macaroons+rpcserver: Add new RPC call for checking macaroon permissions

lnrpc/lightning.swagger.json

@@ -1563,6 +1563,39 @@
         ]
       }
     },
+    "/v1/macaroon/checkpermissions": {
+      "post": {
+        "summary": "CheckMacaroonPermissions checks whether a request follows the constraints\nimposed on the macaroon and that the macaroon is authorized to follow the\nprovided permissions.",
+        "operationId": "Lightning_CheckMacaroonPermissions",
+        "responses": {
+          "200": {
+            "description": "A successful response.",
+            "schema": {
+              "$ref": "#/definitions/lnrpcCheckMacPermResponse"
+            }
+          },
+          "default": {
+            "description": "An unexpected error response.",
+            "schema": {
+              "$ref": "#/definitions/rpcStatus"
+            }
+          }
+        },
+        "parameters": [
+          {
+            "name": "body",
+            "in": "body",
+            "required": true,
+            "schema": {
+              "$ref": "#/definitions/lnrpcCheckMacPermRequest"
+            }
+          }
+        ],
+        "tags": [
+          "Lightning"
+        ]
+      }
+    },
     "/v1/macaroon/ids": {
       "get": {
         "summary": "lncli: `listmacaroonids`\nListMacaroonIDs returns all root key IDs that are in use.",
@@ -3622,6 +3655,32 @@
         }
       }
     },
+    "lnrpcCheckMacPermRequest": {
+      "type": "object",
+      "properties": {
+        "macaroon": {
+          "type": "string",
+          "format": "byte"
+        },
+        "permissions": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/lnrpcMacaroonPermission"
+          }
+        },
+        "fullMethod": {
+          "type": "string"
+        }
+      }
+    },
+    "lnrpcCheckMacPermResponse": {
+      "type": "object",
+      "properties": {
+        "valid": {
+          "type": "boolean"
+        }
+      }
+    },
     "lnrpcCloseStatusUpdate": {
       "type": "object",
       "properties": {