typo

ccpi.lua

@@ -62,7 +62,7 @@ local function draw(img, ox, oy, monitor)
         t.setPaletteColor(colors_list[i], img.palette[i])
     end
 
-    t.setTextScale(image.scale)
+    t.setTextScale(img.scale)
 
     for y = 1, img.h do
         t.setCursorPos(ox, oy + y - 1)

dh/dh.lua

@@ -0,0 +1,71 @@
+local ecc = require("ecc")
+
+string.toHex = function(str)
+    return str:gsub(".", function(ch) return string.format("%02x", ch:byte()) end)
+end
+string.fromHex = function(hex)
+    return hex:gsub("%x%x", function(d) return string.char(tonumber(d, 16)) end)
+end
+
+local keypair = {}
+if fs.exists("/.id_dh.json") then
+    local fp = io.open("/.id_dh.json", "r")
+    local d = textutils.unserializeJSON(fp:read())
+    keypair.sk = string.fromHex(d.secret)
+    keypair.pk = string.fromHex(d.public)
+    fp:close()
+else
+    printError("no identity found, generating...")
+    local sk, pk = ecc.keypair(ecc.random.random())
+    io.open("/.id_dh.json", "w"):write(textutils.serializeJSON({
+        secret = string.toHex(sk),
+        public = string.toHex(pk)
+    })):close()
+    keypair.sk = string.char(table.unpack(sk))
+    keypair.pk = string.char(table.unpack(pk))
+end
+
+print("pubkey: "..string.toHex(keypair.pk))
+
+local running = true
+
+local known_hosts = {}
+
+parallel.waitForAll(function() while running do -- dh:discover sender
+    rednet.broadcast(keypair.pk, "dh:discover")
+    os.sleep(10)
+end end,
+function() while running do -- dh:discover handler
+    local id, pk, proto = rednet.receive("dh:discover")
+    if proto == "dh:discover" then
+        print("DH discover from "..id.." with key "..pk)
+        local nonce = string.toHex(ecc.random.random())
+        local key = ecc.exchange(keypair.sk, pk)
+        known_hosts[id] = {
+            id = id,
+            pk = pk,
+            sk = key,
+            verified = false,
+            nonce = nonce,
+            t = os.clock()
+        }
+        known_hosts[pk] = known_hosts[id]
+        rednet.send(id, {
+            pk = keypair.pk,
+            msg = ecc.encrypt(nonce, key)
+        }, "dh:pair")
+    end
+end end,
+function() while running do -- dh:pair handler
+    local id, msg, proto = rednet.receive("dh:pair")
+    if proto == "dh:pair" then
+        local key = ecc.exchange(keypair.sk, msg.pk)
+        known_hosts[id] = {
+            id = id,
+            pk = msg.pk,
+            sk = key,
+            verified = false,
+            nonce = ecc.decrypt(msg.msg, msg.msg)
+        }
+    end
+end end)