Adding information on ruleset signature file.

Hainish · Hainish · commit ffcd66a47b8e · 2018-09-04T18:53:20.000-07:00
diff --git a/docs/en_US/ruleset-update-channels.md b/docs/en_US/ruleset-update-channels.md
@@ -30,7 +30,7 @@ Update channels can be found in [`chromium/background-scripts/update_channels.js
 3. A `update_path_prefix` string, which tells the extension where to look for new rulesets
 4. A `scope` string, which is used to construct a JavaScript `RegExp` object
 
-Every 24 hours, the extension checks the URL contained in `update_path_prefix` appended with `/latest-rulesets-timestamp` (in the case of `EFF (Full)`, `https://www.https-rulesets.org/v1//latest-rulesets-timestamp`).  If it discovers the timestamp has updated since the last time it fetched the rulesets, it will download a new ruleset, following the format `update_path_prefix` appended with `default.rulesets.XXXXXXXXXX.gz`, where `XXXXXXXXXX` is the timestamp discovered in the previous request.
+Every 24 hours, the extension checks the URL contained in `update_path_prefix` appended with `/latest-rulesets-timestamp` (in the case of `EFF (Full)`, `https://www.https-rulesets.org/v1//latest-rulesets-timestamp`).  If it discovers the timestamp has updated since the last time it fetched the rulesets, it will download a new ruleset, following the format `update_path_prefix` appended with `default.rulesets.XXXXXXXXXX.gz`, where `XXXXXXXXXX` is the timestamp discovered in the previous request.  At the same time, a corresponding signature for that file is downloaded, `update_path_prefix` appended with `rulesets-signature.XXXXXXXXXX.sha256`, again with the timestamp replacing the `XXXXXXXXXX`.
 
 It then attempts to verify the rulesets, which are signed with the private RSA key corresponding to the public key in the update channel's `jwk` object.  If the signature verifies, the rulesets are stored and applied to the running instance of the extension.  If it can not be verified, the rulesets are discarded and the last known good state is used.
 
