Add check for password length in SecurityContext. Check return values from BoringSSL functions, thr…

tests/standalone/io/security_context_argument_test.dart

+// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import "package:expect/expect.dart";
+import "dart:io";
+
+String localFile(path) => Platform.script.resolve(path).toFilePath();
+
+bool printException(e) { print(e); return true; }
+bool argumentError(e) => e is ArgumentError;
+bool tlsException(e) => e is TlsException;
+
+void testUsePrivateKeyArguments() {
+    var c = new SecurityContext();
+    c.useCertificateChain(localFile('certificates/server_chain.pem'));
+    Expect.throws(() => c.usePrivateKey(
+          localFile('certificates/server_key.pem'), password: "dart" * 1000),
+        argumentError);
+    Expect.throws(() => c.usePrivateKey(
+          localFile('certificates/server_key.pem')),
+        tlsException);
+    Expect.throws(() => c.usePrivateKey(
+          localFile('certificates/server_key.pem'), password: "iHackSites"),
+        tlsException);
+    Expect.throws(() => c.usePrivateKey(
+          localFile('certificates/server_key_oops.pem'), password: "dartdart"),
+        tlsException);
+    Expect.throws(() => c.usePrivateKey(1), argumentError);
+    Expect.throws(() => c.usePrivateKey(null), argumentError);
+    Expect.throws(() => c.usePrivateKey(
+          localFile('certificates/server_key_oops.pem'), password: 3),
+        argumentError);
+    c.usePrivateKey(
+        localFile('certificates/server_key.pem'), password: "dartdart");
+}    
+
+void main() {
+  testUsePrivateKeyArguments();
+}