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-rw-r--r--lib/ssl/doc/src/ssl_distribution.xml166
1 files changed, 125 insertions, 41 deletions
diff --git a/lib/ssl/doc/src/ssl_distribution.xml b/lib/ssl/doc/src/ssl_distribution.xml
index 61f88e3860..e14f3f90dc 100644
--- a/lib/ssl/doc/src/ssl_distribution.xml
+++ b/lib/ssl/doc/src/ssl_distribution.xml
@@ -4,7 +4,7 @@
<chapter>
<header>
<copyright>
- <year>2000</year><year>2016</year>
+ <year>2000</year><year>2017</year>
<holder>Ericsson AB. All Rights Reserved.</holder>
</copyright>
<legalnotice>
@@ -22,7 +22,7 @@
</legalnotice>
- <title>Using SSL for Erlang Distribution</title>
+ <title>Using TLS for Erlang Distribution</title>
<prepared>P Nyblom</prepared>
<responsible></responsible>
<docno></docno>
@@ -33,7 +33,7 @@
<file>ssl_distribution.xml</file>
</header>
<p>This section describes how the Erlang distribution can use
- SSL to get extra verification and security.</p>
+ TLS to get extra verification and security.</p>
<p>The Erlang distribution can in theory use almost any
connection-based protocol as bearer. However, a module that
@@ -45,16 +45,16 @@
<p>In the SSL application, an extra distribution
module, <c>inet_tls_dist</c>, can be used as an
- alternative. All distribution connections will use SSL and
+ alternative. All distribution connections will use TLS and
all participating Erlang nodes in a distributed system must use
this distribution module.</p>
<p>The security level depends on the parameters provided to the
- SSL connection setup. Erlang node cookies are however always
+ TLS connection setup. Erlang node cookies are however always
used, as they can be used to differentiate between two different
Erlang networks.</p>
- <p>To set up Erlang distribution over SSL:</p>
+ <p>To set up Erlang distribution over TLS:</p>
<list type="bulleted">
<item><em>Step 1:</em> Build boot scripts including the
@@ -63,13 +63,13 @@
<c>net_kernel</c>.</item>
<item><em>Step 3:</em> Specify the security options and other
SSL options.</item>
- <item><em>Step 4:</em> Set up the environment to always use SSL.</item>
+ <item><em>Step 4:</em> Set up the environment to always use TLS.</item>
</list>
<p>The following sections describe these steps.</p>
<section>
- <title>Building Boot Scripts Including the ssl Application</title>
+ <title>Building Boot Scripts Including the SSL Application</title>
<p>Boot scripts are built using the <c>systools</c> utility in the
SASL application. For more information on <c>systools</c>,
see the SASL documentation. This is only an example of
@@ -90,7 +90,7 @@
STDLIB application.</p></item>
</list>
- <p>The following shows an example <c>.rel</c> file with SSL
+ <p>The following shows an example <c>.rel</c> file with TLS
added:</p>
<code type="none">
{release, {"OTP APN 181 01","R15A"}, {erts, "5.9"},
@@ -154,7 +154,7 @@ Eshell V5.0 (abort with ^G)
<section>
<title>Specifying Distribution Module for net_kernel</title>
- <p>The distribution module for SSL is named <c>inet_tls_dist</c>
+ <p>The distribution module for SSL/TLS is named <c>inet_tls_dist</c>
and is specified on the command line with option <c>-proto_dist</c>.
The argument to <c>-proto_dist</c> is to be the module
name without suffix <c>_dist</c>. So, this distribution
@@ -174,21 +174,107 @@ Eshell V5.0 (abort with ^G)
(ssl_test@myhost)1> </code>
<p>However, a node started in this way refuses to talk
- to other nodes, as no SSL parameters are supplied
+ to other nodes, as no TLS parameters are supplied
(see the next section).</p>
</section>
<section>
- <title>Specifying SSL Options</title>
- <p>For SSL to work, at least
- a public key and a certificate must be specified for the server
- side. In the following example, the PEM-files consist of two
- entries, the server certificate and its private key.</p>
+ <title>Specifying SSL/TLS Options</title>
+
+ <p>
+ The SSL/TLS distribution options can be written into a file
+ that is consulted when the node is started. This file name
+ is then specified with the command line argument
+ <c>-ssl_dist_optfile</c>.
+ </p>
+ <p>
+ Any available SSL/TLS option can be specified in an options file,
+ but note that options that take a <c>fun()</c> has to use
+ the syntax <c>fun Mod:Func/Arity</c> since a function
+ body can not be compiled when consulting a file.
+ </p>
+ <p>
+ Do not tamper with the socket options
+ <c>list</c>, <c>binary</c>, <c>active</c>, <c>packet</c>,
+ <c>nodelay</c> and <c>deliver</c> since they are used
+ by the distribution protocol handler itself.
+ Other raw socket options such as <c>packet_size</c> may
+ interfere severely, so beware!
+ </p>
+ <p>
+ For SSL/TLS to work, at least a public key and a certificate
+ must be specified for the server side.
+ In the following example, the PEM file
+ <c>"/home/me/ssl/erlserver.pem"</c> contains both
+ the server certificate and its private key.
+ </p>
+ <p>
+ Create a file named for example
+ <c>"/home/me/ssl/[email protected]"</c>:
+ </p>
+ <code type="none"><![CDATA[
+[{server,
+ [{certfile, "/home/me/ssl/erlserver.pem"},
+ {secure_renegotiate, true}]},
+ {client,
+ [{secure_renegotiate, true}]}].]]>
+ </code>
+ <p>
+ And then start the node like this
+ (line breaks in the command are for readability,
+ and shall not be there when typed):
+ </p>
+ <code type="none"><![CDATA[
+$ erl -boot /home/me/ssl/start_ssl -proto_dist inet_tls
+ -ssl_dist_optfile "/home/me/ssl/[email protected]"
+ -sname ssl_test]]>
+ </code>
+ <p>
+ The options in the <c>{server, Opts}</c> tuple are used
+ when calling <c>ssl:ssl_accept/3</c>, and the options in the
+ <c>{client, Opts}</c> tuple are used when calling
+ <c>ssl:connect/4</c>.
+ </p>
+ <p>
+ For the client, the option
+ <c>{server_name_indication, atom_to_list(TargetNode)}</c>
+ is added when connecting.
+ This makes it possible to use the client option
+ <c>{verify, verify_peer}</c>,
+ and the client will verify that the certificate matches
+ the node name you are connecting to.
+ This only works if the the server certificate is issued
+ to the name <c>atom_to_list(TargetNode)</c>.
+ </p>
+ <p>
+ For the server it is also possible to use the option
+ <c>{verify, verify_peer}</c> and the server will only accept
+ client connections with certificates that are trusted by
+ a root certificate that the server knows.
+ A client that presents an untrusted certificate will be rejected.
+ This option is preferably combined with
+ <c>{fail_if_no_peer_cert, true}</c> or a client will
+ still be accepted if it does not present any certificate.
+ </p>
+ <p>
+ A node started in this way is fully functional, using TLS
+ as the distribution protocol.
+ </p>
+ </section>
+
+ <section>
+ <title>Specifying SSL/TLS Options (Legacy)</title>
+
+ <p>
+ As in the previous section the PEM file
+ <c>"/home/me/ssl/erlserver.pem"</c> contains both
+ the server certificate and its private key.
+ </p>
<p>On the <c>erl</c> command line you can specify options that the
- SSL distribution adds when creating a socket.</p>
+ SSL/TLS distribution adds when creating a socket.</p>
- <p>The simplest SSL options in the following list can be specified
+ <p>The simplest SSL/TLS options in the following list can be specified
by adding the
prefix <c>server_</c> or <c>client_</c> to the option name:</p>
<list type="bulleted">
@@ -208,7 +294,7 @@ Eshell V5.0 (abort with ^G)
</list>
<p>Note that <c>verify_fun</c> needs to be written in a different
- form than the corresponding SSL option, since funs are not
+ form than the corresponding SSL/TLS option, since funs are not
accepted on the command line.</p>
<p>The server can also take the options <c>dhfile</c> and
@@ -221,32 +307,34 @@ Eshell V5.0 (abort with ^G)
<p>Raw socket options, such as <c>packet</c> and <c>size</c> must not
be specified on the command line.</p>
- <p>The command-line argument for specifying the SSL options is named
+ <p>The command-line argument for specifying the SSL/TLS options is named
<c>-ssl_dist_opt</c> and is to be followed by pairs of
SSL options and their values. Argument <c>-ssl_dist_opt</c> can
be repeated any number of times.</p>
- <p>An example command line can now look as follows
+ <p>
+ An example command line doing the same as the example
+ in the previous section can now look as follows
(line breaks in the command are for readability,
- and are not be there when typed):</p>
- <code type="none">
+ and shall not be there when typed):
+ </p>
+ <code type="none"><![CDATA[
$ erl -boot /home/me/ssl/start_ssl -proto_dist inet_tls
- -ssl_dist_opt server_certfile "/home/me/ssl/erlserver.pem"
+ -ssl_dist_opt server_certfile "/home/me/ssl/erlserver.pem"
-ssl_dist_opt server_secure_renegotiate true client_secure_renegotiate true
-sname ssl_test
Erlang (BEAM) emulator version 5.0 [source]
-
+
Eshell V5.0 (abort with ^G)
-(ssl_test@myhost)1> </code>
- <p>A node started in this way is fully functional, using SSL
- as the distribution protocol.</p>
+(ssl_test@myhost)1>]]>
+ </code>
</section>
<section>
- <title>Setting up Environment to Always Use SSL</title>
+ <title>Setting up Environment to Always Use SSL/TLS (Legacy)</title>
<p>A convenient way to specify arguments to Erlang is to use environment
variable <c>ERL_FLAGS</c>. All the flags needed to
- use the SSL distribution can be specified in that variable and are
+ use the SSL/TLS distribution can be specified in that variable and are
then interpreted as command-line arguments for all
subsequent invocations of Erlang.</p>
@@ -277,25 +365,21 @@ Eshell V5.0 (abort with ^G)
</section>
<section>
- <title>Using SSL distribution over IPv6</title>
- <p>It is possible to use SSL distribution over IPv6 instead of
+ <title>Using SSL/TLS distribution over IPv6</title>
+ <p>It is possible to use SSL/TLS distribution over IPv6 instead of
IPv4. To do this, pass the option <c>-proto_dist inet6_tls</c>
instead of <c>-proto_dist inet_tls</c> when starting Erlang,
either on the command line or in the <c>ERL_FLAGS</c> environment
variable.</p>
<p>An example command line with this option would look like this:</p>
- <code type="none">
+ <code type="none"><![CDATA[
$ erl -boot /home/me/ssl/start_ssl -proto_dist inet6_tls
- -ssl_dist_opt server_certfile "/home/me/ssl/erlserver.pem"
- -ssl_dist_opt server_secure_renegotiate true client_secure_renegotiate true
- -sname ssl_test
-Erlang (BEAM) emulator version 5.0 [source]
-
-Eshell V5.0 (abort with ^G)
-(ssl_test@myhost)1> </code>
+ -ssl_dist_optfile "/home/me/ssl/[email protected]"
+ -sname ssl_test]]>
+ </code>
<p>A node started in this way will only be able to communicate with
- other nodes using SSL distribution over IPv6.</p>
+ other nodes using SSL/TLS distribution over IPv6.</p>
</section>
</chapter>