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, int len)
98	{
99	char *ret;
100	unsigned int n;
101
102	if (len < 0)
103		{
104		BUFerr(BUF_F_BUF_MEM_GROW,ERR_R_MALLOC_FAILURE);
105		return 0;
106		}
107	if (str->length >= len)
108		{
109		str->length=len;
110		return(len);
111		}
112	if (str->max >= len)
113		{
114		memset(&str->data[str->length],0,len-str->length);
115		str->length=len;
116		return(len);
117		}
118	/* This limit is sufficient to ensure (len+3)/3*4 < 2**31 */
119	if (len > LIMIT_BEFORE_EXPANSION)
120		{
121		BUFerr(BUF_F_BUF_MEM_GROW,ERR_R_MALLOC_FAILURE);
122		return 0;
123		}
124	n=(len+3)/3*4;
125	if (str->data == NULL)
126		ret=OPENSSL_malloc(n);
127	else
128		ret=OPENSSL_realloc(str->data,n);
129	if (ret == NULL)
130		{
131		BUFerr(BUF_F_BUF_MEM_GROW,ERR_R_MALLOC_FAILURE);
132		len=0;
133		}
134	else
135		{
136		str->data=ret;
137		str->max=n;
138		memset(&str->data[str->length],0,len-str->length);
139		str->length=len;
140		}
141	return(len);
142	}
143
144int BUF_MEM_grow_clean(BUF_MEM *str, int len)
145	{
146	char *ret;
147	unsigned int n;
148
149	if (len < 0)
150		{
151		BUFerr(BUF_F_BUF_MEM_GROW_CLEAN,ERR_R_MALLOC_FAILURE);
152		return 0;
153		}
154	if (str->length >= len)
155		{
156		memset(&str->data[len],0,str->length-len);
157		str->length=len;
158		return(len);
159		}
160	if (str->max >= len)
161		{
162		memset(&str->data[str->length],0,len-str->length);
163		str->length=len;
164		return(len);
165		}
166	/* This limit is sufficient to ensure (len+3)/3*4 < 2**31 */
167	if (len > LIMIT_BEFORE_EXPANSION)
168		{
169		BUFerr(BUF_F_BUF_MEM_GROW_CLEAN,ERR_R_MALLOC_FAILURE);
170		return 0;
171		}
172	n=(len+3)/3*4;
173	if (str->data == NULL)
174		ret=OPENSSL_malloc(n);
175	else
176		ret=OPENSSL_realloc_clean(str->data,str->max,n);
177	if (ret == NULL)
178		{
179		BUFerr(BUF_F_BUF_MEM_GROW_CLEAN,ERR_R_MALLOC_FAILURE);
180		len=0;
181		}
182	else
183		{
184		str->data=ret;
185		str->max=n;
186		memset(&str->data[str->length],0,len-str->length);
187		str->length=len;
188		}
189	return(len);
190	}
191