~wallyworld/gwacl/fix-request-eof

Viewing changes to utils.go

[r=jtv][bug=][author=allenap] Interpolate user data into URLs with correct escaping, or prevent bad data from getting interpolated.

added added

removed removed

// GNU Lesser General Public License version 3 (see the file COPYING).

package gwacl

import (

"fmt"

"net/url"

"strings"

)

// checkPathComponents checks that none of the passed components contains any

// special characters, where special means "needs percent-encoding in a URI",

// does not contain any forward slashes, and is not the string "..".

func checkPathComponents(components ...string) {

for _, component := range components {

if component != url.QueryEscape(component) {

panic(fmt.Errorf("'%s' contains URI special characters", component))

}

if component == ".." {

panic(fmt.Errorf("'..' is not allowed"))

}

// interpolateURL replaces occurrences of ___ (three underscores) with the

// components specified. Additionally, the components are percent-encoded

// (using net.url.QueryEscape) before being interpolated.

func interpolateURL(urlstring string, components ...string) string {

components_count := len(components)

replacement_count := strings.Count(urlstring, "___")

if components_count != replacement_count {

panic(fmt.Errorf("%d slot(s) but given %d replacement(s)",

replacement_count, components_count))

}

for _, component := range components {

component = url.QueryEscape(component)

urlstring = strings.Replace(urlstring, "___", component, 1)

}

return urlstring

}