1 /*************************************************
2 *      Perl-Compatible Regular Expressions       *
3 *************************************************/
4 
5 /* PCRE is a library of functions to support regular expressions whose syntax
6 and semantics are as close as possible to those of the Perl 5 language.
7 
8                        Written by Philip Hazel
9      Original API code Copyright (c) 1997-2012 University of Cambridge
10           New API code Copyright (c) 2016-2020 University of Cambridge
11 
12 -----------------------------------------------------------------------------
13 Redistribution and use in source and binary forms, with or without
14 modification, are permitted provided that the following conditions are met:
15 
16     * Redistributions of source code must retain the above copyright notice,
17       this list of conditions and the following disclaimer.
18 
19     * Redistributions in binary form must reproduce the above copyright
20       notice, this list of conditions and the following disclaimer in the
21       documentation and/or other materials provided with the distribution.
22 
23     * Neither the name of the University of Cambridge nor the names of its
24       contributors may be used to endorse or promote products derived from
25       this software without specific prior written permission.
26 
27 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
28 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
31 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 POSSIBILITY OF SUCH DAMAGE.
38 -----------------------------------------------------------------------------
39 */
40 
41 /* This module contains functions for serializing and deserializing
42 a sequence of compiled codes. */
43 
44 
45 #ifdef HAVE_CONFIG_H
46 #include "config.h"
47 #endif
48 
49 
50 #include "pcre2_internal.h"
51 
52 /* Magic number to provide a small check against being handed junk. */
53 
54 #define SERIALIZED_DATA_MAGIC 0x50523253u
55 
56 /* Deserialization is limited to the current PCRE version and
57 character width. */
58 
59 #define SERIALIZED_DATA_VERSION \
60   ((PCRE2_MAJOR) | ((PCRE2_MINOR) << 16))
61 
62 #define SERIALIZED_DATA_CONFIG \
63   (sizeof(PCRE2_UCHAR) | ((sizeof(void*)) << 8) | ((sizeof(PCRE2_SIZE)) << 16))
64 
65 
66 
67 /*************************************************
68 *           Serialize compiled patterns          *
69 *************************************************/
70 
71 PCRE2_EXP_DEFN int32_t PCRE2_CALL_CONVENTION
pcre2_serialize_encode(const pcre2_code ** codes,int32_t number_of_codes,uint8_t ** serialized_bytes,PCRE2_SIZE * serialized_size,pcre2_general_context * gcontext)72 pcre2_serialize_encode(const pcre2_code **codes, int32_t number_of_codes,
73    uint8_t **serialized_bytes, PCRE2_SIZE *serialized_size,
74    pcre2_general_context *gcontext)
75 {
76 uint8_t *bytes;
77 uint8_t *dst_bytes;
78 int32_t i;
79 PCRE2_SIZE total_size;
80 const pcre2_real_code *re;
81 const uint8_t *tables;
82 pcre2_serialized_data *data;
83 
84 const pcre2_memctl *memctl = (gcontext != NULL) ?
85   &gcontext->memctl : &PRIV(default_compile_context).memctl;
86 
87 if (codes == NULL || serialized_bytes == NULL || serialized_size == NULL)
88   return PCRE2_ERROR_NULL;
89 
90 if (number_of_codes <= 0) return PCRE2_ERROR_BADDATA;
91 
92 /* Compute total size. */
93 total_size = sizeof(pcre2_serialized_data) + TABLES_LENGTH;
94 tables = NULL;
95 
96 for (i = 0; i < number_of_codes; i++)
97   {
98   if (codes[i] == NULL) return PCRE2_ERROR_NULL;
99   re = (const pcre2_real_code *)(codes[i]);
100   if (re->magic_number != MAGIC_NUMBER) return PCRE2_ERROR_BADMAGIC;
101   if (tables == NULL)
102     tables = re->tables;
103   else if (tables != re->tables)
104     return PCRE2_ERROR_MIXEDTABLES;
105   total_size += re->blocksize;
106   }
107 
108 /* Initialize the byte stream. */
109 bytes = memctl->malloc(total_size + sizeof(pcre2_memctl), memctl->memory_data);
110 if (bytes == NULL) return PCRE2_ERROR_NOMEMORY;
111 
112 /* The controller is stored as a hidden parameter. */
113 memcpy(bytes, memctl, sizeof(pcre2_memctl));
114 bytes += sizeof(pcre2_memctl);
115 
116 data = (pcre2_serialized_data *)bytes;
117 data->magic = SERIALIZED_DATA_MAGIC;
118 data->version = SERIALIZED_DATA_VERSION;
119 data->config = SERIALIZED_DATA_CONFIG;
120 data->number_of_codes = number_of_codes;
121 
122 /* Copy all compiled code data. */
123 dst_bytes = bytes + sizeof(pcre2_serialized_data);
124 memcpy(dst_bytes, tables, TABLES_LENGTH);
125 dst_bytes += TABLES_LENGTH;
126 
127 for (i = 0; i < number_of_codes; i++)
128   {
129   re = (const pcre2_real_code *)(codes[i]);
130   (void)memcpy(dst_bytes, (char *)re, re->blocksize);
131 
132   /* Certain fields in the compiled code block are re-set during
133   deserialization. In order to ensure that the serialized data stream is always
134   the same for the same pattern, set them to zero here. We can't assume the
135   copy of the pattern is correctly aligned for accessing the fields as part of
136   a structure. Note the use of sizeof(void *) in the second of these, to
137   specify the size of a pointer. If sizeof(uint8_t *) is used (tables is a
138   pointer to uint8_t), gcc gives a warning because the first argument is also a
139   pointer to uint8_t. Casting the first argument to (void *) can stop this, but
140   it didn't stop Coverity giving the same complaint. */
141 
142   (void)memset(dst_bytes + offsetof(pcre2_real_code, memctl), 0,
143     sizeof(pcre2_memctl));
144   (void)memset(dst_bytes + offsetof(pcre2_real_code, tables), 0,
145     sizeof(void *));
146   (void)memset(dst_bytes + offsetof(pcre2_real_code, executable_jit), 0,
147     sizeof(void *));
148 
149   dst_bytes += re->blocksize;
150   }
151 
152 *serialized_bytes = bytes;
153 *serialized_size = total_size;
154 return number_of_codes;
155 }
156 
157 
158 /*************************************************
159 *          Deserialize compiled patterns         *
160 *************************************************/
161 
162 PCRE2_EXP_DEFN int32_t PCRE2_CALL_CONVENTION
pcre2_serialize_decode(pcre2_code ** codes,int32_t number_of_codes,const uint8_t * bytes,pcre2_general_context * gcontext)163 pcre2_serialize_decode(pcre2_code **codes, int32_t number_of_codes,
164    const uint8_t *bytes, pcre2_general_context *gcontext)
165 {
166 const pcre2_serialized_data *data = (const pcre2_serialized_data *)bytes;
167 const pcre2_memctl *memctl = (gcontext != NULL) ?
168   &gcontext->memctl : &PRIV(default_compile_context).memctl;
169 
170 const uint8_t *src_bytes;
171 pcre2_real_code *dst_re;
172 uint8_t *tables;
173 int32_t i, j;
174 
175 /* Sanity checks. */
176 
177 if (data == NULL || codes == NULL) return PCRE2_ERROR_NULL;
178 if (number_of_codes <= 0) return PCRE2_ERROR_BADDATA;
179 if (data->number_of_codes <= 0) return PCRE2_ERROR_BADSERIALIZEDDATA;
180 if (data->magic != SERIALIZED_DATA_MAGIC) return PCRE2_ERROR_BADMAGIC;
181 if (data->version != SERIALIZED_DATA_VERSION) return PCRE2_ERROR_BADMODE;
182 if (data->config != SERIALIZED_DATA_CONFIG) return PCRE2_ERROR_BADMODE;
183 
184 if (number_of_codes > data->number_of_codes)
185   number_of_codes = data->number_of_codes;
186 
187 src_bytes = bytes + sizeof(pcre2_serialized_data);
188 
189 /* Decode tables. The reference count for the tables is stored immediately
190 following them. */
191 
192 tables = memctl->malloc(TABLES_LENGTH + sizeof(PCRE2_SIZE), memctl->memory_data);
193 if (tables == NULL) return PCRE2_ERROR_NOMEMORY;
194 
195 memcpy(tables, src_bytes, TABLES_LENGTH);
196 *(PCRE2_SIZE *)(tables + TABLES_LENGTH) = number_of_codes;
197 src_bytes += TABLES_LENGTH;
198 
199 /* Decode the byte stream. We must not try to read the size from the compiled
200 code block in the stream, because it might be unaligned, which causes errors on
201 hardware such as Sparc-64 that doesn't like unaligned memory accesses. The type
202 of the blocksize field is given its own name to ensure that it is the same here
203 as in the block. */
204 
205 for (i = 0; i < number_of_codes; i++)
206   {
207   CODE_BLOCKSIZE_TYPE blocksize;
208   memcpy(&blocksize, src_bytes + offsetof(pcre2_real_code, blocksize),
209     sizeof(CODE_BLOCKSIZE_TYPE));
210   if (blocksize <= sizeof(pcre2_real_code))
211     return PCRE2_ERROR_BADSERIALIZEDDATA;
212 
213   /* The allocator provided by gcontext replaces the original one. */
214 
215   dst_re = (pcre2_real_code *)PRIV(memctl_malloc)(blocksize,
216     (pcre2_memctl *)gcontext);
217   if (dst_re == NULL)
218     {
219     memctl->free(tables, memctl->memory_data);
220     for (j = 0; j < i; j++)
221       {
222       memctl->free(codes[j], memctl->memory_data);
223       codes[j] = NULL;
224       }
225     return PCRE2_ERROR_NOMEMORY;
226     }
227 
228   /* The new allocator must be preserved. */
229 
230   memcpy(((uint8_t *)dst_re) + sizeof(pcre2_memctl),
231     src_bytes + sizeof(pcre2_memctl), blocksize - sizeof(pcre2_memctl));
232   if (dst_re->magic_number != MAGIC_NUMBER ||
233       dst_re->name_entry_size > MAX_NAME_SIZE + IMM2_SIZE + 1 ||
234       dst_re->name_count > MAX_NAME_COUNT)
235     {
236     memctl->free(dst_re, memctl->memory_data);
237     return PCRE2_ERROR_BADSERIALIZEDDATA;
238     }
239 
240   /* At the moment only one table is supported. */
241 
242   dst_re->tables = tables;
243   dst_re->executable_jit = NULL;
244   dst_re->flags |= PCRE2_DEREF_TABLES;
245 
246   codes[i] = dst_re;
247   src_bytes += blocksize;
248   }
249 
250 return number_of_codes;
251 }
252 
253 
254 /*************************************************
255 *    Get the number of serialized patterns       *
256 *************************************************/
257 
258 PCRE2_EXP_DEFN int32_t PCRE2_CALL_CONVENTION
pcre2_serialize_get_number_of_codes(const uint8_t * bytes)259 pcre2_serialize_get_number_of_codes(const uint8_t *bytes)
260 {
261 const pcre2_serialized_data *data = (const pcre2_serialized_data *)bytes;
262 
263 if (data == NULL) return PCRE2_ERROR_NULL;
264 if (data->magic != SERIALIZED_DATA_MAGIC) return PCRE2_ERROR_BADMAGIC;
265 if (data->version != SERIALIZED_DATA_VERSION) return PCRE2_ERROR_BADMODE;
266 if (data->config != SERIALIZED_DATA_CONFIG) return PCRE2_ERROR_BADMODE;
267 
268 return data->number_of_codes;
269 }
270 
271 
272 /*************************************************
273 *            Free the allocated stream           *
274 *************************************************/
275 
276 PCRE2_EXP_DEFN void PCRE2_CALL_CONVENTION
pcre2_serialize_free(uint8_t * bytes)277 pcre2_serialize_free(uint8_t *bytes)
278 {
279 if (bytes != NULL)
280   {
281   pcre2_memctl *memctl = (pcre2_memctl *)(bytes - sizeof(pcre2_memctl));
282   memctl->free(memctl, memctl->memory_data);
283   }
284 }
285 
286 /* End of pcre2_serialize.c */
287