Add _init() and _free() for cipher modules

include/polarssl/blowfish.h

@@ -70,6 +70,20 @@ typedef struct
 }
 blowfish_context;
 
+/**
+ * \brief          Initialize Blowfish context
+ *
+ * \param ctx      Blowfish context to be initialized
+ */
+void blowfish_init( blowfish_context *ctx );
+
+/**
+ * \brief          Clear Blowfish context
+ *
+ * \param ctx      Blowfish context to be cleared
+ */
+void blowfish_free( blowfish_context *ctx );
+
 /**
  * \brief          Blowfish key schedule
  *