NAME

       DH_size, DH_bits, DH_security_bits - get Diffie-Hellman prime size and security bits

SYNOPSIS

        #include <openssl/dh.h>

        int DH_size(const DH *dh);

        int DH_bits(const DH *dh);

        int DH_security_bits(const DH *dh);

DESCRIPTION

       DH_size() returns the Diffie-Hellman prime size in bytes. It can be used to determine how much memory
       must be allocated for the shared secret computed by DH_compute_key(3).

       DH_bits() returns the number of significant bits.

       dh and dh->p must not be NULL.

       DH_security_bits() returns the number of security bits of the given dh key. See BN_security_bits(3).

RETURN VALUES

       DH_size() returns the prime size of Diffie-Hellman in bytes.

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

       DH_security_bits() returns the number of security bits.

SEE ALSO

       DH_new(3), DH_generate_key(3), BN_num_bits(3)

HISTORY

       The DH_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>.

1.1.1f                                             2025-02-05                                      DH_SIZE(3SSL)