robapi

function version()
  return 1.12
end

function explode(str, delimiter)
    local result = { }
    local from = 1
    local delim_from, delim_to = string.find( str, delimiter, from )
    while delim_from do
        table.insert( result, string.sub( str, from , delim_from-1 ) )
        from = delim_to + 1
        delim_from, delim_to = string.find( str, delimiter, from )
    end
    table.insert( result, string.sub( str, from ) )
    return result
end

--[[

  Misc. utility functions

]]

function randomOf(t)
    return t[math.random(1, #t)];
end

function applyToAll(fn, ...)
    local inp = {...};
    local out = {};
    for i=1,#inp do
      out[i]=fn(inp[i]);
    end
    return unpack(out);
end

function DEBUG_DUMP( t , fn, ... )
    if not fn then fn = print; end
    local msg = "";
    local ignore = {...};

    for k,v in pairs(t) do
      local vstr;
      if k==ign then
        vstr = "(ignored)";
      elseif v == t then
        vstr = "(SELF)";
      else
        vstr = type(v) == "table" and serializeTablePrettily(v, true, 2, 1, ...) or tostring(v);
      end
      msg = msg .. k .. "=" .. vstr .. "\n";
    end

    fn(msg);
end

function pad(str, length, lr, char) -- pads a string left/right with a character. lr:l/r/b
  if not str then error("pad: needs string input"); end
  str = tostring(str);
  char = char or " ";
  lr = lr:sub(1,1):lower();

  local pl = length - str:len();
  if pl < 0 then pl = 0; end

  local b = lr=="b";
  local l,r = (b or lr=="l"),(b or lr=="r");

  if b then pl = pl / 2; end

  local pad = char:rep(pl);
  return string.format("%s%s%s%s",
    "",
    l and pad or "", str,
    r and pad or "");
end

function clear() -- shorthand func for term.clear and cur reset
  term.clear(); term.setCursorPos(1,1);
end

function indexOf(tbl, v) -- simple utility function for reverse table lookup
    for k,w in pairs(tbl) do
        if v==w then return k; end
    end

    return false;
end

function countPairs(tbl)
    local n = 0;
    for k in pairs(tbl) do n = n + 1; end
    return n;
end

function getFile(file)
  local fh = fs.open(file, "r");
  if not fh then return false; end

  return textutils.unserialize( fh.readAll() );
end

function putFile(file, t)
  local fh = fs.open(file, "w");
  if not fh then return false; end

  fh.write( textutils.serialize(t) );
  fh.close();
  return true;
end

-- "pretty table serialization" (robhol)

function isTableEmpty(t)
    for k,v in pairs(t) do return false; end
    return true;
end

local function toexp(v)
    if type(v) == "string" then
        return "\"" .. tostring(v) .. "\"";
    end
    return tostring(v);
end

function serializeTablePrettily(tbl, includeKeys, inddepth, lvl, ...)

    local lvl = lvl or 1;
    local indent = " ";
    local inddepth = inddepth or 2;

    local ignore = {...};

    local str = indent:rep(inddepth * (lvl-1)) .. "{\n";

    for k, v in pairs(tbl) do

        local line = false;
        local newline = false;
        local t = type(v);

        if indexOf(ignore, k) then
          line = "(ignored)";
          error("ignored");
        end

        if t == "table" and not isTableEmpty(v) then
            line = serializeTablePrettily(v, includeKeys, inddepth, lvl+1);
            newline = true;
        else
            if t == "function" then
                --error("cannot serialize functions");
                line = "\"\" -- function skipped";
            elseif t == "table" then --empty!
                line = "{}";
            else
                line = toexp(v);
            end
        end

        line = indent:rep(inddepth * (lvl)) .. (includeKeys and "[" .. toexp(k) .. "] = " or "") .. (newline and "\n" or "") ..  line;
        str = str .. line .. ",\n";

    end

    return str:sub(1, #str-2) .. "\n" .. indent:rep(inddepth * (lvl-1)) .. "}"; --remove last comma and \n

end
--end of table serialization



--     getArgs - simplified argument handling (robhol)
--      usage: flags, args = getArgs({...}, "ab?c") - register flags a, b and c, b does not have a value (presence only)
--    program: prog -a 42 -b -c n 9001 9002
--              OR
--             prog -abc 42 n 9001 9002
--             > flags={a=42 b=true c="n") args={9001 9002}

function getArgs(xargs, sformat)

    local iargs, flags, rargs, poflags = {}, {}, {}, {};

    --duplicate the args table, we'll be playing rough with it
    --we'll also expand multiflags (-abc -> -a -b -c)
    for k, v in ipairs(xargs) do
        local mflag = v:match("-(%a+)");
        if mflag then
            for mf in mflag:gmatch("%a") do
                table.insert(iargs, "-" .. mf)
            end
        else
            table.insert(iargs, v);
        end
    end

    for fk, n in sformat:gmatch("(%a)(\??)") do
        if fk then
            poflags[fk] = (n=="?");
        end
    end

    while #iargs > 0 do
        local settingFlag = false;

        for k, v in ipairs(iargs) do
            local curFlag = v:match("-%a+");

            if not curFlag then
                if settingFlag then
                    --value and we're setting a flag! match!
                    flags[settingFlag:sub(2)] = v;
                    table.remove(iargs, k);
                    table.remove(iargs, indexOf(iargs, settingFlag));
                    settingFlag = false;
                    break;
                else
                    --value and no associated flag, put into rargs and fekkoff
                    table.remove(iargs, k);
                    table.insert(rargs, v);
                    break;
                end
            else
                if not settingFlag then
                    --flag and we're not currently setting one!

                    if poflags[curFlag:sub(2)] then --is this a "presence only" flag?
                        flags[curFlag:sub(2)] = true;
                        table.remove(iargs, k);
                        break;
                    else
                        settingFlag = curFlag;
                    end
                end
                --else: do nothing (ignore flags immediately after other flags)
            end

        end

        if settingFlag then
            flags[settingFlag] = true;
            table.remove(iargs, indexOf(iargs, settingFlag));
            settingFlag = false;
        end

    end

    return flags, rargs;
end

--END OF GETARGS

--table copying functions ninjaed from the lua wiki
-- http://lua-users.org/wiki/CopyTable
function shallowcopy(orig)
    local orig_type = type(orig)
    local copy
    if orig_type == 'table' then
        copy = {}
        for orig_key, orig_value in pairs(orig) do
            copy[orig_key] = orig_value
        end
    else -- number, string, boolean, etc
        copy = orig
    end
    return copy
end

function deepcopy(orig)
    local orig_type = type(orig)
    local copy
    if orig_type == 'table' then
        copy = {}
        for orig_key, orig_value in next, orig, nil do
            copy[deepcopy(orig_key)] = deepcopy(orig_value)
        end
        setmetatable(copy, deepcopy(getmetatable(orig)))
    else -- number, string, boolean, etc
        copy = orig
    end
    return copy
end


-- ARCFOUR implementation in pure Lua
-- Copyright 2008 Rob Kendrick <rjek@rjek.com>
-- Distributed under the MIT licence

local function make_byte_table(bits)
    local f = { }
    for i = 0, 255 do
        f[i] = { }
    end

    f[0][0] = bits[1] * 255

    local m = 1

    for k = 0, 7 do
        for i = 0, m - 1 do
            for j = 0, m - 1 do
                local fij = f[i][j] - bits[1] * m
                f[i  ][j+m] = fij + bits[2] * m
                f[i+m][j  ] = fij + bits[3] * m
                f[i+m][j+m] = fij + bits[4] * m
            end
        end
        m = m * 2
    end

    return f
end

local byte_xor = make_byte_table { 0, 1, 1, 0 }

local function generate(self, count)
    local S, i, j = self.S, self.i, self.j
    local o = { }
    local char = string.char

    for z = 1, count do
        i = (i + 1) % 256
        j = (j + S[i]) % 256
        S[i], S[j] = S[j], S[i]
        o[z] = char(S[(S[i] + S[j]) % 256])
    end

    self.i, self.j = i, j
    return table.concat(o)
end

local function cipher(self, plaintext)
    local pad = generate(self, #plaintext)
    local r = { }
    local byte = string.byte
    local char = string.char

    for i = 1, #plaintext do
        r[i] = char(byte_xor[byte(plaintext, i)][byte(pad, i)])
    end

    return table.concat(r)
end

local function schedule(self, key)
    local S = self.S
    local j, kz = 0, #key
    local byte = string.byte

    for i = 0, 255 do
        j = (j + S[i] + byte(key, (i % kz) + 1)) % 256;
        S[i], S[j] = S[j], S[i]
    end
end

local arcfour={};
arcfour.new = function (key)
    local S = { }
    local r = {
        S = S, i = 0, j = 0,
        generate = generate,
        cipher = cipher,
        schedule = schedule
    }

    for i = 0, 255 do
        S[i] = i
    end

    if key then
        r:schedule(key)
    end

    return r
end

function arc4(plain, key) -- simple wrapper (robhol)
    local state = arcfour.new(key);
    state:generate(3072);
    return state:cipher(plain);
end
-- END OF ARCFOUR

--[[
-- SHA-1 secure hash computation, and HMAC-SHA1 signature computation,
-- Latest version always at:  http://regex.info/blog/lua/sha1
--
-- Copyright 2009 Jeffrey Friedl
-- jfriedl@yahoo.com
-- http://regex.info/blog/

-- Version 1 [May 28, 2009]]

-- Return a W32 object for the number zero
local 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
local 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

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

   return W32
end

local 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

local 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

local 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

local 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

local 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

local 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

local 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",
}

local 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

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

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


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

local function hex_to_binary(hex)
   return hex:gsub('..', function(hexval)
                            return string.char(tonumber(hexval, 16))
                         end)
end

function sha1_binary(msg)
   return hex_to_binary(sha1(msg))
end

local xor_with_0x5c = {
   [string.char(  0)] = string.char( 92),   [string.char(  1)] = string.char( 93),
   [string.char(  2)] = string.char( 94),   [string.char(  3)] = string.char( 95),
   [string.char(  4)] = string.char( 88),   [string.char(  5)] = string.char( 89),
   [string.char(  6)] = string.char( 90),   [string.char(  7)] = string.char( 91),
   [string.char(  8)] = string.char( 84),   [string.char(  9)] = string.char( 85),
   [string.char( 10)] = string.char( 86),   [string.char( 11)] = string.char( 87),
   [string.char( 12)] = string.char( 80),   [string.char( 13)] = string.char( 81),
   [string.char( 14)] = string.char( 82),   [string.char( 15)] = string.char( 83),
   [string.char( 16)] = string.char( 76),   [string.char( 17)] = string.char( 77),
   [string.char( 18)] = string.char( 78),   [string.char( 19)] = string.char( 79),
   [string.char( 20)] = string.char( 72),   [string.char( 21)] = string.char( 73),
   [string.char( 22)] = string.char( 74),   [string.char( 23)] = string.char( 75),
   [string.char( 24)] = string.char( 68),   [string.char( 25)] = string.char( 69),
   [string.char( 26)] = string.char( 70),   [string.char( 27)] = string.char( 71),
   [string.char( 28)] = string.char( 64),   [string.char( 29)] = string.char( 65),
   [string.char( 30)] = string.char( 66),   [string.char( 31)] = string.char( 67),
   [string.char( 32)] = string.char(124),   [string.char( 33)] = string.char(125),
   [string.char( 34)] = string.char(126),   [string.char( 35)] = string.char(127),
   [string.char( 36)] = string.char(120),   [string.char( 37)] = string.char(121),
   [string.char( 38)] = string.char(122),   [string.char( 39)] = string.char(123),
   [string.char( 40)] = string.char(116),   [string.char( 41)] = string.char(117),
   [string.char( 42)] = string.char(118),   [string.char( 43)] = string.char(119),
   [string.char( 44)] = string.char(112),   [string.char( 45)] = string.char(113),
   [string.char( 46)] = string.char(114),   [string.char( 47)] = string.char(115),
   [string.char( 48)] = string.char(108),   [string.char( 49)] = string.char(109),
   [string.char( 50)] = string.char(110),   [string.char( 51)] = string.char(111),
   [string.char( 52)] = string.char(104),   [string.char( 53)] = string.char(105),
   [string.char( 54)] = string.char(106),   [string.char( 55)] = string.char(107),
   [string.char( 56)] = string.char(100),   [string.char( 57)] = string.char(101),
   [string.char( 58)] = string.char(102),   [string.char( 59)] = string.char(103),
   [string.char( 60)] = string.char( 96),   [string.char( 61)] = string.char( 97),
   [string.char( 62)] = string.char( 98),   [string.char( 63)] = string.char( 99),
   [string.char( 64)] = string.char( 28),   [string.char( 65)] = string.char( 29),
   [string.char( 66)] = string.char( 30),   [string.char( 67)] = string.char( 31),
   [string.char( 68)] = string.char( 24),   [string.char( 69)] = string.char( 25),
   [string.char( 70)] = string.char( 26),   [string.char( 71)] = string.char( 27),
   [string.char( 72)] = string.char( 20),   [string.char( 73)] = string.char( 21),
   [string.char( 74)] = string.char( 22),   [string.char( 75)] = string.char( 23),
   [string.char( 76)] = string.char( 16),   [string.char( 77)] = string.char( 17),
   [string.char( 78)] = string.char( 18),   [string.char( 79)] = string.char( 19),
   [string.char( 80)] = string.char( 12),   [string.char( 81)] = string.char( 13),
   [string.char( 82)] = string.char( 14),   [string.char( 83)] = string.char( 15),
   [string.char( 84)] = string.char(  8),   [string.char( 85)] = string.char(  9),
   [string.char( 86)] = string.char( 10),   [string.char( 87)] = string.char( 11),
   [string.char( 88)] = string.char(  4),   [string.char( 89)] = string.char(  5),
   [string.char( 90)] = string.char(  6),   [string.char( 91)] = string.char(  7),
   [string.char( 92)] = string.char(  0),   [string.char( 93)] = string.char(  1),
   [string.char( 94)] = string.char(  2),   [string.char( 95)] = string.char(  3),
   [string.char( 96)] = string.char( 60),   [string.char( 97)] = string.char( 61),
   [string.char( 98)] = string.char( 62),   [string.char( 99)] = string.char( 63),
   [string.char(100)] = string.char( 56),   [string.char(101)] = string.char( 57),
   [string.char(102)] = string.char( 58),   [string.char(103)] = string.char( 59),
   [string.char(104)] = string.char( 52),   [string.char(105)] = string.char( 53),
   [string.char(106)] = string.char( 54),   [string.char(107)] = string.char( 55),
   [string.char(108)] = string.char( 48),   [string.char(109)] = string.char( 49),
   [string.char(110)] = string.char( 50),   [string.char(111)] = string.char( 51),
   [string.char(112)] = string.char( 44),   [string.char(113)] = string.char( 45),
   [string.char(114)] = string.char( 46),   [string.char(115)] = string.char( 47),
   [string.char(116)] = string.char( 40),   [string.char(117)] = string.char( 41),
   [string.char(118)] = string.char( 42),   [string.char(119)] = string.char( 43),
   [string.char(120)] = string.char( 36),   [string.char(121)] = string.char( 37),
   [string.char(122)] = string.char( 38),   [string.char(123)] = string.char( 39),
   [string.char(124)] = string.char( 32),   [string.char(125)] = string.char( 33),
   [string.char(126)] = string.char( 34),   [string.char(127)] = string.char( 35),
   [string.char(128)] = string.char(220),   [string.char(129)] = string.char(221),
   [string.char(130)] = string.char(222),   [string.char(131)] = string.char(223),
   [string.char(132)] = string.char(216),   [string.char(133)] = string.char(217),
   [string.char(134)] = string.char(218),   [string.char(135)] = string.char(219),
   [string.char(136)] = string.char(212),   [string.char(137)] = string.char(213),
   [string.char(138)] = string.char(214),   [string.char(139)] = string.char(215),
   [string.char(140)] = string.char(208),   [string.char(141)] = string.char(209),
   [string.char(142)] = string.char(210),   [string.char(143)] = string.char(211),
   [string.char(144)] = string.char(204),   [string.char(145)] = string.char(205),
   [string.char(146)] = string.char(206),   [string.char(147)] = string.char(207),
   [string.char(148)] = string.char(200),   [string.char(149)] = string.char(201),
   [string.char(150)] = string.char(202),   [string.char(151)] = string.char(203),
   [string.char(152)] = string.char(196),   [string.char(153)] = string.char(197),
   [string.char(154)] = string.char(198),   [string.char(155)] = string.char(199),
   [string.char(156)] = string.char(192),   [string.char(157)] = string.char(193),
   [string.char(158)] = string.char(194),   [string.char(159)] = string.char(195),
   [string.char(160)] = string.char(252),   [string.char(161)] = string.char(253),
   [string.char(162)] = string.char(254),   [string.char(163)] = string.char(255),
   [string.char(164)] = string.char(248),   [string.char(165)] = string.char(249),
   [string.char(166)] = string.char(250),   [string.char(167)] = string.char(251),
   [string.char(168)] = string.char(244),   [string.char(169)] = string.char(245),
   [string.char(170)] = string.char(246),   [string.char(171)] = string.char(247),
   [string.char(172)] = string.char(240),   [string.char(173)] = string.char(241),
   [string.char(174)] = string.char(242),   [string.char(175)] = string.char(243),
   [string.char(176)] = string.char(236),   [string.char(177)] = string.char(237),
   [string.char(178)] = string.char(238),   [string.char(179)] = string.char(239),
   [string.char(180)] = string.char(232),   [string.char(181)] = string.char(233),
   [string.char(182)] = string.char(234),   [string.char(183)] = string.char(235),
   [string.char(184)] = string.char(228),   [string.char(185)] = string.char(229),
   [string.char(186)] = string.char(230),   [string.char(187)] = string.char(231),
   [string.char(188)] = string.char(224),   [string.char(189)] = string.char(225),
   [string.char(190)] = string.char(226),   [string.char(191)] = string.char(227),
   [string.char(192)] = string.char(156),   [string.char(193)] = string.char(157),
   [string.char(194)] = string.char(158),   [string.char(195)] = string.char(159),
   [string.char(196)] = string.char(152),   [string.char(197)] = string.char(153),
   [string.char(198)] = string.char(154),   [string.char(199)] = string.char(155),
   [string.char(200)] = string.char(148),   [string.char(201)] = string.char(149),
   [string.char(202)] = string.char(150),   [string.char(203)] = string.char(151),
   [string.char(204)] = string.char(144),   [string.char(205)] = string.char(145),
   [string.char(206)] = string.char(146),   [string.char(207)] = string.char(147),
   [string.char(208)] = string.char(140),   [string.char(209)] = string.char(141),
   [string.char(210)] = string.char(142),   [string.char(211)] = string.char(143),
   [string.char(212)] = string.char(136),   [string.char(213)] = string.char(137),
   [string.char(214)] = string.char(138),   [string.char(215)] = string.char(139),
   [string.char(216)] = string.char(132),   [string.char(217)] = string.char(133),
   [string.char(218)] = string.char(134),   [string.char(219)] = string.char(135),
   [string.char(220)] = string.char(128),   [string.char(221)] = string.char(129),
   [string.char(222)] = string.char(130),   [string.char(223)] = string.char(131),
   [string.char(224)] = string.char(188),   [string.char(225)] = string.char(189),
   [string.char(226)] = string.char(190),   [string.char(227)] = string.char(191),
   [string.char(228)] = string.char(184),   [string.char(229)] = string.char(185),
   [string.char(230)] = string.char(186),   [string.char(231)] = string.char(187),
   [string.char(232)] = string.char(180),   [string.char(233)] = string.char(181),
   [string.char(234)] = string.char(182),   [string.char(235)] = string.char(183),
   [string.char(236)] = string.char(176),   [string.char(237)] = string.char(177),
   [string.char(238)] = string.char(178),   [string.char(239)] = string.char(179),
   [string.char(240)] = string.char(172),   [string.char(241)] = string.char(173),
   [string.char(242)] = string.char(174),   [string.char(243)] = string.char(175),
   [string.char(244)] = string.char(168),   [string.char(245)] = string.char(169),
   [string.char(246)] = string.char(170),   [string.char(247)] = string.char(171),
   [string.char(248)] = string.char(164),   [string.char(249)] = string.char(165),
   [string.char(250)] = string.char(166),   [string.char(251)] = string.char(167),
   [string.char(252)] = string.char(160),   [string.char(253)] = string.char(161),
   [string.char(254)] = string.char(162),   [string.char(255)] = string.char(163),
}

local xor_with_0x36 = {
   [string.char(  0)] = string.char( 54),   [string.char(  1)] = string.char( 55),
   [string.char(  2)] = string.char( 52),   [string.char(  3)] = string.char( 53),
   [string.char(  4)] = string.char( 50),   [string.char(  5)] = string.char( 51),
   [string.char(  6)] = string.char( 48),   [string.char(  7)] = string.char( 49),
   [string.char(  8)] = string.char( 62),   [string.char(  9)] = string.char( 63),
   [string.char( 10)] = string.char( 60),   [string.char( 11)] = string.char( 61),
   [string.char( 12)] = string.char( 58),   [string.char( 13)] = string.char( 59),
   [string.char( 14)] = string.char( 56),   [string.char( 15)] = string.char( 57),
   [string.char( 16)] = string.char( 38),   [string.char( 17)] = string.char( 39),
   [string.char( 18)] = string.char( 36),   [string.char( 19)] = string.char( 37),
   [string.char( 20)] = string.char( 34),   [string.char( 21)] = string.char( 35),
   [string.char( 22)] = string.char( 32),   [string.char( 23)] = string.char( 33),
   [string.char( 24)] = string.char( 46),   [string.char( 25)] = string.char( 47),
   [string.char( 26)] = string.char( 44),   [string.char( 27)] = string.char( 45),
   [string.char( 28)] = string.char( 42),   [string.char( 29)] = string.char( 43),
   [string.char( 30)] = string.char( 40),   [string.char( 31)] = string.char( 41),
   [string.char( 32)] = string.char( 22),   [string.char( 33)] = string.char( 23),
   [string.char( 34)] = string.char( 20),   [string.char( 35)] = string.char( 21),
   [string.char( 36)] = string.char( 18),   [string.char( 37)] = string.char( 19),
   [string.char( 38)] = string.char( 16),   [string.char( 39)] = string.char( 17),
   [string.char( 40)] = string.char( 30),   [string.char( 41)] = string.char( 31),
   [string.char( 42)] = string.char( 28),   [string.char( 43)] = string.char( 29),
   [string.char( 44)] = string.char( 26),   [string.char( 45)] = string.char( 27),
   [string.char( 46)] = string.char( 24),   [string.char( 47)] = string.char( 25),
   [string.char( 48)] = string.char(  6),   [string.char( 49)] = string.char(  7),
   [string.char( 50)] = string.char(  4),   [string.char( 51)] = string.char(  5),
   [string.char( 52)] = string.char(  2),   [string.char( 53)] = string.char(  3),
   [string.char( 54)] = string.char(  0),   [string.char( 55)] = string.char(  1),
   [string.char( 56)] = string.char( 14),   [string.char( 57)] = string.char( 15),
   [string.char( 58)] = string.char( 12),   [string.char( 59)] = string.char( 13),
   [string.char( 60)] = string.char( 10),   [string.char( 61)] = string.char( 11),
   [string.char( 62)] = string.char(  8),   [string.char( 63)] = string.char(  9),
   [string.char( 64)] = string.char(118),   [string.char( 65)] = string.char(119),
   [string.char( 66)] = string.char(116),   [string.char( 67)] = string.char(117),
   [string.char( 68)] = string.char(114),   [string.char( 69)] = string.char(115),
   [string.char( 70)] = string.char(112),   [string.char( 71)] = string.char(113),
   [string.char( 72)] = string.char(126),   [string.char( 73)] = string.char(127),
   [string.char( 74)] = string.char(124),   [string.char( 75)] = string.char(125),
   [string.char( 76)] = string.char(122),   [string.char( 77)] = string.char(123),
   [string.char( 78)] = string.char(120),   [string.char( 79)] = string.char(121),
   [string.char( 80)] = string.char(102),   [string.char( 81)] = string.char(103),
   [string.char( 82)] = string.char(100),   [string.char( 83)] = string.char(101),
   [string.char( 84)] = string.char( 98),   [string.char( 85)] = string.char( 99),
   [string.char( 86)] = string.char( 96),   [string.char( 87)] = string.char( 97),
   [string.char( 88)] = string.char(110),   [string.char( 89)] = string.char(111),
   [string.char( 90)] = string.char(108),   [string.char( 91)] = string.char(109),
   [string.char( 92)] = string.char(106),   [string.char( 93)] = string.char(107),
   [string.char( 94)] = string.char(104),   [string.char( 95)] = string.char(105),
   [string.char( 96)] = string.char( 86),   [string.char( 97)] = string.char( 87),
   [string.char( 98)] = string.char( 84),   [string.char( 99)] = string.char( 85),
   [string.char(100)] = string.char( 82),   [string.char(101)] = string.char( 83),
   [string.char(102)] = string.char( 80),   [string.char(103)] = string.char( 81),
   [string.char(104)] = string.char( 94),   [string.char(105)] = string.char( 95),
   [string.char(106)] = string.char( 92),   [string.char(107)] = string.char( 93),
   [string.char(108)] = string.char( 90),   [string.char(109)] = string.char( 91),
   [string.char(110)] = string.char( 88),   [string.char(111)] = string.char( 89),
   [string.char(112)] = string.char( 70),   [string.char(113)] = string.char( 71),
   [string.char(114)] = string.char( 68),   [string.char(115)] = string.char( 69),
   [string.char(116)] = string.char( 66),   [string.char(117)] = string.char( 67),
   [string.char(118)] = string.char( 64),   [string.char(119)] = string.char( 65),
   [string.char(120)] = string.char( 78),   [string.char(121)] = string.char( 79),
   [string.char(122)] = string.char( 76),   [string.char(123)] = string.char( 77),
   [string.char(124)] = string.char( 74),   [string.char(125)] = string.char( 75),
   [string.char(126)] = string.char( 72),   [string.char(127)] = string.char( 73),
   [string.char(128)] = string.char(182),   [string.char(129)] = string.char(183),
   [string.char(130)] = string.char(180),   [string.char(131)] = string.char(181),
   [string.char(132)] = string.char(178),   [string.char(133)] = string.char(179),
   [string.char(134)] = string.char(176),   [string.char(135)] = string.char(177),
   [string.char(136)] = string.char(190),   [string.char(137)] = string.char(191),
   [string.char(138)] = string.char(188),   [string.char(139)] = string.char(189),
   [string.char(140)] = string.char(186),   [string.char(141)] = string.char(187),
   [string.char(142)] = string.char(184),   [string.char(143)] = string.char(185),
   [string.char(144)] = string.char(166),   [string.char(145)] = string.char(167),
   [string.char(146)] = string.char(164),   [string.char(147)] = string.char(165),
   [string.char(148)] = string.char(162),   [string.char(149)] = string.char(163),
   [string.char(150)] = string.char(160),   [string.char(151)] = string.char(161),
   [string.char(152)] = string.char(174),   [string.char(153)] = string.char(175),
   [string.char(154)] = string.char(172),   [string.char(155)] = string.char(173),
   [string.char(156)] = string.char(170),   [string.char(157)] = string.char(171),
   [string.char(158)] = string.char(168),   [string.char(159)] = string.char(169),
   [string.char(160)] = string.char(150),   [string.char(161)] = string.char(151),
   [string.char(162)] = string.char(148),   [string.char(163)] = string.char(149),
   [string.char(164)] = string.char(146),   [string.char(165)] = string.char(147),
   [string.char(166)] = string.char(144),   [string.char(167)] = string.char(145),
   [string.char(168)] = string.char(158),   [string.char(169)] = string.char(159),
   [string.char(170)] = string.char(156),   [string.char(171)] = string.char(157),
   [string.char(172)] = string.char(154),   [string.char(173)] = string.char(155),
   [string.char(174)] = string.char(152),   [string.char(175)] = string.char(153),
   [string.char(176)] = string.char(134),   [string.char(177)] = string.char(135),
   [string.char(178)] = string.char(132),   [string.char(179)] = string.char(133),
   [string.char(180)] = string.char(130),   [string.char(181)] = string.char(131),
   [string.char(182)] = string.char(128),   [string.char(183)] = string.char(129),
   [string.char(184)] = string.char(142),   [string.char(185)] = string.char(143),
   [string.char(186)] = string.char(140),   [string.char(187)] = string.char(141),
   [string.char(188)] = string.char(138),   [string.char(189)] = string.char(139),
   [string.char(190)] = string.char(136),   [string.char(191)] = string.char(137),
   [string.char(192)] = string.char(246),   [string.char(193)] = string.char(247),
   [string.char(194)] = string.char(244),   [string.char(195)] = string.char(245),
   [string.char(196)] = string.char(242),   [string.char(197)] = string.char(243),
   [string.char(198)] = string.char(240),   [string.char(199)] = string.char(241),
   [string.char(200)] = string.char(254),   [string.char(201)] = string.char(255),
   [string.char(202)] = string.char(252),   [string.char(203)] = string.char(253),
   [string.char(204)] = string.char(250),   [string.char(205)] = string.char(251),
   [string.char(206)] = string.char(248),   [string.char(207)] = string.char(249),
   [string.char(208)] = string.char(230),   [string.char(209)] = string.char(231),
   [string.char(210)] = string.char(228),   [string.char(211)] = string.char(229),
   [string.char(212)] = string.char(226),   [string.char(213)] = string.char(227),
   [string.char(214)] = string.char(224),   [string.char(215)] = string.char(225),
   [string.char(216)] = string.char(238),   [string.char(217)] = string.char(239),
   [string.char(218)] = string.char(236),   [string.char(219)] = string.char(237),
   [string.char(220)] = string.char(234),   [string.char(221)] = string.char(235),
   [string.char(222)] = string.char(232),   [string.char(223)] = string.char(233),
   [string.char(224)] = string.char(214),   [string.char(225)] = string.char(215),
   [string.char(226)] = string.char(212),   [string.char(227)] = string.char(213),
   [string.char(228)] = string.char(210),   [string.char(229)] = string.char(211),
   [string.char(230)] = string.char(208),   [string.char(231)] = string.char(209),
   [string.char(232)] = string.char(222),   [string.char(233)] = string.char(223),
   [string.char(234)] = string.char(220),   [string.char(235)] = string.char(221),
   [string.char(236)] = string.char(218),   [string.char(237)] = string.char(219),
   [string.char(238)] = string.char(216),   [string.char(239)] = string.char(217),
   [string.char(240)] = string.char(198),   [string.char(241)] = string.char(199),
   [string.char(242)] = string.char(196),   [string.char(243)] = string.char(197),
   [string.char(244)] = string.char(194),   [string.char(245)] = string.char(195),
   [string.char(246)] = string.char(192),   [string.char(247)] = string.char(193),
   [string.char(248)] = string.char(206),   [string.char(249)] = string.char(207),
   [string.char(250)] = string.char(204),   [string.char(251)] = string.char(205),
   [string.char(252)] = string.char(202),   [string.char(253)] = string.char(203),
   [string.char(254)] = string.char(200),   [string.char(255)] = string.char(201),
}


local blocksize = 64 -- 512 bits

function hmac_sha1(key, text)
   assert(type(key)  == 'string', "key passed to hmac_sha1 should be a string")
   assert(type(text) == 'string', "text passed to hmac_sha1 should be a string")

   if #key > blocksize then
      key = sha1_binary(key)
   end

   local key_xord_with_0x36 = key:gsub('.', xor_with_0x36) .. string.rep(string.char(0x36), blocksize - #key)
   local key_xord_with_0x5c = key:gsub('.', xor_with_0x5c) .. string.rep(string.char(0x5c), blocksize - #key)

   return sha1(key_xord_with_0x5c .. sha1_binary(key_xord_with_0x36 .. text))
end

function hmac_sha1_binary(key, text)
   return hex_to_binary(hmac_sha1(key, text))
end
--END OF SHA1