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 #include "keymaster_channel.h"
18
19 #include <android-base/logging.h>
20 #include "keymaster/android_keymaster_utils.h"
21
22 #include "common/libs/fs/shared_buf.h"
23
24 namespace cuttlefish {
25
CreateKeymasterMessage(AndroidKeymasterCommand command,bool is_response,size_t payload_size)26 ManagedKeymasterMessage CreateKeymasterMessage(
27 AndroidKeymasterCommand command, bool is_response, size_t payload_size) {
28 auto memory = new uint8_t[payload_size + sizeof(keymaster_message)];
29 auto message = reinterpret_cast<keymaster_message*>(memory);
30 message->cmd = command;
31 message->is_response = is_response;
32 message->payload_size = payload_size;
33 return ManagedKeymasterMessage(message);
34 }
35
operator ()(keymaster_message * ptr)36 void KeymasterCommandDestroyer::operator()(keymaster_message* ptr) {
37 {
38 keymaster::Eraser(ptr, sizeof(keymaster_message) + ptr->payload_size);
39 }
40 delete reinterpret_cast<uint8_t*>(ptr);
41 }
42
KeymasterChannel(SharedFD input,SharedFD output)43 KeymasterChannel::KeymasterChannel(SharedFD input, SharedFD output)
44 : input_(input), output_(output) {
45 }
46
SendRequest(AndroidKeymasterCommand command,const keymaster::Serializable & message)47 bool KeymasterChannel::SendRequest(
48 AndroidKeymasterCommand command, const keymaster::Serializable& message) {
49 return SendMessage(command, false, message);
50 }
51
SendResponse(AndroidKeymasterCommand command,const keymaster::Serializable & message)52 bool KeymasterChannel::SendResponse(
53 AndroidKeymasterCommand command, const keymaster::Serializable& message) {
54 return SendMessage(command, true, message);
55 }
56
SendMessage(AndroidKeymasterCommand command,bool is_response,const keymaster::Serializable & message)57 bool KeymasterChannel::SendMessage(
58 AndroidKeymasterCommand command,
59 bool is_response,
60 const keymaster::Serializable& message) {
61 auto payload_size = message.SerializedSize();
62 LOG(VERBOSE) << "Sending message with id: " << command << " and size "
63 << payload_size;
64 auto to_send = CreateKeymasterMessage(command, is_response, payload_size);
65 message.Serialize(to_send->payload, to_send->payload + payload_size);
66 auto write_size = payload_size + sizeof(keymaster_message);
67 auto to_send_bytes = reinterpret_cast<const char*>(to_send.get());
68 auto written = WriteAll(output_, to_send_bytes, write_size);
69 if (written != write_size) {
70 LOG(ERROR) << "Could not write Keymaster Message: " << output_->StrError();
71 }
72 return written == write_size;
73 }
74
ReceiveMessage()75 ManagedKeymasterMessage KeymasterChannel::ReceiveMessage() {
76 struct keymaster_message message_header;
77 auto read = ReadExactBinary(input_, &message_header);
78 if (read != sizeof(keymaster_message)) {
79 LOG(ERROR) << "Expected " << sizeof(keymaster_message) << ", received "
80 << read;
81 LOG(ERROR) << "Could not read Keymaster Message: " << input_->StrError();
82 return {};
83 }
84 LOG(VERBOSE) << "Received message with id: " << message_header.cmd
85 << " and size " << message_header.payload_size;
86 auto message = CreateKeymasterMessage(message_header.cmd,
87 message_header.is_response,
88 message_header.payload_size);
89 auto message_bytes = reinterpret_cast<char*>(message->payload);
90 read = ReadExact(input_, message_bytes, message->payload_size);
91 if (read != message->payload_size) {
92 LOG(ERROR) << "Could not read Keymaster Message: " << input_->StrError();
93 return {};
94 }
95 return message;
96 }
97
98 }
99