diff --git a/functions b/functions
index 2c113fe..4f40a85 100644
--- a/functions
+++ b/functions
@@ -16,15 +16,12 @@ generate_private_key () {
 # Firmar el archivo usando la llave privada.
 #
 # Uso: sign_file archivo.json
-# Devuelve: archivo.json.sign
+# Devuelve: La firma
 sign_file () {
   local _file="$1"
 
   test ! -f "$_file" && return 1
-  if test -f "$_file.sig" ; then
-    echo "$_file.sig"
-    return 0
-  fi
+  test -f "$_file.sig" || ssh-keygen -Y sign -f ~/.ssh/id_ed25519 -n file "$_file" 2>&1 >/dev/null
 
-  LC_ALL=C ssh-keygen -Y sign -f ~/.ssh/id_ed25519 -n file "$_file" 2>&1| grep Write | cut -d " " -f 4
+  cat "${_file}.sig" | grep -v SIGNATURE | tr -d "\n"
 }