crypto/mem.c

   1 /*
   2  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (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
  18 /*
  19  * the following pointers may be changed as long as 'allow_customize' is set
  20  */
  21 static int allow_customize = 1;
  22
  23 static void *(*malloc_impl)(size_t, const char *, int)
  24     = CRYPTO_malloc;
  25 static void *(*realloc_impl)(void *, size_t, const char *, int)
  26     = CRYPTO_realloc;
  27 static void (*free_impl)(void *, const char *, int)
  28     = CRYPTO_free;
  29
  30 #if !defined(OPENSSL_NO_CRYPTO_MDEBUG) && !defined(FIPS_MODE)
  31 # include "internal/tsan_assist.h"
  32
  33 static TSAN_QUALIFIER int malloc_count;
  34 static TSAN_QUALIFIER int realloc_count;
  35 static TSAN_QUALIFIER int free_count;
  36
  37 # define INCREMENT(x) tsan_counter(&(x))
  38
  39 static char *md_failstring;
  40 static long md_count;
  41 static int md_fail_percent = 0;
  42 static int md_tracefd = -1;
  43
  44 static void parseit(void);
  45 static int shouldfail(void);
  46
  47 # define FAILTEST() if (shouldfail()) return NULL
  48
  49 #else
  50
  51 # define INCREMENT(x) /* empty */
  52 # define FAILTEST() /* empty */
  53 #endif
  54
  55 int CRYPTO_set_mem_functions(
  56         void *(*m)(size_t, const char *, int),
  57         void *(*r)(void *, size_t, const char *, int),
  58         void (*f)(void *, const char *, int))
  59 {
  60     if (!allow_customize)
  61         return 0;
  62     if (m)
  63         malloc_impl = m;
  64     if (r)
  65         realloc_impl = r;
  66     if (f)
  67         free_impl = f;
  68     return 1;
  69 }
  70
  71 void CRYPTO_get_mem_functions(
  72         void *(**m)(size_t, const char *, int),
  73         void *(**r)(void *, size_t, const char *, int),
  74         void (**f)(void *, const char *, int))
  75 {
  76     if (m != NULL)
  77         *m = malloc_impl;
  78     if (r != NULL)
  79         *r = realloc_impl;
  80     if (f != NULL)
  81         *f = free_impl;
  82 }
  83
  84 #if !defined(OPENSSL_NO_CRYPTO_MDEBUG) && !defined(FIPS_MODE)
  85 void CRYPTO_get_alloc_counts(int *mcount, int *rcount, int *fcount)
  86 {
  87     if (mcount != NULL)
  88         *mcount = tsan_load(&malloc_count);
  89     if (rcount != NULL)
  90         *rcount = tsan_load(&realloc_count);
  91     if (fcount != NULL)
  92         *fcount = tsan_load(&free_count);
  93 }
  94
  95 /*
  96  * Parse a "malloc failure spec" string.  This likes like a set of fields
  97  * separated by semicolons.  Each field has a count and an optional failure
  98  * percentage.  For example:
  99  *          100@0;100@25;0@0
 100  *    or    100;100@25;0
 101  * This means 100 mallocs succeed, then next 100 fail 25% of the time, and
 102  * all remaining (count is zero) succeed.
 103  */
 104 static void parseit(void)
 105 {
 106     char *semi = strchr(md_failstring, ';');
 107     char *atsign;
 108
 109     if (semi != NULL)
 110         *semi++ = '\0';
 111
 112     /* Get the count (atol will stop at the @ if there), and percentage */
 113     md_count = atol(md_failstring);
 114     atsign = strchr(md_failstring, '@');
 115     md_fail_percent = atsign == NULL ? 0 : atoi(atsign + 1);
 116
 117     if (semi != NULL)
 118         md_failstring = semi;
 119 }
 120
 121 /*
 122  * Windows doesn't have random(), but it has rand()
 123  * Some rand() implementations aren't good, but we're not
 124  * dealing with secure randomness here.
 125  */
 126 # ifdef _WIN32
 127 #  define random() rand()
 128 # endif
 129 /*
 130  * See if the current malloc should fail.
 131  */
 132 static int shouldfail(void)
 133 {
 134     int roll = (int)(random() % 100);
 135     int shoulditfail = roll < md_fail_percent;
 136 # ifndef _WIN32
 137 /* suppressed on Windows as POSIX-like file descriptors are non-inheritable */
 138     int len;
 139     char buff[80];
 140
 141     if (md_tracefd > 0) {
 142         BIO_snprintf(buff, sizeof(buff),
 143                      "%c C%ld %%%d R%d\n",
 144                      shoulditfail ? '-' : '+', md_count, md_fail_percent, roll);
 145         len = strlen(buff);
 146         if (write(md_tracefd, buff, len) != len)
 147             perror("shouldfail write failed");
 148     }
 149 # endif
 150
 151     if (md_count) {
 152         /* If we used up this one, go to the next. */
 153         if (--md_count == 0)
 154             parseit();
 155     }
 156
 157     return shoulditfail;
 158 }
 159
 160 void ossl_malloc_setup_failures(void)
 161 {
 162     const char *cp = getenv("OPENSSL_MALLOC_FAILURES");
 163
 164     if (cp != NULL && (md_failstring = strdup(cp)) != NULL)
 165         parseit();
 166     if ((cp = getenv("OPENSSL_MALLOC_FD")) != NULL)
 167         md_tracefd = atoi(cp);
 168 }
 169 #endif
 170
 171 void *CRYPTO_malloc(size_t num, const char *file, int line)
 172 {
 173     void *ret = NULL;
 174
 175     INCREMENT(malloc_count);
 176     if (malloc_impl != NULL && malloc_impl != CRYPTO_malloc)
 177         return malloc_impl(num, file, line);
 178
 179     if (num == 0)
 180         return NULL;
 181
 182     FAILTEST();
 183     if (allow_customize) {
 184         /*
 185          * Disallow customization after the first allocation. We only set this
 186          * if necessary to avoid a store to the same cache line on every
 187          * allocation.
 188          */
 189         allow_customize = 0;
 190     }
 191     (void)(file); (void)(line);
 192     ret = malloc(num);
 193
 194     return ret;
 195 }
 196
 197 void *CRYPTO_zalloc(size_t num, const char *file, int line)
 198 {
 199     void *ret = CRYPTO_malloc(num, file, line);
 200
 201     FAILTEST();
 202     if (ret != NULL)
 203         memset(ret, 0, num);
 204     return ret;
 205 }
 206
 207 void *CRYPTO_realloc(void *str, size_t num, const char *file, int line)
 208 {
 209     INCREMENT(realloc_count);
 210     if (realloc_impl != NULL && realloc_impl != &CRYPTO_realloc)
 211         return realloc_impl(str, num, file, line);
 212
 213     FAILTEST();
 214     if (str == NULL)
 215         return CRYPTO_malloc(num, file, line);
 216
 217     if (num == 0) {
 218         CRYPTO_free(str, file, line);
 219         return NULL;
 220     }
 221
 222     (void)(file); (void)(line);
 223     return realloc(str, num);
 224
 225 }
 226
 227 void *CRYPTO_clear_realloc(void *str, size_t old_len, size_t num,
 228                            const char *file, int line)
 229 {
 230     void *ret = NULL;
 231
 232     if (str == NULL)
 233         return CRYPTO_malloc(num, file, line);
 234
 235     if (num == 0) {
 236         CRYPTO_clear_free(str, old_len, file, line);
 237         return NULL;
 238     }
 239
 240     /* Can't shrink the buffer since memcpy below copies |old_len| bytes. */
 241     if (num < old_len) {
 242         OPENSSL_cleanse((char*)str + num, old_len - num);
 243         return str;
 244     }
 245
 246     ret = CRYPTO_malloc(num, file, line);
 247     if (ret != NULL) {
 248         memcpy(ret, str, old_len);
 249         CRYPTO_clear_free(str, old_len, file, line);
 250     }
 251     return ret;
 252 }
 253
 254 void CRYPTO_free(void *str, const char *file, int line)
 255 {
 256     INCREMENT(free_count);
 257     if (free_impl != NULL && free_impl != &CRYPTO_free) {
 258         free_impl(str, file, line);
 259         return;
 260     }
 261
 262     free(str);
 263 }
 264
 265 void CRYPTO_clear_free(void *str, size_t num, const char *file, int line)
 266 {
 267     if (str == NULL)
 268         return;
 269     if (num)
 270         OPENSSL_cleanse(str, num);
 271     CRYPTO_free(str, file, line);
 272 }
 273
 274 #if !defined(OPENSSL_NO_CRYPTO_MDEBUG)
 275
 276 # ifndef OPENSSL_NO_DEPRECATED_3_0
 277 int CRYPTO_mem_ctrl(int mode)
 278 {
 279     (void)mode;
 280     return -1;
 281 }
 282
 283 int CRYPTO_set_mem_debug(int flag)
 284 {
 285     (void)flag;
 286     return -1;
 287 }
 288
 289 int CRYPTO_mem_debug_push(const char *info, const char *file, int line)
 290 {
 291     (void)info; (void)file; (void)line;
 292     return -1;
 293 }
 294
 295 int CRYPTO_mem_debug_pop(void)
 296 {
 297     return -1;
 298 }
 299
 300 void CRYPTO_mem_debug_malloc(void *addr, size_t num, int flag,
 301                              const char *file, int line)
 302 {
 303     (void)addr; (void)num; (void)flag; (void)file; (void)line;
 304 }
 305
 306 void CRYPTO_mem_debug_realloc(void *addr1, void *addr2, size_t num, int flag,
 307                               const char *file, int line)
 308 {
 309     (void)addr1; (void)addr2; (void)num; (void)flag; (void)file; (void)line;
 310 }
 311
 312 void CRYPTO_mem_debug_free(void *addr, int flag,
 313                            const char *file, int line)
 314 {
 315     (void)addr; (void)flag; (void)file; (void)line;
 316 }
 317
 318 int CRYPTO_mem_leaks(BIO *b)
 319 {
 320     (void)b;
 321     return -1;
 322 }
 323
 324 #  ifndef OPENSSL_NO_STDIO
 325 int CRYPTO_mem_leaks_fp(FILE *fp)
 326 {
 327     (void)fp;
 328     return -1;
 329 }
 330 #  endif
 331
 332 int CRYPTO_mem_leaks_cb(int (*cb)(const char *str, size_t len, void *u),
 333                         void *u)
 334 {
 335     (void)cb; (void)u;
 336     return -1;
 337 }
 338
 339 # endif
 340
 341 #endif