Allow overriding message shown in authentication dialog

This is much easier than writing a PolkitBackendActionLookup class and
installing an extension. On the downside it requires the caller to be
uid 0.

Example: http://people.freedesktop.org/~david/polkit-pass-messages.png

Signed-off-by: David Zeuthen <davidz@redhat.com>

3 files changed, 36 insertions, 0 deletions

diff --git a/docs/polkit/docbook-interface-org.freedesktop.PolicyKit1.Authority.xml b/docs/polkit/docbook-interface-org.freedesktop.PolicyKit1.Authority.xml
index b67225e..ee29c4c 100644
--- a/docs/polkit/docbook-interface-org.freedesktop.PolicyKit1.Authority.xml
+++ b/docs/polkit/docbook-interface-org.freedesktop.PolicyKit1.Authority.xml
@@ -596,6 +596,19 @@ Identifier for the action that <parameter>subject</parameter> is attempting to d
       <para>
 Details describing the action. Keys starting with <literal>polkit.</literal> are reserved for internal use and cannot be used.
       </para>
+      <para>
+        Known keys include <literal>polkit.message</literal> and
+        <literal>polkit.message.gettext-domain</literal> that can be
+        used to override the message shown to the user (the user might
+        be running an authentication agent in another locale than the
+        calling process so that's why both the message and gettext
+        domain is needed.
+      </para>
+      <para>
+        If non-empty, then the request will fail with
+        <link linkend="eggdbus-constant-Error.org.freedesktop.PolicyKit1.Error.Failed">org.freedesktop.PolicyKit1.Error.Failed</link>
+        unless the process doing the check itsef is sufficiently authorized (e.g. running as uid 0).
+      </para>
     </listitem>
   </varlistentry>
   <varlistentry>
diff --git a/src/polkit/polkitauthority.c b/src/polkit/polkitauthority.c
index cc24e6c..3dc257f 100644
--- a/src/polkit/polkitauthority.c
+++ b/src/polkit/polkitauthority.c
@@ -869,6 +869,17 @@ check_authorization_cb (GDBusProxy    *proxy,
  * from. You can then call
  * polkit_authority_check_authorization_finish() to get the result of
  * the operation.
+ *
+ * Known keys in @details include <literal>polkit.message</literal>
+ * and <literal>polkit.message.gettext-domain</literal> that can be
+ * used to override the message shown to the user (the user might be
+ * running an authentication agent in another locale than the calling
+ * process so that's why both the message and gettext domain is
+ * needed).
+ *
+ * If @details is non-empty then the request will fail with
+ * #POLKIT_ERROR_FAILED unless the process doing the check itsef is
+ * sufficiently authorized (e.g. running as uid 0).
  **/
 void
 polkit_authority_check_authorization (PolkitAuthority               *authority,
@@ -985,6 +996,9 @@ polkit_authority_check_authorization_finish (PolkitAuthority          *authority
  * operation to complete because it involves waiting for the user to
  * authenticate.
  *
+ * See polkit_authority_check_authorization_sync() for how @details is
+ * handled.
+ *
  * Returns: (transfer full): A #PolkitAuthorizationResult or %NULL if @error is set. Free with g_object_unref().
  */
 PolkitAuthorizationResult *
diff --git a/src/polkitbackend/polkitbackendinteractiveauthority.c b/src/polkitbackend/polkitbackendinteractiveauthority.c
index 59b2fb7..462f334 100644
--- a/src/polkitbackend/polkitbackendinteractiveauthority.c
+++ b/src/polkitbackend/polkitbackendinteractiveauthority.c
@@ -1743,6 +1743,7 @@ get_localized_data_for_challenge (PolkitBackendInteractiveAuthority *authority,
   gchar *message;
   gchar *icon_name;
   PolkitDetails *localized_details;
+  const gchar *message_to_use;
 
   priv = POLKIT_BACKEND_INTERACTIVE_AUTHORITY_GET_PRIVATE (authority);
 
@@ -1768,6 +1769,14 @@ get_localized_data_for_challenge (PolkitBackendInteractiveAuthority *authority,
     }
   g_setenv ("LANG", locale, TRUE);
 
+  message_to_use = polkit_details_lookup (details, "polkit.message");
+  if (message_to_use != NULL)
+    {
+      const gchar *gettext_domain;
+      gettext_domain = polkit_details_lookup (details, "polkit.message.gettext-domain");
+      message = g_strdup (g_dgettext (gettext_domain, message_to_use));
+    }
+
   /* call into extension points to get localized auth dialog data - the list is sorted by priority */
   action_lookup_list = get_action_lookup_list ();
   for (l = action_lookup_list; l != NULL; l = l->next)