Check for integer overflow when HMAC key length as bits cannot fit in an unsigned int.

Check for integer overflow when HMAC key length as bits cannot fit in an unsigned int.

Committed: https://crrev.com/42e82923357fd24d2bd0e028d13f317c0b9474a7
Cr-Commit-Position: refs/heads/master@{#292203}

[eroman, 2014-08-26 22:19:35]

eroman@chromium.org changed reviewers:
+ rsleevi@chromium.org

[Ryan Sleevi, 2014-08-27 17:11:28]

lgtm

[eroman, 2014-08-27 17:33:31]

The CQ bit was checked by eroman@chromium.org

[commit-bot: I haz the power, 2014-08-27 17:33:49]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/eroman@chromium.org/508793002/1

[commit-bot: I haz the power, 2014-08-27 18:43:01]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_chromium_gn_rel on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[commit-bot: I haz the power, 2014-08-27 19:10:19]

Committed patchset #1 (id:1) as 0f70a4370ddf412af034ad15efc9effcedcd1ab9

[commit-bot: I haz the power, 2014-09-10 02:53:22]

Patchset 1 (id:??) landed as
https://crrev.com/42e82923357fd24d2bd0e028d13f317c0b9474a7
Cr-Commit-Position: refs/heads/master@{#292203}