DO NOT MERGE: Add a checker for signature boundary in verifier am: f616da1726 am: 5346da0220  -s ours am: a41cc29447  -s ours am: 051dfa7ec3  -s ours am: 94c8b5e5a6 am: 2b1bcab427  -s ours am: 37a5941440
am: ddca75fb0a

Change-Id: I8010afacf2d0299715cb3b11b81f31d6baca1083