Squash MD5SUM.LUA to save disk space.

Author: Lethja

demo/xtra/MD5SUM.LUA

@@ -1,102 +1,35 @@
 #!/usr/bin/env lua
 
---- Read file hash
---- @param file file The file to read (to end)
---- @return string MD5 checksum
+---Get file hash
+---@param file file The file to read
+---@return string MD5 checksum
 function md5_file(file)
-	local function Md5Transform(chunk, A, B, C, D)
-		local F = function(x, y, z) return (x & y) | (~x & z) end
-		local G = function(x, y, z) return (x & z) | (y & ~z) end
-		local H = function(x, y, z) return x ~ y ~ z end
-		local I = function(x, y, z) return y ~ (x | ~z) end
-		local function LS(x, n) return ((x << n) | (x >> (32 - n))) & 0xFFFFFFFF end
-		local wo, sh = {}, {{ 7, 12, 17, 22 }, { 5,  9, 14, 20 }, { 4, 11, 16, 23 }, { 6, 10, 15, 21 }}
-		for i = 0, 15 do
-			local o = i * 4 + 1
-			wo[i + 1] =
-			string.byte(chunk, o) |
-			(string.byte(chunk, o + 1) << 8) |
-			(string.byte(chunk, o + 2) << 16) |
-			(string.byte(chunk, o + 3) << 24)
-		end
-		local a, b, c, d = A, B, C, D
-		for i = 1, 64 do
-			local f, g
-			local r = math.floor((i - 1) / 16) + 1
-			local s = sh[r][(i - 1) % 4 + 1]
-			if r == 1 then
-				f = F(b, c, d)
-				g = (i - 1) % 16
-			elseif r == 2 then
-				f = G(b, c, d)
-				g = (5 * (i - 1) + 1) % 16
-			elseif r == 3 then
-				f = H(b, c, d)
-				g = (3 * (i - 1) + 5) % 16
-			elseif r == 4 then
-				f = I(b, c, d)
-				g = (7 * (i - 1)) % 16
-			end
-			local t = d
-			d = c
-			c = b
-			b = (b + LS((a + f + wo[g + 1] + SINE[i]) & 0xFFFFFFFF, s)) & 0xFFFFFFFF
-			a = t
-		end
-		A = (A + a) & 0xFFFFFFFF
-		B = (B + b) & 0xFFFFFFFF
-		C = (C + c) & 0xFFFFFFFF
-		D = (D + d) & 0xFFFFFFFF
-		return A, B, C, D
-	end
-	local function Md5Pad(messageLength)
-		local ml = messageLength * 8
-		local p = "\128"
-		local pl = (56 - (messageLength % 64))
-		if pl <= 0 then pl = pl + 64 end
-		p = p .. string.rep("\0", pl - 1)
-		for i = 0, 7 do p = p .. string.char((ml >> (8 * i)) & 0xFF) end
-		return p
-	end
-    local A, B, C, D, l = 0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0
+	local MAX=0xFFFFFFFF
+	local function T(ch,A,B,C,D)
+		local F,G,H,I,LS=function(x,y,z)return(x&y)|(~x&z)end,function(x,y,z)return(x&z)|(y&~z)end,function(x,y,z)return x~y~z end,function(x,y,z)return y~(x|~z)end,function(x,n)return((x<<n)|(x>>(32-n)))&MAX end
+		local wo,sh,a,b,c,d={},{{7,12,17,22},{5,9,14,20},{4,11,16,23},{6,10,15,21}},A,B,C,D
+		for i=0,15 do local o=i*4+1 wo[i+1]=string.byte(ch,o)|(string.byte(ch,o+1)<<8)|(string.byte(ch,o+2)<<16)|(string.byte(ch,o+3)<<24)end
+		for i=1,64 do local r,f,g,t=math.floor((i-1)/16)+1 local s=sh[r][(i-1)%4+1]
+			if r==1 then f=F(b,c,d)g=(i-1)%16 elseif r==2 then f=G(b,c,d)g=(5*(i-1)+1)%16 elseif r==3 then f=H(b,c,d)g=(3*(i-1)+5)%16 elseif r==4 then f=I(b,c,d)g=(7*(i-1))%16 end
+			t=d d=c c=b b=(b+LS((a+f+wo[g+1]+SINE[i])&MAX,s))&MAX a=t end
 
-    while 1 do
-        local c = file:read(64)
-        if not c then break end
-        l = l + #c
-        if #c < 64 then c = c .. Md5Pad(l) end
-        A, B, C, D = Md5Transform(c, A, B, C, D)
-        if #c > 64 then break end
-    end
-    local function to_hex(x)
-        return string.format("%02x%02x%02x%02x",
-				x & 0xFF, (x >> 8) & 0xFF, (x >> 16) & 0xFF, (x >> 24) & 0xFF)
-    end
-    return to_hex(A) .. to_hex(B) .. to_hex(C) .. to_hex(D)
-end
+		A=(A+a)&MAX B=(B+b)&MAX C=(C+c)&MAX D=(D+d)&MAX return A,B,C,D end
 
-local function init()
-	SINE = {}
-	for i = 1, 64 do SINE[i] = math.floor(2 ^ 32 * math.abs(math.sin(i))) end
-end
+	local function P(msgLen)
+		local ml,p,pl=msgLen*8,"\128",(56-(msgLen%64))
+		if pl<=0 then pl=pl+64 end p=p..string.rep("\0",pl-1)
+		for i=0,7 do p=p..string.char((ml>>(8*i))&0xFF)end return p end
 
-if LIB then init() return end
-if #arg < 1 then
-    print((arg[-1] or "?") .. " " .. (arg[0] or "?") .. " [FILE]...")
-    os.exit(1)
-else
-	init()
-    for i = 1, #arg do
-        local f, e = io.open(arg[i], "rb")
-        if f then
-            local sum = md5_file(f) f:close()
-            if sum then
-                print(sum .. "  " .. arg[i])
-            else
-                print(arg[i] .. ": " .. "Unknown error") os.exit(-1)
-            end
-        else
-            print(arg[i] .. ": " .. e) os.exit(1)
-        end
-    end
+    local A,B,C,D,l=0x67452301,0xefcdab89,0x98badcfe,0x10325476,0
+    while 1 do local c=file:read(64) if not c then break end l=l+#c if #c<64 then c=c..P(l)end A,B,C,D=T(c,A,B,C,D) if #c>64 then break end end
+    local function hex(x)return string.format("%02x%02x%02x%02x",x&0xFF,(x>>8)&0xFF,(x>>16)&0xFF,(x>>24)&0xFF)end
+    return hex(A)..hex(B)..hex(C)..hex(D)
 end
+
+local function init()SINE={}for i=1,64 do SINE[i]=math.floor(2^32*math.abs(math.sin(i)))end end
+
+if LIB then init()return end
+if #arg<1 then print((arg[-1] or "?").." "..(arg[0] or "?").." [FILE]...")os.exit(1)
+else init()for i=1,#arg do local f,e=io.open(arg[i],"rb")
+	if f then local sum=md5_file(f)f:close()if sum then print(sum.."  "..arg[i])else print(arg[i]..": ".."Unknown error")os.exit(-1)end
+	else print(e)os.exit(1)end end end