android/libwvdrmengine/cdm/src/wv_content_decryption_module.cpp

// Copyright 2013 Google Inc. All Rights Reserved.

#include "wv_content_decryption_module.h"

#include "cdm_client_property_set.h"
#include "cdm_engine.h"
#include "initialization_data.h"
#include "license.h"
#include "log.h"
#include "properties.h"
#include "service_certificate.h"
#include "wv_cdm_constants.h"
#include "wv_cdm_event_listener.h"

namespace {
const int kCdmPolicyTimerDurationSeconds = 1;
}

namespace wvcdm {

Lock WvContentDecryptionModule::session_sharing_id_generation_lock_;

WvContentDecryptionModule::WvContentDecryptionModule() {}

WvContentDecryptionModule::~WvContentDecryptionModule() {
  DisablePolicyTimer(true);
}

bool WvContentDecryptionModule::IsSupported(const std::string& init_data_type) {
  return InitializationData(init_data_type).is_supported();
}

bool WvContentDecryptionModule::IsCenc(const std::string& init_data_type) {
  return InitializationData(init_data_type).is_cenc();
}

bool WvContentDecryptionModule::IsWebm(const std::string& init_data_type) {
  return InitializationData(init_data_type).is_webm();
}

bool WvContentDecryptionModule::IsHls(const std::string& init_data_type) {
  return InitializationData(init_data_type).is_hls();
}

CdmResponseType WvContentDecryptionModule::OpenSession(
    const CdmKeySystem& key_system, CdmClientPropertySet* property_set,
    const std::string& origin, WvCdmEventListener* event_listener,
    CdmSessionId* session_id) {
  if (property_set && property_set->is_session_sharing_enabled()) {
    AutoLock auto_lock(session_sharing_id_generation_lock_);
    if (property_set->session_sharing_id() == 0)
      property_set->set_session_sharing_id(GenerateSessionSharingId());
  }

  CdmEngine* cdm_engine = EnsureCdmForOrigin(origin);
  CdmResponseType sts = cdm_engine->OpenSession(key_system, property_set,
                                                event_listener, session_id);
  if (sts == NO_ERROR) {
    cdm_by_session_id_[*session_id] = cdm_engine;
  }
  return sts;
}

CdmResponseType WvContentDecryptionModule::CloseSession(
    const CdmSessionId& session_id) {
  CdmEngine* cdm_engine = GetCdmForSessionId(session_id);
  // TODO(rfrias): Avoid reusing the error codes from CdmEngine.
  if (!cdm_engine) return SESSION_NOT_FOUND_1;
  CdmResponseType sts = cdm_engine->CloseSession(session_id);
  if (sts == NO_ERROR) {
    cdm_by_session_id_.erase(session_id);
  }
  DisablePolicyTimer(false);
  return sts;
}

bool WvContentDecryptionModule::IsOpenSession(const CdmSessionId& session_id) {
  CdmEngine* cdm_engine = GetCdmForSessionId(session_id);
  return cdm_engine && cdm_engine->IsOpenSession(session_id);
}

CdmResponseType WvContentDecryptionModule::GenerateKeyRequest(
    const CdmSessionId& session_id, const CdmKeySetId& key_set_id,
    const std::string& init_data_type, const CdmInitData& init_data,
    const CdmLicenseType license_type, CdmAppParameterMap& app_parameters,
    CdmClientPropertySet* property_set, const std::string& origin,
    CdmKeyRequest* key_request) {
  CdmEngine* cdm_engine = EnsureCdmForOrigin(origin);
  CdmResponseType sts;
  if (license_type == kLicenseTypeRelease) {
    sts = cdm_engine->OpenKeySetSession(key_set_id, property_set, NULL);
    if (sts != NO_ERROR) return sts;
    cdm_by_session_id_[key_set_id] = cdm_engine;
  }
  InitializationData initialization_data(init_data_type, init_data);
  sts = cdm_engine->GenerateKeyRequest(
      session_id, key_set_id, initialization_data, license_type, app_parameters,
      key_request);

  switch(license_type) {
    case kLicenseTypeRelease:
      if (sts != KEY_MESSAGE) {
        cdm_engine->CloseKeySetSession(key_set_id);
        cdm_by_session_id_.erase(key_set_id);
      }
      break;
    default:
      if (sts == KEY_MESSAGE)
        EnablePolicyTimer();
      break;
  }
  return sts;
}

CdmResponseType WvContentDecryptionModule::AddKey(
    const CdmSessionId& session_id,
    const CdmKeyResponse& key_data,
    CdmKeySetId* key_set_id) {
  CdmEngine* cdm_engine = session_id.empty() ? GetCdmForSessionId(*key_set_id)
                                             : GetCdmForSessionId(session_id);
  if (!cdm_engine) return SESSION_NOT_FOUND_3;
  CdmResponseType sts = cdm_engine->AddKey(session_id, key_data, key_set_id);
  if (sts == KEY_ADDED && session_id.empty()) {  // license type release
    cdm_engine->CloseKeySetSession(*key_set_id);
    cdm_by_session_id_.erase(*key_set_id);
  }
  return sts;
}

CdmResponseType WvContentDecryptionModule::RestoreKey(
    const CdmSessionId& session_id,
    const CdmKeySetId& key_set_id) {
  CdmEngine* cdm_engine = GetCdmForSessionId(session_id);
  if (!cdm_engine) return SESSION_NOT_FOUND_4;
  CdmResponseType sts = cdm_engine->RestoreKey(session_id, key_set_id);
  if (sts == KEY_ADDED)
    EnablePolicyTimer();
  return sts;
}

CdmResponseType WvContentDecryptionModule::RemoveKeys(
    const CdmSessionId& session_id) {
  CdmEngine* cdm_engine = GetCdmForSessionId(session_id);
  if (!cdm_engine) return SESSION_NOT_FOUND_5;
  return cdm_engine->RemoveKeys(session_id);
}

CdmResponseType WvContentDecryptionModule::QueryStatus(
    SecurityLevel security_level,
    const std::string& key,
    std::string* value) {
  CdmEngine* cdm_engine = EnsureCdmForOrigin(EMPTY_ORIGIN);
  return cdm_engine->QueryStatus(security_level, key, value);
}

CdmResponseType WvContentDecryptionModule::QuerySessionStatus(
    const CdmSessionId& session_id, CdmQueryMap* key_info) {
  CdmEngine* cdm_engine = GetCdmForSessionId(session_id);
  if (!cdm_engine) return SESSION_NOT_FOUND_8;
  return cdm_engine->QuerySessionStatus(session_id, key_info);
}

CdmResponseType WvContentDecryptionModule::QueryKeyStatus(
    const CdmSessionId& session_id, CdmQueryMap* key_info) {
  CdmEngine* cdm_engine = GetCdmForSessionId(session_id);
  if (!cdm_engine) return SESSION_NOT_FOUND_9;
  return cdm_engine->QueryKeyStatus(session_id, key_info);
}

CdmResponseType WvContentDecryptionModule::QueryOemCryptoSessionId(
    const CdmSessionId& session_id, CdmQueryMap* response) {
  CdmEngine* cdm_engine = GetCdmForSessionId(session_id);
  if (!cdm_engine) return SESSION_NOT_FOUND_10;
  return cdm_engine->QueryOemCryptoSessionId(session_id, response);
}

CdmResponseType WvContentDecryptionModule::GetProvisioningRequest(
    CdmCertificateType cert_type,
    const std::string& cert_authority,
    const std::string& origin,
    CdmProvisioningRequest* request,
    std::string* default_url) {
  CdmEngine* cdm_engine = EnsureCdmForOrigin(origin);
  return cdm_engine->GetProvisioningRequest(cert_type, cert_authority, request,
                                            default_url);
}

CdmResponseType WvContentDecryptionModule::HandleProvisioningResponse(
    const std::string& origin,
    CdmProvisioningResponse& response,
    std::string* cert,
    std::string* wrapped_key) {
  CdmEngine* cdm_engine = EnsureCdmForOrigin(origin);
  return cdm_engine->HandleProvisioningResponse(response, cert, wrapped_key);
}

CdmResponseType WvContentDecryptionModule::Unprovision(
    CdmSecurityLevel level, const std::string& origin) {
  CdmEngine* cdm_engine = EnsureCdmForOrigin(origin);
  return cdm_engine->Unprovision(level);
}

CdmResponseType WvContentDecryptionModule::GetUsageInfo(
    const std::string& app_id, CdmUsageInfo* usage_info) {
  CdmEngine* cdm_engine = EnsureCdmForOrigin(EMPTY_ORIGIN);
  return cdm_engine->GetUsageInfo(app_id, usage_info);
}

CdmResponseType WvContentDecryptionModule::GetUsageInfo(
    const std::string& app_id,
    const CdmSecureStopId& ssid,
    CdmUsageInfo* usage_info) {
  CdmEngine* cdm_engine = EnsureCdmForOrigin(EMPTY_ORIGIN);
  return cdm_engine->GetUsageInfo(app_id, ssid, usage_info);
}

CdmResponseType WvContentDecryptionModule::ReleaseAllUsageInfo(
    const std::string& app_id) {
  CdmEngine* cdm_engine = EnsureCdmForOrigin(EMPTY_ORIGIN);
  return cdm_engine->ReleaseAllUsageInfo(app_id);
}

CdmResponseType WvContentDecryptionModule::ReleaseUsageInfo(
    const CdmUsageInfoReleaseMessage& message) {
  CdmEngine* cdm_engine = EnsureCdmForOrigin(EMPTY_ORIGIN);
  return cdm_engine->ReleaseUsageInfo(message);
}

CdmResponseType WvContentDecryptionModule::Decrypt(
    const CdmSessionId& session_id,
    bool validate_key_id,
    const CdmDecryptionParameters& parameters) {
  // First find the CdmEngine that has the given session_id.  If we are using
  // key sharing, the shared session will still be in the same CdmEngine.
  CdmEngine* cdm_engine = GetCdmForSessionId(session_id);
  if (!cdm_engine) return SESSION_NOT_FOUND_FOR_DECRYPT;

  CdmSessionId local_session_id = session_id;
  if (validate_key_id &&
      Properties::GetSessionSharingId(session_id) != 0) {
    bool status = cdm_engine->FindSessionForKey(*parameters.key_id,
                                                 &local_session_id);
    if (!status) {
      LOGE("WvContentDecryptionModule::Decrypt: unable to find session");
      return SESSION_NOT_FOUND_FOR_DECRYPT;
    }
  }
  return cdm_engine->Decrypt(local_session_id, parameters);
}

void WvContentDecryptionModule::NotifyResolution(const CdmSessionId& session_id,
                                                 uint32_t width,
                                                 uint32_t height) {
  CdmEngine* cdm_engine = GetCdmForSessionId(session_id);
  if (!cdm_engine) return;
  cdm_engine->NotifyResolution(session_id, width, height);
}

bool WvContentDecryptionModule::IsValidServiceCertificate(
    const std::string& certificate) {
  return ServiceCertificate::VerifySignedServiceCertificate(certificate) ==
         NO_ERROR;
}

WvContentDecryptionModule::CdmInfo::CdmInfo()
  : cdm_engine(new CdmEngine(&file_system)) {}

CdmEngine* WvContentDecryptionModule::EnsureCdmForOrigin(
    const std::string& origin) {
  AutoLock auto_lock(cdms_lock_);
  if (cdms_.find(origin) == cdms_.end()) {
    // Will create a new instance using the default constructor.
    cdms_[origin].file_system.SetOrigin(origin);
  }

  return cdms_[origin].cdm_engine.get();
}

CdmEngine* WvContentDecryptionModule::GetCdmForSessionId(
    const std::string& session_id) {
  // Use find to avoid creating empty entries when not found.
  auto it = cdm_by_session_id_.find(session_id);
  if (it == cdm_by_session_id_.end()) return NULL;
  return it->second;
}

void WvContentDecryptionModule::EnablePolicyTimer() {
  AutoLock auto_lock(policy_timer_lock_);
  if (!policy_timer_.IsRunning())
    policy_timer_.Start(this, kCdmPolicyTimerDurationSeconds);
}

void WvContentDecryptionModule::DisablePolicyTimer(bool force) {
  bool has_sessions = false;
  {
    AutoLock auto_lock(cdms_lock_);
    for (auto it = cdms_.begin(); it != cdms_.end();) {
      if (it->second.cdm_engine->SessionSize() != 0) {
        has_sessions = true;
        ++it;
      } else {
        // The CDM is no longer used for this origin, delete it.
        it = cdms_.erase(it);
      }
    }
  }

  AutoLock auto_lock(policy_timer_lock_);
  if ((!has_sessions || force) && policy_timer_.IsRunning())
    policy_timer_.Stop();
}

void WvContentDecryptionModule::OnTimerEvent() {
  AutoLock auto_lock(cdms_lock_);
  for (auto it = cdms_.begin(); it != cdms_.end(); ++it) {
    it->second.cdm_engine->OnTimerEvent();
  }
}

uint32_t WvContentDecryptionModule::GenerateSessionSharingId() {
  static int next_session_sharing_id = 0;
  return ++next_session_sharing_id;
}

}  // namespace wvcdm