RSA_size(3) - phpMan

RSA_SIZE(3)                         OpenSSL                        RSA_SIZE(3)
NAME
       RSA_size, RSA_bits, RSA_security_bits - get RSA modulus size or
       security bits
SYNOPSIS
        #include <openssl/rsa.h>
        int RSA_size(const RSA *rsa);
        int RSA_bits(const RSA *rsa);
        int RSA_security_bits(const RSA *rsa)
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.
       rsa and rsa->n must not be NULL.
       RSA_security_bits() returns the number of security bits of the given
       rsa key. See BN_security_bits(3).
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.
SEE ALSO
       BN_num_bits(3)
HISTORY
       The RSA_bits() function was added in OpenSSL 1.1.0.
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
       <https://www.openssl.org/source/license.html>;.
1.1.1k                            2021-03-25                       RSA_SIZE(3)