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

Change-Id: I87b102e92e9ee2bc49af6b7c8ec4d0a48894f732