Files
android/libwvdrmengine/cdm/core/include/cdm_session.h
Rahul Frias aefd104981 Use session with longest remaining duration when session sharing is used.
[ Merge of https://go/wvgerrit/16940 ]

An alternate scenario to renewing keys is to load the same keys in
a separate session and make use of them by using the session sharing
feature.

Session sharing involves iterating through a map of sessions and
returning the first session that contains the Key ID. In certain cases
(license about to expire) we might prefer an alternate session
be chosen.

Licenses may expire in two ways. Policy engine, driven by a 1 second
timer may detect expiry and send an asynchronous event. OEMCrypto may
also detect expiry based on information in the key control block
and return an error during decryption. It is possible that these
may differ by upto a second. This can lead to issues where decryption
fails but EVENT_KEY_EXPIRED is not generated till later.

It is possible to address this by using information from both timers
to notify the app about expiry. To implement this correctly will
add complexity and require synchronization between threads. To avoid
this an alternate solution is, if session sharing is used, to pick
the session that has a license with the longest remaining validity.

b/27041140

Change-Id: I398cc4c10ee3a2f192d4a0befe7c8a469dd5bf86
2016-02-24 10:22:18 -08:00

194 lines
6.7 KiB
C++

// Copyright 2012 Google Inc. All Rights Reserved.
#ifndef WVCDM_CORE_CDM_SESSION_H_
#define WVCDM_CORE_CDM_SESSION_H_
#include <set>
#include <string>
#include "crypto_session.h"
#include "device_files.h"
#include "initialization_data.h"
#include "license.h"
#include "oemcrypto_adapter.h"
#include "policy_engine.h"
#include "scoped_ptr.h"
#include "wv_cdm_types.h"
namespace wvcdm {
class CdmClientPropertySet;
class WvCdmEventListener;
class CdmSession {
public:
CdmSession(const std::string& origin)
: initialized_(false),
origin_(origin),
crypto_session_(new CryptoSession),
file_handle_(new DeviceFiles),
license_received_(false),
is_offline_(false),
is_release_(false),
is_temporary_(false),
security_level_(kSecurityLevelUninitialized),
requested_security_level_(kLevelDefault),
is_initial_decryption_(true),
has_decrypted_since_last_report_(false),
is_initial_usage_update_(true),
is_usage_update_needed_(false),
mock_license_parser_in_use_(false),
mock_policy_engine_in_use_(false) {}
virtual ~CdmSession();
virtual CdmResponseType Init(CdmClientPropertySet* cdm_client_property_set);
virtual CdmResponseType Init(CdmClientPropertySet* cdm_client_property_set,
const CdmSessionId* forced_session_id,
WvCdmEventListener* event_listener);
virtual CdmResponseType RestoreOfflineSession(
const CdmKeySetId& key_set_id, const CdmLicenseType license_type);
virtual CdmResponseType RestoreUsageSession(
const CdmKeyMessage& key_request, const CdmKeyResponse& key_response);
virtual const CdmSessionId& session_id() { return session_id_; }
virtual const CdmKeySetId& key_set_id() { return key_set_id_; }
virtual CdmResponseType GenerateKeyRequest(
const InitializationData& init_data, CdmLicenseType license_type,
const CdmAppParameterMap& app_parameters, CdmKeyRequest* key_request);
// AddKey() - Accept license response and extract key info.
virtual CdmResponseType AddKey(const CdmKeyResponse& key_response);
// Query session status
virtual CdmResponseType QueryStatus(CdmQueryMap* key_info);
// Query license information
virtual CdmResponseType QueryKeyStatus(CdmQueryMap* key_info);
// Query session control info
virtual CdmResponseType QueryKeyControlInfo(CdmQueryMap* key_info);
// Decrypt() - Accept encrypted buffer and return decrypted data.
virtual CdmResponseType Decrypt(const CdmDecryptionParameters& parameters);
// License renewal
// GenerateRenewalRequest() - Construct valid renewal request for the current
// session keys.
virtual CdmResponseType GenerateRenewalRequest(CdmKeyRequest* key_request);
// RenewKey() - Accept renewal response and update key info.
virtual CdmResponseType RenewKey(const CdmKeyResponse& key_response);
// License release
// GenerateReleaseRequest() - Construct valid release request for the current
// session keys.
virtual CdmResponseType GenerateReleaseRequest(CdmKeyRequest* key_request);
// ReleaseKey() - Accept response and release key.
virtual CdmResponseType ReleaseKey(const CdmKeyResponse& key_response);
virtual bool IsKeyLoaded(const KeyId& key_id);
virtual int64_t GetDurationRemaining();
// Used for notifying the Policy Engine of resolution changes
virtual void NotifyResolution(uint32_t width, uint32_t height);
virtual void OnTimerEvent(bool update_usage);
virtual void OnKeyReleaseEvent(const CdmKeySetId& key_set_id);
virtual void GetApplicationId(std::string* app_id);
virtual SecurityLevel GetRequestedSecurityLevel() {
return requested_security_level_;
}
virtual CdmSecurityLevel GetSecurityLevel() { return security_level_; }
// Delete usage information for the list of tokens, |provider_session_tokens|.
virtual CdmResponseType DeleteMultipleUsageInformation(
const std::vector<std::string>& provider_session_tokens);
virtual CdmResponseType UpdateUsageInformation();
virtual bool is_initial_usage_update() { return is_initial_usage_update_; }
virtual bool is_usage_update_needed() { return is_usage_update_needed_; }
virtual void reset_usage_flags() {
is_initial_usage_update_ = false;
is_usage_update_needed_ = false;
}
virtual bool is_release() { return is_release_; }
virtual bool is_offline() { return is_offline_; }
virtual bool is_temporary() { return is_temporary_; }
virtual bool license_received() { return license_received_; }
// ReleaseCrypto() - Closes the underlying crypto session but leaves this
// object alive. It is invalid to call any method that requires a crypto
// session after calling this. Since calling this renders this object mostly
// useless, it is preferable to simply delete this object (which will also
// release the underlying crypto session) rather than call this method.
virtual CdmResponseType ReleaseCrypto();
bool DeleteLicense();
private:
friend class CdmSessionTest;
// Generate unique ID for each new session.
CdmSessionId GenerateSessionId();
bool GenerateKeySetId(CdmKeySetId* key_set_id);
CdmResponseType StoreLicense();
bool StoreLicense(DeviceFiles::LicenseState state);
// These setters are for testing only. Takes ownership of the pointers.
void set_license_parser(CdmLicense* license_parser);
void set_crypto_session(CryptoSession* crypto_session);
void set_policy_engine(PolicyEngine* policy_engine);
void set_file_handle(DeviceFiles* file_handle);
// instance variables
bool initialized_;
CdmSessionId session_id_;
const std::string origin_;
scoped_ptr<CdmLicense> license_parser_;
scoped_ptr<CryptoSession> crypto_session_;
scoped_ptr<PolicyEngine> policy_engine_;
scoped_ptr<DeviceFiles> file_handle_;
bool license_received_;
bool is_offline_;
bool is_release_;
bool is_temporary_;
CdmSecurityLevel security_level_;
SecurityLevel requested_security_level_;
CdmAppParameterMap app_parameters_;
// decryption and usage flags
bool is_initial_decryption_;
bool has_decrypted_since_last_report_; // ... last report to policy engine.
bool is_initial_usage_update_;
bool is_usage_update_needed_;
// information useful for offline and usage scenarios
CdmKeyMessage key_request_;
CdmKeyResponse key_response_;
// license type offline related information
CdmInitData offline_init_data_;
CdmKeyMessage offline_key_renewal_request_;
CdmKeyResponse offline_key_renewal_response_;
std::string offline_release_server_url_;
// license type release and offline related information
CdmKeySetId key_set_id_;
bool mock_license_parser_in_use_;
bool mock_policy_engine_in_use_;
CORE_DISALLOW_COPY_AND_ASSIGN(CdmSession);
};
} // namespace wvcdm
#endif // WVCDM_CORE_CDM_SESSION_H_