Detect when unable to meet policy requirements

[ Merged of http://go/wvgerrit/39766 ]

The security level (software/hardware, decryption/decode)
in the policy that specified how the key was to be used was
not being respected for L3. Playback would either continue or
a vendor specific error would be thrown.

If the device cannot use the key as permitted by the policy
CryptoException#ERROR_INSUFFICIENT_OUTPUT_PROTECTION will be thrown.

Bug: 31913737
Bug: 31913439

Test: WV unit/integration tests
Test: Playback using playmovies and netflix. Cast playback using
      playmovies.

Change-Id: If25735ab0f789108431115623cb236687c5ef818

libwvdrmengine/cdm/core/include/policy_engine.h

@@ -39,6 +39,10 @@ class PolicyEngine {
   // out why a key is not usable.
   virtual CdmKeyStatus GetKeyStatus(const KeyId& key_id);
 
+  // Verifies whether the policy allows use of the specified key of
+  // a given security level for content decryption.
+  virtual bool CanUseKey(const KeyId& key_id, CdmSecurityLevel security_level);
+
   // OnTimerEvent is called when a timer fires. It notifies the Policy Engine
   // that the timer has fired and dispatches the relevant events through
   // |event_listener_|.

libwvdrmengine/cdm/core/include/wv_cdm_types.h

@@ -428,6 +428,16 @@ struct CdmUsageEntryInfo {
   }
 };
 
+enum CdmKeySecurityLevel {
+  kKeySecurityLevelUnset,
+  kSoftwareSecureCrypto,
+  kSoftwareSecureDecode,
+  kHardwareSecureCrypto,
+  kHardwareSecureDecode,
+  kHardwareSecureAll,
+  kKeySecurityLevelUnknown,
+};
+
 class CdmKeyAllowedUsage {
  public:
   CdmKeyAllowedUsage() {
@@ -444,6 +454,7 @@ class CdmKeyAllowedUsage {
     generic_decrypt = false;
     generic_sign = false;
     generic_verify = false;
+    key_security_level_ = kKeySecurityLevelUnset;
     valid_ = false;
   }
 
@@ -454,7 +465,8 @@ class CdmKeyAllowedUsage {
         generic_encrypt != other.generic_encrypt ||
         generic_decrypt != other.generic_decrypt ||
         generic_sign != other.generic_sign ||
-        generic_verify != other.generic_verify) {
+        generic_verify != other.generic_verify ||
+        key_security_level_ != other.key_security_level_) {
       return false;
     }
     return true;
@@ -466,6 +478,7 @@ class CdmKeyAllowedUsage {
   bool generic_decrypt;
   bool generic_sign;
   bool generic_verify;
+  CdmKeySecurityLevel key_security_level_;
 
  private:
   bool valid_;