migrate to native minetest bitwise operations (except basexx)

Thanks https://forum.minetest.net/viewtopic.php?p=429240#p429240
This commit is contained in:
localhost_frssoft 2023-10-02 11:23:32 +03:00
parent 09b949c755
commit 8bd6172234
1 changed files with 15 additions and 66 deletions

View File

@ -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 a<b then a=b end
while a>0 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)