MD5 using Gideros BitOp plugin

ianchia

I needed a MD5 hash in a hurry and found a MD5 implementation in the BitOp demos. Just a quick&dirty wrapper into a Gideros class leveraging the Gideros BitOp plugin. I prefer SHA-1 but MD5 was perfectly acceptable in this particular use-case.

--usage: crypto = Crypto.new(); local a = os.timer(); print (crypto:md5("The quick brown fox")); local b = os.timer(); print ("on an iPad2, time taken for MD5 hash: ",b-a); -- -- a2004f37730b9445670a738fa0fc9ee5 -- on an iPad2, time taken for MD5 hash: 0.00027698278427124   -- you can compare the result to various online MD5 generators. -- eg. <a href="http://www.miraclesalad.com/webtools/md5.php" rel="nofollow">http://www.miraclesalad.com/webtools/md5.php</a> -- <a href="http://7thspace.com/webmaster_tools/online_md5_encoder.html" rel="nofollow">http://7thspace.com/webmaster_tools/online_md5_encoder.html</a>   -- the unit tests supplied with the md5 BitOp demo also passed with no issues: assert(md5('') == 'd41d8cd98f00b204e9800998ecf8427e') assert(md5('a') == '0cc175b9c0f1b6a831c399e269772661') assert(md5('abc') == '900150983cd24fb0d6963f7d28e17f72') assert(md5('message digest') == 'f96b697d7cb7938d525a2f31aaf161d0') assert(md5('abcdefghijklmnopqrstuvwxyz') == 'c3fcd3d76192e4007dfb496cca67e13b') assert(md5('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789') == 'd174ab98d277d9f5a5611c2c9f419d9f') assert(md5('12345678901234567890123456789012345678901234567890123456789012345678901234567890') == '57edf4a22be3c955ac49da2e2107b67a')   --/////////////////////////////////////////////////////////////////////////////////////   -- Crypto.lua (also attached)   -- pretty much a cut & paste from the bitop supplied demos from <a href="http://bitop.luajit.org/download.html" rel="nofollow">http://bitop.luajit.org/download.html</a> -- wrapped into a Gideros class Crypto = Core.class()   function Crypto:init()   end   -- md5() -- usage: -- crypto = Crypto.new(); -- print (crypto:md5("The quick brown fox")); -- function Crypto:md5(input_string)   local bit = require("bit") local tobit, tohex, bnot = bit.tobit or bit.cast, bit.tohex, bit.bnot local bor, band, bxor = bit.bor, bit.band, bit.bxor local lshift, rshift, rol, bswap = bit.lshift, bit.rshift, bit.rol, bit.bswap local byte, char, sub, rep = string.byte, string.char, string.sub, string.rep   if not rol then -- Replacement function if rotates are missing. local bor, shl, shr = bit.bor, bit.lshift, bit.rshift function rol(a, b) return bor(shl(a, b), shr(a, 32-b)) end end   if not bswap then -- Replacement function if bswap is missing. local bor, band, shl, shr = bit.bor, bit.band, bit.lshift, bit.rshift function bswap(a) return bor(shr(a, 24), band(shr(a, 8), 0xff00), shl(band(a, 0xff00), 8), shl(a, 24)); end end   if not tohex then -- (Unreliable) replacement function if tohex is missing. function tohex(a) return string.sub(string.format("%08x", a), -8) end end   local function tr_f(a, b, c, d, x, s) return rol(bxor(d, band(b, bxor(c, d))) + a + x, s) + b end   local function tr_g(a, b, c, d, x, s) return rol(bxor(c, band(d, bxor(b, c))) + a + x, s) + b end   local function tr_h(a, b, c, d, x, s) return rol(bxor(b, c, d) + a + x, s) + b end   local function tr_i(a, b, c, d, x, s) return rol(bxor(c, bor(b, bnot(d))) + a + x, s) + b end   local function transform(x, a1, b1, c1, d1) local a, b, c, d = a1, b1, c1, d1   a = tr_f(a, b, c, d, x[ 1] + 0xd76aa478, 7) d = tr_f(d, a, b, c, x[ 2] + 0xe8c7b756, 12) c = tr_f(c, d, a, b, x[ 3] + 0x242070db, 17) b = tr_f(b, c, d, a, x[ 4] + 0xc1bdceee, 22) a = tr_f(a, b, c, d, x[ 5] + 0xf57c0faf, 7) d = tr_f(d, a, b, c, x[ 6] + 0x4787c62a, 12) c = tr_f(c, d, a, b, x[ 7] + 0xa8304613, 17) b = tr_f(b, c, d, a, x[ 8] + 0xfd469501, 22) a = tr_f(a, b, c, d, x[ 9] + 0x698098d8, 7) d = tr_f(d, a, b, c, x[10] + 0x8b44f7af, 12) c = tr_f(c, d, a, b, x[11] + 0xffff5bb1, 17) b = tr_f(b, c, d, a, x[12] + 0x895cd7be, 22) a = tr_f(a, b, c, d, x[13] + 0x6b901122, 7) d = tr_f(d, a, b, c, x[14] + 0xfd987193, 12) c = tr_f(c, d, a, b, x[15] + 0xa679438e, 17) b = tr_f(b, c, d, a, x[16] + 0x49b40821, 22)   a = tr_g(a, b, c, d, x[ 2] + 0xf61e2562, 5) d = tr_g(d, a, b, c, x[ 7] + 0xc040b340, 9) c = tr_g(c, d, a, b, x[12] + 0x265e5a51, 14) b = tr_g(b, c, d, a, x[ 1] + 0xe9b6c7aa, 20) a = tr_g(a, b, c, d, x[ 6] + 0xd62f105d, 5) d = tr_g(d, a, b, c, x[11] + 0x02441453, 9) c = tr_g(c, d, a, b, x[16] + 0xd8a1e681, 14) b = tr_g(b, c, d, a, x[ 5] + 0xe7d3fbc8, 20) a = tr_g(a, b, c, d, x[10] + 0x21e1cde6, 5) d = tr_g(d, a, b, c, x[15] + 0xc33707d6, 9) c = tr_g(c, d, a, b, x[ 4] + 0xf4d50d87, 14) b = tr_g(b, c, d, a, x[ 9] + 0x455a14ed, 20) a = tr_g(a, b, c, d, x[14] + 0xa9e3e905, 5) d = tr_g(d, a, b, c, x[ 3] + 0xfcefa3f8, 9) c = tr_g(c, d, a, b, x[ 8] + 0x676f02d9, 14) b = tr_g(b, c, d, a, x[13] + 0x8d2a4c8a, 20)   a = tr_h(a, b, c, d, x[ 6] + 0xfffa3942, 4) d = tr_h(d, a, b, c, x[ 9] + 0x8771f681, 11) c = tr_h(c, d, a, b, x[12] + 0x6d9d6122, 16) b = tr_h(b, c, d, a, x[15] + 0xfde5380c, 23) a = tr_h(a, b, c, d, x[ 2] + 0xa4beea44, 4) d = tr_h(d, a, b, c, x[ 5] + 0x4bdecfa9, 11) c = tr_h(c, d, a, b, x[ 8] + 0xf6bb4b60, 16) b = tr_h(b, c, d, a, x[11] + 0xbebfbc70, 23) a = tr_h(a, b, c, d, x[14] + 0x289b7ec6, 4) d = tr_h(d, a, b, c, x[ 1] + 0xeaa127fa, 11) c = tr_h(c, d, a, b, x[ 4] + 0xd4ef3085, 16) b = tr_h(b, c, d, a, x[ 7] + 0x04881d05, 23) a = tr_h(a, b, c, d, x[10] + 0xd9d4d039, 4) d = tr_h(d, a, b, c, x[13] + 0xe6db99e5, 11) c = tr_h(c, d, a, b, x[16] + 0x1fa27cf8, 16) b = tr_h(b, c, d, a, x[ 3] + 0xc4ac5665, 23)   a = tr_i(a, b, c, d, x[ 1] + 0xf4292244, 6) d = tr_i(d, a, b, c, x[ 8] + 0x432aff97, 10) c = tr_i(c, d, a, b, x[15] + 0xab9423a7, 15) b = tr_i(b, c, d, a, x[ 6] + 0xfc93a039, 21) a = tr_i(a, b, c, d, x[13] + 0x655b59c3, 6) d = tr_i(d, a, b, c, x[ 4] + 0x8f0ccc92, 10) c = tr_i(c, d, a, b, x[11] + 0xffeff47d, 15) b = tr_i(b, c, d, a, x[ 2] + 0x85845dd1, 21) a = tr_i(a, b, c, d, x[ 9] + 0x6fa87e4f, 6) d = tr_i(d, a, b, c, x[16] + 0xfe2ce6e0, 10) c = tr_i(c, d, a, b, x[ 7] + 0xa3014314, 15) b = tr_i(b, c, d, a, x[14] + 0x4e0811a1, 21) a = tr_i(a, b, c, d, x[ 5] + 0xf7537e82, 6) d = tr_i(d, a, b, c, x[12] + 0xbd3af235, 10) c = tr_i(c, d, a, b, x[ 3] + 0x2ad7d2bb, 15) b = tr_i(b, c, d, a, x[10] + 0xeb86d391, 21)   return tobit(a+a1), tobit(b+b1), tobit(c+c1), tobit(d+d1) end   -- Note: this is copying the original string and NOT particularly fast. -- A library for struct unpacking would make this task much easier. local function md5(msg) local len = #msg msg = msg.."\128"..rep("\0", 63 - band(len + 8, 63)) ..char(band(lshift(len, 3), 255), band(rshift(len, 5), 255), band(rshift(len, 13), 255), band(rshift(len, 21), 255)) .."\0\0\0\0" local a, b, c, d = 0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476 local x, k = {}, 1 for i=1,#msg,4 do local m0, m1, m2, m3 = byte(msg, i, i+3) x[k] = bor(m0, lshift(m1, 8), lshift(m2, 16), lshift(m3, 24)) if k == 16 then a, b, c, d = transform(x, a, b, c, d) k = 1 else k = k + 1 end end return tohex(bswap(a))..tohex(bswap(b))..tohex(bswap(c))..tohex(bswap(d)) end   return md5(input_string);   end

gim

Nice work! LTN12 version is here.

function sink.md5() -- local variables except function md5(msg) in Crypto:md5(input_string) should be here as original posting.   local len = 0 local msg = "" local a, b, c, d = 0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476 local x, k = {}, 1 local closed   return function(chunk, err) local index = 1 if not chunk then if closed then return nil, "closed" end closed = true msg = msg.."\128"..rep("\0", 63 - band(len + 8, 63)) ..char(band(lshift(len, 3), 255), band(rshift(len, 5), 255),band(rshift(len, 13), 255), band(rshift(len, 21), 255)) .."\0\0\0\0" else len = len + #chunk if #msg < 1 then msg = chunk else if #msg + #chunk < 4 then msg = msg..chunk else index = 5 - #msg msg = msg..sub(chunk, 1, 4 - #msg) local m0, m1, m2, m3 = byte(msg, 1, 4) x[k] = bor(m0, lshift(m1, 8), lshift(m2, 16), lshift(m3, 24)) if k == 16 then a, b, c, d = transform(x, a, b, c, d) k = 1 else k = k + 1 end msg = chunk end end end for i=index,#msg-band(#msg-index+1, 3),4 do local m0, m1, m2, m3 = byte(msg, i, i+3) x[k] = bor(m0, lshift(m1, 8), lshift(m2, 16), lshift(m3, 24)) if k == 16 then a, b, c, d = transform(x, a, b, c, d) k = 1 else k = k + 1 end end msg = sub(msg, #msg-band(#msg-index+1, 3)+1) return tohex(bswap(a))..tohex(bswap(b))..tohex(bswap(c))..tohex(bswap(d)) end end

Wrapper function Crypto:md5 would be:

function Crypto:md5(input_string) local source = ltn12.source.string(input_string) local sink = ltn12.sink.md5() local chunk = source() while chunk do sink(chunk) chunk = source() end return sink(nil, "closed") end