Except as authorized by this part, no Corporation funds shall be used to provide legal assistance in an action in the nature of habeas corpus collaterally attacking a criminal conviction if the action

(a) Is brought against an officer of a court, a law enforcement official, or a custodian of an institution for persons convicted of crimes; and

(b) Alleges that the conviction is invalid because of any alleged acts or failures to act by an officer of a court or a law enforcement official.