local component=require("component")
local M={}
local k={
0x428a2f98,0x71374491,0xb5c0fbcf,0xe9b5dba5,0x3956c25b,0x59f111f1,0x923f82a4,0xab1c5ed5,
0xd807aa98,0x12835b01,0x243185be,0x550c7dc3,0x72be5d74,0x80deb1fe,0x9bdc06a7,0xc19bf174,
0xe49b69c1,0xefbe4786,0x0fc19dc6,0x240ca1cc,0x2de92c6f,0x4a7484aa,0x5cb0a9dc,0x76f988da,
0x983e5152,0xa831c66d,0xb00327c8,0xbf597fc7,0xc6e00bf3,0xd5a79147,0x06ca6351,0x14292967,
0x27b70a85,0x2e1b2138,0x4d2c6dfc,0x53380d13,0x650a7354,0x766a0abb,0x81c2c92e,0x92722c85,
0xa2bfe8a1,0xa81a664b,0xc24b8b70,0xc76c51a3,0xd192e819,0xd6990624,0xf40e3585,0x106aa070,
0x19a4c116,0x1e376c08,0x2748774c,0x34b0bcb5,0x391c0cb3,0x4ed8aa4a,0x5b9cca4f,0x682e6ff3,
0x748f82ee,0x78a5636f,0x84c87814,0x8cc70208,0x90befffa,0xa4506ceb,0xbef9a3f7,0xc67178f2}
local M32=0xFFFFFFFF
local function rotr(x,n)return((x>>n)|(x<<(32-n)))&M32 end

local function lua256(msg)
local len=#msg
msg=msg.."\128"..string.rep("\0",(55-len)%64)..string.pack(">I8",len*8)
local h={0x6a09e667,0xbb67ae85,0x3c6ef372,0xa54ff53a,0x510e527f,0x9b05688c,0x1f83d9ab,0x5be0cd19}
local w={}
for chunk=1,#msg,64 do
for i=0,15 do w[i]=string.unpack(">I4",msg,chunk+i*4)end
for i=16,63 do
local a,b=w[i-15],w[i-2]
local s0=rotr(a,7)~rotr(a,18)~(a>>3)
local s1=rotr(b,17)~rotr(b,19)~(b>>10)
w[i]=(w[i-16]+s0+w[i-7]+s1)&M32
end
local a,b,c,d,e,f,g,hh=h[1],h[2],h[3],h[4],h[5],h[6],h[7],h[8]
for i=0,63 do
local S1=rotr(e,6)~rotr(e,11)~rotr(e,25)
local ch=(e&f)~(~e&g)
local t1=(hh+S1+ch+k[i+1]+w[i])&M32
local S0=rotr(a,2)~rotr(a,13)~rotr(a,22)
local maj=(a&b)~(a&c)~(b&c)
local t2=(S0+maj)&M32
hh,g,f,e,d,c,b,a=g,f,e,(d+t1)&M32,c,b,a,(t1+t2)&M32
end
h[1],h[2],h[3],h[4]=(h[1]+a)&M32,(h[2]+b)&M32,(h[3]+c)&M32,(h[4]+d)&M32
h[5],h[6],h[7],h[8]=(h[5]+e)&M32,(h[6]+f)&M32,(h[7]+g)&M32,(h[8]+hh)&M32
end
return string.format(string.rep("%08x",8),table.unpack(h))
end

function M.hex(s)
if component.isAvailable("data")and component.data.sha256 then
return(component.data.sha256(s):gsub(".",function(c)return string.format("%02x",c:byte())end))
end
return lua256(s)
end


function M.make(pw)
local salt=string.format("%08x",math.random(0,0x7FFFFFFF))
return"sha256$"..salt.."$"..M.hex(salt..pw)
end
function M.check(stored,pw)
if type(stored)~="string"then return false end
local salt,hash=stored:match("^sha256%$(%x+)%$(%x+)$")
if not salt then return false end
return M.hex(salt..pw)==hash
end
M.lua256=lua256
return M