Fix some hash debugging
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 8efd57e..53f12f4 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -2040,7 +2040,8 @@
 
         }
 
-        SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen );
+        SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen != 0 ? hashlen :
+                (unsigned int) ( md_info_from_type( md_alg ) )->size );
 
         /*
          * Make the signature