Cast: Adding helper crypto classes

media/cast/transport/transport_encryption_handler.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/cast/transport/transport_encryption_handler.h"
+
+#include "base/logging.h"
+#include "crypto/encryptor.h"
+#include "crypto/symmetric_key.h"
+#include "media/cast/transport/cast_transport_defines.h"
+
+namespace media {
+namespace cast {
+namespace transport {
+
+TransportEncryptionHandler::TransportEncryptionHandler()
+    : key_(),
+      encryptor_(),
+      iv_mask_(),
+      initialized_(false) {}
+
+TransportEncryptionHandler::~TransportEncryptionHandler() {}
+
+bool TransportEncryptionHandler::Initialize(std::string aes_key,
+                                        std::string aes_iv_mask) {

[hubbe, 2014/01/31 17:46:22]

indentation?

[mikhal1, 2014/01/31 18:22:47]

Done.

+  initialized_ = false;
+  if (aes_iv_mask.size() == kAesKeySize && aes_key.size() == kAesKeySize) {
+    iv_mask_ = aes_iv_mask;
+    key_.reset(
+        crypto::SymmetricKey::Import(crypto::SymmetricKey::AES, aes_key));
+    encryptor_.reset(new crypto::Encryptor());
+    encryptor_->Init(key_.get(), crypto::Encryptor::CTR, std::string());
+    initialized_ = true;
+  } else if (aes_iv_mask.size() != 0 || aes_key.size() != 0) {
+    DCHECK_EQ(aes_iv_mask.size(), 0u)
+        << "Invalid Crypto configuration: aes_iv_mask.size";
+    DCHECK_EQ(aes_key.size(), 0u)
+        << "Invalid Crypto configuration: aes_key.size";
+    return false;
+  }
+  return true;
+}
+
+bool TransportEncryptionHandler::Encrypt(uint32 frame_id,
+                                     std::string data,

[hubbe, 2014/01/31 17:46:22]

indentation?

[mikhal1, 2014/01/31 18:22:47]

Done.

+                                     std::string* encrypted_data) {
+  if (!initialized_)
+    return false;
+  if (!encryptor_->SetCounter(GetAesNonce(frame_id, iv_mask_))) {
+    NOTREACHED() << "Failed to set counter";
+    return false;
+  }
+  if (!encryptor_->Encrypt(data, encrypted_data)) {
+    NOTREACHED() << "Encrypt error";
+    return false;
+  }
+  return true;
+}
+
+}  // namespace transport
+}  // namespace cast
+}  // namespace media