PHP Manual: ssh2

Description

resource ssh2_connect ( string host [, int port [, array methods [, array callbacks]]] )

Establish a connection to a remote SSH server and return a resource on success, FALSE on error.

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

Table 1. 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, come 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 client to server.

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

Table 2. 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, come separated in order of preference.	`hmac-sha1`, `hmac-sha1-96`, `hmac-ripemd160`, `hmac-ripemd160@openssh.com`, and `none**`

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.

Table 3. callbackss may be an associative array with any or all of the following 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)

Example 1. 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');
?>

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