Merge "Change the name of the dm device for the correct_custom_roothash test"
diff --git a/apex/Android.bp b/apex/Android.bp
index c568ae2..b1c5190 100644
--- a/apex/Android.bp
+++ b/apex/Android.bp
@@ -81,4 +81,5 @@
     name: "com.android.virt.init.rc",
     src: "virtualizationservice.rc",
     filename: "init.rc",
+    installable: false,
 }
diff --git a/apkdmverity/src/main.rs b/apkdmverity/src/main.rs
index 5597e22..b240c85 100644
--- a/apkdmverity/src/main.rs
+++ b/apkdmverity/src/main.rs
@@ -240,8 +240,7 @@
         }
 
         run_test(modified_apk.as_slice(), idsig.as_ref(), "incorrect_apk", |ctx| {
-            let ret = fs::read(&ctx.result.mapper_device).map_err(|e| e.kind());
-            assert_eq!(ret, Err(std::io::ErrorKind::Other));
+            fs::read(&ctx.result.mapper_device).expect_err("Should fail");
         });
     }
 
@@ -261,8 +260,7 @@
         }
 
         run_test(apk.as_ref(), modified_idsig.as_slice(), "incorrect_merkle_tree", |ctx| {
-            let ret = fs::read(&ctx.result.mapper_device).map_err(|e| e.kind());
-            assert_eq!(ret, Err(std::io::ErrorKind::Other));
+            fs::read(&ctx.result.mapper_device).expect_err("Should fail");
         });
     }
 
@@ -284,9 +282,7 @@
             // Read around the modified location causes an error
             let f = File::open(&ctx.result.mapper_device).unwrap();
             let mut buf = vec![0; 10]; // just read 10 bytes
-            let ret = f.read_at(&mut buf, MODIFIED_OFFSET).map_err(|e| e.kind());
-            assert!(ret.is_err());
-            assert_eq!(ret, Err(std::io::ErrorKind::Other));
+            f.read_at(&mut buf, MODIFIED_OFFSET).expect_err("Should fail");
         });
     }
 
diff --git a/apkverify/src/lib.rs b/apkverify/src/lib.rs
index f75913c..71ea857 100644
--- a/apkverify/src/lib.rs
+++ b/apkverify/src/lib.rs
@@ -26,8 +26,14 @@
 use anyhow::Result;
 use std::path::Path;
 
-/// Verifies APK/APEX signing with v2/v3 scheme
-pub fn verify<P: AsRef<Path>>(path: P) -> Result<()> {
+/// Verifies APK/APEX signing with v2/v3 scheme. On success, the public key (in DER format) is
+/// returned.
+pub fn verify<P: AsRef<Path>>(path: P) -> Result<Box<[u8]>> {
     // TODO(jooyung) fallback to v2 when v3 not found
     v3::verify(path)
 }
+
+/// Gets the public key (in DER format) that was used to sign the given APK/APEX file
+pub fn get_public_key_der<P: AsRef<Path>>(path: P) -> Result<Box<[u8]>> {
+    v3::get_public_key_der(path)
+}
diff --git a/apkverify/src/v3.rs b/apkverify/src/v3.rs
index 2f9ce94..797911b 100644
--- a/apkverify/src/v3.rs
+++ b/apkverify/src/v3.rs
@@ -86,40 +86,50 @@
 type X509Certificate = Bytes;
 type AdditionalAttributes = Bytes;
 
-/// Verifies APK Signature Scheme v3 signatures of the provided APK and returns the certificates
-/// associated with each signer.
-pub fn verify<P: AsRef<Path>>(path: P) -> Result<()> {
+/// Verifies APK Signature Scheme v3 signatures of the provided APK and returns the public key
+/// associated with the signer.
+pub fn verify<P: AsRef<Path>>(path: P) -> Result<Box<[u8]>> {
     let f = File::open(path.as_ref())?;
     let mut sections = ApkSections::new(f)?;
-    verify_signature(&mut sections)?;
-    Ok(())
+    find_signer_and_then(&mut sections, |(signer, sections)| signer.verify(sections))
 }
 
-/// Verifies the contents of the provided APK file against the provided APK Signature Scheme v3
-/// Block.
-fn verify_signature<R: Read + Seek>(sections: &mut ApkSections<R>) -> Result<()> {
+/// Finds the supported signer and execute a function on it.
+fn find_signer_and_then<R, U, F>(sections: &mut ApkSections<R>, f: F) -> Result<U>
+where
+    R: Read + Seek,
+    F: FnOnce((&Signer, &mut ApkSections<R>)) -> Result<U>,
+{
     let mut block = sections.find_signature(APK_SIGNATURE_SCHEME_V3_BLOCK_ID)?;
-
     // parse v3 scheme block
     let signers = block.read::<Signers>()?;
 
     // find supported by platform
-    let mut supported =
-        signers.iter().filter(|s| s.sdk_range().contains(&SDK_INT)).collect::<Vec<_>>();
+    let supported = signers.iter().filter(|s| s.sdk_range().contains(&SDK_INT)).collect::<Vec<_>>();
 
     // there should be exactly one
     if supported.len() != 1 {
-        bail!("APK Signature Scheme V3 only supports one signer: {} signers found.", signers.len())
+        bail!(
+            "APK Signature Scheme V3 only supports one signer: {} signers found.",
+            supported.len()
+        )
     }
 
-    // and it should be verified
-    supported.pop().unwrap().verify(sections)?;
+    // Call the supplied function
+    f((supported[0], sections))
+}
 
-    Ok(())
+/// Gets the public key (in DER format) that was used to sign the given APK/APEX file
+pub fn get_public_key_der<P: AsRef<Path>>(path: P) -> Result<Box<[u8]>> {
+    let f = File::open(path.as_ref())?;
+    let mut sections = ApkSections::new(f)?;
+    find_signer_and_then(&mut sections, |(signer, _)| {
+        Ok(signer.public_key.to_vec().into_boxed_slice())
+    })
 }
 
 impl Signer {
-    fn verify<R: Read + Seek>(&self, sections: &mut ApkSections<R>) -> Result<()> {
+    fn verify<R: Read + Seek>(&self, sections: &mut ApkSections<R>) -> Result<Box<[u8]>> {
         // 1. Choose the strongest supported signature algorithm ID from signatures. The strength
         //    ordering is up to each implementation/platform version.
         let strongest: &Signature = self
@@ -181,7 +191,7 @@
         }
 
         // TODO(jooyung) 8. If the proof-of-rotation attribute exists for the signer verify that the struct is valid and this signer is the last certificate in the list.
-        Ok(())
+        Ok(self.public_key.to_vec().into_boxed_slice())
     }
 }
 
diff --git a/compos/apex/Android.bp b/compos/apex/Android.bp
index 853b9f4..ada0976 100644
--- a/compos/apex/Android.bp
+++ b/compos/apex/Android.bp
@@ -40,6 +40,7 @@
     binaries: [
         "compos_key_cmd",
         "compos_verify_key",
+        "composd",
         "compsvc",
         "pvm_exec",
     ],
@@ -50,5 +51,13 @@
 
     prebuilts: [
         "CompOSPayloadApp.apk.idsig",
+        "com.android.compos.init.rc",
     ],
 }
+
+prebuilt_etc {
+    name: "com.android.compos.init.rc",
+    src: "composd.rc",
+    filename: "init.rc",
+    installable: false,
+}
diff --git a/compos/apex/composd.rc b/compos/apex/composd.rc
new file mode 100644
index 0000000..099a346
--- /dev/null
+++ b/compos/apex/composd.rc
@@ -0,0 +1,21 @@
+# Copyright (C) 2021 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.
+
+service composd /apex/com.android.compos/bin/composd
+    class main
+    user system
+    group system
+    interface aidl android.system.composd
+    disabled
+    oneshot
diff --git a/compos/compos_key_cmd/Android.bp b/compos/compos_key_cmd/Android.bp
index e0584f4..36c1b5c 100644
--- a/compos/compos_key_cmd/Android.bp
+++ b/compos/compos_key_cmd/Android.bp
@@ -15,8 +15,8 @@
         "android.system.virtualizationservice-ndk",
         "compos_aidl_interface-ndk",
         "libbase",
-        "libbinder_rpc_unstable",
         "libbinder_ndk",
+        "libbinder_rpc_unstable",
         "libcrypto",
         "libfsverity",
         "libprotobuf-cpp-lite",
diff --git a/compos/compos_key_cmd/compos_key_cmd.cpp b/compos/compos_key_cmd/compos_key_cmd.cpp
index eb11d92..ff53548 100644
--- a/compos/compos_key_cmd/compos_key_cmd.cpp
+++ b/compos/compos_key_cmd/compos_key_cmd.cpp
@@ -33,6 +33,7 @@
 #include <openssl/x509.h>
 #include <unistd.h>
 
+#include <binder_rpc_unstable.hpp>
 #include <chrono>
 #include <condition_variable>
 #include <filesystem>
@@ -43,11 +44,6 @@
 
 #include "compos_signature.pb.h"
 
-// From frameworks/native/libs/binder/rust/src/binder_rpc_unstable.hpp
-extern "C" {
-AIBinder* RpcClient(unsigned int cid, unsigned int port);
-}
-
 using namespace std::literals;
 
 using aidl::android::system::virtualizationservice::BnVirtualMachineCallback;
diff --git a/compos/composd/Android.bp b/compos/composd/Android.bp
new file mode 100644
index 0000000..007eda9
--- /dev/null
+++ b/compos/composd/Android.bp
@@ -0,0 +1,22 @@
+package {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+rust_binary {
+    name: "composd",
+    srcs: ["src/composd_main.rs"],
+    edition: "2018",
+    rustlibs: [
+        "android.system.composd-rust",
+        "compos_aidl_interface-rust",
+        "libandroid_logger",
+        "libanyhow",
+        "libbinder_rs",
+        "libcompos_common",
+        "liblog_rust",
+    ],
+    prefer_rlib: true,
+    apex_available: [
+        "com.android.compos",
+    ],
+}
diff --git a/compos/composd/aidl/Android.bp b/compos/composd/aidl/Android.bp
new file mode 100644
index 0000000..90c0de0
--- /dev/null
+++ b/compos/composd/aidl/Android.bp
@@ -0,0 +1,21 @@
+package {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+aidl_interface {
+    name: "android.system.composd",
+    srcs: ["android/system/composd/*.aidl"],
+    // TODO: Make this stable when the APEX becomes updatable.
+    unstable: true,
+    backend: {
+        java: {
+            apex_available: ["//apex_available:platform"],
+        },
+        rust: {
+            enabled: true,
+            apex_available: [
+                "com.android.compos",
+            ],
+        },
+    },
+}
diff --git a/compos/composd/aidl/android/system/composd/IIsolatedCompilationService.aidl b/compos/composd/aidl/android/system/composd/IIsolatedCompilationService.aidl
new file mode 100644
index 0000000..0dd5b6f
--- /dev/null
+++ b/compos/composd/aidl/android/system/composd/IIsolatedCompilationService.aidl
@@ -0,0 +1,21 @@
+/*
+ * Copyright 2021 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.
+ */
+package android.system.composd;
+
+interface IIsolatedCompilationService {
+    // TODO: Add real methods
+    void doSomething();
+}
diff --git a/compos/composd/src/composd_main.rs b/compos/composd/src/composd_main.rs
new file mode 100644
index 0000000..f674448
--- /dev/null
+++ b/compos/composd/src/composd_main.rs
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+//! Exposes an on-demand binder service to perform system compilation tasks using CompOS. It is
+//! responsible for managing the lifecycle of the CompOS VM instances, providing key management for
+//! them, and orchestrating trusted compilation.
+
+mod service;
+
+use android_system_composd::binder::{register_lazy_service, ProcessState};
+use anyhow::{Context, Result};
+use log::{error, info};
+
+fn try_main() -> Result<()> {
+    android_logger::init_once(
+        android_logger::Config::default().with_tag("composd").with_min_level(log::Level::Info),
+    );
+
+    let service = service::new_binder();
+    register_lazy_service("android.system.composd", service.as_binder())
+        .context("Registering service")?;
+
+    info!("Registered service, joining threadpool");
+    ProcessState::join_thread_pool();
+
+    info!("Exiting");
+    Ok(())
+}
+
+fn main() {
+    if let Err(e) = try_main() {
+        error!("{}", e);
+        std::process::exit(1)
+    }
+}
diff --git a/compos/composd/src/service.rs b/compos/composd/src/service.rs
new file mode 100644
index 0000000..8fe28ec
--- /dev/null
+++ b/compos/composd/src/service.rs
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+//! Implementation of IIsolatedCompilationService, called from system server when compilation is
+//! desired.
+
+use android_system_composd::aidl::android::system::composd::IIsolatedCompilationService::{
+    BnIsolatedCompilationService, IIsolatedCompilationService,
+};
+use android_system_composd::binder::{self, BinderFeatures, Interface, Strong};
+
+pub struct IsolatedCompilationService {}
+
+pub fn new_binder() -> Strong<dyn IIsolatedCompilationService> {
+    let service = IsolatedCompilationService {};
+    BnIsolatedCompilationService::new_binder(service, BinderFeatures::default())
+}
+
+impl IsolatedCompilationService {}
+
+impl Interface for IsolatedCompilationService {}
+
+impl IIsolatedCompilationService for IsolatedCompilationService {
+    fn doSomething(&self) -> binder::Result<()> {
+        Ok(())
+    }
+}
diff --git a/libs/libavb_rs/Android.bp b/libs/libavb_rs/Android.bp
new file mode 100644
index 0000000..1035498
--- /dev/null
+++ b/libs/libavb_rs/Android.bp
@@ -0,0 +1,31 @@
+package {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+rust_bindgen {
+    name: "libavb_bindgen",
+    wrapper_src: "bindgen/avb.h",
+    crate_name: "avb_bindgen",
+    source_stem: "bindings",
+    bindgen_flags: [
+        "--size_t-is-usize",
+        "--allowlist-function=.*",
+    ],
+    static_libs: [
+        "libavb",
+    ],
+    shared_libs: [
+        "libcrypto",
+    ],
+    cflags: ["-DBORINGSSL_NO_CXX"],
+}
+
+rust_test {
+    name: "libavb_bindgen_test",
+    srcs: [":libavb_bindgen"],
+    crate_name: "avb_bindgen_test",
+    test_suites: ["general-tests"],
+    auto_gen_config: true,
+    clippy_lints: "none",
+    lints: "none",
+}
diff --git a/libs/libavb_rs/bindgen/avb.h b/libs/libavb_rs/bindgen/avb.h
new file mode 100644
index 0000000..b3d5385
--- /dev/null
+++ b/libs/libavb_rs/bindgen/avb.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2021 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 <libavb/libavb.h>
diff --git a/microdroid/payload/metadata.proto b/microdroid/payload/metadata.proto
index 4c32dde..5ae2158 100644
--- a/microdroid/payload/metadata.proto
+++ b/microdroid/payload/metadata.proto
@@ -31,14 +31,13 @@
 
 message ApexPayload {
   // Required.
-  // The apex name.
   string name = 1;
-
   string partition_name = 2;
 
   // Optional.
-  // When specified, the public key used to sign the apex should match with it.
+  // When specified, apex payload should be verified with the public key and root digest.
   bytes public_key = 3;
+  bytes root_digest = 4;
 }
 
 message ApkPayload {
diff --git a/microdroid_manager/Android.bp b/microdroid_manager/Android.bp
index 9957689..721f9fa 100644
--- a/microdroid_manager/Android.bp
+++ b/microdroid_manager/Android.bp
@@ -13,6 +13,7 @@
         "android.system.virtualmachineservice-rust",
         "libanyhow",
         "libapkverify",
+        "libavb_bindgen",
         "libbinder_rpc_unstable_bindgen",
         "libbinder_rs",
         "libbyteorder",
@@ -63,4 +64,5 @@
             enabled: false,
         },
     },
+    data: ["tests/data/*"],
 }
diff --git a/microdroid_manager/src/instance.rs b/microdroid_manager/src/instance.rs
index 73983a7..47230e3 100644
--- a/microdroid_manager/src/instance.rs
+++ b/microdroid_manager/src/instance.rs
@@ -320,7 +320,7 @@
 #[derive(Debug, Serialize, Deserialize, PartialEq)]
 pub struct ApkData {
     pub root_hash: Box<RootHash>,
-    // TODO(b/199143508) add cert
+    pub pubkey: Box<[u8]>,
 }
 
 pub type RootHash = [u8];
@@ -328,5 +328,6 @@
 #[derive(Debug, Serialize, Deserialize, PartialEq)]
 pub struct ApexData {
     pub name: String,
-    pub pubkey: Vec<u8>,
+    pub public_key: Vec<u8>,
+    pub root_digest: Vec<u8>,
 }
diff --git a/microdroid_manager/src/main.rs b/microdroid_manager/src/main.rs
index 204feab..4953a4c 100644
--- a/microdroid_manager/src/main.rs
+++ b/microdroid_manager/src/main.rs
@@ -20,7 +20,7 @@
 
 use crate::instance::{ApkData, InstanceDisk, MicrodroidData, RootHash};
 use anyhow::{anyhow, bail, ensure, Context, Result};
-use apkverify::verify;
+use apkverify::{get_public_key_der, verify};
 use binder::unstable_api::{new_spibinder, AIBinder};
 use binder::{FromIBinder, Strong};
 use idsig::V4Signature;
@@ -162,14 +162,15 @@
     // Start apkdmverity and wait for the dm-verify block
     system_properties::write("ctl.start", "apkdmverity")?;
 
-    // While waiting for apkdmverity to mount APK, gathers APEX pubkeys from payload.
+    // While waiting for apkdmverity to mount APK, gathers public keys and root digests from
+    // APEX payload.
     let apex_data_from_payload = get_apex_data_from_payload(metadata)?;
     if let Some(saved_data) = saved_data.map(|d| &d.apex_data) {
-        // For APEX payload, we don't support updating their pubkeys
+        // We don't support APEX updates. (assuming that update will change root digest)
         ensure!(saved_data == &apex_data_from_payload, "APEX payloads has changed.");
         let apex_metadata = to_metadata(&apex_data_from_payload);
-        // Pass metadata(with pubkeys) to apexd so that it uses the passed metadata
-        // instead of the default one (/dev/block/by-name/payload-metadata)
+        // Pass metadata(with public keys and root digests) to apexd so that it uses the passed
+        // metadata instead of the default one (/dev/block/by-name/payload-metadata)
         OpenOptions::new()
             .create_new(true)
             .write(true)
@@ -187,16 +188,18 @@
     // taken only when the root_hash is un-trustful which can be either when this is the first boot
     // of the VM or APK was updated in the host.
     // TODO(jooyung): consider multithreading to make this faster
-    if !root_hash_trustful {
-        verify(DM_MOUNTED_APK_PATH).context(format!("failed to verify {}", DM_MOUNTED_APK_PATH))?;
-    }
+    let apk_pubkey = if !root_hash_trustful {
+        verify(DM_MOUNTED_APK_PATH).context(format!("failed to verify {}", DM_MOUNTED_APK_PATH))?
+    } else {
+        get_public_key_der(DM_MOUNTED_APK_PATH)?
+    };
 
     info!("payload verification successful. took {:#?}", start_time.elapsed().unwrap());
 
     // At this point, we can ensure that the root_hash from the idsig file is trusted, either by
     // fully verifying the APK or by comparing it with the saved root_hash.
     Ok(MicrodroidData {
-        apk_data: ApkData { root_hash: root_hash_from_idsig },
+        apk_data: ApkData { root_hash: root_hash_from_idsig, pubkey: apk_pubkey },
         apex_data: apex_data_from_payload,
     })
 }
diff --git a/microdroid_manager/src/payload.rs b/microdroid_manager/src/payload.rs
index bf9d9f9..8ec6f74 100644
--- a/microdroid_manager/src/payload.rs
+++ b/microdroid_manager/src/payload.rs
@@ -17,14 +17,11 @@
 use crate::instance::ApexData;
 use crate::ioutil::wait_for_file;
 use anyhow::Result;
+use apex::verify;
 use log::info;
 use microdroid_metadata::{read_metadata, ApexPayload, Metadata};
-use std::fs::File;
-use std::io::Read;
 use std::time::Duration;
-use zip::ZipArchive;
 
-const APEX_PUBKEY_ENTRY: &str = "apex_pubkey";
 const PAYLOAD_METADATA_PATH: &str = "/dev/block/by-name/payload-metadata";
 const WAIT_TIMEOUT: Duration = Duration::from_secs(10);
 
@@ -35,29 +32,20 @@
     read_metadata(file)
 }
 
-/// Loads (name, pubkey) from payload APEXes
+/// Loads (name, public_key, root_digest) from payload APEXes
 pub fn get_apex_data_from_payload(metadata: &Metadata) -> Result<Vec<ApexData>> {
     metadata
         .apexes
         .iter()
         .map(|apex| {
             let name = apex.name.clone();
-            let partition = format!("/dev/block/by-name/{}", apex.partition_name);
-            let pubkey = get_pubkey_from_apex(&partition)?;
-            Ok(ApexData { name, pubkey })
+            let apex_path = format!("/dev/block/by-name/{}", apex.partition_name);
+            let result = verify(&apex_path)?;
+            Ok(ApexData { name, public_key: result.public_key, root_digest: result.root_digest })
         })
         .collect()
 }
 
-fn get_pubkey_from_apex(path: &str) -> Result<Vec<u8>> {
-    let f = File::open(path)?;
-    let mut z = ZipArchive::new(f)?;
-    let mut pubkey_file = z.by_name(APEX_PUBKEY_ENTRY)?;
-    let mut pubkey = Vec::new();
-    pubkey_file.read_to_end(&mut pubkey)?;
-    Ok(pubkey)
-}
-
 /// Convert vector of ApexData into Metadata
 pub fn to_metadata(apex_data: &[ApexData]) -> Metadata {
     Metadata {
@@ -65,10 +53,13 @@
             .iter()
             .map(|data| ApexPayload {
                 name: data.name.clone(),
-                public_key: data.pubkey.clone(),
+                public_key: data.public_key.clone(),
+                root_digest: data.root_digest.clone(),
                 ..Default::default()
             })
             .collect(),
         ..Default::default()
     }
 }
+
+mod apex;
diff --git a/microdroid_manager/src/payload/apex.rs b/microdroid_manager/src/payload/apex.rs
new file mode 100644
index 0000000..24c4f05
--- /dev/null
+++ b/microdroid_manager/src/payload/apex.rs
@@ -0,0 +1,225 @@
+// Copyright 2021, 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.
+
+//! Routines for handling APEX payload
+
+use anyhow::{anyhow, ensure, Result};
+use avb_bindgen::*;
+use std::ffi::{c_void, CStr};
+use std::fs::File;
+use std::io::{Read, Seek, SeekFrom};
+use std::mem::{size_of, zeroed};
+use std::ops::Deref;
+use std::ptr::null_mut;
+use std::slice::{from_raw_parts, from_raw_parts_mut};
+use zip::ZipArchive;
+
+const APEX_PUBKEY_ENTRY: &str = "apex_pubkey";
+const APEX_PAYLOAD_ENTRY: &str = "apex_payload.img";
+
+/// Verification result holds public key and root digest of apex_payload.img
+pub struct ApexVerificationResult {
+    pub public_key: Vec<u8>,
+    pub root_digest: Vec<u8>,
+}
+
+/// Verify APEX payload by AVB verification and return public key and root digest
+pub fn verify(path: &str) -> Result<ApexVerificationResult> {
+    let apex_file = File::open(path)?;
+    let (public_key, image_offset, image_size) = get_public_key_and_image_info(&apex_file)?;
+    let root_digest = verify_vbmeta(apex_file, image_offset, image_size, &public_key)?;
+    Ok(ApexVerificationResult { public_key, root_digest })
+}
+
+fn get_public_key_and_image_info(apex_file: &File) -> Result<(Vec<u8>, u64, u64)> {
+    let mut z = ZipArchive::new(apex_file)?;
+
+    let mut public_key = Vec::new();
+    z.by_name(APEX_PUBKEY_ENTRY)?.read_to_end(&mut public_key)?;
+
+    let (image_offset, image_size) =
+        z.by_name(APEX_PAYLOAD_ENTRY).map(|f| (f.data_start(), f.size()))?;
+
+    Ok((public_key, image_offset, image_size))
+}
+
+// Manual addition of a missing enum
+#[allow(non_camel_case_types, dead_code)]
+#[repr(u8)]
+enum AvbDescriptorTag {
+    AVB_DESCRIPTOR_TAG_PROPERTY = 0,
+    AVB_DESCRIPTOR_TAG_HASHTREE,
+    AVB_DESCRIPTOR_TAG_HASH,
+    AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE,
+    AVB_DESCRIPTOR_TAG_CHAIN_PARTITION,
+}
+
+const FOOTER_SIZE: usize = size_of::<AvbFooter>();
+const HASHTREE_DESCRIPTOR_SIZE: usize = size_of::<AvbHashtreeDescriptor>();
+
+/// Verify VBmeta image and return root digest
+fn verify_vbmeta<R: Read + Seek>(
+    image: R,
+    offset: u64,
+    size: u64,
+    public_key: &[u8],
+) -> Result<Vec<u8>> {
+    let vbmeta = VbMeta::from(image, offset, size)?;
+    vbmeta.verify(public_key)?;
+    for &descriptor in vbmeta.descriptors()?.iter() {
+        if let Ok(hashtree_descriptor) = HashtreeDescriptor::from(descriptor) {
+            return hashtree_descriptor.root_digest();
+        }
+    }
+    Err(anyhow!("HashtreeDescriptor is not found."))
+}
+
+struct VbMeta {
+    data: Vec<u8>,
+}
+
+impl VbMeta {
+    // Read a VbMeta data from a given image
+    fn from<R: Read + Seek>(mut image: R, offset: u64, size: u64) -> Result<VbMeta> {
+        // Get AvbFooter first
+        image.seek(SeekFrom::Start(offset + size - FOOTER_SIZE as u64))?;
+        // SAFETY: AvbDescriptor is a "repr(C,packed)" struct from bindgen
+        let mut footer: AvbFooter = unsafe { zeroed() };
+        // SAFETY: safe to read because of seek(-FOOTER_SIZE) above
+        unsafe {
+            let footer_slice = from_raw_parts_mut(&mut footer as *mut _ as *mut u8, FOOTER_SIZE);
+            image.read_exact(footer_slice)?;
+            ensure!(avb_footer_validate_and_byteswap(&footer, &mut footer));
+        }
+        // Get VbMeta block
+        image.seek(SeekFrom::Start(offset + footer.vbmeta_offset))?;
+        let vbmeta_size = footer.vbmeta_size as usize;
+        let mut data = vec![0u8; vbmeta_size];
+        image.read_exact(&mut data)?;
+        Ok(VbMeta { data })
+    }
+    // Verify VbMeta image. Its enclosed public key should match with a given public key.
+    fn verify(&self, outer_public_key: &[u8]) -> Result<()> {
+        // SAFETY: self.data points to a valid VBMeta data and avb_vbmeta_image_verify should work fine
+        // with it
+        let public_key = unsafe {
+            let mut pk_ptr: *const u8 = null_mut();
+            let mut pk_len: usize = 0;
+            let res = avb_vbmeta_image_verify(
+                self.data.as_ptr(),
+                self.data.len(),
+                &mut pk_ptr,
+                &mut pk_len,
+            );
+            ensure!(
+                res == AvbVBMetaVerifyResult_AVB_VBMETA_VERIFY_RESULT_OK,
+                CStr::from_ptr(avb_vbmeta_verify_result_to_string(res))
+                    .to_string_lossy()
+                    .into_owned()
+            );
+            from_raw_parts(pk_ptr, pk_len)
+        };
+
+        ensure!(public_key == outer_public_key, "Public key mismatch with a given one.");
+        Ok(())
+    }
+    // Return a slice of AvbDescriptor pointers
+    fn descriptors(&self) -> Result<Descriptors> {
+        let mut num: usize = 0;
+        // SAFETY: ptr will be freed by Descriptor.
+        Ok(unsafe {
+            let ptr = avb_descriptor_get_all(self.data.as_ptr(), self.data.len(), &mut num);
+            ensure!(!ptr.is_null(), "VbMeta has no descriptors.");
+            let all = from_raw_parts(ptr, num);
+            Descriptors { ptr, all }
+        })
+    }
+}
+
+struct HashtreeDescriptor {
+    ptr: *const u8,
+    inner: AvbHashtreeDescriptor,
+}
+
+impl HashtreeDescriptor {
+    fn from(descriptor: *const AvbDescriptor) -> Result<HashtreeDescriptor> {
+        // SAFETY: AvbDescriptor is a "repr(C,packed)" struct from bindgen
+        let mut desc: AvbDescriptor = unsafe { zeroed() };
+        // SAFETY: both points to valid AvbDescriptor pointers
+        unsafe {
+            ensure!(avb_descriptor_validate_and_byteswap(descriptor, &mut desc));
+        }
+        ensure!({ desc.tag } == AvbDescriptorTag::AVB_DESCRIPTOR_TAG_HASHTREE as u64);
+        // SAFETY: AvbHashtreeDescriptor is a "repr(C, packed)" struct from bindgen
+        let mut hashtree_descriptor: AvbHashtreeDescriptor = unsafe { zeroed() };
+        // SAFETY: With tag == AVB_DESCRIPTOR_TAG_HASHTREE, descriptor should point to
+        // a AvbHashtreeDescriptor.
+        unsafe {
+            ensure!(avb_hashtree_descriptor_validate_and_byteswap(
+                descriptor as *const AvbHashtreeDescriptor,
+                &mut hashtree_descriptor,
+            ));
+        }
+        Ok(Self { ptr: descriptor as *const u8, inner: hashtree_descriptor })
+    }
+    fn root_digest(&self) -> Result<Vec<u8>> {
+        // SAFETY: digest_ptr should point to a valid buffer of root_digest_len
+        let root_digest = unsafe {
+            let digest_ptr = self.ptr.offset(
+                HASHTREE_DESCRIPTOR_SIZE as isize
+                    + self.inner.partition_name_len as isize
+                    + self.inner.salt_len as isize,
+            );
+            from_raw_parts(digest_ptr, self.inner.root_digest_len as usize)
+        };
+        Ok(root_digest.to_owned())
+    }
+}
+
+// Wraps pointer to a heap-allocated array of AvbDescriptor pointers
+struct Descriptors<'a> {
+    ptr: *mut *const AvbDescriptor,
+    all: &'a [*const AvbDescriptor],
+}
+
+// Wrapped pointer should be freed with avb_free.
+impl Drop for Descriptors<'_> {
+    fn drop(&mut self) {
+        // SAFETY: ptr is allocated by avb_descriptor_get_all
+        unsafe { avb_free(self.ptr as *mut c_void) }
+    }
+}
+
+impl<'a> Deref for Descriptors<'a> {
+    type Target = &'a [*const AvbDescriptor];
+    fn deref(&self) -> &Self::Target {
+        &self.all
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    fn to_hex_string(buf: &[u8]) -> String {
+        buf.iter().map(|b| format!("{:02x}", b)).collect()
+    }
+    #[test]
+    fn test_open_apex() {
+        let res = verify("tests/data/test.apex").unwrap();
+        assert_eq!(
+            to_hex_string(&res.root_digest),
+            "fe11ab17da0a3a738b54bdc3a13f6139cbdf91ec32f001f8d4bbbf8938e04e39"
+        );
+    }
+}
diff --git a/microdroid_manager/tests/data/README.md b/microdroid_manager/tests/data/README.md
new file mode 100644
index 0000000..82ebec6
--- /dev/null
+++ b/microdroid_manager/tests/data/README.md
@@ -0,0 +1,3 @@
+# Test data
+
+- test.apex: copied from system/apexshim/prebuilts/x86/com.android.apex.cts.shim.v1.apex
\ No newline at end of file
diff --git a/microdroid_manager/tests/data/test.apex b/microdroid_manager/tests/data/test.apex
new file mode 100644
index 0000000..fd79365
--- /dev/null
+++ b/microdroid_manager/tests/data/test.apex
Binary files differ
diff --git a/virtualizationservice/src/aidl.rs b/virtualizationservice/src/aidl.rs
index b0ea0ba..449103e 100644
--- a/virtualizationservice/src/aidl.rs
+++ b/virtualizationservice/src/aidl.rs
@@ -35,7 +35,7 @@
     VirtualMachineState::VirtualMachineState,
 };
 use android_system_virtualizationservice::binder::{
-    self, BinderFeatures, ExceptionCode, Interface, ParcelFileDescriptor, Status, Strong, ThreadState,
+    self, force_lazy_services_persist, BinderFeatures, ExceptionCode, Interface, ParcelFileDescriptor, Status, Strong, ThreadState,
 };
 use android_system_virtualmachineservice::aidl::android::system::virtualmachineservice::IVirtualMachineService::{
     VM_BINDER_SERVICE_PORT, VM_STREAM_SERVICE_PORT, BnVirtualMachineService, IVirtualMachineService,
@@ -716,12 +716,20 @@
     /// Store a strong VM reference.
     fn debug_hold_vm(&mut self, vm: Strong<dyn IVirtualMachine>) {
         self.debug_held_vms.push(vm);
+        // Make sure our process is not shut down while we hold the VM reference
+        // on behalf of the caller.
+        force_lazy_services_persist(true);
     }
 
     /// Retrieve and remove a strong VM reference.
     fn debug_drop_vm(&mut self, cid: i32) -> Option<Strong<dyn IVirtualMachine>> {
         let pos = self.debug_held_vms.iter().position(|vm| vm.getCid() == Ok(cid))?;
-        Some(self.debug_held_vms.swap_remove(pos))
+        let vm = self.debug_held_vms.swap_remove(pos);
+        if self.debug_held_vms.is_empty() {
+            // Once we no longer hold any VM references it is ok for our process to be shut down.
+            force_lazy_services_persist(false);
+        }
+        Some(vm)
     }
 
     /// Get the next available CID, or an error if we have run out.
diff --git a/virtualizationservice/src/main.rs b/virtualizationservice/src/main.rs
index 8628c01..22ddf08 100644
--- a/virtualizationservice/src/main.rs
+++ b/virtualizationservice/src/main.rs
@@ -21,7 +21,7 @@
 
 use crate::aidl::{VirtualizationService, BINDER_SERVICE_IDENTIFIER, TEMPORARY_DIRECTORY};
 use android_system_virtualizationservice::aidl::android::system::virtualizationservice::IVirtualizationService::BnVirtualizationService;
-use android_system_virtualizationservice::binder::{add_service, BinderFeatures, ProcessState};
+use android_system_virtualizationservice::binder::{register_lazy_service, BinderFeatures, ProcessState};
 use anyhow::Error;
 use log::{info, Level};
 use std::fs::{remove_dir_all, remove_file, read_dir};
@@ -47,7 +47,7 @@
         service,
         BinderFeatures { set_requesting_sid: true, ..BinderFeatures::default() },
     );
-    add_service(BINDER_SERVICE_IDENTIFIER, service.as_binder()).unwrap();
+    register_lazy_service(BINDER_SERVICE_IDENTIFIER, service.as_binder()).unwrap();
     info!("Registered Binder service, joining threadpool.");
     ProcessState::join_thread_pool();
 }