xref: /freebsd/crypto/openssl/doc/man3/DH_size.pod (revision e71b70530d95c4f34d8bdbd78d1242df1ba4a945)
1=pod
2
3=head1 NAME
4
5DH_size, DH_bits, DH_security_bits - get Diffie-Hellman prime size and
6security bits
7
8=head1 SYNOPSIS
9
10 #include <openssl/dh.h>
11
12 int DH_size(const DH *dh);
13
14 int DH_bits(const DH *dh);
15
16 int DH_security_bits(const DH *dh);
17
18=head1 DESCRIPTION
19
20DH_size() returns the Diffie-Hellman prime size in bytes. It can be used
21to determine how much memory must be allocated for the shared secret
22computed by L<DH_compute_key(3)>.
23
24DH_bits() returns the number of significant bits.
25
26B<dh> and B<dh-E<gt>p> must not be B<NULL>.
27
28DH_security_bits() returns the number of security bits of the given B<dh>
29key. See L<BN_security_bits(3)>.
30
31=head1 RETURN VALUES
32
33DH_size() returns the prime size of Diffie-Hellman in bytes.
34
35DH_bits() returns the number of bits in the key.
36
37DH_security_bits() returns the number of security bits.
38
39=head1 SEE ALSO
40
41L<DH_new(3)>, L<DH_generate_key(3)>,
42L<BN_num_bits(3)>
43
44=head1 HISTORY
45
46DH_bits() was added in OpenSSL 1.1.0.
47
48=head1 COPYRIGHT
49
50Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
51
52Licensed under the OpenSSL license (the "License").  You may not use
53this file except in compliance with the License.  You can obtain a copy
54in the file LICENSE in the source distribution or at
55L<https://www.openssl.org/source/license.html>.
56
57=cut
58