So you don’t want to create a back door? Fine — give us the entire house.

That was the FBI’s implied threat to Apple, buried in a footnote in a legal brief this week, as the government’s demands for a “back door” into a dead terrorist’s locked iPhone heated up.

Apple has argued that forcing it to create new software to circumvent its security systems would create vulnerabilities for all iPhone users — and a burdensome workload for employees responding to government requests.

In its rebuttal late Thursday, the Department of Justice said Apple could instead hand over the entire source code for iOS as well as its closely guarded “private electronic signature” that gives access to it.

“The government did not seek to compel Apple to turn those over because it believed such a request would be less palatable to Apple,” the feds wrote in a footnote to the 35-page brief. “If Apple would prefer that course, however, that may provide an alternative that requires less labor by Apple programmers.”

The scary demand wouldn’t be unprecedented, the government added, noting that it had made a similar request in August 2013 in its crackdown on National Security Agency leaker Edward Snowden.

At the time, the FBI had attempted to force Lavabit, the secure messaging service used by Snowden, to hand over encryption keys so that it could monitor Snowden’s emails. When Lavabit’s owner Ladar Levison refused, he was sanctioned for contempt of court.

On Thursday, Apple lawyer Bruce Sewell blasted the government’s brief as a “smear,” calling it “offensive” and “desperate.”