@metamask/snaps-rpc-methods
Version:
MetaMask Snaps JSON-RPC method implementations
97 lines • 3.7 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.messengerCallHandler = void 0;
const rpc_errors_1 = require("@metamask/rpc-errors");
const superstruct_1 = require("@metamask/superstruct");
const utils_1 = require("@metamask/utils");
const endowments_1 = require("../endowments/index.cjs");
const messenger_1 = require("../endowments/messenger.cjs");
const hookNames = {
getMessenger: true,
};
const BLOCKED_MESSENGER_CLIENTS = [
'ApprovalController',
'KeyringController',
'PermissionController',
'SnapController',
'WebSocketService',
'CronjobController',
'SnapInsightsController',
'SnapInterfaceController',
'MultichainRoutingService',
'ExecutionService',
'SnapRegistryController',
];
const MessengerCallParametersStruct = (0, superstruct_1.object)({
action: (0, utils_1.definePattern)('MessengerAction', /^.+:.+$/u),
params: (0, superstruct_1.array)(utils_1.JsonStruct),
});
/**
* Handler for the `snap_messengerCall` method.
*
* @internal
*/
exports.messengerCallHandler = {
implementation: getMessengerCallImplementation,
hookNames,
actionNames: ['SnapController:getSnap', 'PermissionController:getPermission'],
};
/**
* The `snap_messengerCall` method implementation. This method is used to dispatch
* an action via the messenger. It is only available to preinstalled Snaps.
*
* @param request - The JSON-RPC request object.
* @param response - The JSON-RPC response object.
* @param _next - The `json-rpc-engine` "next" callback. Not used by this
* function.
* @param end - The `json-rpc-engine` "end" callback.
* @param hooks - The RPC method hooks.
* @param hooks.getMessenger - The hook function to create a custom messenger for the Snap.
* @param messenger - The messenger used to call controller actions.
* @returns Nothing.
*/
async function getMessengerCallImplementation(request, response, _next, end, { getMessenger }, messenger) {
const snap = messenger.call('SnapController:getSnap', request.origin);
const permission = messenger.call('PermissionController:getPermission', request.origin, endowments_1.SnapEndowments.Messenger);
if (!snap?.preinstalled || !permission) {
return end(rpc_errors_1.rpcErrors.methodNotFound());
}
const actions = (0, messenger_1.getMessengerCaveatActions)(permission);
const snapMessenger = getMessenger({ actions });
const { params } = request;
try {
const { action, params: actionParams } = getValidatedParams(params);
if (BLOCKED_MESSENGER_CLIENTS.some((namespace) => action.startsWith(namespace))) {
return end(rpc_errors_1.rpcErrors.invalidParams({
message: `Access to the following messenger clients are disallowed in Snaps: ${BLOCKED_MESSENGER_CLIENTS.join(', ')}.`,
}));
}
response.result = await snapMessenger.call(action, ...actionParams);
}
catch (error) {
return end(error);
}
return end();
}
/**
* Validate the parameters for the `snap_messengerCall` method.
*
* @param params - Parameters to validate.
* @returns Validated parameters.
* @throws Throws RPC error if validation fails.
*/
function getValidatedParams(params) {
try {
return (0, superstruct_1.create)(params, MessengerCallParametersStruct);
}
catch (error) {
if (error instanceof superstruct_1.StructError) {
throw rpc_errors_1.rpcErrors.invalidParams({
message: `Invalid params: ${error.message}.`,
});
}
/* istanbul ignore next */
throw rpc_errors_1.rpcErrors.internal();
}
}
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