From 6df47d6151b9050efaf3aef7b77554c1a310118a Mon Sep 17 00:00:00 2001
From: Johann <git@johann-hofmann.com>
Date: Wed, 23 Sep 2015 18:42:20 +0200
Subject: [PATCH] crypto: add more keylen sanity checks in pbkdf2

issue #2987 makes the point that crypto.pbkdf2 should not fail silently
and accept invalid but numeric values like NaN and Infinity. We already
check if the keylen is lower than 0, so extending that to NaN and
Infinity should make sense.

Fixes: https://github.com/nodejs/node/issues/2987

PR-URL: https://github.com/nodejs/node/pull/3029
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Brian White <mscdex@mscdex.net>
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
---
 src/node_crypto.cc                  |  9 +++++----
 test/parallel/test-crypto-pbkdf2.js | 28 ++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/src/node_crypto.cc b/src/node_crypto.cc
index cb5ef574a17..4cfb977f740 100644
--- a/src/node_crypto.cc
+++ b/src/node_crypto.cc
@@ -19,6 +19,7 @@
 #include "CNNICHashWhitelist.inc"
 
 #include <errno.h>
+#include <math.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -4760,7 +4761,7 @@ void PBKDF2(const FunctionCallbackInfo<Value>& args) {
   char* salt = nullptr;
   ssize_t passlen = -1;
   ssize_t saltlen = -1;
-  ssize_t keylen = -1;
+  double keylen = -1;
   ssize_t iter = -1;
   PBKDF2Request* req = nullptr;
   Local<Object> obj;
@@ -4813,8 +4814,8 @@ void PBKDF2(const FunctionCallbackInfo<Value>& args) {
     goto err;
   }
 
-  keylen = args[3]->Int32Value();
-  if (keylen < 0) {
+  keylen = args[3]->NumberValue();
+  if (keylen < 0 || isnan(keylen) || isinf(keylen)) {
     type_error = "Bad key length";
     goto err;
   }
@@ -4841,7 +4842,7 @@ void PBKDF2(const FunctionCallbackInfo<Value>& args) {
                           saltlen,
                           salt,
                           iter,
-                          keylen);
+                          static_cast<ssize_t>(keylen));
 
   if (args[5]->IsFunction()) {
     obj->Set(env->ondone_string(), args[5]);
diff --git a/test/parallel/test-crypto-pbkdf2.js b/test/parallel/test-crypto-pbkdf2.js
index 885831bad16..51759ca8357 100644
--- a/test/parallel/test-crypto-pbkdf2.js
+++ b/test/parallel/test-crypto-pbkdf2.js
@@ -59,3 +59,31 @@ function ondone(err, key) {
 assert.throws(function() {
   crypto.pbkdf2('password', 'salt', 1, 20, null);
 });
+
+// Should not work with Infinity key length
+assert.throws(function() {
+  crypto.pbkdf2('password', 'salt', 1, Infinity, assert.fail);
+}, function(err) {
+  return err instanceof Error && err.message === 'Bad key length';
+});
+
+// Should not work with negative Infinity key length
+assert.throws(function() {
+  crypto.pbkdf2('password', 'salt', 1, -Infinity, assert.fail);
+}, function(err) {
+  return err instanceof Error && err.message === 'Bad key length';
+});
+
+// Should not work with NaN key length
+assert.throws(function() {
+  crypto.pbkdf2('password', 'salt', 1, NaN, assert.fail);
+}, function(err) {
+  return err instanceof Error && err.message === 'Bad key length';
+});
+
+// Should not work with negative key length
+assert.throws(function() {
+  crypto.pbkdf2('password', 'salt', 1, -1, assert.fail);
+}, function(err) {
+  return err instanceof Error && err.message === 'Bad key length';
+});