Allow for specifying schema in "proxy" #1922

sadym-chromium · 2025-08-29T14:32:56Z

Addressing #1920.

Currently, WebDriver capabilities allow for configuring proxy by protocol. Meaning the protocol traffic can be proxied via the same protocol proxy.

Chromium can proxy traffic via different proxy protocols, and can configure which proxy to use for which protocol. In Chromium, the possible proxy schemas are http, https, socks4, socks5. Also user can configure separately proxy for HTTP, HTTPS and all other requests (SOCKS).

In order to allow for such configurations, we propose the following:

Allow for schemas (http, https, socks4, socks5) in the proxy url.
Deprecate socks in favor of other proxy configuration.

Preview | Diff

OrKoN

LGTM

whimboo · 2025-09-02T06:19:11Z

index.html

 </tr>

- <tr>
-  <td><code>socksVersion</code>


Is there a reason why you removed the socksVersion field? I thought that for socks proxies it is a mandatory field. Also if clients specify this field we would run into a backward incompatible change.

The key change is that the "socksProxy" field sets how to proxy ALL the socks connections, not only of the specific version.

WRT backward compatibility, we can figure things out if we agree on what we want to achieve.

From the Chromium perspective, the socksVersion does not make actually sense.

Removing the socks version will cause a backward incompatible change, means it will break clients using that field. We probably should fine a way to deprecate if it is really not needed. But note that when defining a socks proxy in Firefox you need to specify the version. So I don't think that we can get rid of it.

I see. I re-worked the PR so that the socksVersion can be used together with socks:// scheme.

index.html

whimboo · 2025-09-02T06:25:05Z

index.html

+  undefined.
+
+<p>A <dfn>proxy schema</dfn> is defined as being one of the following strings:
+ "<code>http</code>", "<code>https</code>", "<code>socks4</code>",


Neither socks4 nor socks5 is a valid schema as supported by Firefox. For socks proxy there is usually no schema at all when specifying the host. Does Chrome support that? Also note the other comment above regarding the backward incompatible change.

As documented here, Chrome supports proxy via HTTP, SSL, SOCKS 4 and SOCKS 5:

http://proxy:8080 uses HTTP.

https://proxy:8080 uses SSL.

socks4://proxy:8080 uses SOCKS 4.

socks5://proxy:8080 uses SOCKS 5.

socks://proxy:8080 uses SOCKS 5, as schema "socks" is alias for schema "socks5".

Neither socks4 nor socks5 is a valid schema as supported by Firefox. For socks proxy there is usually no schema at all when specifying the host. Does Chrome support that? Also note the other comment above regarding the backward incompatible change.

Does it mean that Firefox cannot proxy SOCKS 5 via SOCKS 4 and vice versa?

sadym-chromium · 2025-09-16T11:30:46Z

@whimboo WDYT?

whimboo · 2025-09-30T19:02:43Z

index.html

 </tr>

- <tr>
-  <td><code>socksVersion</code>


Removing the socks version will cause a backward incompatible change, means it will break clients using that field. We probably should fine a way to deprecate if it is really not needed. But note that when defining a socks proxy in Firefox you need to specify the version. So I don't think that we can get rid of it.

index.html

whimboo · 2025-09-30T20:08:40Z

index.html

+  <var>scheme</var> is omitted, the <var>scheme</var> is implied to be
+  "<code>http</code>". If the port is omitted and <var>scheme</var> has a


Could we at least try to figure out the right scheme (if not given) in case a default port has been set for the proxy? Using host:443 should most likely be a HTTPS proxy, or? If the port is not given, I assume that we could fallback to HTTP (HTTPS proxies still seem to be used rarely).

Should we add a note to indicate any change to the former version of the spec?

Should we add a note to indicate any change to the former version of the spec?

Do you have an idea of proper wording?

sadym-chromium · 2025-10-21T11:39:47Z

@whimboo WDYT?

sadym-chromium · 2025-11-28T10:14:25Z

@whimboo could you please take another look?

whimboo

Sorry for taking so long with my review. Inline you can find some comments so that we can continue the discussion.

whimboo · 2025-12-09T09:15:14Z

index.html

-  <td>A <a>host and optional port</a> with an <a>undefined</a> scheme.
+  <td>Defines the proxy <a>host</a> for SOCKS traffic when the
+   <a><code>proxyType</code></a> is "<code>manual</code>".
+  <td>A <a>proxy url</a>.


Shouldn't we leave the note that this URL needs to be schemeless?

Not really. This is not any different from any other proxy url and can have or have no scheme. It there is no scheme nor port, it would be considered an http, and the socks traffic will be proxied via http protocol.

whimboo · 2025-12-09T09:17:11Z

index.html

-  <td>Defines the <a>SOCKS proxy</a> version
-   when the <a><code>proxyType</code></a> is "<code>manual</code>".
+  <td>Defines the <a>SOCKS proxy</a> version when the <a>proxy url</a>'s
+   <a>proxy scheme</a> is "<code>socks</code>".


Similar to my comment above. It would be a backward compatibility breaking change when we now introduce a socks scheme.

Updated algorithm. The socksVersion is required, if any of the proxies has socks schema, or if the socksProxy don't have schema.

whimboo · 2025-12-09T09:21:26Z

index.html

+
+ <li><p>If the <var>scheme</var> is omitted and the <var>port</var> is 443,
+  the <var>scheme</var> is implied to be "<code>https</code>". Otherwise, the
+  <var>scheme</var> is implied to be "<code>http</code>".


This paragraph should only apply to HTTP or HTTPS proxies but not for a proxy URL as specified for a socks proxy.

whimboo · 2025-12-09T09:24:02Z

index.html

+
+<p>A <dfn>proxy scheme</dfn> is defined as being one of the following strings:
+ "<code>http</code>", "<code>https</code>", "<code>socks</code>",
+ "<code>socks4</code>", "<code>socks5</code>".


I still think that is a backward incompatible given that we didn't use a scheme for socks so far and I'm unsure how clients actually specify the socks proxy.

@jgraham maybe you have some additional feedback.

I updated the algorithm.

Old users omitted schema in proxy url, and expected the traffic to be proxied to the same protocol.

Now, the schema defaults to the protocol to proxy. So this the behavior for them is not changed.

However, if the user WANTS to specify schema, now they can do it.

Co-authored-by: Henrik Skupin <[email protected]>

sadym-chromium added the needs-discussion label Aug 29, 2025

sadym-chromium force-pushed the sadym/proxy branch from 8b7b4d2 to 5b447f9 Compare August 29, 2025 14:58

sadym-chromium requested a review from OrKoN August 29, 2025 15:01

sadym-chromium changed the title ~~Align "proxy" string configuration with Chromium implementation~~ Allow for "proxy" schemas Aug 29, 2025

sadym-chromium changed the title ~~Allow for "proxy" schemas~~ Allow for specifying schema in "proxy" Aug 29, 2025

sadym-chromium mentioned this pull request Aug 29, 2025

Allow for protocol schema in proxy configuration #1920

Open

sadym-chromium marked this pull request as ready for review August 29, 2025 15:33

OrKoN approved these changes Sep 1, 2025

View reviewed changes

whimboo requested changes Sep 2, 2025

View reviewed changes

sadym-chromium requested a review from whimboo September 16, 2025 11:29

whimboo requested changes Sep 30, 2025

View reviewed changes

sadym-chromium force-pushed the sadym/proxy branch from f9c0242 to 7104d77 Compare October 1, 2025 08:34

sadym-chromium requested a review from whimboo October 1, 2025 11:49

whimboo requested changes Dec 9, 2025

View reviewed changes

sadym-chromium and others added 7 commits December 9, 2025 10:42

Inline "proxy" string configuration with Chromium implementation

d64580f

restrict proxy schema

4a7ee1b

roll back socksProxy

e6a351f

schemas

73f2d59

Update index.html

3d84a8f

Co-authored-by: Henrik Skupin <[email protected]>

s/schema/scheme

1e0853d

socksVersion defines the protocol version for socks protocol

b0a959b

sadym-chromium force-pushed the sadym/proxy branch from d4a1533 to b0a959b Compare December 9, 2025 09:42

sadym-chromium added 2 commits December 9, 2025 12:38

default proxy protocol to the protocol to proxy

b22e68f

fix note

63e21ca

		<var>scheme</var> is omitted, the <var>scheme</var> is implied to be
		"<code>http</code>". If the port is omitted and <var>scheme</var> has a

Allow for specifying schema in "proxy" #1922

Are you sure you want to change the base?

Allow for specifying schema in "proxy" #1922

Uh oh!

Conversation

sadym-chromium commented Aug 29, 2025 • edited by pr-preview bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

OrKoN left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

sadym-chromium Sep 12, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

sadym-chromium commented Sep 16, 2025

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

sadym-chromium commented Oct 21, 2025

Uh oh!

sadym-chromium commented Nov 28, 2025

Uh oh!

whimboo left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

sadym-chromium commented Aug 29, 2025 •

edited by pr-preview bot

Loading

sadym-chromium Sep 12, 2025 •

edited

Loading