Add keylog support to the Send API

Author: pimterry

src/client/client-types.ts

@@ -82,6 +82,11 @@ export interface RequestOptions {
      */
     lookupOptions?: { servers?: string[] };
 
+    /**
+     * A path to a file where TLS key logging information should be written.
+     */
+    keyLogFile?: string;
+
     /**
      * An abort signal, which can be used to cancel the in-process request if
      * required.

src/client/http-client.ts

@@ -22,6 +22,7 @@ import {
     RequestOptions,
     RULE_PARAM_REF_KEY
 } from './client-types';
+import * as fs from '../util/fs';
 
 export class HttpClient {
 
@@ -102,6 +103,12 @@ export class HttpClient {
             })
         });
 
+        if (options.keyLogFile) {
+            request.on('socket', (socket) => {
+                socket.on('keylog', (line) => fs.appendOrCreateFile(options.keyLogFile!, line));
+            });
+        }
+
         options.abortSignal?.addEventListener('abort', () => {
             // In older Node versions, this seems to be required to _actually_ abort the request:
             request.abort();