Add initial support for a "pick your IdP" page (#9017)

During login, if there are multiple IdPs enabled, offer the user a choice of
IdPs.

1 files changed, 25 insertions, 0 deletions

diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml

index dd981609ac..c8ae46d1b3 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -1909,6 +1909,31 @@ sso:
     #
     # Synapse will look for the following templates in this directory:
     #
+    # * HTML page to prompt the user to choose an Identity Provider during
+    #   login: 'sso_login_idp_picker.html'.
+    #
+    #   This is only used if multiple SSO Identity Providers are configured.
+    #
+    #   When rendering, this template is given the following variables:
+    #     * redirect_url: the URL that the user will be redirected to after
+    #       login. Needs manual escaping (see
+    #       https://jinja.palletsprojects.com/en/2.11.x/templates/#html-escaping).
+    #
+    #     * server_name: the homeserver's name.
+    #
+    #     * providers: a list of available Identity Providers. Each element is
+    #       an object with the following attributes:
+    #         * idp_id: unique identifier for the IdP
+    #         * idp_name: user-facing name for the IdP
+    #
+    #   The rendered HTML page should contain a form which submits its results
+    #   back as a GET request, with the following query parameters:
+    #
+    #     * redirectUrl: the client redirect URI (ie, the `redirect_url` passed
+    #       to the template)
+    #
+    #     * idp: the 'idp_id' of the chosen IDP.
+    #
     # * HTML page for a confirmation step before redirecting back to the client
     #   with the login token: 'sso_redirect_confirm.html'.
     #