net/http: remove test-only private key from production binaries

The net/http/internal package contains a PEM-encoded private key used in
tests. This key is initialized at init time, which prevents it from
being stripped by the linker in non-test binaries.

Move the certificate and key to a new net/http/internal/testcert
package to ensure it is only included in binaries that reference it.

Fixes #46677.

Change-Id: Ie98bda529169314cc791063e7ce4d99ef99113c8
Reviewed-on: https://go-review.googlesource.com/c/go/+/326771
Trust: Damien Neil <dneil@google.com>
Run-TryBot: Damien Neil <dneil@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

src/go/build/deps_test.go

@@ -440,7 +440,8 @@ var depsRules = `
 	# HTTP, King of Dependencies.
 
 	FMT
-	< golang.org/x/net/http2/hpack, net/http/internal, net/http/internal/ascii;
+	< golang.org/x/net/http2/hpack
+	< net/http/internal, net/http/internal/ascii, net/http/internal/testcert;
 
 	FMT, NET, container/list, encoding/binary, log
 	< golang.org/x/text/transform
@@ -459,6 +460,7 @@ var depsRules = `
 	golang.org/x/net/http2/hpack,
 	net/http/internal,
 	net/http/internal/ascii,
+	net/http/internal/testcert,
 	net/http/httptrace,
 	mime/multipart,
 	log

src/net/http/httptest/server.go

@@ -14,7 +14,7 @@ import (
 	"log"
 	"net"
 	"net/http"
-	"net/http/internal"
+	"net/http/internal/testcert"
 	"os"
 	"strings"
 	"sync"
@@ -144,7 +144,7 @@ func (s *Server) StartTLS() {
 	if s.client == nil {
 		s.client = &http.Client{Transport: &http.Transport{}}
 	}
-	cert, err := tls.X509KeyPair(internal.LocalhostCert, internal.LocalhostKey)
+	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
 	if err != nil {
 		panic(fmt.Sprintf("httptest: NewTLSServer: %v", err))
 	}

src/net/http/internal/testcert/testcert.go

@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package internal
+// Package testcert contains a test-only localhost certificate.
+package testcert
 
 import "strings"
 
@@ -25,7 +26,7 @@ h1fIw3cSS2OolhloGw/XM6RWPWtPAlGykKLciQrBru5NAPvCMsb/I1DAceTiotQM
 fblo6RBxUQ==
 -----END CERTIFICATE-----`)
 
-// LocalhostKey is the private key for localhostCert.
+// LocalhostKey is the private key for LocalhostCert.
 var LocalhostKey = []byte(testingKey(`-----BEGIN RSA TESTING KEY-----
 MIICXgIBAAKBgQDuLnQAI3mDgey3VBzWnB2L39JUU4txjeVE6myuDqkM/uGlfjb9
 SjY1bIw4iA5sBBZzHi3z0h1YV8QPuxEbi4nW91IJm2gsvvZhIrCHS3l6afab4pZB

src/net/http/serve_test.go

@@ -25,6 +25,7 @@ import (
 	"net/http/httptest"
 	"net/http/httputil"
 	"net/http/internal"
+	"net/http/internal/testcert"
 	"net/url"
 	"os"
 	"os/exec"
@@ -1475,7 +1476,7 @@ func TestServeTLS(t *testing.T) {
 	defer afterTest(t)
 	defer SetTestHookServerServe(nil)
 
-	cert, err := tls.X509KeyPair(internal.LocalhostCert, internal.LocalhostKey)
+	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1599,7 +1600,7 @@ func TestAutomaticHTTP2_Serve_WithTLSConfig(t *testing.T) {
 }
 
 func TestAutomaticHTTP2_ListenAndServe(t *testing.T) {
-	cert, err := tls.X509KeyPair(internal.LocalhostCert, internal.LocalhostKey)
+	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1609,7 +1610,7 @@ func TestAutomaticHTTP2_ListenAndServe(t *testing.T) {
 }
 
 func TestAutomaticHTTP2_ListenAndServe_GetCertificate(t *testing.T) {
-	cert, err := tls.X509KeyPair(internal.LocalhostCert, internal.LocalhostKey)
+	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
 	if err != nil {
 		t.Fatal(err)
 	}

src/net/http/transport_internal_test.go

@@ -12,7 +12,7 @@ import (
 	"errors"
 	"io"
 	"net"
-	"net/http/internal"
+	"net/http/internal/testcert"
 	"strings"
 	"testing"
 )
@@ -191,7 +191,7 @@ func (f roundTripFunc) RoundTrip(r *Request) (*Response, error) {
 
 // Issue 25009
 func TestTransportBodyAltRewind(t *testing.T) {
-	cert, err := tls.X509KeyPair(internal.LocalhostCert, internal.LocalhostKey)
+	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
 	if err != nil {
 		t.Fatal(err)
 	}

src/net/http/transport_test.go

@@ -30,7 +30,7 @@ import (
 	"net/http/httptest"
 	"net/http/httptrace"
 	"net/http/httputil"
-	"net/http/internal"
+	"net/http/internal/testcert"
 	"net/textproto"
 	"net/url"
 	"os"
@@ -4299,7 +4299,7 @@ func TestTransportReuseConnEmptyResponseBody(t *testing.T) {
 
 // Issue 13839
 func TestNoCrashReturningTransportAltConn(t *testing.T) {
-	cert, err := tls.X509KeyPair(internal.LocalhostCert, internal.LocalhostKey)
+	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
 	if err != nil {
 		t.Fatal(err)
 	}