DSA_new() allocates and initializes a DSA structure. It is equivalent to
calling DSA_new_method(NULL).
DSA_free() frees the DSA structure and its components. The values are
erased before the memory is returned to the system.
RETURN VALUES
If the allocation fails, DSA_new() returns NULL and sets an error
code that can be obtained by
ERR_get_error(3). Otherwise it returns a pointer
to the newly allocated structure.
