ipfs-companion clears local storage when using local gateway

[xuhcc]

Describe the bug

If I configure ipfs-companion to use local subdomain gateway it somehow clears local storage every time the page is loaded via gateway, and not only at ipfs.localhost origin, but on all localhost origins. This does not happen when I use remote path-based gateway.

To Reproduce
Steps to reproduce the behavior:

1. Open local page (e.g. http://localhost:1234) and add something to local storage.
2. Open new tab and load something via local IPFS gateway, for example http://blog.ipfs.io.ipns.localhost:8001/
3. Local storage at http://blog.ipfs.io.ipns.localhost:8001/ is cleared
4. Local storage at http://localhost:1234 also cleared

Expected behavior

Local storage must not be cleared anywhere.

Desktop:

• OS: Linux
• Browser: Firefox 84
• IPFS companion: 2.17.3

[lidel]

Thank you for reporting this @xuhcc, nice catch!

I suspect this might be because we use path-based router which then returns a redirect to the proper subdomain.
It is the same as redirect as when opening https://dweb.link/ipns/en.wikipedia-on-ipfs.org and ending up at https://en-wikipedia--on--ipfs-org.ipns.dweb.link

The caveat is that the redirect is returned with Clear-Site-Data: "cookies", "storage" HTTP header which was added to go-ipfs as precaution in early days of subdomain gateways. This header should be ignored by browsers on redirects, but it seems that Firefox acts on it (I confirmed that Brave does not clear cookies).

I believe we should remove Clear-Site-Data from redirect responses:

• subdomain gateways ended up being self-contained. Once a gateway domain is defined in config, it is impossible to load websites from paths, we always return either a redirect or an error
• Clear-Site-Data support across vendors is buggy and that is not just Firefox: Chromium been ignoring related bug for three years: https://bugs.chromium.org/p/chromium/issues/detail?id=898503)

Will prepare upstream fix shortly and will try to include it in go-ipfs 0.8.0.
Until that happens, a workaround is to use Brave.

[xuhcc]

@lidel Has the fix been included in go-ipfs 0.8.0?

[lidel]

@xuhcc no, it is scheduled for 0.9.0: ipfs/kubo#7890