1 /*
2 * Copyright (C) 2021 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 //! A tool to verify a CompOS signature. It starts a CompOS VM as part of this to retrieve the
18 //! public key. The tool is intended to be run by odsign during boot.
19
20 use android_logger::LogId;
21 use anyhow::{bail, Context, Result};
22 use compos_aidl_interface::binder::ProcessState;
23 use compos_common::compos_client::{VmInstance, VmParameters};
24 use compos_common::odrefresh::{
25 CURRENT_ARTIFACTS_SUBDIR, ODREFRESH_OUTPUT_ROOT_DIR, PENDING_ARTIFACTS_SUBDIR,
26 TEST_ARTIFACTS_SUBDIR,
27 };
28 use compos_common::{
29 COMPOS_DATA_ROOT, CURRENT_INSTANCE_DIR, IDSIG_FILE, IDSIG_MANIFEST_APK_FILE,
30 INSTANCE_IMAGE_FILE, TEST_INSTANCE_DIR,
31 };
32 use log::error;
33 use std::fs::File;
34 use std::io::Read;
35 use std::panic;
36 use std::path::Path;
37
38 const MAX_FILE_SIZE_BYTES: u64 = 100 * 1024;
39
main()40 fn main() {
41 android_logger::init_once(
42 android_logger::Config::default()
43 .with_tag("compos_verify")
44 .with_min_level(log::Level::Info)
45 .with_log_id(LogId::System), // Needed to log successfully early in boot
46 );
47
48 // Redirect panic messages to logcat.
49 panic::set_hook(Box::new(|panic_info| {
50 error!("{}", panic_info);
51 }));
52
53 if let Err(e) = try_main() {
54 error!("{:?}", e);
55 std::process::exit(1)
56 }
57 }
58
try_main() -> Result<()>59 fn try_main() -> Result<()> {
60 let matches = clap::App::new("compos_verify")
61 .arg(
62 clap::Arg::with_name("instance")
63 .long("instance")
64 .takes_value(true)
65 .required(true)
66 .possible_values(&["current", "pending", "test"]),
67 )
68 .arg(clap::Arg::with_name("debug").long("debug"))
69 .get_matches();
70
71 let debug_mode = matches.is_present("debug");
72 let (instance_dir, artifacts_dir) = match matches.value_of("instance").unwrap() {
73 "current" => (CURRENT_INSTANCE_DIR, CURRENT_ARTIFACTS_SUBDIR),
74 "pending" => (CURRENT_INSTANCE_DIR, PENDING_ARTIFACTS_SUBDIR),
75 "test" => (TEST_INSTANCE_DIR, TEST_ARTIFACTS_SUBDIR),
76 _ => unreachable!("Unexpected instance name"),
77 };
78
79 let instance_dir = Path::new(COMPOS_DATA_ROOT).join(instance_dir);
80 let artifacts_dir = Path::new(ODREFRESH_OUTPUT_ROOT_DIR).join(artifacts_dir);
81
82 if !instance_dir.is_dir() {
83 bail!("{:?} is not a directory", instance_dir);
84 }
85
86 let instance_image = instance_dir.join(INSTANCE_IMAGE_FILE);
87 let idsig = instance_dir.join(IDSIG_FILE);
88 let idsig_manifest_apk = instance_dir.join(IDSIG_MANIFEST_APK_FILE);
89
90 let instance_image = File::open(instance_image).context("Failed to open instance image")?;
91
92 let info = artifacts_dir.join("compos.info");
93 let signature = artifacts_dir.join("compos.info.signature");
94
95 let info = read_small_file(&info).context("Failed to read compos.info")?;
96 let signature = read_small_file(&signature).context("Failed to read compos.info signature")?;
97
98 // We need to start the thread pool to be able to receive Binder callbacks
99 ProcessState::start_thread_pool();
100
101 let virtualization_service = VmInstance::connect_to_virtualization_service()?;
102 let vm_instance = VmInstance::start(
103 &*virtualization_service,
104 instance_image,
105 &idsig,
106 &idsig_manifest_apk,
107 &VmParameters { debug_mode, never_log: !debug_mode, ..Default::default() },
108 )?;
109 let service = vm_instance.get_service()?;
110
111 let public_key = service.getPublicKey().context("Getting public key")?;
112
113 if !compos_verify_native::verify(&public_key, &signature, &info) {
114 bail!("Signature verification failed");
115 }
116
117 Ok(())
118 }
119
read_small_file(file: &Path) -> Result<Vec<u8>>120 fn read_small_file(file: &Path) -> Result<Vec<u8>> {
121 let mut file = File::open(file)?;
122 if file.metadata()?.len() > MAX_FILE_SIZE_BYTES {
123 bail!("File is too big");
124 }
125 let mut data = Vec::new();
126 file.read_to_end(&mut data)?;
127 Ok(data)
128 }
129