DH_SIZE

Section: OpenSSL (3)
Updated: 2021-03-26
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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.

HISTORY

The DH_bits() function was added in OpenSSL 1.1.0.

COPYRIGHT

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>.