xref: /illumos-gate/usr/src/cmd/bnu/uudecode.c (revision 9b9d39d2a32ff806d2431dbcc50968ef1e6d46b2)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
23 /*	  All Rights Reserved  	*/
24 
25 /*	Copyright 2004 Sun Microsystems, Inc.  All rights reserved. */
26 /*	Use is subject to license terms. */
27 
28 /*
29  * uudecode [-o outfile | -p] [input]
30  *
31  * create the specified file, decoding as you go.
32  * used with uuencode.
33  */
34 #include <unistd.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <pwd.h>
38 #include <string.h>
39 #include <strings.h>
40 #include <sys/types.h>
41 #include <sys/stat.h>
42 #include <locale.h>
43 #include <nl_types.h>
44 #include <langinfo.h>
45 #include <iconv.h>
46 #include <limits.h>
47 #include <errno.h>
48 #include <ctype.h>
49 #include <signal.h>
50 #include <stdarg.h>
51 
52 #define	BUFSIZE	90	/* must be a multiple of 3 */
53 
54 #define	TABLE_SIZE	0x40
55 
56 #define	isvalid(octet)	(octet <= 0x40)
57 
58 /*
59  * base64 decoding table
60  */
61 /* BEGIN CSTYLED */
62 static char base64tab[] = {
63 	'\377', '\377', '\377', '\377', '\377', '\377', '\377', '\377',
64 	'\377', '\377', '\377', '\377', '\377', '\377', '\377', '\377',
65 	'\377', '\377', '\377', '\377', '\377', '\377', '\377', '\377',
66 	'\377', '\377', '\377', '\377', '\377', '\377', '\377', '\377',
67 	'\377', '\377', '\377', '\377', '\377', '\377', '\377', '\377',
68 	'\377', '\377', '\377',     62, '\377', '\377', '\377',     63,
69 	    52,     53,     54,     55,     56,     57,     58,     59,
70 	    60,     61, '\377', '\377', '\377', '\377', '\377', '\377',
71 	'\377',      0,      1,      2,      3,      4,      5,      6,
72 	     7,      8,      9,     10,     11,     12,     13,     14,
73 	    15,     16,     17,     18,     19,     20,     21,     22,
74 	    23,     24,     25, '\377', '\377', '\377', '\377', '\377',
75 	'\377',     26,     27,     28,     29,     30,     31,     32,
76 	    33,     34,     35,     36,     37,     38,     39,     40,
77 	    41,     42,     43,     44,     45,     46,     47,     48,
78 	    49,     50,     51, '\377', '\377', '\377', '\377', '\377'
79 };
80 /* END CSTYLED */
81 
82 static char	decode_table[UCHAR_MAX + 1];
83 
84 /* DEC is the basic 1 character decoding function (historical algorithm) */
85 #define	DEC(c)	decode_table[c]
86 
87 /* true if the character is in the base64 encoding table */
88 #define	validbase64(c) (('A' <= (c) && (c) <= 'Z') || \
89 		('a' <= (c) && (c) <= 'z') || \
90 		('0' <= (c) && (c) <= '9') || \
91 		(c) == '+' || (c) == '/')
92 
93 static void	decode(FILE *, FILE *, int);
94 static int	outdec(unsigned char *, unsigned char *, int);
95 static int	outdec64(unsigned char *, unsigned char *, int);
96 
97 /* from usr/src/cmd/chmod/common.c */
98 
99 void errmsg(int severity, int code, char *format, ...);
100 
101 extern mode_t newmode(char *ms, mode_t new_mode, mode_t umsk,
102     char *file, char *path);
103 
104 static char	*prog;
105 static char	outfile[PATH_MAX];
106 static int	mode_err = 0;	/* mode conversion error flag */
107 
108 int
109 main(int argc, char **argv)
110 {
111 	FILE *in, *out;
112 	int pipeout = 0;
113 	int oflag = 0;
114 	int i;
115 	mode_t mode, p_umask;
116 	char dest[PATH_MAX];
117 	char modebits[1024];
118 	char buf[LINE_MAX];
119 	int	c, errflag = 0;
120 	struct stat sbuf;
121 	int base64flag = 0;
122 
123 	prog = argv[0];
124 	(void) signal(SIGPIPE, SIG_DFL);
125 	bzero(dest, sizeof (dest));
126 	outfile[0] = '\0';
127 
128 	/* Set locale environment variables local definitions */
129 	(void) setlocale(LC_ALL, "");
130 #if !defined(TEXT_DOMAIN)	/* Should be defined by cc -D */
131 #define	TEXT_DOMAIN "SYS_TEST"	/* Use this only if it wasn't */
132 #endif
133 	(void) textdomain(TEXT_DOMAIN);
134 	p_umask = umask((mode_t)0);
135 
136 	while ((c = getopt(argc, argv, "o:p")) != EOF) {
137 		switch (c) {
138 		case 'o':
139 			oflag++;
140 			(void) strncpy(outfile, optarg, sizeof (outfile));
141 			break;
142 		case 'p':
143 			pipeout++;
144 			break;
145 		default:
146 		case '?':
147 			errflag++;
148 			break;
149 		}
150 	}
151 	argc -= optind;
152 	argv = &argv[optind];
153 
154 	/* optional input arg */
155 	if (argc > 0) {
156 		if ((in = fopen(*argv, "r")) == NULL) {
157 			perror(*argv);
158 			exit(1);
159 		}
160 		argv++; argc--;
161 	} else {
162 		in = stdin;
163 		errno = 0;
164 		if (fstat(fileno(in), &sbuf) < 0) {
165 			perror("stdin");
166 			exit(1);
167 		}
168 	}
169 
170 	if ((argc > 0) || errflag || (oflag && pipeout)) {
171 		(void) fprintf(stderr,
172 		    gettext("Usage: %s [-o outfile | -p] [infile]\n"), prog);
173 		exit(2);
174 	}
175 
176 	/* search for header line */
177 	for (;;) {
178 		if (fgets(buf, sizeof (buf), in) == NULL) {
179 			/* suppress message if we printed a mode error */
180 			if (mode_err == 0)
181 				(void) fprintf(stderr,
182 				    gettext("No begin line\n"));
183 			exit(3);
184 		}
185 		/*
186 		 * the check for begin-base64 obviously needs to come
187 		 * first, since both algorithms' begin strings start
188 		 * with 'begin'.  Also verify that there is a valid
189 		 * octal or symbolic file mode.
190 		 */
191 		if (strncmp(buf, "begin-base64", 12) == 0) {
192 			base64flag = 1;
193 			mode_err = 0;
194 			if ((sscanf(buf + 13, "%1023s %1023s",
195 			    modebits, dest) == 2) &&
196 			    ((sscanf(modebits, "%lo", &mode) == 1) ||
197 				((mode = newmode(modebits, 0, p_umask,
198 				    "", "")) != 0) && mode_err == 0))
199 				break;
200 		} else if (strncmp(buf, "begin", 5) == 0) {
201 			base64flag = 0;
202 			mode_err = 0;
203 			if ((sscanf(buf + 6, "%1023s %1023s",
204 			    modebits, dest) == 2) &&
205 			    ((sscanf(modebits, "%lo", &mode) == 1) ||
206 				((mode = newmode(modebits, 0, p_umask,
207 				    "", "")) != 0) && mode_err == 0))
208 				break;
209 		}
210 	}
211 
212 	/*
213 	 * Now that we know the type of encoding used, we can
214 	 * initialize the decode table.
215 	 */
216 	if (base64flag == 0) {
217 		(void) memset(decode_table, 0xFF, sizeof (decode_table));
218 		for (i = 0; i <= TABLE_SIZE; i++)
219 			decode_table[(unsigned char)i + 0x20] =
220 			    (unsigned char)i & 0x3F;
221 	} else
222 		(void) memcpy(decode_table, base64tab, sizeof (base64tab));
223 
224 	/*
225 	 * Filename specified on the command line with -o
226 	 * overrides filename in the encoded file.
227 	 */
228 	if (outfile[0] != '\0')
229 		(void) strncpy(dest, outfile, sizeof (dest));
230 
231 	if (pipeout ||
232 	    (dest[0] == '-' && dest[1] == '\0' && outfile[0] == '\0')) {
233 		out = stdout;
234 		bzero(outfile, sizeof (outfile));
235 		bzero(dest, sizeof (dest));
236 	} else {
237 		/* handle ~user/file format */
238 		if (dest[0] == '~') {
239 			char *sl;
240 			struct passwd *user;
241 			char dnbuf[100];
242 
243 			sl = strchr(dest, '/');
244 			if (sl == NULL) {
245 				(void) fprintf(stderr,
246 				    gettext("Illegal ~user\n"));
247 				exit(3);
248 			}
249 			*sl++ = 0;
250 			user = getpwnam(dest+1);
251 			if (user == NULL) {
252 				(void) fprintf(stderr,
253 				    gettext("No such user as %s\n"), dest);
254 				exit(4);
255 			}
256 			(void) strncpy(dnbuf, user->pw_dir, sizeof (dnbuf));
257 			(void) strlcat(dnbuf, "/", sizeof (dnbuf));
258 			(void) strlcat(dnbuf, sl, sizeof (dnbuf));
259 			(void) strncpy(dest, dnbuf, sizeof (dest));
260 		}
261 	}
262 	/* if not using stdout, create file */
263 	if (dest[0] != '\0') {
264 		if ((out = fopen(dest, "w")) == NULL) {
265 			perror(dest);
266 			exit(4);
267 		}
268 		(void) chmod(dest, mode & 0777);
269 	}
270 
271 	decode(in, out, base64flag);
272 
273 	if (fclose(out) == EOF) {
274 		perror(prog);
275 		exit(6);
276 	}
277 
278 	return (0);
279 }
280 
281 /*
282  * copy from in to out, decoding as you go along.
283  */
284 
285 static void
286 decode(FILE *in, FILE *out, int base64)
287 {
288 	char	inbuf[120], *ibp, *iptr;
289 	unsigned char 	outbuf[BUFSIZE], *obp, *optr;
290 	int	n, octets, warned, endseen, numbase64chars;
291 	unsigned char chr[4], curchr, ch;
292 	longlong_t line;
293 
294 	if (! base64) {	/* use historical algorithm */
295 		warned = 0;
296 		for (line = 1; ; line++) {
297 			/* for each input line */
298 			if (fgets(inbuf, sizeof (inbuf), in) == NULL) {
299 				(void) fprintf(stderr,
300 				    gettext("No end line\n"));
301 				exit(5);
302 			}
303 
304 			/* Is line == 'end\n'? */
305 			if (strcmp(inbuf, "end\n") == 0) {
306 				break;
307 			}
308 
309 			n = DEC(inbuf[0]);
310 
311 			if (n < 0)
312 				continue;
313 
314 			/*
315 			 * Decode data lines.
316 			 *
317 			 * Note that uuencode/uudecode uses only the portable
318 			 * character set for encoded data and the portable
319 			 * character set characters must be represented in
320 			 * a single byte.  We use this knowledge to reuse
321 			 * buffer space while decoding.
322 			 */
323 			octets = n;
324 			obp = (unsigned char *) &inbuf[0];
325 			ibp = &inbuf[1];
326 			while (octets > 0) {
327 				if ((ch = outdec((unsigned char *)obp,
328 				    (unsigned char *)ibp, octets))
329 				    != 0x20) {
330 					/* invalid characters where detected */
331 					if (!warned) {
332 						warned = 1;
333 						(void) fprintf(stderr,
334 						    gettext("Invalid character"
335 							" (0x%x) on line"
336 							" %lld\n"), ch, line);
337 					}
338 					break;
339 				}
340 				ibp += 4;
341 				obp += 3;
342 				octets -= 3;
343 			}
344 			/*
345 			 * Only write out uncorrupted lines
346 			 */
347 			if (octets <= 0) {
348 				(void) fwrite(inbuf, n, 1, out);
349 			}
350 		}
351 	} else {	/* use base64 algorithm */
352 		endseen = numbase64chars = 0;
353 		optr = outbuf;
354 		while ((fgets(inbuf, sizeof (inbuf), in)) != NULL) {
355 			/* process an input line */
356 			iptr = inbuf;
357 			while ((curchr = *(iptr++)) != '\0') {
358 				/* decode chars */
359 				if (curchr == '=') /* if end */
360 					endseen++;
361 
362 				if (validbase64(curchr))
363 					chr[numbase64chars++] = curchr;
364 				/*
365 				 * if we've gathered 4 base64 octets
366 				 * we need to decode and output them
367 				 */
368 				if (numbase64chars == 4) {
369 					/*LINTED*/
370 					if (optr - outbuf > BUFSIZE - 3) {
371 						(void) fwrite(outbuf,
372 						    /*LINTED*/
373 						    (size_t)(optr - outbuf),
374 						    1, out);
375 						if (ferror(out)) {
376 							perror(prog);
377 							exit(6);
378 						}
379 						optr = outbuf;
380 					}
381 					octets = outdec64(optr, chr, 4);
382 					optr += octets;
383 					numbase64chars = 0;
384 				}
385 			}
386 			/*
387 			 * handle any remaining base64 octets at end
388 			 */
389 			if (endseen && numbase64chars > 0) {
390 				octets = outdec64(optr, chr, numbase64chars);
391 				optr += octets;
392 				numbase64chars = 0;
393 			}
394 		}
395 		/*
396 		 * if we have generated any additional output
397 		 * in the buffer, write it out
398 		 */
399 		if (optr != outbuf) {
400 			/*LINTED*/
401 			(void) fwrite(outbuf, (size_t)(optr - outbuf),
402 			    1, out);
403 			if (ferror(out)) {
404 				perror(prog);
405 				exit(6);
406 			}
407 		}
408 
409 		if (endseen == 0) {
410 			(void) fprintf(stderr, gettext("No end line\n"));
411 			exit(5);
412 		}
413 	}
414 }
415 
416 /*
417  * historical algorithm
418  *
419  * output a group of 3 bytes (4 input characters).
420  * the input chars are pointed to by p, they are to
421  * be output to file f.  n is used to tell us not to
422  * output all of them at the end of the file.
423  */
424 
425 static int
426 outdec(unsigned char *out, unsigned char *in, int n)
427 {
428 	unsigned char	b0 = DEC(*(in++));
429 	unsigned char	b1 = DEC(*(in++));
430 	unsigned char	b2 = DEC(*(in++));
431 	unsigned char	b3 = DEC(*in);
432 
433 	if (!isvalid(b0)) {
434 		return (*(in-3));
435 	}
436 	if (!isvalid(b1)) {
437 		return (*(in-2));
438 	}
439 
440 	*(out++) = (b0 << 2) | (b1 >> 4);
441 
442 	if (n >= 2) {
443 		if (!isvalid(b2)) {
444 			return (*(in - 1));
445 		}
446 
447 		*(out++) = (b1 << 4) | (b2 >> 2);
448 
449 		if (n >= 3) {
450 			if (!isvalid(b3)) {
451 				return (*in);
452 			}
453 			*out = (b2 << 6) | b3;
454 		}
455 	}
456 	return (0x20); /* a know good value */
457 }
458 
459 /*
460  * base64 algorithm
461  *
462  * Takes a pointer to the current position in the output buffer,
463  * a pointer to the (up to) 4 byte base64 input buffer and a
464  * count of the number of valid input bytes.
465  *
466  * Return the number of bytes placed in the output buffer
467  */
468 static int
469 outdec64(unsigned char *out, unsigned char *chr, int num)
470 {
471 
472 	unsigned char char1, char2, char3, char4;
473 	unsigned char *outptr = out;
474 	int rc = 0;
475 
476 	switch (num) {
477 	case 0:
478 	case 1: 	/* these are impossible */
479 	default:
480 		break;
481 	case 2:		/* 2 base64 bytes == 1 decoded byte */
482 		char1 = base64tab[chr[0]] & 0xFF;
483 		char2 = base64tab[chr[1]] & 0xFF;
484 		*(outptr++) = ((char1 << 2) & 0xFC) |
485 		    ((char2 >> 4) & 0x03);
486 		rc = 1;
487 		break;
488 	case 3:		/* 3 base64 bytes == 2 decoded bytes */
489 		char1 = base64tab[chr[0]] & 0xFF;
490 		char2 = base64tab[chr[1]] & 0xFF;
491 		char3 = base64tab[chr[2]] & 0xFF;
492 		*(outptr++) = ((char1 << 2) & 0xFC) |
493 		    ((char2 >> 4) & 0x03);
494 		*(outptr++) = ((char2 << 4) & 0xF0) |
495 		    ((char3 >> 2) & 0x0F);
496 		rc = 2;
497 		break;
498 	case 4:		/* 4 base64 bytes == 3 decoded bytes */
499 		char1 = base64tab[chr[0]] & 0xFF;
500 		char2 = base64tab[chr[1]] & 0xFF;
501 		char3 = base64tab[chr[2]] & 0xFF;
502 		char4 = base64tab[chr[3]] & 0xFF;
503 		*(outptr++) = ((char1 << 2) & 0xFC) |
504 		    ((char2 >> 4) & 0x03);
505 		*(outptr++) = ((char2 << 4) & 0xF0) |
506 		    ((char3 >> 2) & 0x0F);
507 		*(outptr++) = ((char3 << 6) & 0xC0) |
508 		    (char4 & 0x3F);
509 		rc = 3;
510 		break;
511 	}
512 	return (rc);
513 }
514 
515 /*
516  * error message routine called by newmode.
517  *
518  * The severity and code are ignored here.  If this routine gets
519  * called, we set a global flag (which can be tested after return
520  * from here) which tells us whether or not a valid mode has been
521  * parsed or if we printed an error message.
522  */
523 
524 /*ARGSUSED*/
525 void
526 errmsg(int severity, int code, char *format, ...)
527 {
528 	va_list ap;
529 
530 	va_start(ap, format);
531 
532 	(void) fprintf(stderr, "uudecode: ");
533 	(void) fprintf(stderr, format, ap);
534 
535 	va_end(ap);
536 
537 	mode_err = 1;
538 }
539