This deals with the possible security problem that someone could make an
unusually low UUID and generate keys that are all constructed to hash to
a number that, mod the number of repositories in the group, == 0.
So balanced preferred content would always put those keys in the
repository with the low UUID as long as the group contains the
number of repositories that the attacker anticipated.
Presumably the attacker than holds the data for ransom? Dunno.
Anyway, the partial solution is to use HMAC (sha256) with all the UUIDs
combined together as the "secret", and the key as the "message". Now any
change in the set of UUIDs in a group will invalidate the attacker's
constructed keys from hashing to anything in particular.
Given that there are plenty of other things someone can do if they can
write to the repository -- including modifying preferred content so only
their repository wants files, and numcopies so other repositories drom
them -- this seems like safeguard enough.
Note that, in balancedPicker, combineduuids is memoized.
This works well, and it interoperates with gpg in my testing (although some
SOP commands might choose to use a profile that does not so caveat emptor).
Note that for creating the Cipher, gpg --gen-random is still used. SOP
does not have an eqivilant, and as long as the user has gpg around,
which seems likely, it doesn't matter that it uses gpg here, it's not being
used for encryption. That seemed better than implementing a second way
to get high quality entropy, at least for now.
The need for the sop command to run in an empty directory has each call
to encrypt and decrypt creating a new temporary directory. That is some
unncessary overhead, though probably swamped by the overhead of running
the sop command. This could be improved in the future by passing an
already empty directory to them, or a sufficiently empty directory
(.git/annex/tmp would probably suffice).
Sponsored-by: Brett Eisenberg on Patreon
This allows getting rid of the ugly and error prone handling of
"bag of bytes" String in Remote.Helper.Encryptable.
Avoiding breakage like that dealt with by commit
9862d64bf9
And allows converting Utility.Gpg to use ByteString for IO, which is
a welcome change.
Tested the new git-annex interoperability with old, using all 3
encryption= types.
Sponsored-By: the NIH-funded NICEMAN (ReproNim TR&D3) project
giveup changed to filter out control characters. (It is too low level to
make it use StringContainingQuotedPath.)
error still does not, but it should only be used for internal errors,
where the message is not attacker-controlled.
Changed a lot of existing error to giveup when it is not strictly an
internal error.
Of course, other exceptions can still be thrown, either by code in
git-annex, or a library, that include some attacker-controlled value.
This does not guard against those.
Sponsored-by: Noam Kremen on Patreon
setEnv is not thread safe and could cause a getEnv by another thread to
segfault, or perhaps other had behavior.
Sponsored-by: Dartmouth College's Datalad project
This adds the overhead of a copy when serializing and deserializing keys.
I have not benchmarked much, but runtimes seem barely changed at all by that.
When a lot of keys are in memory, it improves memory use.
And, it prevents keys sometimes getting PINNED in memory and failing to GC,
which is a problem ByteString has sometimes. In particular, git-annex sync
from a borg special remote had that problem and this improved its memory
use by a large amount.
Sponsored-by: Shae Erisson on Patreon
Remote now contains a ParsedRemoteConfig. The parsing happens when the
Remote is constructed, rather than when individual configs are used.
This is more efficient, and it lets initremote/enableremote
reject configs that have unknown fields or unparsable values.
It also allows for improved type safety, as shown in
Remote.Helper.Encryptable where things that used to match on string
configs now match on data types.
This is a work in progress, it does not build yet.
The main risk in this conversion is forgetting to add a field to
RemoteConfigParser. That will prevent using that field with
initremote/enableremote, and will prevent remotes that already are set
up from seeing that configuration. So will need to check carefully that
every field that getRemoteConfigValue is called on has been added to
RemoteConfigParser.
(One such case I need to remember is that credPairRemoteField needs to be
included in the RemoteConfigParser.)
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 will speed up the common case where a Key is deserialized from
disk, but is then serialized to build eg, the path to the annex object.
Previously attempted in 4536c93bb2
and reverted in 96aba8eff7.
The problems mentioned in the latter commit are addressed now:
Read/Show of KeyData is backwards-compatible with Read/Show of Key from before
this change, so Types.Distribution will keep working.
The Eq instance is fixed.
Also, Key has smart constructors, avoiding needing to remember to update
the cached serialization.
Used git-annex benchmark:
find is 7% faster
whereis is 3% faster
get when all files are already present is 5% faster
Generally, the benchmarks are running 0.1 seconds faster per 2000 files,
on a ram disk in my laptop.
I found a way to avoid inheritance complicating anything outside of
Logs.Remote. It seems fine to require all inherited values to be
inherited and not set in the sameas remote's config. Since inherited
values will be used for stuff like encryption and perhaps chunking, which
control the actual content stored on the remote, it seems likely that
there will not be any reason to need them to vary between two remotes
that access the same underlying data store.
The newer version of containers is free; the minimum ghc version is
bundled with a newer version than that.
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.
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.
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.
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.
This is useful for makking a special remote that anyone with a clone of the
repo and your public keys can upload files to, but only you can decrypt the
files stored in it.
The naming is unofrtunately not consistent, but the gnupg-options
were only used for encrypting, and it's too late to change that.
It would be nice to have a third setting that is always passed to gnupg,
but ~/.gnupg/options can be used to specify such global options when really
needed.
When gpg.program is configured, it's used to get the command to run for
gpg. Useful on systems that have only a gpg2 command or want to use it
instead of the gpg command.
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.
Some remotes like External need to run store and retrieve actions in Annex,
not IO. In order to do that lift, I had to dive pretty deep into the
utilities, making Utility.Gpg and Utility.Tmp be partly converted to using
MonadIO, and Control.Monad.Catch for exception handling.
There should be no behavior changes in this commit.
This commit was sponsored by Michael Barabanov.
I'd have liked to keep these two concepts entirely separate,
but that are entagled: Storing a key in an encrypted and chunked remote
need to generate chunk keys, encrypt the keys, chunk the data, encrypt the
chunks, and send them to the remote. Similar for retrieval, etc.
So, here's an implemnetation of all of that.
The total win here is that every remote was implementing encrypted storage
and retrival, and now it can move into this single place. I expect this
to result in several hundred lines of code being removed from git-annex
eventually!
This commit was sponsored by Henrik Ahlgren.
Added new fields for chunk number, and chunk size. These will not appear
in normal keys ever, but will be used for chunked data stored on special
remotes.
This commit was sponsored by Jouni K Seppanen.
I forgot I had <$$> hidden away in Utility.Applicative.
It allows doing the same kind of currying as does >=*>
and I found using it made the code more readable for me.
(*>=> was not used)
Cipher is now a datatype
data Cipher = Cipher String | MacOnlyCipher String
which makes more precise its interpretation MAC-only vs. MAC + used to
derive a key for symmetric crypto.
With the initremote parameters "encryption=pubkey keyid=788A3F4C".
/!\ Adding or removing a key has NO effect on files that have already
been copied to the remote. Hence using keyid+= and keyid-= with such
remotes should be used with care, and make little sense unless the point
is to replace a (sub-)key by another. /!\
Also, a test case has been added to ensure that the cipher and file
contents are encrypted as specified by the chosen encryption scheme.
/!\ It is to be noted that revoking a key does NOT necessarily prevent
the owner of its private part from accessing data on the remote /!\
The only sound use of `keyid-=` is probably to replace a (sub-)key by
another, where the private part of both is owned by the same
person/entity:
git annex enableremote myremote keyid-=2512E3C7 keyid+=788A3F4C
Reference: http://git-annex.branchable.com/bugs/Using_a_revoked_GPG_key/
* Other change introduced by this patch:
New keys now need to be added with option `keyid+=`, and the scheme
specified (upon initremote only) with `encryption=`. The motivation for
this change is to open for new schemes, e.g., strict asymmetric
encryption.
git annex initremote myremote encryption=hybrid keyid=2512E3C7
git annex enableremote myremote keyid+=788A3F4C
Unless highRandomQuality=false (or --fast) is set, use Libgcypt's
'GCRY_VERY_STRONG_RANDOM' level by default for cipher generation, like
it's done for OpenPGP key generation.
On the assistant side, the random quality is left to the old (lower)
level, in order not to scare the user with an enless page load due to
the blocking PRNG waiting for IO actions.
