Several special remotes verify content while it is being retrieved,
avoiding a separate checksum pass. They are: S3, bup, ddar, and
gcrypt (with a local repository).
Not done when using chunking, yet.
Complicated by Retriever needing to change to be polymorphic. Which in turn
meant RankNTypes is needed, and also needed some code changes. The
change in Remote.External does not change behavior at all but avoids
the type checking failing because of a "rigid, skolem type" which
"would escape its scope". So I refactored slightly to make the type
checker's job easier there.
Unfortunately, directory uses fileRetriever (except when chunked),
so it is not amoung the improved ones. Fixing that would need a way for
FileRetriever to return a Verification. But, since the file retrieved
may be encrypted or chunked, it would be extra work to always
incrementally checksum the file while retrieving it. Hm.
Some other special remotes use fileRetriever, and so don't get incremental
verification, but could be converted to byteRetriever later. One is
GitLFS, which uses downloadConduit, which writes to the file, so could
verify as it goes. Other special remotes like web could too, but don't
use Remote.Helper.Special and so will need to be addressed separately.
Sponsored-by: Dartmouth College's DANDI project
This is to support, eg a borg repo as a special remote, which is
populated not by running git-annex commands, but by using borg. Then
git-annex sync lists the content of the remote, learns which files are
annex objects, and treats those as present in the remote.
So, most of the import machinery is reused, to a new purpose. While
normally importtree maintains a remote tracking branch, this does not,
because the files stored in the remote are annex object files, not
user-visible filenames. But, internally, a git tree is still generated,
of the files on the remote that are annex objects. This tree is used
by retrieveExportWithContentIdentifier, etc. As with other import/export
remotes, that the tree is recorded in the export log, and gets grafted
into the git-annex branch.
importKey changed to be able to return Nothing, to indicate when an
ImportLocation is not an annex object and so should be skipped from
being included in the tree.
It did not seem to make sense to have git-annex import do this, since
from the user's perspective, it's not like other imports. So only
git-annex sync does it.
Note that, git-annex sync does not yet download objects from such
remotes that are preferred content. importKeys is run with
content downloading disabled, to avoid getting the content of all
objects. Perhaps what's needed is for seekSyncContent to be run with these
remotes, but I don't know if it will just work (in particular, it needs
to avoid trying to transfer objects to them), so I skipped that for now.
(Untested and unused as of yet.)
This commit was sponsored by Jochen Bartl on Patreon.
This handles all createProcessSuccess callers, and aside from process
pools, the complete conversion of all process running to async exception
safety should be complete now.
Also, was able to remove from Utility.Process the old API that I now
know was not a good idea. And proof it was bad: The code size went *down*,
despite there being a fair bit of boilerplate for some future API to
reduce.
This handles all sites where checkSuccessProcess/ignoreFailureProcess
is used, except for one: Git.Command.pipeReadLazy
That one will be significantly more work to convert to bracketing.
(Also skipped Command.Assistant.autoStart, but it does not need to
shut down the processes it started on exception because they are
git-annex assistant daemons..)
forceSuccessProcess is done, except for createProcessSuccess.
All call sites of createProcessSuccess will need to be converted
to bracketing.
(process pools still todo also)
When storing content on remote fails, always display a reason why.
Since the Storer used by special remotes already did, this mostly affects
git remotes, but not entirely. For example, if git-lfs failed to connect to
the endpoint, it used to silently return False.
That had almost no benefit at all, and complicated things quite a lot.
What I proably wanted this to be was something like ResourceT, but it
was not. The few remotes that actually need some preparation done only
once and reused used a MVar and not Preparer.
Fix serious regression in gcrypt and encrypted git-lfs remotes.
Since version 7.20200202.7, git-annex incorrectly stored content
on those remotes without encrypting it.
Problem was, Remote.Git enumerates all git remotes, including git-lfs
and gcrypt. It then dispatches to those. So, Remote.List used the
RemoteConfigParser from Remote.Git, instead of from git-lfs or gcrypt,
and that parser does not know about encryption fields, so did not
include them in the ParsedRemoteConfig. (Also didn't include other
fields specific to those remotes, perhaps chunking etc also didn't
get through.)
To fix, had to move RemoteConfig parsing down into the generate methods
of each remote, rather than doing it in Remote.List.
And a consequence of that was that ParsedRemoteConfig had to change to
include the RemoteConfig that got parsed, so that testremote can
generate a new remote based on an existing remote.
(I would have rather fixed this just inside Remote.Git, but that was not
practical, at least not w/o re-doing work that Remote.List already did.
Big ugly mostly mechanical patch seemed preferable to making git-annex
slower.)
This is a first step toward that goal, using the ProposedAccepted type
in RemoteConfig lets initremote/enableremote reject bad parameters that
were passed in a remote's configuration, while avoiding enableremote
rejecting bad parameters that have already been stored in remote.log
This does not eliminate every place where a remote config is parsed and a
default value is used if the parse false. But, I did fix several
things that expected foo=yes/no and so confusingly accepted foo=true but
treated it like foo=no. There are still some fields that are parsed with
yesNo but not not checked when initializing a remote, and there are other
fields that are parsed in other ways and not checked when initializing a
remote.
This also lays groundwork for rejecting unknown/typoed config keys.
This solves the problem of sameas remotes trampling over per-remote
state. Used for:
* per-remote state, of course
* per-remote metadata, also of course
* per-remote content identifiers, because two remote implementations
could in theory generate the same content identifier for two different
peices of content
While chunk logs are per-remote data, they don't use this, because the
number and size of chunks stored is a common property across sameas
remotes.
External special remote had a complication, where it was theoretically
possible for a remote to send SETSTATE or GETSTATE during INITREMOTE or
EXPORTSUPPORTED. Since the uuid of the remote is typically generate in
Remote.setup, it would only be possible to pass a Maybe
RemoteStateHandle into it, and it would otherwise have to construct its
own. Rather than go that route, I decided to send an ERROR in this case.
It seems unlikely that any existing external special remote will be
affected. They would have to make up a git-annex key, and set state for
some reason during INITREMOTE. I can imagine such a hack, but it doesn't
seem worth complicating the code in such an ugly way to support it.
Unfortunately, both TestRemote and Annex.Import needed the Remote
to have a new field added that holds its RemoteStateHandle.
In 40ecf58d4b I changed the license of code I
wrote from GPL to AGPL. But, two files containing code I wrote combined
with code by others were updated to say their license is AGPL, while in
fact part of it was (the code I wrote) but part remained under the original
license (the code written by others).
Remote/Ddar.hs is now changed entirely back to GPL 3.
Annex/DirHashes.hs stays AGPL, but I broke out Utility/MD5.hs with the code
not written by me, and corrected its license statement to GPL-2, which
is the actual version of the GPL included with the code in its original
distribution at http://www.cs.ox.ac.uk/people/ian.lynagh/md5/
This does not change the overall license of the git-annex program, which
was already AGPL due to a number of sources files being AGPL already.
Legally speaking, I'm adding a new license under which these files are
now available; I already released their current contents under the GPL
license. Now they're dual licensed GPL and AGPL. However, I intend
for all my future changes to these files to only be released under the
AGPL license, and I won't be tracking the dual licensing status, so I'm
simply changing the license statement to say it's AGPL.
(In some cases, others wrote parts of the code of a file and released it
under the GPL; but in all cases I have contributed a significant portion
of the code in each file and it's that code that is getting the AGPL
license; the GPL license of other contributors allows combining with
AGPL code.)
What these generate is not really suitable to be used as a filename,
which is why keyFile and fileKey further escape it. These are just
serializing Keys.
Also removed a quickcheck test that was very unlikely to test anything
useful, since it relied on random chance creating something that looks
like a serialized key. The other test is sufficient for testing what
that was intended to test anyway.
Does nothing yet.
Considered making bup readonly, but while the content can't be removed,
it is able to delete a branch, so didn't.
This commit was supported by the NSF-funded DataLad project.
This will be used to protect against CVE-2018-10859, where an encrypted
special remote is fed the wrong encrypted data, and so tricked into
decrypting something that the user encrypted with their gpg key and did
not store in git-annex.
It also protects against CVE-2018-10857, where a remote follows a http
redirect to a file:// url or to a local private web server. While that's
already been prevented in git-annex's own use of http, external special
remotes, hooks, etc use other http implementations and could still be
vulnerable.
The policy is not yet enforced, this commit only adds the appropriate
metadata to remotes.
This commit was sponsored by Boyd Stephen Smith Jr. on Patreon.
This is groundwork for letting a repo be instantiated the first time
it's actually used, instead of at startup.
The only behavior change is that some old special cases for xmpp remotes
were removed. Where before git-annex silently did nothing with those
no-longer supported remotes, it may now fail in some way.
The additional IO action should have no performance impact as long as
it's simply return.
This commit was sponsored by Boyd Stephen Smith Jr. on Patreon
git annex testremote passes.
exportree not implemented yet, although the documentation talks about it,
since it will be the main way this remote will be used.
The adb push/pull progress is displayed for now; it would be better
to consume it and use it to update the git-annex progress bar.
This commit was sponsored by andrea rota.
Don't allow "exporttree=yes" to be set when the special remote
does not support exports. That would be confusing since the user would
set up a special remote for exports, but `git annex export` to it would
later fail.
This commit was supported by the NSF-funded DataLad project.
This will allow disabling exports for remotes that are not configured to
allow them. Also, exportSupported will be useful for the external
special remote to probe.
This commit was supported by the NSF-funded DataLad project
Implemented so far for the directory special remote.
Several remotes don't make sense to export to. Regular Git remotes,
obviously, do not. Bup remotes almost certianly do not, since bup would
need to be used to extract the export; same store for Ddar. Web and
Bittorrent are download-only. GCrypt is always encrypted so exporting to
it would be pointless. There's probably no point complicating the Hook
remotes with exporting at this point. External, S3, Glacier, WebDAV,
Rsync, and possibly Tahoe should be modified to support export.
Thought about trying to reuse the storeKey/retrieveKeyFile/removeKey
interface, rather than adding a new interface. But, it seemed better to
keep it separate, to avoid a complicated interface that sometimes
encrypts/chunks key/value storage and sometimes users non-key/value
storage. Any common parts can be factored out.
Note that storeExport is not atomic.
doc/design/exporting_trees_to_special_remotes.mdwn has some things in
the "resuming exports" section that bear on this decision. Basically,
I don't think, at this time, that an atomic storeExport would help with
resuming, because exports are not key/value storage, and we can't be
sure that a partially uploaded file is the same content we're currently
trying to export.
Also, note that ExportLocation will always use unix path separators.
This is important, because users may export from a mix of windows and
unix, and it avoids complicating the API with path conversions,
and ensures that in such a mix, they always use the same locations for
exports.
This commit was sponsored by Bruno BEAUFILS on Patreon.
Security fix: Disallow hostname starting with a dash, which would get
passed to ssh and be treated an option. This could be used by an attacker
who provides a crafted ssh url (for eg a git remote) to execute arbitrary
code via ssh -oProxyCommand.
No CVE has yet been assigned for this hole.
The same class of security hole recently affected git itself,
CVE-2017-1000117.
Method: Identified all places where ssh is run, by git grep '"ssh"'
Converted them all to use a SshHost, if they did not already, for
specifying the hostname.
SshHost was made a data type with a smart constructor, which rejects
hostnames starting with '-'.
Note that git-annex already contains extensive use of Utility.SafeCommand,
which fixes a similar class of problem where a filename starting with a
dash gets passed to a program which treats it as an option.
This commit was sponsored by Jochen Bartl on Patreon.
They are handled close the same as they are by git. However, unlike git,
git-annex sometimes needs to pass the -n parameter when using these.
So, this has the potential for breaking some setup, and perhaps there ought
to be a ANNEX_USE_GIT_SSH=1 needed to use these. But I'd rather avoid that
if possible, so let's see if anyone complains.
Almost all places where "ssh" was run have been changed to support the env
vars. Anything still calling sshOptions does not support them. In
particular, rsync special remotes don't. Seems that annex-rsync-transport
already gives sufficient control there.
(Fixed in passing: Remote.Helper.Ssh.toRepo used to extract
remoteAnnexSshOptions and pass them to sshOptions, which was redundant
since sshOptions also extracts those.)
This commit was sponsored by Jeff Goeke-Smith on Patreon.
... to avoid it consuming stdin that it shouldn't.
This fixes git-annex-checkpresentkey --batch remote, which didn't output
results for all keys passed into it.
Other git-annex commands that communicate with a remote over ssh may also
have been consuming stdin that they shouldn't have, which could have
impacted using them in eg, shell scripts. For example, a shell script
reading files from stdin and passing them to git annex drop would be
impacted by this bug, whenever git annex drop ran git-annex-shell
checkpresent, it would consume part/all of the stdin that the shell script
was supposed to consume.
Fixed by adding a ConsumeStdin parameter to Annex.Ssh.sshOptions, which
is used throughout git-annex to run ssh (in order for ssh connection
caching to work). Every call site was checked to see if it used
CreatePipe for stdin, and if not was marked NoConsumeStdin.
Most remotes have an idempotent setup that can be reused for
enableremote, but in a few cases, it needs to tell which, and whether
a UUID was provided to setup was used.
This is groundwork for making initremote be able to provide a UUID.
It should not change any behavior.
Note that it would be nice to make the UUID always be provided to setup,
and make setup not need to generate and return a UUID. What prevented
this simplification is Remote.Git.gitSetup, which needs to reuse the
UUID of the git remote when setting it up, and so has to return that
UUID.
This commit was sponsored by Thom May on Patreon.
ghc 8 added backtraces on uncaught errors. This is great, but git-annex was
using error in many places for a error message targeted at the user, in
some known problem case. A backtrace only confuses such a message, so omit it.
Notably, commands like git annex drop that failed due to eg, numcopies,
used to use error, so had a backtrace.
This commit was sponsored by Ethan Aubin.
Removed the instance LensGpgEncParams RemoteConfig because it encouraged
code that does not take the RemoteGitConfig into account.
RemoteType's setup was changed to take a RemoteGitConfig,
although the only place that is able to provide a non-empty one is
enableremote, when it's changing an existing remote. This led to several
folow-on changes, and got RemoteGitConfig plumbed through.
sshOptions is now designed for working out ssh options only, and may
insert the extra options it is given to the middle. So it is incorrect
to call it with the remote parameters at the end. Instead, append them
to its return value.
This half regressed in 5be7ba7, and presumably regressed fully when
sshOptions was changed some time later.
Now it suffices to run git remote add, followed by git-annex sync. Now the
remote is automatically initialized for use by git-annex, where before the
git-annex branch had to manually be pushed before using git-annex sync.
Note that this involved changes to git-annex-shell, so if the remote is
using an old version, the manual push is still needed.
Implementation required git-annex-shell be changed, so configlist can
autoinit a repository even when no git-annex branch has been pushed yet.
Unfortunate because we'll have to wait for it to get deployed to servers
before being able to rely on this change in the documentation.
Did consider making git-annex sync push the git-annex branch to repos that
didn't have a uuid, but this seemed difficult to do without complicating it
in messy ways.
It would be cleaner to split a command out from configlist to handle
the initialization. But this is difficult without sacrificing backwards
compatability, for users of old git-annex versions which would not use the
new command.
Now `git annex info $remote` shows info specific to the type of the remote,
for example, it shows the rsync url.
Remote types that support encryption or chunking also include that in their
info.
This commit was sponsored by Ævar Arnfjörð Bjarmason.
encryptionSetup must be called before setRemoteCredPair. Otherwise,
the RemoteConfig doesn't have the cipher in it, and so no cipher is used to
encrypt the embedded creds.
This is a security fix for non-shared encryption methods!
For encryption=shared, there's no security problem, just an
inconsistentency in whether the embedded creds are encrypted.
This is very important to get right, so used some types to help ensure that
setRemoteCredPair is only run after encryptionSetup. Note that the external
special remote bypasses the type safety, since creds can be set after the
initial remote config, if the external special remote program requests it.
Also note that IA remotes never use encryption, so encryptionSetup is not
run for them at all, and again the type safety is bypassed.
This leaves two open questions:
1. What to do about S3 and glacier remotes that were set up
using encryption=pubkey/hybrid with embedcreds?
Such a git repo has a security hole embedded in it, and this needs to be
communicated to the user. Is the changelog enough?
2. enableremote won't work in such a repo, because git-annex will
try to decrypt the embedded creds, which are not encrypted, so fails.
This needs to be dealt with, especially for ecryption=shared repos,
which are not really broken, just inconsistently configured.
Noticing that problem for encryption=shared is what led to commit
fbdeeeed5f, which tried to
fix the problem by not decrypting the embedded creds.
This commit was sponsored by Josh Taylor.
Added a mkUnavailable method, which a Remote can use to generate a version
of itself that is not available. Implemented for several, but not yet all
remotes.
This allows testing that checkPresent properly throws an exceptions when
it cannot check if a key is present or not. It also allows testing that the
other methods don't throw exceptions in these circumstances.
This immediately found several bugs, which this commit also fixes!
* git remotes using ssh accidentially had checkPresent return
an exception, rather than throwing it
* The chunking code accidentially returned False rather than
propigating an exception when there were no chunks and
checkPresent threw an exception for the non-chunked key.
This commit was sponsored by Carlo Matteo Capocasa.
Removed old extensible-exceptions, only needed for very old ghc.
Made webdav use Utility.Exception, to work after some changes in DAV's
exception handling.
Removed Annex.Exception. Mostly this was trivial, but note that
tryAnnex is replaced with tryNonAsync and catchAnnex replaced with
catchNonAsync. In theory that could be a behavior change, since the former
caught all exceptions, and the latter don't catch async exceptions.
However, in practice, nothing in the Annex monad uses async exceptions.
Grepping for throwTo and killThread only find stuff in the assistant,
which does not seem related.
Command.Add.undo is changed to accept a SomeException, and things
that use it for rollback now catch non-async exceptions, rather than
only IOExceptions.
This will allow special remotes to eg, open a http connection and reuse it,
while checking if chunks are present, or removing chunks.
S3 and WebDAV both need this to support chunks with reasonable speed.
Note that a special remote might want to cache a http connection across
multiple requests. A simple case of this is that CheckPresent is typically
called before Store or Remove. A remote using this interface can certianly
use a Preparer that eg, uses a MVar to cache a http connection.
However, it's up to the remote to then deal with things like stale or
stalled http connections when eg, doing a series of downloads from a remote
and other places. There could be long delays between calls to a remote,
which could lead to eg, http connection stalls; the machine might even
move to a new network, etc.
It might be nice to improve this interface later to allow
the simple case without needing to handle the full complex case.
One way to do it would be to have a `Transaction SpecialRemote cache`,
where SpecialRemote contains methods for Storer, Retriever, Remover, and
CheckPresent, that all expect to be passed a `cache`.
I tend to prefer moving toward explicit exception handling, not away from
it, but in this case, I think there are good reasons to let checkPresent
throw exceptions:
1. They can all be caught in one place (Remote.hasKey), and we know
every possible exception is caught there now, which we didn't before.
2. It simplified the code of the Remotes. I think it makes sense for
Remotes to be able to be implemented without needing to worry about
catching exceptions inside them. (Mostly.)
3. Types.StoreRetrieve.Preparer can only work on things that return a
Bool, which all the other relevant remote methods already did.
I do not see a good way to generalize that type; my previous attempts
failed miserably.
