SoftU2FTool is a software U2F authenticator for OS X. It emulates a hardware U2F HID device using SoftU2F and performs cryptographic operations using the OS X Keychain. This tool works with Google Chrome and Opera's built-in U2F implementations as well as with the U2F extensions for OS X Safari and Firefox.

You must have Xcode Command Line Tools installed to build this project.

# Install Commaned Line Tools
xcode-select --install

# Build softu2f.kext and SoftU2FTool.app.
script/build

I'm waiting on Apple to get a certificate for signing kernel extension. In the meantime, you'll have to disable System Integrity Protection before trying to load softu2f.kext and run SoftU2FTool.app.

script/run

With the app running, you'll receive notifications when sites try to register or authenticate with U2F.

Every website using U2F has an app-ID. For example, the app-ID of Yubico's U2F demo page is https://demo.yubico.com. When the low-level U2F authenticator receives a request to register/authenticate a website, it doesn't receive the friendly app-ID string. Instead, it receives a SHA256 digest of the app-ID. To be able to show a helpful alert message when a website is trying to register/authenticate, a list of app-ID digests is maintained in this repository. You can find the list here. If your companies app-ID is missing from this list, open a pull request to add it.