feat: add fine-grained control for link signing (#3924)

* Determine whether the URL requires Sign

* Add File and Mem based KV

NOT TESTED: TokenKV Function

* Change Token KV func to common func.

Add File based KV func

* Remove KV, Remove Token

I found that the original Sign function is enough to complete the link signature, and only need to add simple configuration items to meet the requirements.

* Add IsStorageSigned func to judge if Signing is enabled in the storage settings.

It should be working now.

* Add a SIGN button to the management panel.

* Add enable_sign to the basic storage struct.

Can enable sign for every driver now.

Bug: When sign enabled, in download page, Copy link doesn't contain a sign.

(Not done yet)

* Fix a bug from commit 8f6c25f.

Response of fsread function does not contain sign.

* Optimize code and follow advices.

- Add back public/dist/README.md

- Enable sign when DownProxyUrl is enabled

- Merge needSign() to isEncrypt() in fsread.go

* simplify code

---------

Co-authored-by: Andy Hsu <i@nn.ci>

internal/model/storage.go

@@ -13,6 +13,7 @@ type Storage struct {
 	Remark          string    `json:"remark"`
 	Modified        time.Time `json:"modified"`
 	Disabled        bool      `json:"disabled"` // if disabled
+	EnableSign      bool      `json:"enable_sign"`
 	Sort
 	Proxy
 }

internal/op/driver.go

@@ -122,9 +122,14 @@ func getMainItems(config driver.Config) []driver.Item {
 		Type:    conf.TypeSelect,
 		Options: "front,back",
 	})
+	items = append(items, driver.Item{
+		Name:     "enable_sign",
+		Type:     conf.TypeBool,
+		Default:  "false",
+		Required: true,
+	})
 	return items
 }
-
 func getAdditionalItems(t reflect.Type, defaultRoot string) []driver.Item {
 	var items []driver.Item
 	for i := 0; i < t.NumField(); i++ {