add readme

README.md

@@ -1 +1,41 @@
-# SoftU2F-Win
+Soft U2F is a software U2F authenticator for Windows. It emulates a hardware U2F HID device and performs cryptographic operations using the DPAPI. 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.
+
+We take the security of this project seriously. Report any security vulnerabilities to i#xiaoba.me
+
+## Installing
+
+Coming Soon.
+
+## Usage
+
+The app runs in the background. When a site loaded in a U2F-compatible browser attempts to register or authenticate with the software token, you'll see a notification asking you to accept or reject the request. You can experiment on [Yubico's U2F demo site](https://demo.yubico.com/u2f).
+
+### Registration
+
+### Authentication
+
+## Uninstalling
+
+Coming Soon.
+
+## Security considerations
+
+This is a port of https://github.com/github/SoftU2F.
+
+Instead of macOS Keychain, we store data using Windows DPAPI, which is designed by Microsoft Windows to store data data such as passwords, keys, and connection strings.
+
+For more infomation of DPAPI: https://docs.microsoft.com/en-us/dotnet/api/system.security.cryptography.protecteddata?view=netframework-4.8#remarks
+
+A [note](https://github.com/github/SoftU2F#security-considerations) from Github Team
+
+## Known app-IDs/facets
+
+Every website using U2F has an app-ID. For example, the app-ID of [Yubico's U2F demo page](https://demo.yubico.com/u2f) 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](https://github.com/ibigbug/SoftU2F-Win/blob/master/APDU/KnownFacets.cs). If your company's app-ID is missing from this list, open a pull request to add it.
+
+## Licensing
+
+This project is [Unlicensed](https://github.com/ibigbug/SoftU2F-Win/blob/master/LICENSE) yet.
+
+## Credits
+
+Lots of credits to the original work of [SoftU2F](https://github.com/github/SoftU2F) done by Github team.