Files
Gitea-Tools/role_namespace_gate.py
T
sysadminandClaude Opus 4.8 cbce6cb2e7 Block author mutations from reviewer MCP namespace (Issue #209)
Add role_namespace_gate to fail closed when reviewer-bound sessions attempt
author mutations (create_pr always blocked; create_issue only when profile
explicitly grants gitea.issue.create). Extend mutation audit records with
mcp_namespace, task_role, and operation fields. Add handoff parity checks in
review_proofs for author role vs reviewer namespace mismatches.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
2026-07-05 21:12:33 -04:00

89 lines
3.1 KiB
Python

"""Block author mutations from reviewer-bound MCP namespaces (#209).
Every mutation must prove that the active profile role, inferred MCP
namespace, and declared task role align. Reviewer sessions cannot silently
perform author-side work (especially PR creation).
"""
from __future__ import annotations
import gitea_config
import role_session_router
def infer_mcp_namespace(profile_name: str | None) -> str:
"""Map a runtime profile name to its MCP namespace label."""
lower = (profile_name or "").strip().lower()
if "reviewer" in lower and "author" not in lower:
return "gitea-reviewer"
if "author" in lower:
return "gitea-author"
return profile_name or "gitea-default"
def derive_role_kind(allowed, forbidden=()) -> str:
"""Classify the active profile the same way as ``mcp_server._role_kind``."""
def can(op):
return gitea_config.check_operation(op, allowed, forbidden)[0]
review = can("gitea.pr.approve") or can("gitea.pr.merge")
author = can("gitea.pr.create") or can("gitea.branch.push")
if review and author:
return "mixed"
if review:
return "reviewer"
if author:
return "author"
return "limited"
def check_author_mutation_namespace(
mutation_task: str,
profile: dict,
) -> tuple[bool, list[str]]:
"""Return (allowed, reasons). Fail closed on reviewer/author mismatch."""
required_role = role_session_router.required_role_for_task(mutation_task)
if required_role != "author":
return True, []
allowed = profile.get("allowed_operations") or []
forbidden = profile.get("forbidden_operations") or []
active_role = derive_role_kind(allowed, forbidden)
profile_name = profile.get("profile_name") or ""
namespace = infer_mcp_namespace(profile_name)
if mutation_task == "create_pr":
if active_role == "reviewer" or namespace == "gitea-reviewer":
return False, [
"author mutation 'create_pr' blocked in reviewer MCP namespace "
f"({namespace}); launch gitea-author",
]
if active_role == "reviewer" or namespace == "gitea-reviewer":
if mutation_task == "create_issue":
ok, _ = gitea_config.check_operation(
"gitea.issue.create", allowed, forbidden)
if ok:
return True, []
return False, [
f"author mutation '{mutation_task}' blocked: active session is "
f"reviewer-bound ({profile_name} / {namespace})",
]
return True, []
def mutation_audit_context(mutation_task: str, profile: dict, *,
remote=None, repository=None) -> dict:
"""Structured mutation metadata for audit records (#209)."""
allowed = profile.get("allowed_operations") or []
forbidden = profile.get("forbidden_operations") or []
return {
"mcp_namespace": infer_mcp_namespace(profile.get("profile_name")),
"profile_name": profile.get("profile_name"),
"task_role": role_session_router.required_role_for_task(mutation_task),
"operation": mutation_task,
"remote": remote,
"repository": repository,
}