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--colored chat messages by rnd
if not init then
friends = {boxface=1,FGH=1}
self.msg_filter("",true) -- record & hide all incoming messages
cfilter = {
["***"] = "pink",
["Message sent."] = false,
}
defaultcolor = "green";
password = { -- ~30 bits per row, 10x ~ 300 bit, 2 consecutive passwords should be different!
1410523800,
1000000001,
1000000002,
1000000003,
1002890004,
1000000005,
1000000006,
1000000007,
1000354008,
1000000009,
}
-- each password can be up to 10^10, plus random session key 4*10^13 for total 64*10^43 ~ 148.8 bits
chatversion = "04302018a";
-----------------------------------------------------------
init = true
say(minetest.colorize("red","#COLORED CHAT ".. chatversion .. " STARTED. "))
rndm = 2^31 − 1; --C++11's minstd_rand
rnda = 48271;
random = function(n)
rndseed = (rnda*rndseed)% rndm;
return rndseed % n
end
encrypt_ = function(input,password,sgn)
local n = 128-32+1; -- Z_97, 97 prime
local m = 32;
local ret = {};input = input or "";
rndseed = password;
local key = {};
local out = {};
for i=1, string.len(input) do
key[i] = random(n) -- generate keys from password
out[i] = string.byte(input,i)-m
if out[i] == -6 then out[i] = 96 end -- conversion back
end
if sgn > 0 then -- encrypt
for i=1, string.len(input) do
local offset=key[i]
local c = out[i];
local c0 = 0;
for j = 1,i-1 do c0 = c0 + (out[j])^3; c0 = c0 % n end
for j = i+1,string.len(input) do c0 = c0 + (out[j])^3; c0 = c0 % n end
c = (c+(c0+offset)*sgn) % n;
out[i] = c
end
else -- decrypt
local c0 = 0
for i = string.len(input),1,-1 do
local offset=key[i];
local c = out[i];
local c0 = 0;
for j = 1,i-1 do c0 = c0 + (out[j])^3; c0 = c0 % n end
for j = i+1,string.len(input) do c0 = c0 + (out[j])^3; c0 = c0 % n end
c = (c+(c0+offset)*sgn) % n;
out[i] = c
end
end
for i = 1, string.len(input) do
if out[i] == 96 then out[i]=-6 end -- 32 + 96 = 128 (bad char)
ret[#ret+1] = string.char(m+out[i])
end
return table.concat(ret,"")
end
encrypt = function(text,password)
local input = text;
local out = "";
for i = 1, #password do
input = encrypt_(input,password[i], (i%1)*2-1)
end
return input
end
decrypt = function(text, password)
local input = text;
local out = "";
for i = #password,1,-1 do
input = encrypt_(input,password[i], -(i%1)*2+1)
end
return input
end
end
local msg = ""
while msg do
msg = self.listen_msg()
if msg and msg~= "" then
color = defaultcolor;
for k,v in pairs(cfilter) do
local l = string.len(k);
if string.sub(msg,1,l) == k then
color = v;
end
end
if color then
if string.sub(msg,1,1) == "<" then -- chat
local i = string.find(msg,">");
local name = string.sub(msg,2,i-1)
if friends[name] then color = "orange" else color = "gray" end
msg = string.sub(msg,i+1)
say(" " .. minetest.colorize(color,name .. " > " .. msg ))
elseif string.sub(msg,1,2) == "PM" then -- private message
local i = string.find(msg,"from")+5;
local j = string.find(msg,":")+2;
local name = string.sub(msg,i,j-3);
if friends[name] then
msg = string.sub(msg,j)
say( minetest.colorize("orange", name .. " > " .. decrypt(msg,password)))
else
say( minetest.colorize("yellow",msg))
end
elseif string.sub(msg,1,11) == "The player " then
local i = string.find(msg," ", 12)
local name = string.sub(msg,12,i-1);
say("#CHAT: friend " .. name .. " is not online.")
friends[name]=nil
--say("XXX" .. string.sub(msg,12,i-1).."XXX")
else
say(minetest.colorize(color,msg))
end
end
end
end
msg = self.sent_msg()
if msg then
say(minetest.colorize("orange", "FRIENDS CHAT: " .. msg))
for name,_ in pairs(friends) do
say("/msg " .. name .. " " .. encrypt(msg,password),true)
end
end
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