Add ability to autogen self-signed x509 certs for use with Grumble.

Makefile

@@ -38,7 +38,8 @@ GOFILES = \
 	group.go \
 	user.go \
 	murmurdb.go \
-	freeze.go
+	freeze.go \
+	gencert.go
 
 .PHONY: grumble
 grumble: pkg

gencert.go

@@ -0,0 +1,79 @@
+// Copyright (c) 2011 The Grumble Authors
+// The use of this source code is goverened by a BSD-style
+// license that can be found in the LICENSE-file.
+
+package main
+
+import (
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/pem"
+	"log"
+	"os"
+	"path/filepath"
+	"time"
+)
+
+// Generate a 2048-bit RSA keypair and a Grumble auto-generated X509
+// certificate. Output PEM-encoded DER representations of the resulting
+// certificate and private key to certpath and keypath.
+func GenerateSelfSignedCert(certpath, keypath string) (err os.Error) {
+	now := time.Seconds()
+	tmpl := &x509.Certificate{
+		SerialNumber: []byte{0},
+		Subject: x509.Name{
+			CommonName: "Grumble Autogenerated Certificate",
+		},
+		NotBefore: time.SecondsToUTC(now - 300),
+		NotAfter:  time.SecondsToUTC(now + 60*60*24*365), // valid for 1 year.
+
+		SubjectKeyId: []byte{1, 2, 3, 4},
+		KeyUsage:     x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
+	}
+
+	priv, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		return err
+	}
+
+	certbuf, err := x509.CreateCertificate(rand.Reader, tmpl, tmpl, &priv.PublicKey, priv)
+	if err != nil {
+		log.Printf("Error: %v", err)
+		return err
+	}
+	certblk := pem.Block{
+		Type:  "CERTIFICATE",
+		Bytes: certbuf,
+	}
+
+	keybuf := x509.MarshalPKCS1PrivateKey(priv)
+	keyblk := pem.Block{
+		Type:  "RSA PRIVATE KEY",
+		Bytes: keybuf,
+	}
+
+	certfn := filepath.Join(*datadir, "cert")
+	file, err := os.OpenFile(certfn, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0700)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	err = pem.Encode(file, &certblk)
+	if err != nil {
+		return err
+	}
+
+	keyfn := filepath.Join(*datadir, "key")
+	file, err = os.OpenFile(keyfn, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0700)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	err = pem.Encode(file, &keyblk)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

grumble.go

@@ -24,6 +24,7 @@ var datadir *string = flag.String("datadir", "", "Directory to use for server st
 var blobdir *string = flag.String("blobdir", "", "Directory to use for blob storage")
 var sqlitedb *string = flag.String("murmurdb", "", "Path to murmur.sqlite to import server structure from")
 var cleanup *bool = flag.Bool("clean", false, "Clean up existing data dir content before importing Murmur data")
+var gencert *bool = flag.Bool("gencert", false, "Generate a self-signed certificate for use with Grumble")
 
 var globalBlobstore *blobstore.BlobStore
 
@@ -94,6 +95,26 @@ func main() {
 		log.Fatalf("Unable to initialize blobstore: %v", err.String())
 	}
 
+	// Generate a cert?
+	if *gencert {
+		certfn := filepath.Join(*datadir, "cert")
+		keyfn := filepath.Join(*datadir, "key")
+		log.Printf("Generating 2048-bit RSA keypair for self-signed certificate...")
+
+		err := GenerateSelfSignedCert(certfn, keyfn)
+		if err != nil {
+			log.Printf("Error: %v", err)
+			return
+		}
+
+		log.Printf("Certificate output to %v", certfn)
+		log.Printf("Private key output to %v", keyfn)
+
+		log.Printf("Done generating certificate and private key.")
+		log.Printf("Please restart Grumble to make use of the generated certificate and private key.")
+		return
+	}
+
 	// Should we import data from a Murmur SQLite file?
 	if len(*sqlitedb) > 0 {
 		f, err := os.Open(*datadir)

tlsserver.go

@@ -9,13 +9,14 @@ import (
 	"encoding/pem"
 	"crypto/x509"
 	"io/ioutil"
+	"path/filepath"
 )
 
 func NewTLSListener(port int) (rl *tls.Listener) {
 	rl = nil
 
 	// Load the certificate
-	pemBytes, err := ioutil.ReadFile("grumble.crt")
+	pemBytes, err := ioutil.ReadFile(filepath.Join(*datadir, "cert"))
 	if err != nil {
 		log.Printf("Failed to read server.crt: %s", err)
 		return
@@ -29,7 +30,7 @@ func NewTLSListener(port int) (rl *tls.Listener) {
 	}
 
 	// Load the private key
-	keyBytes, err := ioutil.ReadFile("grumble.key")
+	keyBytes, err := ioutil.ReadFile(filepath.Join(*datadir, "key"))
 	if err != nil {
 		log.Printf("Failed to read server.key.insecure: %s", err)
 		return