basic-credentials = base64-user-pass
  base64-user-pass  = <base64 encoding of user-pass,
                   except not limited to 76 char/line>
  user-pass   = userid ":" password
  userid      = *<TEXT excluding ":">
  password    = *TEXT

Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==