xref: /freebsd/crypto/openssl/doc/man3/BUF_MEM_new.pod (revision e47161e5f1f01ef300c6e7efdb9c92e3a6c497ff)
1=pod
2
3=head1 NAME
4
5BUF_MEM_new, BUF_MEM_new_ex, BUF_MEM_free, BUF_MEM_grow,
6BUF_MEM_grow_clean, BUF_reverse
7- simple character array structure
8
9=head1 SYNOPSIS
10
11 #include <openssl/buffer.h>
12
13 BUF_MEM *BUF_MEM_new(void);
14
15 BUF_MEM *BUF_MEM_new_ex(unsigned long flags);
16
17 void BUF_MEM_free(BUF_MEM *a);
18
19 int BUF_MEM_grow(BUF_MEM *str, int len);
20 size_t BUF_MEM_grow_clean(BUF_MEM *str, size_t len);
21
22 void BUF_reverse(unsigned char *out, const unsigned char *in, size_t size);
23
24=head1 DESCRIPTION
25
26The buffer library handles simple character arrays. Buffers are used for
27various purposes in the library, most notably memory BIOs.
28
29BUF_MEM_new() allocates a new buffer of zero size.
30
31BUF_MEM_new_ex() allocates a buffer with the specified flags.
32The flag B<BUF_MEM_FLAG_SECURE> specifies that the B<data> pointer
33should be allocated on the secure heap; see L<CRYPTO_secure_malloc(3)>.
34
35BUF_MEM_free() frees up an already existing buffer. The data is zeroed
36before freeing up in case the buffer contains sensitive data.
37If the argument is NULL, nothing is done.
38
39BUF_MEM_grow() changes the size of an already existing buffer to
40B<len>. Any data already in the buffer is preserved if it increases in
41size.
42
43BUF_MEM_grow_clean() is similar to BUF_MEM_grow() but it sets any free'd
44or additionally-allocated memory to zero.
45
46BUF_reverse() reverses B<size> bytes at B<in> into B<out>.  If B<in>
47is NULL, the array is reversed in-place.
48
49=head1 RETURN VALUES
50
51BUF_MEM_new() returns the buffer or NULL on error.
52
53BUF_MEM_free() has no return value.
54
55BUF_MEM_grow() and BUF_MEM_grow_clean() return
56zero on error or the new size (i.e., B<len>).
57
58=head1 SEE ALSO
59
60L<bio(7)>,
61L<CRYPTO_secure_malloc(3)>.
62
63=head1 HISTORY
64
65The BUF_MEM_new_ex() function was added in OpenSSL 1.1.0.
66
67=head1 COPYRIGHT
68
69Copyright 2000-2024 The OpenSSL Project Authors. All Rights Reserved.
70
71Licensed under the Apache License 2.0 (the "License").  You may not use
72this file except in compliance with the License.  You can obtain a copy
73in the file LICENSE in the source distribution or at
74L<https://www.openssl.org/source/license.html>.
75
76=cut
77