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 am: b21b92b386 am: 8a51334062  -s ours am: 67b69c05c6 am: 8f9e3c9bd9 am: 8953f919e4 am: d0bfa33c66
am: 4aa56ad477

Change-Id: Ife96e05de25d6feba52958f7c927285cea411ca6