if len(chain) == 0 {
		return nil, errors.New("x509: internal error: system verifier returned an empty chain")
	}

	// Mitigate CVE-2020-0601, where the Windows system verifier might be
	// tricked into using custom curve parameters for a trusted root, by
	// double-checking all ECDSA signatures. If the system was tricked into
	// using spoofed parameters, the signature will be invalid for the correct

	runServerTestTLS13(t, test)
}

func benchmarkHandshakeServer(b *testing.B, version uint16, cipherSuite uint16, curve CurveID, cert []byte, key crypto.PrivateKey) {
	config := testConfig.Clone()
	config.CipherSuites = []uint16{cipherSuite}
	config.CurvePreferences = []CurveID{curve}
	config.Certificates = make([]Certificate, 1)
	config.Certificates[0].Certificate = [][]byte{cert}

	p.y.Set(q.y)
	p.z.Set(q.z)
	return p
}

// SetBytes sets p to the compressed, uncompressed, or infinity value encoded in
// b, as specified in SEC 1, Version 2.0, Section 2.3.4. If the point is not on
// the curve, it returns nil and an error, and the receiver is unchanged.
// Otherwise, it returns p.
func (p *P256Point) SetBytes(b []byte) (*P256Point, error) {
	switch {
	// Point at infinity.
	case len(b) == 1 && b[0] == 0:

		c.sendAlert(alertInternalError)
		return errors.New("tls: CurvePreferences includes unsupported curve")
	}
	key, err := generateECDHEKey(c.config.rand(), ecdhGroup)
	if err != nil {
		c.sendAlert(alertInternalError)
		return err
	}
	hs.hello.serverShare = keyShare{group: selectedGroup, data: key.PublicKey().Bytes()}
	peerKey, err := key.Curve().NewPublicKey(ecdhData)
	if err != nil {
		c.sendAlert(alertIllegalParameter)

	p.y.Set(q.y)
	p.z.Set(q.z)
	return p
}

// SetBytes sets p to the compressed, uncompressed, or infinity value encoded in
// b, as specified in SEC 1, Version 2.0, Section 2.3.4. If the point is not on
// the curve, it returns nil and an error, and the receiver is unchanged.
// Otherwise, it returns p.
func (p *P384Point) SetBytes(b []byte) (*P384Point, error) {
	switch {
	// Point at infinity.
	case len(b) == 1 && b[0] == 0:

	p.y.Set(q.y)
	p.z.Set(q.z)
	return p
}

// SetBytes sets p to the compressed, uncompressed, or infinity value encoded in
// b, as specified in SEC 1, Version 2.0, Section 2.3.4. If the point is not on
// the curve, it returns nil and an error, and the receiver is unchanged.
// Otherwise, it returns p.
func (p *P224Point) SetBytes(b []byte) (*P224Point, error) {
	switch {
	// Point at infinity.
	case len(b) == 1 && b[0] == 0:

	p.y.Set(q.y)
	p.z.Set(q.z)
	return p
}

// SetBytes sets p to the compressed, uncompressed, or infinity value encoded in
// b, as specified in SEC 1, Version 2.0, Section 2.3.4. If the point is not on
// the curve, it returns nil and an error, and the receiver is unchanged.
// Otherwise, it returns p.
func (p *P521Point) SetBytes(b []byte) (*P521Point, error) {
	switch {
	// Point at infinity.
	case len(b) == 1 && b[0] == 0:

	eccSigAlgEnv        = env.Register("ECC_SIGNATURE_ALGORITHM", "", "The type of ECC signature algorithm to use when generating private keys").Get()
	eccCurvEnv          = env.Register("ECC_CURVE", "P256", "The elliptic curve to use when ECC_SIGNATURE_ALGORITHM is set to ECDSA").Get()
	fileMountedCertsEnv = env.Register("FILE_MOUNTED_CERTS", false, "").Get()
	credFetcherTypeEnv  = env.Register("CREDENTIAL_FETCHER_TYPE", security.JWT,

	HasVX     bool // vector facility. Note: the runtime sets this when it processes auxv records.
	HasVXE    bool // vector-enhancements facility 1
	HasKDSA   bool // elliptic curve functions
	HasECDSA  bool // NIST curves
	HasEDDSA  bool // Edwards curves
	_         CacheLinePad
}

// CPU feature variables are accessed by assembly code in various packages.
//go:linkname X86

			return c.Name
		}
	}
	return fmt.Sprintf("0x%04X", id)
}

const (
	// suiteECDHE indicates that the cipher suite involves elliptic curve
	// Diffie-Hellman. This means that it should only be selected when the
	// client indicates that it supports ECC with a curve and point format
	// that we're happy with.
	suiteECDHE = 1 << iota
	// suiteECSign indicates that the cipher suite involves an ECDSA or