crypto/mem.c

   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 <stdio.h>
  11 #include <stdlib.h>
  12 #include <limits.h>
  13 #include <openssl/crypto.h>
  14 #include "internal/cryptlib.h"
  15
  16 /*
  17  * the following pointers may be changed as long as 'allow_customize' is set
  18  */
  19 static int allow_customize = 1;
  20
  21 static void *(*malloc_impl)(size_t, const char *, int)
  22     = CRYPTO_malloc;
  23 static void *(*realloc_impl)(void *, size_t, const char *, int)
  24     = CRYPTO_realloc;
  25 static void (*free_impl)(void *, const char *, int)
  26     = CRYPTO_free;
  27
  28 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
  29 static int call_malloc_debug = 1;
  30 #else
  31 static int call_malloc_debug = 0;
  32 #endif
  33
  34 int CRYPTO_set_mem_functions(
  35         void *(*m)(size_t, const char *, int),
  36         void *(*r)(void *, size_t, const char *, int),
  37         void (*f)(void *, const char *, int))
  38 {
  39     if (!allow_customize)
  40         return 0;
  41     if (m)
  42         malloc_impl = m;
  43     if (r)
  44         realloc_impl = r;
  45     if (f)
  46         free_impl = f;
  47     return 1;
  48 }
  49
  50 int CRYPTO_set_mem_debug(int flag)
  51 {
  52     if (!allow_customize)
  53         return 0;
  54     call_malloc_debug = flag;
  55     return 1;
  56 }
  57
  58 void CRYPTO_get_mem_functions(
  59         void *(**m)(size_t, const char *, int),
  60         void *(**r)(void *, size_t, const char *, int),
  61         void (**f)(void *, const char *, int))
  62 {
  63     if (m != NULL)
  64         *m = malloc_impl;
  65     if (r != NULL)
  66         *r = realloc_impl;
  67     if (f != NULL)
  68         *f = free_impl;
  69 }
  70
  71 void *CRYPTO_malloc(size_t num, const char *file, int line)
  72 {
  73     void *ret = NULL;
  74
  75     if (malloc_impl != NULL && malloc_impl != CRYPTO_malloc)
  76         return malloc_impl(num, file, line);
  77
  78     if (num == 0)
  79         return NULL;
  80
  81     if (allow_customize) {
  82         /*
  83          * Disallow customization after the first allocation. We only set this
  84          * if necessary to avoid a store to the same cache line on every
  85          * allocation.
  86          */
  87         allow_customize = 0;
  88     }
  89 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
  90     if (call_malloc_debug) {
  91         CRYPTO_mem_debug_malloc(NULL, num, 0, file, line);
  92         ret = malloc(num);
  93         CRYPTO_mem_debug_malloc(ret, num, 1, file, line);
  94     } else {
  95         ret = malloc(num);
  96     }
  97 #else
  98     osslargused(file); osslargused(line);
  99     ret = malloc(num);
 100 #endif
 101
 102     return ret;
 103 }
 104
 105 void *CRYPTO_zalloc(size_t num, const char *file, int line)
 106 {
 107     void *ret = CRYPTO_malloc(num, file, line);
 108
 109     if (ret != NULL)
 110         memset(ret, 0, num);
 111     return ret;
 112 }
 113
 114 void *CRYPTO_realloc(void *str, size_t num, const char *file, int line)
 115 {
 116     if (realloc_impl != NULL && realloc_impl != &CRYPTO_realloc)
 117         return realloc_impl(str, num, file, line);
 118
 119     if (str == NULL)
 120         return CRYPTO_malloc(num, file, line);
 121
 122     if (num == 0) {
 123         CRYPTO_free(str, file, line);
 124         return NULL;
 125     }
 126
 127 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
 128     if (call_malloc_debug) {
 129         void *ret;
 130         CRYPTO_mem_debug_realloc(str, NULL, num, 0, file, line);
 131         ret = realloc(str, num);
 132         CRYPTO_mem_debug_realloc(str, ret, num, 1, file, line);
 133         return ret;
 134     }
 135 #else
 136     osslargused(file); osslargused(line);
 137 #endif
 138     return realloc(str, num);
 139
 140 }
 141
 142 void *CRYPTO_clear_realloc(void *str, size_t old_len, size_t num,
 143                            const char *file, int line)
 144 {
 145     void *ret = NULL;
 146
 147     if (str == NULL)
 148         return CRYPTO_malloc(num, file, line);
 149
 150     if (num == 0) {
 151         CRYPTO_clear_free(str, old_len, file, line);
 152         return NULL;
 153     }
 154
 155     /* Can't shrink the buffer since memcpy below copies |old_len| bytes. */
 156     if (num < old_len) {
 157         OPENSSL_cleanse((char*)str + num, old_len - num);
 158         return str;
 159     }
 160
 161     ret = CRYPTO_malloc(num, file, line);
 162     if (ret != NULL) {
 163         memcpy(ret, str, old_len);
 164         CRYPTO_clear_free(str, old_len, file, line);
 165     }
 166     return ret;
 167 }
 168
 169 void CRYPTO_free(void *str, const char *file, int line)
 170 {
 171     if (free_impl != NULL && free_impl != &CRYPTO_free) {
 172         free_impl(str, file, line);
 173         return;
 174     }
 175
 176 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
 177     if (call_malloc_debug) {
 178         CRYPTO_mem_debug_free(str, 0, file, line);
 179         free(str);
 180         CRYPTO_mem_debug_free(str, 1, file, line);
 181     } else {
 182         free(str);
 183     }
 184 #else
 185     free(str);
 186 #endif
 187 }
 188
 189 void CRYPTO_clear_free(void *str, size_t num, const char *file, int line)
 190 {
 191     if (str == NULL)
 192         return;
 193     if (num)
 194         OPENSSL_cleanse(str, num);
 195     CRYPTO_free(str, file, line);
 196 }