initial commit with working implementation, readme and license

2013-08-30 19:12:29 +02:00 · 2013-08-30 19:12:29 +02:00 · dab1b130bd
commit dab1b130bd
4 changed files with 444 additions and 0 deletions
--- a/MIT-LICENSE.txt
+++ b/MIT-LICENSE.txt
@ -0,0 +1,20 @@
+Copyright (c) 2013 Enrique García Cota + Adam Baldwin + hanzao + Equi 4 Software
+
+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.
--- a/README.md
+++ b/README.md
@ -0,0 +1,40 @@
+md5.lua
+========
+
+This pure-Lua module computes md5 in Lua 5.1.
+
+It implements md5.sum and md5.sumhex like the [kernel project md5 package](http://www.keplerproject.org/md5/), but it's done completely in Lua, with no dependencies on other libs or C files.
+
+Usage
+=====
+
+    local md5 = require 'md5'
+
+    local md5_as_hex   = md5.sumhex(message)   -- returns a hex string
+    local md5_as_data  = md5.sum(message)     -- returns raw bytes
+
+Credits
+=======
+
+This is a cleanup of an implementation by Adam Baldwin - https://gist.github.com/evilpacket/3647908
+
+Which in turn was a mix of the bitwise lib, http://luaforge.net/projects/bit/ by hanzhao (`abrash_han - at - hotmail.com`),
+and http://equi4.com/md5/md5calc.lua, by Equi 4 Software.
+
+
+License
+=======
+
+This library, as well as all the previous ones in which is based, is released under the MIT license (See license file for details).
+
+Specs
+=====
+
+The specs for this library are implemented with [busted](http://ovinelabs.com/busted/). In order to run them, install busted and then:
+
+    cd path/to/where/the/spec/folder/is
+    busted
+
+
+
+
--- a/md5.lua
+++ b/md5.lua
@ -0,0 +1,356 @@
+-------------------------------------------------------------------------------
+-- MD5 computation in Lua (5.1)
+-------------------------------------------------------------------------------
+-- bit lib implementions
+
+local floor, abs, max = math.floor, math.abs, math.max
+local char, byte, format, rep, sub =
+  string.char, string.byte, string.format, string.rep, string.sub
+
+local function check_int(n)
+  -- checking not float
+  if(n - floor(n) > 0) then
+    error("trying to use bitwise operation on non-integer!")
+  end
+end
+
+local function tbl_to_number(tbl)
+  local n = #tbl
+
+  local rslt = 0
+  local power = 1
+  for i = 1, n do
+    rslt = rslt + tbl[i]*power
+    power = power*2
+  end
+
+  return rslt
+end
+
+local function expand(tbl_m, tbl_n)
+  local big = {}
+  local small = {}
+  if(#tbl_m > #tbl_n) then
+    big = tbl_m
+    small = tbl_n
+  else
+    big = tbl_n
+    small = tbl_m
+  end
+  -- expand small
+  for i = #small + 1, #big do
+    small[i] = 0
+  end
+
+end
+
+local to_bits -- needs to be declared before bit_not
+
+local function bit_not(n)
+  local tbl = to_bits(n)
+  local size = max(#tbl, 32)
+  for i = 1, size do
+    if(tbl[i] == 1) then
+      tbl[i] = 0
+    else
+      tbl[i] = 1
+    end
+  end
+  return tbl_to_number(tbl)
+end
+
+-- defined as local above
+to_bits = function (n)
+  check_int(n)
+  if(n < 0) then
+    -- negative
+    return to_bits(bit_not(abs(n)) + 1)
+  end
+  -- to bits table
+  local tbl = {}
+  local cnt = 1
+  while (n > 0) do
+    local last = math.mod(n,2)
+    if(last == 1) then
+      tbl[cnt] = 1
+    else
+      tbl[cnt] = 0
+    end
+    n = (n-last)/2
+    cnt = cnt + 1
+  end
+
+  return tbl
+end
+
+local function bit_or(m, n)
+  local tbl_m = to_bits(m)
+  local tbl_n = to_bits(n)
+  expand(tbl_m, tbl_n)
+
+  local tbl = {}
+  local rslt = max(#tbl_m, #tbl_n)
+  for i = 1, rslt do
+    if(tbl_m[i]== 0 and tbl_n[i] == 0) then
+      tbl[i] = 0
+    else
+      tbl[i] = 1
+    end
+  end
+
+  return tbl_to_number(tbl)
+end
+
+local function bit_and(m, n)
+  local tbl_m = to_bits(m)
+  local tbl_n = to_bits(n)
+  expand(tbl_m, tbl_n)
+
+  local tbl = {}
+  local rslt = max(#tbl_m, #tbl_n)
+  for i = 1, rslt do
+    if(tbl_m[i]== 0 or tbl_n[i] == 0) then
+      tbl[i] = 0
+    else
+      tbl[i] = 1
+    end
+  end
+
+  return tbl_to_number(tbl)
+end
+
+local function bit_xor(m, n)
+  local tbl_m = to_bits(m)
+  local tbl_n = to_bits(n)
+  expand(tbl_m, tbl_n)
+
+  local tbl = {}
+  local rslt = max(#tbl_m, #tbl_n)
+  for i = 1, rslt do
+    if(tbl_m[i] ~= tbl_n[i]) then
+      tbl[i] = 1
+    else
+      tbl[i] = 0
+    end
+  end
+
+  return tbl_to_number(tbl)
+end
+
+local function bit_rshift(n, bits)
+  check_int(n)
+
+  local high_bit = 0
+  if(n < 0) then
+    -- negative
+    n = bit_not(abs(n)) + 1
+    high_bit = 2147483648 -- 0x80000000
+  end
+
+  for i=1, bits do
+    n = n/2
+    n = bit_or(floor(n), high_bit)
+  end
+  return floor(n)
+end
+
+local function bit_lshift(n, bits)
+  check_int(n)
+
+  if(n < 0) then
+    -- negative
+    n = bit_not(abs(n)) + 1
+  end
+
+  for i=1, bits do
+    n = n*2
+  end
+  return bit_and(n, 4294967295) -- 0xFFFFFFFF
+end
+
+-- convert little-endian 32-bit int to a 4-char string
+local function lei_2_str(i)
+  local f=function (s) return char( bit_and( bit_rshift(i, s), 255)) end
+  return f(0)..f(8)..f(16)..f(24)
+end
+
+-- convert raw string to big-endian int
+local function str_2_bei(s)
+  local v=0
+  for i=1, #s do
+    v = v * 256 + byte(s, i)
+  end
+  return v
+end
+
+-- convert raw string to little-endian int
+local function str_2_lei(s)
+  local v=0
+  for i = #s,1,-1 do
+    v = v*256 + byte(s, i)
+  end
+  return v
+end
+
+-- cut up a string in little-endian ints of given size
+local function cut_le_str(s,...)
+  local o, r = 1, {}
+  local args = {...}
+  for i=1, #args do
+    table.insert(r, str_2_lei(sub(s, o, o + args[i] - 1)))
+    o = o + args[i]
+  end
+  return r
+end
+
+local swap = function (w) return str_2_bei(lei_2_str(w)) end
+
+local function hex_to_binary(hex)
+  local result, _ = hex:gsub('..', function(hexval)
+    return string.char(tonumber(hexval, 16))
+  end)
+  return result
+end
+
+-- An MD5 mplementation in Lua, requires bitlib (hacked to use LuaBit from above, ugh)
+-- 10/02/2001 jcw@equi4.com
+
+local FF     = 0xffffffff
+local CONSTS = {
+  0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
+  0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
+  0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
+  0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
+  0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
+  0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
+  0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
+  0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
+  0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
+  0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
+  0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05,
+  0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
+  0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
+  0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
+  0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
+  0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391,
+  0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476
+}
+
+local f=function (x,y,z) return bit_or(bit_and(x,y),bit_and(-x-1,z)) end
+local g=function (x,y,z) return bit_or(bit_and(x,z),bit_and(y,-z-1)) end
+local h=function (x,y,z) return bit_xor(x,bit_xor(y,z)) end
+local i=function (x,y,z) return bit_xor(y,bit_or(x,-z-1)) end
+local z=function (f,a,b,c,d,x,s,ac)
+  a=bit_and(a+f(b,c,d)+x+ac,FF)
+  -- be *very* careful that left shift does not cause rounding!
+  return bit_or(bit_lshift(bit_and(a,bit_rshift(FF,s)),s),bit_rshift(a,32-s))+b
+end
+
+local function transform(A,B,C,D,X)
+  local a,b,c,d=A,B,C,D
+  local t=CONSTS
+
+  a=z(f,a,b,c,d,X[ 0], 7,t[ 1])
+  d=z(f,d,a,b,c,X[ 1],12,t[ 2])
+  c=z(f,c,d,a,b,X[ 2],17,t[ 3])
+  b=z(f,b,c,d,a,X[ 3],22,t[ 4])
+  a=z(f,a,b,c,d,X[ 4], 7,t[ 5])
+  d=z(f,d,a,b,c,X[ 5],12,t[ 6])
+  c=z(f,c,d,a,b,X[ 6],17,t[ 7])
+  b=z(f,b,c,d,a,X[ 7],22,t[ 8])
+  a=z(f,a,b,c,d,X[ 8], 7,t[ 9])
+  d=z(f,d,a,b,c,X[ 9],12,t[10])
+  c=z(f,c,d,a,b,X[10],17,t[11])
+  b=z(f,b,c,d,a,X[11],22,t[12])
+  a=z(f,a,b,c,d,X[12], 7,t[13])
+  d=z(f,d,a,b,c,X[13],12,t[14])
+  c=z(f,c,d,a,b,X[14],17,t[15])
+  b=z(f,b,c,d,a,X[15],22,t[16])
+
+  a=z(g,a,b,c,d,X[ 1], 5,t[17])
+  d=z(g,d,a,b,c,X[ 6], 9,t[18])
+  c=z(g,c,d,a,b,X[11],14,t[19])
+  b=z(g,b,c,d,a,X[ 0],20,t[20])
+  a=z(g,a,b,c,d,X[ 5], 5,t[21])
+  d=z(g,d,a,b,c,X[10], 9,t[22])
+  c=z(g,c,d,a,b,X[15],14,t[23])
+  b=z(g,b,c,d,a,X[ 4],20,t[24])
+  a=z(g,a,b,c,d,X[ 9], 5,t[25])
+  d=z(g,d,a,b,c,X[14], 9,t[26])
+  c=z(g,c,d,a,b,X[ 3],14,t[27])
+  b=z(g,b,c,d,a,X[ 8],20,t[28])
+  a=z(g,a,b,c,d,X[13], 5,t[29])
+  d=z(g,d,a,b,c,X[ 2], 9,t[30])
+  c=z(g,c,d,a,b,X[ 7],14,t[31])
+  b=z(g,b,c,d,a,X[12],20,t[32])
+
+  a=z(h,a,b,c,d,X[ 5], 4,t[33])
+  d=z(h,d,a,b,c,X[ 8],11,t[34])
+  c=z(h,c,d,a,b,X[11],16,t[35])
+  b=z(h,b,c,d,a,X[14],23,t[36])
+  a=z(h,a,b,c,d,X[ 1], 4,t[37])
+  d=z(h,d,a,b,c,X[ 4],11,t[38])
+  c=z(h,c,d,a,b,X[ 7],16,t[39])
+  b=z(h,b,c,d,a,X[10],23,t[40])
+  a=z(h,a,b,c,d,X[13], 4,t[41])
+  d=z(h,d,a,b,c,X[ 0],11,t[42])
+  c=z(h,c,d,a,b,X[ 3],16,t[43])
+  b=z(h,b,c,d,a,X[ 6],23,t[44])
+  a=z(h,a,b,c,d,X[ 9], 4,t[45])
+  d=z(h,d,a,b,c,X[12],11,t[46])
+  c=z(h,c,d,a,b,X[15],16,t[47])
+  b=z(h,b,c,d,a,X[ 2],23,t[48])
+
+  a=z(i,a,b,c,d,X[ 0], 6,t[49])
+  d=z(i,d,a,b,c,X[ 7],10,t[50])
+  c=z(i,c,d,a,b,X[14],15,t[51])
+  b=z(i,b,c,d,a,X[ 5],21,t[52])
+  a=z(i,a,b,c,d,X[12], 6,t[53])
+  d=z(i,d,a,b,c,X[ 3],10,t[54])
+  c=z(i,c,d,a,b,X[10],15,t[55])
+  b=z(i,b,c,d,a,X[ 1],21,t[56])
+  a=z(i,a,b,c,d,X[ 8], 6,t[57])
+  d=z(i,d,a,b,c,X[15],10,t[58])
+  c=z(i,c,d,a,b,X[ 6],15,t[59])
+  b=z(i,b,c,d,a,X[13],21,t[60])
+  a=z(i,a,b,c,d,X[ 4], 6,t[61])
+  d=z(i,d,a,b,c,X[11],10,t[62])
+  c=z(i,c,d,a,b,X[ 2],15,t[63])
+  b=z(i,b,c,d,a,X[ 9],21,t[64])
+
+  return A+a,B+b,C+c,D+d
+end
+
+local md5 = {}
+
+function md5.sumhexa(s)
+  local msgLen = #s
+  local padLen = 56 - msgLen % 64
+
+  if msgLen % 64 > 56 then padLen = padLen + 64 end
+
+  if padLen == 0 then padLen = 64 end
+
+  s = s .. char(128) .. rep(char(0),padLen-1) ..
+      lei_2_str(8*msgLen) .. lei_2_str(0)
+
+  assert(#s % 64 == 0)
+
+  local t = CONSTS
+  local a,b,c,d = t[65],t[66],t[67],t[68]
+
+  for i=1,#s,64 do
+    local X = cut_le_str(sub(s,i,i+63),4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4)
+    assert(#X == 16)
+    X[0] = table.remove(X,1) -- zero based!
+    a,b,c,d = transform(a,b,c,d,X)
+  end
+
+  return format("%08x%08x%08x%08x",swap(a),swap(b),swap(c),swap(d))
+end
+
+function md5.sum(s)
+  return hex_to_binary(md5.sumhexa(s))
+end
+
+return md5
--- a/spec/md5_spec.lua
+++ b/spec/md5_spec.lua
@ -0,0 +1,28 @@
+local md5 = require('md5')
+
+local function hex2bin(hex)
+  local result, _ = hex:gsub('..', function(hexval)
+    return string.char(tonumber(hexval, 16))
+  end)
+  return result
+end
+
+describe('md5', function()
+  describe('md5.sumhexa', function()
+    it('works', function()
+      assert.equal(md5.sumhexa("asdf"), '912ec803b2ce49e4a541068d495ab570')
+      assert.equal(md5.sumhexa('The quick brown fox jumps over the lazy dog'), '9e107d9d372bb6826bd81d3542a419d6')
+      assert.equal(md5.sumhexa('The quick brown fox jumps over the lazy dog.'), 'e4d909c290d0fb1ca068ffaddf22cbd0')
+      assert.equal(md5.sumhexa(''), 'd41d8cd98f00b204e9800998ecf8427e')
+    end)
+  end)
+
+  describe('md5.sum', function()
+    it('works', function()
+      assert.equal(md5.sum("asdf"), hex2bin '912ec803b2ce49e4a541068d495ab570')
+      assert.equal(md5.sum('The quick brown fox jumps over the lazy dog'), hex2bin'9e107d9d372bb6826bd81d3542a419d6')
+      assert.equal(md5.sum('The quick brown fox jumps over the lazy dog.'), hex2bin'e4d909c290d0fb1ca068ffaddf22cbd0')
+      assert.equal(md5.sum(''), hex2bin'd41d8cd98f00b204e9800998ecf8427e')
+    end)
+  end)
+end)