text: import sys
  
  import pytest
  
  import mbedtls.hkdf as _hkdf
  import mbedtls.hmac as _hmac
  
  
  class TestHKDF:
      @pytest.fixture(params=[0, 128])
      def key(self, request, randbytes):
          return randbytes(request.param)
  
      @pytest.fixture(
          params=[
              # _hmac.md2,
              # _hmac.md4,
              _hmac.md5,
              _hmac.sha1,
              _hmac.sha224,
              _hmac.sha256,
              _hmac.sha384,
              _hmac.sha512,
              _hmac.ripemd160,
          ]
      )
      def hmac(self, request, key):
          return request.param
  
      @pytest.fixture
      def salt(self, hmac, key, randbytes):
          return randbytes(hmac(key).digest_size)
  
      @pytest.fixture(params=[16, 128, 500, 1000])
      def info(self, request, randbytes):
          return randbytes(request.param)
  
      @pytest.fixture(params=[16, 200, 500])
      def length(self, request):
          return request.param
  
      def test_hkdf(self, key):
          okm = _hkdf.hkdf(key, 32, b"")
          assert len(okm) == 32
  
      def test_hkdf_with_options(self, key, salt, info, hmac, length):
          okm = _hkdf.hkdf(key, length, info, salt, hmac)
          assert len(okm) == length
  
      def test_extract_and_expand(self, key):
          prk = _hkdf.extract(key)
          assert len(prk) == _hmac.sha256(b"").digest_size
  
          okm = _hkdf.expand(prk, 32, b"")
          assert len(okm) == 32
  
      def test_extract_and_expand_with_options(
          self, hmac, key, salt, info, length
      ):
          prk = _hkdf.extract(key, salt, hmac)
          assert len(prk) == hmac(b"").digest_size
  
          okm = _hkdf.expand(prk, length, info, hmac)
          assert len(okm) == length
  
  
  def to_bytes(number, size):
      return number.to_bytes(size, byteorder="big")
  
  
  @pytest.mark.skipif(
      sys.version_info < (3, 2), reason="int.to_bytes() requires Python 3.2+"
  )
  class TestHKDF_RFC5869_TestVectors:
      def test_case_1(self):
          algorithm = _hmac.sha256
          ikm = to_bytes(0x0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B, 22)
          salt = to_bytes(0x000102030405060708090A0B0C, 13)
          info = to_bytes(0xF0F1F2F3F4F5F6F7F8F9, 10)
          length = 42
          prk = to_bytes(
              int(
                  "0x077709362c2e32df0ddc3f0dc47bba63"
                  "90b6c73bb50f9c3122ec844ad7c2b3e5",
                  0,
              ),
              32,
          )
          okm = to_bytes(
              int(
                  "0x3cb25f25faacd57a90434f64d0362f2a"
                  "2d2d0a90cf1a5a4c5db02d56ecc4c5bf"
                  "34007208d5b887185865",
                  0,
              ),
              42,
          )
  
          assert _hkdf.extract(ikm, salt, algorithm) == prk
          assert _hkdf.expand(prk, length, info, algorithm) == okm
          assert _hkdf.hkdf(ikm, length, info, salt, algorithm) == okm
  
      def test_case_2(self):
          algorithm = _hmac.sha256
          ikm = to_bytes(
              int(
                  "0x000102030405060708090a0b0c0d0e0f"
                  "101112131415161718191a1b1c1d1e1f"
                  "202122232425262728292a2b2c2d2e2f"
                  "303132333435363738393a3b3c3d3e3f"
                  "404142434445464748494a4b4c4d4e4f",
                  0,
              ),
              80,
          )
          salt = to_bytes(
              int(
                  "0x606162636465666768696a6b6c6d6e6f"
                  "707172737475767778797a7b7c7d7e7f"
                  "808182838485868788898a8b8c8d8e8f"
                  "909192939495969798999a9b9c9d9e9f"
                  "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf",
                  0,
              ),
              80,
          )
          info = to_bytes(
              int(
                  "0xb0b1b2b3b4b5b6b7b8b9babbbcbdbebf"
                  "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf"
                  "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf"
                  "e0e1e2e3e4e5e6e7e8e9eaebecedeeef"
                  "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff",
                  0,
              ),
              80,
          )
          length = 82
          prk = to_bytes(
              int(
                  "0x06a6b88c5853361a06104c9ceb35b45c"
                  "ef760014904671014a193f40c15fc244",
                  0,
              ),
              32,
          )
          okm = to_bytes(
              int(
                  "0xb11e398dc80327a1c8e7f78c596a4934"
                  "4f012eda2d4efad8a050cc4c19afa97c"
                  "59045a99cac7827271cb41c65e590e09"
                  "da3275600c2f09b8367793a9aca3db71"
                  "cc30c58179ec3e87c14c01d5c1f3434f"
                  "1d87",
                  0,
              ),
              82,
          )
  
          assert _hkdf.extract(ikm, salt, algorithm) == prk
          assert _hkdf.expand(prk, length, info, algorithm) == okm
          assert _hkdf.hkdf(ikm, length, info, salt, algorithm) == okm
  
      def test_case_3(self):
          algorithm = _hmac.sha256
          ikm = to_bytes(0x0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B, 22)
          salt = b""
          info = b""
          length = 42
          prk = to_bytes(
              int(
                  "0x19ef24a32c717b167f33a91d6f648bdf"
                  "96596776afdb6377ac434c1c293ccb04",
                  0,
              ),
              32,
          )
          okm = to_bytes(
              int(
                  "0x8da4e775a563c18f715f802a063c5a31"
                  "b8a11f5c5ee1879ec3454e5f3c738d2d"
                  "9d201395faa4b61a96c8",
                  0,
              ),
              42,
          )
  
          assert _hkdf.extract(ikm, salt, algorithm) == prk
          assert _hkdf.expand(prk, length, info, algorithm) == okm
          assert _hkdf.hkdf(ikm, length, info, salt, algorithm) == okm
  
      def test_case_4(self):
          algorithm = _hmac.sha1
          ikm = to_bytes(0x0B0B0B0B0B0B0B0B0B0B0B, 11)
          salt = to_bytes(0x000102030405060708090A0B0C, 13)
          info = to_bytes(0xF0F1F2F3F4F5F6F7F8F9, 10)
          length = 42
          prk = to_bytes(0x9B6C18C432A7BF8F0E71C8EB88F4B30BAA2BA243, 20)
          okm = to_bytes(
              int(
                  "0x085a01ea1b10f36933068b56efa5ad81"
                  "a4f14b822f5b091568a9cdd4f155fda2"
                  "c22e422478d305f3f896",
                  0,
              ),
              42,
          )
  
          assert _hkdf.extract(ikm, salt, algorithm) == prk
          assert _hkdf.expand(prk, length, info, algorithm) == okm
          assert _hkdf.hkdf(ikm, length, info, salt, algorithm) == okm
  
      def test_case_5(self):
          algorithm = _hmac.sha1
          ikm = to_bytes(
              int(
                  "0x000102030405060708090a0b0c0d0e0f"
                  "101112131415161718191a1b1c1d1e1f"
                  "202122232425262728292a2b2c2d2e2f"
                  "303132333435363738393a3b3c3d3e3f"
                  "404142434445464748494a4b4c4d4e4f",
                  0,
              ),
              80,
          )
          salt = to_bytes(
              int(
                  "0x606162636465666768696a6b6c6d6e6f"
                  "707172737475767778797a7b7c7d7e7f"
                  "808182838485868788898a8b8c8d8e8f"
                  "909192939495969798999a9b9c9d9e9f"
                  "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf",
                  0,
              ),
              80,
          )
          info = to_bytes(
              int(
                  "0xb0b1b2b3b4b5b6b7b8b9babbbcbdbebf"
                  "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf"
                  "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf"
                  "e0e1e2e3e4e5e6e7e8e9eaebecedeeef"
                  "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff",
                  0,
              ),
              80,
          )
          length = 82
          prk = to_bytes(0x8ADAE09A2A307059478D309B26C4115A224CFAF6, 20)
          okm = to_bytes(
              int(
                  "0x0bd770a74d1160f7c9f12cd5912a06eb"
                  "ff6adcae899d92191fe4305673ba2ffe"
                  "8fa3f1a4e5ad79f3f334b3b202b2173c"
                  "486ea37ce3d397ed034c7f9dfeb15c5e"
                  "927336d0441f4c4300e2cff0d0900b52"
                  "d3b4",
                  0,
              ),
              82,
          )
  
          assert _hkdf.extract(ikm, salt, algorithm) == prk
          assert _hkdf.expand(prk, length, info, algorithm) == okm
          assert _hkdf.hkdf(ikm, length, info, salt, algorithm) == okm
  
      def test_case_6(self):
          algorithm = _hmac.sha1
          ikm = to_bytes(0x0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B0B, 22)
          salt = b""
          info = b""
          length = 42
          prk = to_bytes(0xDA8C8A73C7FA77288EC6F5E7C297786AA0D32D01, 20)
          okm = to_bytes(
              int(
                  "0x0ac1af7002b3d761d1e55298da9d0506"
                  "b9ae52057220a306e07b6b87e8df21d0"
                  "ea00033de03984d34918",
                  0,
              ),
              42,
          )
  
          assert _hkdf.extract(ikm, salt, algorithm) == prk
          assert _hkdf.expand(prk, length, info, algorithm) == okm
          assert _hkdf.hkdf(ikm, length, info, salt, algorithm) == okm
  
      def test_case_7(self):
          algorithm = _hmac.sha1
          ikm = to_bytes(0x0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C, 22)
          info = b""
          length = 42
          prk = to_bytes(0x2ADCCADA18779E7C2077AD2EB19D3F3E731385DD, 20)
          okm = to_bytes(
              int(
                  "0x2c91117204d745f3500d636a62f64f0a"
                  "b3bae548aa53d423b0d1f27ebba6f5e5"
                  "673a081d70cce7acfc48",
                  0,
              ),
              42,
          )
  
          assert _hkdf.extract(ikm, digestmod=algorithm) == prk
          assert _hkdf.expand(prk, length, info, algorithm) == okm
          assert _hkdf.hkdf(ikm, length, info, digestmod=algorithm) == okm
  