This is an old topic and feature request is active, and I see you have a release on MyGet.
I’m also coming into this requirement. I’ll checkout the MyGet option later.
Main reason for the reply is I wanted to make you aware of the aspnet-contrib/AspNet.Security.OAuth.Providers project. Not sure how easily it’ll be able to integrate into ServiceStack, but they already have a lot of providers integrated for .NET Core.
Including the ones provided by Microsoft (e.g. Google), they also have
AspNet.Security.OAuth.Amazon
AspNet.Security.OAuth.ArcGIS
AspNet.Security.OAuth.Asana
AspNet.Security.OAuth.Autodesk
AspNet.Security.OAuth.Automatic
AspNet.Security.OAuth.BattleNet
AspNet.Security.OAuth.Beam
AspNet.Security.OAuth.Bitbucket
AspNet.Security.OAuth.Buffer
AspNet.Security.OAuth.CiscoSpark
AspNet.Security.OAuth.DeviantArt
AspNet.Security.OAuth.Discord
AspNet.Security.OAuth.Dropbox
AspNet.Security.OAuth.EVEOnline
AspNet.Security.OAuth.Fitbit
AspNet.Security.OAuth.Foursquare
AspNet.Security.OAuth.GitHub
AspNet.Security.OAuth.Gitter
AspNet.Security.OAuth.HealthGraph
AspNet.Security.OAuth.Imgur
AspNet.Security.OAuth.Instagram
AspNet.Security.OAuth.LinkedIn
AspNet.Security.OAuth.MailChimp
AspNet.Security.OAuth.Myob
AspNet.Security.OAuth.Onshape
AspNet.Security.OAuth.Patreon
AspNet.Security.OAuth.Paypal
AspNet.Security.OAuth.QQ
AspNet.Security.OAuth.Reddit
AspNet.Security.OAuth.Salesforce
AspNet.Security.OAuth.Slack
AspNet.Security.OAuth.SoundCloud
AspNet.Security.OAuth.Spotify
AspNet.Security.OAuth.StackExchange
AspNet.Security.OAuth.Strava
AspNet.Security.OAuth.Twitch
AspNet.Security.OAuth.Untappd
AspNet.Security.OAuth.Vimeo
AspNet.Security.OAuth.VisualStudio
AspNet.Security.OAuth.Vkontakte
AspNet.Security.OAuth.Weibo
AspNet.Security.OAuth.Weixin
AspNet.Security.OAuth.WordPress
AspNet.Security.OAuth.Yahoo
AspNet.Security.OAuth.Yammer
AspNet.Security.OAuth.Yandex