feat: sign of file

pkg/sign/sign.go

@@ -0,0 +1,15 @@
+package sign
+
+import "errors"
+
+type Sign interface {
+	Sign(data string, expire int64) string
+	Verify(data, sign string) error
+}
+
+var (
+	ErrSignExpired   = errors.New("sign expired")
+	ErrSignInvalid   = errors.New("sign invalid")
+	ErrExpireInvalid = errors.New("expire invalid")
+	ErrExpireMissing = errors.New("expire missing")
+)