There's nothing saying it's "illegal" eg in the "insecure" area, but I
guarantee you if you call up the MSP unit at logan they will tell you
"NO you will get arrested" (on what charge I don't know) based on
prior experience dealing with them. Don't even bother asking them
gun law questions, you'll get a wrong answer.
I would wager that "Concealed" is the operative term here.
A number of years back, attorney William Cloran came to our gun club to speak. He said that there was a regulation against carrying on Massport property. I have never seen any citations to that affect or heard the same from any other sources. That doesn't mean it doesn't exist, just that I haven't been able to find it.
I was not impressed with some of Mr. Cloran's recommendations.