VM: Introduce writePayloadRpData/readPayloadRpData

VM payload require an api to allow storing n bytes' data with
confidentialty & tamper evidence integrity guarantees.

Microdroid Manager implements this using the vm_secret module, which
uses the payload's DICE chain to store/get secret from Secretkeeper.

Additionally introduce a test that uses these api.
Test: #rollbackProtectedDataOfPayload
Bug: 378911776

Change-Id: Id39f5c6c626531029bf33ef5d28dc237881e40e6
diff --git a/guest/microdroid_manager/aidl/android/system/virtualization/payload/IVmPayloadService.aidl b/guest/microdroid_manager/aidl/android/system/virtualization/payload/IVmPayloadService.aidl
index b7a539b..30c4299 100644
--- a/guest/microdroid_manager/aidl/android/system/virtualization/payload/IVmPayloadService.aidl
+++ b/guest/microdroid_manager/aidl/android/system/virtualization/payload/IVmPayloadService.aidl
@@ -78,6 +78,20 @@
     byte[] getVmInstanceSecret(in byte[] identifier, int size);
 
     /**
+     * Write `data`, on behalf of the client, to Secretkeeper.
+     * This is confidential to the pVM and protected via appropriate DICE policy
+     * on the payload's DICE chain.
+     */
+    void writePayloadRpData(in byte[32] data);
+
+    /**
+     * Read payload's `data` written on behalf of the payload in Secretkeeper.
+     * The returned value can be null either due to no value written or because
+     * Android maliciously deleted the value - Secretkeeper deletion are not authenticated.
+     */
+    @nullable byte[32] readPayloadRpData();
+
+    /**
      * Gets the DICE attestation chain for the VM.
      *
      * The DICE chain must not be made available to all VMs as it contains privacy breaking
diff --git a/guest/microdroid_manager/src/vm_payload_service.rs b/guest/microdroid_manager/src/vm_payload_service.rs
index 7f4317b..c4a9111 100644
--- a/guest/microdroid_manager/src/vm_payload_service.rs
+++ b/guest/microdroid_manager/src/vm_payload_service.rs
@@ -97,6 +97,25 @@
             certificateChain: cert_chain,
         })
     }
+
+    fn readPayloadRpData(&self) -> binder::Result<Option<[u8; 32]>> {
+        let data = self
+            .secret
+            .read_payload_data_rp()
+            .context("Failed to read payload's rollback protected data")
+            .with_log()
+            .or_service_specific_exception(-1)?;
+        Ok(data)
+    }
+
+    fn writePayloadRpData(&self, data: &[u8; 32]) -> binder::Result<()> {
+        self.secret
+            .write_payload_data_rp(data)
+            .context("Failed to write payload's rollback protected data")
+            .with_log()
+            .or_service_specific_exception(-1)?;
+        Ok(())
+    }
 }
 
 impl Interface for VmPayloadService {}
diff --git a/guest/microdroid_manager/src/vm_secret.rs b/guest/microdroid_manager/src/vm_secret.rs
index 5cc90ff..04d6817 100644
--- a/guest/microdroid_manager/src/vm_secret.rs
+++ b/guest/microdroid_manager/src/vm_secret.rs
@@ -71,13 +71,20 @@
     // with downgraded images will not have access to VM's secret.
     // V2 secrets require hardware support - Secretkeeper HAL, which (among other things)
     // is backed by tamper-evident storage, providing rollback protection to these secrets.
-    V2 { dice_artifacts: OwnedDiceArtifactsWithExplicitKey, skp_secret: ZVec },
+    V2 {
+        instance_id: [u8; ID_SIZE],
+        dice_artifacts: OwnedDiceArtifactsWithExplicitKey,
+        skp_secret: ZVec,
+        secretkeeper_session: SkVmSession,
+    },
     // V1 secrets are not protected against rollback of boot images.
     // They are reliable only if rollback of images was prevented by verified boot ie,
     // each stage (including pvmfw/Microdroid/Microdroid Manager) prevents downgrade of next
     // stage. These are now legacy secrets & used only when Secretkeeper HAL is not supported
     // by device.
-    V1 { dice_artifacts: OwnedDiceArtifacts },
+    V1 {
+        dice_artifacts: OwnedDiceArtifacts,
+    },
 }
 
 // For supporting V2 secrets, guest expects the public key to be present in the Linux device tree.
@@ -100,24 +107,26 @@
 
         let explicit_dice = OwnedDiceArtifactsWithExplicitKey::from_owned_artifacts(dice_artifacts)
             .context("Failed to get Dice artifacts in explicit key format")?;
-        let session = SkVmSession::new(vm_service, &explicit_dice)?;
         let id = super::get_instance_id()?.ok_or(anyhow!("Missing instance_id"))?;
         let explicit_dice_chain = explicit_dice
             .explicit_key_dice_chain()
             .ok_or(anyhow!("Missing explicit dice chain, this is unusual"))?;
         let policy = sealing_policy(explicit_dice_chain)
             .map_err(|e| anyhow!("Failed to build a sealing_policy: {e}"))?;
+        let session = SkVmSession::new(vm_service, &explicit_dice, policy)?;
         let mut skp_secret = Zeroizing::new([0u8; SECRET_SIZE]);
-        if let Some(secret) = session.get_secret(id, Some(policy.clone()))? {
+        if let Some(secret) = session.get_secret(id)? {
             *skp_secret = secret
         } else {
             log::warn!("No entry found in Secretkeeper for this VM instance, creating new secret.");
             *skp_secret = rand::random();
-            session.store_secret(id, skp_secret.clone(), policy)?;
+            session.store_secret(id, skp_secret.clone())?;
         }
         Ok(Self::V2 {
+            instance_id: id,
             dice_artifacts: explicit_dice,
             skp_secret: ZVec::try_from(skp_secret.to_vec())?,
+            secretkeeper_session: session,
         })
     }
 
@@ -130,7 +139,7 @@
 
     fn get_vm_secret(&self, salt: &[u8], identifier: &[u8], key: &mut [u8]) -> Result<()> {
         match self {
-            Self::V2 { dice_artifacts, skp_secret } => {
+            Self::V2 { dice_artifacts, skp_secret, .. } => {
                 let mut hasher = sha::Sha256::new();
                 hasher.update(dice_artifacts.cdi_seal());
                 hasher.update(skp_secret);
@@ -152,6 +161,23 @@
     pub fn derive_encryptedstore_key(&self, key: &mut [u8]) -> Result<()> {
         self.get_vm_secret(SALT_ENCRYPTED_STORE, ENCRYPTEDSTORE_KEY_IDENTIFIER.as_bytes(), key)
     }
+
+    pub fn read_payload_data_rp(&self) -> Result<Option<[u8; SECRET_SIZE]>> {
+        let Self::V2 { instance_id, secretkeeper_session, .. } = self else {
+            return Err(anyhow!("Rollback protected data is not available with V1 secrets"));
+        };
+        let payload_id = sha::sha512(instance_id);
+        secretkeeper_session.get_secret(payload_id)
+    }
+
+    pub fn write_payload_data_rp(&self, data: &[u8; SECRET_SIZE]) -> Result<()> {
+        let data = Zeroizing::new(*data);
+        let Self::V2 { instance_id, secretkeeper_session, .. } = self else {
+            return Err(anyhow!("Rollback protected data is not available with V1 secrets"));
+        };
+        let payload_id = sha::sha512(instance_id);
+        secretkeeper_session.store_secret(payload_id, data)
+    }
 }
 
 // Construct a sealing policy on the dice chain. VMs uses the following set of constraint for
@@ -227,31 +253,35 @@
 }
 
 // The secure session between VM & Secretkeeper
-struct SkVmSession(Arc<Mutex<SkSession>>);
+pub(crate) struct SkVmSession {
+    session: Arc<Mutex<SkSession>>,
+    sealing_policy: Vec<u8>,
+}
+
+// TODO(b/378911776): This get_secret/store_secret fails on expired session.
+// Introduce retry after refreshing the session
 impl SkVmSession {
     fn new(
         vm_service: &Strong<dyn IVirtualMachineService>,
         dice: &OwnedDiceArtifactsWithExplicitKey,
+        sealing_policy: Vec<u8>,
     ) -> Result<Self> {
         let secretkeeper_proxy = get_secretkeeper_service(vm_service)?;
-        let secure_session =
-            SkSession::new(secretkeeper_proxy, dice, Some(get_secretkeeper_identity()?))?;
-        let secure_session = Arc::new(Mutex::new(secure_session));
-        Ok(Self(secure_session))
+        let session = SkSession::new(secretkeeper_proxy, dice, Some(get_secretkeeper_identity()?))?;
+        let session = Arc::new(Mutex::new(session));
+        Ok(Self { session, sealing_policy })
     }
 
-    fn store_secret(
-        &self,
-        id: [u8; ID_SIZE],
-        secret: Zeroizing<[u8; SECRET_SIZE]>,
-        sealing_policy: Vec<u8>,
-    ) -> Result<()> {
-        let store_request =
-            StoreSecretRequest { id: Id(id), secret: Secret(*secret), sealing_policy };
+    fn store_secret(&self, id: [u8; ID_SIZE], secret: Zeroizing<[u8; SECRET_SIZE]>) -> Result<()> {
+        let store_request = StoreSecretRequest {
+            id: Id(id),
+            secret: Secret(*secret),
+            sealing_policy: self.sealing_policy.clone(),
+        };
         log::info!("Secretkeeper operation: {:?}", store_request);
 
         let store_request = store_request.serialize_to_packet().to_vec().map_err(anyhow_err)?;
-        let session = &mut *self.0.lock().unwrap();
+        let session = &mut *self.session.lock().unwrap();
         let store_response = session.secret_management_request(&store_request)?;
         let store_response = ResponsePacket::from_slice(&store_response).map_err(anyhow_err)?;
         let response_type = store_response.response_type().map_err(anyhow_err)?;
@@ -263,15 +293,14 @@
         Ok(())
     }
 
-    fn get_secret(
-        &self,
-        id: [u8; ID_SIZE],
-        updated_sealing_policy: Option<Vec<u8>>,
-    ) -> Result<Option<[u8; SECRET_SIZE]>> {
-        let get_request = GetSecretRequest { id: Id(id), updated_sealing_policy };
+    fn get_secret(&self, id: [u8; ID_SIZE]) -> Result<Option<[u8; SECRET_SIZE]>> {
+        let get_request = GetSecretRequest {
+            id: Id(id),
+            updated_sealing_policy: Some(self.sealing_policy.clone()),
+        };
         log::info!("Secretkeeper operation: {:?}", get_request);
         let get_request = get_request.serialize_to_packet().to_vec().map_err(anyhow_err)?;
-        let session = &mut *self.0.lock().unwrap();
+        let session = &mut *self.session.lock().unwrap();
         let get_response = session.secret_management_request(&get_request)?;
         let get_response = ResponsePacket::from_slice(&get_response).map_err(anyhow_err)?;
         let response_type = get_response.response_type().map_err(anyhow_err)?;
diff --git a/libs/libvm_payload/Android.bp b/libs/libvm_payload/Android.bp
index bb91737..1ebbe39 100644
--- a/libs/libvm_payload/Android.bp
+++ b/libs/libvm_payload/Android.bp
@@ -34,6 +34,7 @@
     bindgen_flags: [
         "--default-enum-style rust",
         "--allowlist-type=AVmAttestationStatus",
+        "--allowlist-type=AVmAccessRollbackProtectedSecretStatus",
     ],
     visibility: [":__subpackages__"],
 }
diff --git a/libs/libvm_payload/include/vm_payload.h b/libs/libvm_payload/include/vm_payload.h
index 5e15607..43fba82 100644
--- a/libs/libvm_payload/include/vm_payload.h
+++ b/libs/libvm_payload/include/vm_payload.h
@@ -52,6 +52,22 @@
 } AVmAttestationStatus;
 
 /**
+ * Introduced in API 36.
+ * Status type used to indicate error while accessing RollbackProtectedSecret.
+ */
+typedef enum AVmAccessRollbackProtectedSecretStatus : int32_t {
+    /**
+     * Relevant Entry not found. This can happen either due to no value was ever written or because
+     * Android maliciously deleted the value (deletions may not be authenticated).
+     */
+    AVMACCESSROLLBACKPROTECTEDSECRETSTATUS_ENTRY_NOT_FOUND = -1,
+    /** Requested access size is not supported by the implementation */
+    AVMACCESSROLLBACKPROTECTEDSECRETSTATUS_BAD_SIZE = -2,
+    /** Access failed, this could be due to lacking support from Hardware */
+    AVMACCESSROLLBACKPROTECTEDSECRETSTATUS_ACCESS_FAILED = -3,
+} AVmAccessRollbackProtectedSecretStatus;
+
+/**
  * Notifies the host that the payload is ready.
  *
  * If the host app has set a `VirtualMachineCallback` for the VM, its
@@ -259,5 +275,33 @@
 size_t AVmAttestationResult_getCertificateAt(const AVmAttestationResult* _Nonnull result,
                                              size_t index, void* _Nullable data, size_t size)
         __INTRODUCED_IN(__ANDROID_API_V__);
+/**
+ * Writes up to n bytes from buffer starting at `buf`, on behalf of the payload, to rollback
+ * detectable storage. The number of bytes written may be less than n if, for example, the
+ * underlying storage has size constraints. This stored data is confidential to the pVM and
+ * protected via appropriate DICE policy on the payload's DICE chain.
+ *
+ * \param buf A pointer to data to be written. This should have the size of at least n bytes.
+ * \param n The maximum number of bytes to be filled in `buf`.
+ *
+ *  \return On success, the number of bytes written is returned. On error, appropriate
+ * AVmAccessRollbackProtectedSecretStatus (negative number) is returned.
+ */
+
+int32_t AVmPayload_writeRollbackProtectedSecret(const void* _Nonnull buf, size_t n)
+        __INTRODUCED_IN(36);
+/**
+ * Read up to n bytes of payload's data in rollback detectable storage into `buf`.
+ *
+ * \param buf A pointer to buffer where the requested data is written. This should have the size of
+ * at least n bytes.
+ * \param n The maximum number of bytes to be read.
+ *
+ *  \return On success, the number of bytes that would have been written to `buf` if n was
+ * sufficiently large. On error, appropriate AVmAccessRollbackProtectedSecretStatus(a negative
+ * number) is returned.
+ */
+int32_t AVmPayload_readRollbackProtectedSecret(void* _Nullable buf, size_t n) __INTRODUCED_IN(36);
+;
 
 __END_DECLS
diff --git a/libs/libvm_payload/libvm_payload.map.txt b/libs/libvm_payload/libvm_payload.map.txt
index 3daad00..0c6b56d 100644
--- a/libs/libvm_payload/libvm_payload.map.txt
+++ b/libs/libvm_payload/libvm_payload.map.txt
@@ -15,6 +15,8 @@
     AVmAttestationStatus_toString;       # systemapi introduced=VanillaIceCream
     AVmAttestationResult_getCertificateCount; # systemapi introduced=VanillaIceCream
     AVmAttestationResult_getCertificateAt; # systemapi introduced=VanillaIceCream
+    AVmPayload_writeRollbackProtectedSecret; # systemapi introduced=36
+    AVmPayload_readRollbackProtectedSecret; # systemapi introduced=36
   local:
     *;
 };
diff --git a/libs/libvm_payload/src/lib.rs b/libs/libvm_payload/src/lib.rs
index eb81752..29b0cbd 100644
--- a/libs/libvm_payload/src/lib.rs
+++ b/libs/libvm_payload/src/lib.rs
@@ -16,14 +16,14 @@
 
 use android_system_virtualization_payload::aidl::android::system::virtualization::payload:: IVmPayloadService::{
     IVmPayloadService, ENCRYPTEDSTORE_MOUNTPOINT, VM_APK_CONTENTS_PATH,
-    VM_PAYLOAD_SERVICE_SOCKET_NAME, AttestationResult::AttestationResult,
+    VM_PAYLOAD_SERVICE_SOCKET_NAME, AttestationResult::AttestationResult
 };
 use anyhow::{bail, ensure, Context, Result};
 use binder::{
     unstable_api::{new_spibinder, AIBinder},
     Strong, ExceptionCode,
 };
-use log::{error, info, LevelFilter};
+use log::{error, info, LevelFilter, debug};
 use rpcbinder::{RpcServer, RpcSession};
 use openssl::{ec::EcKey, sha::sha256, ecdsa::EcdsaSig};
 use std::convert::Infallible;
@@ -38,9 +38,12 @@
     Mutex,
 };
 use vm_payload_status_bindgen::AVmAttestationStatus;
+use vm_payload_status_bindgen::AVmAccessRollbackProtectedSecretStatus::{AVMACCESSROLLBACKPROTECTEDSECRETSTATUS_ENTRY_NOT_FOUND, AVMACCESSROLLBACKPROTECTEDSECRETSTATUS_ACCESS_FAILED, AVMACCESSROLLBACKPROTECTEDSECRETSTATUS_BAD_SIZE};
+use std::cmp::min;
 
 /// Maximum size of an ECDSA signature for EC P-256 key is 72 bytes.
 const MAX_ECDSA_P256_SIGNATURE_SIZE: usize = 72;
+const RP_DATA_SIZE: usize = 32;
 
 static VM_APK_CONTENTS_PATH_C: LazyLock<CString> =
     LazyLock::new(|| CString::new(VM_APK_CONTENTS_PATH).expect("CString::new failed"));
@@ -566,3 +569,86 @@
         ptr::null()
     }
 }
+
+/// Writes up to n bytes from buffer starting at `buf`, on behalf of the payload, to rollback
+/// detectable storage and return the number of bytes written or appropriate (negative) status.
+/// For this implementation, the backing storage is Secretkeeper HAL, which allows storing & reading
+/// of 32 bytes secret!
+///
+/// # Safety
+///
+/// Behavior is undefined if any of the following conditions are violated:
+///
+/// * `buf` must be [valid] for reads of n bytes.
+///
+/// [valid]: ptr#safety
+#[no_mangle]
+pub unsafe extern "C" fn AVmPayload_writeRollbackProtectedSecret(buf: *const u8, n: usize) -> i32 {
+    initialize_logging();
+    if n < RP_DATA_SIZE {
+        error!(
+            "Requested writing {} bytes, while Secretkeeper supports only {} bytes",
+            n, RP_DATA_SIZE
+        );
+        return AVMACCESSROLLBACKPROTECTEDSECRETSTATUS_BAD_SIZE as i32;
+    }
+    // Safety: See the requirements on `buf` above and we just checked that n >= RP_DATA_SIZE.
+    let buf = unsafe { std::slice::from_raw_parts(buf, RP_DATA_SIZE) };
+    match try_writing_payload_rollback_protected_data(buf.try_into().unwrap()) {
+        Ok(()) => RP_DATA_SIZE as i32,
+        Err(e) => {
+            error!("Failed to write rollback protected data: {e:?}");
+            AVMACCESSROLLBACKPROTECTEDSECRETSTATUS_ACCESS_FAILED as i32
+        }
+    }
+}
+
+/// Read up to n bytes of payload's data in rollback detectable storage into `buf`.
+/// For this implementation, the backing storage is Secretkeeper HAL, which allows storing & reading
+/// of 32 bytes secret!
+///
+/// # Safety
+///
+/// Behavior is undefined if any of the following conditions are violated:
+///
+/// * `buf` must be [valid] for writes of n bytes.
+///
+/// [valid]: ptr#safety
+#[no_mangle]
+pub unsafe extern "C" fn AVmPayload_readRollbackProtectedSecret(buf: *mut u8, n: usize) -> i32 {
+    initialize_logging();
+    match try_read_rollback_protected_data() {
+        Err(e) => {
+            error!("Failed to read rollback protected data: {e:?}");
+            AVMACCESSROLLBACKPROTECTEDSECRETSTATUS_ACCESS_FAILED as i32
+        }
+        Ok(stored_data) => {
+            if let Some(stored_data) = stored_data {
+                // SAFETY: See the requirements on `buf` above; `stored_data` is known to have
+                // length `RP_DATA_SIZE`, and cannot overlap `data` because we just allocated
+                // it.
+                unsafe {
+                    ptr::copy_nonoverlapping(stored_data.as_ptr(), buf, min(n, RP_DATA_SIZE));
+                }
+                RP_DATA_SIZE as i32
+            } else {
+                debug!("No relevant entry found in Secretkeeper");
+                AVMACCESSROLLBACKPROTECTEDSECRETSTATUS_ENTRY_NOT_FOUND as i32
+            }
+        }
+    }
+}
+
+fn try_writing_payload_rollback_protected_data(data: &[u8; RP_DATA_SIZE]) -> Result<()> {
+    get_vm_payload_service()?
+        .writePayloadRpData(data)
+        .context("Failed to write payload rollback protected data")?;
+    Ok(())
+}
+
+fn try_read_rollback_protected_data() -> Result<Option<[u8; RP_DATA_SIZE]>> {
+    let rp = get_vm_payload_service()?
+        .readPayloadRpData()
+        .context("Failed to read rollback protected data")?;
+    Ok(rp)
+}
diff --git a/libs/libvm_payload/wrapper/lib.rs b/libs/libvm_payload/wrapper/lib.rs
index b9ce6c8..133b14e 100644
--- a/libs/libvm_payload/wrapper/lib.rs
+++ b/libs/libvm_payload/wrapper/lib.rs
@@ -31,7 +31,9 @@
 use std::ptr;
 use vm_payload_bindgen::{
     AIBinder, AVmPayload_getApkContentsPath, AVmPayload_getEncryptedStoragePath,
-    AVmPayload_getVmInstanceSecret, AVmPayload_notifyPayloadReady, AVmPayload_runVsockRpcServer,
+    AVmPayload_getVmInstanceSecret, AVmPayload_notifyPayloadReady,
+    AVmPayload_readRollbackProtectedSecret, AVmPayload_runVsockRpcServer,
+    AVmPayload_writeRollbackProtectedSecret,
 };
 
 /// The functions declared here are restricted to VMs created with a config file;
@@ -194,3 +196,15 @@
         )
     }
 }
+
+/// Read payload's `data` written on behalf of the payload in Secretkeeper.
+pub fn read_rollback_protected_secret(data: &mut [u8]) -> i32 {
+    // SAFETY: The function only reads from`[data]` within its bounds.
+    unsafe { AVmPayload_readRollbackProtectedSecret(data.as_ptr() as *mut c_void, data.len()) }
+}
+
+/// Write `data`, on behalf of the payload, to Secretkeeper.
+pub fn write_rollback_protected_secret(data: &[u8]) -> i32 {
+    // SAFETY: The function only writes to `[data]` within its bounds.
+    unsafe { AVmPayload_writeRollbackProtectedSecret(data.as_ptr() as *const c_void, data.len()) }
+}
diff --git a/tests/aidl/com/android/microdroid/testservice/ITestService.aidl b/tests/aidl/com/android/microdroid/testservice/ITestService.aidl
index 6a3bc1b..73e5c5c 100644
--- a/tests/aidl/com/android/microdroid/testservice/ITestService.aidl
+++ b/tests/aidl/com/android/microdroid/testservice/ITestService.aidl
@@ -80,6 +80,19 @@
     String readLineFromConsole();
 
     /**
+     * Read payload's rollback protected data. The `AVmAccessRollbackProtectedSecretStatus` is
+     * wrapped as service_specific error in case of failure. This is _only_ used for testing.
+     */
+    byte[32] insecurelyReadPayloadRpData();
+
+    /**
+     * Request VM to write payload's rollback protected data. The
+     * `AVmAccessRollbackProtectedSecretStatus` is wrapped as service_specific error in case of
+     * failure. This is _only_ used for testing.
+     */
+    void insecurelyWritePayloadRpData(in byte[32] data);
+
+    /**
      * Request the service to exit, triggering the termination of the VM. This may cause any
      * requests in flight to fail.
      */
diff --git a/tests/helper/src/java/com/android/microdroid/test/device/MicrodroidDeviceTestBase.java b/tests/helper/src/java/com/android/microdroid/test/device/MicrodroidDeviceTestBase.java
index 2986bdc..3dbc242 100644
--- a/tests/helper/src/java/com/android/microdroid/test/device/MicrodroidDeviceTestBase.java
+++ b/tests/helper/src/java/com/android/microdroid/test/device/MicrodroidDeviceTestBase.java
@@ -272,9 +272,11 @@
     }
 
     protected void assumeNoUpdatableVmSupport() throws VirtualMachineException {
-        assume().withMessage("Secretkeeper not supported")
-                .that(getVirtualMachineManager().isUpdatableVmSupported())
-                .isFalse();
+        assume().withMessage("Secretkeeper not supported").that(isUpdatableVmSupported()).isFalse();
+    }
+
+    protected boolean isUpdatableVmSupported() throws VirtualMachineException {
+        return getVirtualMachineManager().isUpdatableVmSupported();
     }
 
     public abstract static class VmEventListener implements VirtualMachineCallback {
@@ -588,6 +590,7 @@
         public String mConsoleInput;
         public byte[] mInstanceSecret;
         public int mPageSize;
+        public byte[] mPayloadRpData;
 
         public void assertNoException() {
             if (mException != null) {
diff --git a/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java b/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
index 97a5e78..35ee7dd 100644
--- a/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
+++ b/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
@@ -1826,6 +1826,79 @@
         assertThat(testResults.mFileContent).isEqualTo(EXAMPLE_STRING);
     }
 
+    private boolean deviceCapableOfProtectedVm() {
+        int capabilities = getVirtualMachineManager().getCapabilities();
+        if ((capabilities & CAPABILITY_PROTECTED_VM) != 0) {
+            return true;
+        }
+        return false;
+    }
+
+    private void ensureUpdatableVmSupported() throws Exception {
+        if (getVendorApiLevel() >= 202504 && deviceCapableOfProtectedVm()) {
+            assertTrue(
+                    "Missing Updatable VM support, have you declared Secretkeeper interface?",
+                    isUpdatableVmSupported());
+        } else {
+            assumeTrue("Device does not support Updatable VM", isUpdatableVmSupported());
+        }
+    }
+
+    @Test
+    public void rollbackProtectedDataOfPayload() throws Exception {
+        assumeSupportedDevice();
+        // Rollback protected data is only possible if Updatable VMs is supported -
+        // which implies Secretkeeper support.
+        ensureUpdatableVmSupported();
+        byte[] value1 = new byte[32];
+        Arrays.fill(value1, (byte) 0xcc);
+        byte[] value2 = new byte[32];
+        Arrays.fill(value2, (byte) 0xdd);
+
+        VirtualMachineConfig config =
+                newVmConfigBuilderWithPayloadBinary("MicrodroidTestNativeLib.so")
+                        .setMemoryBytes(minMemoryRequired())
+                        .setEncryptedStorageBytes(ENCRYPTED_STORAGE_BYTES)
+                        .setDebugLevel(DEBUG_LEVEL_FULL)
+                        .build();
+        VirtualMachine vm = forceCreateNewVirtualMachine("test_vm", config);
+        TestResults testResults =
+                runVmTestService(
+                        TAG,
+                        vm,
+                        (ts, tr) -> {
+                            tr.mPayloadRpData = ts.insecurelyReadPayloadRpData();
+                        });
+        // ainsecurelyReadPayloadRpData()` must've failed since no data was ever written!
+        assertWithMessage("The read (unexpectedly) succeeded!")
+                .that(testResults.mException)
+                .isNotNull();
+
+        // Re-run the same VM & write/read th RP data & verify it what we just wrote!
+        testResults =
+                runVmTestService(
+                        TAG,
+                        vm,
+                        (ts, tr) -> {
+                            ts.insecurelyWritePayloadRpData(value1);
+                            tr.mPayloadRpData = ts.insecurelyReadPayloadRpData();
+                            ts.insecurelyWritePayloadRpData(value2);
+                        });
+        testResults.assertNoException();
+        assertThat(testResults.mPayloadRpData).isEqualTo(value1);
+
+        // Re-run the same VM again
+        testResults =
+                runVmTestService(
+                        TAG,
+                        vm,
+                        (ts, tr) -> {
+                            tr.mPayloadRpData = ts.insecurelyReadPayloadRpData();
+                        });
+        testResults.assertNoException();
+        assertThat(testResults.mPayloadRpData).isEqualTo(value2);
+    }
+
     @Test
     @CddTest(requirements = {"9.17/C-1-1", "9.17/C-2-1"})
     public void canReadFileFromAssets_debugFull() throws Exception {
diff --git a/tests/testapk/src/native/testbinary.cpp b/tests/testapk/src/native/testbinary.cpp
index 632f648..a1739f9 100644
--- a/tests/testapk/src/native/testbinary.cpp
+++ b/tests/testapk/src/native/testbinary.cpp
@@ -344,6 +344,23 @@
             return ScopedAStatus::ok();
         }
 
+        ScopedAStatus insecurelyReadPayloadRpData(std::array<uint8_t, 32>* out) override {
+            int32_t ret = AVmPayload_readRollbackProtectedSecret(out->data(), 32);
+            if (ret != 32) {
+                return ScopedAStatus::fromServiceSpecificError(ret);
+            }
+            return ScopedAStatus::ok();
+        }
+
+        ScopedAStatus insecurelyWritePayloadRpData(
+                const std::array<uint8_t, 32>& inputData) override {
+            int32_t ret = AVmPayload_writeRollbackProtectedSecret(inputData.data(), 32);
+            if (ret != 32) {
+                return ScopedAStatus::fromServiceSpecificError(ret);
+            }
+            return ScopedAStatus::ok();
+        }
+
         ScopedAStatus quit() override { exit(0); }
     };
     auto testService = ndk::SharedRefBase::make<TestService>();
diff --git a/tests/testapk/src/native/testbinary.rs b/tests/testapk/src/native/testbinary.rs
index e479342..2b2fa28 100644
--- a/tests/testapk/src/native/testbinary.rs
+++ b/tests/testapk/src/native/testbinary.rs
@@ -132,6 +132,12 @@
     fn readLineFromConsole(&self) -> BinderResult<String> {
         unimplemented()
     }
+    fn insecurelyReadPayloadRpData(&self) -> BinderResult<[u8; 32]> {
+        unimplemented()
+    }
+    fn insecurelyWritePayloadRpData(&self, _: &[u8; 32]) -> BinderResult<()> {
+        unimplemented()
+    }
 }
 
 fn unimplemented<T>() -> BinderResult<T> {
diff --git a/tests/vmshareapp/src/java/com/android/microdroid/test/sharevm/VmShareServiceImpl.java b/tests/vmshareapp/src/java/com/android/microdroid/test/sharevm/VmShareServiceImpl.java
index 13b0c51..4465c5e 100644
--- a/tests/vmshareapp/src/java/com/android/microdroid/test/sharevm/VmShareServiceImpl.java
+++ b/tests/vmshareapp/src/java/com/android/microdroid/test/sharevm/VmShareServiceImpl.java
@@ -276,5 +276,15 @@
         public void quit() throws RemoteException {
             throw new UnsupportedOperationException("Not supported");
         }
+
+        @Override
+        public byte[] insecurelyReadPayloadRpData() {
+            throw new UnsupportedOperationException("Not supported");
+        }
+
+        @Override
+        public void insecurelyWritePayloadRpData(byte[] data) {
+            throw new UnsupportedOperationException("Not supported");
+        }
     }
 }