NewCredentials parses a credential string in the format `id:string` and returns a Credentials suitable for OAuth Provider configuration.

NewFacebookProvider returns a AuthN integration for Facebook OAuth.

NewGitHubProvider returns a AuthN integration for GitHub OAuth.

NewGoogleProvider returns a AuthN integration for Google OAuth.

NewProvider returns a properly configured Provider.

NewTestProvider returns a special Provider for tests.

Credentials is a configuration struct for OAuth Providers.

Provider is a struct wrapping the necessary bits to integrate an OAuth2 provider with AuthN.

UserInfo is the minimum necessary needed from an OAuth Provider to connect with AuthN accounts.

UserInfoFetcher is the function signature for fetching UserInfo from a Provider.