From 2394483dc9c1fab2b554d82b84283f18bf8761dd Mon Sep 17 00:00:00 2001
From: crabman77 <crabman77.github@gmail.com>
Date: Sun, 14 Aug 2016 01:53:19 +0200
Subject: [PATCH] update md5.lua (md5sum bug, wrong/no md5 with big data)-->
 fix news don't show when updated

---
 mods/news/md5.lua | 67 ++++++++++++++++++++++++++++-------------------
 1 file changed, 40 insertions(+), 27 deletions(-)

diff --git a/mods/news/md5.lua b/mods/news/md5.lua
index 4a9e7214..5e73ba6b 100644
--- a/mods/news/md5.lua
+++ b/mods/news/md5.lua
@@ -1,5 +1,5 @@
 local md5 = {
-  _VERSION     = "md5.lua 1.0.2",
+  _VERSION     = "md5.lua 1.1.0",
   _DESCRIPTION = "MD5 computation in Lua (5.1-3, LuaJIT)",
   _URL         = "https://github.com/kikito/md5.lua",
   _LICENSE     = [[
@@ -232,15 +232,6 @@ end
 
 local swap = function (w) return str2bei(lei2str(w)) end
 
-local function hex2binaryaux(hexval)
-  return char(tonumber(hexval, 16))
-end
-
-local function hex2binary(hex)
-  local result, _ = hex:gsub('..', hex2binaryaux)
-  return result
-end
-
 -- An MD5 mplementation in Lua, requires bitlib (hacked to use LuaBit from above, ugh)
 -- 10/02/2001 jcw@equi4.com
 
@@ -268,8 +259,8 @@ 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,0xFFFFFFFF)
+local z=function (ff,a,b,c,d,x,s,ac)
+  a=bit_and(a+ff(b,c,d)+x+ac,0xFFFFFFFF)
   -- be *very* careful that left shift does not cause rounding!
   return bit_or(bit_lshift(bit_and(a,bit_rshift(0xFFFFFFFF,s)),s),bit_rshift(a,32-s))+b
 end
@@ -346,38 +337,60 @@ local function transform(A,B,C,D,X)
   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
+  return bit_and(A+a,0xFFFFFFFF),bit_and(B+b,0xFFFFFFFF),
+         bit_and(C+c,0xFFFFFFFF),bit_and(D+d,0xFFFFFFFF)
 end
 
 ----------------------------------------------------------------
 
-function md5.sumhexa(s)
-  local msgLen = #s
+local function md5_update(self, s)
+  self.pos = self.pos + #s
+  s = self.buf .. s
+  for ii = 1, #s - 63, 64 do
+    local X = cut_le_str(sub(s,ii,ii+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!
+    self.a,self.b,self.c,self.d = transform(self.a,self.b,self.c,self.d,X)
+  end
+  self.buf = sub(s, math.floor(#s/64)*64 + 1, #s)
+  return self
+end
+
+local function md5_finish(self)
+  local msgLen = self.pos
   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) .. lei2str(8*msgLen) .. lei2str(0)
+  local s = char(128) .. rep(char(0),padLen-1) .. lei2str(bit_and(8*msgLen, 0xFFFFFFFF)) .. lei2str(math.floor(msgLen/0x20000000))
+  md5_update(self, s)
 
-  assert(#s % 64 == 0)
+  assert(self.pos % 64 == 0)
+  return lei2str(self.a) .. lei2str(self.b) .. lei2str(self.c) .. lei2str(self.d)
+end
 
-  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
+function md5.new()
+  return { a = CONSTS[65], b = CONSTS[66], c = CONSTS[67], d = CONSTS[68],
+           pos = 0,
+           buf = '',
+           update = md5_update,
+           finish = md5_finish }
+end
 
-  return format("%08x%08x%08x%08x",swap(a),swap(b),swap(c),swap(d))
+function md5.tohex(s)
+  return format("%08x%08x%08x%08x", str2bei(sub(s, 1, 4)), str2bei(sub(s, 5, 8)), str2bei(sub(s, 9, 12)), str2bei(sub(s, 13, 16)))
 end
 
 function md5.sum(s)
-  return hex2binary(md5.sumhexa(s))
+  return md5.new():update(s):finish()
+end
+
+function md5.sumhexa(s)
+  return md5.tohex(md5.sum(s))
 end
 
 return md5