man DSA_size () - get DSA signature size
NAME
DSA_size - get DSA signature size
SYNOPSIS
#include <openssl/dsa.h>
int DSA_size(const DSA *dsa);
DESCRIPTION
This function returns the size of an ASN.1 encoded DSA signature in bytes. It can be used to determine how much memory must be allocated for a DSA signature.
dsa->q must not be NULL.
RETURN VALUE
The size in bytes.
SEE ALSO
HISTORY
DSA_size() is available in all versions of SSLeay and OpenSSL.