1 /*
2 * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include "e_os.h"
11 #include "internal/cryptlib.h"
12 #include "crypto/cryptlib.h"
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <limits.h>
16 #include <openssl/crypto.h>
17 #ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
18 # include <execinfo.h>
19 #endif
20
21 /*
22 * the following pointers may be changed as long as 'allow_customize' is set
23 */
24 static int allow_customize = 1;
25
26 static void *(*malloc_impl)(size_t, const char *, int)
27 = CRYPTO_malloc;
28 static void *(*realloc_impl)(void *, size_t, const char *, int)
29 = CRYPTO_realloc;
30 static void (*free_impl)(void *, const char *, int)
31 = CRYPTO_free;
32
33 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
34 # include "internal/tsan_assist.h"
35
36 static TSAN_QUALIFIER int malloc_count;
37 static TSAN_QUALIFIER int realloc_count;
38 static TSAN_QUALIFIER int free_count;
39
40 # define INCREMENT(x) tsan_counter(&(x))
41
42 static char *md_failstring;
43 static long md_count;
44 static int md_fail_percent = 0;
45 static int md_tracefd = -1;
46 static int call_malloc_debug = 1;
47
48 static void parseit(void);
49 static int shouldfail(void);
50
51 # define FAILTEST() if (shouldfail()) return NULL
52
53 #else
54 static int call_malloc_debug = 0;
55
56 # define INCREMENT(x) /* empty */
57 # define FAILTEST() /* empty */
58 #endif
59
CRYPTO_set_mem_functions(void * (* m)(size_t,const char *,int),void * (* r)(void *,size_t,const char *,int),void (* f)(void *,const char *,int))60 int CRYPTO_set_mem_functions(
61 void *(*m)(size_t, const char *, int),
62 void *(*r)(void *, size_t, const char *, int),
63 void (*f)(void *, const char *, int))
64 {
65 if (!allow_customize)
66 return 0;
67 if (m)
68 malloc_impl = m;
69 if (r)
70 realloc_impl = r;
71 if (f)
72 free_impl = f;
73 return 1;
74 }
75
CRYPTO_set_mem_debug(int flag)76 int CRYPTO_set_mem_debug(int flag)
77 {
78 if (!allow_customize)
79 return 0;
80 call_malloc_debug = flag;
81 return 1;
82 }
83
CRYPTO_get_mem_functions(void * (** m)(size_t,const char *,int),void * (** r)(void *,size_t,const char *,int),void (** f)(void *,const char *,int))84 void CRYPTO_get_mem_functions(
85 void *(**m)(size_t, const char *, int),
86 void *(**r)(void *, size_t, const char *, int),
87 void (**f)(void *, const char *, int))
88 {
89 if (m != NULL)
90 *m = malloc_impl;
91 if (r != NULL)
92 *r = realloc_impl;
93 if (f != NULL)
94 *f = free_impl;
95 }
96
97 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
CRYPTO_get_alloc_counts(int * mcount,int * rcount,int * fcount)98 void CRYPTO_get_alloc_counts(int *mcount, int *rcount, int *fcount)
99 {
100 if (mcount != NULL)
101 *mcount = tsan_load(&malloc_count);
102 if (rcount != NULL)
103 *rcount = tsan_load(&realloc_count);
104 if (fcount != NULL)
105 *fcount = tsan_load(&free_count);
106 }
107
108 /*
109 * Parse a "malloc failure spec" string. This likes like a set of fields
110 * separated by semicolons. Each field has a count and an optional failure
111 * percentage. For example:
112 * 100@0;100@25;0@0
113 * or 100;100@25;0
114 * This means 100 mallocs succeed, then next 100 fail 25% of the time, and
115 * all remaining (count is zero) succeed.
116 */
parseit(void)117 static void parseit(void)
118 {
119 char *semi = strchr(md_failstring, ';');
120 char *atsign;
121
122 if (semi != NULL)
123 *semi++ = '\0';
124
125 /* Get the count (atol will stop at the @ if there), and percentage */
126 md_count = atol(md_failstring);
127 atsign = strchr(md_failstring, '@');
128 md_fail_percent = atsign == NULL ? 0 : atoi(atsign + 1);
129
130 if (semi != NULL)
131 md_failstring = semi;
132 }
133
134 /*
135 * Windows doesn't have random(), but it has rand()
136 * Some rand() implementations aren't good, but we're not
137 * dealing with secure randomness here.
138 */
139 # ifdef _WIN32
140 # define random() rand()
141 # endif
142 /*
143 * See if the current malloc should fail.
144 */
shouldfail(void)145 static int shouldfail(void)
146 {
147 int roll = (int)(random() % 100);
148 int shoulditfail = roll < md_fail_percent;
149 # ifndef _WIN32
150 /* suppressed on Windows as POSIX-like file descriptors are non-inheritable */
151 int len;
152 char buff[80];
153
154 if (md_tracefd > 0) {
155 BIO_snprintf(buff, sizeof(buff),
156 "%c C%ld %%%d R%d\n",
157 shoulditfail ? '-' : '+', md_count, md_fail_percent, roll);
158 len = strlen(buff);
159 if (write(md_tracefd, buff, len) != len)
160 perror("shouldfail write failed");
161 # ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
162 if (shoulditfail) {
163 void *addrs[30];
164 int num = backtrace(addrs, OSSL_NELEM(addrs));
165
166 backtrace_symbols_fd(addrs, num, md_tracefd);
167 }
168 # endif
169 }
170 # endif
171
172 if (md_count) {
173 /* If we used up this one, go to the next. */
174 if (--md_count == 0)
175 parseit();
176 }
177
178 return shoulditfail;
179 }
180
ossl_malloc_setup_failures(void)181 void ossl_malloc_setup_failures(void)
182 {
183 const char *cp = getenv("OPENSSL_MALLOC_FAILURES");
184
185 if (cp != NULL && (md_failstring = strdup(cp)) != NULL)
186 parseit();
187 if ((cp = getenv("OPENSSL_MALLOC_FD")) != NULL)
188 md_tracefd = atoi(cp);
189 }
190 #endif
191
CRYPTO_malloc(size_t num,const char * file,int line)192 void *CRYPTO_malloc(size_t num, const char *file, int line)
193 {
194 void *ret = NULL;
195
196 INCREMENT(malloc_count);
197 if (malloc_impl != NULL && malloc_impl != CRYPTO_malloc)
198 return malloc_impl(num, file, line);
199
200 if (num == 0)
201 return NULL;
202
203 FAILTEST();
204 if (allow_customize) {
205 /*
206 * Disallow customization after the first allocation. We only set this
207 * if necessary to avoid a store to the same cache line on every
208 * allocation.
209 */
210 allow_customize = 0;
211 }
212 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
213 if (call_malloc_debug) {
214 CRYPTO_mem_debug_malloc(NULL, num, 0, file, line);
215 ret = malloc(num);
216 CRYPTO_mem_debug_malloc(ret, num, 1, file, line);
217 } else {
218 ret = malloc(num);
219 }
220 #else
221 (void)(file); (void)(line);
222 ret = malloc(num);
223 #endif
224
225 return ret;
226 }
227
CRYPTO_zalloc(size_t num,const char * file,int line)228 void *CRYPTO_zalloc(size_t num, const char *file, int line)
229 {
230 void *ret = CRYPTO_malloc(num, file, line);
231
232 FAILTEST();
233 if (ret != NULL)
234 memset(ret, 0, num);
235 return ret;
236 }
237
CRYPTO_realloc(void * str,size_t num,const char * file,int line)238 void *CRYPTO_realloc(void *str, size_t num, const char *file, int line)
239 {
240 INCREMENT(realloc_count);
241 if (realloc_impl != NULL && realloc_impl != &CRYPTO_realloc)
242 return realloc_impl(str, num, file, line);
243
244 FAILTEST();
245 if (str == NULL)
246 return CRYPTO_malloc(num, file, line);
247
248 if (num == 0) {
249 CRYPTO_free(str, file, line);
250 return NULL;
251 }
252
253 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
254 if (call_malloc_debug) {
255 void *ret;
256 CRYPTO_mem_debug_realloc(str, NULL, num, 0, file, line);
257 ret = realloc(str, num);
258 CRYPTO_mem_debug_realloc(str, ret, num, 1, file, line);
259 return ret;
260 }
261 #else
262 (void)(file); (void)(line);
263 #endif
264 return realloc(str, num);
265
266 }
267
CRYPTO_clear_realloc(void * str,size_t old_len,size_t num,const char * file,int line)268 void *CRYPTO_clear_realloc(void *str, size_t old_len, size_t num,
269 const char *file, int line)
270 {
271 void *ret = NULL;
272
273 if (str == NULL)
274 return CRYPTO_malloc(num, file, line);
275
276 if (num == 0) {
277 CRYPTO_clear_free(str, old_len, file, line);
278 return NULL;
279 }
280
281 /* Can't shrink the buffer since memcpy below copies |old_len| bytes. */
282 if (num < old_len) {
283 OPENSSL_cleanse((char*)str + num, old_len - num);
284 return str;
285 }
286
287 ret = CRYPTO_malloc(num, file, line);
288 if (ret != NULL) {
289 memcpy(ret, str, old_len);
290 CRYPTO_clear_free(str, old_len, file, line);
291 }
292 return ret;
293 }
294
CRYPTO_free(void * str,const char * file,int line)295 void CRYPTO_free(void *str, const char *file, int line)
296 {
297 INCREMENT(free_count);
298 if (free_impl != NULL && free_impl != &CRYPTO_free) {
299 free_impl(str, file, line);
300 return;
301 }
302
303 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
304 if (call_malloc_debug) {
305 CRYPTO_mem_debug_free(str, 0, file, line);
306 free(str);
307 CRYPTO_mem_debug_free(str, 1, file, line);
308 } else {
309 free(str);
310 }
311 #else
312 free(str);
313 #endif
314 }
315
CRYPTO_clear_free(void * str,size_t num,const char * file,int line)316 void CRYPTO_clear_free(void *str, size_t num, const char *file, int line)
317 {
318 if (str == NULL)
319 return;
320 if (num)
321 OPENSSL_cleanse(str, num);
322 CRYPTO_free(str, file, line);
323 }
324