From 9f337e3cae654fb95a2a1563f7190283fa80bd76 Mon Sep 17 00:00:00 2001
From: Patrick Fallberg <patrick@fallberg.net>
Date: Thu, 5 Feb 2015 22:49:05 +0100
Subject: [PATCH] Message header updates for signing support

One bit in the protocol version field is converted to a sign
indicator. '1' means the message carries a signature in the
unused part of the payload data buffer.

Three new internal message types have been defined:

 * I_REQUEST_SIGNING    carries a boolean and is used to exchange
                        signing requirement information between
                        nodes.
                        If the I_REQUEST_SIGNING carries 'true'
                        the receiver is informed that the sender
                        require properly signed messages in order
                        to be able to accept the messages.
 * I_GET_NONCE          is passed from sender to a receiver that
                        require signing tellig it to submit a
                        cryptographic 'nonce' that the sender needs
                        in order to be able to sign the message it
                        intend to send. The I_GET_NONCE carries no
                        payload.
 * I_GET_NONCE_RESPONSE is sent by the receiver of a signed
                        message in response to I_GET_NONCE.
                        The first byte of the payload is a signing
                        identifier informing the sender of the
                        signed message about the type of signature
                        the receiver is expecting.
---
 libraries/MySensors/MyMessage.h | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/libraries/MySensors/MyMessage.h b/libraries/MySensors/MyMessage.h
index a46fbee..fcc0540 100644
--- a/libraries/MySensors/MyMessage.h
+++ b/libraries/MySensors/MyMessage.h
@@ -47,7 +47,7 @@ typedef enum {
 	I_BATTERY_LEVEL, I_TIME, I_VERSION, I_ID_REQUEST, I_ID_RESPONSE,
 	I_INCLUSION_MODE, I_CONFIG, I_FIND_PARENT, I_FIND_PARENT_RESPONSE,
 	I_LOG_MESSAGE, I_CHILDREN, I_SKETCH_NAME, I_SKETCH_VERSION,
-	I_REBOOT, I_GATEWAY_READY
+	I_REBOOT, I_GATEWAY_READY, I_REQUEST_SIGNING, I_GET_NONCE, I_GET_NONCE_RESPONSE
 } mysensor_internal;
 
 // Type of sensor  (for presentation message)
@@ -84,8 +84,11 @@ typedef enum {
 #define BF_SET(y, x, start, len)    ( y= ((y) &~ BF_MASK(start, len)) | BF_PREP(x, start, len) )
 
 // Getters/setters for special bit fields in header
-#define mSetVersion(_msg,_version) BF_SET(_msg.version_length, _version, 0, 3)
-#define mGetVersion(_msg) BF_GET(_msg.version_length, 0, 3)
+#define mSetVersion(_msg,_version) BF_SET(_msg.version_length, _version, 0, 2)
+#define mGetVersion(_msg) BF_GET(_msg.version_length, 0, 2)
+
+#define mSetSigned(_msg,_signed) BF_SET(_msg.version_length, _signed, 2, 1)
+#define mGetSigned(_msg) BF_GET(_msg.version_length, 2, 1)
 
 #define mSetLength(_msg,_length) BF_SET(_msg.version_length, _length, 3, 5)
 #define mGetLength(_msg) BF_GET(_msg.version_length, 3, 5)
@@ -179,7 +182,8 @@ struct
 	uint8_t sender;          	 // 8 bit - Id of sender node (origin)
 	uint8_t destination;     	 // 8 bit - Id of destination node
 
-	uint8_t version_length;      // 3 bit - Protocol version
+	uint8_t version_length;		 // 2 bit - Protocol version
+			                     // 1 bit - Signed flag
 			                     // 5 bit - Length of payload
 	uint8_t command_ack_payload; // 3 bit - Command type
 	                             // 1 bit - Request an ack - Indicator that receiver should send an ack back.