#!/bin/sh
# Voicemail PIN check for PINs changed from the phone (app_voicemail externpasscheck).
# Args: mailbox context oldpin newpin. Prints VALID or INVALID. Same rules as the api
# (crypto/secrets.ts isTrivialPin): 4-10 digits, not one digit repeated, not a run like
# 1234 or 4321, not the extension repeated.
box=$1
pin=$4
case $pin in
  '' | *[!0-9]*) echo INVALID; exit 0 ;;
esac
len=${#pin}
if [ "$len" -lt 4 ] || [ "$len" -gt 10 ]; then echo INVALID; exit 0; fi
first=$(printf %.1s "$pin")
if [ -z "$(printf %s "$pin" | tr -d "$first")" ]; then echo INVALID; exit 0; fi
case 01234567890 in *"$pin"*) echo INVALID; exit 0 ;; esac
case 09876543210 in *"$pin"*) echo INVALID; exit 0 ;; esac
rep=$box
while [ ${#rep} -lt "$len" ]; do rep=$rep$box; done
if [ -n "$box" ] && [ "$(printf %s "$rep" | cut -c1-"$len")" = "$pin" ]; then echo INVALID; exit 0; fi
echo VALID