This demonstrates a difference in behaviour between chrome and firefox/safari
To try it out visit https://credentialless.peergos.com/ or run it on localhost.
java Server.java
Navigate to: localhost:10000
The purpose is to have the inner iframe on a subdomain subdomain.domain.com to provide a secure sandbox to load arbitrary html.
The file Server.java provides a minimal web server that sets additional response headers (ie COOP, COEP, CORP) and is directly executable without compilation.
main.js constructs an iframe and adds it to index.html.
The .src is set to /apps/sandbox/sandbox.html which contains the inner iframe.
The associated file sandbox.js loads a service worker to intercept requests.
If I check crossOriginIsolated inside the sandboxed iframe it is set to FALSE In Safari and firefox it is set to TRUE.
The fact that it is FALSE means I cannot host multi-threaded WASM code in the sandbox as SharedArrayBuffer is only available if crossOriginIsolated=TRUE
Alternative method to demonstrate issue
- Create an account on peergos-demo.net
- upload a minimal .html file with code:
<!DOCTYPE html>
<html lang="en">
<body>
<h2>Hello World!</h2>
<label id="inside-isolatedIFrame"></label>
</body>
<script>
window.onload = function() {
document.getElementById("inside-isolatedIFrame").innerText = "Inside - Cross Origin Isolated: " + crossOriginIsolated;
}
</script>
</html>
- view the html file in the in-built html viewer (view action available from right-click menu)