mirror of
https://github.com/MikaylaFischler/cc-mek-scada.git
synced 2024-08-30 18:22:34 +00:00
247 lines
7.1 KiB
Lua
247 lines
7.1 KiB
Lua
local aes128 = require("lockbox.cipher.aes128")
|
|
local ctr_mode = require("lockbox.cipher.mode.ctr");
|
|
|
|
local sha1 = require("lockbox.digest.sha1");
|
|
local sha2_224 = require("lockbox.digest.sha2_224");
|
|
local sha2_256 = require("lockbox.digest.sha2_256");
|
|
|
|
local pbkdf2 = require("lockbox.kdf.pbkdf2")
|
|
|
|
local hmac = require("lockbox.mac.hmac")
|
|
|
|
local zero_pad = require("lockbox.padding.zero");
|
|
|
|
local stream = require("lockbox.util.stream")
|
|
local array = require("lockbox.util.array")
|
|
|
|
local log = require("scada-common.log")
|
|
local util = require("scada-common.util")
|
|
|
|
local crypto = {}
|
|
|
|
local c_eng = {
|
|
key = nil,
|
|
cipher = nil,
|
|
decipher = nil,
|
|
hmac = nil
|
|
}
|
|
|
|
---@alias hex string
|
|
|
|
-- initialize cryptographic system
|
|
function crypto.init(password, server_port)
|
|
local key_deriv = pbkdf2()
|
|
|
|
-- setup PBKDF2
|
|
-- the primary goal is to just turn our password into a 16 byte key
|
|
key_deriv.setPassword(password)
|
|
key_deriv.setSalt("salty_salt_at_" .. server_port)
|
|
key_deriv.setIterations(32)
|
|
key_deriv.setBlockLen(8)
|
|
key_deriv.setDKeyLen(16)
|
|
|
|
local start = util.time()
|
|
|
|
key_deriv.setPRF(hmac().setBlockSize(64).setDigest(sha2_256))
|
|
key_deriv.finish()
|
|
|
|
log.dmesg("pbkdf2: key derivation took " .. (util.time() - start) .. "ms", "CRYPTO", colors.yellow)
|
|
|
|
c_eng.key = array.fromHex(key_deriv.asHex())
|
|
|
|
-- initialize cipher
|
|
c_eng.cipher = ctr_mode.Cipher()
|
|
c_eng.cipher.setKey(c_eng.key)
|
|
c_eng.cipher.setBlockCipher(aes128)
|
|
c_eng.cipher.setPadding(zero_pad);
|
|
|
|
-- initialize decipher
|
|
c_eng.decipher = ctr_mode.Decipher()
|
|
c_eng.decipher.setKey(c_eng.key)
|
|
c_eng.decipher.setBlockCipher(aes128)
|
|
c_eng.decipher.setPadding(zero_pad);
|
|
|
|
-- initialize HMAC
|
|
c_eng.hmac = hmac()
|
|
c_eng.hmac.setBlockSize(64)
|
|
c_eng.hmac.setDigest(sha1)
|
|
c_eng.hmac.setKey(c_eng.key)
|
|
|
|
log.dmesg("init: completed in " .. (util.time() - start) .. "ms", "CRYPTO", colors.yellow)
|
|
end
|
|
|
|
-- encrypt plaintext
|
|
---@param plaintext string
|
|
---@return string initial_value, string ciphertext
|
|
function crypto.encrypt(plaintext)
|
|
local start = util.time()
|
|
|
|
-- initial value
|
|
local iv = {
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255),
|
|
math.random(0, 255)
|
|
}
|
|
|
|
log.debug("crypto.random: iv random took " .. (util.time() - start) .. "ms")
|
|
|
|
start = util.time()
|
|
|
|
c_eng.cipher.init()
|
|
c_eng.cipher.update(stream.fromArray(iv))
|
|
c_eng.cipher.update(stream.fromString(plaintext))
|
|
c_eng.cipher.finish()
|
|
|
|
local ciphertext = c_eng.cipher.asHex() ---@type hex
|
|
|
|
log.debug("crypto.encrypt: aes128-ctr-mode took " .. (util.time() - start) .. "ms")
|
|
log.debug("ciphertext: " .. ciphertext)
|
|
|
|
return iv, ciphertext
|
|
end
|
|
|
|
-- decrypt ciphertext
|
|
---@param iv string CTR initial value
|
|
---@param ciphertext string ciphertext hex
|
|
---@return string plaintext
|
|
function crypto.decrypt(iv, ciphertext)
|
|
local start = util.time()
|
|
|
|
c_eng.decipher.init()
|
|
c_eng.decipher.update(stream.fromArray(iv))
|
|
c_eng.decipher.update(stream.fromHex(ciphertext))
|
|
c_eng.decipher.finish()
|
|
|
|
local plaintext_hex = c_eng.decipher.asHex() ---@type hex
|
|
|
|
local plaintext = stream.toString(stream.fromHex(plaintext_hex))
|
|
|
|
log.debug("crypto.decrypt: aes128-ctr-mode took " .. (util.time() - start) .. "ms")
|
|
log.debug("plaintext: " .. plaintext)
|
|
|
|
return plaintext
|
|
end
|
|
|
|
-- generate HMAC of message
|
|
---@param message_hex string initial value concatenated with ciphertext
|
|
function crypto.hmac(message_hex)
|
|
local start = util.time()
|
|
|
|
c_eng.hmac.init()
|
|
c_eng.hmac.update(stream.fromHex(message_hex))
|
|
c_eng.hmac.finish()
|
|
|
|
local hash = c_eng.hmac.asHex() ---@type hex
|
|
|
|
log.debug("crypto.hmac: hmac-sha1 took " .. (util.time() - start) .. "ms")
|
|
log.debug("hmac: " .. hash)
|
|
|
|
return hash
|
|
end
|
|
|
|
-- wrap a modem as a secure modem to send encrypted traffic
|
|
---@param modem table modem to wrap
|
|
function crypto.secure_modem(modem)
|
|
local self = {
|
|
modem = modem
|
|
}
|
|
|
|
---@class secure_modem
|
|
---@field open function
|
|
---@field isOpen function
|
|
---@field close function
|
|
---@field closeAll function
|
|
---@field isWireless function
|
|
---@field getNamesRemote function
|
|
---@field isPresentRemote function
|
|
---@field getTypeRemote function
|
|
---@field hasTypeRemote function
|
|
---@field getMethodsRemote function
|
|
---@field callRemote function
|
|
---@field getNameLocal function
|
|
local public = {}
|
|
|
|
-- wrap a modem
|
|
---@param modem table
|
|
---@diagnostic disable-next-line: redefined-local
|
|
function public.wrap(modem)
|
|
self.modem = modem
|
|
for key, func in pairs(self.modem) do
|
|
public[key] = func
|
|
end
|
|
end
|
|
|
|
-- wrap modem functions, then we replace transmit
|
|
public.wrap(self.modem)
|
|
|
|
-- send a packet with encryption
|
|
---@param channel integer
|
|
---@param reply_channel integer
|
|
---@param payload table packet raw_sendable
|
|
function public.transmit(channel, reply_channel, payload)
|
|
local plaintext = textutils.serialize(payload, { allow_repetitions = true, compact = true })
|
|
|
|
local iv, ciphertext = crypto.encrypt(plaintext)
|
|
---@diagnostic disable-next-line: redefined-local
|
|
local hmac = crypto.hmac(iv .. ciphertext)
|
|
|
|
self.modem.transmit(channel, reply_channel, { hmac, iv, ciphertext })
|
|
end
|
|
|
|
-- parse in a modem message as a network packet
|
|
---@param side string
|
|
---@param sender integer
|
|
---@param reply_to integer
|
|
---@param message any encrypted packet sent with secure_modem.transmit
|
|
---@param distance integer
|
|
---@return string side, integer sender, integer reply_to, any plaintext_message, integer distance
|
|
function public.receive(side, sender, reply_to, message, distance)
|
|
local body = ""
|
|
|
|
if type(message) == "table" then
|
|
if #message == 3 then
|
|
---@diagnostic disable-next-line: redefined-local
|
|
local hmac = message[1]
|
|
local iv = message[2]
|
|
local ciphertext = message[3]
|
|
|
|
local computed_hmac = crypto.hmac(iv .. ciphertext)
|
|
|
|
if hmac == computed_hmac then
|
|
-- message intact
|
|
local plaintext = crypto.decrypt(iv, ciphertext)
|
|
body = textutils.deserialize(plaintext)
|
|
|
|
if body == nil then
|
|
-- failed decryption
|
|
log.debug("crypto.secure_modem: decryption failed")
|
|
body = ""
|
|
end
|
|
else
|
|
-- something went wrong
|
|
log.debug("crypto.secure_modem: hmac mismatch violation")
|
|
end
|
|
end
|
|
end
|
|
|
|
return side, sender, reply_to, body, distance
|
|
end
|
|
|
|
return public
|
|
end
|
|
|
|
return crypto
|