1 /* $OpenBSD: buffer.c,v 1.20 2014/07/10 13:58:22 jsing Exp $ */ 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 <stdlib.h> 61 #include <string.h> 62 63 #include <openssl/buffer.h> 64 #include <openssl/err.h> 65 66 /* LIMIT_BEFORE_EXPANSION is the maximum n such that (n+3)/3*4 < 2**31. That 67 * function is applied in several functions in this file and this limit ensures 68 * that the result fits in an int. */ 69 #define LIMIT_BEFORE_EXPANSION 0x5ffffffc 70 71 BUF_MEM * 72 BUF_MEM_new(void) 73 { 74 BUF_MEM *ret; 75 76 ret = malloc(sizeof(BUF_MEM)); 77 if (ret == NULL) { 78 BUFerr(BUF_F_BUF_MEM_NEW, ERR_R_MALLOC_FAILURE); 79 return (NULL); 80 } 81 ret->length = 0; 82 ret->max = 0; 83 ret->data = NULL; 84 return (ret); 85 } 86 87 void 88 BUF_MEM_free(BUF_MEM *a) 89 { 90 if (a == NULL) 91 return; 92 93 if (a->data != NULL) { 94 explicit_bzero(a->data, a->max); 95 free(a->data); 96 } 97 free(a); 98 } 99 100 int 101 BUF_MEM_grow(BUF_MEM *str, size_t len) 102 { 103 char *ret; 104 size_t n; 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 ret = realloc(str->data, n); 122 if (ret == NULL) { 123 BUFerr(BUF_F_BUF_MEM_GROW, ERR_R_MALLOC_FAILURE); 124 len = 0; 125 } else { 126 str->data = ret; 127 str->max = n; 128 memset(&str->data[str->length], 0, len - str->length); 129 str->length = len; 130 } 131 return (len); 132 } 133 134 int 135 BUF_MEM_grow_clean(BUF_MEM *str, size_t len) 136 { 137 char *ret; 138 size_t n; 139 140 if (str->length >= len) { 141 memset(&str->data[len], 0, str->length - len); 142 str->length = len; 143 return (len); 144 } 145 if (str->max >= len) { 146 memset(&str->data[str->length], 0, len - str->length); 147 str->length = len; 148 return (len); 149 } 150 /* This limit is sufficient to ensure (len+3)/3*4 < 2**31 */ 151 if (len > LIMIT_BEFORE_EXPANSION) { 152 BUFerr(BUF_F_BUF_MEM_GROW_CLEAN, ERR_R_MALLOC_FAILURE); 153 return 0; 154 } 155 n = (len + 3) / 3 * 4; 156 ret = malloc(n); 157 /* we're not shrinking - that case returns above */ 158 if ((ret != NULL) && (str->data != NULL)) { 159 memcpy(ret, str->data, str->max); 160 explicit_bzero(str->data, str->max); 161 free(str->data); 162 } 163 if (ret == NULL) { 164 BUFerr(BUF_F_BUF_MEM_GROW_CLEAN, ERR_R_MALLOC_FAILURE); 165 len = 0; 166 } else { 167 str->data = ret; 168 str->max = n; 169 memset(&str->data[str->length], 0, len - str->length); 170 str->length = len; 171 } 172 return (len); 173 } 174 175 void 176 BUF_reverse(unsigned char *out, const unsigned char *in, size_t size) 177 { 178 size_t i; 179 180 if (in) { 181 out += size - 1; 182 for (i = 0; i < size; i++) 183 *out-- = *in++; 184 } else { 185 unsigned char *q; 186 char c; 187 q = out + size - 1; 188 for (i = 0; i < size / 2; i++) { 189 c = *q; 190 *q-- = *out; 191 *out++ = c; 192 } 193 } 194 } 195