Remove semi-colon as query string separator

[FroMage]

Version

4.5.27

Context

As reported in Quarkus at quarkusio/quarkus#50685 it seems Vert.x Web treats semicolons as separators in HTTP query strings, which is not supposed to be the case according to the various HTTP specs.

The only mention of semicolon in specs as separator I can find is on https://en.wikipedia.org/wiki/Query_string:

This convention is a W3C recommendation.[3] In the recommendations of 1999, W3C recommended that all web servers support semicolon separators in addition to ampersand separators[6] to allow application/x-www-form-urlencoded query strings in URLs within HTML documents without having to entity escape ampersands. Since 2014, W3C recommends to use only ampersand as query separator.[7]

In practice, I've never seen them being used as separators in query strings ever. Mozilla agrees with this.

Apparently, Netty supports the option of not treating them as separators in QueryStringDecoder: netty/netty@7d6d953

We should probably make this into a configurable option, that could default to whatever you want for Vert.x, and we'll default to "do not treat semicolons as separator" in Quarkus at https://github.com/vert-x3/vertx-web/blob/master/vertx-web/src/main/java/io/vertx/ext/web/impl/RoutingContextImpl.java#L447

Steps to reproduce

No response

Do you have a reproducer?

No response

[vietj]

isn't this a problem in vertx-core instead ?

[FroMage]

Why? The option is used in https://github.com/vert-x3/vertx-web/blob/master/vertx-web/src/main/java/io/vertx/ext/web/impl/RoutingContextImpl.java#L447 so that's Vert.x web, no?

[vietj]

Actually we got actually this covered in vertx-core which has a similar issue and a solution to change the parsing delimiter was added and vertx-web has the same issue (because of re-routing it needs to be duplicated). So I could port the same feature to RoutingContext : e.g. make the router configurable at creation time that configures the default behavior concerning the handling of semi colon

[FroMage]

That would work, I guess.

[vietj]

I think we could change the default behavior if that's globally better in Vert.x 6

[vietj]

Vert.x 5.1 will get a new configuration object for query parameters decoder in vertx-core for HttpServerRequest, this object will be reused on the router. If that is needed for 4.5.x, we can make this possible on the Router but only for the specific option as this is in the new HTTP config layer of 5.1

For 5.1, it will look like

    router.queryParamDecoderConfig(new QueryParamDecoderConfig().setUseSemicolonAsDelimiter(false));

[vietj]

Actually I made it for 5.1 as it will reuse the HTTP server query param configuration, without needing to reconfigure the router.

[vietj]

I think we could port that to 4.x as just a semi colon parameter on the HTTP server that would be the default instead of a full config object, this semi colon parameter would be also in 5.1 and set the corresponding property on the query param decoder config of the http server config. WDYT @FroMage ?