net/http: fix authentication info leakage in Referer header (potential security risk)

http.Client calls URL.String() to fill in the Referer header, which may
contain authentication info. This patch removes authentication info from
the Referer header without introducing any API changes.

A new test for net/http is also provided.

This is the polished version of Alberto García Hierro's
https://golang.org/cl/9766046/

It should handle https Referer right.

Fixes #8417

LGTM=bradfitz
R=golang-codereviews, gobot, bradfitz, mikioh.mikioh
CC=golang-codereviews
https://golang.org/cl/151430043

1 files changed, 5 insertions, 0 deletions

diff --git a/src/net/http/export_test.go b/src/net/http/export_test.go
index a6980b5389..87b6c0773a 100644
--- a/src/net/http/export_test.go
+++ b/src/net/http/export_test.go
@@ -9,6 +9,7 @@ package http
 
 import (
 	"net"
+	"net/url"
 	"time"
 )
 
@@ -92,6 +93,10 @@ func ResetCachedEnvironment() {
 
 var DefaultUserAgent = defaultUserAgent
 
+func ExportRefererForURL(lastReq, newReq *url.URL) string {
+	return refererForURL(lastReq, newReq)
+}
+
 // SetPendingDialHooks sets the hooks that run before and after handling
 // pending dials.
 func SetPendingDialHooks(before, after func()) {