Add a bit of hardening in the network certificate of membership by incorporating a full hash of the identity to which it is issued. This means the recipient need not depend entirely on the root verifying identities properly to make sure impersonation is not occurring.

node/Identity.hpp

@@ -109,6 +109,18 @@ public:
 	 */
 	inline bool hasPrivate() const { return (_privateKey != (C25519::Private *)0); }
 
+	/**
+	 * Compute a SHA384 hash of this identity's address and public key(s).
+	 * 
+	 * @param sha384buf Buffer with 48 bytes of space to receive hash
+	 */
+	inline void publicKeyHash(void *sha384buf) const
+	{
+		uint8_t address[ZT_ADDRESS_LENGTH];
+		_address.copyTo(address, ZT_ADDRESS_LENGTH);
+		SHA384(sha384buf, address, ZT_ADDRESS_LENGTH, _publicKey.data, ZT_C25519_PUBLIC_KEY_LEN);
+	}
+
 	/**
 	 * Compute the SHA512 hash of our private key (if we have one)
 	 *