Using http_proxy environment variable in Templates with qubes Updates Proxy

[farrilis]

Using Qubes 4.0 in Whonix 14 template


When using curl, the -x (or --proxy) parameter accepts the address
(127.0.0.1:8082) that redirects to Qubes Updates proxy over RPC, and
returns what you would expect.

But with wget (which I think is a better choice than curl), setting the
http_proxy environment variable is needed (according to 'man wget' and
web resources)


Using the following commands:

'export use_proxy=on'
'export http_proxy=http://127.0.0.1:8082'
'wget https://gitlab.com/repo/filename'

produces this output:

" Resolving gitlab.com (gitlab.com)... failed: Non-recoverable failure
in name resolution.
wget: unable to resolve host address 'gitlab.com' "


Then try a domain name that does not exist:

" Connecting to 127.0.0.1:8082... connected.
Proxy request sent, awaiting response... 500 Unable to connect
2019-03-10 15:17:23 ERROR 500: Unable to connect. "


What could the problem be? curl can use 127.0.0.1:8082, why not wget?

[Matthew Finkel]

wget leaks dns - by this I mean wget tries resolving the domain name locally and then uses the result from that as the destination of the proxied connection. If the DNS resolution query fails, then wget gives you that error. Curl, in comparison, (correctly) asks the proxy to handle the entire connection including the hostname resolution.

[unman]

This isnt the case in buster, where (from my testing) wget honours the
proxy variable and does not attempt local dns lookups.