Change structure of code to a frontend and backend one

cmd/backend/sessions.go

@@ -0,0 +1,61 @@
+package backend
+
+import (
+	"crypto/rand"
+	"encoding/gob"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/gorilla/sessions"
+)
+
+type CookieStore struct {
+	sessions.CookieStore
+}
+
+func NewKey() ([]byte, error) {
+	key := make([]byte, 32)
+
+	if _, err := io.ReadFull(rand.Reader, key); err != nil {
+		return nil, fmt.Errorf("error generating key: %v", err)
+	}
+
+	return key, nil
+}
+
+func SaveKey(key []byte, filename string) error {
+	file, err := os.Create(filename)
+	if err != nil {
+		return fmt.Errorf("error creating key file: %v", err)
+	}
+	defer file.Close()
+	file.Chmod(0600)
+
+	if err = gob.NewEncoder(file).Encode(key); err != nil {
+		return fmt.Errorf("error ecoding key: %v", err)
+	}
+
+	return nil
+}
+
+func LoadKey(filename string) ([]byte, error) {
+	file, err := os.Open(filename)
+	if err != nil {
+		return nil, fmt.Errorf("error opening key file: %v", err)
+	}
+
+	key := make([]byte, 32)
+	if err = gob.NewDecoder(file).Decode(&key); err != nil {
+		return nil, fmt.Errorf("error decoding key: %v", err)
+	}
+
+	return key, nil
+}
+
+func NewCookieStore(key []byte) *CookieStore {
+	store := sessions.NewCookieStore(key)
+	store.Options.Secure = true
+	store.Options.HttpOnly = true
+	return &CookieStore{*store}
+}