Strictly memwipe_check() for magic only in the affected buffer
[strongswan.git] / src / libstrongswan / library.c
1 /*
2 * Copyright (C) 2009 Tobias Brunner
3 * Copyright (C) 2008 Martin Willi
4 * Hochschule fuer Technik Rapperswil
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * for more details.
15 */
16
17 #include "library.h"
18
19 #include <stdlib.h>
20
21 #include <utils/debug.h>
22 #include <threading/thread.h>
23 #include <utils/identification.h>
24 #include <networking/host.h>
25 #include <collections/hashtable.h>
26 #include <utils/backtrace.h>
27 #include <selectors/traffic_selector.h>
28
29 #define CHECKSUM_LIBRARY IPSEC_LIB_DIR"/libchecksum.so"
30
31 typedef struct private_library_t private_library_t;
32
33 /**
34 * private data of library
35 */
36 struct private_library_t {
37
38 /**
39 * public functions
40 */
41 library_t public;
42
43 /**
44 * Hashtable with registered objects (name => object)
45 */
46 hashtable_t *objects;
47
48 /**
49 * Integrity check failed?
50 */
51 bool integrity_failed;
52
53 /**
54 * Number of times we have been initialized
55 */
56 refcount_t ref;
57 };
58
59 /**
60 * library instance
61 */
62 library_t *lib = NULL;
63
64 /**
65 * Deinitialize library
66 */
67 void library_deinit()
68 {
69 private_library_t *this = (private_library_t*)lib;
70 bool detailed;
71
72 if (!this || !ref_put(&this->ref))
73 { /* have more users */
74 return;
75 }
76
77 detailed = lib->settings->get_bool(lib->settings,
78 "libstrongswan.leak_detective.detailed", TRUE);
79
80 /* make sure the cache is clear before unloading plugins */
81 lib->credmgr->flush_cache(lib->credmgr, CERT_ANY);
82
83 this->public.scheduler->destroy(this->public.scheduler);
84 this->public.processor->destroy(this->public.processor);
85 this->public.plugins->destroy(this->public.plugins);
86 this->public.hosts->destroy(this->public.hosts);
87 this->public.settings->destroy(this->public.settings);
88 this->public.credmgr->destroy(this->public.credmgr);
89 this->public.creds->destroy(this->public.creds);
90 this->public.encoding->destroy(this->public.encoding);
91 this->public.crypto->destroy(this->public.crypto);
92 this->public.proposal->destroy(this->public.proposal);
93 this->public.fetcher->destroy(this->public.fetcher);
94 this->public.resolver->destroy(this->public.resolver);
95 this->public.db->destroy(this->public.db);
96 this->public.printf_hook->destroy(this->public.printf_hook);
97 this->objects->destroy(this->objects);
98 if (this->public.integrity)
99 {
100 this->public.integrity->destroy(this->public.integrity);
101 }
102
103 if (lib->leak_detective)
104 {
105 lib->leak_detective->report(lib->leak_detective, detailed);
106 lib->leak_detective->destroy(lib->leak_detective);
107 }
108
109 threads_deinit();
110 backtrace_deinit();
111
112 free(this);
113 lib = NULL;
114 }
115
116 METHOD(library_t, get, void*,
117 private_library_t *this, char *name)
118 {
119 return this->objects->get(this->objects, name);
120 }
121
122 METHOD(library_t, set, bool,
123 private_library_t *this, char *name, void *object)
124 {
125 if (object)
126 {
127 if (this->objects->get(this->objects, name))
128 {
129 return FALSE;
130 }
131 this->objects->put(this->objects, name, object);
132 return TRUE;
133 }
134 return this->objects->remove(this->objects, name) != NULL;
135 }
136
137 /**
138 * Hashtable hash function
139 */
140 static u_int hash(char *key)
141 {
142 return chunk_hash(chunk_create(key, strlen(key)));
143 }
144
145 /**
146 * Hashtable equals function
147 */
148 static bool equals(char *a, char *b)
149 {
150 return streq(a, b);
151 }
152
153 /**
154 * Number of words we write and memwipe() in memwipe check
155 */
156 #define MEMWIPE_WIPE_WORDS 16
157
158 /**
159 * Write magic to memory, and try to clear it with memwipe()
160 */
161 __attribute__((noinline))
162 static void do_magic(int *magic, int **out)
163 {
164 int buf[MEMWIPE_WIPE_WORDS], i;
165
166 *out = buf;
167 for (i = 0; i < countof(buf); i++)
168 {
169 buf[i] = *magic;
170 }
171 /* passing buf to dbg should make sure the compiler can't optimize out buf.
172 * we use directly dbg(3), as DBG3() might be stripped with DEBUG_LEVEL. */
173 dbg(DBG_LIB, 3, "memwipe() pre: %b", buf, sizeof(buf));
174 memwipe(buf, sizeof(buf));
175 }
176
177 /**
178 * Check if memwipe works as expected
179 */
180 static bool check_memwipe()
181 {
182 int magic = 0xCAFEBABE, *buf, i;
183
184 do_magic(&magic, &buf);
185
186 for (i = 0; i < MEMWIPE_WIPE_WORDS; i++)
187 {
188 if (buf[i] == magic)
189 {
190 DBG1(DBG_LIB, "memwipe() check failed: stackdir: %b",
191 buf, MEMWIPE_WIPE_WORDS * sizeof(int));
192 return FALSE;
193 }
194 }
195 return TRUE;
196 }
197
198 /*
199 * see header file
200 */
201 bool library_init(char *settings)
202 {
203 private_library_t *this;
204 printf_hook_t *pfh;
205
206 if (lib)
207 { /* already initialized, increase refcount */
208 this = (private_library_t*)lib;
209 ref_get(&this->ref);
210 return !this->integrity_failed;
211 }
212
213 INIT(this,
214 .public = {
215 .get = _get,
216 .set = _set,
217 },
218 .ref = 1,
219 );
220 lib = &this->public;
221
222 backtrace_init();
223 threads_init();
224
225 #ifdef LEAK_DETECTIVE
226 lib->leak_detective = leak_detective_create();
227 #endif /* LEAK_DETECTIVE */
228
229 pfh = printf_hook_create();
230 this->public.printf_hook = pfh;
231
232 pfh->add_handler(pfh, 'b', mem_printf_hook,
233 PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_INT,
234 PRINTF_HOOK_ARGTYPE_END);
235 pfh->add_handler(pfh, 'B', chunk_printf_hook,
236 PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_END);
237 pfh->add_handler(pfh, 'H', host_printf_hook,
238 PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_END);
239 pfh->add_handler(pfh, 'N', enum_printf_hook,
240 PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_INT,
241 PRINTF_HOOK_ARGTYPE_END);
242 pfh->add_handler(pfh, 'T', time_printf_hook,
243 PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_INT,
244 PRINTF_HOOK_ARGTYPE_END);
245 pfh->add_handler(pfh, 'V', time_delta_printf_hook,
246 PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_POINTER,
247 PRINTF_HOOK_ARGTYPE_END);
248 pfh->add_handler(pfh, 'Y', identification_printf_hook,
249 PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_END);
250 pfh->add_handler(pfh, 'R', traffic_selector_printf_hook,
251 PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_END);
252
253 this->objects = hashtable_create((hashtable_hash_t)hash,
254 (hashtable_equals_t)equals, 4);
255 this->public.settings = settings_create(settings);
256 this->public.hosts = host_resolver_create();
257 this->public.proposal = proposal_keywords_create();
258 this->public.crypto = crypto_factory_create();
259 this->public.creds = credential_factory_create();
260 this->public.credmgr = credential_manager_create();
261 this->public.encoding = cred_encoding_create();
262 this->public.fetcher = fetcher_manager_create();
263 this->public.resolver = resolver_manager_create();
264 this->public.db = database_factory_create();
265 this->public.processor = processor_create();
266 this->public.scheduler = scheduler_create();
267 this->public.plugins = plugin_loader_create();
268
269 if (!check_memwipe())
270 {
271 return FALSE;
272 }
273
274 if (lib->settings->get_bool(lib->settings,
275 "libstrongswan.integrity_test", FALSE))
276 {
277 #ifdef INTEGRITY_TEST
278 this->public.integrity = integrity_checker_create(CHECKSUM_LIBRARY);
279 if (!lib->integrity->check(lib->integrity, "libstrongswan", library_init))
280 {
281 DBG1(DBG_LIB, "integrity check of libstrongswan failed");
282 this->integrity_failed = TRUE;
283 }
284 #else /* !INTEGRITY_TEST */
285 DBG1(DBG_LIB, "integrity test enabled, but not supported");
286 this->integrity_failed = TRUE;
287 #endif /* INTEGRITY_TEST */
288 }
289
290 return !this->integrity_failed;
291 }