local testimony = require("testimony")
local litls = require("litls.core")

local hex = litls.hex_encode
local unhex = litls.hex_decode

local testify = testimony.new("== LITLS HKDF ==")

-- RFC 5869 Appendix A test vectors

testify:that("HKDF-SHA256 test case 1", function()
	local ikm = unhex("0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b")
	local salt = unhex("000102030405060708090a0b0c")
	local info = unhex("f0f1f2f3f4f5f6f7f8f9")

	local prk = litls.hkdf_extract_sha256(salt, ikm)
	testimony.assert_equal("077709362c2e32df0ddc3f0dc47bba6390b6c73bb50f9c3122ec844ad7c2b3e5", hex(prk))

	local okm = litls.hkdf_expand_sha256(prk, info, 42)
	testimony.assert_equal(
		"3cb25f25faacd57a90434f64d0362f2a2d2d0a90cf1a5a4c5db02d56ecc4c5bf34007208d5b887185865",
		hex(okm)
	)
end)

testify:that("HKDF-SHA256 test case 2 (longer inputs)", function()
	local ikm = unhex(
		"000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f"
	)
	local salt = unhex(
		"606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeaf"
	)
	local info = unhex(
		"b0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff"
	)

	local prk = litls.hkdf_extract_sha256(salt, ikm)
	testimony.assert_equal("06a6b88c5853361a06104c9ceb35b45cef760014904671014a193f40c15fc244", hex(prk))

	local okm = litls.hkdf_expand_sha256(prk, info, 82)
	testimony.assert_equal(
		"b11e398dc80327a1c8e7f78c596a49344f012eda2d4efad8a050cc4c19afa97c59045a99cac7827271cb41c65e590e09da3275600c2f09b8367793a9aca3db71cc30c58179ec3e87c14c01d5c1f3434f1d87",
		hex(okm)
	)
end)

testify:that("HKDF-SHA256 test case 3 (zero-length salt/info)", function()
	local ikm = unhex("0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b")
	local salt = ""
	local info = ""

	local prk = litls.hkdf_extract_sha256(salt, ikm)
	testimony.assert_equal("19ef24a32c717b167f33a91d6f648bdf96596776afdb6377ac434c1c293ccb04", hex(prk))

	local okm = litls.hkdf_expand_sha256(prk, info, 42)
	testimony.assert_equal(
		"8da4e775a563c18f715f802a063c5a31b8a11f5c5ee1879ec3454e5f3c738d2d9d201395faa4b61a96c8",
		hex(okm)
	)
end)

testify:conclude()