1 files changed, 38 insertions, 3 deletions
diff --git a/doc/guide.tex b/doc/guide.tex
index 44e8a3af8..9463d57aa 100644
--- a/doc/guide.tex
+++ b/doc/guide.tex
@@ -1187,8 +1187,7 @@ for user authentication. The syntax is:
 The following authentication methods are supported by \ejabberd{}:
 \begin{itemize}
 \item internal (default) --- See section~\ref{internalauth}.
-\item external --- There are \footahref{http://www.ejabberd.im/extauth}{some
- example authentication scripts}.
+\item external --- See section~\ref{extauth}.
 \item ldap --- See section~\ref{ldap}.
 \item odbc --- See section~\ref{mysql}, \ref{pgsql},
   \ref{mssql} and \ref{odbc}.
@@ -1196,7 +1195,7 @@ The following authentication methods are supported by \ejabberd{}:
 \item pam --- See section~\ref{pam}.
 \end{itemize}
 
-Account creation is only supported by internal and odbc methods.
+Account creation is only supported by internal, external and odbc methods.
 
 \makesubsubsection{internalauth}{Internal}
 \ind{internal authentication}\ind{Mnesia}
@@ -1218,6 +1217,42 @@ Examples:
 \end{verbatim}
 \end{itemize}
 
+\makesubsubsection{extauth}{External Script}
+\ind{external authentication}
+
+In this authentication method, when \ejabberd{} starts,
+it start a script, and calls it to perform authentication tasks.
+
+The server administrator can write the external authentication script
+in any language.
+The details on the interface between ejabberd and the script are described
+in the \term{ejabberd Developers Guide}.
+There are also \footahref{http://www.ejabberd.im/extauth}{several example authentication scripts}.
+
+These are the specific options:
+\begin{description}
+  \titem{\{extauth\_program, PathToScript\}} 
+  Indicate in this option the full path to the external authentication script.
+  The script must be executable by ejabberd.
+
+  \titem{\{extauth\_cache, false|CacheTimeInteger\}} 
+  The value \term{false} disables the caching feature, this is the default.
+  The integer \term{0} (zero) enables caching for statistics, but doesn't use that cached information to authenticate users.
+  If another integer value is set, caching is enabled both for statistics and for authentication:
+  the CacheTimeInteger indicates the number of seconds that ejabberd can reuse
+  the authentication information since the user last disconnected,
+  to verify again the user authentication without querying again the extauth script.
+  Note: caching should not be enabled in a host if internal auth is also enabled.
+  If caching is enabled, \term{mod\_last} or \term{mod\_last\_odbc} must be enabled also in that vhost.
+\end{description}
+
+This example sets external authentication, the extauth script, and enables caching for 10 minutes:
+\begin{verbatim}
+{auth_method, [external]}.
+{extauth_program, "/etc/ejabberd/JabberAuth.class.php"}.
+{extauth_cache, 600}.
+\end{verbatim}
+
 \makesubsubsection{saslanonymous}{SASL Anonymous and Anonymous Login}
 \ind{sasl anonymous}\ind{anonymous login}