Certificate provisioning verification

bug: 8620943

This is a merge of changes made to the Widevine CDM
repository during certificate provisioning verification.

The following changes are included:

Fixes for certificate based licensing
https://widevine-internal-review.googlesource.com/#/c/5162/

Base64 encode and decode now handles non-multiple of 24-bits input
https://widevine-internal-review.googlesource.com/#/c/4981/

Fixed issues with device provisioning response handling
https://widevine-internal-review.googlesource.com/#/c/5153/

Persistent storage to support device certificates
https://widevine-internal-review.googlesource.com/#/c/5161/

Enable loading of certificates
https://widevine-internal-review.googlesource.com/#/c/5172/

Provide license server url
https://widevine-internal-review.googlesource.com/#/c/5173/

Change-Id: I0c032c1ae0055dcc1a7a77ad4b0ea0898030dc7d

libwvdrmengine/cdm/core/include/device_files.h

@@ -0,0 +1,33 @@
+// Copyright 2013 Google Inc. All Rights Reserved.
+//
+#ifndef CDM_BASE_DEVICE_FILES_H_
+#define CDM_BASE_DEVICE_FILES_H_
+
+#include "wv_cdm_types.h"
+
+namespace wvcdm {
+
+class DeviceFiles {
+ public:
+  static bool StoreCertificate(const std::string& certificate,
+                               const std::string& wrapped_private_key);
+  static bool RetrieveCertificate(std::string* certificate,
+                                  std::string* wrapped_private_key);
+
+  static std::string GetPath(const char* dir, const char * filename);
+  static const char* kBasePath;
+  static const char* kIdmPath;
+  static const char* kCencPath;
+  static const char* kDeviceCertificateFileName;
+
+ private:
+  static bool Hash(const std::string& data, std::string* hash);
+  static bool StoreFile(const char* name, const std::string& data);
+  static bool RetrieveFile(const char* name, std::string* data);
+
+  CORE_DISALLOW_COPY_AND_ASSIGN(DeviceFiles);
+};  // namespace wvcdm
+
+}
+
+#endif  // CDM_BASE_DEVICE_FILES_H_