keyring: Add key serialization

vault/keyring.go

@@ -35,6 +35,21 @@ type Key struct {
 	InstallTime time.Time
 }
 
+// Serialize is used to create a byte encoded key
+func (k *Key) Serialize() ([]byte, error) {
+	buf, err := json.Marshal(k)
+	return buf, err
+}
+
+// DeserializeKey is used to deserialize and return a new key
+func DeserializeKey(buf []byte) (*Key, error) {
+	k := new(Key)
+	if err := json.Unmarshal(buf, k); err != nil {
+		return nil, fmt.Errorf("deserialization failed: %v", err)
+	}
+	return k, nil
+}
+
 // NewKeyring creates a new keyring
 func NewKeyring() *Keyring {
 	k := &Keyring{

vault/keyring_test.go

@@ -171,3 +171,26 @@ func TestKeyring_Serialize(t *testing.T) {
 		}
 	}
 }
+
+func TestKey_Serialize(t *testing.T) {
+	k := &Key{
+		Term:        10,
+		Version:     1,
+		Value:       []byte("foobarbaz"),
+		InstallTime: time.Now(),
+	}
+
+	buf, err := k.Serialize()
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	out, err := DeserializeKey(buf)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if !reflect.DeepEqual(k, out) {
+		t.Fatalf("bad: %#v", out)
+	}
+}