Phase 3: WebSocket CSRF, SameSite=Lax, Tenant FK CASCADE

alembic/versions/0103_add_remaining_tenant_fk_cascade.py

@@ -0,0 +1,127 @@
+"""Add tenant_id FK CASCADE to remaining tables not covered by migration 0091.
+
+Tables missing from migration 0091:
+- contact_merge_history (has tenant_id from TenantMixin but no FK)
+- tenant_plugin_activation (plugin table, may not exist yet)
+- user_groups (has FK already but verify CASCADE)
+- guest_users (has FK already but verify CASCADE)
+- user_tenants (has FK already but verify CASCADE)
+
+Also adds FK to calendar_entry_links.tenant_id if not already present
+(migration 0091 includes it but the model definition lacks the FK).
+
+Revision ID: 0103
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+revision = "0103"
+down_revision = "0102"
+branch_labels = None
+depends_on = None
+
+# Tables that need tenant_id FK with CASCADE but were not in migration 0091
+TABLES_NEEDING_FK = [
+    "contact_merge_history",
+    "tenant_plugin_activation",
+]
+
+# Tables that should already have FK but we verify CASCADE is set
+TABLES_VERIFY_CASCADE = [
+    "user_groups",
+    "guest_users",
+    "user_tenants",
+]
+
+
+def _table_exists(conn, table_name: str) -> bool:
+    result = conn.execute(
+        sa.text("SELECT EXISTS (SELECT 1 FROM information_schema.tables WHERE table_name = :name)"),
+        {"name": table_name},
+    )
+    return result.scalar()
+
+
+def _fk_exists(conn, table_name: str, constraint_name: str) -> bool:
+    result = conn.execute(
+        sa.text(
+            "SELECT EXISTS (SELECT 1 FROM information_schema.table_constraints "
+            "WHERE constraint_name = :name AND constraint_type = 'FOREIGN KEY')"
+        ),
+        {"name": constraint_name},
+    )
+    return result.scalar()
+
+
+def upgrade() -> None:
+    conn = op.get_bind()
+
+    # Add FK CASCADE to tables that are missing it
+    for table_name in TABLES_NEEDING_FK:
+        if not _table_exists(conn, table_name):
+            print(f"[0103] Skipping {table_name} — table does not exist")
+            continue
+        constraint_name = f"fk_{table_name}_tenant_id"
+        if _fk_exists(conn, table_name, constraint_name):
+            print(f"[0103] Skipping {table_name} — FK already exists")
+            continue
+        # Check if tenant_id column exists
+        col_exists = conn.execute(
+            sa.text(
+                "SELECT EXISTS (SELECT 1 FROM information_schema.columns "
+                "WHERE table_name = :name AND column_name = 'tenant_id')"
+            ),
+            {"name": table_name},
+        ).scalar()
+        if not col_exists:
+            print(f"[0103] Skipping {table_name} — no tenant_id column")
+            continue
+        op.execute(
+            f"ALTER TABLE {table_name} ADD CONSTRAINT {constraint_name} "
+            f"FOREIGN KEY (tenant_id) REFERENCES tenants(id) ON DELETE CASCADE;"
+        )
+        print(f"[0103] Added FK CASCADE to {table_name}")
+
+    # Verify CASCADE on existing FKs (drop and recreate if missing CASCADE)
+    for table_name in TABLES_VERIFY_CASCADE:
+        if not _table_exists(conn, table_name):
+            continue
+        constraint_name = f"fk_{table_name}_tenant_id"
+        if not _fk_exists(conn, table_name, constraint_name):
+            # Check if any FK exists on tenant_id
+            existing_fk = conn.execute(
+                sa.text(
+                    "SELECT conname FROM pg_constraint con "
+                    "JOIN pg_class cls ON con.conrelid = cls.oid "
+                    "WHERE cls.relname = :table AND con.contype = 'f' "
+                    "AND EXISTS (SELECT 1 FROM pg_attribute att "
+                    "WHERE att.attrelid = con.conrelid AND att.attname = 'tenant_id' "
+                    "AND att.attnum = ANY(con.conkey))"
+                ),
+                {"table": table_name},
+            ).scalar_one_or_none()
+            if existing_fk:
+                # Drop existing FK and recreate with CASCADE
+                op.execute(f"ALTER TABLE {table_name} DROP CONSTRAINT {existing_fk};")
+                op.execute(
+                    f"ALTER TABLE {table_name} ADD CONSTRAINT {constraint_name} "
+                    f"FOREIGN KEY (tenant_id) REFERENCES tenants(id) ON DELETE CASCADE;"
+                )
+                print(f"[0103] Replaced FK on {table_name} with CASCADE (was: {existing_fk})")
+            else:
+                op.execute(
+                    f"ALTER TABLE {table_name} ADD CONSTRAINT {constraint_name} "
+                    f"FOREIGN KEY (tenant_id) REFERENCES tenants(id) ON DELETE CASCADE;"
+                )
+                print(f"[0103] Added FK CASCADE to {table_name}")
+
+
+def downgrade() -> None:
+    conn = op.get_bind()
+    for table_name in TABLES_NEEDING_FK + TABLES_VERIFY_CASCADE:
+        if not _table_exists(conn, table_name):
+            continue
+        constraint_name = f"fk_{table_name}_tenant_id"
+        if _fk_exists(conn, table_name, constraint_name):
+            op.execute(f"ALTER TABLE {table_name} DROP CONSTRAINT {constraint_name};")

app/config.py

@@ -39,7 +39,7 @@ class Settings(BaseSettings):
     bcrypt_rounds: int = 12
     session_cookie_name: str = "leocrm_session"
     session_cookie_secure: bool = True  # Secure by default — set to False only for local HTTP development
-    session_cookie_samesite: str = "strict"  # Strict blocks WebSocket cookies; use Lax only if WS needed
+    session_cookie_samesite: str = "lax"  # Lax allows WebSocket cookies while preventing CSRF on top-level navigations
     session_cookie_httponly: bool = True
     password_reset_expiry_hours: int = 1
 

app/core/auth.py

@@ -116,8 +116,23 @@ def verify_ws_origin(websocket) -> bool:
     # CSRF token validation: check query parameter 'csrf_token' against session
     # The frontend must send ?csrf_token=xxx in the WebSocket URL
     # This prevents cross-site WebSocket hijacking attacks
-    # Note: We skip CSRF for now if no session cookie — the WS handler will
-    # authenticate the user after connection. Origin check is the primary defense.
+    csrf_token = websocket.query_params.get("csrf_token", "")
+    if not csrf_token:
+        logger.warning("WebSocket connection rejected: missing csrf_token query parameter")
+        return False
+
+    # Validate CSRF token against session in Redis
+    session_id = websocket.cookies.get(settings.session_cookie_name)
+    if not session_id:
+        logger.warning("WebSocket connection rejected: missing session cookie")
+        return False
+
+    redis = get_redis()
+    session_data = await get_session_data(redis, session_id)
+    if not session_data or session_data.get("csrf_token") != csrf_token:
+        logger.warning("WebSocket connection rejected: invalid CSRF token")
+        return False
+
     return True