아바타 저장소 승격 계약을 완성

scripts/public_runtime_database_identity.py

@@ -0,0 +1,74 @@
+"""Credential-free identity for the *connected* public-runtime PostgreSQL target.
+
+The connection itself is the authority.  A configured DSN is deliberately not
+hashed because proxies, aliases, defaults, and credential changes can make a
+URL identity disagree with the server that actually owns the inventory.
+"""
+
+from __future__ import annotations
+
+import hashlib
+import json
+from typing import Any
+
+
+DATABASE_IDENTITY_QUERY = """
+SELECT
+  current_database()::text AS database_name,
+  current_user::text AS database_role,
+  COALESCE(inet_server_addr()::text, 'local') AS server_address,
+  inet_server_port() AS server_port
+"""
+
+
+def database_target_sha256(
+    *,
+    database_name: str,
+    database_role: str,
+    server_address: str,
+    server_port: int,
+) -> str:
+    """Return a lowercase SHA256 over a secret-free connected DB identity."""
+
+    if (
+        not isinstance(database_name, str)
+        or not database_name.strip()
+        or not isinstance(database_role, str)
+        or not database_role.strip()
+        or not isinstance(server_address, str)
+        or not server_address.strip()
+    ):
+        raise ValueError("database target identity is incomplete")
+    if (
+        not isinstance(server_port, int)
+        or isinstance(server_port, bool)
+        or server_port < 1
+        or server_port > 65535
+    ):
+        raise ValueError("database target port is invalid")
+    canonical = json.dumps(
+        {
+            "database": database_name,
+            "database_role": database_role,
+            "server_address": server_address,
+            "server_port": server_port,
+        },
+        ensure_ascii=True,
+        separators=(",", ":"),
+        sort_keys=True,
+    ).encode("utf-8", errors="strict")
+    return hashlib.sha256(canonical).hexdigest()
+
+
+async def connected_database_target_sha256(connection: Any) -> str:
+    """Read and hash the target identity through an already-open connection."""
+
+    target = await connection.fetchrow(DATABASE_IDENTITY_QUERY)
+    if target is None:
+        raise ValueError("database target identity is unavailable")
+    return database_target_sha256(
+        database_name=str(target["database_name"]),
+        database_role=str(target["database_role"]),
+        server_address=str(target["server_address"]),
+        server_port=int(target["server_port"]),
+    )