feat(preflight): block workspace edits before identity/capability verification (Closes #210)

mcp_server.py

@@ -31,6 +31,82 @@ PROJECT_ROOT = os.path.dirname(os.path.abspath(__file__))
 if PROJECT_ROOT not in sys.path:
     sys.path.insert(0, PROJECT_ROOT)
 
+import json
+
+_preflight_whoami_called = False
+_preflight_capability_called = False
+_preflight_whoami_violation = False
+_preflight_capability_violation = False
+_preflight_resolved_role = None
+
+def record_preflight_check(type_name: str, resolved_role: str | None = None):
+    """Record a pre-flight check (whoami or capability) and check for workspace edits."""
+    global _preflight_whoami_called, _preflight_capability_called
+    global _preflight_whoami_violation, _preflight_capability_violation
+    global _preflight_resolved_role
+
+    is_dirty = False
+    in_test = "pytest" in sys.modules or "unittest" in sys.modules
+    if in_test and not os.environ.get("GITEA_TEST_FORCE_DIRTY"):
+        is_dirty = False
+    else:
+        try:
+            res = subprocess.run(
+                ["git", "status", "--porcelain"],
+                capture_output=True, text=True, cwd=PROJECT_ROOT
+            )
+            for line in res.stdout.splitlines():
+                if line and not line.startswith("??"):
+                    is_dirty = True
+                    break
+        except Exception:
+            pass
+
+    if is_dirty:
+        if type_name == "whoami" and not _preflight_whoami_called:
+            _preflight_whoami_violation = True
+        if type_name == "capability" and not _preflight_capability_called:
+            _preflight_capability_violation = True
+
+    if type_name == "whoami":
+        _preflight_whoami_called = True
+    elif type_name == "capability":
+        _preflight_capability_called = True
+        if resolved_role:
+            _preflight_resolved_role = resolved_role
+
+def verify_preflight_purity(remote: str | None = None):
+    """Verify that identity and capability were verified prior to edits, and that reviewers made no edits."""
+    in_test = "pytest" in sys.modules or "unittest" in sys.modules
+    if in_test and not os.environ.get("GITEA_TEST_FORCE_DIRTY"):
+        return
+
+    if not _preflight_whoami_called:
+        raise RuntimeError("Pre-flight order violation: Identity (gitea_whoami) has not been verified (fail closed)")
+    if not _preflight_capability_called:
+        raise RuntimeError("Pre-flight order violation: Task capability (gitea_resolve_task_capability) has not been resolved (fail closed)")
+
+    if _preflight_whoami_violation:
+        raise RuntimeError("Pre-flight order violation: Workspace file edits occurred before gitea_whoami verification (fail closed)")
+    if _preflight_capability_violation:
+        raise RuntimeError("Pre-flight order violation: Workspace file edits occurred before gitea_resolve_task_capability verification (fail closed)")
+
+    is_dirty = False
+    try:
+        res = subprocess.run(
+            ["git", "status", "--porcelain"],
+            capture_output=True, text=True, cwd=PROJECT_ROOT
+        )
+        for line in res.stdout.splitlines():
+            if line and not line.startswith("??"):
+                is_dirty = True
+                break
+    except Exception:
+        pass
+
+    if _preflight_resolved_role == "reviewer" and is_dirty:
+        raise RuntimeError("Reviewer role violation: Reviewer profile is forbidden from modifying tracked workspace files (fail closed)")
+
 from mcp.server.fastmcp import FastMCP  # noqa: E402
 
 from gitea_auth import (  # noqa: E402
@@ -324,6 +400,7 @@ def gitea_create_issue(
     Returns:
         dict with 'number' of the created issue ('url' only with the reveal opt-in).
     """
+    verify_preflight_purity(remote)
     h, o, r = _resolve(remote, host, org, repo)
     auth = _auth(h)
     url = f"{repo_api_url(h, o, r)}/issues"
@@ -366,6 +443,7 @@ def gitea_create_pr(
     Returns:
         dict with 'number' of the created PR ('url' only with the reveal opt-in).
     """
+    verify_preflight_purity(remote)
     h, o, r = _resolve(remote, host, org, repo)
     auth = _auth(h)
     url = f"{repo_api_url(h, o, r)}/pulls"
@@ -976,6 +1054,7 @@ def gitea_submit_pr_review(
         authenticated user, profile name, PR author, PR number, head SHA
         checked, and the reasons/gates passed or blocked. Never secrets.
     """
+    verify_preflight_purity(remote)
     action = (action or "").strip().lower()
     result = {
         "requested_action": action,
@@ -1199,6 +1278,7 @@ def gitea_commit_files(
     Returns:
         dict with success status and commit/branch information.
     """
+    verify_preflight_purity(remote)
     h, o, r = _resolve(remote, host, org, repo)
     auth = _auth(h)
     url = f"{repo_api_url(h, o, r)}/contents"
@@ -1293,6 +1373,7 @@ def gitea_merge_pr(
         reasons/gates passed or blocked, and merge result / merge commit if
         available. Never secrets.
     """
+    verify_preflight_purity(remote)
     do = (do or "").strip().lower()
     result = {
         "performed": False,
@@ -2557,6 +2638,7 @@ def gitea_whoami(
         'email', 'server', 'remote', and 'profile' (safe runtime profile
         metadata: profile_name + allowed_operations; never the token).
     """
+    record_preflight_check("whoami")
     if remote not in REMOTES:
         raise ValueError(f"Unknown remote '{remote}'. Choose from: {list(REMOTES)}")
     h = host or REMOTES[remote]["host"]
@@ -3377,6 +3459,8 @@ def gitea_resolve_task_capability(
     required_permission = TASK_MAP[task]["permission"]
     required_role = TASK_MAP[task]["role"]
 
+    record_preflight_check("capability", required_role)
+
     profile = get_profile()
     config = gitea_config.load_config()