crypto/buffer/buffer.c

   1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   2  * All rights reserved.
   3  *
   4  * This package is an SSL implementation written
   5  * by Eric Young (eay@cryptsoft.com).
   6  * The implementation was written so as to conform with Netscapes SSL.
   7  *
   8  * This library is free for commercial and non-commercial use as long as
   9  * the following conditions are aheared to.  The following conditions
  10  * apply to all code found in this distribution, be it the RC4, RSA,
  11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  12  * included with this distribution is covered by the same copyright terms
  13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  14  *
  15  * Copyright remains Eric Young's, and as such any Copyright notices in
  16  * the code are not to be removed.
  17  * If this package is used in a product, Eric Young should be given attribution
  18  * as the author of the parts of the library used.
  19  * This can be in the form of a textual message at program startup or
  20  * in documentation (online or textual) provided with the package.
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  * 1. Redistributions of source code must retain the copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  * 2. Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in the
  29  *    documentation and/or other materials provided with the distribution.
  30  * 3. All advertising materials mentioning features or use of this software
  31  *    must display the following acknowledgement:
  32  *    "This product includes cryptographic software written by
  33  *     Eric Young (eay@cryptsoft.com)"
  34  *    The word 'cryptographic' can be left out if the rouines from the library
  35  *    being used are not cryptographic related :-).
  36  * 4. If you include any Windows specific code (or a derivative thereof) from
  37  *    the apps directory (application code) you must include an acknowledgement:
  38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  50  * SUCH DAMAGE.
  51  *
  52  * The licence and distribution terms for any publically available version or
  53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  54  * copied and put under another distribution licence
  55  * [including the GNU Public Licence.]
  56  */
  57
  58 #include <stdio.h>
  59 #include "internal/cryptlib.h"
  60 #include <openssl/buffer.h>
  61
  62 /*
  63  * LIMIT_BEFORE_EXPANSION is the maximum n such that (n+3)/3*4 < 2**31. That
  64  * function is applied in several functions in this file and this limit
  65  * ensures that the result fits in an int.
  66  */
  67 #define LIMIT_BEFORE_EXPANSION 0x5ffffffc
  68
  69 BUF_MEM *BUF_MEM_new_ex(unsigned long flags)
  70 {
  71     BUF_MEM *ret;
  72
  73     ret = BUF_MEM_new();
  74     if (ret != NULL)
  75         ret->flags = flags;
  76     return (ret);
  77 }
  78
  79 BUF_MEM *BUF_MEM_new(void)
  80 {
  81     BUF_MEM *ret;
  82
  83     ret = OPENSSL_zalloc(sizeof(*ret));
  84     if (ret == NULL) {
  85         BUFerr(BUF_F_BUF_MEM_NEW, ERR_R_MALLOC_FAILURE);
  86         return (NULL);
  87     }
  88     return (ret);
  89 }
  90
  91 void BUF_MEM_free(BUF_MEM *a)
  92 {
  93     if (a == NULL)
  94         return;
  95
  96     if (a->data != NULL) {
  97         memset(a->data, 0, (unsigned int)a->max);
  98         if (a->flags & BUF_MEM_FLAG_SECURE)
  99             OPENSSL_secure_free(a->data);
 100         else
 101             OPENSSL_clear_free(a->data, a->max);
 102     }
 103     OPENSSL_free(a);
 104 }
 105
 106 /* Allocate a block of secure memory; copy over old data if there
 107  * was any, and then free it. */
 108 static char *sec_alloc_realloc(BUF_MEM *str, size_t len)
 109 {
 110     char *ret;
 111
 112     ret = OPENSSL_secure_malloc(len);
 113     if (str->data != NULL) {
 114         if (ret != NULL)
 115             memcpy(ret, str->data, str->length);
 116         OPENSSL_secure_free(str->data);
 117     }
 118     return (ret);
 119 }
 120
 121 size_t BUF_MEM_grow(BUF_MEM *str, size_t len)
 122 {
 123     char *ret;
 124     size_t n;
 125
 126     if (str->length >= len) {
 127         str->length = len;
 128         return (len);
 129     }
 130     if (str->max >= len) {
 131         memset(&str->data[str->length], 0, len - str->length);
 132         str->length = len;
 133         return (len);
 134     }
 135     /* This limit is sufficient to ensure (len+3)/3*4 < 2**31 */
 136     if (len > LIMIT_BEFORE_EXPANSION) {
 137         BUFerr(BUF_F_BUF_MEM_GROW, ERR_R_MALLOC_FAILURE);
 138         return 0;
 139     }
 140     n = (len + 3) / 3 * 4;
 141     if ((str->flags & BUF_MEM_FLAG_SECURE))
 142         ret = sec_alloc_realloc(str, n);
 143     else
 144         ret = OPENSSL_realloc(str->data, n);
 145     if (ret == NULL) {
 146         BUFerr(BUF_F_BUF_MEM_GROW, ERR_R_MALLOC_FAILURE);
 147         len = 0;
 148     } else {
 149         str->data = ret;
 150         str->max = n;
 151         memset(&str->data[str->length], 0, len - str->length);
 152         str->length = len;
 153     }
 154     return (len);
 155 }
 156
 157 size_t BUF_MEM_grow_clean(BUF_MEM *str, size_t len)
 158 {
 159     char *ret;
 160     size_t n;
 161
 162     if (str->length >= len) {
 163         memset(&str->data[len], 0, str->length - len);
 164         str->length = len;
 165         return (len);
 166     }
 167     if (str->max >= len) {
 168         memset(&str->data[str->length], 0, len - str->length);
 169         str->length = len;
 170         return (len);
 171     }
 172     /* This limit is sufficient to ensure (len+3)/3*4 < 2**31 */
 173     if (len > LIMIT_BEFORE_EXPANSION) {
 174         BUFerr(BUF_F_BUF_MEM_GROW_CLEAN, ERR_R_MALLOC_FAILURE);
 175         return 0;
 176     }
 177     n = (len + 3) / 3 * 4;
 178     if ((str->flags & BUF_MEM_FLAG_SECURE))
 179         ret = sec_alloc_realloc(str, n);
 180     else
 181         ret = OPENSSL_clear_realloc(str->data, str->max, n);
 182     if (ret == NULL) {
 183         BUFerr(BUF_F_BUF_MEM_GROW_CLEAN, ERR_R_MALLOC_FAILURE);
 184         len = 0;
 185     } else {
 186         str->data = ret;
 187         str->max = n;
 188         memset(&str->data[str->length], 0, len - str->length);
 189         str->length = len;
 190     }
 191     return (len);
 192 }
 193
 194 void BUF_reverse(unsigned char *out, unsigned char *in, size_t size)
 195 {
 196     size_t i;
 197     if (in) {
 198         out += size - 1;
 199         for (i = 0; i < size; i++)
 200             *out-- = *in++;
 201     } else {
 202         unsigned char *q;
 203         char c;
 204         q = out + size - 1;
 205         for (i = 0; i < size / 2; i++) {
 206             c = *q;
 207             *q-- = *out;
 208             *out++ = c;
 209         }
 210     }
 211 }