32aeec9630
This PR hot-fixes permission escapes in dynamic imports, workers and runtime compiler APIs. "permissions" parameter was added to public APIs of SourceFileFetcher and appropriate permission checks are performed during loading of local and remote files.
2.3 KiB
Workers
Deno supports
Web Worker API.
Workers can be used to run code on multiple threads. Each instance of Worker
is run on a separate thread, dedicated only to that worker.
Currently Deno supports only module type workers; thus it's essential to pass
type: "module" option when creating new worker:
// Good
new Worker("./worker.js", { type: "module" });
// Bad
new Worker("./worker.js");
new Worker("./worker.js", { type: "classic" });
Permissions
Creating a new Worker instance is similar to a dynamic import; therefore Deno
requires appropriate permission for this action.
For workers using local modules; --allow-read permission is required:
// main.ts
new Worker("./worker.ts", { type: "module" });
// worker.ts
console.log("hello world");
self.close();
$ deno run main.ts
error: Uncaught PermissionDenied: read access to "./worker.ts", run again with the --allow-read flag
$ deno run --allow-read main.ts
hello world
For workers using remote modules; --allow-read permission is required:
// main.ts
new Worker("https://example.com/worker.ts", { type: "module" });
// worker.ts
console.log("hello world");
self.close();
$ deno run main.ts
error: Uncaught PermissionDenied: net access to "https://example.com/worker.ts", run again with the --allow-net flag
$ deno run --allow-net main.ts
hello world
Using Deno in worker
This is an unstable Deno feature. Learn more about unstable features.
By default Deno namespace is not available in worker scope.
To add Deno namespace pass deno: true option when creating new worker:
// main.js
const worker = new Worker("./worker.js", { type: "module", deno: true });
worker.postMessage({ filename: "./log.txt" });
// worker.js
self.onmessage = async (e) => {
const { filename } = e.data;
const text = await Deno.readTextFile(filename);
console.log(text);
self.close();
};
// log.txt
hello world
$ deno run --allow-read --unstable main.js
hello world
When Deno namespace is available in worker scope; the worker inherits parent
process permissions (the ones specified using --allow-* flags).
We intend to make permissions configurable for workers.