SSH2 Functions
PHP Manual

ssh2_connect

Connect to an SSH server

Description

resourcefalse ssh2_connect(
    string $host,
    int $port = 22,
    array $methods = ?,
    array $callbacks = ?
)

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');
?>

See Also

  • ssh2_fingerprint
  • ssh2_auth_none
  • ssh2_auth_password
  • ssh2_auth_pubkey_file
  • ssh2_disconnect