ConFoo 2025

stream_socket_enable_crypto

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

stream_socket_enable_cryptoTurns encryption on/off on an already connected socket

Description

stream_socket_enable_crypto(
    resource $stream,
    bool $enable,
    ?int $crypto_method = null,
    ?resource $session_stream = null
): int|bool

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.

Return Values

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).

Changelog

Version Description
8.0.0 session_stream is now nullable.

Examples

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:


add a note

User Contributed Notes 4 notes

up
3
tigger (AT) tiggerswelt d0t net
17 years ago
As already mentioned above:

stream_socket_enable_crypto is likely to fail/return zero if the socket is in non-blocking mode.

You may either wait some seconds until all neccessary data has arrived or switch temporary to blocking mode:

<?PHP

stream_set_blocking
($fd, true);
stream_socket_enable_crypto ($fd, true, STREAM_CRYPTO_METHOD_TLS_CLIENT);
stream_set_blocking ($fd, false);

?>

This works very fine for me ;-)
up
2
Anonymous
2 years ago
If you need to change a stream from unencrypted to crypted after unencrypted traffic has been processed, you use the stream-socket-recvfrom function to read instead of fread when reading the unencrypted traffic. Using fread will cause some of the buffer of the initial CLIENT HELLO message to be read into it's buffers causing the SSL handshake to fail in some situations.
up
2
play dot it at play-it dot net
1 year ago
Information to the difference of `crypto_method`

There is `STREAM_CRYPTO_METHOD_*_CLIENT` and `STREAM_CRYPTO_METHOD_*_SERVER`

`STREAM_CRYPTO_METHOD_*_CLIENT` is used for clients, like:
```php
<?php
$client
= stream_socket_client("tcp://example.com:443", $errno, $errstr);
stream_socket_enable_crypto($client, true, STREAM_CRYPTO_METHOD_TLS_CLIENT);

//...
?>
```

This code makes a TLS Handshake and the `stream_socket_enable_crypto` sends a `Client HELLO`

`STREAM_CRYPTO_METHOD_*_SERVER` is used for servers, like:
<?php
$server
= stream_socket_server("tcp://example.com:443", $errno, $errstr, STREAM_SERVER_BIND | STREAM_SERVER_LISTEN);
stream_context_set_option($server, ["ssl" => [
"local_cert" => __DIR__."/https.crt",
"local_pk" => __DIR__."/https.key",
]]);

//...

$client = stream_socket_accept($server);
stream_socket_enable_crypto($client, true, STREAM_CRYPTO_METHOD_TLS_SERVER);

//...
?>

This code makes a TLS Handshake and the `stream_socket_enable_crypto` sends a `Server HELLO` after the client send a `Client HELLO`.

so use `STREAM_CRYPTO_METHOD_*_CLIENT` for requesting data and `STREAM_CRYPTO_METHOD_*_SERVER` for serving data, after accepting a client.
up
1
Zero
1 year ago
Since PHP 7.2, TLS equates to TLS_ANY, so STREAM_CRYPTO_METHOD_TLS_CLIENT means any TLS versions.
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