Exposing the Cast Signing Algorithm

1. Exposing the Cast Signing Algorithm in cdm core.
2. Update core Cast tests to use new core CDM Cast signing API.

Bug: 279671867
Bug: 279672538
Change-Id: Ia73c4b5e6dd61edf790bca97a321881d310e7a99

libwvdrmengine/cdm/core/include/cdm_engine.h

@@ -388,6 +388,13 @@ class CdmEngine {
   virtual void SetDefaultOtaKeyboxFallbackDurationRules();
   virtual void SetFastOtaKeyboxFallbackDurationRules();
 
+  // A signing method specifically used by Cast.
+  // This method should not be used otherwise.
+  virtual CdmResponseType SignRSA(const std::string& wrapped_key,
+                                  const std::string& message,
+                                  std::string* signature,
+                                  RSA_Padding_Scheme padding_scheme);
+
  protected:
   friend class CdmEngineFactory;
 

libwvdrmengine/cdm/core/include/cdm_session.h

@@ -219,6 +219,13 @@ class CdmSession {
 
   virtual metrics::SessionMetrics* GetMetrics() { return metrics_.get(); }
 
+  virtual CdmResponseType LoadCastPrivateKey(
+      const CryptoWrappedKey& private_key);
+
+  virtual CdmResponseType GenerateRSASignature(const std::string& message,
+                                               std::string* signature,
+                                               RSA_Padding_Scheme scheme);
+
  private:
   friend class CdmSessionTest;
 

libwvdrmengine/cdm/core/include/crypto_session.h

@@ -347,6 +347,11 @@ class CryptoSession {
   virtual CdmResponseType LoadOtaProvisioning(bool use_test_key,
                                               const std::string& response);
 
+  // Cast specific generate signature method.
+  virtual CdmResponseType GenerateRsaSignature(const std::string& message,
+                                               std::string* signature,
+                                               RSA_Padding_Scheme scheme);
+
  protected:
   // Creates an instance of CryptoSession with the given |crypto_metrics|.
   // |crypto_metrics| is owned by the caller, must NOT be null, and must
@@ -385,8 +390,6 @@ class CryptoSession {
   // Note:  This function will lock the global static field lock in write mode.
   bool SetUpUsageTable(RequestedSecurityLevel requested_security_level);
 
-  CdmResponseType GenerateRsaSignature(const std::string& message,
-                                       std::string* signature);
   size_t GetMaxSubsampleRegionSize();
 
   bool SetDestinationBufferType();

libwvdrmengine/cdm/core/include/wv_cdm_types.h

@@ -460,6 +460,7 @@ enum CdmResponseEnum : int32_t {
   STORE_ATSC_LICENSE_DEVICE_FILES_INIT_ERROR = 394,
   STORE_ATSC_LICENSE_ERROR = 395,
   SESSION_NOT_FOUND_GENERIC_CRYPTO = 396,
+  SESSION_NOT_FOUND_24 = 397,
   // Don't forget to add new values to
   //  * core/src/wv_cdm_types.cpp
   //  * android/include/mapErrors-inl.h