Attachment 73405 Details for Bug 106425 – file.diff

[patch] file.diff

file.diff (text/plain), 74.77 KB, created by Niclas Zeising on 2006-12-06 21:50:03 UTC

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Creator: Niclas Zeising

Created: 2006-12-06 21:50:03 UTC

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>--- doc/en_US.ISO8859-1/books/handbook/security/chapter.sgml.orig	2006-11-12 11:13:08.000000000 +0100
>+++ doc/en_US.ISO8859-1/books/handbook/security/chapter.sgml	2006-11-12 19:10:20.000000000 +0100
>@@ -66,17 +66,20 @@
>       </listitem>
> 
>       <listitem>
>-	<para>How to configure IPsec and create a <acronym>VPN</acronym> between
>-	&os;/&windows; machines.</para>
>+	<para>How to configure IPsec and create a 
>+	  <acronym role="Virual Private Network">VPN</acronym> between
>+	  &os;/&windows; machines. </para>
>       </listitem>
>      
>       <listitem>
>-	<para>How to configure and use <application>OpenSSH</application>, &os;'s <acronym>SSH</acronym>
>-	  implementation.</para>
>+	<para>How to configure and use <application>OpenSSH</application>
>+	  , &os;'s <acronym role="Secure Shell">SSH</acronym> implementation.
>+	  </para>
>       </listitem>
> 
>       <listitem>
>-	<para>What file system <acronym>ACL</acronym>s are and how to use them.</para>
>+	<para>What file system <acronym role="Access Control Lists">ACL</acronym>s
>+	  are and how to use them.</para>
>       </listitem>
> 
>       <listitem>
>@@ -128,15 +131,14 @@
>       inter-networked, security becomes an even bigger issue.</para>
> 
>     <para>System security also pertains to dealing with various forms of
>-      attack, including attacks that attempt to crash, or otherwise make a
>+      attacks, including attacks that attempt to crash, or otherwise make a
>       system unusable, but do not attempt to compromise the
>       <username>root</username> account (<quote>break root</quote>).
>-      Security concerns
>-      can be split up into several categories:</para>
>+      Security concerns can be split up into several categories:</para>
> 
>     <orderedlist>
>       <listitem>
>-	<para>Denial of service attacks.</para>
>+	<para>Denial of service (DoS) attacks.</para>
>       </listitem>
> 
>       <listitem>
>@@ -168,14 +170,14 @@
>     <indexterm><primary>Denial of Service (DoS)</primary></indexterm>
> 
>     <para>A denial of service attack is an action that deprives the
>-      machine of needed resources.  Typically, DoS attacks are
>-      brute-force mechanisms that attempt to crash or otherwise make a
>+      machine of needed resources.  Typically, <acronym>DoS</acronym> attacks
>+      are brute-force mechanisms that attempt to crash or otherwise make a
>       machine unusable by overwhelming its servers or network stack.  Some
>-      DoS attacks try to take advantage of bugs in the networking
>-      stack to crash a machine with a single packet.  The latter can only
>-      be fixed by applying a bug fix to the kernel.  Attacks on servers
>-      can often be fixed by properly specifying options to limit the load
>-      the servers incur on the system under adverse conditions.
>+      <acronym>DoS</acronym> attacks try to take advantage of bugs in the
>+      networking stack to crash a machine with a single packet.  The latter
>+      can only be fixed by applying a bug fix to the kernel.  Attacks on
>+      servers can often be fixed by properly specifying options to limit the
>+      load the servers incur on the system under adverse conditions.
>       Brute-force network attacks are harder to deal with.  A
>       spoofed-packet attack, for example, is nearly impossible to stop,
>       short of cutting your system off from the Internet.  It may not be
>@@ -187,8 +189,8 @@
>       <secondary>account compromises</secondary>
>     </indexterm>
> 
>-    <para>A user account compromise is even more common than a DoS
>-      attack.  Many sysadmins still run standard 
>+    <para>A user account compromise is even more common than a
>+      <acronym>DoS</acronym> attack.  Many sysadmins still run standard 
>       <application>telnetd</application>, <application>rlogind</application>,
>       <application>rshd</application>,
>       and <application>ftpd</application> servers on their machines.
>@@ -226,7 +228,7 @@
>       a suid-root program that allows the attacker to break
>       <username>root</username> once he has broken into a user's account.
>       If an attacker has found a way to break <username>root</username>
>-      on a machine, the attacker may not have a need
>+      on a machine, the attacker may have the need
>       to install a backdoor.  Many of the <username>root</username> holes
>       found and closed to date involve a considerable amount of work
>       by the attacker to cleanup after himself, so most attackers install
>@@ -294,9 +296,8 @@
>        <application>bold</application> text to refer to an
>        application, and a <command>monospaced</command> font to refer
>        to specific commands.  Protocols will use a normal font.  This
>-       typographical distinction is useful for instances such as ssh,
>-       since it is
>-       a protocol as well as command.</para>
>+       typographical distinction is useful for instances such as SSH,
>+       since it is a protocol as well as command.</para>
>     </note>
> 
>     <para>The sections that follow will cover the methods of securing your
>@@ -348,8 +349,8 @@
> 	<groupname>wheel</groupname> group are allowed to
> 	<command>su</command> to <username>root</username>.
> 	You should never give staff
>-	members native <groupname>wheel</groupname> access by putting them in the
>-	<groupname>wheel</groupname> group in their password entry.  Staff
>+	members native <groupname>wheel</groupname> access by putting them in
>+	the <groupname>wheel</groupname> group in their password entry.  Staff
> 	accounts should be placed in a <groupname>staff</groupname> group, and
> 	then added to the <groupname>wheel</groupname> group via the
> 	<filename>/etc/group</filename> file.  Only those staff members
>@@ -565,7 +566,7 @@
> 	have sufficient control, then you may win out and be able to secure
> 	the user accounts properly.  If not, you simply have to be more
> 	vigilant in your monitoring of those accounts.  Use of
>-	ssh and Kerberos for user accounts is
>+	SSH and Kerberos for user accounts is
> 	more problematic, due to the extra administration and technical
> 	support required, but still a very good solution compared to a
> 	encrypted password file.</para>
>@@ -575,7 +576,7 @@
>       <title>Securing the Password File</title>
> 
>       <para>The only sure fire way is to star out as many
>-	passwords as you can and use ssh or
>+	passwords as you can and use SSH or
> 	Kerberos for access to those accounts.  Even though the encrypted
> 	password file (<filename>/etc/spwd.db</filename>) can only be read
> 	by <username>root</username>, it may be possible for an intruder
>@@ -663,9 +664,9 @@
> 	have to give the limited-access box significant access to the
> 	other machines in the business, usually either by doing a
> 	read-only NFS export of the other machines to the limited-access
>-	box, or by setting up ssh key-pairs to
>-	allow the limited-access box to ssh to
>-	the other machines.  Except for its network traffic, NFS is the
>+	box, or by setting up SSH key-pairs to
>+	allow the limited-access box to use <application>ssh</application> to
>+	access the other machines.  Except for its network traffic, NFS is the
> 	least visible method &mdash; allowing you to monitor the
> 	file systems on each client box virtually undetected.  If your
> 	limited-access server is connected to the client boxes through a
>@@ -674,8 +675,7 @@
> 	hub, or through several layers of routing, the NFS method may be
> 	too insecure (network-wise) and using
> 	ssh may be the better choice even with
>-	the audit-trail tracks that ssh
>-	lays.</para>
>+	the audit-trail tracks that SSH lays.</para>
> 
>       <para>Once you have given a limited-access box at least read access to the
> 	client systems it is supposed to monitor, you must write scripts
>@@ -694,13 +694,13 @@
> 
>       <para>When using ssh rather than NFS,
> 	writing the security script is much more difficult.   You
>-	essentially have to <command>scp</command> the scripts to the client 
>+	essentially have to <command>scp</command> the scripts to the client
> 	box in order to
> 	run them, making them visible, and for safety you also need to
> 	<command>scp</command> the binaries (such as find) that those
> 	scripts use.  The <application>ssh</application> client on the
> 	client box may already be compromised.  All in all, using
>-	ssh may be necessary when running over
>+	SSH may be necessary when running over
> 	insecure links, but it is also a lot harder to deal with.</para>
> 
>       <para>A good security script will also check for changes to user and
>@@ -753,8 +753,9 @@
>       <title>Denial of Service Attacks</title>
>       <indexterm><primary>Denial of Service (DoS)</primary></indexterm>
> 
>-      <para>This section covers Denial of Service attacks.  A DoS attack
>-	is typically a packet attack.  While there is not much you can do
>+      <para>This section covers Denial of Service attacks.  A
>+        <acronym role="Denial of Service">DoS</acronym> attack is typically
>+	a packet attack.  While there is not much you can do
> 	about modern spoofed packet attacks that saturate your network,
> 	you can generally limit the damage by ensuring that the attacks
> 	cannot take down your servers by:</para>
>@@ -774,16 +775,16 @@
> 	</listitem>
>       </orderedlist>
> 
>-      <para>A common DoS attack scenario is attacking a forking server and
>-	making it spawning so many child processes that the host system
>-	eventually runs out of memory, file descriptors, etc. and then
>-	grinds to a halt.  <application>inetd</application> 
>-	(see &man.inetd.8;) has several
>+      <para>A common <acronym>DoS</acronym> attack scenario is attacking a
>+        forking server and making it spawning so many child processes that the
>+	host system eventually runs out of memory, file descriptors, etc. and
>+	then grinds to a halt.  The <application>inetd</application>
>+	application (see &man.inetd.8;) has several
> 	options to limit this sort of attack.  It should be noted that
> 	while it is possible to prevent a machine from going down, it is
> 	not generally possible to prevent a service from being disrupted
> 	by the attack.  Read the <application>inetd</application> manual
>-	page carefully and pay
>+	page &man.inetd.8; carefully and pay
> 	specific attention to the <option>-c</option>, <option>-C</option>,
> 	and <option>-R</option> options.  Note that spoofed-IP attacks
> 	will circumvent the <option>-C</option> option to 
>@@ -822,8 +823,8 @@
>       <para>It is a very good idea to protect internal services from
> 	external access by firewalling them off at your border routers.
> 	The idea here is to prevent saturation attacks from outside your
>-	LAN, not so much to protect internal services from network-based
>-	<username>root</username> compromise.
>+	<acronym>LAN</acronym>, not so much to protect internal services from
>+	network-based <username>root</username> compromise.
> 	Always configure an exclusive firewall, i.e.,
> 	<quote>firewall everything <emphasis>except</emphasis> ports A, B,
> 	C, D, and M-Z</quote>.  This way you can firewall off all of your
>@@ -840,7 +841,7 @@
> 	without compromising your low ports.  Also take note that &os;
> 	allows you to control the range of port numbers used for dynamic
> 	binding, via the various <varname>net.inet.ip.portrange</varname>
>-	<command>sysctl</command>'s (<command>sysctl -a | fgrep
>+	<command>sysctl</command>s (<command>sysctl -a | fgrep
> 	portrange</command>), which can also ease the complexity of your
> 	firewall's configuration.  For example, you might use a normal
> 	first/last range of 4000 to 5000, and a hiport range of 49152 to
>@@ -848,9 +849,9 @@
> 	(except for certain specific Internet-accessible ports, of
> 	course).</para>
> 
>-      <para>Another common DoS attack is called a springboard attack
>-	&mdash; to attack a server in a manner that causes the server to
>-	generate responses which overloads the server, the local
>+      <para>Another common <acronym>DoS</acronym> attack is called a 
>+        springboard attack &mdash; to attack a server in a manner that causes
>+	the server to generate responses which overloads the server, the local
> 	network, or some other machine.  The most common attack of this
> 	nature is the <emphasis>ICMP ping broadcast attack</emphasis>.
> 	The attacker spoofs ping packets sent to your LAN's broadcast
>@@ -862,13 +863,14 @@
> 	trick on several dozen broadcast addresses over several dozen
> 	different networks at once.  Broadcast attacks of over a hundred
> 	and twenty megabits have been measured.  A second common
>-	springboard attack is against the ICMP error reporting system.
>-	By constructing packets that generate ICMP error responses, an
>-	attacker can saturate a server's incoming network and cause the
>-	server to saturate its outgoing network with ICMP responses.  This
>-	type of attack can also crash the server by running it out of
>-	memory, especially if the server cannot drain the ICMP responses
>-	it generates fast enough.
>+	springboard attack is against the
>+	<acronym role="Internet Control Message Protocol">ICMP</acronym> error
>+	reporting system. By constructing packets that generate
>+	<acronym>ICMP</acronym> error responses, an attacker can saturate a
>+	server's incoming network and cause the server to saturate its outgoing
>+	network with ICMP responses. This type of attack can also crash the
>+	server by running it out of memory, especially if the server cannot
>+	drain the ICMP responses it generates fast enough.
> 	Use the <application>sysctl</application>
> 	variable <literal>net.inet.icmp.icmplim</literal> to limit these attacks.
> 	The last major class of springboard
>@@ -889,12 +891,12 @@
> 	route cache.  Refer to the <varname>net.inet.ip.rtexpire</varname>,
> 	<varname>rtminexpire</varname>, and <varname>rtmaxcache</varname>
> 	<command>sysctl</command> parameters.  A spoofed packet attack
>-	that uses a random source IP will cause the kernel to generate a
>-	temporary cached route in the route table, viewable with
>+	that uses a random source IP address will cause the kernel to generate
>+	a temporary cached route in the route table, viewable with
> 	<command>netstat -rna | fgrep W3</command>.  These routes
> 	typically timeout in 1600 seconds or so.  If the kernel detects
> 	that the cached route table has gotten too big it will dynamically
>-	reduce the <varname>rtexpire</varname> but will never decrease it 
>+	reduce the <varname>rtexpire</varname> but will never decrease it
> 	to less than <varname>rtminexpire</varname>.  There are two 
> 	problems:</para>
> 	
>@@ -925,17 +927,16 @@
>       <indexterm><primary>KerberosIV</primary></indexterm>
> 
>       <para>There are a few issues with both Kerberos and
>-	ssh that need to be addressed if
>+	SSH that need to be addressed if
> 	you intend to use them.  Kerberos 5 is an excellent
> 	authentication protocol, but there are bugs in the kerberized
> 	<application>telnet</application> and
> 	<application>rlogin</application> applications that make them
> 	unsuitable for dealing with binary streams.  Also, by default
> 	Kerberos does not encrypt a session unless you use the
>-	<option>-x</option> option.  <application>ssh</application>
>-	encrypts everything by default.</para>
>+	<option>-x</option> option.  SSH encrypts everything by default.</para>
> 
>-      <para>Ssh works quite well in every
>+      <para>SSH works quite well in every
> 	respect except that it forwards encryption keys by default.  What
> 	this means is that if you have a secure workstation holding keys
> 	that give you access to the rest of the system, and you
>@@ -948,17 +949,16 @@
> 	access to any other machine that your keys unlock.</para>
> 
>       <para>We recommend that you use ssh in
>-	combination with Kerberos whenever possible for staff logins.
>-	<application>Ssh</application> can be compiled with Kerberos
>-	support.  This reduces your reliance on potentially exposed
>-	ssh keys while at the same time
>-	protecting passwords via Kerberos.  Ssh
>-	keys should only be used for automated tasks from secure machines
>+	combination with Kerberos whenever possible for staff logins.  The
>+	<application>ssh</application> client and server can be compiled with
>+	Kerberos support.  This reduces your reliance on potentially exposed
>+	SSH keys while at the same time protecting passwords via Kerberos.
>+	SSH keys should only be used for automated tasks from secure machines
> 	(something that Kerberos is unsuited to do).  We also recommend that
> 	you either turn off key-forwarding in the
>-	ssh configuration, or that you make use
>+	<application>ssh</application> configuration, or that you make use
> 	of the <literal>from=IP/DOMAIN</literal> option that
>-	ssh allows in its
>+	<application>ssh</application> allows in its
> 	<filename>authorized_keys</filename> file to make the key only
> 	usable to entities logging in from specific machines.</para>
>     </sect2>
>@@ -1000,48 +1000,52 @@
>       space of possible passwords.</para>
> 
>     <para>Unfortunately the only secure way to encrypt passwords when
>-      &unix; came into being was based on DES, the Data Encryption
>-      Standard.  This was not such a problem for users resident in
>-      the US, but since the source code for DES could not be exported
>-      outside the US, &os; had to find a way to both comply with 
>+      &unix; came into being was based on
>+      <acronym role="Data Encryption Standard">DES</acronym>, the Data
>+      Encryption Standard.  This was not such a problem for users resident in
>+      the US, but since the source code for <acronym>DES</acronym> could not be 
>+      exported outside the US, &os; had to find a way to both comply with 
>       US law and retain compatibility with all the other &unix;
>-      variants that still used DES.</para>
>+      variants that still used <acronym>DES</acronym>.</para>
> 
>     <para>The solution was to divide up the encryption libraries 
>-      so that US users could install the DES libraries and use
>-      DES but international users still had an encryption method
>-      that could be exported abroad.  This is how &os; came to
>-      use MD5 as its default encryption method.  MD5 is believed to
>-      be more secure than DES, so installing DES is offered primarily
>-      for compatibility reasons.</para>
>+      so that US users could install the <acronym>DES</acronym> libraries and
>+      use <acronym>DES</acronym> but international users still had an
>+      encryption method that could be exported abroad.  This is how &os; came
>+      to use <acronym role="Message Digest 5">MD5</acronym> as its default
>+      encryption method.  <acronym>MD5</acronym> is believed to be more secure
>+      than <acronym>DES</acronym>, so installing <acronym>DES</acronym> is
>+      offered primarily for compatibility reasons.</para>
> 
>     <sect2>
>       <title>Recognizing Your Crypt Mechanism</title>
> 
>-      <para>Currently the library supports DES, MD5 and Blowfish hash
>-	functions.  By default &os; uses MD5 to encrypt
>+      <para>Currently the library supports <acronym>DES</acronym>,
>+      <acronym>MD5</acronym> and Blowfish hash
>+	functions.  By default &os; uses <acronym>MD5</acronym> to encrypt
> 	passwords.</para>
> 
>       <para>It is pretty easy to identify which encryption method 
> 	&os; is set up to use.  Examining the encrypted passwords in
> 	the <filename>/etc/master.passwd</filename> file is one way.
>-	Passwords encrypted with the MD5 hash are longer than those
>-	encrypted with the DES hash and also begin with the characters
>-	<literal>&dollar;1&dollar;</literal>.  Passwords starting with
>-	<literal>&dollar;2a&dollar;</literal> are encrypted with the
>-	Blowfish hash function.  DES password strings do not
>-	have any particular identifying characteristics, but they are
>-	shorter than MD5 passwords, and are coded in a 64-character
>-	alphabet which does not include the <literal>&dollar;</literal>
>-	character, so a relatively short string which does not begin with
>-	a dollar sign is very likely a DES password.</para>
>+	Passwords encrypted with the <acronym>MD5</acronym> hash are longer
>+	than those encrypted with the <acronym>DES</acronym> hash and also
>+	begin with the characters <literal>&dollar;1&dollar;</literal>.  
>+	Passwords starting with <literal>&dollar;2a&dollar;</literal> are
>+	encrypted with the Blowfish hash function.  <acronym>DES</acronym>
>+	password strings do not have any particular identifying characteristics,
>+	but they are shorter than <acronym>MD5</acronym> passwords, and are
>+	coded in a 64-character alphabet which does not include the
>+	<literal>&dollar;</literal> character, so a relatively short string
>+	which does not begin with a dollar sign is very likely a
>+	<acronym>DES</acronym> password.</para>
> 
>       <para>The password format used for new passwords is controlled
> 	by the <literal>passwd_format</literal> login capability in
> 	<filename>/etc/login.conf</filename>, which takes values of
> 	<literal>des</literal>, <literal>md5</literal> or
> 	<literal>blf</literal>.  See the &man.login.conf.5; manual page
>-	for more information about login capabilities.</para>
>+	for more information on login capabilities.</para>
> 
>     </sect2>
>   </sect1>
>@@ -1054,16 +1058,17 @@
>       <secondary>one-time passwords</secondary>
>     </indexterm>
> 
>-    <para>By default, &os; includes support for OPIE (One-time Passwords
>-      In Everything), which uses the MD5 hash by default.</para>
>+    <para>By default, &os; includes support for
>+      <acronym role="One-Time Passwords In Everything">OPIE</acronym>
>+      (One-time Passwords In Everything), which uses the
>+      <acronym>MD5</acronym> hash by default.</para>
> 
>     <para>There are three different sorts of passwords which we will discuss
>       below.  The first is your usual &unix; style or
>       Kerberos password; we will call this a <quote>&unix; password</quote>.
>-      The second sort is the one-time password which is generated by the OPIE
>-      &man.opiekey.1; program and accepted by the
>-      &man.opiepasswd.1; program
>-      and the login prompt; we will
>+      The second sort is the one-time password which is generated by the 
>+      <acronym>OPIE</acronym> &man.opiekey.1; program and accepted by the
>+      &man.opiepasswd.1; program and the login prompt; we will
>       call this a <quote>one-time password</quote>.  The final sort of
>       password is the secret password which you give to the
>       <command>opiekey</command> program (and
>@@ -1075,32 +1080,33 @@
> 
>     <para>The secret password does not have anything to do with your &unix;
>       password; they can be the same but this is not recommended.
>-      OPIE secret passwords are not limited to 8 characters like old
>-      &unix; passwords<footnote><para>Under &os; the standard login
>+      <acronym>OPIE</acronym> secret passwords are not limited to 8 characters
>+      like old &unix; passwords<footnote><para>Under &os; the standard login
>       password may be up to 128 characters in length.</para></footnote>,
>       they can be as long as you like.  Passwords of six or
>       seven word long phrases are fairly common.  For the most part, the
>-      OPIE system operates completely independently of the &unix;
>-      password system.</para>
>+      <acronym>OPIE</acronym> system operates completely independently of the
>+      &unix; password system.</para>
> 
>     <para>Besides the password, there are two other pieces of data that
>-      are important to OPIE.  One is what is known as the
>+      are important to <acronym>OPIE</acronym>.  One is what is known as the
>       <quote>seed</quote> or <quote>key</quote>, consisting of two letters
>       and five digits.  The other is what is called the <quote>iteration
>-      count</quote>, a number between 1 and 100.  OPIE creates the
>-      one-time password by concatenating the seed and the secret password,
>-      then applying the MD5 hash as many times as specified by the
>-      iteration count and turning the result into six short English words.
>-      These six English words are your one-time password.  The
>-      authentication system (primarily PAM) keeps
>-      track of the last one-time password used, and the user is
>+      count</quote>, a number between 1 and 100.  <acronym>OPIE</acronym> 
>+      creates the one-time password by concatenating the seed and the secret 
>+      password, then applying the <acronym>MD5</acronym> hash as many times as
>+      specified by the iteration count and turning the result into six short 
>+      English words. These six English words are your one-time password.  The
>+      authentication system (primarily 
>+      <acronym role="Pluggable Authentication Modules">PAM</acronym>)
>+      keeps track of the last one-time password used, and the user is
>       authenticated if the hash of the user-provided password is equal to
>       the previous password.  Because a one-way hash is used it is
>       impossible to generate future one-time passwords if a successfully
>       used password is captured; the iteration count is decremented after
>       each successful login to keep the user and the login program in
>-      sync.  When the iteration count gets down to 1, OPIE must be
>-      reinitialized.</para>
>+      sync.  When the iteration count gets down to 1, <acronym>OPIE</acronym>
>+      must be reinitialized.</para>
> 
>     <para>There are a few programs involved in each system
>       which we will discuss below.  The
>@@ -1108,7 +1114,7 @@
>       count, a seed, and a secret password, and generates a one-time
>       password or a consecutive list of one-time passwords.  The
>       <command>opiepasswd</command>
>-      program is used to initialize OPIE,
>+      program is used to initialize <acronym>OPIE</acronym>,
>       and to change passwords, iteration counts, or seeds; it
>       takes either a secret passphrase, or an iteration count,
>       seed, and a one-time password.  The
>@@ -1133,8 +1139,8 @@
> 
>     <sect2>
>       <title>Secure Connection Initialization</title>
>-      <para>To initialize OPIE for the first time, execute the
>-        <command>opiepasswd</command> command:</para>
>+      <para>To initialize <acronym>OPIE</acronym> for the first time, execute
>+        the <command>opiepasswd</command> command:</para>
> 
>       <screen>&prompt.user; <userinput>opiepasswd -c</userinput>
> [grimreaper] ~ $ opiepasswd -f -c
>@@ -1210,7 +1216,7 @@
>     <sect2>
>       <title>Generating a Single One-time Password</title>
> 
>-      <para>Once you have initialized OPIE and login, you will be 
>+      <para>Once you have initialized OPIE and login, you will be
> 	presented with a prompt like this:</para>
> 
> <screen>&prompt.user; <userinput>telnet example.com</userinput>
>@@ -1224,8 +1230,8 @@
> otp-md5 498 gr4269 ext
> Password: </screen>
> 
>-      <para>As a side note, the OPIE prompts have a useful feature
>-	(not shown here): if you press <keycap>Return</keycap>
>+      <para>As a side note, the <acronym>OPIE</acronym> prompts have a useful
>+        feature (not shown here): if you press <keycap>Return</keycap>
> 	at the password prompt, the
> 	prompter will turn echo on, so you can see what you are
> 	typing.  This can be extremely useful if you are attempting to
>@@ -1290,8 +1296,8 @@
>     <sect2>
>       <title>Restricting Use of &unix; Passwords</title>
> 
>-      <para>OPIE can restrict the use of &unix; passwords based on the IP
>-	address of a login session.  The relevant file
>+      <para><acronym>OPIE</acronym> can restrict the use of &unix; passwords
>+        based on the IP address of a login session.  The relevant file
> 	is <filename>/etc/opieaccess</filename>, which is present by default.
> 	Please check &man.opieaccess.5;
> 	for more information on this file and which security considerations
>@@ -1327,7 +1333,8 @@
>     <title>TCP Wrappers</title>
> 
>     <para>Anyone familiar with &man.inetd.8; has probably heard
>-      of <acronym>TCP</acronym> Wrappers at some point.  But few
>+      of <acronym role="Transport Control Protocol">TCP</acronym>
>+      Wrappers at some point.  But few
>       individuals seem to fully comprehend its usefulness in a
>       network environment.  It seems that everyone wants to
>       install a firewall to handle network connections.  While a
>@@ -1591,8 +1598,9 @@
>         during the era of restrictive export controls on cryptographic
>         code from the USA.</para>
> 
>-      <para>Alternatively, the MIT implementation of Kerberos is
>-        available from the Ports Collection as
>+      <para>Alternatively, the 
>+        <acronym role="Massachusetts Insitute of Technology">MIT</acronym>
>+	implementation of Kerberos is available from the Ports Collection as
>         <filename role="package">security/krb5</filename>.</para>
>     </sect2>
> 
>@@ -1889,7 +1897,7 @@
> Apr 30 11:23:22  Apr 30 19:23:22  krbtgt.EXAMPLE.COM@EXAMPLE.COM</screen>
> 
>       <para>Now try changing the password using &man.passwd.1; to
>-	check if the <application>kpasswd</application> daemon can get 
>+	check if the <application>kpasswd</application> daemon can get
> 	authorization to the Kerberos database:</para>
> 
>       <screen>&prompt.user; <userinput>passwd</userinput>
>@@ -2133,7 +2141,7 @@
> 	programs that implement the program
> 	(<application>Kerberos</application> telnet, for example).  The
> 	current version of the protocol is version 5, described in
>-	<acronym>RFC</acronym>&nbsp;1510.</para>
>+	<acronym role="Request For Comments">RFC</acronym>&nbsp;1510.</para>
> 
>       <para>Several free implementations of this protocol are available,
> 	covering a wide range of operating systems.  The Massachusetts
>@@ -2168,7 +2176,8 @@
> 	<secondary>Key Distribution Center</secondary>
>       </indexterm>
> 
>-      <para>The Key Distribution Center (<acronym>KDC</acronym>) is the
>+      <para>The Key Distribution Center 
>+        <acronym role="Key Distribution Center">KDC</acronym>) is the
> 	centralized authentication service that
> 	<application>Kerberos</application> provides &mdash; it is the
> 	computer that issues <application>Kerberos</application> tickets.
>@@ -2580,8 +2589,9 @@
> 	      immediately upon running <command>kinit</command> &mdash;
> 	      even before you type your password!  The explanation is
> 	      that the <application>Kerberos</application> server freely
>-	      transmits a <acronym>TGT</acronym> (Ticket Granting
>-	      Ticket) to any unauthorized request;  however, every
>+	      transmits a
>+	      <acronym role="Ticket Granting Ticket">TGT</acronym> (Ticket
>+	      Granting Ticket) to any unauthorized request;  however, every
> 	      <acronym>TGT</acronym> is encrypted in a key derived from
> 	      the user's password.  Therefore, when a user types their
> 	      password it is not being sent to the <acronym>KDC</acronym>,
>@@ -2726,7 +2736,7 @@
> 	</sect3>
> 
> 	<sect3>
>-	  <title>The KDC is a single point of failure</title>
>+	  <title>The <acronym>KDC</acronym> is a single point of failure</title>
> 
> 	  <para>By design, the <acronym>KDC</acronym> must be as secure as
> 	    the master password database is contained on it.  The
>@@ -2783,7 +2793,8 @@
> 	  <listitem>
> 	  <para><ulink
> 	    url="http://www.faqs.org/faqs/Kerberos-faq/general/preamble.html">
>-	    The <application>Kerberos</application> FAQ</ulink></para>
>+	    The <application>Kerberos</application> <acronym>FAQ</acronym>
>+	    </ulink></para>
> 	</listitem>
> 
> 	<listitem>
>@@ -2792,9 +2803,10 @@
> 	</listitem>
> 
> 	<listitem>
>-	  <para><ulink url="http://www.ietf.org/rfc/rfc1510.txt?number=1510">RFC 1510,
>-	    The <application>Kerberos</application> Network Authentication Service
>-	    (V5)</ulink></para>
>+	  <para><ulink
>+	  url="http://www.ietf.org/rfc/rfc1510.txt?number=1510">
>+	    <acronym>RFC</acronym> 1510, The <application>Kerberos</application>
>+	    Network Authentication Service (V5)</ulink></para>
> 	</listitem>
> 
> 	<listitem>
>@@ -2850,9 +2862,12 @@
>     </note>
> 
>     <para>The version of <application>OpenSSL</application> included
>-      in &os; supports Secure Sockets Layer v2/v3 (SSLv2/SSLv3),
>-      Transport Layer Security v1 (TLSv1) network security protocols
>-      and can be used as a general cryptographic library.</para>
>+      in &os; supports Secure Sockets Layer v2/v3 (
>+      <acronym role="Secure Sockets Layer">SSL</acronym>v2/
>+      <acronym>SSL</acronym>v3), Transport Layer Security v1 
>+      (<acronym role="Transport Layer Security">TLS</acronym>v1) network 
>+      security protocols and can be used as a general cryptographic library.
>+      </para>
> 
>     <note>
>       <para>While <application>OpenSSL</application> supports the
>@@ -2869,8 +2884,9 @@
>       that the credentials of the company or individual are valid
>       and not fraudulent.  If the certificate in question has
>       not been verified by one of the several <quote>Certificate Authorities</quote>,
>-      or <acronym>CA</acronym>s, a warning is usually produced.  A
>-      Certificate Authority is a company, such as <ulink url="http://www.verisign.com">VeriSign</ulink>, which will
>+      or <acronym role="Certificate Authorities">CA</acronym>s, a warning is
>+      usually produced.  A Certificate Authority is a company, such as
>+      <ulink url="http://www.verisign.com">VeriSign</ulink>, which will
>       sign certificates in order to validate credentials of individuals
>       or companies.  This process has a cost associated with it and
>       is definitely not a requirement for using certificates; however,
>@@ -2961,9 +2977,9 @@
> 
>       <para>So what can these files do?  A good use would be to
> 	encrypt connections to the <application>Sendmail</application>
>-	<acronym>MTA</acronym>.  This would dissolve the use of clear
>-	text authentication for users who send mail via the local
>-	<acronym>MTA</acronym>.</para>
>+	<acronym role="Mail Transport Agent">MTA</acronym>.  This would
>+	dissolve the use of clear text authentication for users who send
>+	mail via the local <acronym>MTA</acronym>.</para>
> 
>       <note>
> 	<para>This is not the best use in the world as some
>@@ -3047,7 +3063,8 @@
>     </indexterm>
> 
>     <title>VPN over IPsec</title>
>-    <para>Creating a VPN between two networks, separated by the
>+    <para>Creating a <acronym role="Virtual Private Network">VPN</acronym>
>+      between two networks, separated by the
>       Internet, using FreeBSD gateways.</para>
>  
>     <sect2>
>@@ -3067,30 +3084,33 @@
>       <title>Understanding IPsec</title>
> 
>       <para>This section will guide you through the process of setting
>-	up IPsec, and to use it in an environment which consists of
>+	up <acronym role="IP Security">IPsec</acronym>, and to use it in an
>+	environment which consists of
> 	FreeBSD and <application>&microsoft.windows; 2000/XP</application>
> 	machines, to make them communicate securely.  In order to set up
>-	IPsec, it is necessary that you are familiar with the concepts
>-	of building a custom kernel (see
>+	<acronym>IPsec</acronym>, it is necessary that you are familiar with
>+	the concepts of building a custom kernel (see
> 	<xref linkend="kernelconfig">).</para>
>     
>       <para><emphasis>IPsec</emphasis> is a protocol which sits on top
>-	of the Internet Protocol (IP) layer.  It allows two or more
>-	hosts to communicate in a secure manner (hence the name).  The
>-	FreeBSD IPsec <quote>network stack</quote> is based on the
>-	<ulink url="http://www.kame.net/">KAME</ulink> implementation,
>-	which has support for both protocol families, IPv4 and
>-	IPv6.</para>
>+	of the Internet Protocol 
>+	(<acronym role="Internet Protocol"IP</acronym>) layer.  It allows two
>+	or more hosts to communicate in a secure manner (hence the name).  The
>+	FreeBSD <acronym>IPsec</acronym> <quote>network stack</quote> is based
>+	on the <ulink url="http://www.kame.net/">KAME</ulink> implementation,
>+	which has support for both protocol families, IPv4 and IPv6.</para>
> 
>       <note>
>         <para>FreeBSD contains a <quote>hardware
>-        accelerated</quote> IPsec stack, known as <quote>Fast
>-        IPsec</quote>, that was obtained from OpenBSD.  It employs
>+        accelerated</quote> <acroonym>IPsec</acronym> stack, known as
>+	<quote>Fast IPsec</quote>, that was obtained from OpenBSD.  It employs
>         cryptographic hardware (whenever possible) via the
>-        &man.crypto.4; subsystem to optimize the performance of IPsec.
>+        &man.crypto.4; subsystem to optimize the performance of
>+	<acronym>IPsec.</acronym>
>         This subsystem is new, and does not support all the features
>-        that are available in the KAME version of IPsec.  However, in
>-        order to enable hardware-accelerated IPsec, the following
>+        that are available in the KAME version of <acronym>IPsec</acronym>.
>+	However, in order to enable hardware-accelerated
>+	<acronym>IPsec</acronym>, the following
>         kernel option has to be added to your kernel configuration
>         file:</para>
> 
>@@ -3105,8 +3125,8 @@
> 
>         <para> Note, that it is not currently possible to use the
> 	  <quote>Fast IPsec</quote> subsystem in lieu of the KAME
>-	  implementation of IPsec.  Consult the &man.fast.ipsec.4;
>-	  manual page for more information.</para>
>+	  implementation of <acronym>IPsec</acronym>.  Consult the
>+	  &man.fast.ipsec.4; manual page for more information.</para>
>       </note>
> 
>       <note>
>@@ -3130,23 +3150,25 @@
> 	<secondary>AH</secondary>
>       </indexterm>
> 
>-      <para>IPsec consists of two sub-protocols:</para>
>+      <para><acronym>IPsec</acronym> consists of two sub-protocols:</para>
> 
>       <itemizedlist>
>         <listitem>
>           <para><emphasis>Encapsulated Security Payload
>-	      (ESP)</emphasis>, protects the IP packet data from third
>-	    party interference, by encrypting the contents using
>+	    (<acronym role="Encapsulated Security Payload">ESP</acronym>)
>+	    </emphasis>, protects the <acronym>IP</acronym> packet data from
>+	    third party interference, by encrypting the contents using
> 	    symmetric cryptography algorithms (like Blowfish,
>-	    3DES).</para>
>+	    <acronym>3DES</acronym>).</para>
>         </listitem>
>         <listitem>
>-          <para><emphasis>Authentication Header (AH)</emphasis>,
>-	    protects the IP packet header from third party interference
>-	    and spoofing, by computing a cryptographic checksum and
>-	    hashing the IP packet header fields with a secure hashing
>-	    function.  This is then followed by an additional header
>-	    that contains the hash, to allow the information in the
>+          <para><emphasis>Authentication Header
>+	    (<acronym role="Authentication Header">AH</acronym>)</emphasis>,
>+	    protects the <acronym>IP</acronym> packet header from third party
>+	    interference and spoofing, by computing a cryptographic checksum
>+	    and hashing the <acronym>IP</acronym> packet header fields with a
>+	    secure hashing function.  This is then followed by an additional
>+	    header that contains the hash, to allow the information in the
> 	    packet to be authenticated.</para>
>         </listitem>
>       </itemizedlist>
>@@ -3164,18 +3186,19 @@
> 	<see>VPN</see>
>       </indexterm>
> 
>-      <para>IPsec can either be used to directly encrypt the traffic
>-	between two hosts (known as <emphasis>Transport
>-	  Mode</emphasis>); or to build <quote>virtual tunnels</quote>
>+      <para><acronym>IPsec</acronym> can either be used to directly encrypt
>+        the traffic between two hosts (known as <emphasis>Transport
>+	Mode</emphasis>); or to build <quote>virtual tunnels</quote>
> 	between two subnets, which could be used for secure
> 	communication between two corporate networks (known as
> 	<emphasis>Tunnel Mode</emphasis>).  The latter is more commonly
>-	known as a <emphasis>Virtual Private Network (VPN)</emphasis>.
>-	The &man.ipsec.4; manual page should be consulted for detailed
>-	information on the IPsec subsystem in FreeBSD.</para>
>+	known as a <emphasis>Virtual Private Network (<acronym>VPN</acronym>)
>+	</emphasis>. The &man.ipsec.4; manual page should be consulted for
>+	detailed information on the <acronym>IPsec</acronym> subsystem in
>+	&os;.</para>
>       
>-      <para>To add IPsec support to your kernel, add the following
>-	options to your kernel configuration file:</para>
>+      <para>To add <acronym>IPsec</acronym> support to your kernel, add the
>+        following options to your kernel configuration file:</para>
> 
>       <indexterm>
> 	<primary>kernel options</primary>
>@@ -3208,11 +3231,12 @@
>     <sect2>
>       <title>The Problem</title>
>  
>-      <para>There is no standard for what constitutes a VPN.  VPNs can
>-	be implemented using a number of different technologies, each of
>+      <para>There is no standard for what constitutes a <acronym>VPN</acronym>.
>+        <acronym>VPN</acronym>s can be implemented using a number of different
>+	technologies, each of
> 	which have their own strengths and weaknesses.  This section
> 	presents a scenario, and the strategies used for implementing a
>-	VPN for this scenario.</para>
>+	<acronym>VPN</acronym> for this scenario.</para>
>     </sect2>
>     
>     <sect2> 
>@@ -3231,33 +3255,36 @@
>           <para>You have at least two sites</para>
>         </listitem>
>         <listitem>
>-          <para>Both sites are using IP internally</para>
>+          <para>Both sites are using <acronym>IP</acronym> internally</para>
>         </listitem>
>         <listitem>
>           <para>Both sites are connected to the Internet, through a
>             gateway that is running FreeBSD.</para>
>         </listitem>
>         <listitem>
>-          <para>The gateway on each network has at least one public IP
>-            address.</para>
>+          <para>The gateway on each network has at least one public 
>+	    <acronym>IP</acronym>address.</para>
>         </listitem>
>         <listitem>
>           <para>The internal addresses of the two networks can be
>-            public or private IP addresses, it does not matter.  You can
>-            be running NAT on the gateway machine if necessary.</para>
>+            public or private <acronym>IP</acronym> addresses, it does not
>+	    matter.  You can be running 
>+	    <acronym role="Network Address Translation">NAT</acronym> on the
>+	    gateway machine if necessary.</para>
>         </listitem>
>         <listitem>
>-          <para>The internal IP addresses of the two networks
>-            <emphasis>do not collide</emphasis>.  While I expect it is
>-            theoretically possible to use a combination of VPN
>-            technology and NAT to get this to work, I expect it to be a
>+          <para>The internal <acronym>IP</acronym> addresses of the two
>+	    networks <emphasis>do not collide</emphasis>.  While I expect it
>+	    is theoretically possible to use a combination of
>+	    <acronym>VPN</acronym> technology and <acronym>NAT</acronym>
>+	    to get this to work, I expect it to be a
>             configuration nightmare.</para>
>         </listitem>
>       </itemizedlist>
>       
>       <para>If you find that you are trying to connect two networks,
>-        both of which, internally, use the same private IP address range
>-        (e.g. both of them use <hostid
>+        both of which, internally, use the same private <acronym>IP</acronym>
>+	address range (e.g. both of them use <hostid
>         role="ipaddr">192.168.1.x</hostid>), then one of the networks will
>         have to be renumbered.</para>
>  
>@@ -3293,14 +3320,16 @@
> 	</textobject>
>       </mediaobject>
>  
>-      <para>Notice the two public IP addresses.  I will use the letters to
>+      <para>Notice the two public <acronym>IP</acronym> addresses.  I will use
>+        the letters to
>         refer to them in the rest of this article.  Anywhere you see those
>         letters in this article, replace them with your own public IP
>         addresses.  Note also that internally, the two gateway
>-        machines have .1 IP addresses, and that the two networks have
>-        different private IP addresses (<hostid
>-        role="ipaddr">192.168.1.x</hostid> and <hostid
>-        role="ipaddr">192.168.2.x</hostid> respectively).  All the
>+        machines have <hostid role="ipaddr">.1</hostid> <acronym>IP</acronym>
>+	addresses, and that the two networks have different private
>+	<acronym>IP</acronym> addresses  
>+	(<hostid role="ipaddr">192.168.1.x</hostid> and 
>+	<hostid role="ipaddr">192.168.2.x</hostid> respectively).  All the
>         machines on the private networks have been configured to use the
>         <hostid role="ipaddr">.1</hostid> machine as their default
>         gateway.</para>
>@@ -3323,8 +3352,8 @@
>       <para>And the whole thing has to be secure.  This means that
>         traffic between the two networks has to be encrypted.</para>
>  
>-      <para>Creating a VPN between these two networks is a multi-step
>-        process.  The stages are as follows:</para>
>+      <para>Creating a <acronym>VPN</acronym> between these two networks is a
>+        multi-step process.  The stages are as follows:</para>
>  
>       <orderedlist>
>         <listitem>
>@@ -3343,7 +3372,7 @@
>         <listitem>
>           <para>Configure additional software on the FreeBSD gateways,
>             to allow &windows; machines to see one another across the
>-            VPN.</para>
>+            <acronym>VPN</acronym>.</para>
>         </listitem>
>       </orderedlist>
> 
>@@ -3400,9 +3429,9 @@
>         the public IP addresses, and two for the private IP
>         addresses.</para>
>  
>-      <para>Support for the gif device must be compiled in to the
>-        &os; kernel on both machines.  You can do this by adding the
>-        line:</para>
>+      <para>Support for the <devicename>gif</devicename> device must be
>+        compiled in to the &os; kernel on both machines.  You can do this by
>+	adding the line:</para>
>  
>       <programlisting>device gif</programlisting>
>  
>@@ -3410,8 +3439,9 @@
>         then compile, install, and reboot as normal.</para>
>  
>       <para>Configuring the tunnel is a two step process.  First the
>-        tunnel must be told what the outside (or public) IP addresses
>-        are, using &man.ifconfig.8;.  Then the private IP addresses must be
>+        tunnel must be told what the outside (or public) <acronym>IP</acronym>
>+	addresses are, using &man.ifconfig.8;.  Then the private 
>+	<acronym>IP</acronym> addresses must be
>         configured using &man.ifconfig.8;.</para>
>  
>       <para>On the gateway machine on network #1 you would run the
>@@ -3423,7 +3453,8 @@
>       </screen>
> 
>       <para>On the other gateway machine you run the same commands,
>-        but with the order of the IP addresses reversed.</para>
>+        but with the order of the <acronym>IP</acronym> addresses reversed.
>+	</para>
> 
>       <screen>&prompt.root; <userinput>ifconfig <replaceable>gif0</replaceable> create</userinput>
> &prompt.root; <userinput>ifconfig <replaceable>gif0</replaceable> tunnel <replaceable>W.X.Y.Z</replaceable> <replaceable>A.B.C.D</replaceable></userinput>
>@@ -3471,15 +3502,16 @@
>         shortly.</para>
>  
>       <para>It is likely that you are running a firewall on both
>-        machines.  This will need to be circumvented for your VPN
>-        traffic.  You might want to allow all traffic between both
>-        networks, or you might want to include firewall rules that
>-        protect both ends of the VPN from one another.</para>
>+        machines.  This will need to be circumvented for your 
>+	<acronym>VPN</acronym> traffic.  You might want to allow all traffic
>+	between both networks, or you might want to include firewall rules
>+	that protect both ends of the <acronym>VPN</acronym> from one
>+	another.</para>
>  
>       <para>It greatly simplifies testing if you configure the
>-        firewall to allow all traffic through the VPN.  You can always
>-        tighten things up later.  If you are using &man.ipfw.8; on the
>-        gateway machines then a command like</para>
>+        firewall to allow all traffic through the <acronym>VPN</acronym>.
>+	You can always tighten things up later.  If you are using &man.ipfw.8;
>+	on the gateway machines then a command like</para>
> 
>       <programlisting>ipfw add 1 allow ip from any to any via gif0</programlisting>
>  
>@@ -3487,9 +3519,10 @@
>         VPN, without affecting your other firewall rules.  Obviously
>         you will need to run this command on both gateway hosts.</para>
>  
>-      <para>This is sufficient to allow each gateway machine to ping
>-        the other.  On <hostid role="ipaddr">192.168.1.1</hostid>, you
>-        should be able to run</para>
>+      <para>This is sufficient to allow each gateway machine to
>+        <command>ping</command> the other.  On
>+	<hostid role="ipaddr">192.168.1.1</hostid>, you should be able to run
>+	</para>
>  
>       <programlisting>ping 192.168.2.1</programlisting>
>  
>@@ -3497,7 +3530,7 @@
>         thing on the other gateway machine.</para>
>  
>       <para>However, you will not be able to reach internal machines
>-        on either network yet.  This is because of the routing --
>+        on either network yet.  This is because of the routing &mdash;
>         although the gateway machines know how to reach one another,
>         they do not know how to reach the network behind each one.</para>
>  
>@@ -3516,12 +3549,12 @@
>         <hostid role="ipaddr">192.168.1.x</hostid> addresses
>         instead.</para>
>  
>-      <para>IP traffic from hosts on one network will now be able to
>-        reach hosts on the other network.</para>
>+      <para><acronym>IP</acronym> traffic from hosts on one network will now
>+        be able to reach hosts on the other network.</para>
>  
>-      <para>That has now created two thirds of a VPN between the two
>-        networks, in as much as it is <quote>virtual</quote> and it is a
>-        <quote>network</quote>.  It is not private yet.  You can test
>+      <para>That has now created two thirds of a <acronym>VPN</acronym> between
>+        the two networks, in as much as it is <quote>virtual</quote> and it is
>+	a <quote>network</quote>.  It is not private yet.  You can test
>         this using &man.ping.8; and &man.tcpdump.1;.  Log in to the
>         gateway host and run</para>
>  
>@@ -3542,10 +3575,10 @@
> 16:10:26.029112 192.168.1.1 &gt; 192.168.2.1: icmp: echo reply
>       </programlisting>
>  
>-      <para>As you can see, the ICMP messages are going back and forth
>-        unencrypted.  If you had used the <option>-s</option> parameter to
>-        &man.tcpdump.1; to grab more bytes of data from the packets you
>-        would see more information.</para>
>+      <para>As you can see, the <acronym>ICMP</acronym> messages are going
>+        back and forth unencrypted.  If you had used the <option>-s</option>
>+	parameter to &man.tcpdump.1; to grab more bytes of data from the
>+	packets you would see more information.</para>
>  
>       <para>Obviously this is unacceptable.  The next section will
>         discuss securing the link between the two networks so that it
>@@ -3586,7 +3619,8 @@
>     <sect3>
>       <title>Step 2: Securing the link</title>
>  
>-      <para>To secure the link we will be using IPsec.  IPsec provides
>+      <para>To secure the link we will be using <acronym>IPsec</acronym>.
>+        <acronym>IPsec</acronym> provides
>         a mechanism for two hosts to agree on an encryption key, and to
>         then use this key in order to encrypt data between the two
>         hosts.</para>
>@@ -3603,10 +3637,10 @@
>         <listitem>
>           <para>There must be a mechanism for specifying which traffic
>             should be encrypted.  Obviously, you do not want to encrypt
>-            all your outgoing traffic -- you only want to encrypt the
>-            traffic that is part of the VPN.  The rules that you put in
>-            place to determine what traffic will be encrypted are called
>-            <quote>security policies</quote>.</para>
>+            all your outgoing traffic &mdash; you only want to encrypt the
>+            traffic that is part of the <acronym>VPN</acronym>.  The rules
>+	    that you put in place to determine what traffic will be encrypted
>+	    are called <quote>security policies</quote>.</para>
>          </listitem>
>        </orderedlist>
>  
>@@ -3614,7 +3648,8 @@
>          maintained by the kernel, and can be modified by userland
>          programs.  However, before you can do this you must configure the
>          kernel to support IPsec and the Encapsulated Security Payload
>-         (ESP) protocol.  This is done by configuring a kernel with:</para>
>+         (<acronym>ESP</acronym>) protocol.  This is done by configuring a
>+	 kernel with:</para>
>  
>        <indexterm>
> 	 <primary>kernel options</primary>
>@@ -3637,7 +3672,9 @@
>          associations.  You can configure them by hand between two hosts,
>          which entails choosing the encryption algorithm, encryption keys,
>          and so forth, or you can use daemons that implement the Internet
>-         Key Exchange protocol (IKE) to do this for you.</para>
>+         Key Exchange protocol 
>+	 (<acronym role="Internet Key Exchange">IKE</acronym>) to do this
>+	 for you.</para>
>  
>        <para>I recommend the latter.  Apart from anything else, it is
>          easier to set up.</para>
>@@ -3662,26 +3699,28 @@
>        <para>There are a number of choices for daemons to manage
>          security associations with FreeBSD.  This article will describe
>          how to use one of these, racoon&nbsp;&mdash; which is available from
>-	 <filename role="package">security/ipsec-tools</filename> in the &os; Ports
>-	 collection.</para>
>+	 <filename role="package">security/ipsec-tools</filename> in the &os;
>+	 Ports Collection.</para>
>  
>        <indexterm>
> 	 <primary>racoon</primary>
>        </indexterm>
> 
>-       <para>The <application>racoon</application> software must be run on both gateway hosts.  On each host it
>-         is configured with the IP address of the other end of the VPN,
>-         and a secret key (which you choose, and must be the same on both
>-         gateways).</para>
>+       <para>The <application>racoon</application> software must be run on 
>+         both gateway hosts.  On each host it is configured with the 
>+	 <acronym>IP</acronym> address of the other end of the
>+	 <acronym>VPN</acronym>, and a secret key (which you choose, and
>+	 must be the same on both gateways).</para>
>  
>        <para>The two daemons then contact one another, confirm that they
>          are who they say they are (by using the secret key that you
>          configured).  The daemons then generate a new secret key, and use
>-         this to encrypt the traffic over the VPN.  They periodically
>+         this to encrypt the traffic over the <acronym>VPN</acronym>.  They
>+	 periodically
>          change this secret, so that even if an attacker were to crack one
>          of the keys (which is as theoretically close to unfeasible as it
>-         gets) it will not do them much good -- by the time they have cracked
>-         the key the two daemons have chosen another one.</para>
>+         gets) it will not do them much good &mdash; by the time they have
>+	 cracked the key the two daemons have chosen another one.</para>
>  
>        <para>The configuration file for racoon is stored in
>          <filename>${PREFIX}/etc/racoon</filename>.  You should find a
>@@ -3691,9 +3730,10 @@
>          key</quote>.</para>
>  
>        <para>The default racoon configuration expects to find this in
>-         the file <filename>${PREFIX}/etc/racoon/psk.txt</filename>.  It is important to note
>-         that the pre-shared key is <emphasis>not</emphasis> the key that will be used to
>-         encrypt your traffic across the VPN link, it is simply a token
>+         the file <filename>${PREFIX}/etc/racoon/psk.txt</filename>.  It is
>+	 important to note that the pre-shared key is <emphasis>not</emphasis>
>+	 the key that will be used to encrypt your traffic across the 
>+	 <acronym>VPN</acronym> link, it is simply a token
>          that allows the key management daemons to trust one another.</para>
> 
>        <para><filename>psk.txt</filename> contains a line for each
>@@ -3705,23 +3745,28 @@
>  
>        <programlisting>W.X.Y.Z            secret</programlisting>
>  
>-       <para>That is, the <emphasis>public</emphasis> IP address of the remote end,
>-         whitespace, and a text string that provides the secret.
>-         Obviously, you should not use <quote>secret</quote> as your key -- the normal
>+       <para>That is, the <emphasis>public</emphasis> <acronym>IP</acronym>
>+         address of the remote end, whitespace, and a text string that
>+	 provides the secret. Obviously, you should not use 
>+	 <quote>secret</quote> as your key &mdash; the normal
>          rules for choosing a password apply.</para>
>  
>        <para>On gateway host #2 the line would look like this</para>
>  
>        <programlisting>A.B.C.D            secret</programlisting>
>  
>-       <para>That is, the public IP address of the remote end, and the
>+       <para>That is, the public <acronym>IP</acronym> address of the remote
>+         end, and the
>          same secret key.  <filename>psk.txt</filename> must be mode
>          <literal>0600</literal> (i.e., only read/write to
>          <username>root</username>) before racoon will run.</para>
>  
>        <para>You must run racoon on both gateway machines.  You will
>-         also need to add some firewall rules to allow the IKE traffic,
>-         which is carried over UDP to the ISAKMP (Internet Security Association
>+         also need to add some firewall rules to allow the
>+	 <acronym>IKE</acronym> traffic,
>+         which is carried over <acronym>UDP</acronym> to the 
>+	 <acronym role="Internet Security Association Key Management
>+Protocol">ISAKMP</acronym> (Internet Security Association
>          Key Management Protocol) port.  Again, this should be fairly early in
>          your firewall ruleset.</para>
>  
>@@ -3732,7 +3777,7 @@
>        <para>Once racoon is running you can try pinging one gateway host
>          from the other.  The connection is still not encrypted, but
>          racoon will then set up the security associations between the two
>-         hosts -- this might take a moment, and you may see this as a
>+         hosts &mdash; this might take a moment, and you may see this as a
>          short delay before the ping commands start responding.</para>
>  
>        <para>Once the security association has been set up you can
>@@ -3750,12 +3795,14 @@
>          link.</para>
>  
>        <para>Each IP packet that you send out has a header that contains
>-         data about the packet.  The header includes the IP addresses of
>-         both the source and destination.  As we already know, private IP
>+         data about the packet.  The header includes the
>+	 <acronym>IP</acronym> addresses of both the source and destination.
>+	 As we already know, private <acronym>IP</acronym>
>          addresses, such as the <hostid role="ipaddr">192.168.x.y</hostid>
>          range are not supposed to appear on the public Internet.
>          Instead, they must first be encapsulated inside another packet.
>-         This packet must have the public source and destination IP
>+         This packet must have the public source and destination
>+	 <acronym>IP</acronym>
>          addresses substituted for the private addresses.</para>
>  
>        <para>So if your outgoing packet started looking like this:</para>
>@@ -3805,11 +3852,13 @@
>  
>        <para>This encapsulation is carried out by the
>          <devicename>gif</devicename> device.  As
>-         you can see, the packet now has real IP addresses on the outside,
>+         you can see, the packet now has real <acronym>IP<acronym> addresses
>+	 on the outside,
>          and our original packet has been wrapped up as data inside the
>          packet that will be put out on the Internet.</para>
>  
>-       <para>Obviously, we want all traffic between the VPNs to be
>+       <para>Obviously, we want all traffic between the
>+         <acronym>VPN</acronym>s to be
>          encrypted.  You might try putting this in to words, as:</para>
> 
>        <para><quote>If a packet leaves from <hostid
>@@ -3848,9 +3897,9 @@
>          filename that contains configuration instructions.</para>
>  
>        <para>The configuration on gateway host #1 (which has the public
>-         IP address <hostid role="ipaddr">A.B.C.D</hostid>) to force all
>-         outbound traffic to <hostid role="ipaddr">W.X.Y.Z</hostid> to be
>-         encrypted is:</para>
>+         <acronym>IP</acronym> address <hostid role="ipaddr">A.B.C.D</hostid>)
>+         to force all outbound traffic to <hostid role="ipaddr">W.X.Y.Z</hostid>
>+	 to be encrypted is:</para>
>  
>        <programlisting>
> spdadd A.B.C.D/32 W.X.Y.Z/32 ipencap -P out ipsec esp/tunnel/A.B.C.D-W.X.Y.Z/require;
>@@ -3865,7 +3914,8 @@
>          to add a rule to the secure policy database.  The rest of this
>          line specifies which packets will match this policy.  <hostid
>          role="ipaddr">A.B.C.D/32</hostid> and <hostid
>-         role="ipaddr">W.X.Y.Z/32</hostid> are the IP addresses and
>+         role="ipaddr">W.X.Y.Z/32</hostid> are the <acronym>IP</acronym>
>+	 addresses and
>          netmasks that identify the network or hosts that this policy will
>          apply to.  In this case, we want it to apply to traffic between
>          these two hosts.  <option>ipencap</option> tells the kernel that
>@@ -3893,15 +3943,16 @@
>          <option>out</option> in this case, and the necessary reversal of
>          the IP addresses.</para>
>  
>-       <para>The other gateway host (which has the public IP address
>-         <hostid role="ipaddr">W.X.Y.Z</hostid>) will need similar rules.</para>
>+       <para>The other gateway host (which has the public
>+         <acronym>IP</acronym> address <hostid role="ipaddr">W.X.Y.Z</hostid>)
>+         will need similar rules.</para>
>  
>        <programlisting>spdadd W.X.Y.Z/32 A.B.C.D/32 ipencap -P out ipsec esp/tunnel/W.X.Y.Z-A.B.C.D/require;
> spdadd A.B.C.D/32 W.X.Y.Z/32 ipencap -P in ipsec esp/tunnel/A.B.C.D-W.X.Y.Z/require;</programlisting>
>  
>-       <para>Finally, you need to add firewall rules to allow ESP and
>-        IPENCAP packets back and forth.  These rules will need to be
>-        added to both hosts.</para>
>+       <para>Finally, you need to add firewall rules to allow 
>+         <acronym>ESP</acronym> and <acronym>IPENCAP</acronym> packets back
>+	 and forth.  These rules will need to be added to both hosts.</para>
>  
>        <programlisting>ipfw add 1 allow esp from A.B.C.D to W.X.Y.Z
> ipfw add 1 allow esp from W.X.Y.Z to A.B.C.D
>@@ -3944,7 +3995,8 @@
> 	  </textobject>
> 	</mediaobject>
> 
>-       <para>When they are received by the far end of the VPN they will
>+       <para>When they are received by the far end of the
>+         <acronym>VPN</acronym> they will
>          first be decrypted (using the security associations that have
>          been negotiated by racoon).  Then they will enter the
>          <devicename>gif</devicename> interface, which will unwrap
>@@ -3966,12 +4018,13 @@
>  
>        <programlisting>XXX tcpdump output</programlisting>
>  
>-       <para>Now, as you can see, &man.tcpdump.1; shows the ESP packets.  If
>+       <para>Now, as you can see, &man.tcpdump.1; shows the
>+         <acronym>ESP</acronym> packets.  If
>          you try to examine them with the <option>-s</option> option you will see
>          (apparently) gibberish, because of the encryption.</para>
>  
>-      <para>Congratulations.  You have just set up a VPN between two
>-        remote sites.</para>
>+      <para>Congratulations.  You have just set up a <acronym>VPN</acronym>
>+        between two remote sites.</para>
>  
>       <itemizedlist>
>         <title>Summary</title>
>@@ -3986,7 +4039,8 @@
>           <para>Install <filename
>             role="package">security/ipsec-tools</filename>.  Edit
>             <filename>${PREFIX}/etc/racoon/psk.txt</filename> on both
>-            gateway hosts, adding an entry for the remote host's IP
>+            gateway hosts, adding an entry for the remote host's
>+	    <acronym>IP</acronym>
>             address and a secret key that they both know.  Make sure
>             this file is mode 0600.</para>
>         </listitem>
>@@ -4020,7 +4074,8 @@
> </programlisting>
>         </listitem>
>         <listitem>
>-          <para>Add firewall rules to allow IKE, ESP, and IPENCAP
>+          <para>Add firewall rules to allow <acronym>IKE</acronym>,
>+	    <acronym>ESP</acronym>, and <acronym>IPENCAP</acronym>
>             traffic to both hosts:</para>
>  
>           <programlisting>
>@@ -4034,10 +4089,11 @@
>         </listitem>
>       </itemizedlist>
> 
>-      <para>The previous two steps should suffice to get the VPN up and
>+      <para>The previous two steps should suffice to get the
>+       <acronym>VPN</acronym> up and
>         running.  Machines on each network will be able to refer to one
>-        another using IP addresses, and all traffic across the link will
>-        be automatically and securely encrypted.</para>
>+        another using <acronym>IP</acornym> addresses, and all traffic across
>+	the link will be automatically and securely encrypted.</para>
>     </sect3> 
>     </sect2> 
>   </sect1>
>@@ -4065,14 +4121,16 @@
>       access remote machines securely.  It can be used as a direct
>       replacement for <command>rlogin</command>,
>       <command>rsh</command>, <command>rcp</command>, and
>-      <command>telnet</command>.  Additionally, TCP/IP
>-      connections can be tunneled/forwarded securely through SSH.
>+      <command>telnet</command>.  Additionally, <acronym>TCP/IP</acronym>
>+      connections can be tunneled/forwarded securely through <acronym
>+      role="Secure Shell">SSH</acronym>.
>       <application>OpenSSH</application> encrypts all traffic to effectively eliminate eavesdropping,
>       connection hijacking, and other network-level attacks.</para>
> 
>-    <para><application>OpenSSH</application> is maintained by the OpenBSD project, and is based
>+    <para><application>OpenSSH</application> is maintained by the OpenBSD
>+      project, and is based
>       upon SSH v1.2.12 with all the recent bug fixes and updates.  It
>-      is compatible with both SSH protocols 1 and 2.</para>
>+      is compatible with both <acronym>SSH</acronym> protocols 1 and 2.</para>
> 
>     <sect2>
>       <title>Advantages of Using OpenSSH</title>
>@@ -4124,12 +4182,13 @@
> 
>       <para>The login will continue just as it would have if a session was
>         created using <command>rlogin</command> or
>-        <command>telnet</command>.  SSH utilizes a key fingerprint
>-        system for verifying the authenticity of the server when the 
>-        client connects.  The user is prompted to enter
>+        <command>telnet</command>.  <acronym>SSH</acronym> utilizes a key
>+	fingerprint system for verifying the authenticity of the server when
>+	the  client connects.  The user is prompted to enter
> 	<literal>yes</literal> only when
>         connecting for the first time.  Future attempts to login are all
>-        verified against the saved fingerprint key.  The SSH client
>+        verified against the saved fingerprint key.  The
>+	<acronym>SSH</acronym> client
>         will alert you if the saved fingerprint differs from the
>         received fingerprint on future login attempts.  The fingerprints
>         are saved in <filename>~/.ssh/known_hosts</filename>, or
>@@ -4137,7 +4196,8 @@
> 	fingerprints.</para>
> 
>       <para>By default, recent versions of the
>-        <application>OpenSSH</application> servers only accept SSH v2
>+        <application>OpenSSH</application> servers only accept
>+	<acronym>SSH</acronym>v2
>         connections.  The client will use version 2 if possible and
>         will fall back to version 1.  The client can also be forced to
>         use one or the other by passing it the <option>-1</option> or
>@@ -4170,8 +4230,8 @@
>       <para>The arguments passed to &man.scp.1; are similar
> 	to &man.cp.1;, with the file or files in the first
> 	argument, and the destination in the second.  Since the file is
>-	fetched over the network, through SSH, one or more of the file
>-	arguments takes on the form
>+	fetched over the network, through <acronym>SSH</acronym>, one or
>+	more of the file arguments takes on the form
> 	<option>user@host:&lt;path_to_remote_file&gt;</option>.</para>
> 
>     </sect2>
>@@ -4201,7 +4261,8 @@
>       <title>ssh-keygen</title>
> 
>       <para>Instead of using passwords, &man.ssh-keygen.1; can
>-        be used to generate DSA or RSA keys to authenticate a user:</para>
>+        be used to generate <acronym>DSA</acronym> or <acronym>RSA</acronym>
>+	keys to authenticate a user:</para>
> 
>       <screen>&prompt.user; <userinput>ssh-keygen -t <replaceable>dsa</replaceable></userinput>
> Generating public/private dsa key pair.
>@@ -4223,12 +4284,12 @@
>         <filename>~/.ssh/id_rsa.pub</filename>, respectively for DSA and
>         RSA key types.  The public key must be placed in
>         <filename>~/.ssh/authorized_keys</filename> of the remote
>-        machine in order for the setup to work.  Similarly, RSA version
>-        1 public keys should be placed in
>+        machine in order for the setup to work.  Similarly,
>+	<acronym>RSA</acronym> version 1 public keys should be placed in
>         <filename>~/.ssh/authorized_keys</filename>.</para>
> 
>       <para>This will allow connection to the remote machine based upon
>-        SSH keys instead of passwords.</para>
>+        <acronym>SSH</acronym> keys instead of passwords.</para>
> 
>       <para>If a passphrase is used in &man.ssh-keygen.1;, the user
>         will be prompted for a password each time in order to use the
>@@ -4246,7 +4307,7 @@
>       <title>ssh-agent and ssh-add</title>
> 
>       <para>The &man.ssh-agent.1; and &man.ssh-add.1; utilities provide
>-        methods for <application>SSH</application> keys to be loaded
>+        methods for <application>ssh</application> keys to be loaded
>         into memory for use, without needing to type the passphrase
>         each time.</para>
> 
>@@ -4283,7 +4344,7 @@
>         launch <application>XFCE</application>, every time X11 starts.
>         Then once that is done and X11 has been restarted so that the
>         changes can take effect, simply run &man.ssh-add.1; to load
>-        all of your SSH keys.</para>
>+        all of your <acronym>SSH</acronym> keys.</para>
>     </sect2>
> 
>     <sect2 id="security-ssh-tunneling">
>@@ -4312,7 +4373,7 @@
> 	  <listitem>
> 	    <para>Forces <command>ssh</command> to use version 2 of
> 	      the protocol. (Do not use if you are working with older
>-	      SSH servers)</para>
>+	      <acronym>SSH</acronym> servers)</para>
> 	  </listitem>
> 	</varlistentry>
> 
>@@ -4349,29 +4410,33 @@
> 	  <term><option>user@foo.example.com</option></term>
> 
> 	  <listitem>
>-	    <para>The remote SSH server.</para>
>+	    <para>The remote <acronym>SSH</acronym> server.</para>
> 	  </listitem>
> 	</varlistentry>
>       </variablelist>
> 
> 
>-      <para>An SSH tunnel works by creating a listen socket on
>-	<hostid>localhost</hostid> on the specified port.
>+      <para>A <acronym>SSH</acronym> tunnel works by creating a listen socket
>+        om <hostid>localhost</hostid> on the specified port.
> 	It then forwards any connection received
>-	on the local host/port via the SSH connection to the specified
>-	remote host and port.</para>
>+	on the local host/port via the <acronym>SSH</acronym> connection to
>+	the specified remote host and port.</para>
> 
>       <para>In the example, port <replaceable>5023</replaceable> on
> 	<hostid>localhost</hostid> is being forwarded to port
> 	<replaceable>23</replaceable> on <hostid>localhost</hostid>
>-	of the remote machine.  Since <replaceable>23</replaceable> is <application>telnet</application>,
>-	this would create a secure <application>telnet</application> session through an SSH tunnel.</para>
>-
>-      <para>This can be used to wrap any number of insecure TCP
>-        protocols such as SMTP, POP3, FTP, etc.</para>
>+	of the remote machine.  Since <replaceable>23</replaceable> is 
>+	<application>telnet</application>,
>+	this would create a secure <application>telnet</application> session
>+	through an <acronym>SSH</acronym> tunnel.</para>
>+
>+      <para>This can be used to wrap any number of insecure
>+        <acronym>TCP</acronym> protocols such as <acronym>SMTP</acronym>,
>+	<acronym>POP3</acronym>, <acronym>FTP</acronym>, etc.</para>
> 
>       <example>
>-	<title>Using SSH to Create a Secure Tunnel for SMTP</title>
>+	<title>Using <acronym>SSH</acronym> to Create a Secure Tunnel for
>+	  <acronym>SMTP</acronym></title>
> 
>         <screen>&prompt.user; <userinput>ssh -2 -N -f -L <replaceable>5025:localhost:25 user@mailserver.example.com</replaceable></userinput>
> user@mailserver.example.com's password: <userinput>*****</userinput>
>@@ -4383,52 +4448,55 @@
> 
>         <para>This can be used in conjunction with an
>           &man.ssh-keygen.1; and additional user accounts to create a
>-          more seamless/hassle-free SSH tunneling environment.  Keys
>-          can be used in place of typing a password, and the tunnels
>-          can be run as a separate user.</para>
>+          more seamless/hassle-free <acronym>SSH</acronym> tunneling
>+	  environment.  Keys can be used in place of typing a password, an
>+	  the tunnels can be run as a separate user.</para>
>       </example>
> 
>       <sect3>
>-	<title>Practical SSH Tunneling Examples</title>
>+	<title>Practical <acronym>SSH</acronym> Tunneling Examples</title>
> 
> 	<sect4>
>-	  <title>Secure Access of a POP3 Server</title>
>+	  <title>Secure Access of a <acronym>POP3</acronym> Server</title>
> 
>-	  <para>At work, there is an SSH server that accepts
>+	  <para>At work, there is an <acronym>SSH</acronym> server that accepts
> 	    connections from the outside.  On the same office network
>-	    resides a mail server running a POP3 server.  The network,
>+	    resides a mail server running a <acronym>POP3</acronym> server.
>+	    The network,
> 	    or network path between your home and office may or may not
> 	    be completely trustable.  Because of this, you need to check
> 	    your e-mail in a secure manner.  The solution is to create
>-	    an SSH connection to your office's SSH server, and tunnel
>+	    an <command>ssh</command> connection to your office's
>+	    <acronym>SSH</acronym> server, and tunnel
> 	    through to the mail server.</para>
> 
> 	  <screen>&prompt.user; <userinput>ssh -2 -N -f -L <replaceable>2110:mail.example.com:110 user@ssh-server.example.com</replaceable></userinput>
> user@ssh-server.example.com's password: <userinput>******</userinput></screen>
> 
> 	  <para>When the tunnel is up and running, you can point your
>-	    mail client to send POP3 requests to <hostid>localhost</hostid>
>+	    mail client to send <acronym>POP3</acronym> requests to
>+	    <hostid>localhost</hostid>
> 	    port 2110.  A connection here will be forwarded securely across
> 	    the tunnel to <hostid>mail.example.com</hostid>.</para>
> 	</sect4>
> 
> 	<sect4>
>-	  <title>Bypassing a Draconian Firewall</title>
>+	  <title>Bypassing a draconian Firewall</title>
> 
> 	  <para>Some network administrators impose extremely draconian
> 	    firewall rules, filtering not only incoming connections,
> 	    but outgoing connections.  You may be only given access
>-	    to contact remote machines on ports 22 and 80 for SSH
>-	    and web surfing.</para>
>+	    to contact remote machines on ports 22 and 80 for
>+	    <acronym>SSH</acronym> and web surfing.</para>
> 
> 	  <para>You may wish to access another (perhaps non-work
> 	    related) service, such as an Ogg Vorbis server to stream
> 	    music.  If this Ogg Vorbis server is streaming on some other
> 	    port than 22 or 80, you will not be able to access it.</para>
> 
>-	  <para>The solution is to create an SSH connection to a machine
>-	    outside of your network's firewall, and use it to tunnel to
>-	    the Ogg Vorbis server.</para>
>+	  <para>The solution is to create an <acronym>SSH</acronym> connection
>+	    to a machine outside of your network's firewall, and use it to
>+	    tunnel to the Ogg Vorbis server.</para>
> 
> 	  <screen>&prompt.user; <userinput>ssh -2 -N -f -L <replaceable>8888:music.example.com:8000 user@unfirewalled-system.example.org</replaceable></userinput>
> user@unfirewalled-system.example.org's password: <userinput>*******</userinput></screen>
>@@ -4501,7 +4569,7 @@
> 
>     <para>In conjunction with file system enhancements like snapshots, FreeBSD 5.0
>       and later offers the security of File System Access Control Lists
>-      (<acronym>ACLs</acronym>).</para>
>+      (<acronym role="Access Control Lists">ACLs</acronym>).</para>
> 
>     <para>Access Control Lists extend the standard &unix;
>       permission model in a highly compatible (&posix;.1e) way.  This feature

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Attachments on bug 106425: 73405