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<appref>
  <header>
    <copyright>
      <year>1999</year><year>2015</year>
      <holder>Ericsson AB. All Rights Reserved.</holder>
    </copyright>
    <legalnotice>
      Licensed under the Apache License, Version 2.0 (the "License");
      you may not use this file except in compliance with the License.
      You may obtain a copy of the License at
 
          http://www.apache.org/licenses/LICENSE-2.0

      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      See the License for the specific language governing permissions and
      limitations under the License.

    </legalnotice>

    <title>ssl</title>
    <prepared></prepared>
    <docno></docno>
    <date></date>
    <rev></rev>
    <file>ssl_app.sgml</file>
  </header>
  <app>ssl</app>
  <appsummary>The ssl application provides secure communication over
  sockets.</appsummary>

  <description></description>
  <section>
    <title>DEPENDENCIES</title>
    <p>The SSL application uses the <c>public_key</c> and
    Crypto application to handle public keys and encryption, hence
    these applications must be loaded for the SSL application to work. 
    In an embedded environment this means they must be started with
    <c>application:start/[1,2]</c> before the SSL application is 
    started.</p>
  </section>

  <section>
    <title>CONFIGURATION</title>
    <p>The application environment configuration parameters in this section 
    are defined for the SSL application. For more information 
    about configuration parameters, see the 
    <seealso marker="kernel:application">application(3)</seealso>
    manual page in Kernel.</p>

    <p>The environment parameters can be set on the command line,
    for example:</p>

    <p><c>erl -ssl protocol_version "['tlsv1.2', 'tlsv1.1']"</c></p>

    <taglist>
      <tag><c><![CDATA[protocol_version =  <seealso marker="kernel:error_logger">ssl:protocol()</seealso> <optional>]]></c>.</tag>
      <item><p>Protocol supported by started clients and
      servers. If this option is not set, it defaults to all
      protocols currently supported by the SSL application.
      This option can be overridden by the version option
      to <c>ssl:connect/[2,3]</c> and <c>ssl:listen/2</c>.</p></item>

      <tag><c><![CDATA[session_lifetime = integer() <optional>]]></c></tag>
      <item><p>Lifetime of the session data in seconds.</p></item>

      <tag><c><![CDATA[session_cb = atom() <optional>]]></c></tag>
      <item><p>Name of the session cache callback module that implements
      the <c>ssl_session_cache_api</c> behavior. Defaults to
      <c>ssl_session_cache.erl</c>.</p></item>

      <tag><c><![CDATA[session_cb_init_args = proplist:proplist() <optional>]]></c></tag>

      <item><p>List of extra user-defined arguments to the <c>init</c> function
      in the session cache callback module. Defaults to <c>[]</c>.</p></item>
      
      <tag><c><![CDATA[ssl_pem_cache_clean = integer() <optional>]]></c></tag>
      <item>
	<p>
	  Number of milliseconds between PEM cache validations.
	</p>
	<seealso
	    marker="ssl#clear_pem_cache-0">ssl:clear_pem_cache/0</seealso>
	
      </item>
    </taglist>
  </section>

  <section>
    <title>ERROR LOGGER AND EVENT HANDLERS</title>
    <p>The SSL application uses the default <seealso marker="kernel:error_logger">OTP error logger</seealso> to log unexpected errors and TLS alerts. The logging of TLS alerts may be turned off with the <c>log_alert</c> option. </p>
  </section>

  <section>
    <title>SEE ALSO</title>
	<p><seealso marker="kernel:application">application(3)</seealso></p>
  </section>
  
</appref>
