Files
codex/codex-rs/core/tests/suite/windows_sandbox.rs
viyatb-oai 46f30d0282 feat(sandbox): add Windows deny-read parity (#18202)
## Why

The split filesystem policy stack already supports exact and glob
`access = none` read restrictions on macOS and Linux. Windows still
needed subprocess handling for those deny-read policies without claiming
enforcement from a backend that cannot provide it.

## Key finding

The unelevated restricted-token backend cannot safely enforce deny-read
overlays. Its `WRITE_RESTRICTED` token model is authoritative for write
checks, not read denials, so this PR intentionally fails that backend
closed when deny-read overrides are present instead of claiming
unsupported enforcement.

## What changed

This PR adds the Windows deny-read enforcement layer and makes the
backend split explicit:

- Resolves Windows deny-read filesystem policy entries into concrete ACL
targets.
- Preserves exact missing paths so they can be materialized and denied
before an enforceable sandboxed process starts.
- Snapshot-expands existing glob matches into ACL targets for Windows
subprocess enforcement.
- Honors `glob_scan_max_depth` when expanding Windows deny-read globs.
- Plans both the configured lexical path and the canonical target for
existing paths so reparse-point aliases are covered.
- Threads deny-read overrides through the elevated/logon-user Windows
sandbox backend and unified exec.
- Applies elevated deny-read ACLs synchronously before command launch
rather than delegating them to the background read-grant helper.
- Reconciles persistent deny-read ACEs per sandbox principal so policy
changes do not leave stale deny-read ACLs behind.
- Fails closed on the unelevated restricted-token backend when deny-read
overrides are present, because its `WRITE_RESTRICTED` token model is not
authoritative for read denials.

## Landed prerequisites

These prerequisite PRs are already on `main`:

1. #15979 `feat(permissions): add glob deny-read policy support`
2. #18096 `feat(sandbox): add glob deny-read platform enforcement`
3. #17740 `feat(config): support managed deny-read requirements`

This PR targets `main` directly and contains only the Windows deny-read
enforcement layer.

## Implementation notes

- Exact deny-read paths remain enforceable on the elevated path even
when they do not exist yet: Windows materializes the missing path before
applying the deny ACE, so the sandboxed command cannot create and read
it during the same run.
- Existing exact deny paths are preserved lexically until the ACL
planner, which then adds the canonical target as a second ACL target
when needed. That keeps both the configured alias and the resolved
object covered.
- Windows ACLs do not consume Codex glob syntax directly, so glob
deny-read entries are expanded to the concrete matches that exist before
process launch.
- Glob traversal deduplicates directory visits within each pattern walk
to avoid cycles, without collapsing distinct lexical roots that happen
to resolve to the same target.
- Persistent deny-read ACL state is keyed by sandbox principal SID, so
cleanup only removes ACEs owned by the same backend principal.
- Deny-read ACEs are fail-closed on the elevated path: setup aborts if
mandatory deny-read ACL application fails.
- Unelevated restricted-token sessions reject deny-read overrides early
instead of running with a silently unenforceable read policy.

## Verification

- `cargo test -p codex-core
windows_restricted_token_rejects_unreadable_split_carveouts`
- `just fmt`
- `just fix -p codex-core`
- `just fix -p codex-windows-sandbox`
- GitHub Actions rerun is in progress on the pushed head.

---------

Co-authored-by: Codex <noreply@openai.com>
2026-05-11 23:04:28 -07:00

244 lines
8.4 KiB
Rust

use anyhow::Context;
use codex_core::exec::ExecCapturePolicy;
use codex_core::exec::ExecParams;
use codex_core::exec::process_exec_tool_call;
use codex_core::sandboxing::SandboxPermissions;
use codex_protocol::config_types::WindowsSandboxLevel;
use codex_protocol::exec_output::ExecToolCallOutput;
use codex_protocol::models::PermissionProfile;
use codex_protocol::permissions::FileSystemAccessMode;
use codex_protocol::permissions::FileSystemPath;
use codex_protocol::permissions::FileSystemSandboxEntry;
use codex_protocol::permissions::FileSystemSandboxPolicy;
use codex_protocol::permissions::FileSystemSpecialPath;
use codex_protocol::permissions::NetworkSandboxPolicy;
use core_test_support::PathExt;
use pretty_assertions::assert_eq;
use serial_test::serial;
use std::collections::HashMap;
use std::ffi::OsString;
use std::path::Path;
use tempfile::TempDir;
struct EnvVarGuard {
key: &'static str,
original: Option<OsString>,
}
impl EnvVarGuard {
fn set(key: &'static str, value: &std::ffi::OsStr) -> Self {
let original = std::env::var_os(key);
unsafe {
std::env::set_var(key, value);
}
Self { key, original }
}
}
impl Drop for EnvVarGuard {
fn drop(&mut self) {
unsafe {
match &self.original {
Some(value) => std::env::set_var(self.key, value),
None => std::env::remove_var(self.key),
}
}
}
}
fn stage_windows_sandbox_helpers() -> anyhow::Result<()> {
let test_exe = std::env::current_exe().context("resolve current Windows test executable")?;
let test_exe_dir = test_exe
.parent()
.context("Windows test executable should have a parent directory")?;
let resources_dir = test_exe_dir.join("codex-resources");
std::fs::create_dir_all(&resources_dir)?;
for helper_name in ["codex-windows-sandbox-setup", "codex-command-runner"] {
let helper = codex_utils_cargo_bin::cargo_bin(helper_name)?;
let file_name = Path::new(helper_name).with_extension("exe");
std::fs::copy(helper, resources_dir.join(file_name))?;
}
Ok(())
}
#[tokio::test]
#[serial(codex_home)]
async fn windows_restricted_token_rejects_exact_and_glob_deny_read_policy() -> anyhow::Result<()> {
let temp_home = TempDir::new()?;
let _codex_home_guard = EnvVarGuard::set("CODEX_HOME", temp_home.path().as_os_str());
let workspace = TempDir::new()?;
let cwd = dunce::canonicalize(workspace.path())?.abs();
let secret = cwd.join("secret.env");
let future_secret = cwd.join("future.env");
let public = cwd.join("public.txt");
std::fs::write(&secret, "glob secret\n")?;
std::fs::write(&public, "public ok\n")?;
let file_system_sandbox_policy = FileSystemSandboxPolicy::restricted(vec![
FileSystemSandboxEntry {
path: FileSystemPath::Special {
value: FileSystemSpecialPath::Root,
},
access: FileSystemAccessMode::Read,
},
FileSystemSandboxEntry {
path: FileSystemPath::Special {
value: FileSystemSpecialPath::project_roots(/*subpath*/ None),
},
access: FileSystemAccessMode::Write,
},
FileSystemSandboxEntry {
path: FileSystemPath::GlobPattern {
pattern: "**/*.env".to_string(),
},
access: FileSystemAccessMode::None,
},
FileSystemSandboxEntry {
path: FileSystemPath::Path {
path: future_secret,
},
access: FileSystemAccessMode::None,
},
]);
let permission_profile = PermissionProfile::from_runtime_permissions(
&file_system_sandbox_policy,
NetworkSandboxPolicy::Restricted,
);
let err = process_exec_tool_call(
ExecParams {
command: vec![
"cmd.exe".to_string(),
"/D".to_string(),
"/C".to_string(),
"type secret.env >NUL 2>NUL & echo exact secret 1>future.env 2>NUL & type future.env 2>NUL & type public.txt & exit /B 0"
.to_string(),
],
cwd: cwd.clone(),
expiration: 10_000.into(),
capture_policy: ExecCapturePolicy::ShellTool,
env: HashMap::new(),
network: None,
sandbox_permissions: SandboxPermissions::UseDefault,
windows_sandbox_level: WindowsSandboxLevel::RestrictedToken,
windows_sandbox_private_desktop: false,
justification: None,
arg0: None,
},
&permission_profile,
&cwd,
&None,
/*use_legacy_landlock*/ false,
/*stdout_stream*/ None,
)
.await
.expect_err("restricted-token sandbox should reject deny-read restrictions");
assert_eq!(
err.to_string(),
"unsupported operation: windows unelevated restricted-token sandbox cannot enforce deny-read restrictions directly; refusing to run unsandboxed"
);
Ok(())
}
#[tokio::test]
#[serial(codex_home)]
async fn windows_elevated_enforces_exact_and_glob_deny_read_policy() -> anyhow::Result<()> {
let temp_home = TempDir::new()?;
let _codex_home_guard = EnvVarGuard::set("CODEX_HOME", temp_home.path().as_os_str());
stage_windows_sandbox_helpers()?;
let workspace = TempDir::new()?;
let cwd = dunce::canonicalize(workspace.path())?.abs();
let glob_secret = cwd.join("secret.env");
let exact_secret = cwd.join("exact-secret.txt");
let public = cwd.join("public.txt");
std::fs::write(&glob_secret, "glob secret\n")?;
std::fs::write(&exact_secret, "exact secret\n")?;
std::fs::write(&public, "public ok\n")?;
let file_system_sandbox_policy = FileSystemSandboxPolicy::restricted(vec![
FileSystemSandboxEntry {
path: FileSystemPath::Special {
value: FileSystemSpecialPath::Root,
},
access: FileSystemAccessMode::Read,
},
FileSystemSandboxEntry {
path: FileSystemPath::Special {
value: FileSystemSpecialPath::project_roots(/*subpath*/ None),
},
access: FileSystemAccessMode::Write,
},
FileSystemSandboxEntry {
path: FileSystemPath::GlobPattern {
pattern: "**/*.env".to_string(),
},
access: FileSystemAccessMode::None,
},
FileSystemSandboxEntry {
path: FileSystemPath::Path { path: exact_secret },
access: FileSystemAccessMode::None,
},
]);
let permission_profile = PermissionProfile::from_runtime_permissions(
&file_system_sandbox_policy,
NetworkSandboxPolicy::Restricted,
);
let ExecToolCallOutput {
exit_code,
stdout,
stderr,
..
} = process_exec_tool_call(
ExecParams {
command: vec![
"cmd.exe".to_string(),
"/D".to_string(),
"/C".to_string(),
"(type secret.env 1>NUL 2>NUL && echo GLOB-READ || echo GLOB-DENIED) & (type exact-secret.txt 1>NUL 2>NUL && echo EXACT-READ || echo EXACT-DENIED) & type public.txt".to_string(),
],
cwd: cwd.clone(),
expiration: 10_000.into(),
capture_policy: ExecCapturePolicy::ShellTool,
env: HashMap::new(),
network: None,
sandbox_permissions: SandboxPermissions::UseDefault,
windows_sandbox_level: WindowsSandboxLevel::Elevated,
windows_sandbox_private_desktop: false,
justification: None,
arg0: None,
},
&permission_profile,
&cwd,
&None,
/*use_legacy_landlock*/ false,
/*stdout_stream*/ None,
)
.await?;
assert_eq!(exit_code, 0, "sandboxed command should complete");
assert!(
stdout.text.contains("GLOB-DENIED"),
"glob deny-read should block the secret: {stdout:?}"
);
assert!(
!stdout.text.contains("GLOB-READ"),
"glob deny-read should not allow the secret: {stdout:?}"
);
assert!(
stdout.text.contains("EXACT-DENIED"),
"exact deny-read should block the secret: {stdout:?}"
);
assert!(
!stdout.text.contains("EXACT-READ"),
"exact deny-read should not allow the secret: {stdout:?}"
);
assert!(
stdout.text.contains("public ok"),
"allowed reads should still work: {stdout:?}"
);
assert_eq!(stderr.text, "");
Ok(())
}