Reset crypto session pointers on RemoveKeys.

[ Merge of http://go/wvgerrit/189590 ]
[ Cherry-pick of http://ag/26541307 ]

The CDM session shares its CryptoSession instance with a few additional
member objects (CdmLicense and PolicyEngine).  When the CDM session's
crypto session is reset, it must also reset the CdmLicense and
PolicyEngine otherwise, a potential stale pointer reference may occur.

Test: request_license_test on Oriole
Test: run_x86_64_tests
Bug: 311239278
Change-Id: Ie175513ae652dcd96e12e5e1def574a8a56d5863

libwvdrmengine/cdm/core/include/cdm_session.h

@@ -265,6 +265,8 @@ class CdmSession {
 
   bool HasRootOfTrustBeenRenewed();
 
+  CdmResponseType ResetCryptoSession();
+
   // 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);
@@ -340,8 +342,9 @@ class CdmSession {
   bool has_license_been_loaded_ = false;
   bool has_license_been_restored_ = false;
 
-  bool mock_license_parser_in_use_;
-  bool mock_policy_engine_in_use_;
+  bool mock_crypto_session_in_use_ = false;
+  bool mock_license_parser_in_use_ = false;
+  bool mock_policy_engine_in_use_ = false;
 
   CORE_DISALLOW_COPY_AND_ASSIGN(CdmSession);
 };

libwvdrmengine/cdm/core/include/license.h

@@ -90,6 +90,15 @@ class CdmLicense {
       const CdmKeyResponse& license_response,
       std::string* provider_session_token);
 
+  // Testing only.  Caller retains ownership of pointers.
+  void set_crypto_session(CryptoSession* crypto_session) {
+    crypto_session_ = crypto_session;
+  }
+
+  void set_policy_engine(PolicyEngine* policy_engine) {
+    policy_engine_ = policy_engine;
+  }
+
  private:
   CdmResponseType HandleKeyErrorResponse(
       const video_widevine::SignedMessage& signed_message);
@@ -131,8 +140,8 @@ class CdmLicense {
   bool SetTypeAndId(CdmLicenseType license_type, const std::string& request_id,
                     T* content_id);
 
-  CryptoSession* crypto_session_;
-  PolicyEngine* policy_engine_;
+  CryptoSession* crypto_session_ = nullptr;
+  PolicyEngine* policy_engine_ = nullptr;
   std::string server_url_;
   std::string client_token_;
   const CdmSessionId session_id_;

libwvdrmengine/cdm/core/include/policy_engine.h

@@ -106,6 +106,8 @@ class PolicyEngine {
 
   virtual const LicenseIdentification& license_id() { return license_id_; }
 
+  WvCdmEventListener* event_listener() { return event_listener_; }
+
   bool GetSecondsSinceStarted(int64_t* seconds_since_started);
   bool GetSecondsSinceLastPlayed(int64_t* seconds_since_started);
 
@@ -131,6 +133,11 @@ class PolicyEngine {
     return license_keys_->MeetsConstraints(key_id);
   }
 
+  // Testing only.  Caller retains ownership.
+  void set_crypto_session(CryptoSession* crypto_session) {
+    crypto_session_ = crypto_session;
+  }
+
  private:
   friend class PolicyEngineTest;
   friend class PolicyEngineConstraintsTest;

libwvdrmengine/cdm/core/include/wv_cdm_types.h

@@ -945,6 +945,8 @@ const char* IdToString(const std::string& id);
 // provided as string pointers.
 const char* IdPtrToString(const std::string* id);
 
+const char* BoolToString(bool value);
+
 // Logging utilities for OEMCrypto types.
 const char* OemCryptoResultToString(OEMCryptoResult result);
 }  // namespace wvcdm