Bug 1918455 - collect telemetry for how often TLS key logging has been enabled via SSLKEYLOGFILE r=Gijs,firefox-desktop-core-reviewers

Differential Revision: https://phabricator.services.mozilla.com/D222003

browser/components/BrowserGlue.sys.mjs

@@ -3311,6 +3311,13 @@ BrowserGlue.prototype = {
         },
       },
 
+      {
+        name: "SSLKEYLOGFILE telemetry",
+        task: () => {
+          Glean.sslkeylogging.enabled.set(Services.env.exists("SSLKEYLOGFILE"));
+        },
+      },
+
       {
         name: "browser-startup-idle-tasks-finished",
         task: () => {

browser/components/metrics.yaml

@@ -98,3 +98,19 @@ start_menu:
     send_in_pings:
       - events
     lifetime: ping
+
+sslkeylogging:
+  enabled:
+    type: boolean
+    description: >
+      Records whether TLS key logging has been enabled via the environment
+      variable SSLKEYLOGFILE.
+    bugs:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1918455
+    data_reviews:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1918455
+    data_sensitivity:
+      - technical
+    notification_emails:
+      - dkeeler@mozilla.com
+    expires: never