Prepare a OAuth 2.0 authorization call and build an authorization URL

Prepares an OAuth 2.0 authorization request and returns the browser redirect URL. It generates the needed state, PKCE, and nonce values, stores the one-time callback data, and builds the final authorization URL.

Usage

prepare_call(oauth_client, browser_token)

Arguments

oauth_client: An OAuthClient object.
browser_token: Browser-bound token used to tie the login attempt to the current browser session.

Value

A length-1 string containing the authorization URL to send the user to. When PAR is used, the returned string also carries shinyOAuth.par_request_uri, shinyOAuth.par_expires_in, and shinyOAuth.par_expires_at attributes so callers can tell when the pushed authorization request should be regenerated.

Examples

# Please note: `prepare_call()` & `handle_callback()` are typically
# not called by users of this package directly, but are called
# internally by `oauth_module_server()`. These functions are exported
# nonetheless for advanced use cases. Most users will not need to
# call these functions directly

# Below code shows generic usage of `prepare_call()` and `handle_callback()`
# (code is not run because it would require user interaction)
if (interactive()) {
  # Define client
  client <- oauth_client(
    provider = oauth_provider_github(),
    client_id = Sys.getenv("GITHUB_OAUTH_CLIENT_ID"),
    client_secret = Sys.getenv("GITHUB_OAUTH_CLIENT_SECRET"),
    redirect_uri = "http://127.0.0.1:8100"
  )

  # Get authorization URL and and store state in client's state store
  # `<browser_token>` is a token that identifies the browser session
  #  and would typically be stored in a browser cookie
  #  (`oauth_module_server()` handles this typically)
  authorization_url <- prepare_call(client, "<browser_token>")

  # Redirect user to authorization URL; retrieve code & payload from query;
  # read also `<browser_token>` from browser cookie
  # (`oauth_module_server()` handles this typically)
  code <- "..."
  payload <- "..."
  browser_token <- "..."

  # Handle callback, exchanging code for token and validating state
  # (`oauth_module_server()` handles this typically)
  token <- handle_callback(client, code, payload, browser_token)
}