# OpenDrop: an open reimplementation of Apple AirDrop

> Python command-line reimplementation of Apple's AirDrop protocol from SEEMOO Lab's reverse-engineering research. It finds receivers via _airdrop._tcp DNS-SD, sends binary-plist /Discover and /Ask requests over HTTPS and uploads gzip-compressed CPIO archives to exchange files with iOS and macOS. It is not affiliated with Apple.

- Type: Case study
- Targets: Protocol
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-10-19
- Added to the catalog: 2026-10-30
- Original resource: <https://github.com/seemoo-lab/opendrop>
- Primary source: <https://github.com/seemoo-lab/opendrop/blob/11fe7ba7861093b302bc0637e8cb10adf2d29337/README.md>
- Catalog page: <https://awesomerea.org/resources/opendrop-airdrop-reimplementation-case/>
- Record JSON: <https://awesomerea.org/resources/opendrop-airdrop-reimplementation-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/opendrop-airdrop-reimplementation-case/index.md)

## Requirements & limits

- README calls OpenDrop experimental output of the Open Wireless Link reverse-engineering effort that lacks some AirDrop features and may break with future AirDrop versions, and says Apple neither affiliates with nor endorses it. The latest release is 0.13.0 (PyPI, 2021-04-29); the reviewed master commit of 2026-08-17 adds only a citation file and link edits since.
- AirDrop runs only over Apple Wireless Direct Link, so OpenDrop is supported on macOS or on Linux with an open AWDL implementation such as SEEMOO's OWL; the default interface is awdl0. It needs Python 3.6+ (classifiers list 3.6–3.9), a current libarchive (Homebrew's on macOS), the openssl command and the packages in setup.py, including zeroconf and libarchive-c.
- By default it creates its own self-signed key and certificate. Receivers in the default contacts-only mode need AirDrop keys, a certificate and an Apple ID validation record from the user's own Mac, which README says come from a separate SEEMOO extractor; the repository ships only Apple's public root CA certificate.
- README lists known gaps: no Bluetooth Low Energy trigger, so Apple receivers may stay undiscovered; no peer authentication (neither TLS certificate chains nor validation records are checked) and automatic acceptance of every incoming file; and one file per transfer, with links sent but not received. CI runs black, flake8 and pytest on Python 3.6–3.9; its two tests only start the browser and server on loopback.
- GPL-3.0. README points to the authors' USENIX Security 2019 AWDL paper and 2021 PrivateDrop paper for protocol details; AirDrop and AWDL remain Apple's protocols.

## Primary sources

1. <https://github.com/seemoo-lab/opendrop/blob/11fe7ba7861093b302bc0637e8cb10adf2d29337/README.md>
2. <https://github.com/seemoo-lab/opendrop/blob/11fe7ba7861093b302bc0637e8cb10adf2d29337/setup.py>
3. <https://github.com/seemoo-lab/opendrop/blob/11fe7ba7861093b302bc0637e8cb10adf2d29337/opendrop/config.py>
4. <https://github.com/seemoo-lab/opendrop/blob/11fe7ba7861093b302bc0637e8cb10adf2d29337/opendrop/client.py>
5. <https://github.com/seemoo-lab/opendrop/blob/11fe7ba7861093b302bc0637e8cb10adf2d29337/opendrop/server.py>
6. <https://github.com/seemoo-lab/opendrop/blob/11fe7ba7861093b302bc0637e8cb10adf2d29337/.github/workflows/testpackage.yml>
7. <https://github.com/seemoo-lab/opendrop/blob/11fe7ba7861093b302bc0637e8cb10adf2d29337/tests/test_server.py>
8. <https://github.com/seemoo-lab/opendrop/blob/11fe7ba7861093b302bc0637e8cb10adf2d29337/CITATION.cff>
9. <https://github.com/seemoo-lab/opendrop/blob/11fe7ba7861093b302bc0637e8cb10adf2d29337/LICENSE>
10. <https://pypi.org/project/opendrop/0.13.0/>
11. <https://www.usenix.org/conference/usenixsecurity19/presentation/stute>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.