guard_google: Guard for Authenticating with the Google OpenID Connect...

In fireproof: Authentication and Authorization for 'fiery' Servers

Guard for Authenticating with the Google OpenID Connect server

Description

This guard requests you to log in with google and authenticates you through their service. Your server must be registered and have a valid client ID and client secret for this to work. Read more about registering an application at https://developers.google.com/identity/protocols/oauth2. If you want to limit access to only select users you should make sure to provide a validate function that checks the userinfo against a whitelist.

Usage

guard_google(
  redirect_url,
  client_id,
  client_secret,
  oauth_scopes = "profile",
  service_params = list(access_type = "offline", include_granted_scopes = "true"),
  ...,
  name = "google"
)

Arguments

redirect_url	The URL the authorization server should redirect to following a successful authorization. Must be equivalent to one provided when registering your application
client_id	The ID issued by the authorization server when registering your application
client_secret	The secret issued by the authorization server when registering your application. Do NOT store this in plain text
oauth_scopes	Optional character vector of scopes to request the user to grant you during authorization. These will not influence the scopes granted by the validate function and fireproof scoping. If named, the names are taken as scopes and the elements as descriptions of the scopes, e.g. given a scope, read, it can either be provided as c("read") or c(read = "Grant read access")
service_params	A named list of additional query params to add to the url when constructing the authorization url in the "authorization_code" grant type
...	Arguments passed on to guard_oidc request_user_info Logical. Should the userinfo endpoint be followed to add information about the user not present in the JWT token. Setting this to TRUE will add an additional API call to your authentication flow but potentially provide richer information about the user. grant_type The type of authorization scheme to use, either "authorization_code" or "password" validate Function to validate the user once logged in. It will be called with a single argument info, which gets the information of the user as provided by the user_info function in the. By default it returns TRUE on everything meaning that anyone who can log in with the provider will be accepted, but you can provide a different function to e.g. restrict access to certain user names etc. If the function returns a character vector it is considered to be authenticated and the return value will be understood as scopes the user is granted. redirect_path The path that should capture redirects after successful authorization. By default this is derived from redirect_url by removing the domain part of the url, but if for some reason this doesn't yields the correct result for your server setup you can overwrite it here. on_auth A function which will handle the result of a successful authorization. It will be called with four arguments: request, response, session_state, and server. The first contains the current request being responded to, the second is the response being send back, the third is a list recording the state of the original request which initiated the authorization (containing method, url, headers, and body fields with information from the original request). By default it will use replay_request to internally replay the original request and send back the response.
name	The name of the guard

Value

A GuardOIDC object

User information

guard_google() automatically adds user information according to the description in guard_oidc(). It sets the provider field to "google".

References

Documentation for Googles OpenID Connect flow

Examples

google <- guard_google(
  redirect_url = "https://example.com/auth",
  client_id = "MY_APP_ID",
  client_secret = "SUCHASECRET"
)

# Add it to a fireproof plugin
fp <- Fireproof$new()
fp$add_guard(google, "google_auth")

# Use it in an endpoint
fp$add_auth("get", "/*", google_auth)

fireproof documentation built on Dec. 17, 2025, 5:09 p.m.