encrypt

local function enc(str, key)
        if not key then return false end
        local f = ""
        local kb = {}
        for i = 1, #key do
                kb[i] = string.byte(key:sub(i,i)) - 31
        end
        local c = 1
        for i = 1, #str do
                local t1 = string.byte(str:sub(i,i))
                if t1 == 10 then
                        f = f .. string.char(10)
                else
                        local t2 = t1 + kb[c]
                        if t2 > 126 then
                                local t3 = t2 - 126
                                t2 = 31 + t3
                        end
                f = f .. string.char(t2)
                end
                c = c + 1
                if c > #key then
                        c = 1
                end
        end
        return f
end
 
local function dec(str, key)
        if not key then return false end
        local f = ""
        local kb = {}
        for i = 1, #key do
                kb[i] = string.byte(key:sub(i,i)) - 31
        end
        local c = 1
        for i = 1, #str do
                local t2 = string.byte(str:sub(i,i)) - 31
                if t2 == -21 then
                        f = f .. string.char(10)
                else
                        local t3 = t2 - kb[c] + 31
                        if t3 < 32 then
                                t3 = t3 + 126 - 31
                        end
                        if t3 < 32 then return false, t3 end
                        if t3 > 126 then return false, t3 end
                        f = f .. string.char(t3)
                end
                c = c + 1
                if c > #key then
                        c = 1
                end
        end
        return f
end
 
function encrypt(str, key)
        if not key then return false end
        if #key < 3 then return false end
        local f = str
        key = key .. key .. "#me1"
        for i = 0, #key - 1 do
                f = enc(f, key:sub(i,i + 1))
        end
        f = enc(f, key:sub(1,2) .. key:sub(#key - 1, #key) .. enc(key, key .. key))
        return f
end
 
function decrypt(str, key)
        if not key then return false end
        if #key < 3 then return false end
        local f = str
        key = key .. key .. "#me1"
        for i = 0, #key - 1 do
                f = dec(f, key:sub(i,i + 1))
        end
        f = dec(f, key:sub(1,2) .. key:sub(#key - 1, #key) .. enc(key, key .. key))
        return f
end