docs/diploma
diff thesis/tex/1-Introduction.tex @ 160:d8ad54f11e88
added text segment about the main goal of masqmail
author | meillo@marmaro.de |
---|---|
date | Wed, 17 Dec 2008 18:47:32 +0100 |
parents | 0d097f4300ce |
children | aab8499c9f2f |
line diff
1.1 --- a/thesis/tex/1-Introduction.tex Wed Dec 17 15:12:42 2008 +0100 1.2 +++ b/thesis/tex/1-Introduction.tex Wed Dec 17 18:47:32 2008 +0100 1.3 @@ -25,7 +25,8 @@ 1.4 The program's new homepage \citeweb{masqmail:homepage} provides further information about this \MTA. 1.5 1.6 1.7 -\subsubsection{Target field} 1.8 +\subsubsection*{Target field} 1.9 + 1.10 Its original author, Oliver \person{Kurth}, sees \masqmail\ so: 1.11 \begin{quote} 1.12 MasqMail is a mail server designed for hosts that do not have a permanent internet connection eg. a home network or a single host at home. It has special support for connections to different ISPs. It replaces sendmail or other MTAs such as qmail or exim. 1.13 @@ -45,7 +46,7 @@ 1.14 1.15 1.16 1.17 -\subsubsection{Typical usage} 1.18 +\subsubsection*{Typical usage} 1.19 This section describes situations that make senseful use of \masqmail. 1.20 1.21 A home network consisting of some workstations without a server. The network is connected to the internet by dial-up or broadband. Going online is initiated by computers inside the local net. \NAME{IP} addresses change at least once every day. 1.22 @@ -66,7 +67,42 @@ 1.23 --- 1.24 1.25 1.26 -\subsubsection{What makes it special} 1.27 + 1.28 + 1.29 + 1.30 +\subsubsection*{\masqmail's main goal} 1.31 + 1.32 +\masqmail\ does have similar requirements, by being a \sendmail\ replacement, which is a basic goal of the project. The main difference is that \masqmail\ is intended to be used on workstations and in small networks, but \sendmail, \qmail, and \postfix\ are designed to run on large mail servers to handle masses of email. The author of \masqmail, \person{Kurth}, in contrast, warns on the old project's website \citeweb{masqmail:homepage2} about using it to accept connections from the Internet, because of the risk to be an open relay: 1.33 +\begin{quote} 1.34 +MasqMail is not designed to run on a host with a permanent internet connection. It does not have the ability to check for spam mail and it will relay everything from everywhere to everywhere. Use another mail server such as exim for permanent connections. 1.35 +\end{quote} 1.36 +Even if some relay control will be added, ``is not designed to'' is a clear indicator for being careful. Issues like high memory consumption, low performance, and denial-of-service attacks---things not regarded by design---may cause serious problems. 1.37 + 1.38 +Here shows a misfit off: On the one hand does \masqmail\ want to be a \sendmail\ replacement. But on the other hand, is it not designed to be used like \sendmail. If \masqmail\ is inteded to replace other \MTA{}s, then one may replace another one with it. Hence it must be secure enough. It either needs the security features or must drop the unsecure funtionality. The second option, however, leads to being \emph{no} replacement for other \MTA{}s. It is a valid decision to not be a replacement for \sendmail\ or thelike, but this is a design decision---the change of a primary goal. 1.39 + 1.40 +If \masqmail\ should be an \MTA\ to replace others, a switch to a better suited architecture that provides good security and extendability by design, seems required. But if \masqmail\ is wanted to cover some special jobs, not to replace common \MTA{}s, then its architecture depends on the special requirements of the specific job; \MTA\ architectures, like discussed by \person{Hafiz}, may be inadequate. 1.41 + 1.42 + 1.43 +\subsubsection*{Full featured or stripped down} 1.44 + 1.45 +What future is to choose for \masqmail---one to be a full featured \MTA, or one to be a stipped down \MTA\ for special jobs? 1.46 + 1.47 +The critical point to discuss upon is surely the listening on a port to accepte messages from outside via \NAME{SMTP} (herafter also refered to as the \NAME{SMTP}-in channel). This feature is required for an \MTA\ to be a \name{smart host}, to relay mail. But running as deamon and listening on a port requires much more security effort, because the program is put in direct contact with attackers and other bad guys. 1.48 + 1.49 +\MTA{}s without \SMTP-in channels can not receive mail from arbitrary outside hosts. They are only invoked by local users. This lowers the security need a lot---however, security is a general goal and still required, but on a lower level. Unfortunately, as they do not receive mail anymore (except by local submission), they are just better \name{forwarders} that are able to send mail directly to the destination. 1.50 + 1.51 +This is not what \masqmail\ was intended to be. Programs that cover this purpose are available; one is \name{msmtp}. 1.52 + 1.53 +\masqmail\ shall be a complete \mta. It shall be able to replace ones like \sendmail. 1.54 + 1.55 + 1.56 + 1.57 + 1.58 + 1.59 + 1.60 + 1.61 + 1.62 +\subsubsection*{What makes it special} 1.63 1.64 As main advantage, \masqmail\ makes it easy to set up an \MTA\ on workstations or notebooks without the need to do complex configuration or to be an mail server expert. 1.65