@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

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