Move cookie to pkg/encryption

pkg/encryption/nonce.go

@@ -0,0 +1,17 @@
+package encryption
+
+import (
+	"crypto/rand"
+	"fmt"
+)
+
+// Nonce generates a random 16 byte string to be used as a nonce
+func Nonce() (nonce string, err error) {
+	b := make([]byte, 16)
+	_, err = rand.Read(b)
+	if err != nil {
+		return
+	}
+	nonce = fmt.Sprintf("%x", b)
+	return
+}