1=pod
2
3=head1 NAME
4
5RSA_size, RSA_bits, RSA_security_bits - get RSA modulus size or security bits
6
7=head1 SYNOPSIS
8
9 #include <openssl/rsa.h>
10
11 int RSA_bits(const RSA *rsa);
12
13Deprecated since OpenSSL 3.0, can be hidden entirely by defining
14B<OPENSSL_API_COMPAT> with a suitable version value, see
15L<openssl_user_macros(7)>:
16
17 int RSA_size(const RSA *rsa);
18
19 int RSA_security_bits(const RSA *rsa);
20
21=head1 DESCRIPTION
22
23RSA_bits() returns the number of significant bits.
24
25B<rsa> and B<rsa-E<gt>n> must not be B<NULL>.
26
27The remaining functions described on this page are deprecated.
28Applications should instead use L<EVP_PKEY_get_size(3)>, L<EVP_PKEY_get_bits(3)>
29and L<EVP_PKEY_get_security_bits(3)>.
30
31RSA_size() returns the RSA modulus size in bytes. It can be used to
32determine how much memory must be allocated for an RSA encrypted
33value.
34
35RSA_security_bits() returns the number of security bits of the given B<rsa>
36key. See L<BN_security_bits(3)>.
37
38=head1 RETURN VALUES
39
40RSA_bits() returns the number of bits in the key.
41
42RSA_size() returns the size of modulus in bytes.
43
44RSA_security_bits() returns the number of security bits.
45
46=head1 SEE ALSO
47
48L<BN_num_bits(3)>
49
50=head1 HISTORY
51
52The RSA_size() and RSA_security_bits() functions were deprecated in OpenSSL 3.0.
53
54The RSA_bits() function was added in OpenSSL 1.1.0.
55
56=head1 COPYRIGHT
57
58Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
59
60Licensed under the Apache License 2.0 (the "License").  You may not use
61this file except in compliance with the License.  You can obtain a copy
62in the file LICENSE in the source distribution or at
63L<https://www.openssl.org/source/license.html>.
64
65=cut
66