xenial (7) ssl.7.gz

NAME

       ssl - The ssl application provides secure communication over
         sockets.

DESCRIPTION

       The ssl application is an implementation of the SSL/TLS protocol in Erlang.

         * Supported SSL/TLS-versions are SSL-3.0, TLS-1.0, TLS-1.1, and TLS-1.2.

         * For security reasons SSL-2.0 is not supported.

         * For security reasons SSL-3.0 is no longer supported by default, but can be configured.

         * Ephemeral  Diffie-Hellman  cipher  suites  are  supported, but not Diffie Hellman Certificates cipher
           suites.

         * Elliptic Curve cipher suites are supported if the Crypto application supports it and named curves are
           used.

         * Export cipher suites are not supported as the U.S. lifted its export restrictions in early 2000.

         * IDEA  cipher  suites are not supported as they have become deprecated by the latest TLS specification
           so it is not motivated to implement them.

         * CRL validation is supported.

         * Policy certificate extensions are not supported.

         * 'Server Name Indication' extension client side (RFC 6066, Section 3) is supported.

DEPENDENCIES

       The SSL application uses the public_key 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 application:start/[1,2] before the SSL application is started.

CONFIGURATION

       The application environment configuration parameters in this section are defined for the SSL application.
       For more information about configuration parameters, see the application(3erl) manual page in Kernel.

       The environment parameters can be set on the command line, for example:

       erl -ssl protocol_version "['tlsv1.2', 'tlsv1.1']"

         protocol_version = ssl:protocol()<optional>:
           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 ssl:connect/[2,3] and ssl:listen/2.

         session_lifetime = integer() <optional>:
           Maximum lifetime of the session data in seconds.

         session_cb = atom() <optional>:
           Name  of  the  session  cache  callback  module  that  implements the ssl_session_cache_api behavior.
           Defaults to ssl_session_cache.

         session_cb_init_args = proplist:proplist() <optional>:
           List of extra user-defined arguments to the init function  in  the  session  cache  callback  module.
           Defaults to [].

         session_cache_client_max = integer() <optional>
           session_cache_server_max  =  integer()  <optional>:  Limits the growth of the clients/servers session
           cache, if the maximum number of sessions is reached, the current cache entries  will  be  invalidated
           regardless of their remaining lifetime. Defaults to 1000.

         ssl_pem_cache_clean = integer() <optional>:
           Number of milliseconds between PEM cache validations.ssl:clear_pem_cache/0

         alert_timeout = integer() <optional>:
           Number  of milliseconds between sending of a fatal alert and closing the connection. Waiting a little
           while improves the peers chances to properly receiving the  alert  so  it  may  shutdown  gracefully.
           Defaults to 5000 milliseconds.

ERROR LOGGER AND EVENT HANDLERS

       The  SSL  application  uses  the  default  OTP  error logger to log unexpected errors and TLS alerts. The
       logging of TLS alerts may be turned off with the log_alert option.

SEE ALSO

       application(3erl)