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package tlsconfig
import (
"crypto/tls"
"crypto/x509"
"fmt"
"io/ioutil"
"runtime"
"sync"
"github.com/getsentry/raven-go"
"github.com/pkg/errors"
"github.com/rs/zerolog"
"github.com/urfave/cli/v2"
)
const (
OriginCAPoolFlag = "origin-ca-pool"
CaCertFlag = "cacert"
)
// CertReloader can load and reload a TLS certificate from a particular filepath.
// Hooks into tls.Config's GetCertificate to allow a TLS server to update its certificate without restarting.
type CertReloader struct {
sync.Mutex
certificate *tls.Certificate
certPath string
keyPath string
}
// NewCertReloader makes a CertReloader. It loads the cert during initialization to make sure certPath and keyPath are valid
func NewCertReloader(certPath, keyPath string) (*CertReloader, error) {
cr := new(CertReloader)
cr.certPath = certPath
cr.keyPath = keyPath
if err := cr.LoadCert(); err != nil {
return nil, err
}
return cr, nil
}
// Cert returns the TLS certificate most recently read by the CertReloader.
func (cr *CertReloader) Cert(clientHello *tls.ClientHelloInfo) (*tls.Certificate, error) {
cr.Lock()
defer cr.Unlock()
return cr.certificate, nil
}
// LoadCert loads a TLS certificate from the CertReloader's specified filepath.
// Call this after writing a new certificate to the disk (e.g. after renewing a certificate)
func (cr *CertReloader) LoadCert() error {
cr.Lock()
defer cr.Unlock()
cert, err := tls.LoadX509KeyPair(cr.certPath, cr.keyPath)
// Keep the old certificate if there's a problem reading the new one.
if err != nil {
raven.CaptureError(fmt.Errorf("Error parsing X509 key pair: %v", err), nil)
return err
}
cr.certificate = &cert
return nil
}
func LoadOriginCA(originCAPoolFilename string, log *zerolog.Logger) (*x509.CertPool, error) {
var originCustomCAPool []byte
if originCAPoolFilename != "" {
var err error
originCustomCAPool, err = ioutil.ReadFile(originCAPoolFilename)
if err != nil {
return nil, errors.Wrap(err, fmt.Sprintf("unable to read the file %s for --%s", originCAPoolFilename, OriginCAPoolFlag))
}
}
originCertPool, err := loadOriginCertPool(originCustomCAPool, log)
if err != nil {
return nil, errors.Wrap(err, "error loading the certificate pool")
}
// Windows users should be notified that they can use the flag
if runtime.GOOS == "windows" && originCAPoolFilename == "" {
log.Info().Msgf("cloudflared does not support loading the system root certificate pool on Windows. Please use --%s <PATH> to specify the path to the certificate pool", OriginCAPoolFlag)
}
return originCertPool, nil
}
func LoadCustomOriginCA(originCAFilename string) (*x509.CertPool, error) {
// First, obtain the system certificate pool
certPool, err := x509.SystemCertPool()
if err != nil {
certPool = x509.NewCertPool()
}
// Next, append the Cloudflare CAs into the system pool
cfRootCA, err := GetCloudflareRootCA()
if err != nil {
return nil, errors.Wrap(err, "could not append Cloudflare Root CAs to cloudflared certificate pool")
}
for _, cert := range cfRootCA {
certPool.AddCert(cert)
}
if originCAFilename == "" {
return certPool, nil
}
customOriginCA, err := ioutil.ReadFile(originCAFilename)
if err != nil {
return nil, errors.Wrap(err, fmt.Sprintf("unable to read the file %s", originCAFilename))
}
if !certPool.AppendCertsFromPEM(customOriginCA) {
return nil, fmt.Errorf("error appending custom CA to cert pool")
}
return certPool, nil
}
func CreateTunnelConfig(c *cli.Context, serverName string) (*tls.Config, error) {
var rootCAs []string
if c.String(CaCertFlag) != "" {
rootCAs = append(rootCAs, c.String(CaCertFlag))
}
userConfig := &TLSParameters{RootCAs: rootCAs, ServerName: serverName}
tlsConfig, err := GetConfig(userConfig)
if err != nil {
return nil, err
}
if tlsConfig.RootCAs == nil {
rootCAPool := x509.NewCertPool()
cfRootCA, err := GetCloudflareRootCA()
if err != nil {
return nil, errors.Wrap(err, "could not append Cloudflare Root CAs to cloudflared certificate pool")
}
for _, cert := range cfRootCA {
rootCAPool.AddCert(cert)
}
tlsConfig.RootCAs = rootCAPool
}
if tlsConfig.ServerName == "" && !tlsConfig.InsecureSkipVerify {
return nil, fmt.Errorf("either ServerName or InsecureSkipVerify must be specified in the tls.Config")
}
return tlsConfig, nil
}
func loadOriginCertPool(originCAPoolPEM []byte, log *zerolog.Logger) (*x509.CertPool, error) {
// Get the global pool
certPool, err := loadGlobalCertPool(log)
if err != nil {
return nil, err
}
// Then, add any custom origin CA pool the user may have passed
if originCAPoolPEM != nil {
if !certPool.AppendCertsFromPEM(originCAPoolPEM) {
log.Info().Msg("could not append the provided origin CA to the cloudflared certificate pool")
}
}
return certPool, nil
}
func loadGlobalCertPool(log *zerolog.Logger) (*x509.CertPool, error) {
// First, obtain the system certificate pool
certPool, err := x509.SystemCertPool()
if err != nil {
if runtime.GOOS != "windows" { // See https://github.com/golang/go/issues/16736
log.Err(err).Msg("error obtaining the system certificates")
}
certPool = x509.NewCertPool()
}
// Next, append the Cloudflare CAs into the system pool
cfRootCA, err := GetCloudflareRootCA()
if err != nil {
return nil, errors.Wrap(err, "could not append Cloudflare Root CAs to cloudflared certificate pool")
}
for _, cert := range cfRootCA {
certPool.AddCert(cert)
}
// Finally, add the Hello certificate into the pool (since it's self-signed)
helloCert, err := GetHelloCertificateX509()
if err != nil {
return nil, errors.Wrap(err, "could not append Hello server certificate to cloudflared certificate pool")
}
certPool.AddCert(helloCert)
return certPool, nil
}