5f0f063a7a documented it as being
configured automatically, but the code never did that. Rather than try
to hard-code whatever urls amazon uses for its buckets, it seems better
to ask the user to find the url and set it.
addurl: When security configuration prevents downloads with youtube-dl,
still check if the url is one that it supports, and fail downloading it,
instead of downloading the raw web page.
Leveraged the existing verification code by making it also check the
retrievalSecurityPolicy.
Also, prevented getViaTmp from running the download action at all when the
retrievalSecurityPolicy is going to prevent verifying and so storing it.
Added annex.security.allow-unverified-downloads. A per-remote version
would be nice to have too, but would need more plumbing, so KISS.
(Bill the Cat reference not too over the top I hope. The point is to
make this something the user reads the documentation for before using.)
A few calls to verifyKeyContent and getViaTmp, that don't
involve downloads from remotes, have RetrievalAllKeysSecure hard-coded.
It was also hard-coded for P2P.Annex and Command.RecvKey,
to match the values of the corresponding remotes.
A few things use retrieveKeyFile/retrieveKeyFileCheap without going
through getViaTmp.
* Command.Fsck when downloading content from a remote to verify it.
That content does not get into the annex, so this is ok.
* Command.AddUrl when using a remote to download an url; this is new
content being added, so this is ok.
This commit was sponsored by Fernando Jimenez on Patreon.
They're no worse than http certianly. And, the backport of these
security fixes has to deal with wget, which supports http https and ftp
and has no way to turn off individual schemes, so this will make that
easier.
Security fix!
* git-annex will refuse to download content from http servers on
localhost, or any private IP addresses, to prevent accidental
exposure of internal data. This can be overridden with the
annex.security.allowed-http-addresses setting.
* Since curl's interface does not have a way to prevent it from accessing
localhost or private IP addresses, curl defaults to not being used
for url downloads, even if annex.web-options enabled it before.
Only when annex.security.allowed-http-addresses=all will curl be used.
Since S3 and WebDav use the Manager, the same policies apply to them too.
youtube-dl is not handled yet, and a http proxy configuration can bypass
these checks too. Those cases are still TBD.
This commit was sponsored by Jeff Goeke-Smith on Patreon.
Security fix! Allowing any schemes, particularly file: and
possibly others like scp: allowed file exfiltration by anyone who had
write access to the git repository, since they could add an annexed file
using such an url, or using an url that redirected to such an url,
and wait for the victim to get it into their repository and send them a copy.
* Added annex.security.allowed-url-schemes setting, which defaults
to only allowing http and https URLs. Note especially that file:/
is no longer enabled by default.
* Removed annex.web-download-command, since its interface does not allow
supporting annex.security.allowed-url-schemes across redirects.
If you used this setting, you may want to instead use annex.web-options
to pass options to curl.
With annex.web-download-command removed, nearly all url accesses in
git-annex are made via Utility.Url via http-client or curl. http-client
only supports http and https, so no problem there.
(Disabling one and not the other is not implemented.)
Used curl --proto to limit the allowed url schemes.
Note that this will cause git annex fsck --from web to mark files using
a disallowed url scheme as not being present in the web. That seems
acceptable; fsck --from web also does that when a web server is not available.
youtube-dl already disabled file: itself (probably for similar
reasons). The scheme check was also added to youtube-dl urls for
completeness, although that check won't catch any redirects it might
follow. But youtube-dl goes off and does its own thing with other
protocols anyway, so that's fine.
Special remotes that support other domain-specific url schemes are not
affected by this change. In the bittorrent remote, aria2c can still
download magnet: links. The download of the .torrent file is
otherwise now limited by annex.security.allowed-url-schemes.
This does not address any external special remotes that might download
an url themselves. Current thinking is all external special remotes will
need to be audited for this problem, although many of them will use
http libraries that only support http and not curl's menagarie.
The related problem of accessing private localhost and LAN urls is not
addressed by this commit.
This commit was sponsored by Brett Eisenberg on Patreon.
