iPurity

iPurity is a simple NSFW (Not Safe For Work) detector for iOS devices.

It utilizes AFC (Apple File Conduit) to list and open each media file and OpenCV to detect nsfw images.

Note: Tested only on Apple Silicon Mac

Why did I make this?

• The program was created because one of my younger siblings accidentally encountered NSFW content.
• There is often no time to manually check all images on their phone before passing it to a younger sibling.
• This program aims to assist in identifying potentially inappropriate content.

Disclaimer

• There may be many false negatives; however, it can help reduce the dataset to scan by approximately 90-95%.

Prerequisites

• libimobiledevice
• OpenCV
• Make

Installation

Option 1: Homebrew (Custom Tap)

You can install iPurity from our custom Homebrew tap:

brew tap Agent-Hellboy/homebrew-agent-hellboy-formula
brew install agent-hellboy/homebrew-agent-hellboy-formula/ipurity

Option 2: Build from Source

./configure
mkdir build
cd build
cmake ..
cmake --build .

Installation

sudo cmake --build . --target install

Usage

./ipurity <threshold> //By default <threshold> is set to 0.6

Development

Build with -fsanitize=thread option

export CFLAGS="-fsanitize=thread"
export LDFLAGS="-fsanitize=thread"
cmake -DCMAKE_CXX_FLAGS="-fsanitize=thread" -DCMAKE_EXE_LINKER_FLAGS="-fsanitize=thread" ..

Architecture Overview

                    +----------------+
                    |     main()     |
                    +----------------+
                            │
                            ▼
            +-------------------------------+
            | Create Device & AFC Client Pool |
            +-------------------------------+
                            │
                            ▼
                    +-----------------+
                    | scan_directory()|
                    +-----------------+
                            │
         ┌──────────────────┼──────────────────┐
         │                                     │
         ▼                                     ▼
[Directory Entry]                      [File Entry]
(recursive call)               (launch async task for file)
                                         │
                                         ▼
                                +---------------------------+
                                | process_image_file()      |
                                +---------------------------+
                                         │
                                         ▼
                           +-------------------------------+
                           |  [Thread X]                   |
                           |  1. Acquire AFC client from   |
                           |     pool                      |
                           |  2. download_file()           |
                           |  3. naiveNSFWCheck()          |
                           |  4. Release client back to pool|
                           |  5. Update ScanStats (mutex)  |
                           +-------------------------------+

License

iPurity is released under the MIT License.