Only allow http and https

[TarLaboratories]

What

Only allow http and https in central monitor

[pau101]

Though this is an improvement, I would be weary of the GTCEu.isClientSide() case, this is true for a LAN host. Also, I would impose a restriction on the amount of bytes read from the stream. Here is possible patch how I may approach it, moving all logic to the client with some additional enhancements.

[TarLaboratories]

It is true for a LAN host, but if you've got someone on your LAN who wants to hack you I'm pretty sure you've got bigger problems than this :)
I really don't want to move image requesting to client-side due to certain image hosts (imgur) being banned in certain regions (UK), and, as a consequence, some players not being able to actually see said images.

[pau101]

Well the thing with LAN is you have no control over who can join without additional mods. As well, LAN is used with mods like e4mc to open it up to the internet. The impact is severe enough, it at least would need a significant user warning to have that feature enabled. A LAN network may not be something you have control over in shared living spaces, though less likely to be a target I would not imagine a user to be comfortable knowing of that possibility.

For still running on server side, that can be alright if fully safe guarded with an option to disable. As well as some additional notices about importance of those allowed domains to prevent any local network web servers being inadvertently accessible.

[TechLord22]

Can this use regular equals()?