Files
hadrian/proxychain/responsemodifiers/modify_incoming_scripts_with_regex.go
2023-12-09 08:08:36 -06:00

54 lines
1.4 KiB
Go

package responsemodifiers
import (
"bytes"
"io"
"regexp"
"strings"
"github.com/everywall/ladder/proxychain"
)
// ModifyIncomingScriptsWithRegex modifies all incoming javascript (application/javascript and inline <script> in text/html) using a regex match and replacement.
func ModifyIncomingScriptsWithRegex(matchRegex string, replacement string) proxychain.ResponseModification {
return func(chain *proxychain.ProxyChain) error {
path := chain.Request.URL.Path
ct := chain.Response.Header.Get("content-type")
isJavascript := strings.HasSuffix(path, ".js") || ct == "text/javascript" || ct == "application/javascript"
isHTML := strings.HasSuffix(chain.Request.URL.Path, ".html") || ct == "text/html"
switch {
case isJavascript:
rBody, err := modifyResponse(chain.Response.Body, matchRegex, replacement)
if err != nil {
return err
}
chain.Response.Body = rBody
case isHTML:
default:
return nil
}
return nil
}
}
func modifyResponse(body io.ReadCloser, matchRegex, replacement string) (io.ReadCloser, error) {
content, err := io.ReadAll(body)
if err != nil {
return nil, err
}
re, err := regexp.Compile(matchRegex)
if err != nil {
return nil, err
}
err = body.Close()
if err != nil {
return body, err
}
modifiedContent := re.ReplaceAll(content, []byte(replacement))
return io.NopCloser(bytes.NewReader(modifiedContent)), nil
}