svn commit: r44952 - head/en_US.ISO8859-1/books/handbook/security
Warren Block <[email protected]>
| Newsgroups | gmane.os.freebsd.devel.cvs.doc |
|---|---|
| Message-ID | <[email protected]> |
Author: wblock
Date: Sun May 25 20:55:35 2014
New Revision: 44952
URL: http://svnweb.freebsd.org/changeset/doc/44952
Log:
Whitespace-only fixes. Translators, please ignore.
Modified:
head/en_US.ISO8859-1/books/handbook/security/chapter.xml
Modified: head/en_US.ISO8859-1/books/handbook/security/chapter.xml
==============================================================================
--- head/en_US.ISO8859-1/books/handbook/security/chapter.xml Sun May 25 16:32:53 2014 (r44951)
+++ head/en_US.ISO8859-1/books/handbook/security/chapter.xml Sun May 25 20:55:35 2014 (r44952)
@@ -4,7 +4,10 @@
$FreeBSD$
-->
-<chapter xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0" xml:id="security">
+<chapter xmlns="http://docbook.org/ns/docbook"
+ xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0"
+ xml:id="security">
+
<info>
<title>Security</title>
@@ -1083,35 +1086,46 @@ sendmail : PARANOID : deny</programlisti
<title><application>Kerberos</application></title>
<authorgroup>
- <author><personname><firstname>Tillman</firstname><surname>Hodgson</surname></personname><contrib>Contributed
- by </contrib></author>
+ <author>
+ <personname>
+ <firstname>Tillman</firstname>
+ <surname>Hodgson</surname>
+ </personname>
+ <contrib>Contributed by </contrib>
+ </author>
</authorgroup>
+
<authorgroup>
- <author><personname><firstname>Mark</firstname><surname>Murray</surname></personname><contrib>Based
- on a contribution by </contrib></author>
+ <author>
+ <personname>
+ <firstname>Mark</firstname>
+ <surname>Murray</surname>
+ </personname>
+ <contrib>Based on a contribution by </contrib>
+ </author>
</authorgroup>
</info>
<para><application>Kerberos</application> is a network
authentication protocol which was originally created by the
- Massachusetts Institute of Technology
- (<acronym>MIT</acronym>) as a way to securely provide authentication
- across a potentially hostile network.
- The <application>Kerberos</application> protocol uses
- strong cryptography so that both a client and server can prove
- their identity without sending any unencrypted secrets over the network.
- <application>Kerberos</application> can be described as an
- identity-verifying proxy system and as a trusted third-party
- authentication system. After a user authenticates with
- <application>Kerberos</application>, their communications can be
- encrypted to assure privacy and data integrity.</para>
+ Massachusetts Institute of Technology (<acronym>MIT</acronym>)
+ as a way to securely provide authentication across a potentially
+ hostile network. The <application>Kerberos</application>
+ protocol uses strong cryptography so that both a client and
+ server can prove their identity without sending any unencrypted
+ secrets over the network. <application>Kerberos</application>
+ can be described as an identity-verifying proxy system and as a
+ trusted third-party authentication system. After a user
+ authenticates with <application>Kerberos</application>, their
+ communications can be encrypted to assure privacy and data
+ integrity.</para>
<para>The only function of <application>Kerberos</application> is
- to provide the secure authentication of users and servers on the network.
- It does not provide authorization or auditing functions. It is
- recommended that <application>Kerberos</application> be used
- with other security methods which provide authorization and
- audit services.</para>
+ to provide the secure authentication of users and servers on the
+ network. It does not provide authorization or auditing
+ functions. It is recommended that
+ <application>Kerberos</application> be used with other security
+ methods which provide authorization and audit services.</para>
<para>The current version of the protocol is version 5, described
in <acronym>RFC</acronym> 4120. Several free
@@ -1123,18 +1137,20 @@ sendmail : PARANOID : deny</programlisti
<acronym>US</acronym> export regulations. In &os;,
<acronym>MIT</acronym> <application>Kerberos</application> is
available as the <package>security/krb5</package> package or
- port. The Heimdal <application>Kerberos</application> implementation was
- explicitly developed outside of the <acronym>US</acronym> to
- avoid export regulations. The Heimdal
+ port. The Heimdal <application>Kerberos</application>
+ implementation was explicitly developed outside of the
+ <acronym>US</acronym> to avoid export regulations. The Heimdal
<application>Kerberos</application> distribution is included in
the base &os; installation, and another distribution with more
- configurable options is available as <package>security/heimdal</package>
- in the Ports Collection.</para>
-
- <para>In <application>Kerberos</application> users and services are
- identified as <quote>principals</quote> which are contained within
- an administrative grouping, called a <quote>realm</quote>. A
- typical user principal would be of the form
+ configurable options is available as
+ <package>security/heimdal</package> in the Ports
+ Collection.</para>
+
+ <para>In <application>Kerberos</application> users and services
+ are identified as <quote>principals</quote> which are contained
+ within an administrative grouping, called a
+ <quote>realm</quote>. A typical user principal would be of the
+ form
<literal><replaceable>user</replaceable>@<replaceable>REALM</replaceable></literal>
(realms are traditionally uppercase).</para>
@@ -1177,14 +1193,15 @@ sendmail : PARANOID : deny</programlisti
<para>The Key Distribution Center (<acronym>KDC</acronym>) is
the centralized authentication service that
- <application>Kerberos</application> provides, the <quote>trusted
- third party</quote> of the system. It is the
+ <application>Kerberos</application> provides, the
+ <quote>trusted third party</quote> of the system. It is the
computer that issues <application>Kerberos</application>
- tickets, which are used for clients to authenticate to servers.
- Because the <acronym>KDC</acronym> is considered trusted by
- all other computers in the
- <application>Kerberos</application> realm, it has heightened security
- concerns. Direct access to the KDC should be limited.</para>
+ tickets, which are used for clients to authenticate to
+ servers. Because the <acronym>KDC</acronym> is considered
+ trusted by all other computers in the
+ <application>Kerberos</application> realm, it has heightened
+ security concerns. Direct access to the KDC should be
+ limited.</para>
<para>While running a <acronym>KDC</acronym> requires few
computing resources, a dedicated machine acting only as a
@@ -1219,9 +1236,9 @@ kadmind5_server_enable="YES"</programlis
<para><application>Kerberos</application> can also use the
<acronym>DNS</acronym> to locate KDCs, instead of a
<literal>[realms]</literal> section in
- <filename>/etc/krb5.conf</filename>. For large organizations that
- have their own <acronym>DNS</acronym> servers, the above example
- could be trimmed to:</para>
+ <filename>/etc/krb5.conf</filename>. For large organizations
+ that have their own <acronym>DNS</acronym> servers, the above
+ example could be trimmed to:</para>
<programlisting>[libdefaults]
default_realm = <replaceable>EXAMPLE.ORG</replaceable>
@@ -1252,22 +1269,22 @@ _kerberos IN TXT <replace
database which contains the keys of all principals (users and
hosts) encrypted with a master password. It is not required
to remember this password as it will be stored in
- <filename>/var/heimdal/m-key</filename>; it would be reasonable to
- use a 45-character random password for this purpose. To create the
- master key, run <command>kstash</command> and enter a
- password:</para>
+ <filename>/var/heimdal/m-key</filename>; it would be
+ reasonable to use a 45-character random password for this
+ purpose. To create the master key, run
+ <command>kstash</command> and enter a password:</para>
<screen>&prompt.root; <userinput>kstash</userinput>
Master key: <userinput><replaceable>xxxxxxxxxxxxxxxxxxxxxxx</replaceable></userinput>
Verifying password - Master key: <userinput><replaceable>xxxxxxxxxxxxxxxxxxxxxxx</replaceable></userinput></screen>
- <para>Once the master key has been created, the database should be
- initialized. The <application>Kerberos</application> administrative
- tool &man.kadmin.8; can be used on the KDC in a mode that
- operates directly on the database, without using the &man.kadmind.8;
- network service, as <command>kadmin -l</command>.
- This resolves the chicken-and-egg problem of trying to connect to
- the database
+ <para>Once the master key has been created, the database should
+ be initialized. The <application>Kerberos</application>
+ administrative tool &man.kadmin.8; can be used on the KDC in a
+ mode that operates directly on the database, without using the
+ &man.kadmind.8; network service, as
+ <command>kadmin -l</command>. This resolves the
+ chicken-and-egg problem of trying to connect to the database
before it is created. At the <command>kadmin</command>
prompt, use <command>init</command> to create the realm's
initial database:</para>
@@ -1299,10 +1316,11 @@ Verifying password - Password: <userinpu
principal that was just created:</para>
<screen>&prompt.user; <userinput>kinit <replaceable>tillman</replaceable></userinput>
[email protected]'s Password:
-</screen>
[email protected]'s Password:</screen>
+
<para>Confirm that a ticket was successfully obtained using
- <command>klist</command>:</para>
+ <command>klist</command>:</para>
+
<screen>&prompt.user; <userinput>klist</userinput>
Credentials cache: FILE:/tmp/krb5cc_1001
Principal: [email protected]
@@ -1333,49 +1351,52 @@ Aug 27 15:37:58 2013 Aug 28 01:37:58 20
regenerated on the new system.</para>
<para>Next, create <filename>/etc/krb5.keytab</filename> on the
- server. This is the main part of <quote>Kerberizing</quote> a service
- — it corresponds to generating a secret shared between the
- service and the <acronym>KDC</acronym>. The secret is a cryptographic
- key, stored in a <quote>keytab</quote>. The keytab contains
- the server's host key, which allows it and the <acronym>KDC</acronym>
- to verify each others' identity. It must be transmitted to the
- server in a secure fashion, as the security of the server can
- be broken if the key is made public. Typically, the
+ server. This is the main part of <quote>Kerberizing</quote> a
+ service — it corresponds to generating a secret shared
+ between the service and the <acronym>KDC</acronym>. The
+ secret is a cryptographic key, stored in a
+ <quote>keytab</quote>. The keytab contains the server's host
+ key, which allows it and the <acronym>KDC</acronym> to verify
+ each others' identity. It must be transmitted to the server
+ in a secure fashion, as the security of the server can be
+ broken if the key is made public. Typically, the
<filename>keytab</filename> is generated on an administrator's
trusted machine using <command>kadmin</command>, then securely
transferred to the server, e.g., with &man.scp.1;; it can also
be created directly on the server if that is consistent with
the desired security policy. It is very important that the
keytab is transmitted to the server in a secure fashion: if
- the key is known by some other party, that party can impersonate
- any user to the server! Using <command>kadmin</command> on the
- server directly is convenient, because the entry for the host
- principal in the <acronym>KDC</acronym> database is also created using
+ the key is known by some other party, that party can
+ impersonate any user to the server! Using
+ <command>kadmin</command> on the server directly is
+ convenient, because the entry for the host principal in the
+ <acronym>KDC</acronym> database is also created using
<command>kadmin</command>.</para>
- <para>Of course, <command>kadmin</command> is a kerberized service;
- a <application>Kerberos</application> ticket is needed to authenticate
- to the network service, but to ensure that the user running
- <command>kadmin</command> is actually present (and their session has
- not been hijacked), <command>kadmin</command> will prompt for the
- password to get a fresh ticket. The principal authenticating
- to the kadmin service must be permitted to use the
- <command>kadmin</command> interface, as specified in
- <filename>kadmind.acl</filename>. See the section titled
- <quote>Remote administration</quote> in <command>info
- heimdal</command> for details on designing access control
- lists. Instead of enabling remote <command>kadmin</command>
- access, the administrator could securely connect to the
- <acronym>KDC</acronym> via the local console or &man.ssh.1;,
- and perform administration locally using
- <command>kadmin -l</command>.</para>
+ <para>Of course, <command>kadmin</command> is a kerberized
+ service; a <application>Kerberos</application> ticket is
+ needed to authenticate to the network service, but to ensure
+ that the user running <command>kadmin</command> is actually
+ present (and their session has not been hijacked),
+ <command>kadmin</command> will prompt for the password to get
+ a fresh ticket. The principal authenticating to the kadmin
+ service must be permitted to use the <command>kadmin</command>
+ interface, as specified in <filename>kadmind.acl</filename>.
+ See the section titled <quote>Remote administration</quote> in
+ <command>info heimdal</command> for details on designing
+ access control lists. Instead of enabling remote
+ <command>kadmin</command> access, the administrator could
+ securely connect to the <acronym>KDC</acronym> via the local
+ console or &man.ssh.1;, and perform administration locally
+ using <command>kadmin -l</command>.</para>
<para>After installing <filename>/etc/krb5.conf</filename>,
- use <command>add --random-key</command> in <command>kadmin</command>.
- This adds the server's host principal to the database, but does not
- extract a copy of the host principal key to a keytab. To generate
- the keytab, use <command>ext</command> to extract the server's host
- principal key to its own keytab:</para>
+ use <command>add --random-key</command> in
+ <command>kadmin</command>. This adds the server's host
+ principal to the database, but does not extract a copy of the
+ host principal key to a keytab. To generate the keytab, use
+ <command>ext</command> to extract the server's host principal
+ key to its own keytab:</para>
<screen>&prompt.root; <userinput>kadmin</userinput>
kadmin><userinput> add --random-key host/myserver.example.org</userinput>
@@ -1387,11 +1408,12 @@ Attributes []:
kadmin><userinput> ext_keytab <replaceable>host/myserver.example.org</replaceable></userinput>
kadmin><userinput> exit</userinput></screen>
- <para>Note that <command>ext_keytab</command> stores the extracted key
- in <filename>/etc/krb5.keytab</filename> by default. This is
- good when being run on the server being kerberized, but the
- <command>--keytab <replaceable>path/to/file</replaceable></command>
- argument should be used when the keytab is being extracted
+ <para>Note that <command>ext_keytab</command> stores the
+ extracted key in <filename>/etc/krb5.keytab</filename> by
+ default. This is good when being run on the server being
+ kerberized, but the <command>--keytab
+ <replaceable>path/to/file</replaceable></command> argument
+ should be used when the keytab is being extracted
elsewhere:</para>
<screen>&prompt.root; <userinput>kadmin</userinput>
@@ -1400,23 +1422,25 @@ kadmin><userinput> exit</userinput></
<para>The keytab can then be securely copied to the server
using &man.scp.1; or a removable media. Be sure to specify a
- non-default keytab name to avoid inserting unneeded keys into the
- system's keytab.</para>
+ non-default keytab name to avoid inserting unneeded keys into
+ the system's keytab.</para>
- <para>At this point, the server can read encrypted messages from the
- <acronym>KDC</acronym> using its shared key, stored in
- <filename>krb5.keytab</filename>. It is now
- ready for the <application>Kerberos</application>-using services to
- be enabled. One of the most common such services is &man.sshd.8;,
- which supports <application>Kerberos</application> via the
+ <para>At this point, the server can read encrypted messages from
+ the <acronym>KDC</acronym> using its shared key, stored in
+ <filename>krb5.keytab</filename>. It is now ready for the
+ <application>Kerberos</application>-using services to be
+ enabled. One of the most common such services is
+ &man.sshd.8;, which supports
+ <application>Kerberos</application> via the
<acronym>GSS-API</acronym>. In
- <filename>/etc/ssh/sshd_config</filename>, add the line:</para>
+ <filename>/etc/ssh/sshd_config</filename>, add the
+ line:</para>
<programlisting>GSSAPIAuthentication yes</programlisting>
- <para>After making this change, &man.sshd.8; must be restared for
- the new configuration to take effect: <command>service sshd
- restart</command>.</para>
+ <para>After making this change, &man.sshd.8; must be restared
+ for the new configuration to take effect:
+ <command>service sshd restart</command>.</para>
</sect2>
<sect2>
@@ -1428,34 +1452,35 @@ kadmin><userinput> exit</userinput></
<secondary>configure clients</secondary>
</indexterm>
- <para>As it was for the server, the client requires configuration in
- <filename>/etc/krb5.conf</filename>. Copy the file in place
- (securely) or re-enter it as needed.</para>
+ <para>As it was for the server, the client requires
+ configuration in <filename>/etc/krb5.conf</filename>. Copy
+ the file in place (securely) or re-enter it as needed.</para>
<para>Test the client by using <command>kinit</command>,
<command>klist</command>, and <command>kdestroy</command> from
- the client to obtain, show, and then delete a ticket
- for an existing principal. <application>Kerberos</application>
+ the client to obtain, show, and then delete a ticket for an
+ existing principal. <application>Kerberos</application>
applications should also be able to connect to
<application>Kerberos</application> enabled servers. If that
does not work but obtaining a ticket does, the problem is
likely with the server and not with the client or the
- <acronym>KDC</acronym>. In the case of kerberized &man.ssh.1;,
- <acronym>GSS-API</acronym> is disabled by default, so test using
- <command>ssh -o GSSAPIAuthentication=yes
- <replaceable>hostname</replaceable></command>.</para>
+ <acronym>KDC</acronym>. In the case of kerberized
+ &man.ssh.1;, <acronym>GSS-API</acronym> is disabled by
+ default, so test using <command>ssh -o
+ GSSAPIAuthentication=yes
+ <replaceable>hostname</replaceable></command>.</para>
<para>When testing a Kerberized application, try using a packet
sniffer such as <command>tcpdump</command> to confirm that no
sensitive information is sent in the clear.</para>
<para>Various <application>Kerberos</application> client
- applications are available. With the advent of a bridge so that
- applications using <acronym>SASL</acronym> for authentication can
- use <acronym>GSS-API</acronym> mechanisms as well, large classes
- of client applications can use <application>Kerberos</application>
- for authentication, from Jabber clients to <acronym>IMAP</acronym>
- clients.</para>
+ applications are available. With the advent of a bridge so
+ that applications using <acronym>SASL</acronym> for
+ authentication can use <acronym>GSS-API</acronym> mechanisms
+ as well, large classes of client applications can use
+ <application>Kerberos</application> for authentication, from
+ Jabber clients to <acronym>IMAP</acronym> clients.</para>
<indexterm>
<primary><filename>.k5login</filename></primary>
@@ -1514,8 +1539,8 @@ [email protected]</screen>
<acronym>MIT</acronym> versions if <envar>PATH</envar> lists
the system directories first.</para>
- <para>When using MIT Kerberos as a <acronym>KDC</acronym> on &os;,
- the following edits should also be made to
+ <para>When using MIT Kerberos as a <acronym>KDC</acronym> on
+ &os;, the following edits should also be made to
<filename>rc.conf</filename>:</para>
<programlisting>kerberos5_server="/usr/local/sbin/krb5kdc"
@@ -1536,9 +1561,9 @@ kadmind5_server_enable="YES"</programlis
<itemizedlist>
<listitem>
<para>When using either Heimdal or <acronym>MIT</acronym>
- <application>Kerberos</application> from ports, ensure that the
- <envar>PATH</envar> lists the port's versions of the
- client applications before the system versions.</para>
+ <application>Kerberos</application> from ports, ensure
+ that the <envar>PATH</envar> lists the port's versions of
+ the client applications before the system versions.</para>
</listitem>
<listitem>
@@ -1580,15 +1605,16 @@ kadmind5_server_enable="YES"</programlis
<listitem>
<para>With <acronym>MIT</acronym>
- <application>Kerberos</application>, to allow a
- principal to have a ticket life longer than the default
- lifetime of ten hours, use <command>modify_principal</command>
- at the &man.kadmin.8; prompt to change the
+ <application>Kerberos</application>, to allow a principal
+ to have a ticket life longer than the default lifetime of
+ ten hours, use <command>modify_principal</command> at the
+ &man.kadmin.8; prompt to change the
<literal>maxlife</literal> of both the principal in
- question and the <systemitem
- class="username">krbtgt</systemitem> principal. The
- principal can then use <command>kinit -l</command> to
- request a ticket with a longer lifetime.</para>
+ question and the
+ <systemitem class="username">krbtgt</systemitem>
+ principal. The principal can then use
+ <command>kinit -l</command> to request a ticket with a
+ longer lifetime.</para>
</listitem>
<listitem>
@@ -1994,21 +2020,39 @@ Connection closed by foreign host.</scre
<sect1 xml:id="ipsec">
<info>
- <title><acronym>VPN</acronym> over
- <acronym>IPsec</acronym></title>
+ <title><acronym>VPN</acronym> over
+ <acronym>IPsec</acronym></title>
<authorgroup>
- <author><personname><firstname>Nik</firstname><surname>Clayton</surname></personname><affiliation>
- <address><email>[email protected]</email></address>
- </affiliation><contrib>Written by </contrib></author>
+ <author>
+ <personname>
+ <firstname>Nik</firstname>
+ <surname>Clayton</surname>
+ </personname>
+ <affiliation>
+ <address>
+ <email>[email protected]</email>
+ </address>
+ </affiliation>
+ <contrib>Written by </contrib>
+ </author>
</authorgroup>
- <authorgroup>
- <author><personname><firstname>Hiten
- M.</firstname><surname>Pandya</surname></personname><affiliation>
- <address><email>[email protected]</email></address>
- </affiliation><contrib>Written by </contrib></author>
- </authorgroup>
- </info>
+
+ <authorgroup>
+ <author>
+ <personname>
+ <firstname>Hiten M.</firstname>
+ <surname>Pandya</surname>
+ </personname>
+ <affiliation>
+ <address>
+ <email>[email protected]</email>
+ </address>
+ </affiliation>
+ <contrib>Written by </contrib>
+ </author>
+ </authorgroup>
+ </info>
<indexterm>
<primary><acronym>IPsec</acronym></primary>
@@ -2152,13 +2196,22 @@ device crypto</screen>
<sect2>
<info>
- <title>Configuring a <acronym>VPN</acronym> on &os;</title>
+ <title>Configuring a <acronym>VPN</acronym> on &os;</title>
- <authorgroup>
- <author><personname><firstname>Tom</firstname><surname>Rhodes</surname></personname><affiliation>
- <address><email>[email protected]</email></address>
- </affiliation><contrib>Written by </contrib></author>
- </authorgroup>
+ <authorgroup>
+ <author>
+ <personname>
+ <firstname>Tom</firstname>
+ <surname>Rhodes</surname>
+ </personname>
+ <affiliation>
+ <address>
+ <email>[email protected]</email>
+ </address>
+ </affiliation>
+ <contrib>Written by </contrib>
+ </author>
+ </authorgroup>
</info>
<para>To begin, <package>security/ipsec-tools</package> must be
@@ -2457,7 +2510,7 @@ racoon_enable="yes"</programlisting>
authentication and encryption methods to prevent this from
happening. More information about
<application>OpenSSH</application> is available from <link
- xlink:href="http://www.openssh.com/">http://www.openssh.com/</link>.</para>
+ xlink:href="http://www.openssh.com/">http://www.openssh.com/</link>.</para>
<para>This section provides an overview of the built-in client
utilities to securely access other systems and securely transfer
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