TUN-528: Move cloudflared into a separate repo

tlsconfig/certreloader.go

@@ -0,0 +1,62 @@
+package tlsconfig
+
+import (
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"sync"
+
+	tunnellog "github.com/cloudflare/cloudflared/log"
+	"github.com/getsentry/raven-go"
+	log "github.com/sirupsen/logrus"
+	"gopkg.in/urfave/cli.v2"
+)
+
+// 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, memorizing the filepaths in the context/flags.
+func NewCertReloader(c *cli.Context, f CLIFlags) (*CertReloader, error) {
+	if !c.IsSet(f.Cert) {
+		return nil, errors.New("CertReloader: cert not provided")
+	}
+	if !c.IsSet(f.Key) {
+		return nil, errors.New("CertReloader: key not provided")
+	}
+	cr := new(CertReloader)
+	cr.certPath = c.String(f.Cert)
+	cr.keyPath = c.String(f.Key)
+	cr.LoadCert()
+	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() {
+	cr.Lock()
+	defer cr.Unlock()
+
+	log.SetFormatter(&tunnellog.JSONFormatter{})
+	log.Info("Reloading certificate")
+	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
+	}
+	cr.certificate = &cert
+}