buffer.c revision 296465
1/* crypto/buffer/buffer.c */ 2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay@cryptsoft.com). 7 * The implementation was written so as to conform with Netscapes SSL. 8 * 9 * This library is free for commercial and non-commercial use as long as 10 * the following conditions are aheared to. The following conditions 11 * apply to all code found in this distribution, be it the RC4, RSA, 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13 * included with this distribution is covered by the same copyright terms 14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15 * 16 * Copyright remains Eric Young's, and as such any Copyright notices in 17 * the code are not to be removed. 18 * If this package is used in a product, Eric Young should be given attribution 19 * as the author of the parts of the library used. 20 * This can be in the form of a textual message at program startup or 21 * in documentation (online or textual) provided with the package. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 3. All advertising materials mentioning features or use of this software 32 * must display the following acknowledgement: 33 * "This product includes cryptographic software written by 34 * Eric Young (eay@cryptsoft.com)" 35 * The word 'cryptographic' can be left out if the rouines from the library 36 * being used are not cryptographic related :-). 37 * 4. If you include any Windows specific code (or a derivative thereof) from 38 * the apps directory (application code) you must include an acknowledgement: 39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40 * 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51 * SUCH DAMAGE. 52 * 53 * The licence and distribution terms for any publically available version or 54 * derivative of this code cannot be changed. i.e. this code cannot simply be 55 * copied and put under another distribution licence 56 * [including the GNU Public Licence.] 57 */ 58 59#include <stdio.h> 60#include "cryptlib.h" 61#include <openssl/buffer.h> 62 63/* 64 * LIMIT_BEFORE_EXPANSION is the maximum n such that (n+3)/3*4 < 2**31. That 65 * function is applied in several functions in this file and this limit 66 * ensures that the result fits in an int. 67 */ 68#define LIMIT_BEFORE_EXPANSION 0x5ffffffc 69 70BUF_MEM *BUF_MEM_new(void) 71{ 72 BUF_MEM *ret; 73 74 ret = OPENSSL_malloc(sizeof(BUF_MEM)); 75 if (ret == NULL) { 76 BUFerr(BUF_F_BUF_MEM_NEW, ERR_R_MALLOC_FAILURE); 77 return (NULL); 78 } 79 ret->length = 0; 80 ret->max = 0; 81 ret->data = NULL; 82 return (ret); 83} 84 85void BUF_MEM_free(BUF_MEM *a) 86{ 87 if (a == NULL) 88 return; 89 90 if (a->data != NULL) { 91 memset(a->data, 0, (unsigned int)a->max); 92 OPENSSL_free(a->data); 93 } 94 OPENSSL_free(a); 95} 96 97int BUF_MEM_grow(BUF_MEM *str, int len) 98{ 99 char *ret; 100 unsigned int n; 101 102 if (len < 0) { 103 BUFerr(BUF_F_BUF_MEM_GROW, ERR_R_MALLOC_FAILURE); 104 return 0; 105 } 106 if (str->length >= len) { 107 str->length = len; 108 return (len); 109 } 110 if (str->max >= len) { 111 memset(&str->data[str->length], 0, len - str->length); 112 str->length = len; 113 return (len); 114 } 115 /* This limit is sufficient to ensure (len+3)/3*4 < 2**31 */ 116 if (len > LIMIT_BEFORE_EXPANSION) { 117 BUFerr(BUF_F_BUF_MEM_GROW, ERR_R_MALLOC_FAILURE); 118 return 0; 119 } 120 n = (len + 3) / 3 * 4; 121 if (str->data == NULL) 122 ret = OPENSSL_malloc(n); 123 else 124 ret = OPENSSL_realloc(str->data, n); 125 if (ret == NULL) { 126 BUFerr(BUF_F_BUF_MEM_GROW, ERR_R_MALLOC_FAILURE); 127 len = 0; 128 } else { 129 str->data = ret; 130 str->max = n; 131 memset(&str->data[str->length], 0, len - str->length); 132 str->length = len; 133 } 134 return (len); 135} 136 137int BUF_MEM_grow_clean(BUF_MEM *str, int len) 138{ 139 char *ret; 140 unsigned int n; 141 142 if (len < 0) { 143 BUFerr(BUF_F_BUF_MEM_GROW_CLEAN, ERR_R_MALLOC_FAILURE); 144 return 0; 145 } 146 if (str->length >= len) { 147 memset(&str->data[len], 0, str->length - len); 148 str->length = len; 149 return (len); 150 } 151 if (str->max >= len) { 152 memset(&str->data[str->length], 0, len - str->length); 153 str->length = len; 154 return (len); 155 } 156 /* This limit is sufficient to ensure (len+3)/3*4 < 2**31 */ 157 if (len > LIMIT_BEFORE_EXPANSION) { 158 BUFerr(BUF_F_BUF_MEM_GROW_CLEAN, ERR_R_MALLOC_FAILURE); 159 return 0; 160 } 161 n = (len + 3) / 3 * 4; 162 if (str->data == NULL) 163 ret = OPENSSL_malloc(n); 164 else 165 ret = OPENSSL_realloc_clean(str->data, str->max, n); 166 if (ret == NULL) { 167 BUFerr(BUF_F_BUF_MEM_GROW_CLEAN, ERR_R_MALLOC_FAILURE); 168 len = 0; 169 } else { 170 str->data = ret; 171 str->max = n; 172 memset(&str->data[str->length], 0, len - str->length); 173 str->length = len; 174 } 175 return (len); 176} 177