crypto: clear errors from verify failure

OpenSSL will push errors onto the stack when a verify fails, which can
disrupt TLS and other routines if we don't clear the error stack

Fixes #6304

Author: tjfontaine

src/node_crypto.cc

@@ -3186,6 +3186,9 @@ class Verify : public ObjectWrap {
   int VerifyFinal(char* key_pem, int key_pemLen, unsigned char* sig, int siglen) {
     if (!initialised_) return 0;
 
+    ClearErrorOnReturn clear_error_on_return;
+    (void) &clear_error_on_return;  // Silence compiler warning.
+
     EVP_PKEY* pkey = NULL;
     BIO *bp = NULL;
     X509 *x509 = NULL;

test/simple/test-crypto-verify-failure.js

@@ -0,0 +1,81 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+
+
+
+var common = require('../common');
+var assert = require('assert');
+
+try {
+  var crypto = require('crypto');
+  var tls = require('tls');
+} catch (e) {
+  console.log('Not compiled with OPENSSL support.');
+  process.exit();
+}
+
+crypto.DEFAULT_ENCODING = 'buffer';
+
+var fs = require('fs');
+
+var certPem = fs.readFileSync(common.fixturesDir + '/test_cert.pem', 'ascii');
+
+var options = {
+  key: fs.readFileSync(common.fixturesDir + '/keys/agent1-key.pem'),
+  cert: fs.readFileSync(common.fixturesDir + '/keys/agent1-cert.pem')
+};
+
+var canSend = true;
+
+var server = tls.Server(options, function(socket) {
+  process.nextTick(function() {
+      console.log('sending');
+      socket.destroy();
+      verify();
+  });
+});
+
+var client;
+
+function verify() {
+  console.log('verify');
+  var verified = crypto.createVerify('RSA-SHA1')
+                     .update('Test')
+                     .verify(certPem, 'asdfasdfas', 'base64');
+}
+
+server.listen(common.PORT, function() {
+  client = tls.connect({
+    port: common.PORT,
+    rejectUnauthorized: false
+  }, function() {
+    verify();
+  }).on('data', function(data) {
+    console.log(data);
+  }).on('error', function(err) {
+    throw err;
+  }).on('close', function() {
+    server.close();
+  }).resume();
+});
+
+server.unref();