@schovest/pi-sudo-helper

Sudo password helper for the Pi coding agent. When the agent runs a sudo command through the bash tool, a masked password dialog pops up; the password is injected via SUDO_ASKPASS + a FIFO in /dev/shm (tmpfs) — it never touches disk, process arguments, or the agent's context.

Install

pi install npm:@schovest/pi-sudo-helper

Restart your Pi session.

How it works

1. On every bash tool_call, the command is scanned for sudo usage
2. A sudo -n true precheck skips the dialog while the sudo timestamp is still valid
3. A FIFO + askpass script are created under /dev/shm (permissions 0600 / 0700)
4. A masked password dialog takes over input; the typed password is XOR-encrypted in memory
5. On submit, only the first sudo is rewritten to SUDO_ASKPASS='<script>' sudo -A; nested sudos run as root and no longer need a password, so one authentication covers sudo bash -c '…' wrapping arbitrary inner commands
6. Temp resources are cleaned up when the tool call finishes

Command details

The dialog shows the exact command about to run as root above the password input, so you always know what you are authorizing. Collapsed by default to at most 3 logical lines (over-long lines truncated with …, plus a ⏷ 还有 N 行 footer). Tab expands the full command with keyboard scrolling — ↑/↓ one line, PgUp/PgDn a page, position shown as x–y/z 行; Tab again collapses. Mouse-wheel SGR sequences are handled defensively (the host does not enable terminal mouse reporting, so wheel events normally never arrive).

Scroll keys never leak to the underlying session: while the overlay dialog is focused, pi delivers all input exclusively to it, and focus is restored automatically on close — no global hooks, nothing to undo.

Input timeout

The password dialog cancels itself automatically after 120 seconds without input, so a forgotten dialog can never block the session indefinitely. A timed-out dialog blocks the tool call with an explanatory reason (the command is not executed and left unmodified); just re-issue the command to try again.

Reactive failure hints

No standing prompt is injected. If a sudo command fails and the original command shows a structural problem (multiple bare sudos, sudo -n probing, double-quoted sudo bash -c "…"), the tool result gets a short hint appended — the error snippet plus a suggestion to use sudo bash -c '<entire command>' with single quotes. Well-formed commands that fail for their own reasons stay silent.

Security

• Never persisted — the FIFO lives on /dev/shm tmpfs, pure RAM
• Never visible to ps / /proc — the password travels through a kernel pipe, not argv or environ
• Never exposed to the agent — the session records the original command; the agent only sees the command and its result
• Never a plain string in the heap — keystrokes are XOR-encrypted into a SecureBuffer with a random per-byte key; plaintext exists only inside a Buffer for the duration of a single write() and is zero-filled immediately after
• Wiped after use — buffers are physically zeroed, temp files unlinked

License

MIT