1 /*
2 +----------------------------------------------------------------------+
3 | PHP Version 7 |
4 +----------------------------------------------------------------------+
5 | Copyright (c) 1997-2018 The PHP Group |
6 +----------------------------------------------------------------------+
7 | This source file is subject to version 3.01 of the PHP license, |
8 | that is bundled with this package in the file LICENSE, and is |
9 | available through the world-wide-web at the following url: |
10 | http://www.php.net/license/3_01.txt |
11 | If you did not receive a copy of the PHP license and are unable to |
12 | obtain it through the world-wide-web, please send a note to |
13 | license@php.net so we can mail you a copy immediately. |
14 +----------------------------------------------------------------------+
15 | Authors: Derick Rethans <derick@php.net> |
16 +----------------------------------------------------------------------+
17 */
18
19 #include "php_filter.h"
20 #include "filter_private.h"
21 #include "zend_smart_str.h"
22
23 /* {{{ STRUCTS */
24 typedef unsigned long filter_map[256];
25 /* }}} */
26
27 /* {{{ HELPER FUNCTIONS */
php_filter_encode_html(zval * value,const unsigned char * chars)28 static void php_filter_encode_html(zval *value, const unsigned char *chars)
29 {
30 smart_str str = {0};
31 size_t len = Z_STRLEN_P(value);
32 unsigned char *s = (unsigned char *)Z_STRVAL_P(value);
33 unsigned char *e = s + len;
34
35 if (Z_STRLEN_P(value) == 0) {
36 return;
37 }
38
39 while (s < e) {
40 if (chars[*s]) {
41 smart_str_appendl(&str, "&#", 2);
42 smart_str_append_unsigned(&str, (zend_ulong)*s);
43 smart_str_appendc(&str, ';');
44 } else {
45 /* XXX: this needs to be optimized to work with blocks of 'safe' chars */
46 smart_str_appendc(&str, *s);
47 }
48 s++;
49 }
50
51 smart_str_0(&str);
52 zval_ptr_dtor(value);
53 ZVAL_NEW_STR(value, str.s);
54 }
55
56 static const unsigned char hexchars[] = "0123456789ABCDEF";
57
58 #define LOWALPHA "abcdefghijklmnopqrstuvwxyz"
59 #define HIALPHA "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
60 #define DIGIT "0123456789"
61
62 #define DEFAULT_URL_ENCODE LOWALPHA HIALPHA DIGIT "-._"
63
php_filter_encode_url(zval * value,const unsigned char * chars,const int char_len,int high,int low,int encode_nul)64 static void php_filter_encode_url(zval *value, const unsigned char* chars, const int char_len, int high, int low, int encode_nul)
65 {
66 unsigned char *p;
67 unsigned char tmp[256];
68 unsigned char *s = (unsigned char *)chars;
69 unsigned char *e = s + char_len;
70 zend_string *str;
71
72 memset(tmp, 1, sizeof(tmp)-1);
73
74 while (s < e) {
75 tmp[*s++] = '\0';
76 }
77 /* XXX: This is not needed since these chars in the allowed list never include the high/low/null value
78 if (encode_nul) {
79 tmp[0] = 1;
80 }
81 if (high) {
82 memset(tmp + 127, 1, sizeof(tmp) - 127);
83 }
84 if (low) {
85 memset(tmp, 1, 32);
86 }
87 */
88 str = zend_string_safe_alloc(Z_STRLEN_P(value), 3, 0, 0);
89 p = (unsigned char *) ZSTR_VAL(str);
90 s = (unsigned char *) Z_STRVAL_P(value);
91 e = s + Z_STRLEN_P(value);
92
93 while (s < e) {
94 if (tmp[*s]) {
95 *p++ = '%';
96 *p++ = hexchars[(unsigned char) *s >> 4];
97 *p++ = hexchars[(unsigned char) *s & 15];
98 } else {
99 *p++ = *s;
100 }
101 s++;
102 }
103 *p = '\0';
104 ZSTR_LEN(str) = p - (unsigned char *)ZSTR_VAL(str);
105 zval_ptr_dtor(value);
106 ZVAL_NEW_STR(value, str);
107 }
108
php_filter_strip(zval * value,zend_long flags)109 static void php_filter_strip(zval *value, zend_long flags)
110 {
111 unsigned char *str;
112 size_t i;
113 size_t c;
114 zend_string *buf;
115
116 /* Optimization for if no strip flags are set */
117 if (!(flags & (FILTER_FLAG_STRIP_LOW | FILTER_FLAG_STRIP_HIGH | FILTER_FLAG_STRIP_BACKTICK))) {
118 return;
119 }
120
121 str = (unsigned char *)Z_STRVAL_P(value);
122 buf = zend_string_alloc(Z_STRLEN_P(value), 0);
123 c = 0;
124 for (i = 0; i < Z_STRLEN_P(value); i++) {
125 if ((str[i] >= 127) && (flags & FILTER_FLAG_STRIP_HIGH)) {
126 } else if ((str[i] < 32) && (flags & FILTER_FLAG_STRIP_LOW)) {
127 } else if ((str[i] == '`') && (flags & FILTER_FLAG_STRIP_BACKTICK)) {
128 } else {
129 ZSTR_VAL(buf)[c] = str[i];
130 ++c;
131 }
132 }
133 /* update zval string data */
134 ZSTR_VAL(buf)[c] = '\0';
135 ZSTR_LEN(buf) = c;
136 zval_ptr_dtor(value);
137 ZVAL_NEW_STR(value, buf);
138 }
139 /* }}} */
140
141 /* {{{ FILTER MAP HELPERS */
filter_map_init(filter_map * map)142 static void filter_map_init(filter_map *map)
143 {
144 memset(map, 0, sizeof(filter_map));
145 }
146
filter_map_update(filter_map * map,int flag,const unsigned char * allowed_list)147 static void filter_map_update(filter_map *map, int flag, const unsigned char *allowed_list)
148 {
149 size_t l, i;
150
151 l = strlen((const char*)allowed_list);
152 for (i = 0; i < l; ++i) {
153 (*map)[allowed_list[i]] = flag;
154 }
155 }
156
filter_map_apply(zval * value,filter_map * map)157 static void filter_map_apply(zval *value, filter_map *map)
158 {
159 unsigned char *str;
160 size_t i, c;
161 zend_string *buf;
162
163 str = (unsigned char *)Z_STRVAL_P(value);
164 buf = zend_string_alloc(Z_STRLEN_P(value), 0);
165 c = 0;
166 for (i = 0; i < Z_STRLEN_P(value); i++) {
167 if ((*map)[str[i]]) {
168 ZSTR_VAL(buf)[c] = str[i];
169 ++c;
170 }
171 }
172 /* update zval string data */
173 ZSTR_VAL(buf)[c] = '\0';
174 ZSTR_LEN(buf) = c;
175 zval_ptr_dtor(value);
176 ZVAL_NEW_STR(value, buf);
177 }
178 /* }}} */
179
180 /* {{{ php_filter_string */
php_filter_string(PHP_INPUT_FILTER_PARAM_DECL)181 void php_filter_string(PHP_INPUT_FILTER_PARAM_DECL)
182 {
183 size_t new_len;
184 unsigned char enc[256] = {0};
185
186 if (!Z_REFCOUNTED_P(value)) {
187 ZVAL_STRINGL(value, Z_STRVAL_P(value), Z_STRLEN_P(value));
188 }
189
190 /* strip high/strip low ( see flags )*/
191 php_filter_strip(value, flags);
192
193 if (!(flags & FILTER_FLAG_NO_ENCODE_QUOTES)) {
194 enc['\''] = enc['"'] = 1;
195 }
196 if (flags & FILTER_FLAG_ENCODE_AMP) {
197 enc['&'] = 1;
198 }
199 if (flags & FILTER_FLAG_ENCODE_LOW) {
200 memset(enc, 1, 32);
201 }
202 if (flags & FILTER_FLAG_ENCODE_HIGH) {
203 memset(enc + 127, 1, sizeof(enc) - 127);
204 }
205
206 php_filter_encode_html(value, enc);
207
208 /* strip tags, implicitly also removes \0 chars */
209 new_len = php_strip_tags_ex(Z_STRVAL_P(value), Z_STRLEN_P(value), NULL, NULL, 0, 1);
210 Z_STRLEN_P(value) = new_len;
211
212 if (new_len == 0) {
213 zval_ptr_dtor(value);
214 if (flags & FILTER_FLAG_EMPTY_STRING_NULL) {
215 ZVAL_NULL(value);
216 } else {
217 ZVAL_EMPTY_STRING(value);
218 }
219 return;
220 }
221 }
222 /* }}} */
223
224 /* {{{ php_filter_encoded */
php_filter_encoded(PHP_INPUT_FILTER_PARAM_DECL)225 void php_filter_encoded(PHP_INPUT_FILTER_PARAM_DECL)
226 {
227 /* apply strip_high and strip_low filters */
228 php_filter_strip(value, flags);
229 /* urlencode */
230 php_filter_encode_url(value, (unsigned char *)DEFAULT_URL_ENCODE, sizeof(DEFAULT_URL_ENCODE)-1, flags & FILTER_FLAG_ENCODE_HIGH, flags & FILTER_FLAG_ENCODE_LOW, 1);
231 }
232 /* }}} */
233
234 /* {{{ php_filter_special_chars */
php_filter_special_chars(PHP_INPUT_FILTER_PARAM_DECL)235 void php_filter_special_chars(PHP_INPUT_FILTER_PARAM_DECL)
236 {
237 unsigned char enc[256] = {0};
238
239 php_filter_strip(value, flags);
240
241 /* encodes ' " < > & \0 to numerical entities */
242 enc['\''] = enc['"'] = enc['<'] = enc['>'] = enc['&'] = enc[0] = 1;
243
244 /* if strip low is not set, then we encode them as &#xx; */
245 memset(enc, 1, 32);
246
247 if (flags & FILTER_FLAG_ENCODE_HIGH) {
248 memset(enc + 127, 1, sizeof(enc) - 127);
249 }
250
251 php_filter_encode_html(value, enc);
252 }
253 /* }}} */
254
255 /* {{{ php_filter_full_special_chars */
php_filter_full_special_chars(PHP_INPUT_FILTER_PARAM_DECL)256 void php_filter_full_special_chars(PHP_INPUT_FILTER_PARAM_DECL)
257 {
258 zend_string *buf;
259 int quotes;
260
261 if (!(flags & FILTER_FLAG_NO_ENCODE_QUOTES)) {
262 quotes = ENT_QUOTES;
263 } else {
264 quotes = ENT_NOQUOTES;
265 }
266 buf = php_escape_html_entities_ex((unsigned char *) Z_STRVAL_P(value), Z_STRLEN_P(value), 1, quotes, SG(default_charset), 0);
267 zval_ptr_dtor(value);
268 ZVAL_STR(value, buf);
269 }
270 /* }}} */
271
272 /* {{{ php_filter_unsafe_raw */
php_filter_unsafe_raw(PHP_INPUT_FILTER_PARAM_DECL)273 void php_filter_unsafe_raw(PHP_INPUT_FILTER_PARAM_DECL)
274 {
275 /* Only if no flags are set (optimization) */
276 if (flags != 0 && Z_STRLEN_P(value) > 0) {
277 unsigned char enc[256] = {0};
278
279 php_filter_strip(value, flags);
280
281 if (flags & FILTER_FLAG_ENCODE_AMP) {
282 enc['&'] = 1;
283 }
284 if (flags & FILTER_FLAG_ENCODE_LOW) {
285 memset(enc, 1, 32);
286 }
287 if (flags & FILTER_FLAG_ENCODE_HIGH) {
288 memset(enc + 127, 1, sizeof(enc) - 127);
289 }
290
291 php_filter_encode_html(value, enc);
292 } else if (flags & FILTER_FLAG_EMPTY_STRING_NULL && Z_STRLEN_P(value) == 0) {
293 zval_ptr_dtor(value);
294 ZVAL_NULL(value);
295 }
296 }
297 /* }}} */
298
299 /* {{{ php_filter_email */
300 #define SAFE "$-_.+"
301 #define EXTRA "!*'(),"
302 #define NATIONAL "{}|\\^~[]`"
303 #define PUNCTUATION "<>#%\""
304 #define RESERVED ";/?:@&="
305
php_filter_email(PHP_INPUT_FILTER_PARAM_DECL)306 void php_filter_email(PHP_INPUT_FILTER_PARAM_DECL)
307 {
308 /* Check section 6 of rfc 822 http://www.faqs.org/rfcs/rfc822.html */
309 const unsigned char allowed_list[] = LOWALPHA HIALPHA DIGIT "!#$%&'*+-=?^_`{|}~@.[]";
310 filter_map map;
311
312 filter_map_init(&map);
313 filter_map_update(&map, 1, allowed_list);
314 filter_map_apply(value, &map);
315 }
316 /* }}} */
317
318 /* {{{ php_filter_url */
php_filter_url(PHP_INPUT_FILTER_PARAM_DECL)319 void php_filter_url(PHP_INPUT_FILTER_PARAM_DECL)
320 {
321 /* Strip all chars not part of section 5 of
322 * http://www.faqs.org/rfcs/rfc1738.html */
323 const unsigned char allowed_list[] = LOWALPHA HIALPHA DIGIT SAFE EXTRA NATIONAL PUNCTUATION RESERVED;
324 filter_map map;
325
326 filter_map_init(&map);
327 filter_map_update(&map, 1, allowed_list);
328 filter_map_apply(value, &map);
329 }
330 /* }}} */
331
332 /* {{{ php_filter_number_int */
php_filter_number_int(PHP_INPUT_FILTER_PARAM_DECL)333 void php_filter_number_int(PHP_INPUT_FILTER_PARAM_DECL)
334 {
335 /* strip everything [^0-9+-] */
336 const unsigned char allowed_list[] = "+-" DIGIT;
337 filter_map map;
338
339 filter_map_init(&map);
340 filter_map_update(&map, 1, allowed_list);
341 filter_map_apply(value, &map);
342 }
343 /* }}} */
344
345 /* {{{ php_filter_number_float */
php_filter_number_float(PHP_INPUT_FILTER_PARAM_DECL)346 void php_filter_number_float(PHP_INPUT_FILTER_PARAM_DECL)
347 {
348 /* strip everything [^0-9+-] */
349 const unsigned char allowed_list[] = "+-" DIGIT;
350 filter_map map;
351
352 filter_map_init(&map);
353 filter_map_update(&map, 1, allowed_list);
354
355 /* depending on flags, strip '.', 'e', ",", "'" */
356 if (flags & FILTER_FLAG_ALLOW_FRACTION) {
357 filter_map_update(&map, 2, (const unsigned char *) ".");
358 }
359 if (flags & FILTER_FLAG_ALLOW_THOUSAND) {
360 filter_map_update(&map, 3, (const unsigned char *) ",");
361 }
362 if (flags & FILTER_FLAG_ALLOW_SCIENTIFIC) {
363 filter_map_update(&map, 4, (const unsigned char *) "eE");
364 }
365 filter_map_apply(value, &map);
366 }
367 /* }}} */
368
369 /* {{{ php_filter_add_slashes */
php_filter_add_slashes(PHP_INPUT_FILTER_PARAM_DECL)370 void php_filter_add_slashes(PHP_INPUT_FILTER_PARAM_DECL)
371 {
372 /* This filter is used by both 'add_slashes' & 'magic_quotes' (legacy) */
373
374 zend_string *buf;
375
376 /* just call php_addslashes quotes */
377 buf = php_addslashes(Z_STR_P(value));
378
379 zval_ptr_dtor(value);
380 ZVAL_STR(value, buf);
381 }
382 /* }}} */
383
384 /*
385 * Local variables:
386 * tab-width: 4
387 * c-basic-offset: 4
388 * End:
389 * vim600: noet sw=4 ts=4 fdm=marker
390 * vim<600: noet sw=4 ts=4
391 */
392
