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1/* $OpenBSD: buffer.c,v 1.29 2025/05/10 05:54:38 tb 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
65#include "err_local.h"
66
67/*
68 * LIMIT_BEFORE_EXPANSION is the maximum n such that (n + 3) / 3 * 4 < 2**31.
69 * That function is applied in several functions in this file and this limit
70 * ensures that the result fits in an int.
71 */
72#define LIMIT_BEFORE_EXPANSION 0x5ffffffc
73
74BUF_MEM *
75BUF_MEM_new(void)
76{
77 BUF_MEM *ret;
78
79 if ((ret = calloc(1, sizeof(BUF_MEM))) == NULL) {
80 BUFerror(ERR_R_MALLOC_FAILURE);
81 return (NULL);
82 }
83
84 return (ret);
85}
86LCRYPTO_ALIAS(BUF_MEM_new);
87
88void
89BUF_MEM_free(BUF_MEM *a)
90{
91 if (a == NULL)
92 return;
93
94 freezero(a->data, a->max);
95 free(a);
96}
97LCRYPTO_ALIAS(BUF_MEM_free);
98
99int
100BUF_MEM_grow(BUF_MEM *str, size_t len)
101{
102 return BUF_MEM_grow_clean(str, len);
103}
104LCRYPTO_ALIAS(BUF_MEM_grow);
105
106int
107BUF_MEM_grow_clean(BUF_MEM *str, size_t len)
108{
109 char *ret;
110 size_t n;
111
112 if (str->max >= len) {
113 if (str->length >= len)
114 memset(&str->data[len], 0, str->length - len);
115 str->length = len;
116 return (len);
117 }
118
119 if (len > LIMIT_BEFORE_EXPANSION) {
120 BUFerror(ERR_R_MALLOC_FAILURE);
121 return 0;
122 }
123
124 n = (len + 3) / 3 * 4;
125 if ((ret = recallocarray(str->data, str->max, n, 1)) == NULL) {
126 BUFerror(ERR_R_MALLOC_FAILURE);
127 return (0);
128 }
129 str->data = ret;
130 str->max = n;
131 str->length = len;
132
133 return (len);
134}
135LCRYPTO_ALIAS(BUF_MEM_grow_clean);
136
137void
138BUF_reverse(unsigned char *out, const unsigned char *in, size_t size)
139{
140 size_t i;
141
142 if (in) {
143 out += size - 1;
144 for (i = 0; i < size; i++)
145 *out-- = *in++;
146 } else {
147 unsigned char *q;
148 char c;
149 q = out + size - 1;
150 for (i = 0; i < size / 2; i++) {
151 c = *q;
152 *q-- = *out;
153 *out++ = c;
154 }
155 }
156}