Standardize random string generation on stdnse.generate_random_string

scripts/http-userdir-enum.nse

@@ -146,25 +146,3 @@ function init()
   stdnse.debug1("Testing %d usernames.", #usernames)
   return nil
 end
-
-
-
----
--- Uses openssl.rand_pseudo_bytes (if available, os.time() if not) and base64.enc
--- to produce a randomish string of at least 11 alphanumeric chars.
--- @return String
-
-function randomstring()
-  local rnd, s, l, _
-  local status, openssl = pcall(require, "openssl")
-  if status then
-    rnd = openssl.rand_pseudo_bytes
-  end
-  s = rnd and rnd(8) or tostring( os.time() )
-  -- increase the length of the string by 0 to 7 chars
-  _, l = bin.unpack(">C", s, 8) -- eighth byte should be safe for os.time() too
-  s = l%8 > 0 and s .. s:sub(1,l%8) or s
-  -- base 64 encode and replace any non alphanum chars (with 'n' for nmap!)
-  s = base64.enc(s):sub(1,-2):gsub("%W", "n")
-  return s
-end