Alan Stokes | 6b2d0a8 | 2021-09-29 11:30:39 +0100 | [diff] [blame] | 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 | //! Responsible for validating and starting an existing instance of the CompOS VM, or creating and |
| 18 | //! starting a new instance if necessary. |
| 19 | |
| 20 | use android_system_virtualizationservice::aidl::android::system::virtualizationservice::{ |
| 21 | IVirtualizationService::IVirtualizationService, PartitionType::PartitionType, |
| 22 | }; |
| 23 | use anyhow::{bail, Context, Result}; |
| 24 | use compos_aidl_interface::aidl::com::android::compos::ICompOsService::ICompOsService; |
| 25 | use compos_aidl_interface::binder::{ParcelFileDescriptor, Strong}; |
| 26 | use compos_common::compos_client::VmInstance; |
| 27 | use compos_common::{ |
| 28 | COMPOS_DATA_ROOT, INSTANCE_IMAGE_FILE, PRIVATE_KEY_BLOB_FILE, PUBLIC_KEY_FILE, |
| 29 | }; |
| 30 | use log::{info, warn}; |
Victor Hsieh | 18775b1 | 2021-10-12 17:42:48 -0700 | [diff] [blame^] | 31 | use std::env; |
Alan Stokes | 6b2d0a8 | 2021-09-29 11:30:39 +0100 | [diff] [blame] | 32 | use std::fs; |
| 33 | use std::path::{Path, PathBuf}; |
| 34 | |
| 35 | pub struct CompOsInstance { |
| 36 | #[allow(dead_code)] // Keeps VirtualizationService & the VM alive |
| 37 | vm_instance: VmInstance, |
| 38 | service: Strong<dyn ICompOsService>, |
| 39 | } |
| 40 | |
| 41 | impl CompOsInstance { |
| 42 | pub fn get_service(&self) -> Strong<dyn ICompOsService> { |
| 43 | self.service.clone() |
| 44 | } |
| 45 | } |
| 46 | |
| 47 | pub struct InstanceStarter { |
| 48 | instance_name: String, |
| 49 | instance_root: PathBuf, |
| 50 | instance_image: PathBuf, |
| 51 | key_blob: PathBuf, |
| 52 | public_key: PathBuf, |
| 53 | } |
| 54 | |
| 55 | impl InstanceStarter { |
| 56 | pub fn new(instance_name: &str) -> Self { |
| 57 | let instance_root = Path::new(COMPOS_DATA_ROOT).join(instance_name); |
| 58 | let instant_root_path = instance_root.as_path(); |
| 59 | let instance_image = instant_root_path.join(INSTANCE_IMAGE_FILE); |
| 60 | let key_blob = instant_root_path.join(PRIVATE_KEY_BLOB_FILE); |
| 61 | let public_key = instant_root_path.join(PUBLIC_KEY_FILE); |
| 62 | Self { |
| 63 | instance_name: instance_name.to_owned(), |
| 64 | instance_root, |
| 65 | instance_image, |
| 66 | key_blob, |
| 67 | public_key, |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | pub fn create_or_start_instance( |
| 72 | &self, |
| 73 | service: &dyn IVirtualizationService, |
| 74 | ) -> Result<CompOsInstance> { |
| 75 | let compos_instance = self.start_existing_instance(); |
| 76 | match compos_instance { |
| 77 | Ok(_) => return compos_instance, |
Alan Stokes | 14f0739 | 2021-09-27 14:03:31 +0100 | [diff] [blame] | 78 | Err(e) => warn!("Failed to start: {}", e), |
Alan Stokes | 6b2d0a8 | 2021-09-29 11:30:39 +0100 | [diff] [blame] | 79 | } |
| 80 | |
| 81 | self.start_new_instance(service) |
| 82 | } |
| 83 | |
| 84 | fn start_existing_instance(&self) -> Result<CompOsInstance> { |
| 85 | // No point even trying if the files we need aren't there. |
| 86 | self.check_files_exist()?; |
| 87 | |
Alan Stokes | 14f0739 | 2021-09-27 14:03:31 +0100 | [diff] [blame] | 88 | info!("Starting {} CompOs instance", self.instance_name); |
| 89 | |
Alan Stokes | 6b2d0a8 | 2021-09-29 11:30:39 +0100 | [diff] [blame] | 90 | let key_blob = fs::read(&self.key_blob).context("Reading private key blob")?; |
| 91 | let public_key = fs::read(&self.public_key).context("Reading public key")?; |
| 92 | |
Alan Stokes | 16e027f | 2021-10-04 17:57:31 +0100 | [diff] [blame] | 93 | let compos_instance = self.start_vm()?; |
| 94 | let service = &compos_instance.service; |
Alan Stokes | 6b2d0a8 | 2021-09-29 11:30:39 +0100 | [diff] [blame] | 95 | |
| 96 | if !service.verifySigningKey(&key_blob, &public_key).context("Verifying key pair")? { |
| 97 | bail!("Key pair invalid"); |
| 98 | } |
| 99 | |
| 100 | // If we get this far then the instance image is valid in the current context (e.g. the |
| 101 | // current set of APEXes) and the key blob can be successfully decrypted by the VM. So the |
| 102 | // files have not been tampered with and we're good to go. |
| 103 | |
Victor Hsieh | 18775b1 | 2021-10-12 17:42:48 -0700 | [diff] [blame^] | 104 | Self::initialize_service(service, &key_blob)?; |
Alan Stokes | 6b2d0a8 | 2021-09-29 11:30:39 +0100 | [diff] [blame] | 105 | |
Alan Stokes | 16e027f | 2021-10-04 17:57:31 +0100 | [diff] [blame] | 106 | Ok(compos_instance) |
Alan Stokes | 6b2d0a8 | 2021-09-29 11:30:39 +0100 | [diff] [blame] | 107 | } |
| 108 | |
| 109 | fn start_new_instance( |
| 110 | &self, |
| 111 | virtualization_service: &dyn IVirtualizationService, |
| 112 | ) -> Result<CompOsInstance> { |
| 113 | info!("Creating {} CompOs instance", self.instance_name); |
| 114 | |
| 115 | // Ignore failure here - the directory may already exist. |
| 116 | let _ = fs::create_dir(&self.instance_root); |
| 117 | |
| 118 | self.create_instance_image(virtualization_service)?; |
| 119 | |
Alan Stokes | 16e027f | 2021-10-04 17:57:31 +0100 | [diff] [blame] | 120 | let compos_instance = self.start_vm()?; |
| 121 | let service = &compos_instance.service; |
Alan Stokes | 6b2d0a8 | 2021-09-29 11:30:39 +0100 | [diff] [blame] | 122 | |
| 123 | let key_data = service.generateSigningKey().context("Generating signing key")?; |
| 124 | fs::write(&self.key_blob, &key_data.keyBlob).context("Writing key blob")?; |
Alan Stokes | 14f0739 | 2021-09-27 14:03:31 +0100 | [diff] [blame] | 125 | |
| 126 | let key_result = composd_native::extract_rsa_public_key(&key_data.certificate); |
| 127 | let rsa_public_key = key_result.key; |
| 128 | if rsa_public_key.is_empty() { |
| 129 | bail!("Failed to extract public key from certificate: {}", key_result.error); |
| 130 | } |
| 131 | fs::write(&self.public_key, &rsa_public_key).context("Writing public key")?; |
Alan Stokes | 6b2d0a8 | 2021-09-29 11:30:39 +0100 | [diff] [blame] | 132 | |
Victor Hsieh | 18775b1 | 2021-10-12 17:42:48 -0700 | [diff] [blame^] | 133 | // Unlike when starting an existing instance, we don't need to verify the key, since we |
| 134 | // just generated it and have it in memory. |
Alan Stokes | 6b2d0a8 | 2021-09-29 11:30:39 +0100 | [diff] [blame] | 135 | |
Victor Hsieh | 18775b1 | 2021-10-12 17:42:48 -0700 | [diff] [blame^] | 136 | Self::initialize_service(service, &key_data.keyBlob)?; |
Alan Stokes | 6b2d0a8 | 2021-09-29 11:30:39 +0100 | [diff] [blame] | 137 | |
Alan Stokes | 16e027f | 2021-10-04 17:57:31 +0100 | [diff] [blame] | 138 | Ok(compos_instance) |
| 139 | } |
| 140 | |
Victor Hsieh | 18775b1 | 2021-10-12 17:42:48 -0700 | [diff] [blame^] | 141 | fn initialize_service(service: &Strong<dyn ICompOsService>, key_blob: &[u8]) -> Result<()> { |
| 142 | // Key blob is assumed to be verified/trusted. |
| 143 | service.initializeSigningKey(key_blob).context("Loading signing key")?; |
| 144 | |
| 145 | // TODO(198211396): Implement correctly. |
| 146 | service |
| 147 | .initializeClasspaths(&env::var("BOOTCLASSPATH")?, &env::var("DEX2OATBOOTCLASSPATH")?) |
| 148 | .context("Initializing *CLASSPATH")?; |
| 149 | Ok(()) |
| 150 | } |
| 151 | |
Alan Stokes | 16e027f | 2021-10-04 17:57:31 +0100 | [diff] [blame] | 152 | fn start_vm(&self) -> Result<CompOsInstance> { |
| 153 | let instance_image = fs::OpenOptions::new() |
| 154 | .read(true) |
| 155 | .write(true) |
| 156 | .open(&self.instance_image) |
| 157 | .context("Failed to open instance image")?; |
| 158 | let vm_instance = VmInstance::start(instance_image).context("Starting VM")?; |
| 159 | let service = vm_instance.get_service().context("Connecting to CompOS")?; |
Alan Stokes | 6b2d0a8 | 2021-09-29 11:30:39 +0100 | [diff] [blame] | 160 | Ok(CompOsInstance { vm_instance, service }) |
| 161 | } |
| 162 | |
| 163 | fn create_instance_image( |
| 164 | &self, |
| 165 | virtualization_service: &dyn IVirtualizationService, |
| 166 | ) -> Result<()> { |
| 167 | let instance_image = fs::OpenOptions::new() |
| 168 | .create(true) |
| 169 | .read(true) |
| 170 | .write(true) |
| 171 | .open(&self.instance_image) |
| 172 | .context("Creating instance image file")?; |
| 173 | let instance_image = ParcelFileDescriptor::new(instance_image); |
| 174 | // TODO: Where does this number come from? |
| 175 | let size = 10 * 1024 * 1024; |
| 176 | virtualization_service |
| 177 | .initializeWritablePartition(&instance_image, size, PartitionType::ANDROID_VM_INSTANCE) |
| 178 | .context("Writing instance image file")?; |
| 179 | Ok(()) |
| 180 | } |
| 181 | |
| 182 | fn check_files_exist(&self) -> Result<()> { |
| 183 | if !self.instance_root.is_dir() { |
| 184 | bail!("Directory {} not found", self.instance_root.display()) |
| 185 | }; |
| 186 | Self::check_file_exists(&self.instance_image)?; |
| 187 | Self::check_file_exists(&self.key_blob)?; |
| 188 | Self::check_file_exists(&self.public_key)?; |
| 189 | Ok(()) |
| 190 | } |
| 191 | |
| 192 | fn check_file_exists(file: &Path) -> Result<()> { |
| 193 | if !file.is_file() { |
| 194 | bail!("File {} not found", file.display()) |
| 195 | }; |
| 196 | Ok(()) |
| 197 | } |
| 198 | } |