V18.4.0 CAS plugin

Note that this version does not have Widevine Provisioning 4.0 support.
It is only suitable for device upgrades. A new patch with provisioning
4.0 support will be made later.

plugin/include/cas_media_id.h

@@ -0,0 +1,25 @@
+#ifndef CAS_MEDIA_ID_H
+#define CAS_MEDIA_ID_H
+
+namespace wvcas {
+
+class CasMediaId {
+ protected:
+  CasMediaId() {}
+
+ public:
+  CasMediaId(const CasMediaId&) = delete;
+  CasMediaId& operator=(const CasMediaId&) = delete;
+  virtual ~CasMediaId() {}
+  static std::unique_ptr<CasMediaId> create();
+  virtual CasStatus initialize(const std::string& init_data) = 0;
+  virtual const std::string content_id() = 0;
+  virtual const std::string provider_id() = 0;
+  virtual bool is_entitlement_rotation_enabled() { return false; }
+  virtual uint32_t entitlement_period_index() = 0;
+  virtual std::string get_init_data() = 0;
+};
+
+}  // namespace wvcas
+
+#endif  // CAS_MEDIA_ID_H