Add uint16_t key to Hashtable, and make Salsa20 zero its keyspace on destruction.

node/Salsa20.hpp

@@ -12,6 +12,7 @@
 #include <stdlib.h>
 
 #include "Constants.hpp"
+#include "Utils.hpp"
 
 #if (!defined(ZT_SALSA20_SSE)) && (defined(__SSE2__) || defined(__WINDOWS__))
 #define ZT_SALSA20_SSE 1
@@ -31,6 +32,8 @@ class Salsa20
 public:
 	Salsa20() throw() {}
 
+	~Salsa20() { Utils::burn(&_state,sizeof(_state)); }
+
 	/**
 	 * @param key Key bits
 	 * @param kbits Number of key bits: 128 or 256 (recommended)