tree df779480cf3c30556ad3986d47502b9ec495b899
parent b8dd1d9e78c0ce14268aa38e472c0ee7a0e53bc5
author David Zeuthen <zeuthen@chromium.org> 1385510901 -0800
committer chrome-internal-fetch <chrome-internal-fetch@google.com> 1386303621 +0000

Delete p2p file if metadata or payload verification fails.

Currently, if metadata or payload verification fails we don't delete
the p2p file. In the payload verification case, this is especially
problematic as other devices may pick up the bad (and complete)
payload still being shared, fail themselves, and then continue to
propagate the badness. The metadata verification case is slightly less
bad, since we only leave a .tmp file around in /var/cache/p2p.

Note that this problem never manifest itself unless someone
deliberately injects a bad payload. The severity is additionally
mitigated by the fact that p2p will turn itself off after ten update
attempts or two wall-clock days, whichever comes first.

I noticed this while working on CL:177631.

This CL fixes the problem. I verified the fix by serving a payload in
the following way:

Fail metadata verification:

 $ ./devserver.py --test_image                  \
     --private_key                              \
       ../update_engine/unittest_key.pem        \
     --private_key_for_metadata_hash_signature  \
       ../update_engine/unittest_key.pem        \
     --public_key                               \
       ../update_engine/unittest_key2.pub.pem

Fail payload verification:

 $ ./devserver.py --test_image                  \
     --private_key                              \
       ../update_engine/unittest_key.pem        \
     --private_key_for_metadata_hash_signature  \
       ../update_engine/unittest_key2.pem       \
     --public_key                               \
       ../update_engine/unittest_key2.pub.pem

to a device with p2p enabled and ensured that the p2p files were
deleted on failure.

BUG=chromium:323733
TEST=Manually tested, see above.

Change-Id: Ieb439972f5415727920ff5b0c22dbb86503f911c
Reviewed-on: https://chromium-review.googlesource.com/178132
Reviewed-by: Chris Sosa <sosa@chromium.org>
Commit-Queue: David Zeuthen <zeuthen@chromium.org>
Tested-by: David Zeuthen <zeuthen@chromium.org>