DATA p256ord<>+0x18(SB)/8, $0xf3b9cac2fc632551
DATA p256<>+0x00(SB)/8, $0xffffffff00000001 // P256
DATA p256<>+0x08(SB)/8, $0x0000000000000000 // P256
DATA p256<>+0x10(SB)/8, $0x00000000ffffffff // P256
DATA p256<>+0x18(SB)/8, $0xffffffffffffffff // P256
DATA p256<>+0x20(SB)/8, $0x0c0d0e0f1c1d1e1f // SEL d1 d0 d1 d0
DATA p256<>+0x28(SB)/8, $0x0c0d0e0f1c1d1e1f // SEL d1 d0 d1 d0
DATA p256<>+0x30(SB)/8, $0x0000000010111213 // SEL 0  d1 d0  0

// on little endian.
DATA p256<>+0x00(SB)/8, $0xffffffff00000001 // P256
DATA p256<>+0x08(SB)/8, $0x0000000000000000 // P256
DATA p256<>+0x10(SB)/8, $0x00000000ffffffff // P256
DATA p256<>+0x18(SB)/8, $0xffffffffffffffff // P256
DATA p256<>+0x20(SB)/8, $0x0c0d0e0f1c1d1e1f // SEL d1 d0 d1 d0
DATA p256<>+0x28(SB)/8, $0x0c0d0e0f1c1d1e1f // SEL d1 d0 d1 d0
DATA p256<>+0x30(SB)/8, $0x0000000010111213 // SEL 0  d1 d0  0

	if a != want {
		t.Errorf("zero256u2 got=%v, want %v\n", a, want)
	}

			benchmarkHandshakeServer(b, VersionTLS12, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
				CurveP256, testRSACertificate, testRSAPrivateKey)
		})
	})
	b.Run("ECDHE-P256-ECDSA-P256", func(b *testing.B) {
		b.Run("TLSv13", func(b *testing.B) {
			benchmarkHandshakeServer(b, VersionTLS13, TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,
				CurveP256, testP256Certificate, testP256PrivateKey)
		})

	case oid.Equal(oidNamedCurveP256):
		return elliptic.P256()
	case oid.Equal(oidNamedCurveP384):
		return elliptic.P384()
	case oid.Equal(oidNamedCurveP521):
		return elliptic.P521()
	}
	return nil
}

func oidFromNamedCurve(curve elliptic.Curve) (asn1.ObjectIdentifier, bool) {
	switch curve {
	case elliptic.P224():
		return oidNamedCurveP224, true
	case elliptic.P256():
		return oidNamedCurveP256, true

				}
				if cs.testingOnlyDidHRR {
					t.Error("client used HRR")
				}
			}
		})
	}
}

func TestX509KeyPairPopulateCertificate(t *testing.T) {
	key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
	if err != nil {
		t.Fatal(err)
	}
	keyDER, err := x509.MarshalPKCS8PrivateKey(key)
	if err != nil {
		t.Fatal(err)
	}

	runClientTestTLS13(t, test)
}

func TestHandshakeClientP256(t *testing.T) {
	config := testConfig.Clone()
	config.CurvePreferences = []CurveID{CurveP256}

	test := &clientTest{
		name:   "P256-ECDHE",
		args:   []string{"-cipher", "ECDHE-RSA-AES128-GCM-SHA256", "-curves", "P-256"},
		config: config,
	}

	runClientTestTLS12(t, test)
	runClientTestTLS13(t, test)
}

  // Use, run, and verify
  TF_Operation* func_feed = Placeholder(host_graph_, s_);
  TF_Operation* func_op = Use({func_feed});
  RunT({{func_feed, Int32Tensor({1, 2, 3, 4, 5, 6})}},
       {{func_op, 0}, {func_op, 1}}, {{1, 2}, {5, 6}});
  VerifyFDef({"split3_const0", "split3_1"}, M({{"feed"}}),
             M({{"split3"}, {"split3_0"}}),
             {{"split3_const0:output:0", "split3_1:0"},
              {"feed", "split3_1:1"},

	var ecdsaCipherSuite bool
	if priv, ok := c.PrivateKey.(crypto.Signer); ok {
		switch pub := priv.Public().(type) {
		case *ecdsa.PublicKey:
			var curve CurveID
			switch pub.Curve {
			case elliptic.P256():
				curve = CurveP256
			case elliptic.P384():
				curve = CurveP384
			case elliptic.P521():
				curve = CurveP521
			default:
				return supportsRSAFallback(unsupportedCertificateError(c))
			}

			in:   func() string { return "" },
			want: "",
		},
		{
			name: "valid certificate authority",
			in: func() string {
				caPrivateKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
				if err != nil {
					t.Fatal(err)
				}
				caCert, err := certutil.NewSelfSignedCACert(certutil.Config{CommonName: "test-ca"}, caPrivateKey)
				if err != nil {
					t.Fatal(err)
				}