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.
To work around the problem that the external special remote protocol does
not support keys containing spaces.
This commit was sponsored by Denis Dzyubenko on Patreon.
Added remote configuration settings annex-ignore-command and
annex-sync-command, which are dynamic equivilants of the annex-ignore
and annex-sync configurations.
For this I needed a new DynamicConfig infrastructure. Its implementation
should be as fast as before when there is no dynamic config, and it caches
so shell commands are only run once.
Note that annex-ignore-command exits nonzero when the remote should be ignored.
While that may seem backwards, it allows using the same command for it as
for annex-sync-command when you want to disable both.
This commit was sponsored by Trenton Cronholm on Patreon.
Can be used to override the default timestamps used in log files in the
git-annex branch. This is a dangerous environment variable; use with
caution.
Note that this only affects writing to the logs on the git-annex branch.
It is not used for metadata in git commits (other env vars can be set for
that).
There are many other places where timestamps are still used, that don't
get committed to git, but do touch disk. Including regular timestamps
of files, and timestamps embedded in some files in .git/annex/, including
the last fsck timestamp and timestamps in transfer log files.
A good way to find such things in git-annex is to get for getPOSIXTime and
getCurrentTime, although some of the results are of course false positives
that never hit disk (unless git-annex gets swapped out..)
So this commit does NOT necessarily make git-annex comply with some HIPPA
privacy regulations; it's up to the user to determine if they can use it in
a way compliant with such regulations.
Benchmarking: It takes 0.00114 milliseconds to call getEnv
"GIT_ANNEX_VECTOR_CLOCK" when that env var is not set. So, 100 thousand log
files can be written with an added overhead of only 0.114 seconds. That
should be by far swamped by the actual overhead of writing the log files
and making the commit containing them.
This commit was supported by the NSF-funded DataLad project.
* Added annex.resolvemerge configuration, which can be set to false to
disable the usual automatic merge conflict resolution done by git-annex
sync and the assistant.
* sync: Added --no-resolvemerge option.
Note that disabling merge conflict resolution is probably not a good idea
in a direct mode repo or adjusted branch. Since updates to both are done
outside the usual work tree, if it fails the tree is not left in a
conflicted state, and it would be hard to manually resolve the conflict.
Still, made annex.resolvemerge be supported in those cases for consistency.
This commit was sponsored by Riku Voipio.
orElse is great, but was not the right thing to use here because
waitTakeLock could retry for other reasons than the lock being held,
which made tryTakeLock fail when it shouldn't.
Instead, move the code to tryTakeLock and implement waitTakeLock using
tryTakeLock and retry.
(Also, in runTransfer, when checkSaneLock fails, dropLock to avoid leaking a
lock handle.)
This commit was supported by the NSF-funded DataLad project.
When built with concurrent-output 1.9, ssh password prompts will no longer
interfere with the -J display.
To avoid flicker, only done when ssh actually does need to prompt;
ssh is first run in batch mode and if that succeeds the connection is up
and no need to clear regions.
This commit was supported by the NSF-funded DataLad project.
Might want to remove this when it gets fixed, in case adjusted branches are
used in a repo with a great many refs, which would become unnecessarily
slow.
This commit was supported by the NSF-funded DataLad project.
Removed dependency on MissingH, instead depending on the split
library.
After laying groundwork for this since 2015, it
was mostly straightforward. Added Utility.Tuple and
Utility.Split. Eyeballed System.Path.WildMatch while implementing
the same thing.
Since MissingH's progress meter display was being used, I re-implemented
my own. Bonus: Now progress is displayed for transfers of files of
unknown size.
This commit was sponsored by Shane-o on Patreon.
Cryptonite is faster and allocates less, and I want to get rid of
MissingH use.
Note that the new dependency on memory is free; it's a dependency of
cryptonite.
This commit was supported by the NSF-funded DataLad project.
Moving toward dropping MissingH dep.
I think I've addressed the problem identified earlier in
09a66f702d. On Windows,
absPathFrom "/tmp/repo/xxx" "y/bar" would be "/tmp/repo/xxx\\y/bar",
which then confuses relPathDirToFile. Fixed by converting to unix (git)
style paths.
Also, relPathDirToFile was splitting only on \\ on windows and not /
which broke the example in 09a66f702d of
relPathDirToFile (absPathFrom "/tmp/repo/xxx" "y/bar") "/tmp/repo/.git/annex/objects/xxx"
Now, on windows, that will yield "..\\..\\..\\.git/annex/objects/xxx"
which once converted to unix style paths is what we want.
When ssh connection caching is enabled (and when GIT_ANNEX_USE_GIT_SSH is
not set), only one ssh password prompt will be made per host, and only one
ssh password prompt will be made at a time.
This also fixes a race in prepSocket's stale ssh connection stopping
when run with -J. It was possible for one thread to start a cached ssh
connection, and another thread to immediately stop it, resulting in excess
connections being made.
This commit was supported by the NSF-funded DataLad project.
This is necessary because as feared, the extra -n parameter that git-annex
passes breaks uses of these environment variables that expect exactly the
parameters that git passes.
For example, see https://github.com/datalad/datalad/issues/1456
It would of course be possible to pre-close stdin before running ssh so not
needing the -n, and I think that would not even break ssh's password
caching. But it would probably involve a lot of work, possibly would need
to deal with some layering violations, and would be error-prone. The really
clean fix would be to make all the ssh stuff return a CreateProcess, which
could have the handle closed when appropriate, but that would be a large
reworing of the code base.
This commit was supported by the NSF-funded DataLad project.
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.
It was distributing jobs to remotes that were not being used by any other
job. But, suppose that there are only 2 remotes, and -J10. In such a case,
the first 2 downloads would be distributed amoung the 2 remotes, but
the other 8 would all go to remote #1. Improved by keeping a counter
of how many jobs are assigned to a remote, and prefer remotes with fewer
jobs.
Note use of Data.Map.Strict to avoid blowing up space. I kept the
bang-patterns as-is, although probably not needed with Data.Map.Strict.
This commit was sponsored by Jack Hill on Patreon.
* init: When annex.securehashesonly has been set with git-annex config,
copy that value to the annex.securehashesonly git config.
* config --set: As well as setting value in git-annex branch,
set local gitconfig. This is needed especially for
annex.securehashesonly, which is read only from local gitconfig and not
the git-annex branch.
doc/todo/sha1_collision_embedding_in_git-annex_keys.mdwn has the
rationalle for doing it this way. There's no perfect solution; this
seems to be the least-bad one.
This commit was supported by the NSF-funded DataLad project.
This avoids sending all the data to a remote, only to have it reject it
because it has annex.securehashesonly set. It assumes that local and
remote will have the same annex.securehashesonly setting in most cases.
If a remote does not have that set, and local does, the remote won't get
some content it would otherwise accept.
Also avoids downloading data that will not be added to the local object
store due to annex.securehashesonly.
Note that, while encrypted special remotes use a GPGHMAC key variety,
which is not collisiton resistent, Transfers are not used for such
keys, so this check is avoided. Which is what we want, so encrypted
special remotes still work.
This commit was sponsored by Ewen McNeill.
Added --securehash option to match files using a secure hash function, and
corresponding securehash preferred content expression.
This commit was sponsored by Ethan Aubin.
Cryptographically secure hashes can be forced to be used in a repository,
by setting annex.securehashesonly. This does not prevent the git repository
from containing files with insecure hashes, but it does prevent the content
of such files from being pulled into .git/annex/objects from another
repository.
We want to make sure that at no point does git-annex accept content into
.git/annex/objects that is hashed with an insecure key. Here's how it
was done:
* .git/annex/objects/xx/yy/KEY/ is kept frozen, so nothing can be
written to it normally
* So every place that writes content must call, thawContent or modifyContent.
We can audit for these, and be sure we've considered all cases.
* The main functions are moveAnnex, and linkToAnnex; these were made to
check annex.securehashesonly, and are the main security boundary
for annex.securehashesonly.
* Most other calls to modifyContent deal with other files in the KEY
directory (inode cache etc). The other ones that mess with the content
are:
- Annex.Direct.toDirectGen, in which content already in the
annex directory is moved to the direct mode file, so not relevant.
- fix and lock, which don't add new content
- Command.ReKey.linkKey, which manually unlocks it to make a
copy.
* All other calls to thawContent appear safe.
Made moveAnnex return a Bool, so checked all callsites and made them
deal with a failure in appropriate ways.
linkToAnnex simply returns LinkAnnexFailed; all callsites already deal
with it failing in appropriate ways.
This commit was sponsored by Riku Voipio.
Where before the "name" of a key and a backend was a string, this makes
it a concrete data type.
This is groundwork for allowing some varieties of keys to be disabled
in file2key, so git-annex won't use them at all.
Benchmarks ran in my big repo:
old git-annex info:
real 0m3.338s
user 0m3.124s
sys 0m0.244s
new git-annex info:
real 0m3.216s
user 0m3.024s
sys 0m0.220s
new git-annex find:
real 0m7.138s
user 0m6.924s
sys 0m0.252s
old git-annex find:
real 0m7.433s
user 0m7.240s
sys 0m0.232s
Surprising result; I'd have expected it to be slower since it now parses
all the key varieties. But, the parser is very simple and perhaps
sharing KeyVarieties uses less memory or something like that.
This commit was supported by the NSF-funded DataLad project.
sync: When syncing with a local repository located on a crippled
filesystem, run the post-receive hook there, since it wouldn't get run
otherwise. This makes pushing to repos on FAT-formatted removable drives
update them when receive.denyCurrentBranch=updateInstead.
Made Remote.Git export onLocal, which was cleaned up to not have so many
caveats about its use.
This commit was sponsored by Jeff Goeke-Smith on Patreon.
* Added post-recieve hook, which makes updateInstead work with direct
mode and adjusted branches.
* init: Set up the post-receive hook.
This commit was sponsored by Fernando Jimenez 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.
import: --deduplicate and --skip-duplicates were implemented inneficiently;
they unncessarily hashed each file twice. They have been improved to only
hash once.
The new approach is to lock down (minimally) and hash files, and then
reuse that information when importing them.
This was rather tricky, especially in detecting changes to files while
they are being imported.
The output of import changed slightly. While before it silently skipped
over files with eg --skip-duplicates, now it shows each file as it starts
to act on it. Since every file is hashed first thing, it would otherwise
not be clear what file import is chewing on. (Actually, it wasn't clear
before when any of the duplicates switches were used.)
This commit was sponsored by Alexander Thompson on Patreon.
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.
Turns out that Data.List.Utils.split is slow and makes a lot of
allocations. Here's a much simpler single character splitter that behaves
the same (even in wacky corner cases) while running in half the time and
75% the allocations.
As well as being an optimisation, this helps move toward eliminating use of
missingh.
(Data.List.Split.splitOn is nearly as slow as Data.List.Utils.split and
allocates even more.)
I have not benchmarked the effect on git-annex, but would not be surprised
to see some parsing of eg, large streams from git commands run twice as
fast, and possibly in less memory.
This commit was sponsored by Boyd Stephen Smith Jr. on Patreon.
Any config names can be set using this; git-annex commands will only look
at specific ones that make sense and are worth the overhead of querying the
branch.
This might also be useful for storing whatever other config-type stuff the
user might want to shove into the git-annex branch.
This commit was sponsored by Jochen Bartl on Patreon.
Revert ServerAliveInterval change in 6.20161111, which caused problems
with too many old versions of ssh and unusual ssh configurations.
It should have not been needed anyway since ssh is supposted to
have TCPKeepAlive enabled by default.
Added to change notification to P2P protocol.
Switched to a TBChan so that a single long-running thread can be
started, and serve perhaps intermittent requests for change
notifications, without buffering all changes in memory.
The P2P runner currently starts up a new thread each times it waits
for a change, but that should allow later reusing a thread. Although
each connection from a peer will still need a new watcher thread to run.
The dependency on stm-chans is more or less free; some stuff in yesod
uses it, so it was already indirectly pulled in when building with the
webapp.
This commit was sponsored by Francois Marier on Patreon.
