OpenSSL

Cryptography and SSL/TLS Toolkit

DH_size

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

DH_bits() was added in OpenSSL 1.1.0.

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

Licensed under the Apache License 2.0 (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.