Files
ce_cdm/core/include/policy_engine.h
Joey Parrish 66794025d4 Initial source release: v2.0.8-0-679
Change-Id: Idf6316a8faf4b4fdc54265aad12084e5aa60707a
2014-05-20 11:08:09 -07:00

122 lines
4.3 KiB
C++

// Copyright 2013 Google Inc. All Rights Reserved.
#ifndef WVCDM_CORE_POLICY_ENGINE_H_
#define WVCDM_CORE_POLICY_ENGINE_H_
#include <string>
#include "license_protocol.pb.h"
#include "wv_cdm_types.h"
namespace wvcdm {
class Clock;
class PolicyEngineTest;
// This acts as an oracle that basically says "Yes(true) you may still decrypt
// or no(false) you may not decrypt this data anymore."
class PolicyEngine {
public:
PolicyEngine();
~PolicyEngine();
// The value returned should be taken as a hint rather than an absolute
// status. It is computed during the last call to either SetLicense/
// UpdateLicense/OnTimerEvent/BeginDecryption and may be out of sync
// depending on the amount of time elapsed. The current decryption
// status is not calculated to avoid overhead in the decryption path.
inline bool can_decrypt() { return can_decrypt_; }
// OnTimerEvent is called when a timer fires. It notifies the Policy Engine
// that the timer has fired and that it should check whether any events have
// occurred since the last timer event. If so, it sets event_occurred to true
// and sets event to point to the event that occurred. If not, it sets
// event_occurred to false.
void OnTimerEvent(bool* event_occurred, CdmEventType* event);
// SetLicense is used in handling the initial license response. It stores
// an exact copy of the policy information stored in the license.
// The license state transitions to kLicenseStateCanPlay if the license
// permits playback.
void SetLicense(const video_widevine_server::sdk::License& license);
// Call this on first decrypt to set the start of playback. This is
// for cases where usage begins not when the license is received,
// but at the start of playback
void BeginDecryption(void);
// UpdateLicense is used in handling a license response for a renewal request.
// The response may only contain any policy fields that have changed. In this
// case an exact copy is not what we want to happen. We also will receive an
// updated license_start_time from the server. The license will transition to
// kLicenseStateCanPlay if the license permits playback.
void UpdateLicense(const video_widevine_server::sdk::License& license);
CdmResponseType Query(CdmQueryMap* key_info);
const video_widevine_server::sdk::LicenseIdentification& license_id() {
return license_id_;
}
bool IsLicenseDurationExpired(int64_t current_time);
bool IsPlaybackDurationExpired(int64_t current_time);
private:
typedef enum {
kLicenseStateInitial,
kLicenseStateInitialPendingUsage,
kLicenseStateCanPlay,
kLicenseStateNeedRenewal,
kLicenseStateWaitingLicenseUpdate,
kLicenseStateExpired
} LicenseState;
void Init(Clock* clock);
bool IsRenewalDelayExpired(int64_t current_time);
bool IsRenewalRecoveryDurationExpired(int64_t current_time);
bool IsRenewalRetryIntervalExpired(int64_t current_time);
void UpdateRenewalRequest(int64_t current_time);
LicenseState license_state_;
bool can_decrypt_;
// This is the current policy information for this license. This gets updated
// as license renewals occur.
video_widevine_server::sdk::License::Policy policy_;
// This is the license id field from server response. This data gets passed
// back to the server in each renewal request. When we get a renewal response
// from the license server we will get an updated id field.
video_widevine_server::sdk::LicenseIdentification license_id_;
// This is the license start time that gets sent from the server in each
// license request or renewal.
int64_t license_start_time_;
// This is the time at which the license was received and playback was
// started. These times are based off the local clock in case there is a
// discrepency between local and server time.
int64_t license_received_time_;
int64_t playback_start_time_;
// This is used as a reference point for policy management. This value
// represents an offset from license_received_time_. This is used to
// calculate the time where renewal retries should occur.
int64_t next_renewal_time_;
int64_t policy_max_duration_seconds_;
Clock* clock_;
// For testing
friend class PolicyEngineTest;
PolicyEngine(Clock* clock);
CORE_DISALLOW_COPY_AND_ASSIGN(PolicyEngine);
};
} // wvcdm
#endif // WVCDM_CORE_POLICY_ENGINE_H_