ssh2_connect

(PECL ssh2 >= 0.9.0)

ssh2_connect — Connect to an SSH server

Description

ssh2_connect(
    string $host,
    int $port = 22,
    array $methods = ?,
    array $callbacks = ?
): resource|false

Establish a connection to a remote SSH server.

Once connected, the client should verify the server's hostkey using ssh2_fingerprint(), then authenticate using either password or public key.

Parameters

host

port

methods

methods may be an associative array with up to four parameters as described below.

**`methods` may be an associative array with any or all of the following parameters.**
Index	Meaning	Supported Values*
kex	List of key exchange methods to advertise, comma separated in order of preference.	`diffie-hellman-group1-sha1`, `diffie-hellman-group14-sha1`, and `diffie-hellman-group-exchange-sha1`
hostkey	List of hostkey methods to advertise, comma separated in order of preference.	`ssh-rsa` and `ssh-dss`
client_to_server	Associative array containing crypt, compression, and message authentication code (MAC) method preferences for messages sent from client to server.
server_to_client	Associative array containing crypt, compression, and message authentication code (MAC) method preferences for messages sent from server to client.

* - Supported Values are dependent on methods supported by underlying library. See » libssh2 documentation for additional information.

**`client_to_server` and `server_to_client` may be an associative array with any or all of the following parameters.**
Index	Meaning	Supported Values*
crypt	List of crypto methods to advertise, comma separated in order of preference.	`rijndael-cbc@lysator.liu.se`, `aes256-cbc`, `aes192-cbc`, `aes128-cbc`, `3des-cbc`, `blowfish-cbc`, `cast128-cbc`, `arcfour`, and `none**`
comp	List of compression methods to advertise, comma separated in order of preference.	`zlib` and `none`
mac	List of MAC methods to advertise, comma separated in order of preference.	`hmac-sha1`, `hmac-sha1-96`, `hmac-ripemd160`, `hmac-ripemd160@openssh.com`, and `none**`

Note: Crypt and MAC method "none"

For security reasons, none is disabled by the underlying » libssh2 library unless explicitly enabled during build time by using the appropriate ./configure options. See documentation for the underlying library for more information.

callbacks

callbacks may be an associative array with any or all of the following parameters.

**Callbacks parameters**
Index	Meaning	Prototype
ignore	Name of function to call when an `SSH2_MSG_IGNORE` packet is received	void ignore_cb($message)
debug	Name of function to call when an `SSH2_MSG_DEBUG` packet is received	void debug_cb($message, $language, $always_display)
macerror	Name of function to call when a packet is received but the message authentication code failed. If the callback returns `true`, the mismatch will be ignored, otherwise the connection will be terminated.	bool macerror_cb($packet)
disconnect	Name of function to call when an `SSH2_MSG_DISCONNECT` packet is received	void disconnect_cb($reason, $message, $language)

Return Values

Returns a resource on success, or false on error.

Examples

Example #1 ssh2_connect() example

Open a connection forcing 3des-cbc when sending packets, any strength aes cipher when receiving packets, no compression in either direction, and Group1 key exchange.


<?php
/* Notify the user if the server terminates the connection */
function my_ssh_disconnect($reason, $message, $language) {
  printf("Server disconnected with reason code [%d] and message: %s\n",
         $reason, $message);
}

$methods = array(
  'kex' => 'diffie-hellman-group1-sha1',
  'client_to_server' => array(
    'crypt' => '3des-cbc',
    'comp' => 'none'),
  'server_to_client' => array(
    'crypt' => 'aes256-cbc,aes192-cbc,aes128-cbc',
    'comp' => 'none'));

$callbacks = array('disconnect' => 'my_ssh_disconnect');

$connection = ssh2_connect('shell.example.com', 22, $methods, $callbacks);
if (!$connection) die('Connection failed');
?>