add base64 host key param

cmd/sshpiperd/daemon.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"encoding/base64"
 	"fmt"
 	"net"
 	"os"
@@ -27,29 +28,46 @@ func newDaemon(ctx *cli.Context) (*daemon, error) {
 	config := &ssh.PiperConfig{}
 	config.SetDefaults()
 
-	privateKeys, err := filepath.Glob(ctx.String("server-key"))
-	if err != nil {
-		return nil, err
-	}
+	keybase64 := ctx.String("server-key-data")
+	if keybase64 != "" {
+		log.Infof("parsing host key in base64 params")
 
-	if len(privateKeys) == 0 {
-		return nil, fmt.Errorf("no server key found")
-	}
-
-	log.Infof("found host keys %v", privateKeys)
-	for _, privateKey := range privateKeys {
-		log.Infof("loading host key %v", privateKey)
-		privateBytes, err := os.ReadFile(privateKey)
+		privateBytes, err := base64.StdEncoding.DecodeString(keybase64)
 		if err != nil {
 			return nil, err
 		}
 
-		private, err := ssh.ParsePrivateKey(privateBytes)
+		private, err := ssh.ParsePrivateKey([]byte(privateBytes))
 		if err != nil {
 			return nil, err
 		}
 
 		config.AddHostKey(private)
+	} else {
+		privateKeyFiles, err := filepath.Glob(ctx.String("server-key"))
+		if err != nil {
+			return nil, err
+		}
+
+		if len(privateKeyFiles) == 0 {
+			return nil, fmt.Errorf("no server key found")
+		}
+
+		log.Infof("found host keys %v", privateKeyFiles)
+		for _, privateKey := range privateKeyFiles {
+			log.Infof("loading host key %v", privateKey)
+			privateBytes, err := os.ReadFile(privateKey)
+			if err != nil {
+				return nil, err
+			}
+
+			private, err := ssh.ParsePrivateKey(privateBytes)
+			if err != nil {
+				return nil, err
+			}
+
+			config.AddHostKey(private)
+		}
 	}
 
 	lis, err := net.Listen("tcp", net.JoinHostPort(ctx.String("address"), ctx.String("port")))

cmd/sshpiperd/main.go

@@ -97,6 +97,11 @@ func main() {
 				Value:   "/etc/ssh/ssh_host_ed25519_key",
 				EnvVars: []string{"SSHPIPERD_SERVER_KEY"},
 			},
+			&cli.StringFlag{
+				Name:    "server-key-data",
+				Usage:   "server key in base64 format, server-key will be ignored if set",
+				EnvVars: []string{"SSHPIPERD_SERVER_KEY_DATA"},
+			},
 			&cli.DurationFlag{
 				Name:    "login-grace-time",
 				Value:   30 * time.Second,

e2e/fixed_test.go

@@ -1,7 +1,9 @@
 package e2e_test
 
 import (
+	"encoding/base64"
 	"fmt"
+	"strings"
 	"testing"
 	"time"
 
@@ -58,3 +60,35 @@ func TestFixed(t *testing.T) {
 
 	checkSharedFileContent(t, targetfie, randtext)
 }
+
+func TestHostkeyParam(t *testing.T) {
+	_, piperport := nextAvailablePiperAddress()
+	keyparam := base64.StdEncoding.EncodeToString([]byte(testprivatekey))
+
+	piper, _, _, err := runCmd("/sshpiperd/sshpiperd",
+		"-p",
+		piperport,
+		"--server-key-data",
+		keyparam,
+		"/sshpiperd/plugins/fixed",
+		"--target",
+		"host-password:2222",
+	)
+
+	if err != nil {
+		t.Errorf("failed to run sshpiperd: %v", err)
+	}
+
+	defer killCmd(piper)
+
+	b, err := runAndGetStdout(
+		"ssh-keyscan",
+		"-p",
+		piperport,
+		"127.0.0.1",
+	)
+
+	if !strings.Contains(string(b), testpublickey) {
+		t.Errorf("failed to get correct hostkey, %v", err)
+	}
+}

e2e/main_test.go

@@ -29,6 +29,8 @@ AAAEDcQgdh2z2r/6blq0ziJ1l6s6IAX8C+9QHfAH931cHNO9RGTH325rDUp12tplwukHmR
 -----END OPENSSH PRIVATE KEY-----
 `
 
+const testpublickey = `ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAINRGTH325rDUp12tplwukHmR8ytbC9TPZ886gCstynP1`
+
 const waitTimeout = time.Second * 10
 
 func waitForEndpointReady(addr string) {