Simple shell script that generates a base64-encoded BitTorrent Sync secret with arbitrary length parameter

btsync-secret.sh

#!/bin/bash -e
SECRET_SIZE=128
mkdir -p "$HOME/.local/tmp"
rm -f "$HOME/.local/tmp/btsync-secret".*
umask 0077
SECRET_FILE="`mktemp "$HOME/.local/tmp/btsync-secret.XXXXXXXXXX"`"
echo -n "Generating a $SECRET_SIZE-byte secret "
head --bytes=$SECRET_SIZE /dev/random > "$SECRET_FILE" &
while true; do
  CUR_SECRET_SIZE=`stat --format='%s' "$SECRET_FILE"`
  if [[ $CUR_SECRET_SIZE -eq $SECRET_SIZE ]]; then
    break
  fi
  sleep 1
  echo -n '.'
done
echo ' done'

# Encode first to Base32 and then to Base64 so that resulting secret looks pretty.
SECRET=`cat "$SECRET_FILE" | python -c "import sys;import base64; sys.stdout.write(base64.b32encode(sys.stdin.read()))"`
rm -f "$SECRET_FILE"
SECRET=`echo -n "$SECRET" | sed 's/=\+$//' | base64 -w 0 | sed 's/=\+$//'`
echo $SECRET

Is there a way to use these longer secrets in mac os x or windows clients? I presume your generated secret is used by the btsync config files you write for linux?