debian man page for dsa_dup_dh

DSA_dup_DH(3SSL)						      OpenSSL							  DSA_dup_DH(3SSL)

NAME
       DSA_dup_DH - create a DH structure out of DSA structure

SYNOPSIS
	#include <openssl/dsa.h>

	DH * DSA_dup_DH(const DSA *r);

DESCRIPTION
       DSA_dup_DH() duplicates DSA parameters/keys as DH parameters/keys. q is lost during that conversion, but the resulting DH parameters
       contain its length.

RETURN VALUE
       DSA_dup_DH() returns the new DH structure, and NULL on error. The error codes can be obtained by ERR_get_error(3).

NOTE
       Be careful to avoid small subgroup attacks when using this.

SEE ALSO
       dh(3), dsa(3), ERR_get_error(3)

HISTORY
       DSA_dup_DH() was added in OpenSSL 0.9.4.

1.0.1e								    2013-02-11							  DSA_dup_DH(3SSL)