Integrate Android biometrics with the shared Rust lease (#98)

crates/storage/src/authentication.rs

@@ -310,14 +310,18 @@ impl<B: SecretStoreBackend, C: AuthenticationClock> AuthenticationSession<B, C>
 
     /// Revoke every outstanding handle immediately.
     pub fn manual_lock(&self) -> Result<(), AuthenticationError> {
+        let interrupted = self.shared.store.cancel_pending();
         let _operation = self.shared.operation()?;
-        self.shared.revoke(RevocationReason::Manual)
+        self.shared.revoke(RevocationReason::Manual)?;
+        interrupted.map_err(Into::into)
     }
 
     /// Cancel authentication and revoke any lease created by the pending interaction.
     pub fn cancel(&self) -> Result<(), AuthenticationError> {
+        let interrupted = self.shared.store.cancel_pending();
         let _operation = self.shared.operation()?;
-        self.shared.revoke(RevocationReason::Cancelled)
+        self.shared.revoke(RevocationReason::Cancelled)?;
+        interrupted.map_err(Into::into)
     }
 
     /// Apply a new shared inactivity timeout to this process and any active lease.

crates/storage/src/mobile_authentication.rs

@@ -481,10 +481,10 @@ impl MobileAuthentication {
                     match self.keys.decrypt(ciphertext, &mut provider) {
                         Ok(plaintext) => {
                             drop(plaintext);
-                            if biometric_enabled {
-                                handle
-                                    .persist_passphrase(key)
-                                    .map_err(MobileAuthenticationError::authentication)?;
+                            if biometric_enabled && let Err(error) = handle.persist_passphrase(key)
+                            {
+                                let _ = self.manual_lock();
+                                return Err(MobileAuthenticationError::authentication(error));
                             }
                             self.set_active(handle, key.clone())?;
                             return self.state();
@@ -494,7 +494,10 @@ impl MobileAuthentication {
                                 .manual_lock()
                                 .map_err(MobileAuthenticationError::authentication)?;
                         }
-                        Err(error) => return Err(key_error(error)),
+                        Err(error) => {
+                            let _ = self.manual_lock();
+                            return Err(key_error(error));
+                        }
                     }
                 }
                 Err(MobileAuthenticationError::new(
@@ -504,6 +507,7 @@ impl MobileAuthentication {
                 ))
             }
             None if biometric_enabled => {
+                let mut failure = None;
                 for key in &candidates {
                     let handle = match self.session.authenticate(key) {
                         Ok(handle) => handle,
@@ -512,7 +516,10 @@ impl MobileAuthentication {
                                 AuthenticationError::Cancelled,
                             ));
                         }
-                        Err(_) => continue,
+                        Err(error) => {
+                            failure = Some(MobileAuthenticationError::authentication(error));
+                            continue;
+                        }
                     };
                     let mut provider = KeyOnlyProvider::new(handle.clone(), key);
                     if let Ok(plaintext) = self.keys.decrypt(ciphertext, &mut provider) {
@@ -523,9 +530,9 @@ impl MobileAuthentication {
                     let _ = self.session.delete_key_passphrase(key);
                     let _ = self.session.manual_lock();
                 }
-                Err(MobileAuthenticationError::passphrase_required(
+                Err(failure.unwrap_or_else(|| MobileAuthenticationError::passphrase_required(
                     "Biometric unlock could not restore this key. Enter its GPG passphrase to recover.",
-                ))
+                )))
             }
             None => Err(MobileAuthenticationError::passphrase_required(
                 "Enter the GPG key passphrase to continue.",
@@ -533,6 +540,103 @@ impl MobileAuthentication {
         }
     }
 
+    /// Explicit enrollment also works before the store contains a password entry.
+    pub fn enroll_biometric_unlock(
+        &self,
+        passphrase: SecretBytes,
+    ) -> Result<MobileAuthenticationState, MobileAuthenticationError> {
+        self.ensure_repository_idle()?;
+        self.keys
+            .validate_secret_passphrase(self.config.default_key().as_str(), Some(&passphrase))
+            .map_err(|error| match error {
+                CryptoError::InvalidKeyPassphrase => MobileAuthenticationError::new(
+                    MobileAuthenticationErrorKind::InvalidPassphrase,
+                    "Incorrect Passphrase",
+                    "The GPG key could not be unlocked.",
+                ),
+                error => key_error(error),
+            })?;
+        let fingerprint = self
+            .keys
+            .resolve(self.config.default_key().as_str())
+            .map_err(key_error)?;
+        let key = self
+            .keys
+            .infos()
+            .find(|key| key.fingerprint() == fingerprint.fingerprint())
+            .ok_or_else(|| key_error(CryptoError::MissingSecretKey))?;
+        let handle = self
+            .session
+            .authenticate_with_passphrase(&key, passphrase)
+            .map_err(MobileAuthenticationError::authentication)?;
+        if let Err(error) = self.persist_biometric_unlock(&handle, &key) {
+            let _ = self.manual_lock();
+            return Err(error);
+        }
+        self.set_active(handle, key)?;
+        self.state()
+    }
+
+    /// Restore the configured key's lease for an explicit protected-access request.
+    pub fn restore_biometric_lease(
+        &self,
+    ) -> Result<MobileAuthenticationState, MobileAuthenticationError> {
+        self.ensure_repository_idle()?;
+        let state = self.state()?;
+        if state.unlocked() {
+            return Ok(state);
+        }
+        if !state.biometric_unlock_enabled() {
+            return Err(MobileAuthenticationError::passphrase_required(
+                "Enter the GPG key passphrase to continue.",
+            ));
+        }
+        let fingerprint = self
+            .keys
+            .resolve(self.config.default_key().as_str())
+            .map_err(key_error)?;
+        let key = self
+            .keys
+            .infos()
+            .find(|key| key.fingerprint() == fingerprint.fingerprint())
+            .ok_or_else(|| key_error(CryptoError::MissingSecretKey))?;
+        let mut handle = self
+            .session
+            .authenticate(&key)
+            .map_err(MobileAuthenticationError::authentication)?;
+        let passphrase = handle.secret_for(&key).map_err(|_| locked_error())?;
+        if self
+            .keys
+            .validate_secret_passphrase(key.fingerprint().as_str(), Some(&passphrase))
+            .is_err()
+        {
+            let _ = self.session.delete_key_passphrase(&key);
+            let _ = self.manual_lock();
+            return Err(MobileAuthenticationError::passphrase_required(
+                "The protected passphrase is unusable. Enter its GPG passphrase to recover.",
+            ));
+        }
+        self.set_active(handle, key)?;
+        self.state()
+    }
+
+    fn persist_biometric_unlock(
+        &self,
+        handle: &MobileAuthenticationHandle,
+        key: &KeyInfo,
+    ) -> Result<(), MobileAuthenticationError> {
+        handle
+            .persist_passphrase(key)
+            .map_err(MobileAuthenticationError::authentication)?;
+        if let Err(error) = self.config.update_biometric_unlock(true) {
+            let _ = self.delete_all_key_passphrases();
+            let _ = self.manual_lock();
+            return Err(config_error(error));
+        }
+        self.status()?.biometric_unlock_enabled = true;
+        Ok(())
+    }
+
     pub fn set_biometric_unlock(
         &self,
         enabled: bool,
@@ -548,17 +652,10 @@ impl MobileAuthentication {
                     "Unlock a password entry before enabling biometric unlock.",
                 )
             })?;
-            active
-                .handle
-                .persist_passphrase(&active.key)
-                .map_err(MobileAuthenticationError::authentication)?;
+            let handle = active.handle.clone();
+            let key = active.key.clone();
             drop(status);
-            if let Err(error) = self.config.update_biometric_unlock(true) {
-                let _ = self.delete_all_key_passphrases();
-                let _ = self.manual_lock();
-                return Err(config_error(error));
-            }
-            self.status()?.biometric_unlock_enabled = true;
+            self.persist_biometric_unlock(&handle, &key)?;
         } else {
             self.delete_all_key_passphrases()?;
             self.config
@@ -1961,6 +2058,40 @@ mod tests {
         watch_preference,
     };
 
+    #[test]
+    fn explicit_biometric_enrollment_and_restore_work_without_a_password_entry() {
+        use crate::authentication::SystemAuthenticationClock;
+        use std::sync::Arc;
+        let (_root, private, backend) = crate::mobile_onboarding::android::tests::home_fixture();
+        let authentication = private
+            .authentication(backend, Arc::new(SystemAuthenticationClock::default()))
+            .unwrap();
+        assert!(
+            crate::mobile_passwords::navigation::navigate_repository(
+                &authentication.repository,
+                "",
+                None,
+                None,
+                false
+            )
+            .unwrap()
+            .rows
+            .is_empty()
+        );
+        assert!(
+            authentication
+                .enroll_biometric_unlock(crate::repository::SecretBytes::new(
+                    b"fixture-alice-passphrase".to_vec()
+                ))
+                .unwrap()
+                .biometric_unlock_enabled()
+        );
+        authentication.manual_lock().unwrap();
+        assert!(authentication.restore_biometric_lease().unwrap().unlocked());
+        authentication.set_biometric_unlock(false).unwrap();
+        assert!(authentication.restore_biometric_lease().is_err());
+    }
+
     #[test]
     fn repository_actions_protect_editors_and_serialize_mutations() {
         assert_eq!(

crates/storage/src/secret_store.rs

@@ -517,6 +517,11 @@ impl<B: SecretStoreBackend> SecretStore<B> {
         self.backend.lock()
     }
 
+    /// Interrupt a platform prompt without waiting for the retrieval's state lock.
+    pub(crate) fn cancel_pending(&self) -> Result<(), SecretStoreError> {
+        self.backend.lock()
+    }
+
     pub fn create(
         &self,
         reference: &SecretReference,

crates/storage/tests/authentication_leases.rs

@@ -98,6 +98,7 @@ fn mobile_context_uses_injected_os_backend_clock_and_lifecycle_without_global_co
 struct BackendState {
     values: BTreeMap<SecretLocator, SecretBytes>,
     fault: Option<SecretStoreError>,
+    protected_fault: Option<SecretStoreError>,
     retrieves: usize,
     locks: usize,
     unlocks: usize,
@@ -112,6 +113,10 @@ impl MemoryBackend {
         self.0.lock().expect("test mutex").fault = Some(error);
     }
 
+    fn fail_protected(&self, error: SecretStoreError) {
+        self.0.lock().unwrap().protected_fault = Some(error);
+    }
+
     fn retrieves(&self) -> usize {
         self.0.lock().expect("test mutex").retrieves
     }
@@ -145,6 +150,11 @@ impl SecretStoreBackend for MemoryBackend {
     ) -> Result<(), SecretStoreError> {
         let mut state = self.0.lock().map_err(|_| SecretStoreError::Unavailable)?;
         Self::take_fault(&mut state)?;
+        if matches!(locator, SecretLocator::OpenPgpPassphrase { .. })
+            && let Some(error) = state.protected_fault.take()
+        {
+            return Err(error);
+        }
         state.last_protection = Some(protection);
         if state.values.contains_key(locator) {
             return Err(SecretStoreError::AlreadyExists);
@@ -179,6 +189,11 @@ impl SecretStoreBackend for MemoryBackend {
     ) -> Result<(), SecretStoreError> {
         let mut state = self.0.lock().map_err(|_| SecretStoreError::Unavailable)?;
         Self::take_fault(&mut state)?;
+        if matches!(locator, SecretLocator::OpenPgpPassphrase { .. })
+            && let Some(error) = state.protected_fault.take()
+        {
+            return Err(error);
+        }
         state.last_protection = Some(protection);
         let existing = state
             .values
@@ -529,3 +544,283 @@ fn verified_manual_recovery_enrolls_current_biometry_and_reestablishes_the_lease
     ));
     Ok(())
 }
+
+#[test]
+fn mobile_enrollment_proves_the_key_commits_only_after_protection_and_recovers() -> TestResult {
+    use ironstorage::{
+        config::Config,
+        mobile_authentication::{MobileAuthentication, MobileAuthenticationErrorKind},
+    };
+    let fixture = FixtureSet::load()?;
+    let vault = fixture.materialize_store("basic")?;
+    let root = tempfile::tempdir()?;
+    let source = root.path().join("config.toml");
+    std::fs::write(
+        &source,
+        format!(
+            "vault = {:?}\nkey_material = {:?}\ndefault_key = {:?}\n",
+            vault.path().to_str().unwrap(),
+            fixture.path("keys").to_str().unwrap(),
+            fixture.key("alice")?.primary_fingerprint
+        ),
+    )?;
+    let backend = MemoryBackend::default();
+    let clock = ManualClock::default();
+    let make = || -> TestResult<MobileAuthentication> {
+        Ok(MobileAuthentication::with_platform(
+            Config::load(Some(&source))?,
+            Arc::new(backend.clone()),
+            Arc::new(clock.clone()),
+        )?)
+    };
+    let authentication = make()?;
+    let password =
+        || SecretBytes::new(fixture.key("alice").unwrap().passphrase.as_bytes().to_vec());
+    assert_eq!(
+        authentication
+            .enroll_biometric_unlock(SecretBytes::new(b"incorrect".to_vec()))
+            .unwrap_err()
+            .kind(),
+        MobileAuthenticationErrorKind::InvalidPassphrase
+    );
+    assert!(backend.0.lock().unwrap().values.is_empty());
+    for (fault, kind) in [
+        (
+            SecretStoreError::Cancelled,
+            MobileAuthenticationErrorKind::Cancelled,
+        ),
+        (
+            SecretStoreError::UnsupportedProtection,
+            MobileAuthenticationErrorKind::BiometryUnavailable,
+        ),
+    ] {
+        backend.fail_protected(fault);
+        assert_eq!(
+            authentication
+                .enroll_biometric_unlock(password())
+                .unwrap_err()
+                .kind(),
+            kind
+        );
+        assert!(!authentication.state()?.unlocked());
+        assert!(!Config::load(Some(&source))?.biometric_unlock_enabled());
+        assert!(backend.0.lock().unwrap().values.is_empty());
+    }
+    let state = authentication.enroll_biometric_unlock(password())?;
+    assert!(state.unlocked() && state.biometric_unlock_enabled());
+    assert_eq!(
+        backend.last_protection(),
+        Some(SecretProtection::BiometryCurrentSet)
+    );
+    authentication.manual_lock()?;
+    assert!(
+        authentication
+            .unlock_entry("email/personal", None)?
+            .unlocked()
+    );
+    let reads = backend.retrieves();
+    authentication.unlock_entry("email/personal", None)?;
+    assert_eq!(
+        reads,
+        backend.retrieves(),
+        "an active shared lease needs no second prompt"
+    );
+    authentication.manual_lock()?;
+    backend.fail_protected(SecretStoreError::Cancelled);
+    assert_eq!(
+        authentication
+            .unlock_entry("email/personal", Some(password()))
+            .unwrap_err()
+            .kind(),
+        MobileAuthenticationErrorKind::Cancelled
+    );
+    let cancelled = authentication.state()?;
+    assert!(!cancelled.unlocked());
+    assert_eq!(cancelled.remaining_seconds(), 0);
+    for (fault, kind) in [
+        (
+            SecretStoreError::Lockout,
+            MobileAuthenticationErrorKind::BiometryUnavailable,
+        ),
+        (
+            SecretStoreError::Denied,
+            MobileAuthenticationErrorKind::BiometryUnavailable,
+        ),
+        (
+            SecretStoreError::Cancelled,
+            MobileAuthenticationErrorKind::Cancelled,
+        ),
+        (
+            SecretStoreError::Invalidated,
+            MobileAuthenticationErrorKind::PassphraseRequired,
+        ),
+        (
+            SecretStoreError::DeviceKeyMissing,
+            MobileAuthenticationErrorKind::PassphraseRequired,
+        ),
+    ] {
+        backend.fail_next(fault);
+        assert_eq!(
+            authentication
+                .unlock_entry("email/personal", None)
+                .unwrap_err()
+                .kind(),
+            kind
+        );
+        assert!(!authentication.state()?.unlocked());
+    }
+    backend.invalidate_enrollment();
+    assert_eq!(
+        authentication
+            .unlock_entry("email/personal", None)
+            .unwrap_err()
+            .kind(),
+        MobileAuthenticationErrorKind::PassphraseRequired
+    );
+    assert!(
+        authentication
+            .enroll_biometric_unlock(password())?
+            .unlocked()
+    );
+    authentication.manual_lock()?;
+    drop(authentication);
+    let recreated = make()?;
+    assert!(
+        !recreated.state()?.unlocked(),
+        "process recreation cannot restore a lease"
+    );
+    assert!(recreated.unlock_entry("email/personal", None)?.unlocked());
+    recreated.set_biometric_unlock(false)?;
+    assert!(!recreated.state()?.unlocked());
+    assert!(backend.0.lock().unwrap().values.is_empty());
+    assert!(!Config::load(Some(&source))?.biometric_unlock_enabled());
+    Ok(())
+}
+
+#[test]
+fn mobile_expiry_and_user_input_never_reveal_old_editor_handles() -> TestResult {
+    use ironstorage::{config::Config, mobile_authentication::MobileAuthentication};
+    let fixture = FixtureSet::load()?;
+    let vault = fixture.materialize_store("basic")?;
+    let root = tempfile::tempdir()?;
+    let source = root.path().join("config.toml");
+    std::fs::write(
+        &source,
+        format!(
+            "vault = {:?}\nkey_material = {:?}\ndefault_key = {:?}\n",
+            vault.path().to_str().unwrap(),
+            fixture.path("keys").to_str().unwrap(),
+            fixture.key("alice")?.primary_fingerprint
+        ),
+    )?;
+    let backend = MemoryBackend::default();
+    let clock = ManualClock::default();
+    let authentication = MobileAuthentication::with_platform(
+        Config::load(Some(&source))?,
+        Arc::new(backend),
+        Arc::new(clock.clone()),
+    )?;
+    authentication.set_authentication_timeout(2)?;
+    authentication.unlock_entry(
+        "email/personal",
+        Some(SecretBytes::new(
+            fixture.key("alice")?.passphrase.as_bytes().to_vec(),
+        )),
+    )?;
+    let editor = authentication.begin_entry_editor("email/personal")?;
+    clock.advance(Duration::from_secs(1));
+    assert_eq!(authentication.state()?.remaining_seconds(), 1);
+    authentication.touch_user_activity()?;
+    assert_eq!(authentication.state()?.remaining_seconds(), 2);
+    clock.advance(Duration::from_secs(2));
+    assert!(!authentication.state()?.unlocked());
+    assert!(authentication.entry_editor(editor.id()).is_err());
+    assert!(authentication.entry_page("email/personal", 0).is_err());
+    assert!(authentication.touch_user_activity().is_err());
+    Ok(())
+}
+
+#[test]
+fn locking_interrupts_an_os_prompt_before_waiting_for_the_lease_mutex() -> TestResult {
+    struct PromptBackend {
+        inner: MemoryBackend,
+        started: std::sync::mpsc::Sender<()>,
+        cancelled: (Mutex<bool>, std::sync::Condvar),
+    }
+    impl SecretStoreBackend for PromptBackend {
+        fn create(
+            &self,
+            locator: &SecretLocator,
+            protection: SecretProtection,
+            value: &[u8],
+        ) -> Result<(), SecretStoreError> {
+            self.inner.create(locator, protection, value)
+        }
+        fn replace(
+            &self,
+            locator: &SecretLocator,
+            protection: SecretProtection,
+            value: &[u8],
+        ) -> Result<(), SecretStoreError> {
+            self.inner.replace(locator, protection, value)
+        }
+        fn delete(
+            &self,
+            locator: &SecretLocator,
+            protection: SecretProtection,
+        ) -> Result<(), SecretStoreError> {
+            self.inner.delete(locator, protection)
+        }
+        fn retrieve(
+            &self,
+            _: &SecretLocator,
+            _: SecretProtection,
+        ) -> Result<SecretBytes, SecretStoreError> {
+            self.started.send(()).unwrap();
+            let cancelled = self.cancelled.0.lock().unwrap();
+            let (cancelled, wait) = self
+                .cancelled
+                .1
+                .wait_timeout_while(cancelled, Duration::from_secs(3), |cancelled| !*cancelled)
+                .unwrap();
+            assert!(
+                !wait.timed_out() && *cancelled,
+                "lock must interrupt the OS prompt"
+            );
+            Err(SecretStoreError::Cancelled)
+        }
+        fn lock(&self) -> Result<(), SecretStoreError> {
+            *self.cancelled.0.lock().unwrap() = true;
+            self.cancelled.1.notify_all();
+            self.inner.lock()
+        }
+        fn unlock(&self) -> Result<(), SecretStoreError> {
+            self.inner.unlock()
+        }
+    }
+    let fixture = FixtureSet::load()?;
+    let keys = KeyStore::load(fixture.path("keys"))?;
+    let alice = fixture_key(&fixture, &keys, "alice")?;
+    let (started, ready) = std::sync::mpsc::channel();
+    let backend = Arc::new(PromptBackend {
+        inner: MemoryBackend::default(),
+        started,
+        cancelled: (Mutex::new(false), std::sync::Condvar::new()),
+    });
+    let session = AuthenticationSession::with_clock(
+        backend,
+        SecretProtectionPolicy::current_biometry_for_openpgp(),
+        AuthenticationTimeout::default(),
+        ManualClock::default(),
+    );
+    let worker_session = session.clone();
+    let worker = std::thread::spawn(move || worker_session.authenticate(&alice));
+    ready.recv_timeout(Duration::from_secs(2))?;
+    session.manual_lock()?;
+    assert!(matches!(
+        worker.join().unwrap(),
+        Err(AuthenticationError::Cancelled)
+    ));
+    assert_eq!(session.remaining_time()?, None);
+    Ok(())
+}