feat(websecure): add support for ed25519 certificates (#513)

internal/websecure/utils.go

@@ -2,6 +2,7 @@ package websecure
 
 import (
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/rand"
 	"crypto/rsa"
 	"crypto/tls"
@@ -37,11 +38,15 @@ func keyToFile(cert *tls.Certificate, filename string) error {
 		if e != nil {
 			return fmt.Errorf("failed to marshal EC private key: %v", e)
 		}
-
 		keyBlock = pem.Block{
 			Type:  "EC PRIVATE KEY",
 			Bytes: b,
 		}
+	case ed25519.PrivateKey:
+		keyBlock = pem.Block{
+			Type:  "ED25519 PRIVATE KEY",
+			Bytes: k,
+		}
 	default:
 		return fmt.Errorf("unknown private key type: %T", k)
 	}