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add wireshark support for UDP
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konsumer committed Jan 7, 2017
1 parent 6824e1a commit 8ee80fe
Showing 1 changed file with 36 additions and 56 deletions.
92 changes: 36 additions & 56 deletions tplink-smarthome.lua
Original file line number Diff line number Diff line change
Expand Up @@ -24,65 +24,45 @@
--

-- Create TP-Link Smart Home protocol and its fields
p_tplink = Proto ("TPLink-SmartHome","TP-Link Smart Home Protocol")
hs1x0_proto_TCP = Proto ("TPLink-SmartHome-TCP", "TP-Link Smart Home Protocol (TCP")
hs1x0_proto_UDP = Proto ("TPLink-SmartHome-UDP", "TP-Link Smart Home Protocol (UDP)")

-- Dissector function
function p_tplink.dissector (buf, pkt, root)
-- Validate packet length
if buf:len() == 0 then return end
pkt.cols.protocol = p_tplink.name

-- Decode data
local ascii = ""
local hex = ""

-- Skip first 4 bytes (header)
start = 4
endPosition = buf:len() - 1

-- Decryption key is -85 (256-85=171)
local key = 171

-- Decrypt Autokey XOR
-- Save results as ascii and hex
for index = start, endPosition do
local c = buf(index,1):uint()
-- XOR first byte with key
d = bit32.bxor(c,key)
-- Use byte as next key
key = c

hex = hex .. string.format("%x", d)
-- Convert to printable characters
if d >= 0x20 and d <= 0x7E then
ascii = ascii .. string.format("%c", d)
else
-- Use dot for non-printable bytes
ascii = ascii .. "."
end
end
-- Decrypt string Autokey XOR to ByteArray
function tpdecode(buf, start)
local key = 171
local size = buf:len()-1
local decoded = ""
for i=start,size do
local c = buf(i,1):uint()
decoded = decoded .. string.format("%x", bit.bxor(c,key))
key = c
end
return ByteArray.new(decoded)
end


-- Create subtree
subtree = root:add(p_tplink, buf(0))

-- Add data to subtree
subtree:add(ascii)
-- Description of payload
function hs1x0_proto_TCP.dissector (buf, pkt, root)
pkt.cols.protocol = "TPLink-SmartHome (TCP)"
local subtree = root:add(hs1x0_proto_TCP, buf() ,"TPLink-SmartHome")
local decoded = tpdecode(buf, 4)
subtree:add(decoded:raw())
subtree:append_text(" (decrypted)")

-- Call JSON Dissector with decrypted data
local b = ByteArray.new(hex)
local tvb = ByteArray.tvb(b, "JSON TVB")
local tvb = ByteArray.tvb(decoded, "JSON TVB")
Dissector.get("json"):call(tvb, pkt, root)

end

-- Initialization routine
function p_tplink.init()

function hs1x0_proto_UDP.dissector (buf, pkt, root)
pkt.cols.protocol = "TPLink-SmartHome (UDP)"
local subtree = root:add(hs1x0_proto_UDP, buf() ,"TPLink-SmartHome")
local decoded = tpdecode(buf, 0)
subtree:add(decoded:raw())
subtree:append_text(" (decrypted)")
local tvb = ByteArray.tvb(decoded, "JSON TVB")
Dissector.get("json"):call(tvb, pkt, root)
end

-- Register a chained dissector for port 9999
local tcp_dissector_table = DissectorTable.get("tcp.port")
dissector = tcp_dissector_table:get_dissector(9999)
tcp_dissector_table:add(9999, p_tplink)

tcp_table = DissectorTable.get ("tcp.port")
udp_table = DissectorTable.get ("udp.port")

-- register the protocol to port 9999
tcp_table:add (9999, hs1x0_proto_TCP)
udp_table:add (9999, hs1x0_proto_UDP)

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