tls: get the local certificate after tls handshake

Add an API to get the local certificate chosen during TLS handshake from
the SSL context.

Fix: https://github.com/nodejs/node/issues/24095

PR-URL: https://github.com/nodejs/node/pull/24261
Fixes: https://github.com/nodejs/node/issues/24095
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/lib/_tls_wrap.js b/lib/_tls_wrap.js
index f0d86f3d87..2e32366028 100644
--- a/lib/_tls_wrap.js
+++ b/lib/_tls_wrap.js
@@ -660,7 +660,17 @@ TLSSocket.prototype.setSession = function(session) {
 TLSSocket.prototype.getPeerCertificate = function(detailed) {
   if (this._handle) {
     return common.translatePeerCertificate(
-      this._handle.getPeerCertificate(detailed));
+      this._handle.getPeerCertificate(detailed)) || {};
+  }
+
+  return null;
+};
+
+TLSSocket.prototype.getCertificate = function() {
+  if (this._handle) {
+    // It's not a peer cert, but the formatting is identical.
+    return common.translatePeerCertificate(
+      this._handle.getCertificate()) || {};
   }
 
   return null;