Directories permissions on Windows

[darosior]

revaultd is creating a directory (the "datadir") and some files (the database, the UNIX domain socket for RPC) on the host OS. We want to setup some basic OS permissions on these files (why would another user get allowed to modify our database, or use our RPC socket?). These permissions are set up at creation time in different places:

• https://github.com/re-vault/revaultd/blob/68295908962abeb5b2e85ad6a4d3218273f27333/src/daemon/revaultd.rs#L205-L220
• https://github.com/re-vault/revaultd/blob/68295908962abeb5b2e85ad6a4d3218273f27333/src/daemon/database/actions.rs#L30-L49
• https://github.com/re-vault/revaultd/blob/68295908962abeb5b2e85ad6a4d3218273f27333/src/daemon/jsonrpc/mod.rs#L315-L328

However, they are only currently setup for UNIX systems, and Windows is special-cased to setup no particular restrictions. We need to setup some permissions also on Windows, but first we need to figure out how :)

Some guidance on this issue:

• It seems that the equivalent of permissions under Windows is to use ACLs. Maybe the stdlib has some way of abstracting it. Please don't introduce new dependencies just for this :).
• To decode the UNIX permissions set in the links above, we want rw only for the owner of the file for the database and the RPC and rwx (still only for the owner) for the data directory.

[darosior]

Interestingly the Win part of libc has chmod https://github.com/rust-lang/libc/blob/36a6a8e254db89cd31d178b4ba102055ceabf9a8/src/windows/mod.rs#L376-L379

[vaibhavgarg237]

• I was navigating through different rust and MS official docs and looks like we can only set a file to readonly using the Rust stdlib https://doc.rust-lang.org/std/fs/fn.set_permissions.html ( Only read only permissions )

• Below links seems interesting but I was not able to find any fruitful results, but will try to explore more...
  _chmod calls in windows
  MS Doc -> https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/chmod-wchmod?view=msvc-160
  libc Rust -> https://github.com/rust-lang/libc/blob/36a6a8e254db89cd31d178b4ba102055ceabf9a8/src/windows/mod.rs#L376-L379

• Rust bindings to windows permissions API -> https://docs.rs/windows-permissions/0.2.4/windows_permissions/ ( No conclusion yet, but seems interesting. Looks like this can only know, what permissions are already enforced )

• But irony is Here in node, chmod doesn't works on windows...