perms: add IsWhiteListURL method to the Manager

This commit adds a new `IsWhiteListURL` to the permissions manager. This
can then be used by LiT to check if it should perform macaroon
validation on a query or not.

Author: ellemouton

perms/manager.go

@@ -49,8 +49,13 @@ func NewManager(withAllSubServers bool) (*Manager, error) {
 	permissions := make(map[string]map[string][]bakery.Op)
 	permissions[litPerms] = RequiredPermissions
 	permissions[lndPerms] = lnd.MainRPCServerPermissions()
-	for k, v := range whiteListedLNDMethods {
-		permissions[lndPerms][k] = v
+
+	for url := range whiteListedLitMethods {
+		permissions[litPerms][url] = []bakery.Op{}
+	}
+
+	for url := range whiteListedLNDMethods {
+		permissions[lndPerms][url] = []bakery.Op{}
 	}
 
 	// Collect all LND sub-server permissions along with the name of the
@@ -96,6 +101,18 @@ func NewManager(withAllSubServers bool) (*Manager, error) {
 	}, nil
 }
 
+// IsWhiteListedURL returns true if the given URL has been whitelisted meaning
+// that it does not require a macaroon for validation. A URL is considered
+// white-listed if it has no operations associated with a URL.
+func (pm *Manager) IsWhiteListedURL(url string) bool {
+	pm.permsMu.Lock()
+	defer pm.permsMu.Unlock()
+
+	ops, ok := pm.perms[url]
+
+	return ok && len(ops) == 0
+}
+
 // RegisterSubServer adds the permissions of a given sub-server to the set
 // managed by the Manager.
 func (pm *Manager) RegisterSubServer(name string,

perms/permissions.go

@@ -80,7 +80,7 @@ var (
 
 	// whiteListedLNDMethods is a map of all lnd RPC methods that don't
 	// require any macaroon authentication.
-	whiteListedLNDMethods = map[string][]bakery.Op{
+	whiteListedLNDMethods = map[string]struct{}{
 		"/lnrpc.WalletUnlocker/GenSeed":        {},
 		"/lnrpc.WalletUnlocker/InitWallet":     {},
 		"/lnrpc.WalletUnlocker/UnlockWallet":   {},
@@ -92,6 +92,10 @@ var (
 		"/lnrpc.State/GetState":       {},
 	}
 
+	// whiteListedLitMethods is a map of all LiT's RPC methods that don't
+	// require any macaroon authentication.
+	whiteListedLitMethods = map[string]struct{}{}
+
 	// lndSubServerNameToTag is a map from the name of an LND subserver to
 	// the name of the LND tag that corresponds to the subserver. This map
 	// only contains the subserver-to-tag pairs for the pairs where the