yesod-auth-oauth2/src/Yesod/Auth/OAuth2/Google.hs
2021-03-08 09:40:26 -05:00

86 lines
2.7 KiB
Haskell

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE QuasiQuotes #-}
-- |
--
-- OAuth2 plugin for http://www.google.com
--
-- * Authenticates against Google
-- * Uses Google user id as credentials identifier
--
-- If you were previously relying on email as the creds identifier, you can
-- still do that (and more) by overriding it in the creds returned by the plugin
-- with any value read out of the new @userResponse@ key in @'credsExtra'@.
--
-- For example:
--
-- > data User = User { userEmail :: Text }
-- >
-- > instance FromJSON User where -- you know...
-- >
-- > authenticate creds = do
-- > -- 'getUserResponseJSON' provided by "Yesod.Auth.OAuth" module
-- > let Right email = userEmail <$> getUserResponseJSON creds
-- > updatedCreds = creds { credsIdent = email }
-- >
-- > -- continue normally with updatedCreds
--
module Yesod.Auth.OAuth2.Google
( oauth2Google
, oauth2GoogleWidget
, oauth2GoogleScoped
, oauth2GoogleScopedWidget
)
where
import Yesod.Auth.OAuth2.Prelude
import Yesod.Core (WidgetFor, whamlet)
newtype User = User Text
instance FromJSON User where
parseJSON =
withObject "User" $ \o -> User
-- Required for data backwards-compatibility
<$> (("google-uid:" <>) <$> o .: "sub")
pluginName :: Text
pluginName = "google"
defaultScopes :: [Text]
defaultScopes = ["openid", "email"]
oauth2Google :: YesodAuth m => Text -> Text -> AuthPlugin m
oauth2Google = oauth2GoogleScoped defaultScopes
oauth2GoogleWidget :: YesodAuth m => WidgetFor m () -> Text -> Text -> AuthPlugin m
oauth2GoogleWidget widget = oauth2GoogleScopedWidget widget defaultScopes
oauth2GoogleScoped :: YesodAuth m => [Text] -> Text -> Text -> AuthPlugin m
oauth2GoogleScoped = oauth2GoogleScopedWidget [whamlet|Login via #{pluginName}|]
oauth2GoogleScopedWidget :: YesodAuth m => WidgetFor m () -> [Text] -> Text -> Text -> AuthPlugin m
oauth2GoogleScopedWidget widget scopes clientId clientSecret =
authOAuth2Widget widget pluginName oauth2 $ \manager token -> do
(User userId, userResponse) <- authGetProfile
pluginName
manager
token
"https://www.googleapis.com/oauth2/v3/userinfo"
pure Creds
{ credsPlugin = pluginName
, credsIdent = userId
, credsExtra = setExtra token userResponse
}
where
oauth2 = OAuth2
{ oauthClientId = clientId
, oauthClientSecret = Just clientSecret
, oauthOAuthorizeEndpoint =
"https://accounts.google.com/o/oauth2/auth"
`withQuery` [scopeParam " " scopes]
, oauthAccessTokenEndpoint =
"https://www.googleapis.com/oauth2/v3/token"
, oauthCallback = Nothing
}