ndpjsmmg

1--[[
2Securenet Modem API
3Code (C) DuskTheDutchie, 2020
4This API intends to bring semi-secure comm power
5over modems at the low-level Modem API included
6with CC.
7Features twin modem support, intended for 
8a wireless and wired modem.
9--]]
10
11--MessageFormat {header, data}
12--Header is a filtering thing
13
14netKey = nil
15
16modem1 = nil
17modem1Wireless = nil
18modem2 = nil
19modem2Wireless = nil
20
21openChannels = {}
22
23
24--Load a string utility API.
25--If it does not exist, download it from pastebin.
26if fs.exists("strutil") then
27 os.loadAPI("strutil")
28else
29 shell.run("pastebin get ppJ0ggSq strutil")
30 os.loadAPI("strutil")
31end
32
33--Check to see if we have a UUID-Key for secure
34--transmissions.
35if fs.exists("network.key") then
36 f = fs.open("network.key", "r")
37 netKey = f.readAll()
38 f.close()
39else
40 error("No network key detected. Install a network key before continuing.")
41end 
42
43--If we are at this point, then we have the
44--string utility and designated network key.
45
46
47--Call this when program starts.
48--Autodetect the modems based on start.
49function detectModems()
50 for k,v in pairs(rs.getSides()) do
51  if peripheral.getType(v) == "modem" and not modem1 then
52   modem1 = peripheral.wrap(v)
53   modem1Wireless = modem1.isWireless()
54  elseif peripheral.getType(v) == "modem" and not modem2 then
55   modem2 = peripheral.wrap(v)
56   modem2Wireless = modem2.isWireless()
57  end
58 end
59end
60
61--Open a channel for listening on both modems.
62function openChannel(channelNum)
63 if #openChannels < 128 then
64  table.insert(openChannels, channelNum)
65  if not modem1 then
66   error("No modems detected.")
67  else
68   modem1.open(channelNum)
69  end
70  if modem2 then
71   modem2.open(channelNum)
72  end
73 end
74end
75
76--Close a channel for listening on both modems.
77function closeChannel(spec)
78 for i=1, #openChannels do
79  if openChannels[i] == spec then
80   if modem1 then
81    modem1.close(spec)
82   else
83    error("No modems detected.")
84   end
85   if modem2 then
86    modem2.close(spec)
87   end
88  end
89 end
90end
91
92--Close all open channels on both modems.
93function closeAllOpen()
94 for i=1, #openChannels do
95  if modem1 then
96   modem1.close(openChannels[i])
97  else
98   error("No modems detected.")
99  end
100  if modem2 then
101   modem2.close(openChannels[i])
102  end
103 end
104 openChannels = {}
105end
106
107--Send a message on the specified channel.
108
109function sendMessage(chaNum, respNum, msg, secure, wireless)
110 if not respNum or not chaNum then
111  error("Missing parameters: Channel Number or Response Number")
112 end
113 
114 if secure == true then
115  msg = strutil.encrypt(msg, netKey)
116 end
117 
118 --Transmit on the wireless modem.
119 if wireless == true then
120  if modem1Wireless == true then
121   modem1.transmit(chaNum, respNum, msg)
122  elseif modem2Wireless == true then
123   modem2.transmit(chaNum, respNum, msg)
124  end
125 else
126 --Transmit on the wired modem.
127  if modem1Wireless == false then
128   modem1.transmit(chaNum, respNum, msg)
129  elseif modem2Wireless == false then
130   modem2.transmit(chaNum, respNum, msg)
131  end
132 end
133end 
134
135function receiveMessage(secure, timeout)
136 if timeout then
137  os.startTimer(timeout)
138 end
139 while true do
140  event, mSide, msgChannel, respChannel, msg = os.pullEvent()
141  if event == "modem_message" then
142   if secure then
143    msg = strutil.decrypt(msg, netKey)
144    return msg, msgChannel, respChannel, mSide
145   else
146    return msg, msgChannel, respChannel, mSide
147   end
148  elseif event == "timer" then
149   print("Timed out.")
150   return nil, nil, nil, nil
151  end
152  sleep(0.1)
153 end
154end
155