From a986f86c827879f26abd574da6c7d12ac9578dd8 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Wed, 10 Jan 2024 17:16:49 +0000 Subject: [PATCH] Correctly handle OIDC config with no `client_secret` set (#16806) In previous versions of authlib using `client_secret_basic` without a `client_secret` would result in an invalid auth header. Since authlib 1.3 it throws an exception. The configuration may be accepted in by very lax servers, so we don't want to deny it outright. Instead, let's default the `client_auth_method` to `none`, which does the right thing. If the config specifies `client_auth_method` and no `client_secret` then that is going to be bogus and we should reject it --- changelog.d/16806.misc | 1 + synapse/config/oidc.py | 15 ++++++++++++++- 2 files changed, 15 insertions(+), 1 deletion(-) create mode 100644 changelog.d/16806.misc diff --git a/changelog.d/16806.misc b/changelog.d/16806.misc new file mode 100644 index 000000000..623338268 --- /dev/null +++ b/changelog.d/16806.misc @@ -0,0 +1 @@ +Reject OIDC config when `client_secret` isn't specified, but the auth method requires one. diff --git a/synapse/config/oidc.py b/synapse/config/oidc.py index 07ca16c94..8f9cdbddb 100644 --- a/synapse/config/oidc.py +++ b/synapse/config/oidc.py @@ -299,6 +299,19 @@ def _parse_oidc_config_dict( config_path + ("client_secret",), ) + # If no client secret is specified then the auth method must be None + client_auth_method = oidc_config.get("client_auth_method") + if client_secret is None and client_secret_jwt_key is None: + if client_auth_method is None: + client_auth_method = "none" + elif client_auth_method != "none": + raise ConfigError( + "No 'client_secret' is set in OIDC config, and 'client_auth_method' is not set to 'none'" + ) + + if client_auth_method is None: + client_auth_method = "client_secret_basic" + return OidcProviderConfig( idp_id=idp_id, idp_name=oidc_config.get("idp_name", "OIDC"), @@ -309,7 +322,7 @@ def _parse_oidc_config_dict( client_id=oidc_config["client_id"], client_secret=client_secret, client_secret_jwt_key=client_secret_jwt_key, - client_auth_method=oidc_config.get("client_auth_method", "client_secret_basic"), + client_auth_method=client_auth_method, pkce_method=oidc_config.get("pkce_method", "auto"), scopes=oidc_config.get("scopes", ["openid"]), authorization_endpoint=oidc_config.get("authorization_endpoint"),