A local http proxy would bypass the security configuration. So,
the security configuration has to be applied when choosing whether to
use the proxy.
While http rebinding attacks against the dns lookup of the proxy IP
address seem very unlikely, this implementation does prevent them, since
it resolves the IP address once, checks it, and then reconfigures
http-client's proxy using the resolved address.
This commit was sponsored by Ole-Morten Duesund on Patreon.
This is a clean way to add IP address restrictions to http-client, and
any library using it.
See https://github.com/snoyberg/http-client/issues/354#issuecomment-397830259
Some code from http-client and http-client-tls was copied in and
modified. Credited its author accordingly, and used the same MIT license.
The restrictions don't apply to http proxies. If using http proxies is a
problem, http-client already has a way to disable them.
SOCKS support is not included. As far as I can tell, http-client-tls
does not support SOCKS by default, and so git-annex never has.
The additional dependencies are free; git-annex already transitively
depended on them via http-conduit.
This commit was sponsored by Eric Drechsel on Patreon.
