certificate := r.TLS.PeerCertificates[0]
	if !globalIAMSys.STSTLSConfig.InsecureSkipVerify { // Verify whether the client certificate has been issued by a trusted CA.
		_, err := certificate.Verify(x509.VerifyOptions{
			KeyUsages: []x509.ExtKeyUsage{
				x509.ExtKeyUsageClientAuth,
			},
			Roots: globalRootCAs,
		})
		if err != nil {
			writeSTSErrorResponse(ctx, w, ErrSTSInvalidClientCertificate, err)
			return
		}

pkg crypto/x509, type Certificate struct, IPAddresses []net.IP
pkg crypto/x509, type PEMCipher int
pkg crypto/x509, type SystemRootsError struct
pkg crypto/x509, type VerifyOptions struct, KeyUsages []ExtKeyUsage
pkg crypto/x509, var IncorrectPasswordError error
pkg database/sql, method (*DB) Ping() error
pkg database/sql, method (*DB) SetMaxIdleConns(int)
pkg database/sql/driver, type Queryer interface { Query }