Intercept the WSL OpenBao browser launch.

OpenBao opens the login with cmd.exe /c start, so the xdg-open launcher
never ran. The attended PATH now supplies cmd.exe for that one allowlisted
URL and opens it in the empty Playwright Chromium profile.

Assistant: grok
Assistant-Session: 01a198fa-fd27-7e41-a0a2-57355c3e4efd

docs/backup-credential-recovery.md

@@ -139,13 +139,14 @@ python3 scripts/openbao-attended-exec.py -- /absolute/path/to/reviewed-silent-co
 ```
 
 The wrapper keeps Warden's `openbao-platform-admin-login --exec` envelope and
-puts the repository launcher ahead of the default `xdg-open`. The launcher
-allows only the Keycloak HTTPS host and exact local OIDC callback. It opens
-that page in a new empty profile of the headed Chromium pinned by
-coulomb-social's Playwright install. It does not open Firefox or another
-Windows default browser, and it does not record the address. The remote
-headless rapp-playwright service is a different facility and cannot complete
-this localhost callback.
+puts `scripts/operator-browser` ahead of the default command path. On this
+WSL host, OpenBao opens the page with `cmd.exe /c start`, which is the
+Windows default browser. The directory supplies a `cmd.exe` for that one
+shape. It allows only the Keycloak HTTPS host and exact local OIDC callback,
+then opens that page in a new empty profile of the headed Chromium pinned by
+coulomb-social's Playwright install. It does not record the address. The
+remote headless rapp-playwright service is a different facility and cannot
+complete this localhost callback.
 No token helper or captured Warden output may be inspected. A receipt written
 by the owner command proves handoff; session cleanup is assessed separately
 from the final Warden exit status.

scripts/operator-browser/cmd.exe

@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+"""Intercept OpenBao's WSL browser launch.
+
+hashicorp/cap opens a WSL login with `cmd.exe /c start <url>`. That reaches
+the Windows default browser. This command sits ahead of the real cmd.exe on
+the attended-login PATH and opens the allowlisted URL in Playwright Chromium.
+"""
+import os
+import runpy
+import sys
+from pathlib import Path
+
+
+REAL_CMD = "/mnt/c/Windows/System32/cmd.exe"
+launcher = runpy.run_path(str(Path(__file__).resolve().with_name("xdg-open")))
+
+
+def main():
+    kind, url = launcher["classify_cmd"](sys.argv[1:])
+    if kind == "open":
+        launcher["stamp"]("called")
+        return launcher["open_url"](url)
+    if kind == "reject":
+        launcher["stamp"]("called")
+        launcher["stamp"]("rejected")
+        return 1
+    os.execv(REAL_CMD, [REAL_CMD, *sys.argv[1:]])
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

scripts/operator-browser/xdg-open

@@ -78,6 +78,20 @@ def launch_argv(browser, profile_dir, url):
     ]
 
 
+def classify_cmd(argv):
+    """Classify OpenBao's WSL launch, `cmd.exe /c start <url>`.
+
+    hashicorp/cap replaces each & with ^& before calling the Windows
+    default browser. Other cmd.exe uses are left for the real binary.
+    """
+    if list(argv[:2]) != ["/c", "start"] or len(argv) != 3:
+        return "delegate", ""
+    url = str(argv[2]).replace("^&", "&")
+    if allowed(url):
+        return "open", url
+    return "reject", ""
+
+
 def stamp(result):
     path = Path("/home/worsch/.local/state/railiance/receipts/operator-browser-last.txt")
     try:
@@ -88,11 +102,7 @@ def stamp(result):
         return
 
 
-def main():
-    stamp("called")
-    if len(sys.argv) != 2 or not allowed(sys.argv[1]):
-        stamp("rejected")
-        return 1
+def open_url(url):
     if not os.environ.get("DISPLAY") and not os.environ.get("WAYLAND_DISPLAY"):
         stamp("no-display")
         return 1
@@ -102,7 +112,7 @@ def main():
         return 1
     profile = Path(tempfile.mkdtemp(prefix="operator-browser-"))
     os.chmod(profile, 0o700)
-    command = launch_argv(browser, str(profile), sys.argv[1])
+    command = launch_argv(browser, str(profile), url)
     try:
         subprocess.Popen(
             command,
@@ -118,5 +128,13 @@ def main():
     return 0
 
 
+def main():
+    stamp("called")
+    if len(sys.argv) != 2 or not allowed(sys.argv[1]):
+        stamp("rejected")
+        return 1
+    return open_url(sys.argv[1])
+
+
 if __name__ == "__main__":
     raise SystemExit(main())

tests/test_operator_browser.py

@@ -40,3 +40,9 @@ class BrowserBoundary(unittest.TestCase):
             binary.chmod(0o755)
             self.assertEqual(launcher['chromium_executable'](spec, root), str(binary))
             self.assertEqual(launcher['chromium_executable'](root/'missing.json', root), '')
+    def test_wsl_cmd_start_is_the_login_opener(self):
+        url='https://kc.coulomb.social/authorize?'+urlencode({'redirect_uri':'http://127.0.0.1:8250/oidc/callback','state':'test'})
+        escaped=url.replace('&','^&')
+        self.assertEqual(launcher['classify_cmd'](['/c','start',escaped]), ('open', url))
+        self.assertEqual(launcher['classify_cmd'](['/c','start','https://evil.example/']), ('reject', ''))
+        self.assertEqual(launcher['classify_cmd'](['/c','dir']), ('delegate', ''))