net/url: parseQuery() does not check for space in url

[TidesOfMemories]

What version of Go are you using (go version)?

$ go version
go version go1.14.2 linux/amd64

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/eepgnao/.cache/go-build"
GOENV="/home/eepgnao/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/eepgnao/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/eepgnao/.linuxbrew/Cellar/go/1.14.2_1/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/eepgnao/.linuxbrew/Cellar/go/1.14.2_1/libexec/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc-7"
CXX="g++-7"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build885884852=/tmp/go-build -gno-record-gcc-switches"

What did you do?

What did you expect to see?

An err value is returned when the query URL contains space character

What did you see instead?

space character is parsed into the value of the dict

[davecheney]

Please provide a runnable sample to demonstrate what you did. Thank you

[TidesOfMemories]

@davecheney

package main

import (
	"net/url"
	"fmt"
)

func main() {
	oriqueryForm0, err0 := url.ParseQuery(`http://192.168.240.36:3000/nnrf-disc/v1/nf-instances?service-names=  &requester-nf-instance-fqdn=seliiu`)
	if err0 == nil {
	    fmt.Printf("service names = %s", oriqueryForm0["service-names"])
	}
}

//The code above should not print anything out because of the space char behind "service-names="

[davecheney]

Thank you for your sample code, why do you believe that the space should terminate the URL? Do you have an example where a browser or client send this URL?

[TidesOfMemories]

@davecheney
According to RFC 3986, space characters should not be allowed in URLs.
In most cases, browsers will translate space characters to %20 or terminate the request.
In some applications(such as bare metal embedded systems) where clients are not using a browser and there is no validation check for the URL, then the server will not be able to detect the error in the URL if the incoming request URL is used as an argument for parseQuery
I used a simple HTTP2 client & server demo code I found on the internet and verified the behavior. Please let me know if you are interested in seeing the code.

[networkimprov]

cc @bradfitz

[davecheney]

@pp5311006 i think this is a question of where the url comes from. It is not possible for a URL with a space in it to be transmitted by HTTP. The space could be present if the url was stored in a database or file or read via input. This sounds like an input validation problem, but equally given the problems this could cause maybe ParseQuery could be stricter about the input it accepts.

[TidesOfMemories]

@davecheney
You are right. I would love to see ParseQuery function having a stricter input validation check.
Currently we are trying to prevent this problem by doing extra validation check, it would be nice to have it in ParseQuery by default.

[seankhliao]

I don't think we can do this, in #33596 we have an example of users expecting spaces to work.