Create a Rust wrapper for vm_payload
And use it in place of directly calling the bindgen-generated
interface in our current clients.
Bug: 340857915
Test: atest VmAttestationTestApp
composd_cmd test-compile
Change-Id: I51f1c1ab6a4dce09d9160731aacd83ebb9c0ce07
diff --git a/compos/Android.bp b/compos/Android.bp
index b840506..220533a 100644
--- a/compos/Android.bp
+++ b/compos/Android.bp
@@ -25,7 +25,7 @@
"librpcbinder_rs",
"librustutils",
"libscopeguard",
- "libvm_payload_bindgen",
+ "libvm_payload_rs",
],
prefer_rlib: true,
shared_libs: [
diff --git a/compos/src/compsvc_main.rs b/compos/src/compsvc_main.rs
index 06cc599..9bc522c 100644
--- a/compos/src/compsvc_main.rs
+++ b/compos/src/compsvc_main.rs
@@ -23,13 +23,9 @@
mod fsverity;
use anyhow::Result;
-use binder::unstable_api::AsNative;
use compos_common::COMPOS_VSOCK_PORT;
use log::{debug, error};
-use std::os::raw::c_void;
use std::panic;
-use std::ptr;
-use vm_payload_bindgen::{AIBinder, AVmPayload_notifyPayloadReady, AVmPayload_runVsockRpcServer};
fn main() {
if let Err(e) = try_main() {
@@ -50,17 +46,5 @@
}));
debug!("compsvc is starting as a rpc service.");
- let param = ptr::null_mut();
- let mut service = compsvc::new_binder()?.as_binder();
- let service = service.as_native_mut() as *mut AIBinder;
- // SAFETY: We hold a strong pointer, so the raw pointer remains valid. The bindgen AIBinder
- // is the same type as sys::AIBinder. It is safe for on_ready to be invoked at any time, with
- // any parameter.
- unsafe { AVmPayload_runVsockRpcServer(service, COMPOS_VSOCK_PORT, Some(on_ready), param) }
-}
-
-extern "C" fn on_ready(_param: *mut c_void) {
- // SAFETY: Invokes a method from the bindgen library `vm_payload_bindgen` which is safe to
- // call at any time.
- unsafe { AVmPayload_notifyPayloadReady() };
+ vm_payload::run_single_vsock_service(compsvc::new_binder()?, COMPOS_VSOCK_PORT)
}
diff --git a/service_vm/demo_apk/Android.bp b/service_vm/demo_apk/Android.bp
index 3750fe6..c64b70a 100644
--- a/service_vm/demo_apk/Android.bp
+++ b/service_vm/demo_apk/Android.bp
@@ -23,7 +23,7 @@
"libandroid_logger",
"libanyhow",
"liblog_rust",
- "libvm_payload_bindgen",
+ "libvm_payload_rs",
],
}
diff --git a/service_vm/demo_apk/src/main.rs b/service_vm/demo_apk/src/main.rs
index 8ea4e65..26df52c 100644
--- a/service_vm/demo_apk/src/main.rs
+++ b/service_vm/demo_apk/src/main.rs
@@ -14,25 +14,15 @@
//! Main executable of Service VM client for manual testing.
-use anyhow::{anyhow, ensure, Result};
+use anyhow::{ensure, Context, Result};
use log::{error, info};
-use std::{
- ffi::{c_void, CStr},
- panic,
- ptr::{self, NonNull},
- result,
-};
-use vm_payload_bindgen::{
- AVmAttestationResult, AVmAttestationResult_free, AVmAttestationResult_getCertificateAt,
- AVmAttestationResult_getCertificateCount, AVmAttestationResult_getPrivateKey,
- AVmAttestationResult_sign, AVmAttestationStatus, AVmAttestationStatus_toString,
- AVmPayload_requestAttestation,
-};
+use std::panic;
+use vm_payload::AttestationError;
+
+vm_payload::main!(main);
/// Entry point of the Service VM client.
-#[allow(non_snake_case)]
-#[no_mangle]
-pub extern "C" fn AVmPayload_main() {
+fn main() {
android_logger::init_once(
android_logger::Config::default()
.with_tag("service_vm_client")
@@ -52,15 +42,11 @@
info!("Welcome to Service VM Client!");
let too_big_challenge = &[0u8; 66];
- let res = AttestationResult::request_attestation(too_big_challenge);
+ let res = vm_payload::request_attestation(too_big_challenge);
ensure!(res.is_err());
- let status = res.unwrap_err();
- ensure!(
- status == AVmAttestationStatus::ATTESTATION_ERROR_INVALID_CHALLENGE,
- "Unexpected status: {:?}",
- status
- );
- info!("Status: {:?}", status_to_cstr(status));
+ let error = res.unwrap_err();
+ ensure!(error == AttestationError::InvalidChallenge, "Unexpected error: {error:?}");
+ info!("Error: {error}");
// The data below is only a placeholder generated randomly with urandom
let challenge = &[
@@ -68,162 +54,18 @@
0x67, 0xc3, 0x3e, 0x73, 0x9b, 0x30, 0xbd, 0x04, 0x20, 0x2e, 0xde, 0x3b, 0x1d, 0xc8, 0x07,
0x11, 0x7b,
];
- let res = AttestationResult::request_attestation(challenge)
- .map_err(|e| anyhow!("Unexpected status: {:?}", status_to_cstr(e)))?;
+ let res = vm_payload::request_attestation(challenge).context("Unexpected attestation error")?;
- let cert_chain = res.certificate_chain()?;
+ let cert_chain: Vec<_> = res.certificate_chain().collect();
info!("Attestation result certificateChain = {:?}", cert_chain);
- let private_key = res.private_key()?;
+ let private_key = res.private_key();
info!("Attestation result privateKey = {:?}", private_key);
let message = b"Hello from Service VM client";
info!("Signing message: {:?}", message);
- let signature = res.sign(message)?;
+ let signature = res.sign_message(message);
info!("Signature: {:?}", signature);
Ok(())
}
-
-#[derive(Debug)]
-struct AttestationResult(NonNull<AVmAttestationResult>);
-
-impl AttestationResult {
- fn request_attestation(challenge: &[u8]) -> result::Result<Self, AVmAttestationStatus> {
- let mut res: *mut AVmAttestationResult = ptr::null_mut();
- // SAFETY: It is safe as we only read the challenge within its bounds and the
- // function does not retain any reference to it.
- let status = unsafe {
- AVmPayload_requestAttestation(
- challenge.as_ptr() as *const c_void,
- challenge.len(),
- &mut res,
- )
- };
- if status == AVmAttestationStatus::ATTESTATION_OK {
- info!("Attestation succeeds. Status: {:?}", status_to_cstr(status));
- let res = NonNull::new(res).expect("The attestation result is null");
- Ok(Self(res))
- } else {
- Err(status)
- }
- }
-
- fn certificate_chain(&self) -> Result<Vec<Box<[u8]>>> {
- let num_certs = get_certificate_count(self.as_ref());
- let mut certs = Vec::with_capacity(num_certs);
- for i in 0..num_certs {
- certs.push(get_certificate_at(self.as_ref(), i)?);
- }
- Ok(certs)
- }
-
- fn private_key(&self) -> Result<Box<[u8]>> {
- get_private_key(self.as_ref())
- }
-
- fn sign(&self, message: &[u8]) -> Result<Box<[u8]>> {
- sign_with_attested_key(self.as_ref(), message)
- }
-}
-
-impl AsRef<AVmAttestationResult> for AttestationResult {
- fn as_ref(&self) -> &AVmAttestationResult {
- // SAFETY: This field is private, and only populated with a successful call to
- // `AVmPayload_requestAttestation`.
- unsafe { self.0.as_ref() }
- }
-}
-
-impl Drop for AttestationResult {
- fn drop(&mut self) {
- // SAFETY: This field is private, and only populated with a successful call to
- // `AVmPayload_requestAttestation`, and not freed elsewhere.
- unsafe { AVmAttestationResult_free(self.0.as_ptr()) };
- }
-}
-
-fn get_certificate_count(res: &AVmAttestationResult) -> usize {
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed.
- unsafe { AVmAttestationResult_getCertificateCount(res) }
-}
-
-fn get_certificate_at(res: &AVmAttestationResult, index: usize) -> Result<Box<[u8]>> {
- let size =
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed.
- unsafe { AVmAttestationResult_getCertificateAt(res, index, ptr::null_mut(), 0) };
- let mut cert = vec![0u8; size];
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed. This function only writes within the bounds of `cert`.
- // And `cert` cannot overlap `res` because we just allocated it.
- let size = unsafe {
- AVmAttestationResult_getCertificateAt(
- res,
- index,
- cert.as_mut_ptr() as *mut c_void,
- cert.len(),
- )
- };
- ensure!(size == cert.len());
- Ok(cert.into_boxed_slice())
-}
-
-fn get_private_key(res: &AVmAttestationResult) -> Result<Box<[u8]>> {
- let size =
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed.
- unsafe { AVmAttestationResult_getPrivateKey(res, ptr::null_mut(), 0) };
- let mut private_key = vec![0u8; size];
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed. This function only writes within the bounds of `private_key`.
- // And `private_key` cannot overlap `res` because we just allocated it.
- let size = unsafe {
- AVmAttestationResult_getPrivateKey(
- res,
- private_key.as_mut_ptr() as *mut c_void,
- private_key.len(),
- )
- };
- ensure!(size == private_key.len());
- Ok(private_key.into_boxed_slice())
-}
-
-fn sign_with_attested_key(res: &AVmAttestationResult, message: &[u8]) -> Result<Box<[u8]>> {
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed.
- let size = unsafe {
- AVmAttestationResult_sign(
- res,
- message.as_ptr() as *const c_void,
- message.len(),
- ptr::null_mut(),
- 0,
- )
- };
- let mut signature = vec![0u8; size];
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed. This function only writes within the bounds of `signature`.
- // And `signature` cannot overlap `res` because we just allocated it.
- let size = unsafe {
- AVmAttestationResult_sign(
- res,
- message.as_ptr() as *const c_void,
- message.len(),
- signature.as_mut_ptr() as *mut c_void,
- signature.len(),
- )
- };
- ensure!(size == signature.len());
- Ok(signature.into_boxed_slice())
-}
-
-fn status_to_cstr(status: AVmAttestationStatus) -> &'static CStr {
- // SAFETY: The function only reads the given enum status and returns a pointer to a
- // static string.
- let message = unsafe { AVmAttestationStatus_toString(status) };
- // SAFETY: The pointer returned by `AVmAttestationStatus_toString` is guaranteed to
- // point to a valid C String that lives forever.
- unsafe { CStr::from_ptr(message) }
-}
diff --git a/service_vm/test_apk/Android.bp b/service_vm/test_apk/Android.bp
index 1ba156f..58b394a 100644
--- a/service_vm/test_apk/Android.bp
+++ b/service_vm/test_apk/Android.bp
@@ -39,7 +39,7 @@
"libanyhow",
"libavflog",
"liblog_rust",
- "libvm_payload_bindgen",
+ "libvm_payload_rs",
],
}
diff --git a/service_vm/test_apk/src/native/main.rs b/service_vm/test_apk/src/native/main.rs
index 00ddff8..5f5dc1c 100644
--- a/service_vm/test_apk/src/native/main.rs
+++ b/service_vm/test_apk/src/native/main.rs
@@ -14,35 +14,26 @@
//! Main executable of VM attestation for end-to-end testing.
-use anyhow::{anyhow, ensure, Result};
+use anyhow::Result;
use avflog::LogResult;
use com_android_virt_vm_attestation_testservice::{
aidl::com::android::virt::vm_attestation::testservice::IAttestationService::{
AttestationStatus::AttestationStatus, BnAttestationService, IAttestationService,
SigningResult::SigningResult, PORT,
},
- binder::{self, unstable_api::AsNative, BinderFeatures, Interface, IntoBinderResult, Strong},
+ binder::{self, BinderFeatures, Interface, IntoBinderResult, Strong},
};
use log::{error, info};
use std::{
- ffi::{c_void, CStr},
panic,
- ptr::{self, NonNull},
- result,
sync::{Arc, Mutex},
};
-use vm_payload_bindgen::{
- AIBinder, AVmAttestationResult, AVmAttestationResult_free,
- AVmAttestationResult_getCertificateAt, AVmAttestationResult_getCertificateCount,
- AVmAttestationResult_getPrivateKey, AVmAttestationResult_sign, AVmAttestationStatus,
- AVmAttestationStatus_toString, AVmPayload_notifyPayloadReady, AVmPayload_requestAttestation,
- AVmPayload_requestAttestationForTesting, AVmPayload_runVsockRpcServer,
-};
+use vm_payload::{AttestationError, AttestationResult};
-/// Entry point of the Service VM client.
-#[allow(non_snake_case)]
-#[no_mangle]
-pub extern "C" fn AVmPayload_main() {
+vm_payload::main!(main);
+
+// Entry point of the Service VM client.
+fn main() {
android_logger::init_once(
android_logger::Config::default()
.with_tag("service_vm_client")
@@ -61,18 +52,7 @@
fn try_main() -> Result<()> {
info!("Welcome to Service VM Client!");
- let mut service = AttestationService::new_binder().as_binder();
- let service = service.as_native_mut() as *mut AIBinder;
- let param = ptr::null_mut();
- // SAFETY: We hold a strong pointer, so the raw pointer remains valid. The bindgen AIBinder
- // is the same type as `sys::AIBinder`. It is safe for `on_ready` to be invoked at any time,
- // with any parameter.
- unsafe { AVmPayload_runVsockRpcServer(service, PORT.try_into()?, Some(on_ready), param) };
-}
-
-extern "C" fn on_ready(_param: *mut c_void) {
- // SAFETY: It is safe to call `AVmPayload_notifyPayloadReady` at any time.
- unsafe { AVmPayload_notifyPayloadReady() };
+ vm_payload::run_single_vsock_service(AttestationService::new_binder(), PORT.try_into()?)
}
struct AttestationService {
@@ -88,11 +68,11 @@
}
}
+#[allow(non_snake_case)]
impl IAttestationService for AttestationService {
fn requestAttestationForTesting(&self) -> binder::Result<()> {
const CHALLENGE: &[u8] = &[0xaa; 32];
- let res = AttestationResult::request_attestation_for_testing(CHALLENGE)
- .map_err(|e| anyhow!("Unexpected status: {:?}", status_to_cstr(e)))
+ let res = vm_payload::request_attestation_for_testing(CHALLENGE)
.with_log()
.or_service_specific_exception(-1)?;
*self.res.lock().unwrap() = Some(res);
@@ -104,218 +84,46 @@
challenge: &[u8],
message: &[u8],
) -> binder::Result<SigningResult> {
- let res = match AttestationResult::request_attestation(challenge) {
+ let res: AttestationResult = match vm_payload::request_attestation(challenge) {
Ok(res) => res,
- Err(status) => {
- let status = to_attestation_status(status);
+ Err(e) => {
+ let status = to_attestation_status(e);
return Ok(SigningResult { certificateChain: vec![], signature: vec![], status });
}
};
- let certificate_chain =
- res.certificate_chain().with_log().or_service_specific_exception(-1)?;
+
+ let certificate_chain: Vec<u8> = res.certificate_chain().flatten().collect();
let status = AttestationStatus::OK;
- let signature = res.sign(message).with_log().or_service_specific_exception(-1)?;
+ let signature = res.sign_message(message);
+
Ok(SigningResult { certificateChain: certificate_chain, signature, status })
}
fn validateAttestationResult(&self) -> binder::Result<()> {
// TODO(b/191073073): Returns the attestation result to the host for validation.
- self.res.lock().unwrap().as_ref().unwrap().log().or_service_specific_exception(-1)
- }
-}
-
-fn to_attestation_status(status: AVmAttestationStatus) -> AttestationStatus {
- match status {
- AVmAttestationStatus::ATTESTATION_OK => AttestationStatus::OK,
- AVmAttestationStatus::ATTESTATION_ERROR_INVALID_CHALLENGE => {
- AttestationStatus::ERROR_INVALID_CHALLENGE
- }
- AVmAttestationStatus::ATTESTATION_ERROR_ATTESTATION_FAILED => {
- AttestationStatus::ERROR_ATTESTATION_FAILED
- }
- AVmAttestationStatus::ATTESTATION_ERROR_UNSUPPORTED => AttestationStatus::ERROR_UNSUPPORTED,
- }
-}
-
-#[derive(Debug)]
-struct AttestationResult(NonNull<AVmAttestationResult>);
-
-// Safety: `AttestationResult` is not `Send` because it contains a raw pointer to a C struct.
-unsafe impl Send for AttestationResult {}
-
-impl AttestationResult {
- fn request_attestation_for_testing(
- challenge: &[u8],
- ) -> result::Result<Self, AVmAttestationStatus> {
- let mut res: *mut AVmAttestationResult = ptr::null_mut();
- // SAFETY: It is safe as we only read the challenge within its bounds and the
- // function does not retain any reference to it.
- let status = unsafe {
- AVmPayload_requestAttestationForTesting(
- challenge.as_ptr() as *const c_void,
- challenge.len(),
- &mut res,
- )
- };
- if status == AVmAttestationStatus::ATTESTATION_OK {
- info!("Attestation succeeds. Status: {:?}", status_to_cstr(status));
- let res = NonNull::new(res).expect("The attestation result is null");
- Ok(Self(res))
- } else {
- Err(status)
- }
- }
-
- fn request_attestation(challenge: &[u8]) -> result::Result<Self, AVmAttestationStatus> {
- let mut res: *mut AVmAttestationResult = ptr::null_mut();
- // SAFETY: It is safe as we only read the challenge within its bounds and the
- // function does not retain any reference to it.
- let status = unsafe {
- AVmPayload_requestAttestation(
- challenge.as_ptr() as *const c_void,
- challenge.len(),
- &mut res,
- )
- };
- if status == AVmAttestationStatus::ATTESTATION_OK {
- info!("Attestation succeeds. Status: {:?}", status_to_cstr(status));
- let res = NonNull::new(res).expect("The attestation result is null");
- Ok(Self(res))
- } else {
- Err(status)
- }
- }
-
- fn certificate_chain(&self) -> Result<Vec<u8>> {
- let num_certs = get_certificate_count(self.as_ref());
- let mut certs = Vec::new();
- for i in 0..num_certs {
- certs.extend(get_certificate_at(self.as_ref(), i)?.iter());
- }
- Ok(certs)
- }
-
- fn private_key(&self) -> Result<Box<[u8]>> {
- get_private_key(self.as_ref())
- }
-
- fn sign(&self, message: &[u8]) -> Result<Vec<u8>> {
- sign_with_attested_key(self.as_ref(), message)
- }
-
- fn log(&self) -> Result<()> {
- let cert_chain = self.certificate_chain()?;
- info!("Attestation result certificateChain = {:?}", cert_chain);
-
- let private_key = self.private_key()?;
- info!("Attestation result privateKey = {:?}", private_key);
-
- let message = b"Hello from Service VM client";
- info!("Signing message: {:?}", message);
- let signature = self.sign(message)?;
- info!("Signature: {:?}", signature);
+ log(self.res.lock().unwrap().as_ref().unwrap());
Ok(())
}
}
-impl AsRef<AVmAttestationResult> for AttestationResult {
- fn as_ref(&self) -> &AVmAttestationResult {
- // SAFETY: This field is private, and only populated with a successful call to
- // `AVmPayload_requestAttestation`.
- unsafe { self.0.as_ref() }
+fn log(res: &AttestationResult) {
+ for (i, cert) in res.certificate_chain().enumerate() {
+ info!("Attestation result certificate {i} = {cert:?}");
}
+
+ let private_key = res.private_key();
+ info!("Attestation result privateKey = {private_key:?}");
+
+ let message = b"Hello from Service VM client";
+ info!("Signing message: {message:?}");
+ let signature = res.sign_message(message);
+ info!("Signature: {signature:?}");
}
-impl Drop for AttestationResult {
- fn drop(&mut self) {
- // SAFETY: This field is private, and only populated with a successful call to
- // `AVmPayload_requestAttestation`, and not freed elsewhere.
- unsafe { AVmAttestationResult_free(self.0.as_ptr()) };
+fn to_attestation_status(e: AttestationError) -> AttestationStatus {
+ match e {
+ AttestationError::InvalidChallenge => AttestationStatus::ERROR_INVALID_CHALLENGE,
+ AttestationError::AttestationFailed => AttestationStatus::ERROR_ATTESTATION_FAILED,
+ AttestationError::AttestationUnsupported => AttestationStatus::ERROR_UNSUPPORTED,
}
}
-
-fn get_certificate_count(res: &AVmAttestationResult) -> usize {
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed.
- unsafe { AVmAttestationResult_getCertificateCount(res) }
-}
-
-fn get_certificate_at(res: &AVmAttestationResult, index: usize) -> Result<Box<[u8]>> {
- let size =
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed.
- unsafe { AVmAttestationResult_getCertificateAt(res, index, ptr::null_mut(), 0) };
- let mut cert = vec![0u8; size];
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed. This function only writes within the bounds of `cert`.
- // And `cert` cannot overlap `res` because we just allocated it.
- let size = unsafe {
- AVmAttestationResult_getCertificateAt(
- res,
- index,
- cert.as_mut_ptr() as *mut c_void,
- cert.len(),
- )
- };
- ensure!(size == cert.len());
- Ok(cert.into_boxed_slice())
-}
-
-fn get_private_key(res: &AVmAttestationResult) -> Result<Box<[u8]>> {
- let size =
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed.
- unsafe { AVmAttestationResult_getPrivateKey(res, ptr::null_mut(), 0) };
- let mut private_key = vec![0u8; size];
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed. This function only writes within the bounds of `private_key`.
- // And `private_key` cannot overlap `res` because we just allocated it.
- let size = unsafe {
- AVmAttestationResult_getPrivateKey(
- res,
- private_key.as_mut_ptr() as *mut c_void,
- private_key.len(),
- )
- };
- ensure!(size == private_key.len());
- Ok(private_key.into_boxed_slice())
-}
-
-fn sign_with_attested_key(res: &AVmAttestationResult, message: &[u8]) -> Result<Vec<u8>> {
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed.
- let size = unsafe {
- AVmAttestationResult_sign(
- res,
- message.as_ptr() as *const c_void,
- message.len(),
- ptr::null_mut(),
- 0,
- )
- };
- let mut signature = vec![0u8; size];
- // SAFETY: The result is returned by `AVmPayload_requestAttestation` and should be valid
- // before getting freed. This function only writes within the bounds of `signature`.
- // And `signature` cannot overlap `res` because we just allocated it.
- let size = unsafe {
- AVmAttestationResult_sign(
- res,
- message.as_ptr() as *const c_void,
- message.len(),
- signature.as_mut_ptr() as *mut c_void,
- signature.len(),
- )
- };
- ensure!(size <= signature.len());
- signature.truncate(size);
- Ok(signature)
-}
-
-fn status_to_cstr(status: AVmAttestationStatus) -> &'static CStr {
- // SAFETY: The function only reads the given enum status and returns a pointer to a
- // static string.
- let message = unsafe { AVmAttestationStatus_toString(status) };
- // SAFETY: The pointer returned by `AVmAttestationStatus_toString` is guaranteed to
- // point to a valid C String that lives forever.
- unsafe { CStr::from_ptr(message) }
-}
diff --git a/vm_payload/Android.bp b/vm_payload/Android.bp
index 229f533..cf2a002 100644
--- a/vm_payload/Android.bp
+++ b/vm_payload/Android.bp
@@ -39,8 +39,8 @@
visibility: [":__subpackages__"],
}
-// Rust wrappers round the C API for Rust clients.
-// (Yes, this involves going Rust -> C -> Rust.)
+// Access to the C API for Rust code.
+// This shouldn't be used directly - prefer libvm_payload_rs (below)
rust_bindgen {
name: "libvm_payload_bindgen",
wrapper_src: "include-restricted/vm_payload_restricted.h",
@@ -51,15 +51,31 @@
bindgen_flags: [
"--default-enum-style rust",
],
- visibility: [
- "//packages/modules/Virtualization/compos",
- "//packages/modules/Virtualization/service_vm:__subpackages__",
- ],
shared_libs: [
"libvm_payload#current",
],
}
+// Wrapper library for the raw C API for use by Rust clients.
+// (Yes, this involves going Rust -> C -> Rust.)
+// This is not a stable API - we may change it in subsequent versions.
+// But it is made available as an rlib so it is linked into any
+// code using it, leaving only dependencies on stable APIs.
+// So code built with it should run unchanged on future versions.
+rust_library_rlib {
+ name: "libvm_payload_rs",
+ crate_name: "vm_payload",
+ defaults: ["avf_build_flags_rust"],
+ srcs: ["wrapper/lib.rs"],
+ rustlibs: [
+ "libbinder_rs",
+ "libstatic_assertions",
+ "libvm_payload_bindgen",
+ ],
+ apex_available: ["com.android.compos"],
+ visibility: ["//visibility:public"],
+}
+
// Shared library for clients to link against.
cc_library_shared {
name: "libvm_payload",
diff --git a/vm_payload/README.md b/vm_payload/README.md
index 4b1e6f3..66fd532 100644
--- a/vm_payload/README.md
+++ b/vm_payload/README.md
@@ -70,3 +70,16 @@
See [AIDL
backends](https://source.android.com/docs/core/architecture/aidl/aidl-backends)
for information on using AIDL with the NDK Binder from C++.
+
+## Rust
+
+A Rust wrapper library for the VM Payload API is available (as an rlib) for VM
+payloads written in Rust.
+
+This wrapper is not guaranteed to be stable; we may change it in future
+versions. But payload code built using it will depend only on the C VM Payload
+API and the NDK APIs that are available to the payload, so should run unchanged
+on future versions.
+
+See [wrapper/lib.rs](wrapper/lib.rs) and `libvm_payload_rs` in
+[Android.bp](Android.bp).
diff --git a/vm_payload/wrapper/attestation.rs b/vm_payload/wrapper/attestation.rs
new file mode 100644
index 0000000..e0055d5
--- /dev/null
+++ b/vm_payload/wrapper/attestation.rs
@@ -0,0 +1,288 @@
+/*
+ * Copyright 2024 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.
+ */
+
+use std::error::Error;
+use std::ffi::{c_void, CStr};
+use std::fmt::{self, Display};
+use std::iter::FusedIterator;
+use std::ptr::{self, NonNull};
+
+use vm_payload_bindgen::{
+ AVmAttestationResult, AVmAttestationResult_free, AVmAttestationResult_getCertificateAt,
+ AVmAttestationResult_getCertificateCount, AVmAttestationResult_getPrivateKey,
+ AVmAttestationResult_sign, AVmAttestationStatus, AVmAttestationStatus_toString,
+ AVmPayload_requestAttestation, AVmPayload_requestAttestationForTesting,
+};
+
+/// Holds the result of a successful Virtual Machine attestation request.
+/// See [`request_attestation`].
+#[derive(Debug)]
+pub struct AttestationResult {
+ result: NonNull<AVmAttestationResult>,
+}
+
+/// Error type that can be returned from an unsuccessful Virtual Machine attestation request.
+/// See [`request_attestation`].
+#[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
+pub enum AttestationError {
+ /// The challenge size was not between 0 and 64 bytes (inclusive).
+ InvalidChallenge,
+ /// The attempt to attest the VM failed. A subsequent request may succeed.
+ AttestationFailed,
+ /// VM attestation is not supported in the current environment.
+ AttestationUnsupported,
+}
+
+impl Error for AttestationError {}
+
+impl Display for AttestationError {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
+ let status = match self {
+ Self::InvalidChallenge => AVmAttestationStatus::ATTESTATION_ERROR_INVALID_CHALLENGE,
+ Self::AttestationFailed => AVmAttestationStatus::ATTESTATION_ERROR_ATTESTATION_FAILED,
+ Self::AttestationUnsupported => AVmAttestationStatus::ATTESTATION_ERROR_UNSUPPORTED,
+ };
+ // SAFETY: AVmAttestationStatus_toString always returns a non-null pointer to a
+ // nul-terminated C string with static lifetime (which is valid UTF-8).
+ let c_str = unsafe { CStr::from_ptr(AVmAttestationStatus_toString(status)) };
+ let str = c_str.to_str().expect("Invalid UTF-8 for AVmAttestationStatus");
+ f.write_str(str)
+ }
+}
+
+impl Drop for AttestationResult {
+ fn drop(&mut self) {
+ let ptr = self.result.as_ptr();
+
+ // SAFETY: The `result` field is private, and only populated with a successful call to
+ // `AVmPayload_requestAttestation`, and not freed elsewhere.
+ unsafe { AVmAttestationResult_free(ptr) };
+ }
+}
+
+// SAFETY: The API functions that accept the `AVmAttestationResult` pointer are all safe to call
+// from any thread, including `AVmAttestationResult_free` which is called only on drop.
+unsafe impl Send for AttestationResult {}
+
+// SAFETY: There is no interior mutation here; any future functions that might mutate the data would
+// require a non-const pointer and hence need `&mut self` here. The only existing such function is
+// `AVmAttestationResult_free` where we take a mutable reference guaranteeing no other references
+// exist. The raw API functions are safe to call from any thread.
+unsafe impl Sync for AttestationResult {}
+
+/// Requests the remote attestation of this VM.
+///
+/// On success the supplied [`challenge`] will be included in the certificate chain accessible from
+/// the [`AttestationResult`]; this can be used as proof of the freshness of the attestation.
+///
+/// The challenge should be no more than 64 bytes long or the request will fail.
+pub fn request_attestation(challenge: &[u8]) -> Result<AttestationResult, AttestationError> {
+ let mut result: *mut AVmAttestationResult = ptr::null_mut();
+ // SAFETY: We only read the challenge within its bounds and the function does not retain any
+ // reference to it.
+ let status = unsafe {
+ AVmPayload_requestAttestation(
+ challenge.as_ptr() as *const c_void,
+ challenge.len(),
+ &mut result,
+ )
+ };
+ AttestationResult::new(status, result)
+}
+
+/// A variant of [`request_attestation`] used for testing purposes. This should not be used by
+/// normal VMs, and is not available to app owned VMs.
+pub fn request_attestation_for_testing(
+ challenge: &[u8],
+) -> Result<AttestationResult, AttestationError> {
+ let mut result: *mut AVmAttestationResult = ptr::null_mut();
+ // SAFETY: We only read the challenge within its bounds and the function does not retain any
+ // reference to it.
+ let status = unsafe {
+ AVmPayload_requestAttestationForTesting(
+ challenge.as_ptr() as *const c_void,
+ challenge.len(),
+ &mut result,
+ )
+ };
+ AttestationResult::new(status, result)
+}
+
+impl AttestationResult {
+ fn new(
+ status: AVmAttestationStatus,
+ result: *mut AVmAttestationResult,
+ ) -> Result<AttestationResult, AttestationError> {
+ match status {
+ AVmAttestationStatus::ATTESTATION_ERROR_INVALID_CHALLENGE => {
+ Err(AttestationError::InvalidChallenge)
+ }
+ AVmAttestationStatus::ATTESTATION_ERROR_ATTESTATION_FAILED => {
+ Err(AttestationError::AttestationFailed)
+ }
+ AVmAttestationStatus::ATTESTATION_ERROR_UNSUPPORTED => {
+ Err(AttestationError::AttestationUnsupported)
+ }
+ AVmAttestationStatus::ATTESTATION_OK => {
+ let result = NonNull::new(result)
+ .expect("Attestation succeeded but the attestation result is null");
+ Ok(AttestationResult { result })
+ }
+ }
+ }
+
+ fn as_const_ptr(&self) -> *const AVmAttestationResult {
+ self.result.as_ptr().cast_const()
+ }
+
+ /// Returns the attested private key. This is the ECDSA P-256 private key corresponding to the
+ /// public key described by the leaf certificate in the attested
+ /// [certificate chain](AttestationResult::certificate_chain). It is a DER-encoded
+ /// `ECPrivateKey` structure as specified in
+ /// [RFC 5915 s3](https://datatracker.ietf.org/doc/html/rfc5915#section-3).
+ ///
+ /// Note: The [`sign_message`](AttestationResult::sign_message) method allows signing with the
+ /// key without retrieving it.
+ pub fn private_key(&self) -> Vec<u8> {
+ let ptr = self.as_const_ptr();
+
+ let size =
+ // SAFETY: We own the `AVmAttestationResult` pointer, so it is valid. The function
+ // writes no data since we pass a zero size, and null is explicitly allowed for the
+ // destination in that case.
+ unsafe { AVmAttestationResult_getPrivateKey(ptr, ptr::null_mut(), 0) };
+
+ let mut private_key = vec![0u8; size];
+ // SAFETY: We own the `AVmAttestationResult` pointer, so it is valid. The function only
+ // writes within the bounds of `private_key`, which we just allocated so cannot be aliased.
+ let size = unsafe {
+ AVmAttestationResult_getPrivateKey(
+ ptr,
+ private_key.as_mut_ptr() as *mut c_void,
+ private_key.len(),
+ )
+ };
+ assert_eq!(size, private_key.len());
+ private_key
+ }
+
+ /// Signs the given message using the attested private key. The signature uses ECDSA P-256; the
+ /// message is first hashed with SHA-256 and then it is signed with the attested EC P-256
+ /// [private key](AttestationResult::private_key).
+ ///
+ /// The signature is a DER-encoded `ECDSASignature`` structure as described in
+ /// [RFC 6979](https://datatracker.ietf.org/doc/html/rfc6979).
+ pub fn sign_message(&self, message: &[u8]) -> Vec<u8> {
+ let ptr = self.as_const_ptr();
+
+ // SAFETY: We own the `AVmAttestationResult` pointer, so it is valid. The function
+ // writes no data since we pass a zero size, and null is explicitly allowed for the
+ // destination in that case.
+ let size = unsafe {
+ AVmAttestationResult_sign(
+ ptr,
+ message.as_ptr() as *const c_void,
+ message.len(),
+ ptr::null_mut(),
+ 0,
+ )
+ };
+
+ let mut signature = vec![0u8; size];
+ // SAFETY: We own the `AVmAttestationResult` pointer, so it is valid. The function only
+ // writes within the bounds of `signature`, which we just allocated so cannot be aliased.
+ let size = unsafe {
+ AVmAttestationResult_sign(
+ ptr,
+ message.as_ptr() as *const c_void,
+ message.len(),
+ signature.as_mut_ptr() as *mut c_void,
+ signature.len(),
+ )
+ };
+ assert!(size <= signature.len());
+ signature.truncate(size);
+ signature
+ }
+
+ /// Returns an iterator over the certificates forming the certificate chain for the VM, and its
+ /// public key, obtained by the attestation process.
+ ///
+ /// The certificate chain consists of a sequence of DER-encoded X.509 certificates that form
+ /// the attestation key's certificate chain. It starts with the leaf certificate covering the
+ /// attested public key and ends with the root certificate.
+ pub fn certificate_chain(&self) -> CertIterator {
+ // SAFETY: We own the `AVmAttestationResult` pointer, so it is valid.
+ let count = unsafe { AVmAttestationResult_getCertificateCount(self.as_const_ptr()) };
+
+ CertIterator { result: self, count, current: 0 }
+ }
+
+ fn certificate(&self, index: usize) -> Vec<u8> {
+ let ptr = self.as_const_ptr();
+
+ let size =
+ // SAFETY: We own the `AVmAttestationResult` pointer, so it is valid. The function
+ // writes no data since we pass a zero size, and null is explicitly allowed for the
+ // destination in that case. The function will panic if `index` is out of range (which
+ // is safe).
+ unsafe { AVmAttestationResult_getCertificateAt(ptr, index, ptr::null_mut(), 0) };
+
+ let mut cert = vec![0u8; size];
+ // SAFETY: We own the `AVmAttestationResult` pointer, so it is valid. The function only
+ // writes within the bounds of `cert`, which we just allocated so cannot be aliased.
+ let size = unsafe {
+ AVmAttestationResult_getCertificateAt(
+ ptr,
+ index,
+ cert.as_mut_ptr() as *mut c_void,
+ cert.len(),
+ )
+ };
+ assert_eq!(size, cert.len());
+ cert
+ }
+}
+
+/// An iterator over the DER-encoded X.509 certificates containin in an [`AttestationResult`].
+/// See [`certificate_chain`](AttestationResult::certificate_chain) for more details.
+pub struct CertIterator<'a> {
+ result: &'a AttestationResult,
+ count: usize,
+ current: usize, // Invariant: current <= count
+}
+
+impl<'a> Iterator for CertIterator<'a> {
+ type Item = Vec<u8>;
+
+ fn next(&mut self) -> Option<Self::Item> {
+ if self.current < self.count {
+ let cert = self.result.certificate(self.current);
+ self.current += 1;
+ Some(cert)
+ } else {
+ None
+ }
+ }
+
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ let size = self.count - self.current;
+ (size, Some(size))
+ }
+}
+
+impl<'a> ExactSizeIterator for CertIterator<'a> {}
+impl<'a> FusedIterator for CertIterator<'a> {}
diff --git a/vm_payload/wrapper/lib.rs b/vm_payload/wrapper/lib.rs
new file mode 100644
index 0000000..bc26802
--- /dev/null
+++ b/vm_payload/wrapper/lib.rs
@@ -0,0 +1,188 @@
+/*
+ * Copyright 2024 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.
+ */
+
+//! Rust wrapper for the VM Payload API, allowing virtual machine payload code to be written in
+//! Rust. This wraps the raw C API, accessed via bindgen, into a more idiomatic Rust interface.
+//!
+//! See `https://cs.android.com/android/platform/superproject/main/+/main:packages/modules/Virtualization/vm_payload/README.md`
+//! for more information on the VM Payload API.
+
+mod attestation;
+
+pub use attestation::{
+ request_attestation, request_attestation_for_testing, AttestationError, AttestationResult,
+};
+use binder::unstable_api::AsNative;
+use binder::{FromIBinder, Strong};
+use std::ffi::{c_void, CStr, OsStr};
+use std::os::unix::ffi::OsStrExt;
+use std::path::Path;
+use std::ptr;
+use vm_payload_bindgen::{
+ AIBinder, AVmPayload_getApkContentsPath, AVmPayload_getEncryptedStoragePath,
+ AVmPayload_getVmInstanceSecret, AVmPayload_notifyPayloadReady, AVmPayload_runVsockRpcServer,
+};
+
+/// Marks the main function of the VM payload.
+///
+/// When the VM is run, this function is called. If it returns, the VM ends normally with a 0 exit
+/// code.
+///
+/// Example:
+///
+/// ```rust
+/// use log::info;
+///
+/// vm_payload::main!(vm_main);
+///
+/// fn vm_main() {
+/// android_logger::init_once(
+/// android_logger::Config::default()
+/// .with_tag("example_vm_payload")
+/// .with_max_level(log::LevelFilter::Info),
+/// );
+/// info!("Hello world");
+/// }
+/// ```
+#[macro_export]
+macro_rules! main {
+ ($name:path) => {
+ // Export a symbol with a name matching the extern declaration below.
+ #[export_name = "rust_main"]
+ fn __main() {
+ // Ensure that the main function provided by the application has the correct type.
+ $name()
+ }
+ };
+}
+
+// This is the real C entry point for the VM; we just forward to the Rust entry point.
+#[allow(non_snake_case)]
+#[no_mangle]
+extern "C" fn AVmPayload_main() {
+ extern "Rust" {
+ fn rust_main();
+ }
+
+ // SAFETY: rust_main is provided by the application using the `main!` macro above, which makes
+ // sure it has the right type.
+ unsafe { rust_main() }
+}
+
+/// Notifies the host that the payload is ready.
+///
+/// If the host app has set a `VirtualMachineCallback` for the VM, its
+/// `onPayloadReady` method will be called.
+///
+/// Note that subsequent calls to this function after the first have no effect;
+/// `onPayloadReady` is never called more than once.
+pub fn notify_payload_ready() {
+ // SAFETY: Invokes a method from the bindgen library `vm_payload_bindgen` which is safe to
+ // call at any time.
+ unsafe { AVmPayload_notifyPayloadReady() };
+}
+
+/// Runs a binder RPC server, serving the supplied binder service implementation on the given vsock
+/// port.
+///
+/// If and when the server is ready for connections (i.e. it is listening on the port),
+/// [`notify_payload_ready`] is called to notify the host that the server is ready. This is
+/// appropriate for VM payloads that serve a single binder service - which is common.
+///
+/// Note that this function does not return. The calling thread joins the binder
+/// thread pool to handle incoming messages.
+pub fn run_single_vsock_service<T>(service: Strong<T>, port: u32) -> !
+where
+ T: FromIBinder + ?Sized,
+{
+ extern "C" fn on_ready(_param: *mut c_void) {
+ notify_payload_ready();
+ }
+
+ let mut service = service.as_binder();
+ // The cast here is needed because the compiler doesn't know that our vm_payload_bindgen
+ // AIBinder is the same type as binder_ndk_sys::AIBinder.
+ let service = service.as_native_mut() as *mut AIBinder;
+ let param = ptr::null_mut();
+ // SAFETY: We have a strong reference to the service, so the raw pointer remains valid. It is
+ // safe for on_ready to be invoked at any time, with any parameter.
+ unsafe { AVmPayload_runVsockRpcServer(service, port, Some(on_ready), param) }
+}
+
+/// Gets the path to the contents of the APK containing the VM payload. It is a directory, under
+/// which are the unzipped contents of the APK containing the payload, all read-only
+/// but accessible to the payload.
+pub fn apk_contents_path() -> &'static Path {
+ // SAFETY: AVmPayload_getApkContentsPath always returns a non-null pointer to a
+ // nul-terminated C string with static lifetime.
+ let c_str = unsafe { CStr::from_ptr(AVmPayload_getApkContentsPath()) };
+ Path::new(OsStr::from_bytes(c_str.to_bytes()))
+}
+
+/// Gets the path to the encrypted persistent storage for the VM, if any. This is
+/// a directory under which any files or directories created will be stored on
+/// behalf of the VM by the host app. All data is encrypted using a key known
+/// only to the VM, so the host cannot decrypt it, but may delete it.
+///
+/// Returns `None` if no encrypted storage was requested in the VM configuration.
+pub fn encrypted_storage_path() -> Option<&'static Path> {
+ // SAFETY: AVmPayload_getEncryptedStoragePath returns either null or a pointer to a
+ // nul-terminated C string with static lifetime.
+ let ptr = unsafe { AVmPayload_getEncryptedStoragePath() };
+ if ptr.is_null() {
+ None
+ } else {
+ // SAFETY: We know the pointer is not null, and so it is a valid C string.
+ let c_str = unsafe { CStr::from_ptr(ptr) };
+ Some(Path::new(OsStr::from_bytes(c_str.to_bytes())))
+ }
+}
+
+/// Retrieves all or part of a 32-byte secret that is bound to this unique VM
+/// instance and the supplied identifier. The secret can be used e.g. as an
+/// encryption key.
+///
+/// Every VM has a secret that is derived from a device-specific value known to
+/// the hypervisor, the code that runs in the VM and its non-modifiable
+/// configuration; it is not made available to the host OS.
+///
+/// This function performs a further derivation from the VM secret and the
+/// supplied identifier. As long as the VM identity doesn't change the same value
+/// will be returned for the same identifier, even if the VM is stopped &
+/// restarted or the device rebooted.
+///
+/// If multiple secrets are required for different purposes, a different
+/// identifier should be used for each. The identifiers otherwise are arbitrary
+/// byte sequences and do not need to be kept secret; typically they are
+/// hardcoded in the calling code.
+///
+/// The secret is returned in [`secret`], truncated to its size, which must be between
+/// 1 and 32 bytes (inclusive) or the function will panic.
+pub fn get_vm_instance_secret<const N: usize>(identifier: &[u8], secret: &mut [u8]) {
+ let secret_size = secret.len();
+ assert!((1..=32).contains(&secret_size), "VM instance secrets can be up to 32 bytes long");
+
+ // SAFETY: The function only reads from `[identifier]` within its bounds, and only writes to
+ // `[secret]` within its bounds. Neither reference is retained, and we know neither is null.
+ unsafe {
+ AVmPayload_getVmInstanceSecret(
+ identifier.as_ptr() as *const c_void,
+ identifier.len(),
+ secret.as_mut_ptr() as *mut c_void,
+ secret_size,
+ )
+ }
+}