1=pod
2
3=head1 NAME
4
5CRYPTO_memcmp - Constant time memory comparison
6
7=head1 SYNOPSIS
8
9 #include <openssl/crypto.h>
10
11 int CRYPTO_memcmp(const void *a, const void *b, size_t len);
12
13=head1 DESCRIPTION
14
15The CRYPTO_memcmp function compares the B<len> bytes pointed to by B<a> and B<b>
16for equality.
17It takes an amount of time dependent on B<len>, but independent of the
18contents of the memory regions pointed to by B<a> and B<b>.
19
20=head1 RETURN VALUES
21
22CRYPTO_memcmp() returns 0 if the memory regions are equal and non-zero
23otherwise.
24
25=head1 NOTES
26
27Unlike memcmp(2), this function cannot be used to order the two memory regions
28as the return value when they differ is undefined, other than being non-zero.
29
30=head1 COPYRIGHT
31
32Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
33
34Licensed under the Apache License 2.0 (the "License").  You may not use
35this file except in compliance with the License.  You can obtain a copy
36in the file LICENSE in the source distribution or at
37L<https://www.openssl.org/source/license.html>.
38
39=cut
40