- NAME
- SYNOPSIS
- DESCRIPTION
- RETURN VALUES
- SEE ALSO
- HISTORY
- COPYRIGHT

# 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.