initial commit

MIT-LICENSE.txt

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+Copyright (c) 2013 Enrique García Cota + Eike Decker + Jeffrey Friedl
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

sha1.lua

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+-------------------------------------------------------------------------------
+-- SHA-1 secure hash computation, and HMAC-SHA1 signature computation in Lua (5.1)
+--
+-- This is a cleanup of Eike Decker - http://cube3d.de/uploads/Main/sha1.txt,
+-- which was based on an initial work by Jeffrey Friedl - http://regex.info/blog/lua/sha1
+--
+-- The implemented algorithm is http://www.itl.nist.gov/fipspubs/fip180-1.htm
+--
+-- License: MIT
+--
+-- Usage:
+--   local sha1 = require 'sha1'
+--
+--   local hash_as_hex   = sha1(message)            -- returns a hex string
+--   local hash_as_data  = sha1.binary(message)     -- returns raw bytes
+--
+--   local hmac_as_hex   = sha1.hmac(key, message)        -- hex string
+--   local hmac_as_data  = sha1.hmac_binary(key, message) -- raw bytes
+-------------------------------------------------------------------------------
+
+-- set this to false if you don't want to build several 64k sized tables when
+-- loading this file (takes a while but grants a boost of factor 13)
+local PRELOAD_CACHE = true
+
+local BLOCK_SIZE = 64 -- 512 bits
+
+-- local storing of global functions (minor speedup)
+local floor,modf = math.floor,math.modf
+local char,format,rep = string.char,string.format,string.rep
+
+-- merge 4 bytes to an 32 bit word
+local function bytes_to_w32(a,b,c,d) return a*0x1000000+b*0x10000+c*0x100+d end
+-- split a 32 bit word into four 8 bit numbers
+local function w32_to_bytes(i)
+  return floor(i/0x1000000)%0x100,floor(i/0x10000)%0x100,floor(i/0x100)%0x100,i%0x100
+end
+
+-- shift the bits of a 32 bit word. Don't use negative values for "bits"
+local function w32_rot(bits,a)
+  local b2 = 2^(32-bits)
+  local a,b = modf(a/b2)
+  return a+b*b2*(2^(bits))
+end
+
+-- caching function for functions that accept 2 arguments, both of values between
+-- 0 and 255. The function to be cached is passed, all values are calculated
+-- during loading and a function is returned that returns the cached values (only)
+local function cache2arg(fn)
+  if not PRELOAD_CACHE then return fn end
+  local lut = {}
+  for i=0,0xffff do
+    local a,b = floor(i/0x100),i%0x100
+    lut[i] = fn(a,b)
+  end
+  return function(a,b)
+    return lut[a*0x100+b]
+  end
+end
+
+-- splits an 8-bit number into 8 bits, returning all 8 bits as booleans
+local function byte_to_bits(b)
+  local b = function(n)
+    local b = floor(b/n)
+    return b%2==1
+  end
+  return b(1),b(2),b(4),b(8),b(16),b(32),b(64),b(128)
+end
+
+-- builds an 8bit number from 8 booleans
+local function bits_to_byte(a,b,c,d,e,f,g,h)
+  local function n(b,x) return b and x or 0 end
+  return n(a,1)+n(b,2)+n(c,4)+n(d,8)+n(e,16)+n(f,32)+n(g,64)+n(h,128)
+end
+
+-- bitwise "and" function for 2 8bit number
+local band = cache2arg (function(a,b)
+  local A,B,C,D,E,F,G,H = byte_to_bits(b)
+  local a,b,c,d,e,f,g,h = byte_to_bits(a)
+  return bits_to_byte(
+    A and a, B and b, C and c, D and d,
+    E and e, F and f, G and g, H and h)
+end)
+
+-- bitwise "or" function for 2 8bit numbers
+local bor = cache2arg(function(a,b)
+  local A,B,C,D,E,F,G,H = byte_to_bits(b)
+  local a,b,c,d,e,f,g,h = byte_to_bits(a)
+  return bits_to_byte(
+    A or a, B or b, C or c, D or d,
+    E or e, F or f, G or g, H or h)
+end)
+
+-- bitwise "xor" function for 2 8bit numbers
+local bxor = cache2arg(function(a,b)
+  local A,B,C,D,E,F,G,H = byte_to_bits(b)
+  local a,b,c,d,e,f,g,h = byte_to_bits(a)
+  return bits_to_byte(
+    A ~= a, B ~= b, C ~= c, D ~= d,
+    E ~= e, F ~= f, G ~= g, H ~= h)
+end)
+
+-- bitwise complement for one 8bit number
+local function bnot(x)
+  return 255-(x % 256)
+end
+
+-- creates a function to combine to 32bit numbers using an 8bit combination function
+local function w32_comb(fn)
+  return function(a,b)
+    local aa,ab,ac,ad = w32_to_bytes(a)
+    local ba,bb,bc,bd = w32_to_bytes(b)
+    return bytes_to_w32(fn(aa,ba),fn(ab,bb),fn(ac,bc),fn(ad,bd))
+  end
+end
+
+-- create functions for and, xor and or, all for 2 32bit numbers
+local w32_and = w32_comb(band)
+local w32_xor = w32_comb(bxor)
+local w32_or = w32_comb(bor)
+
+-- xor function that may receive a variable number of arguments
+local function w32_xor_n(a,...)
+  local aa,ab,ac,ad = w32_to_bytes(a)
+  for i=1,select('#',...) do
+    local ba,bb,bc,bd = w32_to_bytes(select(i,...))
+    aa,ab,ac,ad = bxor(aa,ba),bxor(ab,bb),bxor(ac,bc),bxor(ad,bd)
+  end
+  return bytes_to_w32(aa,ab,ac,ad)
+end
+
+-- combining 3 32bit numbers through binary "or" operation
+local function w32_or3(a,b,c)
+  local aa,ab,ac,ad = w32_to_bytes(a)
+  local ba,bb,bc,bd = w32_to_bytes(b)
+  local ca,cb,cc,cd = w32_to_bytes(c)
+  return bytes_to_w32(
+    bor(aa,bor(ba,ca)), bor(ab,bor(bb,cb)), bor(ac,bor(bc,cc)), bor(ad,bor(bd,cd))
+  )
+end
+
+-- binary complement for 32bit numbers
+local function w32_not(a)
+  return 4294967295-(a % 4294967296)
+end
+
+-- adding 2 32bit numbers, cutting off the remainder on 33th bit
+local function w32_add(a,b) return (a+b) % 4294967296 end
+
+-- adding n 32bit numbers, cutting off the remainder (again)
+local function w32_add_n(a,...)
+  for i=1,select('#',...) do
+    a = (a+select(i,...)) % 4294967296
+  end
+  return a
+end
+-- converting the number to a hexadecimal string
+local function w32_to_hexstring(w) return format("%08x",w) end
+
+local function hex_to_binary(hex)
+  return hex:gsub('..', function(hexval)
+    return string.char(tonumber(hexval, 16))
+  end)
+end
+
+-- building the lookuptables ahead of time (instead of littering the source code
+-- with precalculated values)
+local xor_with_0x5c = {}
+local xor_with_0x36 = {}
+for i=0,0xff do
+  xor_with_0x5c[char(i)] = char(bxor(i,0x5c))
+  xor_with_0x36[char(i)] = char(bxor(i,0x36))
+end
+
+---------------------------------------------------------------------------------
+
+-- calculating the SHA1 for some text
+local function sha1(msg)
+  local H0,H1,H2,H3,H4 = 0x67452301,0xEFCDAB89,0x98BADCFE,0x10325476,0xC3D2E1F0
+  local msg_len_in_bits = #msg * 8
+
+  local first_append = 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 = current_mod>0 and rep(char(0), 64 - current_mod) or ""
+
+  -- now to append the length as a 64-bit number.
+  local B1, R1 = modf(msg_len_in_bits  / 0x01000000)
+  local B2, R2 = modf( 0x01000000 * R1 / 0x00010000)
+  local B3, R3 = modf( 0x00010000 * R2 / 0x00000100)
+  local B4    = 0x00000100 * R3
+
+  local L64 = char( 0) .. char( 0) .. char( 0) .. char( 0) -- high 32 bits
+        .. char(B1) .. char(B2) .. char(B3) .. char(B4) --  low 32 bits
+
+  msg = msg .. first_append .. second_append .. L64
+
+  assert(#msg % 64 == 0)
+
+  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 = chunk * 64 + 1,chunk + 1
+
+    for t = 0, 15 do
+      W[t] = bytes_to_w32(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] = w32_rot(1, w32_xor_n(W[t-3], W[t-8], W[t-14], W[t-16]))
+    end
+
+    A,B,C,D,E = H0,H1,H2,H3,H4
+
+    for t = 0, 79 do
+      if t <= 19 then
+        -- (B AND C) OR ((NOT B) AND D)
+        f = w32_or(w32_and(B, C), w32_and(w32_not(B), D))
+        K = 0x5A827999
+      elseif t <= 39 then
+        -- B XOR C XOR D
+        f = w32_xor_n(B, C, D)
+        K = 0x6ED9EBA1
+      elseif t <= 59 then
+        -- (B AND C) OR (B AND D) OR (C AND D
+        f = w32_or3(w32_and(B, C), w32_and(B, D), w32_and(C, D))
+        K = 0x8F1BBCDC
+      else
+        -- B XOR C XOR D
+        f = w32_xor_n(B, C, D)
+        K = 0xCA62C1D6
+      end
+
+      -- TEMP = S5(A) + ft(B,C,D) + E + Wt + Kt;
+      A,B,C,D,E = w32_add_n(w32_rot(5, A), f, E, W[t], K),
+        A, w32_rot(30, B), C, D
+    end
+    -- Let H0 = H0 + A, H1 = H1 + B, H2 = H2 + C, H3 = H3 + D, H4 = H4 + E.
+    H0,H1,H2,H3,H4 = w32_add(H0, A),w32_add(H1, B),w32_add(H2, C),w32_add(H3, D),w32_add(H4, E)
+  end
+  local f = w32_to_hexstring
+  return f(H0) .. f(H1) .. f(H2) .. f(H3) .. f(H4)
+end
+
+local function sha1_binary(msg)
+  return hex_to_binary(sha1(msg))
+end
+
+local 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 > BLOCK_SIZE then
+    key = sha1_binary(key)
+  end
+
+  local key_xord_with_0x36 = key:gsub('.', xor_with_0x36) .. string.rep(string.char(0x36), BLOCK_SIZE - #key)
+  local key_xord_with_0x5c = key:gsub('.', xor_with_0x5c) .. string.rep(string.char(0x5c), BLOCK_SIZE - #key)
+
+  return sha1(key_xord_with_0x5c .. sha1_binary(key_xord_with_0x36 .. text))
+end
+
+local function hmac_sha1_binary(key, text)
+  return hex_to_binary(hmac_sha1(key, text))
+end
+
+return setmetatable({
+  sha1 = sha1,
+  binary = sha1_binary,
+  hmac = hmac_sha1,
+  hmac_binary = hmac_sha1_binary
+}, {
+  __call = function(_,msg) return sha1(msg) end
+})