#!/bin/sh

PLAYREADY_HASH_FILE=/user/drm/drmcert
WIDEVINE_HASH_FILE=/user/widevine/drm.bin.sha1

verify_playready_drm_state()
{
  echo "Verifying PlayReady status"

  # /user/drm/drmcert is actually a hash of the PlayReady bin. The bin can only
  # change during a platform update, as it is mounted read-only, however if it
  # does change we need to invalidate (remove) the local read-write state.
  local drmcert="invalid"
  [ -e "$PLAYREADY_HASH_FILE" ] && read drmcert <$PLAYREADY_HASH_FILE

  local fscert="$(sha1sum /usr/local/licenses/playready.bin)"
  if [ "$drmcert" != "$fscert" ]; then
    echo "The PlayReady bin appears to have changed; invalidating local state"
    rm -rf /user/drm/*
    echo "$fscert" > $PLAYREADY_HASH_FILE
  fi

  echo "PlayReady verified"
}

verify_widevine_drm_state()
{
  echo "Verifying non-SAGE Widevine CENC status"

  # The non-SAGE Widevine CENC drm.bin is copied from a read-only mounted
  # location to a read-write location, and individualized for each box. As such,
  # it can become corrupt (e.g. if the flash fails), so we store a hash and
  # invalidate it if the hash no longer matches.
  local drmcert="invalid"
  [ -e "$WIDEVINE_HASH_FILE" ] && read drmcert <$WIDEVINE_HASH_FILE

  local fscert="$(sha1sum /user/widevine/drm.bin)"
  if [ "$drmcert" != "$fscert" ]; then
    echo "The Widevine bin appears to have changed; invalidating and recreating"
    rm -rf /user/widevine/drm.bin*
    cp -f /usr/local/licenses/drm.bin /user/widevine/drm.bin
    # Waitpower has logic to trigger the initialization of the drm.bin
    /app/client/waitpower --n
    fscert="$(sha1sum /user/widevine/drm.bin)"
    echo "$fscert" > $WIDEVINE_HASH_FILE
  fi

  echo "Widevine verified"
}

verify_playready_drm_state

verify_widevine_drm_state