1 files changed, 9 insertions, 3 deletions

diff --git a/src/daemon/https/tls/gnutls_str.c b/src/daemon/https/tls/gnutls_str.c
index 22f949d6..d5e95366 100644
--- a/src/daemon/https/tls/gnutls_str.c
+++ b/src/daemon/https/tls/gnutls_str.c
@@ -236,12 +236,18 @@ mhd_gtls_string_append_printf (mhd_gtls_string * dest, const char *fmt, ...)
   char *str;
 
   va_start (args, fmt);
-  len = vasprintf (&str, fmt, args);
+  len = vsnprintf (NULL, 0, fmt, args);
   va_end (args);
-
-  if (len < 0 || !str)
+  if (len < 0)
+    return -1;
+  str = malloc(len + 1);
+  if (! str)
     return -1;
 
+  va_start (args, fmt);
+  len = vsprintf (str, fmt, args);
+  va_end (args);
+
   len = mhd_gtls_string_append_str (dest, str);
 
   free (str);