Only on desktop. Mobile has this sorted. Programs have access to their own files unrestricted, and then can access the shared file space only through the users specifically selecting them.

▲

josephg 2 hours ago | parent [-]

I think there's 2 kinds of systems we're talking about here:

1. Capabilities given to a program by the user. Eg, "This program wants to access your contacts. Allow / deny". But everything within a program might still have undifferentiated access. This requires support from the operating system to restrict what a program can do. This exists today in iOS and Android.

2. Capabilities within a program. So, if I call a function in a 3rd party library with the signature add(int, int), it can't access the filesystem or open network connections or access any data thats not in its argument list. Enforcing this would require support from the programming language, not the operating system. I don't know of any programming languages today which do this. C and Rust both fail here, as any function in the program can access the memory space of the entire program and make arbitrary syscalls.

Application level permissions are a good start. But we need the second kind of fine-grained capabilities to protect us from malicious packages in npm, pip and cargo.

	▲	ratmice 40 minutes ago \| parent [-]
		I would also say there is a 3rd class, which are distributed capabilities. When you look at a mobile program such as the GadgetBridge which is synchronizing data between a mobile device and a watch, and number of permissions it requires like contacts, bluetooth pairing, notifications, yadda yadda the list goes on. Systems like E-Lang wouldn't bundle all these up into a single application. Your watch would have some capabilities, and those would interact directly with capabilities on the phone. I feel like if you want to look at our current popular mobile OS's as capability systems the capabilities are pretty coarse grained. One thing I would add about compilers, npm, pip, cargo. Is that compilers are transformational programs, they really only need read and write access to a finite set of input, and output. In that sense, even capabilities are overkill because honestly they only need the bare minimum of IO, a batch processing system could do better than our mainstream OS security model.