# ICFS -- Interactively Controlled File System

## Motivation

Traditional access control mechanisms in operating systems allow the same level of access to all processes running on behalf of the same user. This typically enables malicious processes to read and/or modify all data accessible to the user running a vulnerable application. It can be dealt using various mandatory access control mechanisms, but these are often complicated to configure and are rarely used in common user oriented scenarios. This thesis focuses on design and implementation of a file system layer which delegates the decision to allow or deny access to a file system object by a specific process to the user.

## Goals

- Analyze the problem and design a solution
- Implement the solution using the FUSE framework
- Test the solution and demonstrate its benefits

## Building

- Install dependencies
  - libfuse3
    - Debian: `sudo apt install fuse3 libfuse3-dev`
  - Build tools
    - Debian: `sudo apt install gcc make pkg-config`
- Build using `make`:
  - In the project directory: `make`
  - Add `DEBUG=1` to show more compiler warnings.
  - Add `TEST=1` to also test the program.
  - Add `DIALOGUE=0` to not compile the dialogue program.
- Resulting binaries should appear in the `build` directory.

## Installation

- `make install`
- Uninstall with `make uninstall`

## Usage

```
icfs <FUSE arguments> [target directory] [path to permanent permission database]
```

The filesystem will be mounted over the target directory, and ask user permission every time a file in that directory is opened. We highly recommend adding `-o default_permissions` to increase performance and add an additional security layer. If you have installed icfs along with `/etc/icfs` folder, you can create your permanent permission databases in this folder (you might want to do this, if your home folder does not have the "execute" permission for other users).

### Development build

Execute this command in the root directory of this project:

```
env PATH="$(realpath ./build):$PATH" build/icfs <FUSE arguments> [target directory] [path to permanent permission database]
```

The `env PATH="$(realpath ./build):$PATH"` adds the access dialogue program to PATH, allowing ICFS to call it seamlessly.

## Docs

- [Initial idea and motivation](./docs/bc-thesis-idea.md)
- [Some identified issues](./docs/bc-thesis-problems.md)
- [Formal specification](./docs/bc-thesis-specs.md)

## Credit

_Student:_ Fedir Kovalov

_Supervisor:_ RNDr. Jaroslav Janáček, PhD.