[thirdparty/openssl.git] / doc / man3 / BUF_MEM_new.pod

=pod

=head1 NAME

BUF_MEM_new, BUF_MEM_new_ex, BUF_MEM_free, BUF_MEM_grow,
BUF_MEM_grow_clean, BUF_reverse
- simple character array structure

=head1 SYNOPSIS

 #include <openssl/buffer.h>

 BUF_MEM *BUF_MEM_new(void);

 BUF_MEM *BUF_MEM_new_ex(unsigned long flags);

 void BUF_MEM_free(BUF_MEM *a);

 int BUF_MEM_grow(BUF_MEM *str, int len);
 size_t BUF_MEM_grow_clean(BUF_MEM *str, size_t len);

 void BUF_reverse(unsigned char *out, const unsigned char *in, size_t size);

=head1 DESCRIPTION

The buffer library handles simple character arrays. Buffers are used for
various purposes in the library, most notably memory BIOs.

BUF_MEM_new() allocates a new buffer of zero size.

BUF_MEM_new_ex() allocates a buffer with the specified flags.
The flag B<BUF_MEM_FLAG_SECURE> specifies that the B<data> pointer
should be allocated on the secure heap; see L<CRYPTO_secure_malloc(3)>.

BUF_MEM_free() frees up an already existing buffer. The data is zeroed
before freeing up in case the buffer contains sensitive data.

BUF_MEM_grow() changes the size of an already existing buffer to
B<len>. Any data already in the buffer is preserved if it increases in
size.

BUF_MEM_grow_clean() is similar to BUF_MEM_grow() but it sets any free'd
or additionally-allocated memory to zero.

BUF_reverse() reverses B<size> bytes at B<in> into B<out>.  If B<in>
is NULL, the array is reversed in-place.

=head1 RETURN VALUES

BUF_MEM_new() returns the buffer or NULL on error.

BUF_MEM_free() has no return value.

BUF_MEM_grow() and BUF_MEM_grow_clean() return
zero on error or the new size (i.e., B<len>).

=head1 SEE ALSO

L<bio(7)>,
L<CRYPTO_secure_malloc(3)>.

=head1 HISTORY

The BUF_MEM_new_ex() function was added in OpenSSL 1.1.0.

=head1 COPYRIGHT

Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License").  You may not use
this file except in compliance with the License.  You can obtain a copy
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.

=cut
Commit	Line	Data
74235cc9 UM	1	=pod
	2
	3	=head1 NAME
	4
6061f80b	5	BUF_MEM_new, BUF_MEM_new_ex, BUF_MEM_free, BUF_MEM_grow,
c952780c RS	6	BUF_MEM_grow_clean, BUF_reverse
c952780c RS	7	- simple character array structure
58e3457a	8
74235cc9 UM	9	=head1 SYNOPSIS
	10
	11	#include <openssl/buffer.h>
	12
	13	BUF_MEM *BUF_MEM_new(void);
	14
58e3457a	15	BUF_MEM *BUF_MEM_new_ex(unsigned long flags);
74924dcb	16
c952780c	17	void BUF_MEM_free(BUF_MEM *a);
74235cc9	18
c952780c RS	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);
74235cc9	23
58e3457a EK	24	=head1 DESCRIPTION
	25
	26	The buffer library handles simple character arrays. Buffers are used for
	27	various purposes in the library, most notably memory BIOs.
74235cc9 UM	28
	29	BUF_MEM_new() allocates a new buffer of zero size.
	30
74924dcb RS	31	BUF_MEM_new_ex() allocates a buffer with the specified flags.
	32	The flag B<BUF_MEM_FLAG_SECURE> specifies that the B<data> pointer
	33	should be allocated on the secure heap; see L<CRYPTO_secure_malloc(3)>.
	34
74235cc9 UM	35	BUF_MEM_free() frees up an already existing buffer. The data is zeroed
	36	before freeing up in case the buffer contains sensitive data.
	37
	38	BUF_MEM_grow() changes the size of an already existing buffer to
	39	B<len>. Any data already in the buffer is preserved if it increases in
	40	size.
	41
c952780c RS	42	BUF_MEM_grow_clean() is similar to BUF_MEM_grow() but it sets any free'd
	43	or additionally-allocated memory to zero.
	44
498180de	45	BUF_reverse() reverses B<size> bytes at B<in> into B<out>. If B<in>
c952780c RS	46	is NULL, the array is reversed in-place.
c952780c RS	47
74235cc9 UM	48	=head1 RETURN VALUES
	49
	50	BUF_MEM_new() returns the buffer or NULL on error.
	51
	52	BUF_MEM_free() has no return value.
	53
c952780c RS	54	BUF_MEM_grow() and BUF_MEM_grow_clean() return
c952780c RS	55	zero on error or the new size (i.e., B<len>).
74235cc9 UM	56
	57	=head1 SEE ALSO
	58
b97fdb57	59	L<bio(7)>,
74924dcb	60	L<CRYPTO_secure_malloc(3)>.
74235cc9 UM	61
	62	=head1 HISTORY
	63
fc5ecadd	64	The BUF_MEM_new_ex() function was added in OpenSSL 1.1.0.
74924dcb	65
e2f92610 RS	66	=head1 COPYRIGHT
e2f92610 RS	67
fd38836b	68	Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
e2f92610	69
4746f25a	70	Licensed under the Apache License 2.0 (the "License"). You may not use
e2f92610 RS	71	this file except in compliance with the License. You can obtain a copy
	72	in the file LICENSE in the source distribution or at
	73	L<https://www.openssl.org/source/license.html>.
	74
	75	=cut