openssl/doc/man3/RSA_size.pod

=pod

=head1 NAME

RSA_size, RSA_bits, RSA_security_bits - get RSA modulus size or security bits

=head1 SYNOPSIS

 #include <openssl/rsa.h>

 int RSA_size(const RSA *rsa);

 int RSA_bits(const RSA *rsa);

 int RSA_security_bits(const RSA *rsa)

=head1 DESCRIPTION

RSA_size() returns the RSA modulus size in bytes. It can be used to
determine how much memory must be allocated for an RSA encrypted
value.

RSA_bits() returns the number of significant bits.

B<rsa> and B<rsa-E<gt>n> must not be B<NULL>.

RSA_security_bits() returns the number of security bits of the given B<rsa>
key. See L<BN_security_bits(3)>.

=head1 RETURN VALUES

RSA_size() returns the size of modulus in bytes.

DSA_bits() returns the number of bits in the key.

RSA_security_bits() returns the number of security bits.

=head1 SEE ALSO

L<BN_num_bits(3)>

=head1 HISTORY

RSA_bits() was added in OpenSSL 1.1.0.

=head1 COPYRIGHT

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

Licensed under the OpenSSL license (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>.

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