Stop using the nonce consistently for a URL

Nonces are now randomly generated, either in the page (for non-HTTP(S) pages)
or by a background module which stores them by tab and frame IDs. In order to
support the increased variance in nonce-generating methods and allow them to
be loaded from the background, handle_page_actions is now invoked separately
according to (non-)blocking mechanism.

3 files changed, 34 insertions, 2 deletions

diff --git a/background/nonce_store.js b/background/nonce_store.js
new file mode 100644
index 0000000..9370876
--- /dev/null
+++ b/background/nonce_store.js
@@ -0,0 +1,30 @@
+/**
+ * Central management of HTTP(S) nonces
+ *
+ * Copyright (C) 2021 jahoti
+ * Redistribution terms are gathered in the `copyright' file.
+ */
+
+/*
+ * IMPORTS_START
+ * IMPORT gen_nonce
+ * IMPORTS_END
+ */
+
+var nonces = {};
+
+function retrieve_nonce(tabId, frameId, update)
+{
+    let code = tabId + '.' + frameId;
+    console.log('Nonce for ' + code + ' ' + (update ? 'created/updated' : 'requested'));
+    if (update)
+        nonces[code] = gen_nonce();
+    
+    return nonces[code];
+}
+
+/*
+ * EXPORTS_START
+ * EXPORT retrieve_nonce
+ * EXPORTS_END
+ */
diff --git a/background/page_actions_server.js b/background/page_actions_server.js
index 2d9c333..d92b870 100644
--- a/background/page_actions_server.js
+++ b/background/page_actions_server.js
@@ -11,6 +11,7 @@
  * IMPORT TYPE_PREFIX
  * IMPORT CONNECTION_TYPE
  * IMPORT browser
+ * IMPORT retrieve_nonce
  * IMPORT listen_for_connection
  * IMPORT sha256
  * IMPORT get_query_best
@@ -137,6 +138,7 @@ function handle_message(port, message, handler)
 function new_connection(port)
 {
     console.log("new page actions connection!");
+    port.postMessage(['nonce', retrieve_nonce((port.sender.tab || '').id, port.sender.frameId)]);
     let handler = [];
     handler.push(m => handle_message(port, m, handler));
     port.onMessage.addListener(handler[0]);
diff --git a/background/policy_injector.js b/background/policy_injector.js
index eb67963..9f79425 100644
--- a/background/policy_injector.js
+++ b/background/policy_injector.js
@@ -11,7 +11,7 @@
  * IMPORT get_storage
  * IMPORT browser
  * IMPORT is_chrome
- * IMPORT gen_unique
+ * IMPORT retrieve_nonce
  * IMPORT url_item
  * IMPORT get_query_best
  * IMPORT csp_rule
@@ -45,7 +45,7 @@ function inject(details)
 
     const [pattern, settings] = query_best(url);
 
-    const nonce = gen_unique(url);
+    const nonce = retrieve_nonce(details.tabId, details.frameId, true);
     const rule = csp_rule(nonce);
 
     var headers;