From 89728126ccd12e452cb4ae0922f09cda469dcac8 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 12 Feb 2020 11:48:31 +0700
Subject: [PATCH] move function to create the TLS key log file to a separate
 file

---
 interop/client/main.go   | 20 ++++++++++----------
 interop/server/main.go   | 18 ++++++++----------
 interop/utils/logging.go | 19 +++++++++++++++++++
 3 files changed, 37 insertions(+), 20 deletions(-)
 create mode 100644 interop/utils/logging.go

diff --git a/interop/client/main.go b/interop/client/main.go
index b7858ea97..90c748d04 100644
--- a/interop/client/main.go
+++ b/interop/client/main.go
@@ -11,10 +11,12 @@ import (
 	"os"
 	"strings"
 
+	"golang.org/x/sync/errgroup"
+
 	"github.com/lucas-clemente/quic-go/http3"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/interop/http09"
-	"golang.org/x/sync/errgroup"
+	"github.com/lucas-clemente/quic-go/interop/utils"
 )
 
 var errUnsupported = errors.New("unsupported test case")
@@ -30,15 +32,13 @@ func main() {
 	defer logFile.Close()
 	log.SetOutput(logFile)
 
-	var keyLog io.Writer
-	if filename := os.Getenv("SSLKEYLOGFILE"); len(filename) > 0 {
-		f, err := os.Create(filename)
-		if err != nil {
-			fmt.Printf("Could not create key log file: %s\n", err.Error())
-			os.Exit(1)
-		}
-		defer f.Close()
-		keyLog = f
+	keyLog, err := utils.GetSSLKeyLog()
+	if err != nil {
+		fmt.Printf("Could not create key log: %s\n", err.Error())
+		os.Exit(1)
+	}
+	if keyLog != nil {
+		defer keyLog.Close()
 	}
 
 	tlsConf = &tls.Config{
diff --git a/interop/server/main.go b/interop/server/main.go
index c31866765..bdaee82d6 100644
--- a/interop/server/main.go
+++ b/interop/server/main.go
@@ -3,7 +3,6 @@ package main
 import (
 	"crypto/tls"
 	"fmt"
-	"io"
 	"log"
 	"net"
 	"net/http"
@@ -13,6 +12,7 @@ import (
 	"github.com/lucas-clemente/quic-go/http3"
 	"github.com/lucas-clemente/quic-go/internal/testdata"
 	"github.com/lucas-clemente/quic-go/interop/http09"
+	"github.com/lucas-clemente/quic-go/interop/utils"
 )
 
 var tlsConf *tls.Config
@@ -26,15 +26,13 @@ func main() {
 	defer logFile.Close()
 	log.SetOutput(logFile)
 
-	var keyLog io.Writer
-	if filename := os.Getenv("SSLKEYLOGFILE"); len(filename) > 0 {
-		f, err := os.Create(filename)
-		if err != nil {
-			fmt.Printf("Could not create key log file: %s\n", err.Error())
-			os.Exit(1)
-		}
-		defer f.Close()
-		keyLog = f
+	keyLog, err := utils.GetSSLKeyLog()
+	if err != nil {
+		fmt.Printf("Could not create key log: %s\n", err.Error())
+		os.Exit(1)
+	}
+	if keyLog != nil {
+		defer keyLog.Close()
 	}
 
 	testcase := os.Getenv("TESTCASE")
diff --git a/interop/utils/logging.go b/interop/utils/logging.go
new file mode 100644
index 000000000..11e4e897e
--- /dev/null
+++ b/interop/utils/logging.go
@@ -0,0 +1,19 @@
+package utils
+
+import (
+	"io"
+	"os"
+)
+
+// GetSSLKeyLog creates a file for the TLS key log
+func GetSSLKeyLog() (io.WriteCloser, error) {
+	filename := os.Getenv("SSLKEYLOGFILE")
+	if len(filename) == 0 {
+		return nil, nil
+	}
+	f, err := os.Create(filename)
+	if err != nil {
+		return nil, err
+	}
+	return f, nil
+}