From 3bf9184670583f695f4062d402f5a088079526da Mon Sep 17 00:00:00 2001
From: Patrick Fallberg <patrick@fallberg.net>
Date: Sun, 3 Jan 2016 20:51:40 +0100
Subject: [PATCH] Removed signing identifier from nonces

It serves no practical use to have signing identifier in nonces
as nonces are architecture independent.

Fixes #318
---
 libraries/MySensors/core/MySigning.cpp             | 13 ++++++-------
 libraries/MySensors/core/MySigningAtsha204.cpp     | 10 +---------
 libraries/MySensors/core/MySigningAtsha204Soft.cpp | 10 +---------
 3 files changed, 8 insertions(+), 25 deletions(-)

diff --git a/libraries/MySensors/core/MySigning.cpp b/libraries/MySensors/core/MySigning.cpp
index 2d0225c..1202474 100644
--- a/libraries/MySensors/core/MySigning.cpp
+++ b/libraries/MySensors/core/MySigning.cpp
@@ -59,14 +59,14 @@ enum { SIGN_WAITING_FOR_NONCE = 0, SIGN_OK = 1 };
 #if defined(MY_SIGNING_SOFT)
 extern bool signerAtsha204SoftCheckTimer(void);
 extern bool signerAtsha204SoftGetNonce(MyMessage &msg);
-extern bool signerAtsha204SoftPutNonce(MyMessage &msg);
+extern void signerAtsha204SoftPutNonce(MyMessage &msg);
 extern bool signerAtsha204SoftVerifyMsg(MyMessage &msg);
 extern bool signerAtsha204SoftSignMsg(MyMessage &msg);
 #endif
 #if defined(MY_SIGNING_ATSHA204)
 extern bool signerAtsha204CheckTimer(void);
 extern bool signerAtsha204GetNonce(MyMessage &msg);
-extern bool signerAtsha204PutNonce(MyMessage &msg);
+extern void signerAtsha204PutNonce(MyMessage &msg);
 extern bool signerAtsha204VerifyMsg(MyMessage &msg);
 extern bool signerAtsha204SignMsg(MyMessage &msg);
 #endif
@@ -240,17 +240,16 @@ bool signerProcessInternal(MyMessage &msg) {
 				return true; // No need to further process I_NONCE_RESPONSE
 			}
 #if defined(MY_SIGNING_SOFT)
-			if (!signerAtsha204SoftPutNonce(msg)) {
+			signerAtsha204SoftPutNonce(msg);
 #endif
 #if defined(MY_SIGNING_ATSHA204)
-			if (!signerAtsha204PutNonce(msg)) {
+			signerAtsha204PutNonce(msg);
 #endif
-				SIGN_DEBUG(PSTR("Failed to store nonce to signing backend!\n"));
 #if defined(MY_SIGNING_SOFT)
-			} else if (!signerAtsha204SoftSignMsg(_msgSign)) {
+			if (!signerAtsha204SoftSignMsg(_msgSign)) {
 #endif
 #if defined(MY_SIGNING_ATSHA204)
-			} else if (!signerAtsha204SignMsg(_msgSign)) {
+			if (!signerAtsha204SignMsg(_msgSign)) {
 #endif
 				SIGN_DEBUG(PSTR("Failed to sign message!\n"));
 			} else {
diff --git a/libraries/MySensors/core/MySigningAtsha204.cpp b/libraries/MySensors/core/MySigningAtsha204.cpp
index b5ac3ca..ce78678 100644
--- a/libraries/MySensors/core/MySigningAtsha204.cpp
+++ b/libraries/MySensors/core/MySigningAtsha204.cpp
@@ -117,9 +117,6 @@ bool signerAtsha204GetNonce(MyMessage &msg) {
 	// We set the part of the 32-byte nonce that does not fit into a message to 0xAA
 	memset(&_signing_current_nonce[MAX_PAYLOAD], 0xAA, sizeof(_signing_current_nonce)-MAX_PAYLOAD);
 
-	// Replace the first byte in the nonce with our signing identifier
-	_signing_current_nonce[0] = SIGNING_IDENTIFIER;
-
 	// Transfer the first part of the nonce to the message
 	msg.set(_signing_current_nonce, MAX_PAYLOAD);
 	_signing_verification_ongoing = true;
@@ -131,17 +128,12 @@ bool signerAtsha204GetNonce(MyMessage &msg) {
 	return true;
 }
 
-bool signerAtsha204PutNonce(MyMessage &msg) {
+void signerAtsha204PutNonce(MyMessage &msg) {
 	DEBUG_SIGNING_PRINTBUF(F("Signing backend: ATSHA204"), NULL, 0);
-	if (((uint8_t*)msg.getCustom())[0] != SIGNING_IDENTIFIER) {
-		DEBUG_SIGNING_PRINTBUF(F("Incorrect signing identifier"), NULL, 0);
-		return false; 
-	}
 
 	memcpy(_signing_current_nonce, (uint8_t*)msg.getCustom(), MAX_PAYLOAD);
 	// We set the part of the 32-byte nonce that does not fit into a message to 0xAA
 	memset(&_signing_current_nonce[MAX_PAYLOAD], 0xAA, sizeof(_signing_current_nonce)-MAX_PAYLOAD);
-	return true;
 }
 
 bool signerAtsha204SignMsg(MyMessage &msg) {
diff --git a/libraries/MySensors/core/MySigningAtsha204Soft.cpp b/libraries/MySensors/core/MySigningAtsha204Soft.cpp
index 2940d09..2b89fac 100644
--- a/libraries/MySensors/core/MySigningAtsha204Soft.cpp
+++ b/libraries/MySensors/core/MySigningAtsha204Soft.cpp
@@ -117,9 +117,6 @@ bool signerAtsha204SoftGetNonce(MyMessage &msg) {
 	// We set the part of the 32-byte nonce that does not fit into a message to 0xAA
 	memset(&_signing_current_nonce[MAX_PAYLOAD], 0xAA, sizeof(_signing_current_nonce)-MAX_PAYLOAD);
 
-	// Replace the first byte in the nonce with our signing identifier
-	_signing_current_nonce[0] = SIGNING_IDENTIFIER;
-	
 	// Transfer the first part of the nonce to the message
 	msg.set(_signing_current_nonce, MAX_PAYLOAD);
 	_signing_verification_ongoing = true;
@@ -131,17 +128,12 @@ bool signerAtsha204SoftGetNonce(MyMessage &msg) {
 	return true;
 }
 
-bool signerAtsha204SoftPutNonce(MyMessage &msg) {
+void signerAtsha204SoftPutNonce(MyMessage &msg) {
 	DEBUG_SIGNING_PRINTBUF(F("Signing backend: ATSHA204Soft"), NULL, 0);
-	if (((uint8_t*)msg.getCustom())[0] != SIGNING_IDENTIFIER) {
-		DEBUG_SIGNING_PRINTBUF(F("Incorrect signing identifier"), NULL, 0);
-		return false; 
-	}
 
 	memcpy(_signing_current_nonce, (uint8_t*)msg.getCustom(), MAX_PAYLOAD);
 	// We set the part of the 32-byte nonce that does not fit into a message to 0xAA
 	memset(&_signing_current_nonce[MAX_PAYLOAD], 0xAA, sizeof(_signing_current_nonce)-MAX_PAYLOAD);
-	return true;
 }
 
 bool signerAtsha204SoftSignMsg(MyMessage &msg) {