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mirror of https://github.com/osmarks/random-stuff synced 2024-11-08 13:39:53 +00:00
random-stuff/computercraft/remote_drone.lua
2023-11-13 19:37:05 +00:00

182 lines
6.2 KiB
Lua

local string, assert = string, assert
-- Initialize table of round constants
-- (first 32 bits of the fractional parts of the cube roots of the first
-- 64 primes 2..311):
local k = {
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
}
local function rrotate (x, n)
return ((x >> n) | (x << (32 - n))) -- (1)
end
-- transform a string of bytes in a string of hexadecimal digits
local function str2hexa (s)
local h = string.gsub(s, ".", function(c)
return string.format("%02x", string.byte(c))
end)
return h
end
local function num2s(n, l)
return ("\0"):rep(l - 4) .. string.char((n >> 24) & 0xFF) .. string.char((n >> 16) & 0xFF) .. string.char((n >> 8) & 0xFF) .. string.char(n & 0xFF)
end
local function preproc (msg, len)
local extra = 64 - ((len + 1 + 8) % 64)
len = num2s(8 * len, 8) -- original len in bits, coded
msg = msg .. "\128" .. string.rep("\0", extra) .. len
assert(#msg % 64 == 0)
return msg
end
local function undumpint(str, spos)
return (str:byte(spos) << 24) + (str:byte(spos + 1) << 16) + (str:byte(spos + 2) << 8) + str:byte(spos + 3)
end
local function digestblock (msg, i, H)
-- break chunk into sixteen 32-bit big-endian words w[1..16]
local w = {}
for j = 1, 16 do
w[j] = undumpint(msg, i) & 0xffffffff
i = i + 4 -- index for next block
end
-- Extend the sixteen 32-bit words into sixty-four 32-bit words:
for j = 17, 64 do
local v = w[j - 15]
local s0 = rrotate(v, 7) ~ rrotate(v, 18) ~ (v >> 3) -- (1)
v = w[j - 2]
local s1 = rrotate(v, 17) ~ rrotate(v, 19) ~ (v >> 10) -- (1)
w[j] = (w[j - 16] + s0 + w[j - 7] + s1) & 0xffffffff -- (2)
end
-- Initialize hash value for this chunk:
local a, b, c, d, e, f, g, h = H[1], H[2], H[3], H[4], H[5], H[6], H[7], H[8]
-- Main loop:
for i = 1, 64 do
local s0 = rrotate(a, 2) ~ rrotate(a, 13) ~ rrotate(a, 22) -- (1)
local maj = (a & b) ~ (a & c) ~ (b & c)
local t2 = s0 + maj -- (1)
local s1 = rrotate(e, 6) ~ rrotate(e, 11) ~ rrotate(e, 25) -- (1)
local ch = (e & f) ~ (~e & g)
local t1 = h + s1 + ch + k[i] + w[i] -- (1)
h = g
g = f
f = e
e = (d + t1) & 0xffffffff -- (2)
d = c
c = b
b = a
a = (t1 + t2) & 0xffffffff -- (2)
end
-- Add (mod 2^32) this chunk's hash to result so far:
H[1] = (H[1] + a) & 0xffffffff
H[2] = (H[2] + b) & 0xffffffff
H[3] = (H[3] + c) & 0xffffffff
H[4] = (H[4] + d) & 0xffffffff
H[5] = (H[5] + e) & 0xffffffff
H[6] = (H[6] + f) & 0xffffffff
H[7] = (H[7] + g) & 0xffffffff
H[8] = (H[8] + h) & 0xffffffff
end
local function hash256 (msg)
msg = preproc(msg, #msg)
local H = {0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 }
for i = 1, #msg, 64 do
digestblock(msg, i, H)
end
return str2hexa(num2s(H[1], 4)..num2s(H[2], 4)..num2s(H[3], 4)..num2s(H[4], 4)..num2s(H[5], 4)..num2s(H[6], 4)..num2s(H[7], 4)..num2s(H[8], 4))
end
local function compact_serialize(x)
local t = type(x)
if t == "number" then
return tostring(x)
elseif t == "string" then
return ("%q"):format(x)
elseif t == "table" then
local out = "{ "
for k, v in pairs(x) do
out = out .. string.format("[%s]=%s, ", compact_serialize(k), compact_serialize(v))
end
return out .. "}"
else return tostring(x) end
end
if require then
component = require "component"
computer = require "computer"
end
computer.beep(400)
--local net = component.proxy(component.list "internet"())
local modem_id = component.list "modem"()
local eeprom = component.proxy(component.list "eeprom"())
local psk = eeprom.getData()
if #psk < 16 then
while true do computer.beep(2000) end
end
local modem = component.proxy(modem_id)
modem.open(46110) -- command channel
local used_nonces = {}
local function is_new(received_nonce)
for _, nonce in pairs(used_nonces) do
if nonce == received_nonce then return false end
end
return true
end
while true do
local event, to, from, port, distance, message, signature, target, nonce = computer.pullSignal()
print("M", message, "S", signature, "T", target, "N", nonce)
if event == "modem_message" and port == 46110 and type(message) == "string" and type(signature) == "string" and type(target) == "string" and type(nonce) == "string" and is_new(nonce) then
local sig_val = message .. psk .. target .. nonce
print(target, sig_val, "HASH=", hash256(sig_val), signature)
if hash256(sig_val) == signature then
if target == "" or modem_id:match(target) then
table.insert(used_nonces, nonce)
if #used_nonces > 128 then
table.remove(used_nonces, 1)
end
local f, e = load(message, "@<remote>")
if f then
f, e = pcall(f)
end
local response = compact_serialize { f, e }
modem.broadcast(46111, response, hash256(response .. psk .. tostring(modem_id) .. nonce), modem_id, nonce)
end
else
computer.beep(200)
end
end
end