Rename diffie_hellman_t to key_exchange_t and change the interface etc.

This makes it more generic so we can use it for QSKE methods.

src/libcharon/plugins/ha/ha_child.c

@@ -51,7 +51,7 @@ struct private_ha_child_t {
 
 METHOD(listener_t, child_keys, bool,
 	private_ha_child_t *this, ike_sa_t *ike_sa, child_sa_t *child_sa,
-	bool initiator, diffie_hellman_t *dh, chunk_t nonce_i, chunk_t nonce_r)
+	bool initiator, key_exchange_t *dh, chunk_t nonce_i, chunk_t nonce_r)
 {
 	ha_message_t *m;
 	chunk_t secret;
@@ -92,7 +92,7 @@ METHOD(listener_t, child_keys, bool,
 	{
 		m->add_attribute(m, HA_ALG_INTEG, alg);
 	}
-	if (proposal->get_algorithm(proposal, DIFFIE_HELLMAN_GROUP, &alg, NULL))
+	if (proposal->get_algorithm(proposal, KEY_EXCHANGE_METHOD, &alg, NULL))
 	{
 		m->add_attribute(m, HA_ALG_DH, alg);
 	}