Use Inheritence for OEMCrypto Mock Properties

Merge from Widevine repo of http://go/wvgerrit/24728

We use compiler options to set different properties in the oemcrypto
mock.  With this CL, we define a base class that has default
properties.  All other variants need only define the properties that
they change.

b/35141278
b/37353534

Change-Id: Id38ec5bf35dcd83cea9a066ebe201e6da7c1a2b0

libwvdrmengine/oemcrypto/mock/src/oemcrypto_engine_device_properties_cert.cpp

@@ -2,72 +2,33 @@
 //
 //  Mock implementation of OEMCrypto APIs
 //
-//  This file contains oemcrypto engine properties that would be for a
-//  level 2 device that does not have persistant storage or a keybox.
-//  Note: this is for illustration only.  Production devices are rarely level 2.
+//  This file contains oemcrypto engine properties that would be for a device
+//  that does not have persistant storage or a keybox.
+//
+//  Note: We also define it to be L2 for illustration only.  Production devices
+//  are rarely level 2.
 #include "oemcrypto_engine_mock.h"
 
 namespace wvoec_mock {
 
-// If config_local_display_only() returns true, we pretend we are using a
-// built-in display, instead of HDMI or WiFi output.
-bool CryptoEngine::config_local_display_only() {
-  return true;
-}
+class CertOnlyCryptoEngine : public CryptoEngine {
+ public:
+  explicit CertOnlyCryptoEngine(wvcdm::FileSystem* file_system)
+      : CryptoEngine(file_system) {}
 
-// A closed platform is permitted to use clear buffers.
-bool CryptoEngine::config_closed_platform() {
-  return false;
-}
+  bool config_local_display_only() { return true; }
 
-// Returns the HDCP version currently in use.
-OEMCrypto_HDCP_Capability CryptoEngine::config_current_hdcp_capability() {
-  return config_local_display_only() ? HDCP_NO_DIGITAL_OUTPUT : HDCP_V1;
-}
+  bool config_supports_usage_table() { return false; }
 
-// Returns the max HDCP version supported.
-OEMCrypto_HDCP_Capability CryptoEngine::config_maximum_hdcp_capability() {
-  return HDCP_NO_DIGITAL_OUTPUT;
-}
+  OEMCrypto_ProvisioningMethod config_provisioning_method() {
+    return OEMCrypto_DrmCertificate;
+  }
 
-// Returns true if the client supports persistent storage of
-// offline usage table information.
-bool CryptoEngine::config_supports_usage_table() {
-  return false;
-}
+  const char* config_security_level() { return "L2"; }
+};
 
-// Returns true if the client uses a keybox as the root of trust.
-bool CryptoEngine::config_supports_keybox() {
-  return false;
-}
-
-// This version uses a baked in DRM certificate.
-OEMCrypto_ProvisioningMethod CryptoEngine::config_provisioning_method() {
-  return OEMCrypto_DrmCertificate;
-}
-
-OEMCryptoResult CryptoEngine::get_oem_certificate(SessionContext *session,
-                                                  uint8_t *public_cert,
-                                                  size_t *public_cert_length) {
-  return OEMCrypto_ERROR_NOT_IMPLEMENTED;
-}
-
-// Returns true to indicate the client does support anti-rollback hardware.
-bool CryptoEngine::config_is_anti_rollback_hw_present() {
-  return false;
-}
-
-// Returns "L3" for a software only library.  L1 is for hardware protected keys
-// and data paths.  L2 is for hardware protected keys but no data path
-// protection.
-const char* CryptoEngine::config_security_level() {
-  return "L2";
-}
-
-// This should start at 0, and be incremented only when a security patch has
-// been applied to the device that fixes a security bug.
-uint8_t CryptoEngine::config_security_patch_level() {
-  return 0;
+CryptoEngine* CryptoEngine::MakeCryptoEngine(wvcdm::FileSystem* file_system) {
+  return new CertOnlyCryptoEngine(file_system);
 }
 
 }  // namespace wvoec_mock