Allow customizing IdP name and icon for SAML and CAS (#16094)

changelog.d/16094.feature

+Allow customising the IdP display name, icon, and brand for SAML and CAS providers (in addition to OIDC provider).

docs/usage/configuration/config_documentation.md

@@ -3025,6 +3025,16 @@ enable SAML login. You can either put your entire pysaml config inline using the
 option, or you can specify a path to a psyaml config file with the sub-option `config_path`.
 This setting has the following sub-options:
 
+* `idp_name`: A user-facing name for this identity provider, which is used to
+   offer the user a choice of login mechanisms.
+* `idp_icon`: An optional icon for this identity provider, which is presented
+   by clients and Synapse's own IdP picker page. If given, must be an
+   MXC URI of the format `mxc://<server-name>/<media-id>`. (An easy way to
+   obtain such an MXC URI is to upload an image to an (unencrypted) room
+   and then copy the "url" from the source of the event.)
+* `idp_brand`: An optional brand for this identity provider, allowing clients
+   to style the login flow according to the identity provider in question.
+   See the [spec](https://spec.matrix.org/latest/) for possible options here.
 * `sp_config`: the configuration for the pysaml2 Service Provider. See pysaml2 docs for format of config.
    Default values will be used for the `entityid` and `service` settings,
    so it is not normally necessary to specify them unless you need to
@@ -3176,7 +3186,7 @@ Options for each entry include:
 
 * `idp_icon`: An optional icon for this identity provider, which is presented
    by clients and Synapse's own IdP picker page. If given, must be an
-   MXC URI of the format mxc://<server-name>/<media-id>. (An easy way to
+   MXC URI of the format `mxc://<server-name>/<media-id>`. (An easy way to
    obtain such an MXC URI is to upload an image to an (unencrypted) room
    and then copy the "url" from the source of the event.)
 
@@ -3391,6 +3401,16 @@ Enable Central Authentication Service (CAS) for registration and login.
 Has the following sub-options:
 * `enabled`: Set this to true to enable authorization against a CAS server.
    Defaults to false.
+* `idp_name`: A user-facing name for this identity provider, which is used to
+   offer the user a choice of login mechanisms.
+* `idp_icon`: An optional icon for this identity provider, which is presented
+   by clients and Synapse's own IdP picker page. If given, must be an
+   MXC URI of the format `mxc://<server-name>/<media-id>`. (An easy way to
+   obtain such an MXC URI is to upload an image to an (unencrypted) room
+   and then copy the "url" from the source of the event.)
+* `idp_brand`: An optional brand for this identity provider, allowing clients
+   to style the login flow according to the identity provider in question.
+   See the [spec](https://spec.matrix.org/latest/) for possible options here.
 * `server_url`: The URL of the CAS authorization endpoint.
 * `displayname_attribute`: The attribute of the CAS response to use as the display name.
    If no name is given here, no displayname will be set.

synapse/config/cas.py

@@ -47,6 +47,10 @@ class CasConfig(Config):
                 required_attributes
             )
 
+            self.idp_name = cas_config.get("idp_name", "CAS")
+            self.idp_icon = cas_config.get("idp_icon")
+            self.idp_brand = cas_config.get("idp_brand")
+
         else:
             self.cas_server_url = None
             self.cas_service_url = None

synapse/config/saml2.py

@@ -89,8 +89,14 @@ class SAML2Config(Config):
             "grandfathered_mxid_source_attribute", "uid"
         )
 
+        # refers to a SAML IdP entity ID
         self.saml2_idp_entityid = saml2_config.get("idp_entityid", None)
 
+        # IdP properties for Matrix clients
+        self.idp_name = saml2_config.get("idp_name", "SAML")
+        self.idp_icon = saml2_config.get("idp_icon")
+        self.idp_brand = saml2_config.get("idp_brand")
+
         # user_mapping_provider may be None if the key is present but has no value
         ump_dict = saml2_config.get("user_mapping_provider") or {}
 

synapse/handlers/cas.py

@@ -76,12 +76,13 @@ class CasHandler:
         self.idp_id = "cas"
 
         # user-facing name of this auth provider
-        self.idp_name = "CAS"
+        self.idp_name = hs.config.cas.idp_name
 
-        # we do not currently support brands/icons for CAS auth, but this is required by
-        # the SsoIdentityProvider protocol type.
-        self.idp_icon = None
-        self.idp_brand = None
+        # MXC URI for icon for this auth provider
+        self.idp_icon = hs.config.cas.idp_icon
+
+        # optional brand identifier for this auth provider
+        self.idp_brand = hs.config.cas.idp_brand
 
         self._sso_handler = hs.get_sso_handler()
 

synapse/handlers/saml.py

@@ -74,12 +74,13 @@ class SamlHandler:
         self.idp_id = "saml"
 
         # user-facing name of this auth provider
-        self.idp_name = "SAML"
+        self.idp_name = hs.config.saml2.idp_name
 
-        # we do not currently support icons/brands for SAML auth, but this is required by
-        # the SsoIdentityProvider protocol type.
-        self.idp_icon = None
-        self.idp_brand = None
+        # MXC URI for icon for this auth provider
+        self.idp_icon = hs.config.saml2.idp_icon
+
+        # optional brand identifier for this auth provider
+        self.idp_brand = hs.config.saml2.idp_brand
 
         # a map from saml session id to Saml2SessionData object
         self._outstanding_requests_dict: Dict[str, Saml2SessionData] = {}