examples/server: Generate new certificates when they expire

examples/cert.go

@@ -12,7 +12,7 @@ import (
 func main() {
 	host := "localhost"
 
-	duration := 365 * 24 * time.Hour
+	duration := 2 * time.Minute
 	crt, key, err := gmi.NewRawCertificate(host, duration)
 	if err != nil {
 		log.Fatal(err)

examples/server.go

@@ -3,7 +3,9 @@
 package main
 
 import (
+	"crypto/tls"
 	"log"
+	"time"
 
 	"git.sr.ht/~adnano/gmi"
 )
@@ -13,6 +15,33 @@ func main() {
 	if err := server.CertificateStore.Load("/var/lib/gemini/certs"); err != nil {
 		log.Fatal(err)
 	}
+	server.GetCertificate = func(hostname string, store *gmi.CertificateStore) *tls.Certificate {
+		cert, err := store.Lookup(hostname)
+		if err != nil {
+			switch err {
+			case gmi.ErrInvalidCertificate:
+				log.Print("Old certificate expired, creating new one")
+				// Generate a new certificate if the old one is expired.
+				crt, key, err := gmi.NewRawCertificate(hostname, time.Minute)
+				if err != nil {
+					// Failed to generate new certificate, abort
+					return nil
+				}
+				// Store and return the new certificate
+				err = gmi.WriteX509KeyPair("/var/lib/gemini/certs/"+hostname, crt, key)
+				if err != nil {
+					return nil
+				}
+				newCert, err := tls.X509KeyPair(crt, key)
+				if err != nil {
+					return nil
+				}
+				store.Add(hostname, newCert)
+				return &newCert
+			}
+		}
+		return cert
+	}
 
 	var mux gmi.ServeMux
 	mux.Handle("/", gmi.FileServer(gmi.Dir("/var/www")))