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

Change-Id: I32c16f13987f4b1b1c46af948c1a724d8225c0cc