From 67d21149a20fcad27100a5fd6dfa7c3de98a59cc 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
PR-URL: https://github.com/nodejs/node/pull/12164
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
---
 lib/crypto.js                         |  3 ++-
 src/node.cc                           |  2 ++
 src/node_crypto.cc                    | 20 +++++++-------------
 test/parallel/test-regress-GH-9819.js | 24 ++++++++++++++++++++++++
 4 files changed, 35 insertions(+), 14 deletions(-)
 create mode 100644 test/parallel/test-regress-GH-9819.js

diff --git a/lib/crypto.js b/lib/crypto.js
index 9180ce70dce12e..1d8e294bd7bfe6 100644
--- a/lib/crypto.js
+++ b/lib/crypto.js
@@ -78,7 +78,8 @@ 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(`${outputEncoding}`);
 };
 
 
diff --git a/src/node.cc b/src/node.cc
index 7a7f2451d8b45c..3190d371f5ad04 100644
--- a/src/node.cc
+++ b/src/node.cc
@@ -1443,6 +1443,8 @@ 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 a463a4667a63be..33732778af29ef 100644
--- a/src/node_crypto.cc
+++ b/src/node_crypto.cc
@@ -3769,9 +3769,8 @@ 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);
+    CHECK(args[0]->IsString());
+    encoding = ParseEncoding(env->isolate(), args[0], BUFFER);
   }
 
   unsigned char* md_value = nullptr;
@@ -3893,9 +3892,8 @@ 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);
+    CHECK(args[0]->IsString());
+    encoding = ParseEncoding(env->isolate(), args[0], BUFFER);
   }
 
   unsigned char md_value[EVP_MAX_MD_SIZE];
@@ -4118,10 +4116,8 @@ 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]);
@@ -4334,9 +4330,7 @@ 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);
diff --git a/test/parallel/test-regress-GH-9819.js b/test/parallel/test-regress-GH-9819.js
new file mode 100644
index 00000000000000..f043bc3b2848e7
--- /dev/null
+++ b/test/parallel/test-regress-GH-9819.js
@@ -0,0 +1,24 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const execFile = require('child_process').execFile;
+
+if (!common.hasCrypto) {
+  common.skip('missing crypto');
+  return;
+}
+
+const setup = 'const enc = { toString: () => { throw new Error("xyz"); } };';
+
+const scripts = [
+  'crypto.createHash("sha256").digest(enc)',
+  'crypto.createHmac("sha256", "msg").digest(enc)'
+];
+
+scripts.forEach((script) => {
+  const node = process.execPath;
+  const code = setup + ';' + script;
+  execFile(node, [ '-e', code ], common.mustCall((err, stdout, stderr) => {
+    assert(stderr.includes('Error: xyz'), 'digest crashes');
+  }));
+});