1 /* 2 * Copyright 2020 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #pragma once 18 19 #include <cstddef> 20 #include <cstdint> 21 #include <memory> 22 23 #include <keymaster/android_keymaster_messages.h> 24 #include <keymaster/serializable.h> 25 26 #include "common/libs/fs/shared_fd.h" 27 28 namespace keymaster { 29 30 /** 31 * keymaster_message - Serial header for communicating with KM server 32 * @cmd: the command, one of AndroidKeymasterCommand. 33 * @payload: start of the serialized command specific payload 34 */ 35 struct keymaster_message { 36 AndroidKeymasterCommand cmd : 31; 37 bool is_response : 1; 38 std::uint32_t payload_size; 39 std::uint8_t payload[0]; 40 }; 41 42 } // namespace keymaster 43 44 namespace cuttlefish { 45 46 using keymaster::AndroidKeymasterCommand; 47 using keymaster::keymaster_message; 48 49 /** 50 * A destroyer for keymaster_message instances created with 51 * CreateKeymasterMessage. Wipes memory from the keymaster_message instances. 52 */ 53 class KeymasterCommandDestroyer { 54 public: 55 void operator()(keymaster_message* ptr); 56 }; 57 58 /** An owning pointer for a keymaster_message instance. */ 59 using ManagedKeymasterMessage = 60 std::unique_ptr<keymaster_message, KeymasterCommandDestroyer>; 61 62 /** 63 * Allocates memory for a keymaster_message carrying a message of size 64 * `payload_size`. 65 */ 66 ManagedKeymasterMessage CreateKeymasterMessage(AndroidKeymasterCommand command, 67 bool is_response, 68 std::size_t payload_size); 69 70 /* 71 * Interface for communication channels that synchronously communicate Keymaster 72 * IPC/RPC calls. Sends messages over a file descriptor. 73 */ 74 class KeymasterChannel { 75 public: 76 KeymasterChannel(SharedFD input, SharedFD output); 77 78 bool SendRequest(AndroidKeymasterCommand command, 79 const keymaster::Serializable& message); 80 bool SendResponse(AndroidKeymasterCommand command, 81 const keymaster::Serializable& message); 82 ManagedKeymasterMessage ReceiveMessage(); 83 private: 84 SharedFD input_; 85 SharedFD output_; 86 bool SendMessage(AndroidKeymasterCommand command, bool response, 87 const keymaster::Serializable& message); 88 }; 89 90 } // namespace cuttlefish 91