1 files changed, 75 insertions, 0 deletions
diff --git a/common/libs/security/channel.h b/common/libs/security/channel.h
new file mode 100644
index 000000000..eb415e2a0
--- /dev/null
+++ b/common/libs/security/channel.h
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2023 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.
+ */
+
+#pragma once
+
+#include <memory>
+
+#include "common/libs/utils/result.h"
+
+namespace cuttlefish {
+namespace secure_env {
+
+/**
+ * RawMessage - Header and raw byte payload for a serialized
+ * secure env message.
+ *
+ * @command: the command.
+ * @is_response: flag to mark message as a request/response.
+ * @payload_size: amount of payload data we're going to transfer.
+ * @payload: start of the serialized command specific payload.
+ */
+struct RawMessage {
+  uint32_t command : 31;
+  bool is_response : 1;
+  uint32_t payload_size;
+  uint8_t payload[0];
+};
+
+/**
+ * A destroyer for RawMessage instances created with
+ * CreateMessage. Wipes memory from the RawMessage
+ * instances.
+ */
+class MessageDestroyer {
+ public:
+  void operator()(RawMessage* ptr);
+};
+
+/** An owning pointer for a RawMessage instance. */
+using ManagedMessage = std::unique_ptr<RawMessage, MessageDestroyer>;
+
+/**
+ * Allocates memory for a RawMessage carrying a message of size
+ * `payload_size`.
+ */
+Result<ManagedMessage> CreateMessage(uint32_t command, bool is_response, size_t payload_size);
+Result<ManagedMessage> CreateMessage(uint32_t command, size_t payload_size);
+
+/*
+ * Interface for communication channels that synchronously communicate
+ * HAL IPC/RPC calls.
+ */
+class Channel {
+ public:
+  virtual Result<void> SendRequest(RawMessage& message) = 0;
+  virtual Result<void> SendResponse(RawMessage& message) = 0;
+  virtual Result<ManagedMessage> ReceiveMessage() = 0;
+  virtual ~Channel() {}
+};
+
+}  // namespace secure_env
+}  // namespace cuttlefish
+\ No newline at end of file