fix(windows): support constrained PowerShell sessions

crates/codex-win-engine/src/authenticode.rs

@@ -107,25 +107,39 @@ fn powershell_exe() -> PathBuf {
         .unwrap_or_else(|| PathBuf::from("powershell.exe"))
 }
 
+// PowerShell custom-object casts are rejected by ConstrainedLanguage. A plain
+// hashtable serializes to the same JSON shape while remaining usable under
+// AppLocker / WDAC-managed sessions.
 #[cfg(windows)]
-pub fn verify_openai_authenticode(path: &Path) -> Result<AuthenticodeReport, EngineError> {
-    log::info!("Authenticode verification start");
-    let script = format!(
+const AUTHENTICODE_REPORT_PROJECTION: &str = r#"
+@{
+  status = [string]$sig.Status
+  statusMessage = [string]$sig.StatusMessage
+  subject = if ($sig.SignerCertificate) { [string]$sig.SignerCertificate.Subject } else { '' }
+  issuer = if ($sig.SignerCertificate) { [string]$sig.SignerCertificate.Issuer } else { '' }
+  thumbprint = if ($sig.SignerCertificate) { [string]$sig.SignerCertificate.Thumbprint } else { '' }
+} | ConvertTo-Json -Compress
+"#;
+
+#[cfg(windows)]
+fn authenticode_script(path: &Path) -> String {
+    format!(
         r#"
 $ErrorActionPreference = 'Stop'
 $securityModule = Join-Path $env:WINDIR 'System32\WindowsPowerShell\v1.0\Modules\Microsoft.PowerShell.Security\Microsoft.PowerShell.Security.psd1'
 Import-Module $securityModule -ErrorAction Stop
 $sig = Get-AuthenticodeSignature -LiteralPath {path}
-[pscustomobject]@{{
-  status = [string]$sig.Status
-  statusMessage = [string]$sig.StatusMessage
-  subject = if ($sig.SignerCertificate) {{ [string]$sig.SignerCertificate.Subject }} else {{ '' }}
-  issuer = if ($sig.SignerCertificate) {{ [string]$sig.SignerCertificate.Issuer }} else {{ '' }}
-  thumbprint = if ($sig.SignerCertificate) {{ [string]$sig.SignerCertificate.Thumbprint }} else {{ '' }}
-}} | ConvertTo-Json -Compress
+{report_projection}
 "#,
-        path = ps_quote(&path.to_string_lossy())
-    );
+        path = ps_quote(&path.to_string_lossy()),
+        report_projection = AUTHENTICODE_REPORT_PROJECTION,
+    )
+}
+
+#[cfg(windows)]
+pub fn verify_openai_authenticode(path: &Path) -> Result<AuthenticodeReport, EngineError> {
+    log::info!("Authenticode verification start");
+    let script = authenticode_script(path);
 
     let mut command = hidden_command(powershell_exe());
     command.args(["-NoProfile", "-NonInteractive", "-Command", &script]);
@@ -219,4 +233,33 @@ mod tests {
         .unwrap();
         assert!(!report.is_valid_openai());
     }
+
+    #[cfg(windows)]
+    #[test]
+    fn authenticode_script_runs_in_constrained_language() {
+        let path = std::env::current_exe().expect("resolve current test executable");
+        let production_script = super::authenticode_script(&path);
+        let script = format!(
+            r#"$ErrorActionPreference = 'Stop'
+$ExecutionContext.SessionState.LanguageMode = 'ConstrainedLanguage'
+if ($ExecutionContext.SessionState.LanguageMode -ne 'ConstrainedLanguage') {{
+  throw 'failed to enter ConstrainedLanguage'
+}}
+{production_script}
+"#,
+            production_script = production_script,
+        );
+        let output = super::hidden_command(super::powershell_exe())
+            .args(["-NoProfile", "-NonInteractive", "-Command", &script])
+            .output()
+            .expect("run constrained-language Authenticode script");
+        assert!(
+            output.status.success(),
+            "Authenticode script failed: {}",
+            String::from_utf8_lossy(&output.stderr)
+        );
+        let report = report_from_json(String::from_utf8_lossy(&output.stdout).trim())
+            .expect("parse constrained-language Authenticode report");
+        assert!(!report.status.is_empty());
+    }
 }

crates/codex-win-engine/src/lib.rs

@@ -87,3 +87,20 @@ pub enum EngineError {
     #[error("io error: {0}")]
     Io(String),
 }
+
+#[cfg(test)]
+mod constrained_language_regressions {
+    #[test]
+    fn runtime_powershell_avoids_custom_object_casts() {
+        let forbidden = ["[pscustom", "object]"].concat();
+        for (name, source) in [
+            ("authenticode.rs", include_str!("authenticode.rs")),
+            ("sys.rs", include_str!("sys.rs")),
+        ] {
+            assert!(
+                !source.to_ascii_lowercase().contains(&forbidden),
+                "{name} contains a PowerShell custom-object cast that fails in ConstrainedLanguage"
+            );
+        }
+    }
+}

crates/codex-win-engine/src/portable.rs

@@ -282,7 +282,7 @@ fn request_codex_close_filtered(timeout_secs: u64, root: &Path) -> Result<(), En
     let script = format!(
         r#"
 $RootFilter = {root_filter}
-try {{ $RootFilter = [System.IO.Path]::GetFullPath($RootFilter).TrimEnd('\') }} catch {{}}
+try {{ $RootFilter = ([string](Convert-Path -LiteralPath $RootFilter -ErrorAction Stop)).TrimEnd('\') }} catch {{}}
 function Get-ProcessExePath($p) {{
   try {{
     $path = [string]$p.Path
@@ -303,21 +303,20 @@ function Get-ProcessExePath($p) {{
 function Test-UnderRoot($p) {{
   $path = Get-ProcessExePath $p
   if ([string]::IsNullOrWhiteSpace($path) -or [string]::IsNullOrWhiteSpace($RootFilter)) {{ return $false }}
+  $full = [string]$path
   try {{
-    $full = [System.IO.Path]::GetFullPath($path)
-    return ($full.Equals($RootFilter, [System.StringComparison]::OrdinalIgnoreCase) -or
-            $full.StartsWith($RootFilter + '\', [System.StringComparison]::OrdinalIgnoreCase))
-  }} catch {{
-    return $false
-  }}
+    $resolved = [string](Convert-Path -LiteralPath $path -ErrorAction Stop)
+    if (-not [string]::IsNullOrWhiteSpace($resolved)) {{ $full = $resolved }}
+  }} catch {{}}
+  return ($full.Equals($RootFilter, [System.StringComparison]::OrdinalIgnoreCase) -or
+          $full.StartsWith($RootFilter + '\', [System.StringComparison]::OrdinalIgnoreCase))
 }}
 function Get-TargetCodexProcess {{
   $all = Get-Process -Name Codex, ChatGPT -ErrorAction SilentlyContinue
   foreach ($p in $all) {{
     if (Test-UnderRoot $p) {{ $p }}
   }}
 }}
-$deadline = (Get-Date).AddSeconds({timeout})
 $procs = @(Get-TargetCodexProcess)
 if ($procs.Count -eq 0) {{
   'no-targets'
@@ -329,6 +328,7 @@ foreach ($p in $procs) {{
     if ($p.MainWindowHandle -ne 0) {{ [void]$p.CloseMainWindow() }}
   }} catch {{}}
 }}
+$deadline = (Get-Date).AddSeconds({timeout})
 while ((Get-Date) -lt $deadline) {{
   Start-Sleep -Milliseconds 250
   $remaining = @()