From ceace1f96eb0862a2944bc38c2e897974169f622 Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Tue, 20 Aug 2019 14:10:42 +0200
Subject: [PATCH] crypto: handle i2d_SSL_SESSION() error return

i2d_SSL_SESSION() can return a value <= 0 when the session is malformed
or otherwise invalid. Handle that case.

This change comes without a regression test because I couldn't figure
out a good way to generate an existing but invalid session in a timely
fashion.

Fixes: https://github.com/nodejs/node/issues/29202

PR-URL: https://github.com/nodejs/node/pull/29225
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
---
 src/node_crypto.cc | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/node_crypto.cc b/src/node_crypto.cc
index de301d77c229c1..5634d8b1dc5379 100644
--- a/src/node_crypto.cc
+++ b/src/node_crypto.cc
@@ -2317,11 +2317,12 @@ void SSLWrap<Base>::GetSession(const FunctionCallbackInfo<Value>& args) {
     return;
 
   int slen = i2d_SSL_SESSION(sess, nullptr);
-  CHECK_GT(slen, 0);
+  if (slen <= 0)
+    return;  // Invalid or malformed session.
 
   AllocatedBuffer sbuf = env->AllocateManaged(slen);
   unsigned char* p = reinterpret_cast<unsigned char*>(sbuf.data());
-  i2d_SSL_SESSION(sess, &p);
+  CHECK_LT(0, i2d_SSL_SESSION(sess, &p));
   args.GetReturnValue().Set(sbuf.ToBuffer().ToLocalChecked());
 }