Add GoogleKeymaster. Very incomplete.

Change-Id: I53542c7132bd1a04afee93f3247b88ed7ed0bedc
diff --git a/google_softkeymaster.h b/google_softkeymaster.h
new file mode 100644
index 0000000..03df5b4
--- /dev/null
+++ b/google_softkeymaster.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef EXTERNAL_KEYMASTER_GOOGLE_SOFT_KEYMASTER_H_
+#define EXTERNAL_KEYMASTER_GOOGLE_SOFT_KEYMASTER_H_
+
+#include "google_keymaster.h"
+
+namespace keymaster {
+
+class GoogleSoftKeymaster : public GoogleKeymaster {
+  public:
+    bool is_enforced(keymaster_tag_t /* tag */) { return false; }
+    keymaster_key_origin_t origin() { return KM_ORIGIN_SOFTWARE; }
+
+  private:
+    static uint8_t master_key_[];
+
+    uint8_t* MasterKey() { return master_key_; }
+
+    size_t MasterKeyLength() { return 16; }
+
+    void GetNonce(uint8_t* nonce, size_t length) {
+        for (size_t i = 0; i < length; ++i)
+            nonce[i] = 0;
+    }
+};
+
+uint8_t GoogleSoftKeymaster::master_key_[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+
+}  // namespace
+
+#endif  // EXTERNAL_KEYMASTER_GOOGLE_SOFT_KEYMASTER_H_