From 768c98627f01aa2ad055b21479102b8d2e6d5a9c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tobias=20Nie=C3=9Fen?= <tniessen@tnie.de>
Date: Sun, 2 Apr 2017 15:00:32 +0200
Subject: [PATCH] crypto: handle exceptions in hmac/hash.digest

Forced conversion of the encoding parameter to a string within
crypto.js, fixing segmentation faults in node_crypto.cc.

Fixes: https://github.com/nodejs/node/issues/9819
---
 lib/crypto.js      |  3 ++-
 src/node.cc        |  2 ++
 src/node_crypto.cc | 18 +++++-------------
 3 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/lib/crypto.js b/lib/crypto.js
index 3e7ed5e9c86960..ca3a5ce4711bc0 100644
--- a/lib/crypto.js
+++ b/lib/crypto.js
@@ -100,7 +100,8 @@ Hash.prototype.update = function update(data, encoding) {
 
 Hash.prototype.digest = function digest(outputEncoding) {
   outputEncoding = outputEncoding || exports.DEFAULT_ENCODING;
-  return this._handle.digest(outputEncoding);
+  // Explicit conversion for backward compatibility
+  return this._handle.digest(String(outputEncoding));
 };
 
 
diff --git a/src/node.cc b/src/node.cc
index 77e6a5826ee957..8b143c4b0f52b3 100644
--- a/src/node.cc
+++ b/src/node.cc
@@ -1481,6 +1481,8 @@ enum encoding ParseEncoding(const char* encoding,
 enum encoding ParseEncoding(Isolate* isolate,
                             Local<Value> encoding_v,
                             enum encoding default_encoding) {
+  CHECK(!encoding_v.IsEmpty());
+
   if (!encoding_v->IsString())
     return default_encoding;
 
diff --git a/src/node_crypto.cc b/src/node_crypto.cc
index 45b06eaff50385..0c02e560cb0689 100644
--- a/src/node_crypto.cc
+++ b/src/node_crypto.cc
@@ -3797,9 +3797,7 @@ void Hmac::HmacDigest(const FunctionCallbackInfo<Value>& args) {
 
   enum encoding encoding = BUFFER;
   if (args.Length() >= 1) {
-    encoding = ParseEncoding(env->isolate(),
-                             args[0]->ToString(env->isolate()),
-                             BUFFER);
+    encoding = ParseEncoding(env->isolate(), args[0], BUFFER);
   }
 
   unsigned char* md_value = nullptr;
@@ -3921,9 +3919,7 @@ void Hash::HashDigest(const FunctionCallbackInfo<Value>& args) {
 
   enum encoding encoding = BUFFER;
   if (args.Length() >= 1) {
-    encoding = ParseEncoding(env->isolate(),
-                             args[0]->ToString(env->isolate()),
-                             BUFFER);
+    encoding = ParseEncoding(env->isolate(), args[0], BUFFER);
   }
 
   unsigned char md_value[EVP_MAX_MD_SIZE];
@@ -4201,10 +4197,8 @@ void Sign::SignFinal(const FunctionCallbackInfo<Value>& args) {
 
   unsigned int len = args.Length();
   enum encoding encoding = BUFFER;
-  if (len >= 2 && args[1]->IsString()) {
-    encoding = ParseEncoding(env->isolate(),
-                             args[1]->ToString(env->isolate()),
-                             BUFFER);
+  if (len >= 2) {
+    encoding = ParseEncoding(env->isolate(), args[1], BUFFER);
   }
 
   node::Utf8Value passphrase(env->isolate(), args[2]);
@@ -4452,9 +4446,7 @@ void Verify::VerifyFinal(const FunctionCallbackInfo<Value>& args) {
 
   enum encoding encoding = UTF8;
   if (args.Length() >= 3) {
-    encoding = ParseEncoding(env->isolate(),
-                             args[2]->ToString(env->isolate()),
-                             UTF8);
+    encoding = ParseEncoding(env->isolate(), args[2], UTF8);
   }
 
   ssize_t hlen = StringBytes::Size(env->isolate(), args[1], encoding);