SwiftNIO SSH Implementation
Article Summary
Cory Benfield from Apple's Cloud Services team just open-sourced SwiftNIO SSH, bringing programmatic SSH capabilities to Swift. Think libssh2, not openssh: this isn't a ready-made client, it's the building blocks for something more interesting.
SwiftNIO SSH is a new library that lets Swift developers build custom SSH clients and servers programmatically. Instead of shelling out to command-line SSH, you can now handle SSH connections directly in your Swift code, opening up creative possibilities beyond traditional remote shell access.
Key Takeaways
- Supports SSHv2 with modern crypto: Ed25519, ECDSA, AES-GCM, x25519 key exchange
- Uses child channel abstraction to handle SSH's multiplexed protocol elegantly
- Enables creative SSH uses like embedded Python interpreters or chat servers
- Handles both direct and reverse TCP port forwarding programmatically
- Fully async authentication delegates support disk reads without blocking
Critical Insight
Swift developers can now build custom SSH implementations directly into their services without spawning subprocesses or wrapping C libraries.
