From 2ea085595a946bc91a8eed426d25773429b623f1 Mon Sep 17 00:00:00 2001
From: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Date: Thu, 11 Aug 2016 00:46:06 +0530
Subject: [PATCH 1/2] tls: copy the Buffer object before using

`convertNPNProtocols` uses the `protocols` buffer object as it is, and
if it is modified outside of core, it might have an impact. This patch
makes a copy of the buffer object, before using it.
---
 lib/tls.js                                  |  3 ++-
 test/parallel/test-tls-basic-validations.js | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/lib/tls.js b/lib/tls.js
index 849daeb07f3456..72ee81b7aae3bb 100644
--- a/lib/tls.js
+++ b/lib/tls.js
@@ -53,7 +53,8 @@ exports.convertNPNProtocols = function(protocols, out) {
   }
   // If it's already a Buffer - store it
   if (protocols instanceof Buffer) {
-    out.NPNProtocols = protocols;
+    // copy new buffer not to be modified by user
+    out.NPNProtocols = Buffer.from(protocols);
   }
 };
 
diff --git a/test/parallel/test-tls-basic-validations.js b/test/parallel/test-tls-basic-validations.js
index fa0165b3706225..3454da571df458 100644
--- a/test/parallel/test-tls-basic-validations.js
+++ b/test/parallel/test-tls-basic-validations.js
@@ -38,3 +38,21 @@ assert.throws(() => tls.createServer({ticketKeys: new Buffer(0)}),
 
 assert.throws(() => tls.createSecurePair({}),
               /Error: First argument must be a tls module SecureContext/);
+
+{
+  const buffer = Buffer.from('abcd');
+  const out = {};
+  tls.convertALPNProtocols(buffer, out);
+  out.ALPNProtocols.write('efgh');
+  assert(buffer.equals(Buffer.from('abcd')));
+  assert(out.ALPNProtocols.equals(Buffer.from('efgh')));
+}
+
+{
+  const buffer = Buffer.from('abcd');
+  const out = {};
+  tls.convertNPNProtocols(buffer, out);
+  out.NPNProtocols.write('efgh');
+  assert(buffer.equals(Buffer.from('abcd')));
+  assert(out.NPNProtocols.equals(Buffer.from('efgh')));
+}

From 2ee392b0ee4e104d661924b09de48aae3c9dee04 Mon Sep 17 00:00:00 2001
From: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Date: Thu, 11 Aug 2016 07:59:02 +0530
Subject: [PATCH 2/2] fix review comments

---
 lib/tls.js | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/lib/tls.js b/lib/tls.js
index 72ee81b7aae3bb..765e1658ea9127 100644
--- a/lib/tls.js
+++ b/lib/tls.js
@@ -49,11 +49,9 @@ function convertProtocols(protocols) {
 exports.convertNPNProtocols = function(protocols, out) {
   // If protocols is Array - translate it into buffer
   if (Array.isArray(protocols)) {
-    protocols = convertProtocols(protocols);
-  }
-  // If it's already a Buffer - store it
-  if (protocols instanceof Buffer) {
-    // copy new buffer not to be modified by user
+    out.NPNProtocols = convertProtocols(protocols);
+  } else if (protocols instanceof Buffer) {
+    // Copy new buffer not to be modified by user.
     out.NPNProtocols = Buffer.from(protocols);
   }
 };
@@ -61,11 +59,9 @@ exports.convertNPNProtocols = function(protocols, out) {
 exports.convertALPNProtocols = function(protocols, out) {
   // If protocols is Array - translate it into buffer
   if (Array.isArray(protocols)) {
-    protocols = convertProtocols(protocols);
-  }
-  // If it's already a Buffer - store it
-  if (protocols instanceof Buffer) {
-    // copy new buffer not to be modified by user
+    out.ALPNProtocols = convertProtocols(protocols);
+  } else if (protocols instanceof Buffer) {
+    // Copy new buffer not to be modified by user.
     out.ALPNProtocols = Buffer.from(protocols);
   }
 };