xref: /PHP-7.0/ext/fileinfo/libmagic/funcs.c (revision 4b0b1cec)
1 /*
2  * Copyright (c) Christos Zoulas 2003.
3  * All Rights Reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice immediately at the beginning of the file, without modification,
10  *    this list of conditions, and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
19  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 #include "file.h"
28 
29 #ifndef	lint
30 FILE_RCSID("@(#)$File: funcs.c,v 1.79 2014/12/16 20:52:49 christos Exp $")
31 #endif	/* lint */
32 
33 #include "magic.h"
34 #include <stdarg.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <ctype.h>
38 #if defined(HAVE_WCHAR_H)
39 #include <wchar.h>
40 #endif
41 #if defined(HAVE_WCTYPE_H)
42 #include <wctype.h>
43 #endif
44 #if defined(HAVE_LOCALE_H)
45 #include <locale.h>
46 #endif
47 
48 #ifndef SIZE_MAX
49 #define SIZE_MAX	((size_t)~0)
50 #endif
51 
52 #include "php.h"
53 #include "main/php_network.h"
54 
55 #ifndef PREG_OFFSET_CAPTURE
56 # define PREG_OFFSET_CAPTURE                 (1<<8)
57 #endif
58 
59 extern public void convert_libmagic_pattern(zval *pattern, char *val, int len, int options);
60 
61 protected int
file_printf(struct magic_set * ms,const char * fmt,...)62 file_printf(struct magic_set *ms, const char *fmt, ...)
63 {
64 	va_list ap;
65 	int len;
66 	char *buf = NULL, *newstr;
67 
68 	va_start(ap, fmt);
69 	len = vspprintf(&buf, 0, fmt, ap);
70 	va_end(ap);
71 
72 	if (ms->o.buf != NULL) {
73 		len = spprintf(&newstr, 0, "%s%s", ms->o.buf, (buf ? buf : ""));
74 		if (buf) {
75 			efree(buf);
76 		}
77 		efree(ms->o.buf);
78 		ms->o.buf = newstr;
79 	} else {
80 		ms->o.buf = buf;
81 	}
82 	return 0;
83 }
84 
85 /*
86  * error - print best error message possible
87  */
88 /*VARARGS*/
89 private void
file_error_core(struct magic_set * ms,int error,const char * f,va_list va,size_t lineno)90 file_error_core(struct magic_set *ms, int error, const char *f, va_list va,
91     size_t lineno)
92 {
93 	char *buf = NULL;
94 
95 	/* Only the first error is ok */
96 	if (ms->event_flags & EVENT_HAD_ERR)
97 		return;
98 	if (lineno != 0) {
99 		efree(ms->o.buf);
100 		ms->o.buf = NULL;
101 		file_printf(ms, "line %" SIZE_T_FORMAT "u: ", lineno);
102 	}
103 
104 	vspprintf(&buf, 0, f, va);
105 	va_end(va);
106 
107 	if (error > 0) {
108 		file_printf(ms, "%s (%s)", (*buf ? buf : ""), strerror(error));
109 	} else if (*buf) {
110 		file_printf(ms, "%s", buf);
111 	}
112 
113 	if (buf) {
114 		efree(buf);
115 	}
116 
117 	ms->event_flags |= EVENT_HAD_ERR;
118 	ms->error = error;
119 }
120 
121 /*VARARGS*/
122 protected void
file_error(struct magic_set * ms,int error,const char * f,...)123 file_error(struct magic_set *ms, int error, const char *f, ...)
124 {
125 	va_list va;
126 	va_start(va, f);
127 	file_error_core(ms, error, f, va, 0);
128 	va_end(va);
129 }
130 
131 /*
132  * Print an error with magic line number.
133  */
134 /*VARARGS*/
135 protected void
file_magerror(struct magic_set * ms,const char * f,...)136 file_magerror(struct magic_set *ms, const char *f, ...)
137 {
138 	va_list va;
139 	va_start(va, f);
140 	file_error_core(ms, 0, f, va, ms->line);
141 	va_end(va);
142 }
143 
144 protected void
file_oomem(struct magic_set * ms,size_t len)145 file_oomem(struct magic_set *ms, size_t len)
146 {
147 	file_error(ms, errno, "cannot allocate %" SIZE_T_FORMAT "u bytes",
148 	    len);
149 }
150 
151 protected void
file_badseek(struct magic_set * ms)152 file_badseek(struct magic_set *ms)
153 {
154 	file_error(ms, errno, "error seeking");
155 }
156 
157 protected void
file_badread(struct magic_set * ms)158 file_badread(struct magic_set *ms)
159 {
160 	file_error(ms, errno, "error reading");
161 }
162 
163 protected int
file_buffer(struct magic_set * ms,php_stream * stream,const char * inname,const void * buf,size_t nb)164 file_buffer(struct magic_set *ms, php_stream *stream, const char *inname, const void *buf,
165     size_t nb)
166 {
167 	int m = 0, rv = 0, looks_text = 0;
168 	int mime = ms->flags & MAGIC_MIME;
169 	const unsigned char *ubuf = CAST(const unsigned char *, buf);
170 	unichar *u8buf = NULL;
171 	size_t ulen;
172 	const char *code = NULL;
173 	const char *code_mime = "binary";
174 	const char *type = "application/octet-stream";
175 	const char *def = "data";
176 	const char *ftype = NULL;
177 
178 	if (nb == 0) {
179 		def = "empty";
180 		type = "application/x-empty";
181 		goto simple;
182 	} else if (nb == 1) {
183 		def = "very short file (no magic)";
184 		goto simple;
185 	}
186 
187 	if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) {
188 		looks_text = file_encoding(ms, ubuf, nb, &u8buf, &ulen,
189 		    &code, &code_mime, &ftype);
190 	}
191 
192 #ifdef __EMX__
193 	if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) {
194 		switch (file_os2_apptype(ms, inname, buf, nb)) {
195 		case -1:
196 			return -1;
197 		case 0:
198 			break;
199 		default:
200 			return 1;
201 		}
202 	}
203 #endif
204 
205 #if PHP_FILEINFO_UNCOMPRESS
206 	if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0)
207 		if ((m = file_zmagic(ms, stream, inname, ubuf, nb)) != 0) {
208 			if ((ms->flags & MAGIC_DEBUG) != 0)
209 				(void)fprintf(stderr, "zmagic %d\n", m);
210 			goto done_encoding;
211 		}
212 #endif
213 	/* Check if we have a tar file */
214 	if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0)
215 		if ((m = file_is_tar(ms, ubuf, nb)) != 0) {
216 			if ((ms->flags & MAGIC_DEBUG) != 0)
217 				(void)fprintf(stderr, "tar %d\n", m);
218 			goto done;
219 		}
220 
221 	/* Check if we have a CDF file */
222 	if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0) {
223 		php_socket_t fd;
224 			if (stream && SUCCESS == php_stream_cast(stream, PHP_STREAM_AS_FD, (void **)&fd, 0)) {
225 			if ((m = file_trycdf(ms, fd, ubuf, nb)) != 0) {
226 				if ((ms->flags & MAGIC_DEBUG) != 0)
227 					(void)fprintf(stderr, "cdf %d\n", m);
228 				goto done;
229 			}
230 		}
231 	}
232 
233 	/* try soft magic tests */
234 	if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0)
235 		if ((m = file_softmagic(ms, ubuf, nb, 0, NULL, BINTEST,
236 		    looks_text)) != 0) {
237 			if ((ms->flags & MAGIC_DEBUG) != 0)
238 				(void)fprintf(stderr, "softmagic %d\n", m);
239 #ifdef BUILTIN_ELF
240 			if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && m == 1 &&
241 			    nb > 5 && fd != -1) {
242 				/*
243 				 * We matched something in the file, so this
244 				 * *might* be an ELF file, and the file is at
245 				 * least 5 bytes long, so if it's an ELF file
246 				 * it has at least one byte past the ELF magic
247 				 * number - try extracting information from the
248 				 * ELF headers that cannot easily * be
249 				 * extracted with rules in the magic file.
250 				 */
251 				if ((m = file_tryelf(ms, fd, ubuf, nb)) != 0)
252 					if ((ms->flags & MAGIC_DEBUG) != 0)
253 						(void)fprintf(stderr,
254 						    "elf %d\n", m);
255 			}
256 #endif
257 			goto done;
258 		}
259 
260 	/* try text properties */
261 	if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) {
262 
263 		if ((m = file_ascmagic(ms, ubuf, nb, looks_text)) != 0) {
264 			if ((ms->flags & MAGIC_DEBUG) != 0)
265 				(void)fprintf(stderr, "ascmagic %d\n", m);
266 			goto done;
267 		}
268 	}
269 
270 simple:
271 	/* give up */
272 	m = 1;
273 	if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
274 	    file_printf(ms, "%s", mime ? type : def) == -1) {
275 	    rv = -1;
276 	}
277  done:
278 	if ((ms->flags & MAGIC_MIME_ENCODING) != 0) {
279 		if (ms->flags & MAGIC_MIME_TYPE)
280 			if (file_printf(ms, "; charset=") == -1)
281 				rv = -1;
282 		if (file_printf(ms, "%s", code_mime) == -1)
283 			rv = -1;
284 	}
285 #if PHP_FILEINFO_UNCOMPRESS
286  done_encoding:
287 #endif
288 	free(u8buf);
289 	if (rv)
290 		return rv;
291 
292 	return m;
293 }
294 
295 protected int
file_reset(struct magic_set * ms)296 file_reset(struct magic_set *ms)
297 {
298 	if (ms->mlist[0] == NULL) {
299 		file_error(ms, 0, "no magic files loaded");
300 		return -1;
301 	}
302 	if (ms->o.buf) {
303 		efree(ms->o.buf);
304 		ms->o.buf = NULL;
305 	}
306 	if (ms->o.pbuf) {
307 		efree(ms->o.pbuf);
308 		ms->o.pbuf = NULL;
309 	}
310 	ms->event_flags &= ~EVENT_HAD_ERR;
311 	ms->error = -1;
312 	return 0;
313 }
314 
315 #define OCTALIFY(n, o)	\
316 	/*LINTED*/ \
317 	(void)(*(n)++ = '\\', \
318 	*(n)++ = (((uint32_t)*(o) >> 6) & 3) + '0', \
319 	*(n)++ = (((uint32_t)*(o) >> 3) & 7) + '0', \
320 	*(n)++ = (((uint32_t)*(o) >> 0) & 7) + '0', \
321 	(o)++)
322 
323 protected const char *
file_getbuffer(struct magic_set * ms)324 file_getbuffer(struct magic_set *ms)
325 {
326 	char *op, *np;
327 	size_t psize, len;
328 
329 	if (ms->event_flags & EVENT_HAD_ERR)
330 		return NULL;
331 
332 	if (ms->flags & MAGIC_RAW)
333 		return ms->o.buf;
334 
335 	if (ms->o.buf == NULL)
336 		return NULL;
337 
338 	/* * 4 is for octal representation, + 1 is for NUL */
339 	len = strlen(ms->o.buf);
340 	if (len > (SIZE_MAX - 1) / 4) {
341 		file_oomem(ms, len);
342 		return NULL;
343 	}
344 	psize = len * 4 + 1;
345 	if ((ms->o.pbuf = CAST(char *, erealloc(ms->o.pbuf, psize))) == NULL) {
346 		file_oomem(ms, psize);
347 		return NULL;
348 	}
349 
350 #if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH)
351 	{
352 		mbstate_t state;
353 		wchar_t nextchar;
354 		int mb_conv = 1;
355 		size_t bytesconsumed;
356 		char *eop;
357 		(void)memset(&state, 0, sizeof(mbstate_t));
358 
359 		np = ms->o.pbuf;
360 		op = ms->o.buf;
361 		eop = op + len;
362 
363 		while (op < eop) {
364 			bytesconsumed = mbrtowc(&nextchar, op,
365 			    (size_t)(eop - op), &state);
366 			if (bytesconsumed == (size_t)(-1) ||
367 			    bytesconsumed == (size_t)(-2)) {
368 				mb_conv = 0;
369 				break;
370 			}
371 
372 			if (iswprint(nextchar)) {
373 				(void)memcpy(np, op, bytesconsumed);
374 				op += bytesconsumed;
375 				np += bytesconsumed;
376 			} else {
377 				while (bytesconsumed-- > 0)
378 					OCTALIFY(np, op);
379 			}
380 		}
381 		*np = '\0';
382 
383 		/* Parsing succeeded as a multi-byte sequence */
384 		if (mb_conv != 0)
385 			return ms->o.pbuf;
386 	}
387 #endif
388 
389 	for (np = ms->o.pbuf, op = ms->o.buf; *op;) {
390 		if (isprint((unsigned char)*op)) {
391 			*np++ = *op++;
392 		} else {
393 			OCTALIFY(np, op);
394 		}
395 	}
396 	*np = '\0';
397 	return ms->o.pbuf;
398 }
399 
400 protected int
file_check_mem(struct magic_set * ms,unsigned int level)401 file_check_mem(struct magic_set *ms, unsigned int level)
402 {
403 	size_t len;
404 
405 	if (level >= ms->c.len) {
406 		len = (ms->c.len = 20 + level) * sizeof(*ms->c.li);
407 		ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ?
408 		    emalloc(len) :
409 		    erealloc(ms->c.li, len));
410 		if (ms->c.li == NULL) {
411 			file_oomem(ms, len);
412 			return -1;
413 		}
414 	}
415 	ms->c.li[level].got_match = 0;
416 #ifdef ENABLE_CONDITIONALS
417 	ms->c.li[level].last_match = 0;
418 	ms->c.li[level].last_cond = COND_NONE;
419 #endif /* ENABLE_CONDITIONALS */
420 	return 0;
421 }
422 
423 protected size_t
file_printedlen(const struct magic_set * ms)424 file_printedlen(const struct magic_set *ms)
425 {
426 	return ms->o.buf == NULL ? 0 : strlen(ms->o.buf);
427 }
428 
429 protected int
file_replace(struct magic_set * ms,const char * pat,const char * rep)430 file_replace(struct magic_set *ms, const char *pat, const char *rep)
431 {
432 	zval patt;
433 	int opts = 0;
434 	pcre_cache_entry *pce;
435 	zend_string *res;
436 	zval repl;
437 	int  rep_cnt = 0;
438 
439 	(void)setlocale(LC_CTYPE, "C");
440 
441 	opts |= PCRE_MULTILINE;
442 	convert_libmagic_pattern(&patt, (char*)pat, strlen(pat), opts);
443 	if ((pce = pcre_get_compiled_regex_cache(Z_STR(patt))) == NULL) {
444 		zval_ptr_dtor(&patt);
445 		rep_cnt = -1;
446 		goto out;
447 	}
448 	zval_ptr_dtor(&patt);
449 
450 	ZVAL_STRING(&repl, rep);
451 	res = php_pcre_replace_impl(pce, NULL, ms->o.buf, strlen(ms->o.buf), &repl, 0, -1, &rep_cnt);
452 
453 	zval_ptr_dtor(&repl);
454 	if (NULL == res) {
455 		rep_cnt = -1;
456 		goto out;
457 	}
458 
459 	strncpy(ms->o.buf, ZSTR_VAL(res), ZSTR_LEN(res));
460 	ms->o.buf[ZSTR_LEN(res)] = '\0';
461 
462 	zend_string_release(res);
463 
464 out:
465 	(void)setlocale(LC_CTYPE, "");
466 	return rep_cnt;
467 }
468 
469 protected file_pushbuf_t *
file_push_buffer(struct magic_set * ms)470 file_push_buffer(struct magic_set *ms)
471 {
472 	file_pushbuf_t *pb;
473 
474 	if (ms->event_flags & EVENT_HAD_ERR)
475 		return NULL;
476 
477 	if ((pb = (CAST(file_pushbuf_t *, emalloc(sizeof(*pb))))) == NULL)
478 		return NULL;
479 
480 	pb->buf = ms->o.buf;
481 	pb->offset = ms->offset;
482 
483 	ms->o.buf = NULL;
484 	ms->offset = 0;
485 
486 	return pb;
487 }
488 
489 protected char *
file_pop_buffer(struct magic_set * ms,file_pushbuf_t * pb)490 file_pop_buffer(struct magic_set *ms, file_pushbuf_t *pb)
491 {
492 	char *rbuf;
493 
494 	if (ms->event_flags & EVENT_HAD_ERR) {
495 		efree(pb->buf);
496 		efree(pb);
497 		return NULL;
498 	}
499 
500 	rbuf = ms->o.buf;
501 
502 	ms->o.buf = pb->buf;
503 	ms->offset = pb->offset;
504 
505 	efree(pb);
506 	return rbuf;
507 }
508 
509 /*
510  * convert string to ascii printable format.
511  */
512 protected char *
file_printable(char * buf,size_t bufsiz,const char * str)513 file_printable(char *buf, size_t bufsiz, const char *str)
514 {
515 	char *ptr, *eptr;
516 	const unsigned char *s = (const unsigned char *)str;
517 
518 	for (ptr = buf, eptr = ptr + bufsiz - 1; ptr < eptr && *s; s++) {
519 		if (isprint(*s)) {
520 			*ptr++ = *s;
521 			continue;
522 		}
523 		if (ptr >= eptr - 3)
524 			break;
525 		*ptr++ = '\\';
526 		*ptr++ = ((*s >> 6) & 7) + '0';
527 		*ptr++ = ((*s >> 3) & 7) + '0';
528 		*ptr++ = ((*s >> 0) & 7) + '0';
529 	}
530 	*ptr = '\0';
531 	return buf;
532 }
533 
534