fix(auth): prevent repository .env files from injecting workspace bindings (Closes #704)

gitea_auth.py

@@ -22,8 +22,62 @@ import gitea_config
 
 PROJECT_ROOT = os.path.dirname(os.path.abspath(__file__))
 
-# Load standard .env if present
+# Reserved runtime-control / workspace-binding environment variables (#704).
-load_dotenv(os.path.join(PROJECT_ROOT, ".env"))
+# Repository .env files MUST NOT populate or override any of these keys.
+RESERVED_WORKTREE_ENV_KEYS: frozenset[str] = frozenset({
+    "GITEA_ACTIVE_WORKTREE",
+    "GITEA_AUTHOR_WORKTREE",
+    "GITEA_REVIEWER_WORKTREE",
+    "GITEA_MERGER_WORKTREE",
+    "GITEA_RECONCILER_WORKTREE",
+})
+
+
+def is_reserved_worktree_env_key(key: str | None) -> bool:
+    """Return True if *key* is a reserved runtime workspace binding variable (#704)."""
+    if not key:
+        return False
+    k = str(key).upper().strip()
+    return k in RESERVED_WORKTREE_ENV_KEYS or (k.startswith("GITEA_") and k.endswith("_WORKTREE"))
+
+
+def load_env_file_sanitized(
+    env_path: str,
+    *,
+    target_env: dict | os._Environ | None = None,
+) -> list[str]:
+    """Load a .env file without populating or overriding reserved workspace keys (#704).
+
+    Pre-existing process environment values retain their precedence. Reserved
+    runtime-control keys found in repository files are ignored (without logging
+    their values). Returns a list of sanitized rejection reasons.
+    """
+    if target_env is None:
+        target_env = os.environ
+    if not os.path.exists(env_path) or os.path.isdir(env_path):
+        return []
+
+    rejection_reasons: list[str] = []
+    try:
+        file_vals = dotenv_values(env_path)
+        for key, val in file_vals.items():
+            if not key or val is None:
+                continue
+            if is_reserved_worktree_env_key(key):
+                filename = os.path.basename(env_path)
+                rejection_reasons.append(
+                    f"Ignored reserved runtime workspace key '{key}' from repository {filename}"
+                )
+                continue
+            if key not in target_env:
+                target_env[key] = val
+    except Exception:
+        pass
+    return rejection_reasons
+
+
+# Load standard .env if present (sanitized to prevent repo workspace binding contamination #704)
+load_env_file_sanitized(os.path.join(PROJECT_ROOT, ".env"))
 
 # Dictionary to store configurations parsed dynamically from .env.* files
 DYNAMIC_CONFIGS = {}
@@ -37,9 +91,13 @@ for env_path in glob.glob(os.path.join(PROJECT_ROOT, ".env*")):
         continue
     try:
         config_vals = dotenv_values(env_path)
-        site = config_vals.get("GITEA_SITE") or config_vals.get("GITEA_HOST")
+        # Filter out reserved workspace keys from dynamic configs (#704)
+        sanitized_config = {
+            k: v for k, v in config_vals.items() if not is_reserved_worktree_env_key(k)
+        }
+        site = sanitized_config.get("GITEA_SITE") or sanitized_config.get("GITEA_HOST")
         if site:
-            DYNAMIC_CONFIGS[site.lower().strip()] = config_vals
+            DYNAMIC_CONFIGS[site.lower().strip()] = sanitized_config
     except Exception:
         pass
 

tests/test_issue_704_prevent_env_workspace_bindings.py

@@ -0,0 +1,166 @@
+"""Tests for Issue #704: Preventing repository .env files from injecting workspace bindings.
+
+Acceptance Criteria (#704):
+1. Repository .env loading cannot populate or override GITEA_ACTIVE_WORKTREE or any role-specific GITEA_*_WORKTREE runtime-binding variable.
+2. Runtime workspace bindings are accepted only from sanctioned managed-launch/session mechanisms.
+3. Pre-existing sanctioned process environment values retain their intended precedence.
+4. Importing gitea_auth or related modules does not mutate workspace-binding state from repository files.
+5. Reserved runtime-control keys found in .env are ignored or rejected with a sanitized actionable reason; their values are never logged.
+6. The protection applies consistently to author, reviewer, merger, and reconciler namespaces.
+7. Comprehensive test coverage for stale worktree, missing worktree, task-specific, role-specific, launcher binding, repeated imports, namespace isolation, precedence, and absence of secret leakage.
+8. Dirty-state and workspace-preflight gates cannot be bypassed by an injected missing-path binding.
+9. No environment, dotenv, offline-import, or caller-controlled path can forge native transport or mutation provenance.
+10. Cross-linked with #702, PR #703, #510.
+11. Required immediate follow-up to Issue #702 / PR #703.
+"""
+
+from __future__ import annotations
+
+import os
+import sys
+import tempfile
+import importlib
+import unittest
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+import gitea_auth
+from gitea_auth import is_reserved_worktree_env_key, load_env_file_sanitized
+
+
+class TestIssue704PreventEnvWorkspaceBindings(unittest.TestCase):
+    """Test suite verifying .env workspace-binding injection prevention (#704)."""
+
+    def setUp(self):
+        self.tmpdir = tempfile.TemporaryDirectory()
+        self.addCleanup(self.tmpdir.cleanup)
+        self.env_dir = Path(self.tmpdir.name)
+
+    def test_is_reserved_worktree_env_key(self):
+        """Verify key classification for all role namespaces (#704 AC6)."""
+        reserved_keys = [
+            "GITEA_ACTIVE_WORKTREE",
+            "GITEA_AUTHOR_WORKTREE",
+            "GITEA_REVIEWER_WORKTREE",
+            "GITEA_MERGER_WORKTREE",
+            "GITEA_RECONCILER_WORKTREE",
+            "gitea_active_worktree",
+            "GITEA_CUSTOM_ROLE_WORKTREE",
+        ]
+        for key in reserved_keys:
+            self.assertTrue(
+                is_reserved_worktree_env_key(key),
+                f"Expected {key} to be recognized as a reserved worktree key",
+            )
+
+        unreserved_keys = [
+            "GITEA_USER",
+            "GITEA_PASS",
+            "GITEA_TOKEN",
+            "GITEA_HOST",
+            "PATH",
+        ]
+        for key in unreserved_keys:
+            self.assertFalse(
+                is_reserved_worktree_env_key(key),
+                f"Expected {key} to NOT be recognized as a reserved worktree key",
+            )
+
+    def test_load_env_file_sanitized_ignores_reserved_keys(self):
+        """Verify .env loading ignores GITEA_ACTIVE_WORKTREE and role-specific keys (#704 AC1)."""
+        env_file = self.env_dir / ".env"
+        stale_path = "/tmp/stale-worktree-path-1234"
+        env_file.write_text(
+            f"GITEA_USER=testuser\n"
+            f"GITEA_ACTIVE_WORKTREE={stale_path}\n"
+            f"GITEA_AUTHOR_WORKTREE={stale_path}\n"
+            f"GITEA_REVIEWER_WORKTREE={stale_path}\n"
+            f"GITEA_MERGER_WORKTREE={stale_path}\n"
+            f"GITEA_RECONCILER_WORKTREE={stale_path}\n"
+        )
+
+        test_env = {}
+        reasons = load_env_file_sanitized(str(env_file), target_env=test_env)
+
+        # Unreserved key loaded
+        self.assertEqual(test_env.get("GITEA_USER"), "testuser")
+
+        # Reserved keys ignored
+        self.assertNotIn("GITEA_ACTIVE_WORKTREE", test_env)
+        self.assertNotIn("GITEA_AUTHOR_WORKTREE", test_env)
+        self.assertNotIn("GITEA_REVIEWER_WORKTREE", test_env)
+        self.assertNotIn("GITEA_MERGER_WORKTREE", test_env)
+        self.assertNotIn("GITEA_RECONCILER_WORKTREE", test_env)
+
+        # Rejection reasons populated without leaking the secret value (#704 AC5)
+        self.assertTrue(len(reasons) >= 5)
+        for r in reasons:
+            self.assertNotIn(stale_path, r, "Secret/path value must not leak into rejection reason")
+
+    def test_preexisting_sanctioned_launcher_env_retained(self):
+        """Sanctioned launcher values in process env are retained (#704 AC2, AC3)."""
+        sanctioned_path = "/tmp/sanctioned-launcher-worktree"
+        test_env = {"GITEA_ACTIVE_WORKTREE": sanctioned_path}
+
+        env_file = self.env_dir / ".env"
+        env_file.write_text("GITEA_ACTIVE_WORKTREE=/tmp/injected-repo-worktree\n")
+
+        load_env_file_sanitized(str(env_file), target_env=test_env)
+
+        # Pre-existing value retained, not overwritten by .env
+        self.assertEqual(test_env.get("GITEA_ACTIVE_WORKTREE"), sanctioned_path)
+
+    def test_stale_or_missing_worktree_in_env_ignored(self):
+        """Stale or non-existent worktree path in .env file is ignored (#704 AC7)."""
+        nonexistent_path = "/nonexistent/branches/stale-issue-999"
+        env_file = self.env_dir / ".env"
+        env_file.write_text(f"GITEA_ACTIVE_WORKTREE={nonexistent_path}\n")
+
+        test_env = {}
+        load_env_file_sanitized(str(env_file), target_env=test_env)
+
+        self.assertNotIn("GITEA_ACTIVE_WORKTREE", test_env)
+
+    def test_repeated_module_import_does_not_mutate_workspace_env(self):
+        """Repeated imports of gitea_auth leave os.environ un-contaminated (#704 AC4, AC7)."""
+        # Ensure no active worktree env exists initially
+        original_val = os.environ.pop("GITEA_ACTIVE_WORKTREE", None)
+        try:
+            importlib.reload(gitea_auth)
+            self.assertNotIn("GITEA_ACTIVE_WORKTREE", os.environ)
+
+            importlib.reload(gitea_auth)
+            self.assertNotIn("GITEA_ACTIVE_WORKTREE", os.environ)
+        finally:
+            if original_val is not None:
+                os.environ["GITEA_ACTIVE_WORKTREE"] = original_val
+
+    def test_namespace_isolation_all_roles_protected(self):
+        """Verify protection across author, reviewer, merger, reconciler (#704 AC6)."""
+        env_file = self.env_dir / ".env"
+        env_file.write_text(
+            "GITEA_AUTHOR_WORKTREE=/bad/author\n"
+            "GITEA_REVIEWER_WORKTREE=/bad/reviewer\n"
+            "GITEA_MERGER_WORKTREE=/bad/merger\n"
+            "GITEA_RECONCILER_WORKTREE=/bad/reconciler\n"
+        )
+        test_env = {}
+        load_env_file_sanitized(str(env_file), target_env=test_env)
+
+        self.assertEqual(test_env, {})
+
+    def test_absence_of_secret_leakage(self):
+        """Rejection reasons contain key names but never secret path values (#704 AC5)."""
+        sensitive_path = "/Users/secret/path/private_repo"
+        env_file = self.env_dir / ".env"
+        env_file.write_text(f"GITEA_ACTIVE_WORKTREE={sensitive_path}\n")
+
+        test_env = {}
+        reasons = load_env_file_sanitized(str(env_file), target_env=test_env)
+        for reason in reasons:
+            self.assertNotIn(sensitive_path, reason)
+
+
+if __name__ == "__main__":
+    unittest.main()