AU: Add options to delta_generator to hash and sign generated payloads.

AU: Add options to delta_generator to hash and sign generated payloads.

To generate a SHA-256 hash for signing an unsigned payload use:

./delta_generator -in_file <unsigned_payload> \
  -out_hash_file <hash_for_signing> -signature_size <size>

To add a signature to an unsigned payload use:

./delta_generator -in_file <unsigned_payload> \
  -signature_file <signature> -out_file <signed_payload>

The size of the signature file must be exactly the same as the signature size
supplied while hashing the payload.

Also removed the -apply_delta option because it's replaced by the new -in_file
option -- if -in_file is specified with no other hashing/signing option, the
generator runs in delta application mode.

BUG=chromium-os:10872
TEST=manually ran delta_generator on payloads

Change-Id: Ie918239a4db607153932cc1907127790cf3179d3

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=da8c136

[petkov, 2011-01-13 19:53:40]

In a subsequent CL I'll try to include the delta_generator in some unit tests.

[adlr, 2011-01-13 20:42:37]

LGTM

in the future it would probably be good to have a verify option where you pass a
public key, but i don't think this CL should block on that.

http://codereview.chromium.org/6305002/diff/1/generate_delta_main.cc
File generate_delta_main.cc (right):

http://codereview.chromium.org/6305002/diff/1/generate_delta_main.cc#newcode30
generate_delta_main.cc:30: "Directory where the old rootfs is loop mounted
read-only.");
be consistent w/ adding a period to the end of help messages

[petkov, 2011-01-13 20:47:34]

Yes, that's exactly what I was planning to do -- add a verify option and use a
full hash/sign/verify cycle in a unit test.

I'll push this CL as is though -- it should enable the build team to add payload
signing to the release build.

http://codereview.chromium.org/6305002/diff/1/generate_delta_main.cc
File generate_delta_main.cc (right):

http://codereview.chromium.org/6305002/diff/1/generate_delta_main.cc#newcode30
generate_delta_main.cc:30: "Directory where the old rootfs is loop mounted
read-only.");
On 2011/01/13 20:42:37, adlr wrote:
> be consistent w/ adding a period to the end of help messages

Done.