
		if (n < 0)
			break;
		fwrite(outbuf, 1, n, outfp);
	}
	return (checkend(inbuf, "====",
		    "error decoding base64 input stream"));
}

static void
usage(void)
{
	switch (pmode) {
	case MODE_DECODE:
		(void)fprintf(stderr,
		    "usage: uudecode [-cimprs] [file ...]\n"
		    "       uudecode [-i] -o output_file [file]\n");
		break;
	case MODE_B64DECODE:
		(void)fprintf(stderr,
		    "usage: b64decode [-ciprs] [file ...]\n"
		    "       b64decode [-i] -o output_file [file]\n");
		break;
	}
	exit(1);
}