Phase D: Harden Shell and Backup Enforcement

[Cho-Geer]

Description

Block script payload staging (e.g., cat > /tmp/impl.ts with workspace writes) and unify shell write classification. Ensure all framework file modifications go through backup-aware tools.

Code References (§6 Phase D)

Files to Modify

• .opencode/lib/tool-scope.ts
• .opencode/lib/safe-bash-core.ts
• .opencode/plugins/scope-before.ts
• .opencode/lib/backup-manager.ts
• .opencode/lib/__tests__/safe-bash-core.test.ts

Changes

1. Add shared shell write classifier — return read_only, known_write, opaque_write, or script_payload_write.

2. Heredoc/stdin inspection — for cat > / <<EOF redirections, capture or inspect payload before allowing. If content contains writes to workspace paths, block at payload creation time.

3. Temp script scanning — for /tmp/*.ts, /tmp/*.js, /tmp/*.py, /tmp/*.sh, scan content and target writes before execution. Extend script scanning from node *.ts/*.js to bun, python3, bash, sh, tsx, and /tmp/*.

4. Block payload creation if it stages writes to workspace files (.opencode/**, booking-backend/**, booking-frontend/**).

5. Remove path-aware eval allowance for framework writes — only .task_temp/_logs diagnostics can be written by shell. Remove // safe_bash: allow-write bypass; convert to "must use backup-aware repair wrapper."

6. Add backup_uuid requirement — before any framework file write, verify a backup_log row exists or create one atomically. Record backup_uuid on write audit events.

7. Remove broad "trusted script path" bypasses unless script is signed by config and declared in a DB-backed allowlist.

Acceptance Criteria

• cat > /tmp/impl.ts <<EOF with writeFileSync(".opencode/...") is blocked at creation
• bun /tmp/impl.ts is blocked even if creation happened before the fix
• python3 <<EOF open(".opencode/...","w") is blocked
• safe_edit still succeeds and creates a backup_log row
• Today's log evidence (scope-before-runtime.log:4214, 4481) of payload staging is prevented

Testing

bun test .opencode/lib/__tests__/safe-bash-core.test.ts