So, what do you suggest? The hint "does the network require authentication?" is already a wild guess as this can happen for temporary down servers (e.g. "Down for maintenance"), 'longtime down' servers (e.g. domain grabber got the domain), the network you are on requires you to authenticate (first time, again, after X minutes, for specific domains), the network has a pre-processing proxy to reduce traffic/enforce restrictions/parental control, the archive software really produced invalid files or you are under attack …
The sentence is easily 400 characters long and hasn't mentioned a single "solution" yet even though for all different things need (not) to be done. If anyone can provide a better hint than the current which will fit on one line feel free tell us, but I don't expect that we can do anything reasonable to detect which one of the various possible problems that could be. (It might first sound like we could detect "normal" vs. "restricted" archives as it seems to happen here, but APT really has no idea what the difference is, further more these could be on different mirrors, used via a proxy… so while this is "easy" (really?) to detect for a human, its close to impossible in code) I have some hope for "511 Network Authentication Required" ( https://tools.ietf.org/html/rfc6585#section-6 ), but I haven't seen it implemented so far [APT has no specific support for it so far, but works as intended by default as any client should do]. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1206824 Title: bogus network proxies might cause: Clearsigned file isn't valid, got 'NODATA' (does the network require authentication?) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apt/+bug/1206824/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
