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// Copyright (c) 2012 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 <cstring> // For std::memcpy.
#include "base/compiler_specific.h" // For OVERRIDE.
#include "ppapi/c/pp_errors.h"
#include "ppapi/c/pp_stdint.h"
#include "ppapi/c/private/pp_content_decryptor.h"
#include "ppapi/cpp/completion_callback.h"
#include "ppapi/cpp/core.h"
#include "ppapi/cpp/instance.h"
#include "ppapi/cpp/logging.h"
#include "ppapi/cpp/module.h"
#include "ppapi/cpp/pass_ref.h"
#include "ppapi/cpp/resource.h"
#include "ppapi/cpp/var.h"
#include "ppapi/cpp/var_array_buffer.h"
#include "ppapi/cpp/dev/buffer_dev.h"
#include "ppapi/cpp/private/content_decryptor_private.h"
#include "ppapi/utility/completion_callback_factory.h"
namespace {
struct DecryptorMessage {
DecryptorMessage() : media_error(0), system_code(0) {}
std::string key_system;
std::string session_id;
std::string default_url;
std::string message_data;
int32_t media_error;
int32_t system_code;
};
struct DecryptedBlock {
DecryptedBlock() {
std::memset(reinterpret_cast<void*>(&decrypted_block_info),
0,
sizeof(decrypted_block_info));
}
std::string decrypted_data;
PP_DecryptedBlockInfo decrypted_block_info;
};
bool IsMainThread() {
return pp::Module::Get()->core()->IsMainThread();
}
void CallOnMain(pp::CompletionCallback cb) {
// TODO(tomfinegan): This is only necessary because PPAPI doesn't allow calls
// off the main thread yet. Remove this once the change lands.
if (IsMainThread())
cb.Run(PP_OK);
else
pp::Module::Get()->core()->CallOnMainThread(0, cb, PP_OK);
}
} // namespace
// A wrapper class for abstracting away PPAPI interaction and threading for a
// Content Decryption Module (CDM).
class CDMWrapper : public pp::Instance,
public pp::ContentDecryptor_Private {
public:
CDMWrapper(PP_Instance instance, pp::Module* module);
virtual ~CDMWrapper() {}
// PPP_ContentDecryptor_Private methods
virtual bool GenerateKeyRequest(const std::string& key_system,
pp::VarArrayBuffer init_data) OVERRIDE;
virtual bool AddKey(const std::string& session_id,
pp::VarArrayBuffer key,
pp::VarArrayBuffer init_data) OVERRIDE;
virtual bool CancelKeyRequest(const std::string& session_id) OVERRIDE;
virtual bool Decrypt(
pp::Buffer_Dev encrypted_buffer,
const PP_EncryptedBlockInfo& encrypted_block_info) OVERRIDE;
virtual bool DecryptAndDecode(
pp::Buffer_Dev encrypted_buffer,
const PP_EncryptedBlockInfo& encrypted_block_info) OVERRIDE {
return false;
}
virtual bool Init(uint32_t argc, const char* argn[], const char* argv[]) {
return true;
}
private:
PP_Resource StringToBufferResource(const std::string& str);
// <code>PPB_ContentDecryptor_Private</code> dispatchers. These are passed to
// <code>callback_factory_</code> to ensure that calls into
// <code>PPP_ContentDecryptor_Private</code> are asynchronous.
void NeedKey(int32_t result, const DecryptorMessage& decryptor_message);
void KeyAdded(int32_t result, const DecryptorMessage& decryptor_message);
void KeyMessage(int32_t result, const DecryptorMessage& decryptor_message);
void KeyError(int32_t result, const DecryptorMessage& decryptor_message);
void DeliverBlock(int32_t result, const DecryptedBlock& decrypted_block);
pp::CompletionCallbackFactory<CDMWrapper> callback_factory_;
};
CDMWrapper::CDMWrapper(PP_Instance instance,
pp::Module* module)
: pp::Instance(instance),
pp::ContentDecryptor_Private(this) {
callback_factory_.Initialize(this);
}
bool CDMWrapper::GenerateKeyRequest(const std::string& key_system,
pp::VarArrayBuffer init_data) {
PP_DCHECK(!key_system.empty() && init_data.ByteLength());
DecryptorMessage decryptor_message;
decryptor_message.key_system = key_system;
decryptor_message.session_id = "0";
decryptor_message.default_url = "http://www.google.com";
decryptor_message.message_data = "GenerateKeyRequest";
CallOnMain(callback_factory_.NewCallback(&CDMWrapper::KeyMessage,
decryptor_message));
return true;
}
bool CDMWrapper::AddKey(const std::string& session_id,
pp::VarArrayBuffer key,
pp::VarArrayBuffer init_data) {
const std::string key_string(reinterpret_cast<char*>(key.Map()),
key.ByteLength());
const std::string init_data_string(reinterpret_cast<char*>(init_data.Map()),
init_data.ByteLength());
PP_DCHECK(!session_id.empty() && !key_string.empty());
DecryptorMessage decryptor_message;
decryptor_message.key_system = "AddKey";
decryptor_message.session_id = "0";
decryptor_message.default_url = "http://www.google.com";
decryptor_message.message_data = "AddKey";
CallOnMain(callback_factory_.NewCallback(&CDMWrapper::KeyAdded,
decryptor_message));
return true;
}
bool CDMWrapper::CancelKeyRequest(const std::string& session_id) {
// TODO(tomfinegan): cancel pending key request in CDM.
PP_DCHECK(!session_id.empty());
DecryptorMessage decryptor_message;
decryptor_message.key_system = "CancelKeyRequest";
decryptor_message.session_id = "0";
decryptor_message.default_url = "http://www.google.com";
decryptor_message.message_data = "CancelKeyRequest";
CallOnMain(callback_factory_.NewCallback(&CDMWrapper::KeyMessage,
decryptor_message));
return true;
}
bool CDMWrapper::Decrypt(pp::Buffer_Dev encrypted_buffer,
const PP_EncryptedBlockInfo& encrypted_block_info) {
PP_DCHECK(!encrypted_buffer.is_null());
DecryptedBlock decrypted_block;
decrypted_block.decrypted_data = "Pretend I'm decrypted data!";
decrypted_block.decrypted_block_info.result = PP_DECRYPTRESULT_SUCCESS;
decrypted_block.decrypted_block_info.tracking_info =
encrypted_block_info.tracking_info;
// TODO(tomfinegan): This would end up copying a lot of data in the real
// implementation if we continue passing std::strings around. It *might* not
// be such a big deal w/a real CDM. We may be able to simply pass a pointer
// into the CDM. Otherwise we could look into using std::tr1::shared_ptr
// instead of passing a giant std::string filled with encrypted data.
CallOnMain(callback_factory_.NewCallback(&CDMWrapper::DeliverBlock,
decrypted_block));
return true;
}
PP_Resource CDMWrapper::StringToBufferResource(const std::string& str) {
if (str.empty())
return 0;
pp::Buffer_Dev buffer(this, str.size());
if (!buffer.data())
return 0;
std::memcpy(buffer.data(), str.data(), str.size());
return buffer.detach();
}
void CDMWrapper::NeedKey(int32_t result,
const DecryptorMessage& decryptor_message) {
const std::string& message_data = decryptor_message.message_data;
pp::VarArrayBuffer init_data(message_data.size());
std::memcpy(init_data.Map(), message_data.data(), message_data.size());
pp::ContentDecryptor_Private::NeedKey(decryptor_message.key_system,
decryptor_message.session_id,
init_data);
}
void CDMWrapper::KeyAdded(int32_t result,
const DecryptorMessage& decryptor_message) {
pp::ContentDecryptor_Private::KeyAdded(decryptor_message.key_system,
decryptor_message.session_id);
}
void CDMWrapper::KeyMessage(int32_t result,
const DecryptorMessage& decryptor_message) {
pp::Buffer_Dev message_buffer(
StringToBufferResource(decryptor_message.message_data));
pp::ContentDecryptor_Private::KeyMessage(decryptor_message.key_system,
decryptor_message.session_id,
message_buffer,
decryptor_message.default_url);
}
void CDMWrapper::KeyError(int32_t result,
const DecryptorMessage& decryptor_message) {
pp::ContentDecryptor_Private::KeyError(decryptor_message.key_system,
decryptor_message.session_id,
decryptor_message.media_error,
decryptor_message.system_code);
}
void CDMWrapper::DeliverBlock(int32_t result,
const DecryptedBlock& decrypted_block) {
pp::Buffer_Dev decrypted_buffer(
StringToBufferResource(decrypted_block.decrypted_data));
pp::ContentDecryptor_Private::DeliverBlock(
decrypted_buffer,
decrypted_block.decrypted_block_info);
}
// This object is the global object representing this plugin library as long
// as it is loaded.
class MyModule : public pp::Module {
public:
MyModule() : pp::Module() {}
virtual ~MyModule() {}
virtual pp::Instance* CreateInstance(PP_Instance instance) {
return new CDMWrapper(instance, this);
}
};
namespace pp {
// Factory function for your specialization of the Module object.
Module* CreateModule() {
return new MyModule();
}
} // namespace pp
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