jLogin login

--[[
    Project info:

    Name: jLogin
    Creator: Jesusthekiller
    Language: Lua (CC)
    Website: None
    License: GNU GPL
        License file can be fount at www.jesusthekiller.com/license-gpl.html

    Version: 1.0
]]--

--[[
    Changelog:
      1.0:
        Initial Release
]]--

--[[
    LICENSE:

    jLogin
    Copyright (c) 2013 Jesusthekiller

    This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

    See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.
]]--

if not sha256 then
    os.loadAPI("sha256")
end

local args = {...}

local function usage()
    print("Usage:")
    print("  login lock")
    print("  login adduser <login> <password>")
    print("  login deluser <login> <password>")
    print("  login passwd <login> <oldpass> <newpass>")
    return
end

if not fs.exists("login_users") then
    local f = fs.open("login_users", "w")
    f.close()
end

args[1] = args[1] and args[1]:lower() -- check for no args, lower command

if args[1] == "lock" then
    shell.run("startup")
elseif args[1] == "adduser" and args[2] and args[3] then
    local login = args[2]:lower():gsub("%s", "") -- Format user
    local pass = sha256.sha256(args[3]) -- Encode password

    local f = fs.open("login_users", "r") or error("Can not open file login_users! Please reboot!", 0)

    for token in string.gmatch(f.readAll(), "[^\n]+") do -- Check is user does not exist
        local p1, p2 = token:find(login)

        if p1 == 1 and p2 == #token then
            f.close()
            error("User "..login.." exists!", 0)
        end
    end

    f.close()

    -- Add users
    local f = fs.open("login_users", "a") or error("Can not open file login_users! Please reboot!", 0)
    f.writeLine(login)
    f.writeLine(pass)
    f.close()

    print("User "..login.." added!")
elseif args[1] == "deluser" and args[2] and args[3] then
    local login = args[2]:lower():gsub("%s", "") -- Format user
    local pass = sha256.sha256(args[3]) -- Encode password

    local f = fs.open("login_users", "r") or error("Can not open file login_users! Please reboot!", 0)
    local file = f.readAll()
    f.close()

    if file:find(login.."\n"..pass) == 1 then
        file = file:gsub(login.."\n"..pass, "")
    elseif file:find("\n"..login.."\n"..pass) then
        file = file:gsub("\n"..login.."\n"..pass, "")
    else
        error("Wrong user and password combo!", 0)
    end

    local f = fs.open("login_users", "w") or error("Can not open file login_users! Please reboot!", 0)
    f.write(file)
    f.close()

    print("User "..login.." deleted!")
elseif args[1] == "passwd" and args[2] and args[3] and args[4] then
    local login = args[2]:lower():gsub("%s", "") -- Format user
    local pass = sha256.sha256(args[3]) -- Encode password
    local npass = sha256.sha256(args[4]) -- Encode password

local f = fs.open("login_users", "r") or error("Can not open file login_users! Please reboot!", 0)
    local file = f.readAll()
    f.close()

    if file:find(login.."\n"..pass) == 1 then
        file = file:gsub(login.."\n"..pass, login.."\n"..npass)
    elseif file:find("\n"..login.."\n"..pass) then
        file = file:gsub("\n"..login.."\n"..pass, "\n"..login.."\n"..npass)
    else
        error("Wrong user and password combo!", 0)
    end

    local f = fs.open("login_users", "w") or error("Can not open file login_users! Please reboot!", 0)
    f.write(file)
    f.close()

    print("Password for user "..login.." changed!")
else
    usage()
end

os.unloadAPI("sha256")