While the commits contained in the single static-delta file are signed so
we can check them and operate on trusted data, the superblock isn't signed
in any way, so it end up operating on untrusted data to:
1. actually find where the trusted data is, and
2. check whether the update is fit for the current device by looking at
the collection id stored in the metadata
This commit generates signatures of all static data, and concatenate them
to the existing static delta format, i.e. as a GVariant layout `a{sv}ay`
where
- a{sv}: signatures
- ay: existing delta variant
Signed-off-by: Frédéric Danis <frederic.danis@collabora.com>
This loads and makes a digest for a delta superblock. The previous
code was used when generating the deltas section in the summary
file. This changes nothing, but is in preparation for using similar
formats in a separate delta index file.
SPDX License List is a list of (common) open source
licenses that can be referred to by a “short identifier”.
It has several advantages compared to the common "license header texts"
usually found in source files.
Some of the advantages:
* It is precise; there is no ambiguity due to variations in license header
text
* It is language neutral
* It is easy to machine process
* It is concise
* It is simple and can be used without much cost in interpreted
environments like java Script, etc.
* An SPDX license identifier is immutable.
* It provides simple guidance for developers who want to make sure the
license for their code is respected
See http://spdx.org for further reading.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Closes: #1439
Approved by: cgwalters
We added a `.dir-locals.el` in commit: 9a77017d87
There's no need to have it per-file, with that people might think
to add other editors, which is the wrong direction.
Closes: #1206
Approved by: jlebon
This is a follow up to conversation on list - in practice, if we're
backing away from summary signing, then it makes sense to remove the
special casing for checksums in deltas around summary signatures.
This is also related to the recent change to enable GPG checking for
commits in deltas - now we have a more coherent story between the
previous pull path and deltas.
I didn't do any performance checking, and while it's slightly annoying
that we're now doing sha256 on the delta content twice (once for the
part and once per object)...sha256 is pretty fast, I think most users
are I/O bound anyways, and it'd drop even farther if we started using
openssl.
Closes: #612
Approved by: jlebon
I often want to have "idempotent" systems that iterate to a known
state. If after generating a commit, the system is interrupted, I'd
like the next run to still generate a delta. But we don't want to
regenerate if one exists, hence this option.
Closes: #375
Approved by: jlebon
If the average object size is greater than 4GiB, let's assume we're
dealing with opposite endianness. I'm fairly confident no one is
going to be shipping peta- or exa- byte size ostree deltas, period.
Past the gigabyte scale you really want bittorrent or something.
Now we display stats on the individual parts, such as the blob size
and the number of each type of opcode. Most interesting to me is
things like how many bsdiff opcodes there are vs new objects, etc.
We had code to deal with opening/checksumming/decompressing static
deltas in a few places. I'd like to teach `ostree static-delta show`
how to display more information, and this will allow it to just use
`_ostree_static_delta_part_open()` too.
Right now though, almost all of the details of deltas are private, so
we can't do the "honest thing" and have the command line just use the
shared library.
Eventually some of this should appear in the API, but for now add
command line which is useful for debugging.
The previous diff algorithm was file tree based, and only looked
at modified files that lived at the same path.
However, components like the Linux kernel have versioned
subdirectories, e.g. /usr/lib/modules/$kver/.../ext4.ko. We want to
be able to detect these "modified renames" so that we can compute
diffs (rollsum, bsdiff).
This does an rsync-style prepared delta basically. On my test data,
it shaves ~6MB of uncompressed data. Not a huge amount, but I expect
this to be more useful for things like binaries which embed data, etc.
There's still some silliness here, but there is now only one opcode
open-splice-and-close, that writes a single chunk from the payload.
This is really all we need for metadata, and small content objects are
also fine with this.
We get some deduplication between content objects by creating a
dictionary for (uid,gid,mode) tuples and xattrs.
This still keeps the operation/payload code in, so we could do
rollsums in a future update easily.
This has a very basic level of functionality (deltas can be generated,
and applied offline). There is only some stubbed out pull code to
fetch them via HTTP.
But, better to commit this now and improve it from a known starting
point, rather than have it languish in a branch.
Frédéric Danis
Alexander Larsson
Marcus Folkesson
Philip Withnall
Colin Walters
Giuseppe Scrivano