The Masonic handshake McCain is using is called The "MA-HA-BONE" REAL GRIP OF A MASTER MASON (HANDSHAKE). You can see it here.
McCain is sending code to the Millions of Masons on the planet that he needs their help and support by flashing that code.
Coded messages are used all the time. Guess who's been using them via released messages?
Secret Masonic handshakes, passwords, grips and signs of Entered Apprentice, Fellowcraft Fellow Craft and Mason Degrees of Blue Lodge Freemasonry
The Mason firmly grasps the right hand of a fellow Mason. The thumbs of both hands are interlaced. The first Mason presses the tops of his fingers
against the wrist of the fellow Mason where it unites with the hand. The fellow Mason at the same time presses his fingers against the corresponding
part of the the first Mason's hand and the fingers of each are somewhat apart. This grip is also called the Strong Grip of the Master Mason or the
Lion's Paw. Instruction for this grip is given at the "graveside", after the candidate has been "raised".
Speaking to the candidate, the Worshipful Master says, "My Brother, I will now instruct you as to the manner of arriving at the real grip and word of
a Master Mason. As you are uninstructed, he who has hitherto answered for you will do so at this time. Give me the pass-grip of a Master Mason."
WM: Brother Senior Deacon.
SD: Worshipful Master.
WM: Will be you be off or from?
WM: From what and to what?
SD: From the pass-grip of a Master Mason to the real grip of the same.
WM: Pass. What is that?
SD: The real grip of a Master Mason, or lion's paw.
WM: Has it a name?
SD: It has.
WM: Will you give it to me?
SD: Place yourself in the proper position to receive it and I will.
WM: Mark the difference, my Brother, Heretofore your answer has been; I did not so receive it, neither will I so impart it. Now it is: Place
yourself in the proper position to receive it and I will.
WM: What is the proper position to receive it?
SD: On the Five Points of Fellowship.
WM: What are the Five Points of Fellowship?
SD: Foot to foot, knee to knee, breast to breast, hand to back, and cheek to cheek or mouth to ear. (Cand and WM are placing themselves on the Five
Points of Fellowship as the SD names them.)
(WM may have the cand begin, while still in position, ie., Cand: Ma. WM: Ha. Cand: Bone, being sure the candidate fully understands the word.)