introduced new logging subsystem using bus:

passive listeners can register on the bus
  active listeners wait for signals actively
  multiplexing allows multiple listeners to receive debug signals
  a lot more...

src/charon/encoding/message.h

@@ -34,6 +34,11 @@
 #include <crypto/crypters/crypter.h>
 #include <crypto/signers/signer.h>
 
+/**
+ * printf() specifier for message
+ */
+#define MESSAGE_PRINTF_SPEC 'M'
+
 
 typedef struct message_t message_t;