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/libstrongswan/plugins/openssl/openssl_diffie_hellman.h

@@ -32,20 +32,20 @@ typedef struct openssl_diffie_hellman_t openssl_diffie_hellman_t;
 struct openssl_diffie_hellman_t {
 
 	/**
-	 * Implements diffie_hellman_t interface.
+	 * Implements key_exchange_t interface.
 	 */
-	diffie_hellman_t dh;
+	key_exchange_t ke;
 };
 
 /**
  * Creates a new openssl_diffie_hellman_t object.
  *
- * @param group			Diffie Hellman group number to use
+ * @param group			Diffie-Hellman group number to use
  * @param ...			expects generator and prime as chunk_t if MODP_CUSTOM
  * @return				openssl_diffie_hellman_t object, NULL if not supported
  */
 openssl_diffie_hellman_t *openssl_diffie_hellman_create(
-											diffie_hellman_group_t group, ...);
+											key_exchange_method_t group, ...);
 
 #endif /** OPENSSL_DIFFIE_HELLMAN_H_ @}*/