From 8bd617223418b82eea4aacac20b8730ae290d9ca Mon Sep 17 00:00:00 2001 From: localhost_frssoft Date: Mon, 2 Oct 2023 11:23:32 +0300 Subject: [PATCH] migrate to native minetest bitwise operations (except basexx) Thanks https://forum.minetest.net/viewtopic.php?p=429240#p429240 --- functions.lua | 81 ++++++++++----------------------------------------- 1 file changed, 15 insertions(+), 66 deletions(-) diff --git a/functions.lua b/functions.lua index d72b9ed..7572dc5 100644 --- a/functions.lua +++ b/functions.lua @@ -1,65 +1,14 @@ --- https://stackoverflow.com/a/25594410 -local function bitxor(a,b) - local p,c=1,0 - while a>0 and b>0 do - local ra,rb=a%2,b%2 - if ra~=rb then c=c+p end - a,b,p=(a-ra)/2,(b-rb)/2,p*2 - end - if a0 do - local ra=a%2 - if ra>0 then c=c+p end - a,p=(a-ra)/2,p*2 - end - return c -end - -local function bitor(a,b) - local p,c=1,0 - while a+b>0 do - local ra,rb=a%2,b%2 - if ra+rb>0 then c=c+p end - a,b,p=(a-ra)/2,(b-rb)/2,p*2 - end - return c -end - --- https://stackoverflow.com/a/32387452 -local function bitand(a, b) - local result = 0 - local bitval = 1 - while a > 0 and b > 0 do - if a % 2 == 1 and b % 2 == 1 then -- test the rightmost bits - result = result + bitval -- set the current bit - end - bitval = bitval * 2 -- shift left - a = math.floor(a/2) -- shift right - b = math.floor(b/2) - end - return result -end - --- https://gist.github.com/mebens/938502 -local function rshift(x, by) - return math.floor(x / 2 ^ by) -end - -local function lshift(x, by) - return x * 2 ^ by -end - -- big-endian uint64 of a number function fediauth.write_uint64_be(v) - local b1 = bitand( rshift(v, 56), 0xFF ) - local b2 = bitand( rshift(v, 48), 0xFF ) - local b3 = bitand( rshift(v, 40), 0xFF ) - local b4 = bitand( rshift(v, 32), 0xFF ) - local b5 = bitand( rshift(v, 24), 0xFF ) - local b6 = bitand( rshift(v, 16), 0xFF ) - local b7 = bitand( rshift(v, 8), 0xFF ) - local b8 = bitand( rshift(v, 0), 0xFF ) + local b1 = bit.band( bit.rshift(v, 56), 0xFF ) + local b2 = bit.band( bit.rshift(v, 48), 0xFF ) + local b3 = bit.band( bit.rshift(v, 40), 0xFF ) + local b4 = bit.band( bit.rshift(v, 32), 0xFF ) + local b5 = bit.band( bit.rshift(v, 24), 0xFF ) + local b6 = bit.band( bit.rshift(v, 16), 0xFF ) + local b7 = bit.band( bit.rshift(v, 8), 0xFF ) + local b8 = bit.band( bit.rshift(v, 0), 0xFF ) return string.char(b1, b2, b3, b4, b5, b6, b7, b8) end @@ -76,13 +25,13 @@ end function fediauth.hmac(key, message) local i_key_pad = "" for i=1,64 do - i_key_pad = i_key_pad .. string.char(bitxor(string.byte(key, i) or 0x00, string.byte(i_pad, i))) + i_key_pad = i_key_pad .. string.char(bit.bxor(string.byte(key, i) or 0x00, string.byte(i_pad, i))) end assert(#i_key_pad == 64) local o_key_pad = "" for i=1,64 do - o_key_pad = o_key_pad .. string.char(bitxor(string.byte(key, i) or 0x00, string.byte(o_pad, i))) + o_key_pad = o_key_pad .. string.char(bit.bxor(string.byte(key, i) or 0x00, string.byte(o_pad, i))) end assert(#o_key_pad == 64) @@ -129,12 +78,12 @@ function fediauth.generate_tfediauth(secret_b32, unix_time) local hmac = fediauth.hmac(key, counter) -- https://www.rfc-editor.org/rfc/rfc4226#section-5.4 - local offset = bitand(string.byte(hmac, #hmac), 0xF) + local offset = bit.band(string.byte(hmac, #hmac), 0xF) local value = 0 - value = bitor(value, string.byte(hmac, offset+4)) - value = bitor(value, lshift(string.byte(hmac, offset+3), 8)) - value = bitor(value, lshift(string.byte(hmac, offset+2), 16)) - value = bitor(value, lshift(bitand(string.byte(hmac, offset+1), 0x7F), 24)) + value = bit.bxor(value, string.byte(hmac, offset+4)) + value = bit.bxor(value, bit.lshift(string.byte(hmac, offset+3), 8)) + value = bit.bxor(value, bit.lshift(string.byte(hmac, offset+2), 16)) + value = bit.bxor(value, bit.lshift(bit.band(string.byte(hmac, offset+1), 0x7F), 24)) local code = value % 10^6 local padded_code = left_pad("" .. code, "0", 6)