Export media_cas_packager_sdk

common/signing_key_util.cc

@@ -0,0 +1,44 @@
+////////////////////////////////////////////////////////////////////////////////
+// Copyright 2016 Google LLC.
+//
+// This software is licensed under the terms defined in the Widevine Master
+// License Agreement. For a copy of this agreement, please contact
+// widevine-licensing@google.com.
+////////////////////////////////////////////////////////////////////////////////
+
+#include "common/signing_key_util.h"
+
+#include "glog/logging.h"
+#include "common/crypto_util.h"
+#include "protos/public/license_protocol.pb.h"
+
+namespace widevine {
+
+using crypto_util::kSigningKeySizeBits;
+
+uint32_t SigningKeyMaterialSize(ProtocolVersion protocol_version) {
+  if (protocol_version <= VERSION_2_0) {
+    return kSigningKeySizeBits;
+  } else {
+    return kSigningKeySizeBits * 2;
+  }
+}
+
+using crypto_util::kSigningKeySizeBytes;
+std::string GetClientSigningKey(const std::string& derived_key,
+                           ProtocolVersion protocol_version) {
+  if (protocol_version == VERSION_2_0) {
+    DCHECK(derived_key.size() >= kSigningKeySizeBytes);
+    return derived_key.substr(0, kSigningKeySizeBytes);
+  } else {
+    DCHECK(derived_key.size() >= kSigningKeySizeBytes * 2);
+    return derived_key.substr(kSigningKeySizeBytes, kSigningKeySizeBytes);
+  }
+}
+
+std::string GetServerSigningKey(const std::string& derived_key) {
+  DCHECK(derived_key.size() >= kSigningKeySizeBytes);
+  return derived_key.substr(0, kSigningKeySizeBytes);
+}
+
+}  // namespace widevine