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If I try to start Chromium or any Chromium-based browser with:

[...] --proxy-server="socks5h://blablabla"

Then it fails to load any page. However, it works if I do:

[...] --proxy-server="socks5://blablabla"

But SOCKS5H and SOCKS5 are slightly different in an important way. the "H" one doesn't leak your privacy by bypassing the proxy for DNS lookups, but this is not supported in Chromium?

The proxies I am trying are otherwise working (such as via cURL) and are indeed SOCKS5H.

I find not a word about this online, "surprisingly".

The error given is something like this:

This site can’t be reached The webpage at https://ifconfig.co/json might be temporarily down or it may have moved permanently to a new web address. ERR_NO_SUPPORTED_PROXIES

Marcio Kraimer
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1 Answers1

6

This convention originated in curl : When socks5 is used the domain name is resolved locally and the resolved IP is passed to the proxy server. This is usually undesirable, since it leaks DNS requests, defeating some of the privacy of using proxy, etc. socks5h caused curl to pass domain name to the SOCKS server verbatim and let the server do the resolving.

Nowadays, most client programs do not resolve locally the domain name, so the socks5h protocol has fallen into disuse. For such clients, socks5h is the same as socks5, or in other words all socks5 are actually socks5h.

Evidently, Firefox is one such client.

harrymc
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