⚙️ Add wip/experimental peerguard and peergater

Peerguard and peergater are two components that work together to gate
peers and add them to a trusted zone.

This allows to isolate nodes from the p2p network and avoid to rotate
network tokens in case of leaks.

For the moment an ECDSA auth provider is implemented as sample purpose,
documentation will follow up on how to use them and how to write them
up.

api/api.go

@@ -66,6 +66,7 @@ const (
 	DNSURL        = "/api/dns"
 	MetricsURL    = "/api/metrics"
 	PeerstoreURL  = "/api/peerstore"
+	PeerGateURL   = "/api/peergate"
 )
 
 func API(ctx context.Context, l string, defaultInterval, timeout time.Duration, e *node.Node, bwc metrics.Reporter, debugMode bool) error {
@@ -115,6 +116,24 @@ func API(ctx context.Context, l string, defaultInterval, timeout time.Duration,
 		return c.JSON(http.StatusOK, list)
 	})
 
+	if e.PeerGater() != nil {
+		ec.PUT(fmt.Sprintf("%s/:state", PeerGateURL), func(c echo.Context) error {
+			state := c.Param("state")
+
+			switch state {
+			case "enable":
+				e.PeerGater().Enable()
+			case "disable":
+				e.PeerGater().Disable()
+			}
+			return c.JSON(http.StatusOK, e.PeerGater().Enabled())
+		})
+
+		ec.GET(PeerGateURL, func(c echo.Context) error {
+			return c.JSON(http.StatusOK, e.PeerGater().Enabled())
+		})
+	}
+
 	ec.GET(SummaryURL, func(c echo.Context) error {
 		files := len(ledger.CurrentData()[protocol.FilesLedgerKey])
 		machines := len(ledger.CurrentData()[protocol.MachinesLedgerKey])