(PHP 5 >= 5.1.0)
stream_socket_enable_crypto — Turns encryption on/off on an already connected socket
$stream
   , bool $enable
   [, int $crypto_type
   [, resource $session_stream
  ]] )Enable or disable encryption on the stream.
   Once the crypto settings are established, cryptography can be turned
   on and off dynamically by passing TRUE or FALSE in the
   enable parameter.
  
streamThe stream resource.
enableEnable/disable cryptography on the stream.
crypto_typeSetup encryption on the stream. Valid methods are
STREAM_CRYPTO_METHOD_SSLv2_CLIENTSTREAM_CRYPTO_METHOD_SSLv3_CLIENTSTREAM_CRYPTO_METHOD_SSLv23_CLIENTSTREAM_CRYPTO_METHOD_TLS_CLIENTSTREAM_CRYPTO_METHOD_SSLv2_SERVERSTREAM_CRYPTO_METHOD_SSLv3_SERVERSTREAM_CRYPTO_METHOD_SSLv23_SERVERSTREAM_CRYPTO_METHOD_TLS_SERVER
       If omitted, the crypto_type context option on
       the stream's SSL context will be used instead.
      
session_stream
       Seed the stream with settings from session_stream.
      
   Returns TRUE on success, FALSE if negotiation has failed or
   0 if there isn't enough data and you should try again
   (only for non-blocking sockets).
  
| Version | Description | 
|---|---|
| 5.6.0 | The crypto_typeis now optional. | 
Example #1 stream_socket_enable_crypto() example
<?php
$fp = stream_socket_client("tcp://myproto.example.com:31337", $errno, $errstr, 30);
if (!$fp) {
    die("Unable to connect: $errstr ($errno)");
}
/* Turn on encryption for login phase */
stream_socket_enable_crypto($fp, true, STREAM_CRYPTO_METHOD_SSLv23_CLIENT);
fwrite($fp, "USER god\r\n");
fwrite($fp, "PASS secret\r\n");
/* Turn off encryption for the rest */
stream_socket_enable_crypto($fp, false);
while ($motd = fgets($fp)) {
    echo $motd;
}
fclose($fp);
?>
The above example will output something similar to: