Yes, according to Miles' post, Davis was signing that Congressional authorization on May 6th. Again the Southern States appear to be holding to the Constitutional Provisions and the letter oof the law, as apposed to Lincoln and the northern legislators.

Lincoln had (as far as I know) no constitutional authority to call for however many troops he needed to invade the southern states. Whereas Davis was calling for his troops for the purpose of the defence of the south. I know of no plans that Davis or the Confederate Congress had to invade the Northern states at this time.