From 82afd9492a7d8b7dee4e92e90a70e5fe30b6681e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mika=C3=ABl=20Cluseau?= <mikael.cluseau@gmail.com>
Date: Sun, 17 Dec 2023 15:33:56 +0100
Subject: [PATCH] ssh: load more host key formats than rsa

---
 ssh.go | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/ssh.go b/ssh.go
index b053c89..cb9386b 100644
--- a/ssh.go
+++ b/ssh.go
@@ -23,18 +23,28 @@ func startSSH(cfg *config.Config) {
 		PublicKeyCallback: sshCheckPubkey,
 	}
 
-	pkBytes, err := os.ReadFile("/id_rsa") // TODO configurable
-	if err != nil {
-		fatalf("ssh: failed to load private key: %v", err)
+	hostKeyLoaded := false
+
+	for _, format := range []string{"rsa", "dsa", "ecdsa", "ed25519"} {
+		pkBytes, err := os.ReadFile("/id_" + format)
+		if err != nil {
+			log.Printf("ssh : failed to load %s host key: %v", format, err)
+			continue
+		}
+
+		pk, err := ssh.ParsePrivateKey(pkBytes)
+		if err != nil {
+			log.Printf("ssh: failed to parse %s host key: %v", format, err)
+			continue
+		}
+
+		sshConfig.AddHostKey(pk)
 	}
 
-	pk, err := ssh.ParsePrivateKey(pkBytes)
-	if err != nil {
-		fatalf("ssh: failed to parse private key: %v", err)
+	if !hostKeyLoaded {
+		fatalf("ssh: failed to load any host key")
 	}
 
-	sshConfig.AddHostKey(pk)
-
 	sshBind := ":22" // TODO configurable
 	listener, err := net.Listen("tcp", sshBind)
 	if err != nil {