def serve_cb(watcher, revents): global connection_map, conn_sock data, addr = c_recvfrom(conn_sock, 4096) if addr not in connection_map: print("data0 is %d" % data[0]) if int(data[0]) != 0: # DH Key Exchange Packet print("Ignoring garbage data from %s" % addr[0]) return # Ignore this connection name_end = data.find(b'\0', 1) name = data[1:name_end] kexpkt = data[name_end+1:] if not peer_exists(name, pfile=WHITELIST_FILE): print("Ignoring unknown peer \"%s\" from %s" % (name, addr[0])) return # Ignore this connection peer_public_key = get_peer_public_key(name, pfile=WHITELIST_FILE) try: result = nacl.crypto_sign_open(kexpkt, peer_public_key) except Exception: print("Invalid signature from peer \"%s\" from %s" % \ (name, addr[0])) return # Ignore this connection print("Accepted connection from peer \"%s\" from %s" % (name, addr[0])) connection_map[addr] = ServeConnection(conn_sock, addr, name, peer_public_key, result) else: print("packet from %s" % addr[0]) connection_map[addr].raw_recv(data)
def key_get_exchange(self): nonce = '\0' * self.nonce_bytes authpkt = nacl.crypto_stream_xor(data, nonce, self.key) try: peer_dhpk = nacl.crypto_sign_open(authpkt, self.peer_public_key) except Exception: print("Invalid signature from peer \"%s\" from %s" % \ (name, addr[0])) sys.exit(0) if self.kex_init: self.key = nacl.crypto_scalarmult(self.dhsk, peer_dhpk) self.nonce_prefix = nacl.crypto_auth(config.get("netshrink", "nonce_prefix"), self.key)[:23-self.nonce_bytes] self.dhsk = None self.kex_init = False return dhpk, dhsk = nacl.crypto_box_keypair() authpkt = nacl.crypto_sign(dhpk, self.secret_key) crypted_data = nonce_out + nacl.crypto_stream_xor(authpkt, '\x01' + self.nonce_prefix + nonce, self.key) mac = nacl.crypto_auth(crypted_data, self.key)[:self.mac_bytes] c_sendto(self.sock, mac + crypted_data, self.addr) self.key = nacl.crypto_scalarmult(dhsk, peer_dhpk) print("New key is %s"%repr(self.key))
def __init__(self, sock, addr): self.sock = sock self.addr = addr self.name, self.public_key, self.secret_key = load_identity() dhpk, self.dhsk = nacl.crypto_box_keypair() self.mac_bytes = config.getint("netshrink","mac_bytes") if self.mac_bytes > 32: self.mac_bytes = 32 self.nonce_bytes = config.getint("netshrink","nonce_bytes") if self.nonce_bytes > 8: self.nonce_bytes = 8 self.nonce = 0 self.peer_nonce = 0 self.kex_init = False authpkt = b'\0' + self.name.encode("utf8") + b'\0' authpkt += nacl.crypto_sign(dhpk, self.secret_key) c_sendto(self.sock, authpkt, self.addr) while True: data, inaddr = c_recvfrom(self.sock, 4096) if int(data[0]) != 0: print("Ignoring garbage data from %s" % inaddr[0]) continue name_end = data.find(b'\0', 1) self.peer_name = data[1:name_end].encode("utf8") kexpkt = data[name_end+1:] if not peer_exists(self.name): print("Peer \"%s\" is unknown, but you are whitelisted." % \ self.peer_name) print("Please run addpeer/getpeer to authenticate.") sys.exit(0) self.peer_public_key = get_peer_public_key(self.peer_name) try: peer_dhpk = nacl.crypto_sign_open(kexpkt, self.peer_public_key) except Exception: print("Invalid signature from peer \"%s\" from %s" % \ (self.peer_name, inaddr[0])) sys.exit(0) break print("Accepted connection from peer \"%s\" from %s" % \ (self.peer_name, addr[0])) self.key = nacl.crypto_scalarmult(self.dhsk, peer_dhpk) self.dhsk = None if self.nonce_bytes: self.nonce_prefix = nacl.crypto_auth(config.get("netshrink", "nonce_prefix"), self.key)[:23-self.nonce_bytes] else: self.nonce_prefix = nacl.crypto_auth(config.get("netshrink", "nonce_prefix"), self.key)[:23] print("len of nonce_prefix is %d"%len(self.nonce_prefix)) for i in xrange(260): self.send("Hello there")
def verify(self, item): msg, auth = item[:4], item[4] if not self.pubkey: return True hashed, should = "1", "2" try: data = self.p.pack(msg) should = nacl.crypto_sign_open(auth, self.pubkey) hashed = nacl.crypto_hash_sha256(data) except: #pass import traceback traceback.print_exc() if hashed == should or DEBUG: return True return False
def test_signature(self): sm = nacl.crypto_sign(self.msg, self.sk) r = nacl.crypto_sign_open(sm, self.pk) self.assertEqual(r, self.msg)