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/* 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 ensures
65 * that the result fits in an int. */
66#define LIMIT_BEFORE_EXPANSION 0x5ffffffc
67
68BUF_MEM *BUF_MEM_new(void)
69	{
70	BUF_MEM *ret;
71
72	ret=OPENSSL_malloc(sizeof(BUF_MEM));
73	if (ret == NULL)
74		{
75		BUFerr(BUF_F_BUF_MEM_NEW,ERR_R_MALLOC_FAILURE);
76		return(NULL);
77		}
78	ret->length=0;
79	ret->max=0;
80	ret->data=NULL;
81	return(ret);
82	}
83
84void BUF_MEM_free(BUF_MEM *a)
85	{
86	if(a == NULL)
87	    return;
88
89	if (a->data != NULL)
90		{
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, size_t len)
98	{
99	char *ret;
100	size_t n;
101
102	if (str->length >= len)
103		{
104		str->length=len;
105		return(len);
106		}
107	if (str->max >= len)
108		{
109		memset(&str->data[str->length],0,len-str->length);
110		str->length=len;
111		return(len);
112		}
113	/* This limit is sufficient to ensure (len+3)/3*4 < 2**31 */
114	if (len > LIMIT_BEFORE_EXPANSION)
115		{
116		BUFerr(BUF_F_BUF_MEM_GROW,ERR_R_MALLOC_FAILURE);
117		return 0;
118		}
119	n=(len+3)/3*4;
120	if (str->data == NULL)
121		ret=OPENSSL_malloc(n);
122	else
123		ret=OPENSSL_realloc(str->data,n);
124	if (ret == NULL)
125		{
126		BUFerr(BUF_F_BUF_MEM_GROW,ERR_R_MALLOC_FAILURE);
127		len=0;
128		}
129	else
130		{
131		str->data=ret;
132		str->max=n;
133		memset(&str->data[str->length],0,len-str->length);
134		str->length=len;
135		}
136	return(len);
137	}
138
139int BUF_MEM_grow_clean(BUF_MEM *str, size_t len)
140	{
141	char *ret;
142	size_t n;
143
144	if (str->length >= len)
145		{
146		memset(&str->data[len],0,str->length-len);
147		str->length=len;
148		return(len);
149		}
150	if (str->max >= len)
151		{
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		{
159		BUFerr(BUF_F_BUF_MEM_GROW_CLEAN,ERR_R_MALLOC_FAILURE);
160		return 0;
161		}
162	n=(len+3)/3*4;
163	if (str->data == NULL)
164		ret=OPENSSL_malloc(n);
165	else
166		ret=OPENSSL_realloc_clean(str->data,str->max,n);
167	if (ret == NULL)
168		{
169		BUFerr(BUF_F_BUF_MEM_GROW_CLEAN,ERR_R_MALLOC_FAILURE);
170		len=0;
171		}
172	else
173		{
174		str->data=ret;
175		str->max=n;
176		memset(&str->data[str->length],0,len-str->length);
177		str->length=len;
178		}
179	return(len);
180	}
181
182void BUF_reverse(unsigned char *out, const unsigned char *in, size_t size)
183	{
184	size_t i;
185	if (in)
186		{
187		out += size - 1;
188		for (i = 0; i < size; i++)
189			*out-- = *in++;
190		}
191	else
192		{
193		unsigned char *q;
194		char c;
195		q = out + size - 1;
196		for (i = 0; i < size/2; i++)
197			{
198			c = *q;
199			*q-- = *out;
200			*out++ = c;
201			}
202		}
203	}
204