CraftyComputer

--[[
   _____            __ _          _____                            _
  / ____|          / _| |        / ____|                          | |
 | |     _ __ __ _| |_| |_ _   _| |     ___  _ __ ___  _ __  _   _| |_ ___ _ __
 | |    | '__/ _` |  _| __| | | | |    / _ \| '_ ` _ \| '_ \| | | | __/ _ \ '__|
 | |____| | | (_| | | | |_| |_| | |___| (_) | | | | | | |_) | |_| | ||  __/ |
  \_____|_|  \__,_|_|  \__|\__, |\_____\___/|_| |_| |_| .__/ \__,_|\__\___|_|
                            __/ |                     | |
                           |___/                      |_|
]]--

--Created by Anonomit


local sDir = "craftycomputer"


local sPassword
local tHistory = {}
local tPrograms = { "clear", "exit", "help", "id", "programs", "reboot", "shell", "shutdown", "time" }
local ZERO, hex_to_bits, from_hex, COPY, ADD, XOR, AND, OR, OR3, NOT, ROTATE, asHEX, sha1



do --[[SHA1 HASHING FUNCTIONS]]--

    do --[[NOTICE]]--
    --[[

        This SHA1 algorithm was created by Jeffrey Friedl.
        Code can be found online at
        http://regex.info/code/sha1.lua

    ]]--
    end --[[END NOTICE]]--

    do --[[HOW TO USE]]--
    --[[

        local hash_as_hex   = sha1(message)            -- returns a hex string
        local hash_as_data  = sha1_binary(message)     -- returns raw bytes
        --
        local hmac_as_hex   = hmac_sha1(key, message)        -- hex string
        local hmac_as_data  = hmac_sha1_binary(key, message) -- raw bytes

    ]]--
    end --[[END HOW TO USE]]--

    do --[[SHA1 HELPER FUNCTIONS]]--

        function ZERO()
           return {
              false, false, false, false,     false, false, false, false,
              false, false, false, false,     false, false, false, false,
              false, false, false, false,     false, false, false, false,
              false, false, false, false,     false, false, false, false,
           }
        end

        local hex_to_bits = {
           ["0"] = { false, false, false, false },
           ["1"] = { false, false, false, true  },
           ["2"] = { false, false, true,  false },
           ["3"] = { false, false, true,  true  },

           ["4"] = { false, true,  false, false },
           ["5"] = { false, true,  false, true  },
           ["6"] = { false, true,  true,  false },
           ["7"] = { false, true,  true,  true  },

           ["8"] = { true,  false, false, false },
           ["9"] = { true,  false, false, true  },
           ["A"] = { true,  false, true,  false },
           ["B"] = { true,  false, true,  true  },

           ["C"] = { true,  true,  false, false },
           ["D"] = { true,  true,  false, true  },
           ["E"] = { true,  true,  true,  false },
           ["F"] = { true,  true,  true,  true  },

           ["a"] = { true,  false, true,  false },
           ["b"] = { true,  false, true,  true  },
           ["c"] = { true,  true,  false, false },
           ["d"] = { true,  true,  false, true  },
           ["e"] = { true,  true,  true,  false },
           ["f"] = { true,  true,  true,  true  },
        }

        --
        -- Given a string of 8 hex digits, return a W32 object representing that number
        --
        function from_hex(hex)

           assert(type(hex) == 'string')
           assert(hex:match('^[0123456789abcdefABCDEF]+$'))
           assert(#hex == 8)

           local W32 = { }

           for letter in hex:gmatch('.') do
              local b = hex_to_bits[letter]
              assert(b)
              table.insert(W32, 1, b[1])
              table.insert(W32, 1, b[2])
              table.insert(W32, 1, b[3])
              table.insert(W32, 1, b[4])
           end

           return W32
        end

        function COPY(old)
           local W32 = { }
           for k,v in pairs(old) do
              W32[k] = v
           end

           return W32
        end

        function ADD(first, ...)

           local a = COPY(first)

           local C, b, sum

           for v = 1, select('#', ...) do
              b = select(v, ...)
              C = 0

              for i = 1, #a do
                 sum = (a[i] and 1 or 0)
                     + (b[i] and 1 or 0)
                     + C

                 if sum == 0 then
                    a[i] = false
                    C    = 0
                 elseif sum == 1 then
                    a[i] = true
                    C    = 0
                 elseif sum == 2 then
                    a[i] = false
                    C    = 1
                 else
                    a[i] = true
                    C    = 1
                 end
              end
              -- we drop any ending carry

           end

           return a
        end

        function XOR(first, ...)

           local a = COPY(first)
           local b
           for v = 1, select('#', ...) do
              b = select(v, ...)
              for i = 1, #a do
                 a[i] = a[i] ~= b[i]
              end
           end

           return a

        end

        function AND(a, b)

           local c = ZERO()

           for i = 1, #a do
              -- only need to set true bits; other bits remain false
              if  a[i] and b[i] then
                 c[i] = true
              end
           end

           return c
        end

        function OR(a, b)

           local c = ZERO()

           for i = 1, #a do
              -- only need to set true bits; other bits remain false
              if  a[i] or b[i] then
                 c[i] = true
              end
           end

           return c
        end

        function OR3(a, b, c)

           local d = ZERO()

           for i = 1, #a do
              -- only need to set true bits; other bits remain false
              if a[i] or b[i] or c[i] then
                 d[i] = true
              end
           end

           return d
        end

        function NOT(a)

           local b = ZERO()

           for i = 1, #a do
              -- only need to set true bits; other bits remain false
              if not a[i] then
                 b[i] = true
              end
           end

           return b
        end

        function ROTATE(bits, a)

           local b = COPY(a)

           while bits > 0 do
              bits = bits - 1
              table.insert(b, 1, table.remove(b))
           end

           return b

        end


        local binary_to_hex = {
           ["0000"] = "0",
           ["0001"] = "1",
           ["0010"] = "2",
           ["0011"] = "3",
           ["0100"] = "4",
           ["0101"] = "5",
           ["0110"] = "6",
           ["0111"] = "7",
           ["1000"] = "8",
           ["1001"] = "9",
           ["1010"] = "a",
           ["1011"] = "b",
           ["1100"] = "c",
           ["1101"] = "d",
           ["1110"] = "e",
           ["1111"] = "f",
        }

        function asHEX(a)

           local hex = ""
           local i = 1
           while i < #a do
              local binary = (a[i + 3] and '1' or '0')
                             ..
                             (a[i + 2] and '1' or '0')
                             ..
                             (a[i + 1] and '1' or '0')
                             ..
                             (a[i + 0] and '1' or '0')

              hex = binary_to_hex[binary] .. hex

              i = i + 4
           end

           return hex

        end

        x67452301 = from_hex("67452301")
        xEFCDAB89 = from_hex("EFCDAB89")
        x98BADCFE = from_hex("98BADCFE")
        x10325476 = from_hex("10325476")
        xC3D2E1F0 = from_hex("C3D2E1F0")

        x5A827999 = from_hex("5A827999")
        x6ED9EBA1 = from_hex("6ED9EBA1")
        x8F1BBCDC = from_hex("8F1BBCDC")
        xCA62C1D6 = from_hex("CA62C1D6")

    end --[[END SHA1 HELPER FUNCTIONS]]--

    do --[[MAIN SHA1 FUNCTIONS]]--

        function sha1(msg)

           assert(type(msg) == 'string')
           assert(#msg < 0x7FFFFFFF) -- have no idea what would happen if it were large

           local H0 = x67452301
           local H1 = xEFCDAB89
           local H2 = x98BADCFE
           local H3 = x10325476
           local H4 = xC3D2E1F0

           local msg_len_in_bits = #msg * 8

           local first_append = string.char(0x80) -- append a '1' bit plus seven '0' bits

           local non_zero_message_bytes = #msg +1 +8 -- the +1 is the appended bit 1, the +8 are for the final appended length
           local current_mod = non_zero_message_bytes % 64
           local second_append = ""
           if current_mod ~= 0 then
              second_append = string.rep(string.char(0), 64 - current_mod)
           end

           -- now to append the length as a 64-bit number.
           local B1, R1 = math.modf(msg_len_in_bits  / 0x01000000)
           local B2, R2 = math.modf( 0x01000000 * R1 / 0x00010000)
           local B3, R3 = math.modf( 0x00010000 * R2 / 0x00000100)
           local B4     =            0x00000100 * R3

           local L64 = string.char( 0) .. string.char( 0) .. string.char( 0) .. string.char( 0) -- high 32 bits
                    .. string.char(B1) .. string.char(B2) .. string.char(B3) .. string.char(B4) --  low 32 bits



           msg = msg .. first_append .. second_append .. L64

           assert(#msg % 64 == 0)

           --local fd = io.open("/tmp/msg", "wb")
           --fd:write(msg)
           --fd:close()

           local chunks = #msg / 64

           local W = { }
           local start, A, B, C, D, E, f, K, TEMP
           local chunk = 0

           while chunk < chunks do
              --
              -- break chunk up into W[0] through W[15]
              --
              start = chunk * 64 + 1
              chunk = chunk + 1

              for t = 0, 15 do
                 W[t] = from_hex(string.format("%02x%02x%02x%02x", msg:byte(start, start + 3)))
                 start = start + 4
              end

              --
              -- build W[16] through W[79]
              --
              for t = 16, 79 do
                 -- For t = 16 to 79 let Wt = S1(Wt-3 XOR Wt-8 XOR Wt-14 XOR Wt-16).
                 W[t] = ROTATE(1, XOR(W[t-3], W[t-8], W[t-14], W[t-16]))
              end

              A = H0
              B = H1
              C = H2
              D = H3
              E = H4

              for t = 0, 79 do
                 if t <= 19 then
                    -- (B AND C) OR ((NOT B) AND D)
                    f = OR(AND(B, C), AND(NOT(B), D))
                    K = x5A827999
                 elseif t <= 39 then
                    -- B XOR C XOR D
                    f = XOR(B, C, D)
                    K = x6ED9EBA1
                 elseif t <= 59 then
                    -- (B AND C) OR (B AND D) OR (C AND D
                    f = OR3(AND(B, C), AND(B, D), AND(C, D))
                    K = x8F1BBCDC
                 else
                    -- B XOR C XOR D
                    f = XOR(B, C, D)
                    K = xCA62C1D6
                 end

                 -- TEMP = S5(A) + ft(B,C,D) + E + Wt + Kt;
                 TEMP = ADD(ROTATE(5, A), f, E, W[t], K)

                 --E = D;   D = C;    C = S30(B);   B = A;   A = TEMP;
                 E = D
                 D = C
                 C = ROTATE(30, B)
                 B = A
                 A = TEMP

                 --printf("t = %2d: %s  %s  %s  %s  %s", t, A:HEX(), B:HEX(), C:HEX(), D:HEX(), E:HEX())
              end

              -- Let H0 = H0 + A, H1 = H1 + B, H2 = H2 + C, H3 = H3 + D, H4 = H4 + E.
              H0 = ADD(H0, A)
              H1 = ADD(H1, B)
              H2 = ADD(H2, C)
              H3 = ADD(H3, D)
              H4 = ADD(H4, E)
           end

           return asHEX(H0) .. asHEX(H1) .. asHEX(H2) .. asHEX(H3) .. asHEX(H4)
        end

    end --[[END MAIN SHA1 FUNCTIONS]]--

end --[[END SHA1 HASHING FUNCTIONS]]--



local function fColor( _nColor )
    if term.isColor ~= nil then
        if term.isColor() then
            term.setTextColor( _nColor )
        end --if term.isColor()
    end --if term.isColor ~= nil
end --local function fColor( _nColor )


term.clear()
term.setCursorPos( 1, 1 )

if not fs.isDir( "craftycomputer" ) then
    fs.makeDir( "craftycomputer" )
end --if not fs.isDir( "craftycomputer" )

if fs.exists( fs.combine( sDir, "password" ) ) then
    local file = fs.open( fs.combine( sDir, "password" ), "r" )
    sPassword = file.readLine()
    file.close()
else --fs.exists( fs.combine( sDir, "password" ) )
    fColor( 2 ^ math.random( 1, 14 ) )
    print( "CraftyComputer" )
    local sV0, sV1
    while true do
        term.setCursorPos( 1, 4 )
        term.clearLine()
        term.setCursorPos( 1, 3 )
        term.clearLine()
        fColor( colors.yellow )
        write( "Set The Password: " )
        fColor( colors.white )
        sV0 = read( "*" )
        fColor( colors.yellow )
        write( "Confirm Password: " )
        fColor( colors.white )
        sV1 = read( "*" )
        if sV0 == sV1 then
            break --while true
        end --if sV0 == sV1
    end --while true

    local file = fs.open( fs.combine( sDir, "password" ), "w" )
    sPassword = sha1( sV0 )
    file.writeLine( sPassword )
    file.close()

end --if fs.exists( fs.combine( sDir, "craftycomputer" ) )


local oldPullEvent = os.pullEvent
os.pullEvent = os.pullEventRaw


term.clear()
term.setCursorPos( 1, 1 )
fColor( colors.yellow )
print( os.version() )

local function fConsole()

    while true do

        fColor( colors.yellow )
        write( "> " )
        fColor( colors.white )
        local sInput = read( nil, tHistory )
        table.insert( tHistory, sInput )

        if sha1( sInput ) == sPassword then
            return
        end --if sha1( sInput ) == sPassword

        local sInput = string.sub( string.lower( sInput:match( "^%s*(.-)%s*$" ) ), string.find( string.lower( sInput:match( "^%s*(.-)%s*$" ) ), "(%S*)" ) )

        if sInput == "programs" then
            textutils.pagedTabulate( tPrograms )
        elseif sInput == "clear" then
            term.clear()
            term.setCursorPos( 1, 1 )
        elseif sInput == "help" then
            print( "No help available" )
        elseif sInput == "id" then
            print( "This is computer #" .. os.computerID() )
        elseif sInput == "shell" then
            fColor( colors.yellow )
            print( os.version() )
        elseif sInput == "time" then
            print( "The time is " .. textutils.formatTime( os.time(), false ) .. " on Day " .. os.day() )
        elseif sInput == "reboot" or sInput == "shutdown" or sInput == "exit" then
            fColor( colors.yellow )
            print( "Goodbye" )
            fColor( colors.white )
            local foo = sInput ~= "exit" and ( function() sleep( 1 ) return true end )() or os.shutdown()
            local foo = sInput == "reboot" and os.reboot() or os.shutdown()

        elseif sInput ~= "" then
            fColor( colors.red )
            print( "No such program" )
        end --if sInput == "programs"

    end --while true

end --local function fConsole()


local function fTerminate()

    os.pullEvent( "terminate" )

end --local function fTerminate()


if parallel.waitForAny( fConsole, fTerminate ) == 1 then
    fColor( 2 ^ math.random( 1, 14 ) )
    print( "Exiting CraftyComputer..." )
    os.pullEvent = oldPullEvent
    sleep( 1 )
    term.clear()
    term.setCursorPos( 1, 1 )
    fColor( colors.yellow )
    print( os.version() )
else --parallel.waitForAny( fConsole, fTerminate ) == 1
    fColor( colors.red )
    print( "Terminated" )
    fColor( colors.white )
    term.setCursorBlink( false )
    print( "Press any key to continue" )
    os.pullEvent = oldPullEvent
    os.pullEvent( "key" )
    os.shutdown()
end --if parallel.waitForAny( fConsole, fTerminate ) == 1