Remove global initialization of sha256

libraries/MySensors/MySigningDriverAtsha204Soft.cpp

@@ -40,10 +40,14 @@ static void DEBUG_ATSHASOFT_PRINTBUF(char* str, uint8_t* buf, uint8_t sz)
 #define DEBUG_ATSHASOFT_PRINTBUF(str, buf, sz)
 #endif
 
-static Sha256Class Sha256;
+MySigningDriverAtsha204Soft::MySigningDriverAtsha204Soft()
+	:
+	MySigningDriver(),
+	hmacKey({MY_HMAC_KEY}),
+	verification_ongoing(false),
+	Sha256()
 
-MySigningDriverAtsha204Soft::MySigningDriverAtsha204Soft() : MySigningDriver(), hmacKey({MY_HMAC_KEY}) {
-	verification_ongoing = false;
+{
 	// We set the part of the 32-byte nonce that does not fit into a message to 0xAA
 	memset(current_nonce, 0xAA, sizeof(current_nonce));
 }

libraries/MySensors/MySigningDriverAtsha204Soft.h

@@ -13,6 +13,7 @@
 #include "MyConfig.h"
 #include "MySigningDriver.h"
 #include "utility/ATSHA204.h"
+#include "utility/sha256.h"
 #include <stdint.h>
 
 #define SIGNING_IDENTIFIER (1)
@@ -34,6 +35,7 @@ public:
 	bool signMsg(MyMessage &msg);
 	bool verifyMsg(MyMessage &msg);
 private:
+	Sha256Class Sha256;
 	unsigned long timestamp;
 	bool verification_ongoing;
 	uint8_t current_nonce[NONCE_NUMIN_SIZE_PASSTHROUGH];

libraries/MySensors/utility/sha256.cpp

@@ -3,6 +3,7 @@
 #include <avr/pgmspace.h>
 #include "sha256.h"
 
+
 const uint32_t sha256K[] PROGMEM = {
   0x428a2f98,0x71374491,0xb5c0fbcf,0xe9b5dba5,0x3956c25b,0x59f111f1,0x923f82a4,0xab1c5ed5,
   0xd807aa98,0x12835b01,0x243185be,0x550c7dc3,0x72be5d74,0x80deb1fe,0x9bdc06a7,0xc19bf174,