fade_music: Import SHA256 hashing for authentication

fade_music.lua

@@ -4,9 +4,10 @@
 -- the next time you change scenes.
 
 HOST = "192.168.0.19"
-PORT = 4444
+PORT = 4455
 PASSWORD = "correct-horse-battery-staple"
 sock = nil
+buf = ""
 
 function descriptor()
 	return { 
@@ -17,22 +18,241 @@ function descriptor()
 	}
 end
 
+-- https://github.com/MaHuJa/CC-scripts/blob/master/sha256.lua
+-- Tweaked to remove the need for setmetatable() which probably comes at a steep performance
+-- penalty (no memoization), but this is only for initial authentication handshake
+
+-- From http://pastebin.com/gsFrNjbt linked from http://www.computercraft.info/forums2/index.php?/topic/8169-sha-256-in-pure-lua/
+
+--  Adaptation of the Secure Hashing Algorithm (SHA-244/256)
+--  Found Here: http://lua-users.org/wiki/SecureHashAlgorithm
+--  Using an adapted version of the bit library
+--  Found Here: https://bitbucket.org/Boolsheet/bslf/src/1ee664885805/bit.lua
+
+local MOD = 2^32
+local MODM = MOD-1
+local function make_bitop_uncached(t, m)
+	local function bitop(a, b)
+		local res,p = 0,1
+		while a ~= 0 and b ~= 0 do
+			local am, bm = a % m, b % m
+			res = res + t[am][bm] * p
+			a = (a - am) / m
+			b = (b - bm) / m
+			p = p*m
+		end
+		res = res + (a + b) * p
+		return res
+	end
+	return bitop
+end
+
+local bxor1 = make_bitop_uncached({[0] = {[0] = 0,[1] = 1}, [1] = {[0] = 1, [1] = 0}}, 2)
+
+local function bxor(a, b, c, ...)
+	local z = nil
+	if b then
+		a = a % MOD
+		b = b % MOD
+		z = bxor1(a, b)
+		if c then z = bxor(z, c, ...) end
+		return z
+	elseif a then return a % MOD
+	else return 0 end
+end
+
+local function band(a, b, c, ...)
+	local z
+	if b then
+		a = a % MOD
+		b = b % MOD
+		z = ((a + b) - bxor1(a,b)) / 2
+		if c then z = bit32_band(z, c, ...) end
+		return z
+	elseif a then return a % MOD
+	else return MODM end
+end
+
+local function bnot(x) return (-1 - x) % MOD end
+
+local function rshift1(a, disp)
+	if disp < 0 then return lshift(a,-disp) end
+	return math.floor(a % 2 ^ 32 / 2 ^ disp)
+end
+
+local function rshift(x, disp)
+	if disp > 31 or disp < -31 then return 0 end
+	return rshift1(x % MOD, disp)
+end
+
+local function lshift(a, disp)
+	if disp < 0 then return rshift(a,-disp) end 
+	return (a * 2 ^ disp) % 2 ^ 32
+end
+
+local function rrotate(x, disp)
+    x = x % MOD
+    disp = disp % 32
+    local low = band(x, 2 ^ disp - 1)
+    return rshift(x, disp) + lshift(low, 32 - disp)
+end
+
+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 function str2hexa(s)
+	return (string.gsub(s, ".", function(c) return string.format("%02x", string.byte(c)) end))
+end
+
+local function num2s(l, n)
+	local s = ""
+	for i = 1, n do
+		local rem = l % 256
+		s = string.char(rem) .. s
+		l = (l - rem) / 256
+	end
+	return s
+end
+
+local function s232num(s, i)
+	local n = 0
+	for i = i, i + 3 do n = n*256 + string.byte(s, i) end
+	return n
+end
+
+local function preproc(msg, len)
+	local extra = 64 - ((len + 9) % 64)
+	len = num2s(8 * len, 8)
+	msg = msg .. "\128" .. string.rep("\0", extra) .. len
+	assert(#msg % 64 == 0)
+	return msg
+end
+
+local function initH256(H)
+	H[1] = 0x6a09e667
+	H[2] = 0xbb67ae85
+	H[3] = 0x3c6ef372
+	H[4] = 0xa54ff53a
+	H[5] = 0x510e527f
+	H[6] = 0x9b05688c
+	H[7] = 0x1f83d9ab
+	H[8] = 0x5be0cd19
+	return H
+end
+
+local function digestblock(msg, i, H)
+	local w = {}
+	for j = 1, 16 do w[j] = s232num(msg, i + (j - 1)*4) end
+	for j = 17, 64 do
+		local v = w[j - 15]
+		local s0 = bxor(rrotate(v, 7), rrotate(v, 18), rshift(v, 3))
+		v = w[j - 2]
+		w[j] = w[j - 16] + s0 + w[j - 7] + bxor(rrotate(v, 17), rrotate(v, 19), rshift(v, 10))
+	end
+
+	local a, b, c, d, e, f, g, h = H[1], H[2], H[3], H[4], H[5], H[6], H[7], H[8]
+	for i = 1, 64 do
+		local s0 = bxor(rrotate(a, 2), rrotate(a, 13), rrotate(a, 22))
+		local maj = bxor(band(a, b), band(a, c), band(b, c))
+		local t2 = s0 + maj
+		local s1 = bxor(rrotate(e, 6), rrotate(e, 11), rrotate(e, 25))
+		local ch = bxor (band(e, f), band(bnot(e), g))
+		local t1 = h + s1 + ch + k[i] + w[i]
+		h, g, f, e, d, c, b, a = g, f, e, d + t1, c, b, a, t1 + t2
+	end
+
+	H[1] = band(H[1] + a)
+	H[2] = band(H[2] + b)
+	H[3] = band(H[3] + c)
+	H[4] = band(H[4] + d)
+	H[5] = band(H[5] + e)
+	H[6] = band(H[6] + f)
+	H[7] = band(H[7] + g)
+	H[8] = band(H[8] + h)
+end
+
+function sha256(msg)
+	msg = preproc(msg, #msg)
+	local H = initH256({})
+	for i = 1, #msg, 64 do digestblock(msg, i, H) end
+	return str2hexa(num2s(H[1], 4) .. num2s(H[2], 4) .. num2s(H[3], 4) .. num2s(H[4], 4) ..
+		num2s(H[5], 4) .. num2s(H[6], 4) .. num2s(H[7], 4) .. num2s(H[8], 4))
+end
+
+-- CJA 20230621: Encode directly to base64
+local BASE64 = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
+local function base64_6(n)
+	-- Helper: encode one single 6-bit number into base 64
+	return string.sub(BASE64, n + 1, n + 1)
+end
+local function base64_30(n)
+	-- Helper: encode five 6-bit numbers into base 64
+	return (base64_6(rshift(n, 24) % 64) ..
+		base64_6(rshift(n, 18) % 64) ..
+		base64_6(rshift(n, 12) % 64) ..
+		base64_6(rshift(n, 6) % 64) ..
+		base64_6(n % 64))
+end
+
+function sha256_base64(msg)
+	msg = preproc(msg, #msg)
+	local H = initH256({})
+	for i = 1, #msg, 64 do digestblock(msg, i, H) end
+	local b64 = (
+		-- Three bytes become four base 64 units. That means that:
+		-- Three 32-bit words become three 30-bit words plus a 6-bit unit.
+		base64_30(rshift(H[1], 2)) ..
+		base64_30(lshift(H[1] % 4, 28) + rshift(H[2], 4)) ..
+		base64_30(lshift(H[2] % 16, 26) + rshift(H[3], 6)) ..
+		base64_6(H[3] % 64) ..
+		base64_30(rshift(H[4], 2)) ..
+		base64_30(lshift(H[4] % 4, 28) + rshift(H[5], 4)) ..
+		base64_30(lshift(H[5] % 16, 26) + rshift(H[6], 6)) ..
+		base64_6(H[6] % 64) ..
+		-- We have a total of eight 32-bit words, so now we have to encode
+		-- two 32-bit words into two 30-bit words plus a 4-bit unit.
+		base64_30(rshift(H[7], 2)) ..
+		base64_30(lshift(H[7] % 4, 28) + rshift(H[8], 4)) ..
+		base64_6(lshift(H[8] % 16, 2)) .. '=')
+	return b64
+end
+
 function activate()
-	vlc.msg.dbg("[FadeMusic] Activated")
+	vlc.msg.dbg("[FadeMusic] Activated - pwd: " .. sha256_base64(PASSWORD))
 	sock = vlc.net.connect_tcp(HOST, PORT)
 	vlc.msg.dbg("[FadeMusic] Sock is " .. sock)
-	vlc.net.send(sock, "GET / HTTP/1.1\r\nHost: junk\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Key: asdf\r\nSec-WebSocket-Version: 13\r\n\r\n")
+	vlc.net.send(sock, "GET / HTTP/1.1\r\nHost: OBS\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Key: asdf\r\nSec-WebSocket-Version: 13\r\n\r\n")
 	local pollfds = {}
 	pollfds[sock] = vlc.net.POLLIN
 	vlc.net.poll(pollfds)
 	local chunk = vlc.net.recv(sock, 2048)
 	while chunk do
 		vlc.keep_alive()
-		vlc.msg.dbg(chunk)
-		if string.find(chunk, "quit") then break end
-		vlc.msg.dbg("[FadeMusic] Poll result: " .. vlc.net.poll(pollfds))
+		local pos = string.find(chunk, "\r\n\r\n")
+		if pos then
+			chunk = string.sub(chunk, pos)
+			break
+		end
+		vlc.net.poll(pollfds)
 		chunk = vlc.net.recv(sock, 2048)
 	end
+	vlc.msg.dbg(chunk)
 	vlc.net.close(sock)
 	vlc.deactivate()
 end