feat: complete session preferences and PAM fixture gates

crates/latchd-auth/tests/pam_fixture.rs

@@ -0,0 +1,58 @@
+use std::env;
+
+use latchd_auth::AuthService;
+use latchd_core::error::Error;
+
+fn fixture_service() -> String {
+    env::var("LATCHD_PAM_FIXTURE_SERVICE")
+        .expect("LATCHD_PAM_FIXTURE_SERVICE must point at the disposable PAM fixture")
+}
+
+fn assert_sanitized_pam_failure(result: Result<(), Error>, secret: &str) {
+    let error = result.expect_err("the fault-injection PAM fixture must reject the operation");
+    match error {
+        Error::Pam {
+            status, message, ..
+        } => {
+            assert_ne!(status, 0);
+            assert!(!message.contains(secret));
+        }
+        _ => panic!("fault-injection fixture returned a non-PAM error"),
+    }
+}
+
+#[test]
+#[ignore = "requires the disposable PAM fixture installed by the Docker/VM harness"]
+fn authentication_fault_is_rejected_without_secret_leakage() {
+    let service = AuthService::new().expect("PAM worker should start");
+    let secret = "fixture-auth-secret";
+    let result = service.authenticate("root".into(), secret.as_bytes().to_vec(), fixture_service());
+    let error = match result {
+        Ok(_) => panic!("pam_deny fixture must reject authentication"),
+        Err(error) => error,
+    };
+    match error {
+        Error::Pam {
+            status, message, ..
+        } => {
+            assert_ne!(status, 0);
+            assert!(!message.contains(secret));
+        }
+        _ => panic!("fault-injection fixture returned a non-PAM error"),
+    }
+}
+
+#[test]
+#[ignore = "requires the disposable PAM fixture installed by the Docker/VM harness"]
+fn password_change_fault_is_rejected_without_secret_leakage() {
+    let service = AuthService::new().expect("PAM worker should start");
+    assert_sanitized_pam_failure(
+        service.change_password(
+            "root".into(),
+            b"fixture-old-secret".to_vec(),
+            b"fixture-new-secret".to_vec(),
+            fixture_service(),
+        ),
+        "fixture-new-secret",
+    );
+}