p2p-keygen: key generator for persistent identities

identity.go

@@ -21,5 +21,5 @@ func WriteIdentity(k crypto.PrivKey, path string) error {
 		return err
 	}
 
-	return ioutil.WriteFile(path, bytes, 0500)
+	return ioutil.WriteFile(path, bytes, 0400)
 }

p2p-keygen/main.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+
+	p2pd "github.com/libp2p/go-libp2p-daemon"
+
+	crypto "github.com/libp2p/go-libp2p-crypto"
+	peer "github.com/libp2p/go-libp2p-peer"
+)
+
+func main() {
+	file := flag.String("f", "identity", "output key file")
+	ktype := flag.String("t", "rsa", "key type; rsa or ed25519")
+	bits := flag.Int("b", 2048, "key size in bits (for rsa)")
+	flag.Parse()
+
+	var typ int
+
+	switch *ktype {
+	case "rsa":
+		typ = crypto.RSA
+
+	case "ed25519":
+		typ = crypto.Ed25519
+
+	default:
+		log.Fatalf("Unknown key type %s; must be rsa or ed25519", *ktype)
+	}
+
+	priv, pub, err := crypto.GenerateKeyPair(typ, *bits)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	id, err := peer.IDFromPublicKey(pub)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("Peer ID: %s\n", id.Pretty())
+
+	err = p2pd.WriteIdentity(priv, *file)
+	if err != nil {
+		log.Fatal(err)
+	}
+}