In 2015, Microsoft announced its intent to bring OpenSSH, the widely used implementation of the secure shell (ssh) protocol used for remote system access and administration throughout the UNIX world, natively to Windows. Without too many people noticing, it turns out that the company has now done this. The Windows 10 Fall Creators Update adds a couple of optional features, with both client and server now available for installation (via Serve The Home).

Add the feature from the Optional Features settings page and, well... I think it works, but I'm not entirely sure because I can't make it work. It can't use my RSA key—Microsoft's issues list on GitHub says that only ed25519 keys are supported at present—but my ed25519 key isn't working either. I have seen people successfully use it with password authentication, but I don't have a password-authenticated server to actually test with right now. Both my keys work fine from Windows Subsystem for Linux ssh, so I'm confident that they're fine; the native Win32 program just doesn't like them for reasons that aren't at all obvious at this time.

Update: I rebooted both ends for unrelated reasons, and now the ed25519 key is working. I have no idea what changed.

I'm sure that eventually the wrinkles will be fixed. This is a beta and it's not installed by default, so hiccups aren't a huge surprise. But it's another little sign that Microsoft is continuing to embrace the wider world beyond Windows. I don't expect that ssh will become the main tool for administration of Windows machines any time soon—though with the ssh server and PowerShell, even that isn't impossible to imagine—but when this works, it's going to make connecting to and using other systems from Windows that bit more convenient.

For now, though, I'm going to stick with PuTTY, because PuTTY actually works.