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#51 hmac verification

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This commit is contained in:
Mikayla
2023-06-11 18:26:55 +00:00
parent 302f3d913f
commit ef5567ad46
15 changed files with 286 additions and 2361 deletions
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43
scada-common/comms.lua
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@@ -7,14 +7,14 @@ local log = require("scada-common.log")
local insert = table.insert
---@diagnostic disable-next-line: undefined-field
local C_ID = os.getComputerID() ---@type integer computer ID
local COMPUTER_ID = os.getComputerID() ---@type integer computer ID
local max_distance = nil ---@type number|nil maximum acceptable transmission distance
local max_distance = nil ---@type number|nil maximum acceptable transmission distance
---@class comms
local comms = {}
comms.version = "2.0.0"
comms.version = "2.1.0"
---@enum PROTOCOL
local PROTOCOL = {
@@ -149,6 +149,7 @@ function comms.scada_packet()
dest_addr = comms.BROADCAST,
seq_num = -1,
protocol = PROTOCOL.SCADA_MGMT,
mac = "",
length = 0,
payload = {}
}
@@ -163,14 +164,13 @@ function comms.scada_packet()
---@param payload table
function public.make(dest_addr, seq_num, protocol, payload)
self.valid = true
---@diagnostic disable-next-line: undefined-field
self.src_addr = C_ID
self.src_addr = COMPUTER_ID
self.dest_addr = dest_addr
self.seq_num = seq_num
self.protocol = protocol
self.length = #payload
self.payload = payload
self.raw = { self.src_addr, self.dest_addr, self.seq_num, self.protocol, self.payload }
self.raw = { self.src_addr, self.dest_addr, self.seq_num, self.protocol, self.mac, self.payload }
end
-- parse in a modem message as a SCADA packet
@@ -198,43 +198,58 @@ function comms.scada_packet()
-- log.debug("comms.scada_packet.receive(): discarding packet with distance " .. distance .. " outside of trusted range")
else
if type(self.raw) == "table" then
if #self.raw == 5 then
if #self.raw == 6 then
self.src_addr = self.raw[1]
self.dest_addr = self.raw[2]
self.seq_num = self.raw[3]
self.protocol = self.raw[4]
self.mac = self.raw[5]
-- element 5 must be a table
if type(self.raw[5]) == "table" then
self.length = #self.raw[5]
self.payload = self.raw[5]
if type(self.raw[6]) == "table" then
self.length = #self.raw[6]
self.payload = self.raw[6]
end
else
self.src_addr = nil
self.dest_addr = nil
self.seq_num = nil
self.protocol = nil
self.mac = ""
self.length = 0
self.payload = {}
end
-- check if this packet is destined for this device
local is_destination = (self.dest_addr == comms.BROADCAST) or (self.dest_addr == C_ID)
local is_destination = (self.dest_addr == comms.BROADCAST) or (self.dest_addr == COMPUTER_ID)
self.valid = is_destination and type(self.src_addr) == "number" and type(self.dest_addr) == "number" and
type(self.seq_num) == "number" and type(self.protocol) == "number" and type(self.payload) == "table"
self.valid = is_destination and
type(self.src_addr) == "number" and
type(self.dest_addr) == "number" and
type(self.seq_num) == "number" and
type(self.protocol) == "number" and
type(self.mac) == "string" and
type(self.payload) == "table"
end
end
return self.valid
end
-- set message authentication code
function public.set_mac(code)
self.mac = code
self.raw = { self.src_addr, self.dest_addr, self.seq_num, self.protocol, self.mac, self.payload }
end
-- public accessors --
---@nodiscard
function public.modem_event() return self.modem_msg_in end
---@nodiscard
function public.raw_sendable() return self.raw end
---@nodiscard
function public.raw_verifiable() return { self.src_addr, self.dest_addr, self.seq_num, self.protocol, "", self.payload } end
---@nodiscard
function public.local_channel() return self.modem_msg_in.s_channel end
@@ -253,6 +268,8 @@ function comms.scada_packet()
---@nodiscard
function public.protocol() return self.protocol end
---@nodiscard
function public.mac() return self.mac end
---@nodiscard
function public.length() return self.length end
---@nodiscard
function public.data() return self.payload end