The old VerifyFirmware function (now called VerifyFirmwareImage) works on the FirmwareImage structure. This CL adds a verification function which can be used directly on packed binary verified boot firmware blobs. This function can be used as the reference implementation for verified boot in firmware. In addition, all functions that work on FirmwareImage structure have been renames to distinguish them from those which work on binary firmware blobs.
In addition, this adds some new crypto utility functions and refactors old ones.
BUG=670
TEST=Added tests for the new function and they pass.
Review URL: http://codereview.chromium.org/650105
A DigestContext structure now wraps state for all the SHA* algorithms. Replaced the old SHA*_file functions to use these new wrappers. Also moved the digest utility functions from tests/ to crypto/.
BUG=670
TEST=Modified existing tests to use the new wrappers and they pass.
Review URL: http://codereview.chromium.org/579007
