xref: /freebsd/crypto/openssl/doc/man3/BUF_MEM_new.pod (revision e17f5b1d307b7b8910d67883e57a9604305906d5)
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.
37
38BUF_MEM_grow() changes the size of an already existing buffer to
39B<len>. Any data already in the buffer is preserved if it increases in
40size.
41
42BUF_MEM_grow_clean() is similar to BUF_MEM_grow() but it sets any free'd
43or additionally-allocated memory to zero.
44
45BUF_reverse() reverses B<size> bytes at B<in> into B<out>.  If B<in>
46is NULL, the array is reversed in-place.
47
48=head1 RETURN VALUES
49
50BUF_MEM_new() returns the buffer or NULL on error.
51
52BUF_MEM_free() has no return value.
53
54BUF_MEM_grow() and BUF_MEM_grow_clean() return
55zero on error or the new size (i.e., B<len>).
56
57=head1 SEE ALSO
58
59L<bio(7)>,
60L<CRYPTO_secure_malloc(3)>.
61
62=head1 HISTORY
63
64The BUF_MEM_new_ex() function was added in OpenSSL 1.1.0.
65
66=head1 COPYRIGHT
67
68Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
69
70Licensed under the OpenSSL license (the "License").  You may not use
71this file except in compliance with the License.  You can obtain a copy
72in the file LICENSE in the source distribution or at
73L<https://www.openssl.org/source/license.html>.
74
75=cut
76