InvalidSignatureException on redirect fetch in CF Worker about aws4fetch

[Manouchehri]

Closing as this is not a bug with aws4fetch, only wanted to document this issue and solution for others.

[mhart]

Thanks for documenting this @Manouchehri – I must admit I've never encountered a 3xx using AWS signing before, so hadn't really thought about fetch's default behavior here.

I feel like, as you say, aws4fetch probably shouldn't do anything special here. If it tried to detect whether the user had the redirect setting unset or follow, but then behind the scenes set it to manual and intercepted, signed and made the new request – it might sound like that's the right thing to do – but aws4fetch has no idea if the URL being redirected to needs to be signed or not, even if it happened to be on the same host as the original request. So I think it's less magic to just leave it as is, and let the user implement that behavior if they want.

I'll add a note to the documentation about this when I get the chance, thanks again.