L1 System Lowered to L3 Still Requires Secure Decoders

Merge of https://widevine-internal-review.googlesource.com/#/c/8263
from the Widevine repo.

Changes the behavior of requiresSecureDecoderComponent() to query the
session for whether a lowered security level has been requested
before querying the system to see what its default security level is.

As part of this, we added a new QuerySessionStatus() method to the
CDM that gets status info on a session-specific level, such as the
effective security level of a session.

Bug: 11428937
Change-Id: I5549a2fdd400cc87f567d27fcf74c473451093d6

libwvdrmengine/cdm/core/include/cdm_engine.h

@@ -65,6 +65,10 @@ class CdmEngine : public TimerHandler {
   // Query system information
   virtual CdmResponseType QueryStatus(CdmQueryMap* info);
 
+  // Query session information
+  virtual CdmResponseType QuerySessionStatus(const CdmSessionId& session_id,
+                                             CdmQueryMap* key_info);
+
   // Query license information
   virtual CdmResponseType QueryKeyStatus(const CdmSessionId& session_id,
                                          CdmQueryMap* key_info);

libwvdrmengine/cdm/core/include/cdm_session.h

@@ -49,6 +49,9 @@ class CdmSession {
   // CancelKeyRequest() - Cancel session.
   CdmResponseType CancelKeyRequest();
 
+  // Query session status
+  CdmResponseType QueryStatus(CdmQueryMap* key_info);
+
   // Query license information
   CdmResponseType QueryKeyStatus(CdmQueryMap* key_info);
 

libwvdrmengine/cdm/core/src/cdm_engine.cpp

@@ -401,6 +401,18 @@ CdmResponseType CdmEngine::QueryStatus(CdmQueryMap* key_info) {
   return NO_ERROR;
 }
 
+CdmResponseType CdmEngine::QuerySessionStatus(const CdmSessionId& session_id,
+                                              CdmQueryMap* key_info) {
+  LOGI("CdmEngine::QuerySessionStatus");
+  CdmSessionMap::iterator iter = sessions_.find(session_id);
+  if (iter == sessions_.end()) {
+    LOGE("CdmEngine::QuerySessionStatus: session_id not found = %s",
+         session_id.c_str());
+    return KEY_ERROR;
+  }
+  return iter->second->QueryStatus(key_info);
+}
+
 CdmResponseType CdmEngine::QueryKeyStatus(
     const CdmSessionId& session_id,
     CdmQueryMap* key_info) {

libwvdrmengine/cdm/core/src/cdm_session.cpp

@@ -239,6 +239,37 @@ CdmResponseType CdmSession::AddKey(const CdmKeyResponse& key_response,
   }
 }
 
+CdmResponseType CdmSession::QueryStatus(CdmQueryMap* key_info) {
+  if (crypto_session_.get() == NULL) {
+    LOGW("CdmSession::QueryStatus: Invalid crypto session");
+    return UNKNOWN_ERROR;
+  }
+
+  if (!crypto_session_->IsOpen()) {
+    LOGW("CdmSession::QueryStatus: Crypto session not open");
+    return UNKNOWN_ERROR;
+  }
+
+  switch (crypto_session_->GetSecurityLevel()) {
+    case kSecurityLevelL1:
+      (*key_info)[QUERY_KEY_SECURITY_LEVEL] = QUERY_VALUE_SECURITY_LEVEL_L1;
+      break;
+    case kSecurityLevelL2:
+      (*key_info)[QUERY_KEY_SECURITY_LEVEL] = QUERY_VALUE_SECURITY_LEVEL_L2;
+      break;
+    case kSecurityLevelL3:
+      (*key_info)[QUERY_KEY_SECURITY_LEVEL] = QUERY_VALUE_SECURITY_LEVEL_L3;
+      break;
+    case kSecurityLevelUninitialized:
+    case kSecurityLevelUnknown:
+      (*key_info)[QUERY_KEY_SECURITY_LEVEL] = QUERY_VALUE_SECURITY_LEVEL_Unknown;
+      break;
+    default:
+      return KEY_ERROR;
+  }
+  return NO_ERROR;
+}
+
 CdmResponseType CdmSession::QueryKeyStatus(CdmQueryMap* key_info) {
   return policy_engine_.Query(key_info);
 }