On 07.09.2013 11:33, Andrey Borzenkov wrote: > So just use another environment block for untrusted variables, that's > all. I do not see why any change in sources is required. Trouble is that right now we unconditionally load all variables from block, whether trusted or not. So by modifying untrusted but loaded block you can override core variables i.a. check_signatures. That's why some ability to filter is required.