crypto/mem.c

   1 /*
   2  * Copyright 1995-2022 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 "internal/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 static CRYPTO_malloc_fn malloc_impl = CRYPTO_malloc;
  23 static CRYPTO_realloc_fn realloc_impl = CRYPTO_realloc;
  24 static CRYPTO_free_fn free_impl = CRYPTO_free;
  25
  26 #if !defined(OPENSSL_NO_CRYPTO_MDEBUG) && !defined(FIPS_MODULE)
  27 # include "internal/tsan_assist.h"
  28
  29 # ifdef TSAN_REQUIRES_LOCKING
  30 #  define INCREMENT(x) /* empty */
  31 #  define LOAD(x) 0
  32 # else  /* TSAN_REQUIRES_LOCKING */
  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 #  define LOAD(x)      tsan_load(&x)
  39 # endif /* TSAN_REQUIRES_LOCKING */
  40
  41 static char *md_failstring;
  42 static long md_count;
  43 static int md_fail_percent = 0;
  44 static int md_tracefd = -1;
  45
  46 static void parseit(void);
  47 static int shouldfail(void);
  48
  49 # define FAILTEST() if (shouldfail()) return NULL
  50
  51 #else
  52
  53 # define INCREMENT(x) /* empty */
  54 # define FAILTEST() /* empty */
  55 #endif
  56
  57 int CRYPTO_set_mem_functions(CRYPTO_malloc_fn malloc_fn,
  58                              CRYPTO_realloc_fn realloc_fn,
  59                              CRYPTO_free_fn free_fn)
  60 {
  61     if (!allow_customize)
  62         return 0;
  63     if (malloc_fn != NULL)
  64         malloc_impl = malloc_fn;
  65     if (realloc_fn != NULL)
  66         realloc_impl = realloc_fn;
  67     if (free_fn != NULL)
  68         free_impl = free_fn;
  69     return 1;
  70 }
  71
  72 void CRYPTO_get_mem_functions(CRYPTO_malloc_fn *malloc_fn,
  73                               CRYPTO_realloc_fn *realloc_fn,
  74                               CRYPTO_free_fn *free_fn)
  75 {
  76     if (malloc_fn != NULL)
  77         *malloc_fn = malloc_impl;
  78     if (realloc_fn != NULL)
  79         *realloc_fn = realloc_impl;
  80     if (free_fn != NULL)
  81         *free_fn = free_impl;
  82 }
  83
  84 #if !defined(OPENSSL_NO_CRYPTO_MDEBUG) && !defined(FIPS_MODULE)
  85 void CRYPTO_get_alloc_counts(int *mcount, int *rcount, int *fcount)
  86 {
  87     if (mcount != NULL)
  88         *mcount = LOAD(malloc_count);
  89     if (rcount != NULL)
  90         *rcount = LOAD(realloc_count);
  91     if (fcount != NULL)
  92         *fcount = 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     INCREMENT(malloc_count);
 174     if (malloc_impl != CRYPTO_malloc)
 175         return malloc_impl(num, file, line);
 176
 177     if (num == 0)
 178         return NULL;
 179
 180     FAILTEST();
 181     if (allow_customize) {
 182         /*
 183          * Disallow customization after the first allocation. We only set this
 184          * if necessary to avoid a store to the same cache line on every
 185          * allocation.
 186          */
 187         allow_customize = 0;
 188     }
 189
 190     return malloc(num);
 191 }
 192
 193 void *CRYPTO_zalloc(size_t num, const char *file, int line)
 194 {
 195     void *ret;
 196
 197     ret = CRYPTO_malloc(num, file, line);
 198     FAILTEST();
 199     if (ret != NULL)
 200         memset(ret, 0, num);
 201
 202     return ret;
 203 }
 204
 205 void *CRYPTO_realloc(void *str, size_t num, const char *file, int line)
 206 {
 207     INCREMENT(realloc_count);
 208     if (realloc_impl != CRYPTO_realloc)
 209         return realloc_impl(str, num, file, line);
 210
 211     FAILTEST();
 212     if (str == NULL)
 213         return CRYPTO_malloc(num, file, line);
 214
 215     if (num == 0) {
 216         CRYPTO_free(str, file, line);
 217         return NULL;
 218     }
 219
 220     return realloc(str, num);
 221 }
 222
 223 void *CRYPTO_clear_realloc(void *str, size_t old_len, size_t num,
 224                            const char *file, int line)
 225 {
 226     void *ret = NULL;
 227
 228     if (str == NULL)
 229         return CRYPTO_malloc(num, file, line);
 230
 231     if (num == 0) {
 232         CRYPTO_clear_free(str, old_len, file, line);
 233         return NULL;
 234     }
 235
 236     /* Can't shrink the buffer since memcpy below copies |old_len| bytes. */
 237     if (num < old_len) {
 238         OPENSSL_cleanse((char*)str + num, old_len - num);
 239         return str;
 240     }
 241
 242     ret = CRYPTO_malloc(num, file, line);
 243     if (ret != NULL) {
 244         memcpy(ret, str, old_len);
 245         CRYPTO_clear_free(str, old_len, file, line);
 246     }
 247     return ret;
 248 }
 249
 250 void CRYPTO_free(void *str, const char *file, int line)
 251 {
 252     INCREMENT(free_count);
 253     if (free_impl != CRYPTO_free) {
 254         free_impl(str, file, line);
 255         return;
 256     }
 257
 258     free(str);
 259 }
 260
 261 void CRYPTO_clear_free(void *str, size_t num, const char *file, int line)
 262 {
 263     if (str == NULL)
 264         return;
 265     if (num)
 266         OPENSSL_cleanse(str, num);
 267     CRYPTO_free(str, file, line);
 268 }
 269
 270 #if !defined(OPENSSL_NO_CRYPTO_MDEBUG)
 271
 272 # ifndef OPENSSL_NO_DEPRECATED_3_0
 273 int CRYPTO_mem_ctrl(int mode)
 274 {
 275     (void)mode;
 276     return -1;
 277 }
 278
 279 int CRYPTO_set_mem_debug(int flag)
 280 {
 281     (void)flag;
 282     return -1;
 283 }
 284
 285 int CRYPTO_mem_debug_push(const char *info, const char *file, int line)
 286 {
 287     (void)info; (void)file; (void)line;
 288     return 0;
 289 }
 290
 291 int CRYPTO_mem_debug_pop(void)
 292 {
 293     return 0;
 294 }
 295
 296 void CRYPTO_mem_debug_malloc(void *addr, size_t num, int flag,
 297                              const char *file, int line)
 298 {
 299     (void)addr; (void)num; (void)flag; (void)file; (void)line;
 300 }
 301
 302 void CRYPTO_mem_debug_realloc(void *addr1, void *addr2, size_t num, int flag,
 303                               const char *file, int line)
 304 {
 305     (void)addr1; (void)addr2; (void)num; (void)flag; (void)file; (void)line;
 306 }
 307
 308 void CRYPTO_mem_debug_free(void *addr, int flag,
 309                            const char *file, int line)
 310 {
 311     (void)addr; (void)flag; (void)file; (void)line;
 312 }
 313
 314 int CRYPTO_mem_leaks(BIO *b)
 315 {
 316     (void)b;
 317     return -1;
 318 }
 319
 320 #  ifndef OPENSSL_NO_STDIO
 321 int CRYPTO_mem_leaks_fp(FILE *fp)
 322 {
 323     (void)fp;
 324     return -1;
 325 }
 326 #  endif
 327
 328 int CRYPTO_mem_leaks_cb(int (*cb)(const char *str, size_t len, void *u),
 329                         void *u)
 330 {
 331     (void)cb; (void)u;
 332     return -1;
 333 }
 334
 335 # endif
 336
 337 #endif