/**
* Key Exchange
*
* @param String $kexinit_payload_server
* @access private
*/
function _key_exchange($kexinit_payload_server)
{
static $kex_algorithms = array('diffie-hellman-group1-sha1', 'diffie-hellman-group14-sha1');
static $server_host_key_algorithms = array('ssh-rsa', 'ssh-dss');
static $encryption_algorithms = false;
if ($encryption_algorithms === false) {
$encryption_algorithms = array('arcfour256', 'arcfour128', 'arcfour', 'aes128-ctr', 'aes192-ctr', 'aes256-ctr', 'twofish128-ctr', 'twofish192-ctr', 'twofish256-ctr', 'aes128-cbc', 'aes192-cbc', 'aes256-cbc', 'twofish128-cbc', 'twofish192-cbc', 'twofish256-cbc', 'twofish-cbc', 'blowfish-ctr', 'blowfish-cbc', '3des-ctr', '3des-cbc', 'none');
if (phpseclib_resolve_include_path('Crypt/RC4.php') === false) {
$encryption_algorithms = array_diff($encryption_algorithms, array('arcfour256', 'arcfour128', 'arcfour'));
}
if (phpseclib_resolve_include_path('Crypt/Rijndael.php') === false) {
$encryption_algorithms = array_diff($encryption_algorithms, array('aes128-ctr', 'aes192-ctr', 'aes256-ctr', 'aes128-cbc', 'aes192-cbc', 'aes256-cbc'));
}
if (phpseclib_resolve_include_path('Crypt/Twofish.php') === false) {
$encryption_algorithms = array_diff($encryption_algorithms, array('twofish128-ctr', 'twofish192-ctr', 'twofish256-ctr', 'twofish128-cbc', 'twofish192-cbc', 'twofish256-cbc', 'twofish-cbc'));
}
if (phpseclib_resolve_include_path('Crypt/Blowfish.php') === false) {
$encryption_algorithms = array_diff($encryption_algorithms, array('blowfish-ctr', 'blowfish-cbc'));
}
if (phpseclib_resolve_include_path('Crypt/TripleDES.php') === false) {
$encryption_algorithms = array_diff($encryption_algorithms, array('3des-ctr', '3des-cbc'));
}
$encryption_algorithms = array_values($encryption_algorithms);
}
$mac_algorithms = array('hmac-sha1-96', 'hmac-sha1', 'hmac-md5-96', 'hmac-md5', 'none');
static $compression_algorithms = array('none');
// some SSH servers have buggy implementations of some of the above algorithms
switch ($this->server_identifier) {
case 'SSH-2.0-SSHD':
$mac_algorithms = array_values(array_diff($mac_algorithms, array('hmac-sha1-96', 'hmac-md5-96')));
}
static $str_kex_algorithms, $str_server_host_key_algorithms, $encryption_algorithms_server_to_client, $mac_algorithms_server_to_client, $compression_algorithms_server_to_client, $encryption_algorithms_client_to_server, $mac_algorithms_client_to_server, $compression_algorithms_client_to_server;
if (empty($str_kex_algorithms)) {
$str_kex_algorithms = implode(',', $kex_algorithms);
$str_server_host_key_algorithms = implode(',', $server_host_key_algorithms);
$encryption_algorithms_server_to_client = $encryption_algorithms_client_to_server = implode(',', $encryption_algorithms);
$mac_algorithms_server_to_client = $mac_algorithms_client_to_server = implode(',', $mac_algorithms);
$compression_algorithms_server_to_client = $compression_algorithms_client_to_server = implode(',', $compression_algorithms);
}
$client_cookie = crypt_random_string(16);
$response = $kexinit_payload_server;
$this->_string_shift($response, 1);
// skip past the message number (it should be SSH_MSG_KEXINIT)
$server_cookie = $this->_string_shift($response, 16);
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->kex_algorithms = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->server_host_key_algorithms = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->encryption_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->encryption_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->mac_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->mac_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->compression_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->compression_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->languages_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->languages_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
extract(unpack('Cfirst_kex_packet_follows', $this->_string_shift($response, 1)));
$first_kex_packet_follows = $first_kex_packet_follows != 0;
// the sending of SSH2_MSG_KEXINIT could go in one of two places. this is the second place.
$kexinit_payload_client = pack('Ca*Na*Na*Na*Na*Na*Na*Na*Na*Na*Na*CN', NET_SSH2_MSG_KEXINIT, $client_cookie, strlen($str_kex_algorithms), $str_kex_algorithms, strlen($str_server_host_key_algorithms), $str_server_host_key_algorithms, strlen($encryption_algorithms_client_to_server), $encryption_algorithms_client_to_server, strlen($encryption_algorithms_server_to_client), $encryption_algorithms_server_to_client, strlen($mac_algorithms_client_to_server), $mac_algorithms_client_to_server, strlen($mac_algorithms_server_to_client), $mac_algorithms_server_to_client, strlen($compression_algorithms_client_to_server), $compression_algorithms_client_to_server, strlen($compression_algorithms_server_to_client), $compression_algorithms_server_to_client, 0, '', 0, '', 0, 0);
if (!$this->_send_binary_packet($kexinit_payload_client)) {
return false;
}
// here ends the second place.
// we need to decide upon the symmetric encryption algorithms before we do the diffie-hellman key exchange
for ($i = 0; $i < count($encryption_algorithms) && !in_array($encryption_algorithms[$i], $this->encryption_algorithms_server_to_client); $i++) {
}
if ($i == count($encryption_algorithms)) {
user_error('No compatible server to client encryption algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
// we don't initialize any crypto-objects, yet - we do that, later. for now, we need the lengths to make the
// diffie-hellman key exchange as fast as possible
$decrypt = $encryption_algorithms[$i];
switch ($decrypt) {
case '3des-cbc':
case '3des-ctr':
$decryptKeyLength = 24;
// eg. 192 / 8
break;
case 'aes256-cbc':
case 'aes256-ctr':
case 'twofish-cbc':
case 'twofish256-cbc':
case 'twofish256-ctr':
$decryptKeyLength = 32;
// eg. 256 / 8
break;
case 'aes192-cbc':
case 'aes192-ctr':
case 'twofish192-cbc':
case 'twofish192-ctr':
$decryptKeyLength = 24;
// eg. 192 / 8
break;
case 'aes128-cbc':
case 'aes128-ctr':
case 'twofish128-cbc':
case 'twofish128-ctr':
case 'blowfish-cbc':
case 'blowfish-ctr':
$decryptKeyLength = 16;
// eg. 128 / 8
break;
case 'arcfour':
case 'arcfour128':
$decryptKeyLength = 16;
// eg. 128 / 8
break;
case 'arcfour256':
$decryptKeyLength = 32;
// eg. 128 / 8
break;
case 'none':
$decryptKeyLength = 0;
}
for ($i = 0; $i < count($encryption_algorithms) && !in_array($encryption_algorithms[$i], $this->encryption_algorithms_client_to_server); $i++) {
}
if ($i == count($encryption_algorithms)) {
user_error('No compatible client to server encryption algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$encrypt = $encryption_algorithms[$i];
switch ($encrypt) {
case '3des-cbc':
case '3des-ctr':
$encryptKeyLength = 24;
break;
case 'aes256-cbc':
case 'aes256-ctr':
case 'twofish-cbc':
case 'twofish256-cbc':
case 'twofish256-ctr':
$encryptKeyLength = 32;
break;
case 'aes192-cbc':
case 'aes192-ctr':
case 'twofish192-cbc':
case 'twofish192-ctr':
$encryptKeyLength = 24;
break;
case 'aes128-cbc':
case 'aes128-ctr':
case 'twofish128-cbc':
case 'twofish128-ctr':
case 'blowfish-cbc':
case 'blowfish-ctr':
$encryptKeyLength = 16;
break;
case 'arcfour':
case 'arcfour128':
$encryptKeyLength = 16;
break;
case 'arcfour256':
$encryptKeyLength = 32;
break;
case 'none':
$encryptKeyLength = 0;
}
$keyLength = $decryptKeyLength > $encryptKeyLength ? $decryptKeyLength : $encryptKeyLength;
// through diffie-hellman key exchange a symmetric key is obtained
for ($i = 0; $i < count($kex_algorithms) && !in_array($kex_algorithms[$i], $this->kex_algorithms); $i++) {
}
if ($i == count($kex_algorithms)) {
user_error('No compatible key exchange algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
switch ($kex_algorithms[$i]) {
// see http://tools.ietf.org/html/rfc2409#section-6.2 and
// http://tools.ietf.org/html/rfc2412, appendex E
case 'diffie-hellman-group1-sha1':
$prime = 'FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74' . '020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F1437' . '4FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED' . 'EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF';
break;
// see http://tools.ietf.org/html/rfc3526#section-3
// see http://tools.ietf.org/html/rfc3526#section-3
case 'diffie-hellman-group14-sha1':
$prime = 'FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74' . '020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F1437' . '4FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED' . 'EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3DC2007CB8A163BF05' . '98DA48361C55D39A69163FA8FD24CF5F83655D23DCA3AD961C62F356208552BB' . '9ED529077096966D670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B' . 'E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF695581718' . '3995497CEA956AE515D2261898FA051015728E5A8AACAA68FFFFFFFFFFFFFFFF';
break;
}
// For both diffie-hellman-group1-sha1 and diffie-hellman-group14-sha1
// the generator field element is 2 (decimal) and the hash function is sha1.
$g = new Math_BigInteger(2);
$prime = new Math_BigInteger($prime, 16);
$kexHash = new Crypt_Hash('sha1');
//$q = $p->bitwise_rightShift(1);
/* To increase the speed of the key exchange, both client and server may
reduce the size of their private exponents. It should be at least
twice as long as the key material that is generated from the shared
secret. For more details, see the paper by van Oorschot and Wiener
[VAN-OORSCHOT].
-- http://tools.ietf.org/html/rfc4419#section-6.2 */
$one = new Math_BigInteger(1);
$keyLength = min($keyLength, $kexHash->getLength());
$max = $one->bitwise_leftShift(16 * $keyLength);
// 2 * 8 * $keyLength
$max = $max->subtract($one);
$x = $one->random($one, $max);
$e = $g->modPow($x, $prime);
$eBytes = $e->toBytes(true);
$data = pack('CNa*', NET_SSH2_MSG_KEXDH_INIT, strlen($eBytes), $eBytes);
if (!$this->_send_binary_packet($data)) {
user_error('Connection closed by server');
return false;
}
$response = $this->_get_binary_packet();
if ($response === false) {
user_error('Connection closed by server');
return false;
}
extract(unpack('Ctype', $this->_string_shift($response, 1)));
if ($type != NET_SSH2_MSG_KEXDH_REPLY) {
user_error('Expected SSH_MSG_KEXDH_REPLY');
return false;
}
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->server_public_host_key = $server_public_host_key = $this->_string_shift($response, $temp['length']);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$public_key_format = $this->_string_shift($server_public_host_key, $temp['length']);
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$fBytes = $this->_string_shift($response, $temp['length']);
$f = new Math_BigInteger($fBytes, -256);
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->signature = $this->_string_shift($response, $temp['length']);
$temp = unpack('Nlength', $this->_string_shift($this->signature, 4));
$this->signature_format = $this->_string_shift($this->signature, $temp['length']);
$key = $f->modPow($x, $prime);
$keyBytes = $key->toBytes(true);
$this->exchange_hash = pack('Na*Na*Na*Na*Na*Na*Na*Na*', strlen($this->identifier), $this->identifier, strlen($this->server_identifier), $this->server_identifier, strlen($kexinit_payload_client), $kexinit_payload_client, strlen($kexinit_payload_server), $kexinit_payload_server, strlen($this->server_public_host_key), $this->server_public_host_key, strlen($eBytes), $eBytes, strlen($fBytes), $fBytes, strlen($keyBytes), $keyBytes);
$this->exchange_hash = $kexHash->hash($this->exchange_hash);
if ($this->session_id === false) {
$this->session_id = $this->exchange_hash;
}
for ($i = 0; $i < count($server_host_key_algorithms) && !in_array($server_host_key_algorithms[$i], $this->server_host_key_algorithms); $i++) {
}
if ($i == count($server_host_key_algorithms)) {
user_error('No compatible server host key algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
if ($public_key_format != $server_host_key_algorithms[$i] || $this->signature_format != $server_host_key_algorithms[$i]) {
user_error('Server Host Key Algorithm Mismatch');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$packet = pack('C', NET_SSH2_MSG_NEWKEYS);
if (!$this->_send_binary_packet($packet)) {
return false;
}
$response = $this->_get_binary_packet();
if ($response === false) {
user_error('Connection closed by server');
return false;
}
extract(unpack('Ctype', $this->_string_shift($response, 1)));
if ($type != NET_SSH2_MSG_NEWKEYS) {
user_error('Expected SSH_MSG_NEWKEYS');
return false;
}
switch ($encrypt) {
case '3des-cbc':
if (!class_exists('Crypt_TripleDES')) {
include_once 'Crypt/TripleDES.php';
}
$this->encrypt = new Crypt_TripleDES();
// $this->encrypt_block_size = 64 / 8 == the default
break;
case '3des-ctr':
if (!class_exists('Crypt_TripleDES')) {
include_once 'Crypt/TripleDES.php';
}
$this->encrypt = new Crypt_TripleDES(CRYPT_DES_MODE_CTR);
// $this->encrypt_block_size = 64 / 8 == the default
break;
case 'aes256-cbc':
case 'aes192-cbc':
case 'aes128-cbc':
if (!class_exists('Crypt_Rijndael')) {
include_once 'Crypt/Rijndael.php';
}
$this->encrypt = new Crypt_Rijndael();
$this->encrypt_block_size = 16;
// eg. 128 / 8
break;
case 'aes256-ctr':
case 'aes192-ctr':
case 'aes128-ctr':
if (!class_exists('Crypt_Rijndael')) {
include_once 'Crypt/Rijndael.php';
}
$this->encrypt = new Crypt_Rijndael(CRYPT_RIJNDAEL_MODE_CTR);
$this->encrypt_block_size = 16;
// eg. 128 / 8
break;
case 'blowfish-cbc':
if (!class_exists('Crypt_Blowfish')) {
include_once 'Crypt/Blowfish.php';
}
$this->encrypt = new Crypt_Blowfish();
$this->encrypt_block_size = 8;
break;
case 'blowfish-ctr':
if (!class_exists('Crypt_Blowfish')) {
include_once 'Crypt/Blowfish.php';
}
$this->encrypt = new Crypt_Blowfish(CRYPT_BLOWFISH_MODE_CTR);
$this->encrypt_block_size = 8;
break;
case 'twofish128-cbc':
case 'twofish192-cbc':
case 'twofish256-cbc':
case 'twofish-cbc':
if (!class_exists('Crypt_Twofish')) {
include_once 'Crypt/Twofish.php';
}
$this->encrypt = new Crypt_Twofish();
$this->encrypt_block_size = 16;
break;
case 'twofish128-ctr':
case 'twofish192-ctr':
case 'twofish256-ctr':
if (!class_exists('Crypt_Twofish')) {
include_once 'Crypt/Twofish.php';
}
$this->encrypt = new Crypt_Twofish(CRYPT_TWOFISH_MODE_CTR);
$this->encrypt_block_size = 16;
break;
case 'arcfour':
case 'arcfour128':
case 'arcfour256':
if (!class_exists('Crypt_RC4')) {
include_once 'Crypt/RC4.php';
}
$this->encrypt = new Crypt_RC4();
break;
case 'none':
//$this->encrypt = new Crypt_Null();
}
switch ($decrypt) {
case '3des-cbc':
if (!class_exists('Crypt_TripleDES')) {
include_once 'Crypt/TripleDES.php';
}
$this->decrypt = new Crypt_TripleDES();
break;
case '3des-ctr':
if (!class_exists('Crypt_TripleDES')) {
include_once 'Crypt/TripleDES.php';
}
$this->decrypt = new Crypt_TripleDES(CRYPT_DES_MODE_CTR);
break;
case 'aes256-cbc':
case 'aes192-cbc':
case 'aes128-cbc':
if (!class_exists('Crypt_Rijndael')) {
include_once 'Crypt/Rijndael.php';
}
$this->decrypt = new Crypt_Rijndael();
$this->decrypt_block_size = 16;
break;
case 'aes256-ctr':
case 'aes192-ctr':
case 'aes128-ctr':
if (!class_exists('Crypt_Rijndael')) {
include_once 'Crypt/Rijndael.php';
}
$this->decrypt = new Crypt_Rijndael(CRYPT_RIJNDAEL_MODE_CTR);
$this->decrypt_block_size = 16;
break;
case 'blowfish-cbc':
if (!class_exists('Crypt_Blowfish')) {
include_once 'Crypt/Blowfish.php';
}
$this->decrypt = new Crypt_Blowfish();
$this->decrypt_block_size = 8;
break;
case 'blowfish-ctr':
if (!class_exists('Crypt_Blowfish')) {
include_once 'Crypt/Blowfish.php';
}
$this->decrypt = new Crypt_Blowfish(CRYPT_BLOWFISH_MODE_CTR);
$this->decrypt_block_size = 8;
break;
case 'twofish128-cbc':
case 'twofish192-cbc':
case 'twofish256-cbc':
case 'twofish-cbc':
if (!class_exists('Crypt_Twofish')) {
include_once 'Crypt/Twofish.php';
}
$this->decrypt = new Crypt_Twofish();
$this->decrypt_block_size = 16;
break;
case 'twofish128-ctr':
case 'twofish192-ctr':
case 'twofish256-ctr':
if (!class_exists('Crypt_Twofish')) {
include_once 'Crypt/Twofish.php';
}
$this->decrypt = new Crypt_Twofish(CRYPT_TWOFISH_MODE_CTR);
$this->decrypt_block_size = 16;
break;
case 'arcfour':
case 'arcfour128':
case 'arcfour256':
if (!class_exists('Crypt_RC4')) {
include_once 'Crypt/RC4.php';
}
$this->decrypt = new Crypt_RC4();
break;
case 'none':
//$this->decrypt = new Crypt_Null();
}
$keyBytes = pack('Na*', strlen($keyBytes), $keyBytes);
if ($this->encrypt) {
$this->encrypt->enableContinuousBuffer();
$this->encrypt->disablePadding();
$iv = $kexHash->hash($keyBytes . $this->exchange_hash . 'A' . $this->session_id);
while ($this->encrypt_block_size > strlen($iv)) {
$iv .= $kexHash->hash($keyBytes . $this->exchange_hash . $iv);
}
$this->encrypt->setIV(substr($iv, 0, $this->encrypt_block_size));
$key = $kexHash->hash($keyBytes . $this->exchange_hash . 'C' . $this->session_id);
while ($encryptKeyLength > strlen($key)) {
$key .= $kexHash->hash($keyBytes . $this->exchange_hash . $key);
}
$this->encrypt->setKey(substr($key, 0, $encryptKeyLength));
}
if ($this->decrypt) {
$this->decrypt->enableContinuousBuffer();
$this->decrypt->disablePadding();
$iv = $kexHash->hash($keyBytes . $this->exchange_hash . 'B' . $this->session_id);
while ($this->decrypt_block_size > strlen($iv)) {
$iv .= $kexHash->hash($keyBytes . $this->exchange_hash . $iv);
}
$this->decrypt->setIV(substr($iv, 0, $this->decrypt_block_size));
$key = $kexHash->hash($keyBytes . $this->exchange_hash . 'D' . $this->session_id);
while ($decryptKeyLength > strlen($key)) {
$key .= $kexHash->hash($keyBytes . $this->exchange_hash . $key);
}
$this->decrypt->setKey(substr($key, 0, $decryptKeyLength));
}
/* The "arcfour128" algorithm is the RC4 cipher, as described in
[SCHNEIER], using a 128-bit key. The first 1536 bytes of keystream
generated by the cipher MUST be discarded, and the first byte of the
first encrypted packet MUST be encrypted using the 1537th byte of
keystream.
-- http://tools.ietf.org/html/rfc4345#section-4 */
if ($encrypt == 'arcfour128' || $encrypt == 'arcfour256') {
$this->encrypt->encrypt(str_repeat("", 1536));
}
if ($decrypt == 'arcfour128' || $decrypt == 'arcfour256') {
$this->decrypt->decrypt(str_repeat("", 1536));
}
for ($i = 0; $i < count($mac_algorithms) && !in_array($mac_algorithms[$i], $this->mac_algorithms_client_to_server); $i++) {
}
if ($i == count($mac_algorithms)) {
user_error('No compatible client to server message authentication algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$createKeyLength = 0;
// ie. $mac_algorithms[$i] == 'none'
switch ($mac_algorithms[$i]) {
case 'hmac-sha1':
$this->hmac_create = new Crypt_Hash('sha1');
$createKeyLength = 20;
break;
case 'hmac-sha1-96':
$this->hmac_create = new Crypt_Hash('sha1-96');
$createKeyLength = 20;
break;
case 'hmac-md5':
$this->hmac_create = new Crypt_Hash('md5');
$createKeyLength = 16;
break;
case 'hmac-md5-96':
$this->hmac_create = new Crypt_Hash('md5-96');
$createKeyLength = 16;
}
for ($i = 0; $i < count($mac_algorithms) && !in_array($mac_algorithms[$i], $this->mac_algorithms_server_to_client); $i++) {
}
if ($i == count($mac_algorithms)) {
user_error('No compatible server to client message authentication algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$checkKeyLength = 0;
$this->hmac_size = 0;
switch ($mac_algorithms[$i]) {
case 'hmac-sha1':
$this->hmac_check = new Crypt_Hash('sha1');
$checkKeyLength = 20;
$this->hmac_size = 20;
break;
case 'hmac-sha1-96':
$this->hmac_check = new Crypt_Hash('sha1-96');
$checkKeyLength = 20;
$this->hmac_size = 12;
break;
case 'hmac-md5':
$this->hmac_check = new Crypt_Hash('md5');
$checkKeyLength = 16;
$this->hmac_size = 16;
break;
case 'hmac-md5-96':
$this->hmac_check = new Crypt_Hash('md5-96');
$checkKeyLength = 16;
$this->hmac_size = 12;
}
$key = $kexHash->hash($keyBytes . $this->exchange_hash . 'E' . $this->session_id);
while ($createKeyLength > strlen($key)) {
$key .= $kexHash->hash($keyBytes . $this->exchange_hash . $key);
}
$this->hmac_create->setKey(substr($key, 0, $createKeyLength));
$key = $kexHash->hash($keyBytes . $this->exchange_hash . 'F' . $this->session_id);
while ($checkKeyLength > strlen($key)) {
$key .= $kexHash->hash($keyBytes . $this->exchange_hash . $key);
}
$this->hmac_check->setKey(substr($key, 0, $checkKeyLength));
for ($i = 0; $i < count($compression_algorithms) && !in_array($compression_algorithms[$i], $this->compression_algorithms_server_to_client); $i++) {
}
if ($i == count($compression_algorithms)) {
user_error('No compatible server to client compression algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$this->decompress = $compression_algorithms[$i] == 'zlib';
for ($i = 0; $i < count($compression_algorithms) && !in_array($compression_algorithms[$i], $this->compression_algorithms_client_to_server); $i++) {
}
if ($i == count($compression_algorithms)) {
user_error('No compatible client to server compression algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$this->compress = $compression_algorithms[$i] == 'zlib';
return true;
}
/**
* Default Constructor.
*
* Connects to an SSHv1 server
*
* @param String $host
* @param optional Integer $port
* @param optional Integer $timeout
* @param optional Integer $cipher
* @return Net_SSH1
* @access public
*/
function Net_SSH1($host, $port = 22, $timeout = 10, $cipher = NET_SSH1_CIPHER_3DES)
{
if (!class_exists('Math_BigInteger')) {
include_once EASYWIDIR . '/third_party/phpseclib/Math/BigInteger.php';
}
// Include Crypt_Random
// the class_exists() will only be called if the crypt_random_string function hasn't been defined and
// will trigger a call to __autoload() if you're wanting to auto-load classes
// call function_exists() a second time to stop the include_once from being called outside
// of the auto loader
if (!function_exists('crypt_random_string') && !class_exists('Crypt_Random') && !function_exists('crypt_random_string')) {
include_once EASYWIDIR . '/third_party/phpseclib/Crypt/Random.php';
}
$this->protocol_flags = array(1 => 'NET_SSH1_MSG_DISCONNECT', 2 => 'NET_SSH1_SMSG_PUBLIC_KEY', 3 => 'NET_SSH1_CMSG_SESSION_KEY', 4 => 'NET_SSH1_CMSG_USER', 9 => 'NET_SSH1_CMSG_AUTH_PASSWORD', 10 => 'NET_SSH1_CMSG_REQUEST_PTY', 12 => 'NET_SSH1_CMSG_EXEC_SHELL', 13 => 'NET_SSH1_CMSG_EXEC_CMD', 14 => 'NET_SSH1_SMSG_SUCCESS', 15 => 'NET_SSH1_SMSG_FAILURE', 16 => 'NET_SSH1_CMSG_STDIN_DATA', 17 => 'NET_SSH1_SMSG_STDOUT_DATA', 18 => 'NET_SSH1_SMSG_STDERR_DATA', 19 => 'NET_SSH1_CMSG_EOF', 20 => 'NET_SSH1_SMSG_EXITSTATUS', 33 => 'NET_SSH1_CMSG_EXIT_CONFIRMATION');
$this->_define_array($this->protocol_flags);
$this->fsock = @fsockopen($host, $port, $errno, $errstr, $timeout);
if (!$this->fsock) {
user_error(rtrim("Cannot connect to {$host}. Error {$errno}. {$errstr}"));
return;
}
$this->server_identification = $init_line = fgets($this->fsock, 255);
if (defined('NET_SSH1_LOGGING')) {
$this->_append_log('<-', $this->server_identification);
$this->_append_log('->', $this->identifier . "\r\n");
}
if (!preg_match('#SSH-([0-9\\.]+)-(.+)#', $init_line, $parts)) {
user_error('Can only connect to SSH servers');
return;
}
if ($parts[1][0] != 1) {
user_error("Cannot connect to SSH {$parts['1']} servers");
return;
}
fputs($this->fsock, $this->identifier . "\r\n");
$response = $this->_get_binary_packet();
if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_PUBLIC_KEY) {
user_error('Expected SSH_SMSG_PUBLIC_KEY');
return;
}
$anti_spoofing_cookie = $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 8);
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$server_key_public_exponent = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->server_key_public_exponent = $server_key_public_exponent;
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$server_key_public_modulus = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->server_key_public_modulus = $server_key_public_modulus;
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$host_key_public_exponent = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->host_key_public_exponent = $host_key_public_exponent;
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$host_key_public_modulus = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->host_key_public_modulus = $host_key_public_modulus;
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
// get a list of the supported ciphers
extract(unpack('Nsupported_ciphers_mask', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4)));
foreach ($this->supported_ciphers as $mask => $name) {
if (($supported_ciphers_mask & 1 << $mask) == 0) {
unset($this->supported_ciphers[$mask]);
}
}
// get a list of the supported authentications
extract(unpack('Nsupported_authentications_mask', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4)));
foreach ($this->supported_authentications as $mask => $name) {
if (($supported_authentications_mask & 1 << $mask) == 0) {
unset($this->supported_authentications[$mask]);
}
}
$session_id = pack('H*', md5($host_key_public_modulus->toBytes() . $server_key_public_modulus->toBytes() . $anti_spoofing_cookie));
$session_key = crypt_random_string(32);
$double_encrypted_session_key = $session_key ^ str_pad($session_id, 32, chr(0));
if ($server_key_public_modulus->compare($host_key_public_modulus) < 0) {
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($server_key_public_exponent, $server_key_public_modulus));
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($host_key_public_exponent, $host_key_public_modulus));
} else {
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($host_key_public_exponent, $host_key_public_modulus));
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($server_key_public_exponent, $server_key_public_modulus));
}
$cipher = isset($this->supported_ciphers[$cipher]) ? $cipher : NET_SSH1_CIPHER_3DES;
$data = pack('C2a*na*N', NET_SSH1_CMSG_SESSION_KEY, $cipher, $anti_spoofing_cookie, 8 * strlen($double_encrypted_session_key), $double_encrypted_session_key, 0);
if (!$this->_send_binary_packet($data)) {
user_error('Error sending SSH_CMSG_SESSION_KEY');
return;
}
switch ($cipher) {
//case NET_SSH1_CIPHER_NONE:
// $this->crypto = new Crypt_Null();
// break;
case NET_SSH1_CIPHER_DES:
if (!class_exists('Crypt_DES')) {
include_once EASYWIDIR . '/third_party/phpseclib/Crypt/DES.php';
}
$this->crypto = new Crypt_DES();
$this->crypto->disablePadding();
$this->crypto->enableContinuousBuffer();
$this->crypto->setKey(substr($session_key, 0, 8));
break;
case NET_SSH1_CIPHER_3DES:
if (!class_exists('Crypt_TripleDES')) {
include_once EASYWIDIR . '/third_party/phpseclib/Crypt/TripleDES.php';
}
$this->crypto = new Crypt_TripleDES(CRYPT_DES_MODE_3CBC);
$this->crypto->disablePadding();
$this->crypto->enableContinuousBuffer();
$this->crypto->setKey(substr($session_key, 0, 24));
break;
//case NET_SSH1_CIPHER_RC4:
// if (!class_exists('Crypt_RC4')) {
// include_once('Crypt/RC4.php');
// }
// $this->crypto = new Crypt_RC4();
// $this->crypto->enableContinuousBuffer();
// $this->crypto->setKey(substr($session_key, 0, 16));
// break;
}
$response = $this->_get_binary_packet();
if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_SUCCESS) {
user_error('Expected SSH_SMSG_SUCCESS');
return;
}
$this->bitmap = NET_SSH1_MASK_CONSTRUCTOR;
}
/**
* Connect to an SSHv1 server
*
* @return Boolean
* @access private
*/
function _connect()
{
$this->fsock = @fsockopen($this->host, $this->port, $errno, $errstr, $this->connectionTimeout);
if (!$this->fsock) {
user_error(rtrim("Cannot connect to {$this->host}:{$this->port}. Error {$errno}. {$errstr}"));
return false;
}
$this->server_identification = $init_line = fgets($this->fsock, 255);
if (defined('NET_SSH1_LOGGING')) {
$this->_append_log('<-', $this->server_identification);
$this->_append_log('->', $this->identifier . "\r\n");
}
if (!preg_match('#SSH-([0-9\\.]+)-(.+)#', $init_line, $parts)) {
user_error('Can only connect to SSH servers');
return false;
}
if ($parts[1][0] != 1) {
user_error("Cannot connect to SSH {$parts['1']} servers");
return false;
}
fputs($this->fsock, $this->identifier . "\r\n");
$response = $this->_get_binary_packet();
if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_PUBLIC_KEY) {
user_error('Expected SSH_SMSG_PUBLIC_KEY');
return false;
}
$anti_spoofing_cookie = $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 8);
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$server_key_public_exponent = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->server_key_public_exponent = $server_key_public_exponent;
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$server_key_public_modulus = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->server_key_public_modulus = $server_key_public_modulus;
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$host_key_public_exponent = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->host_key_public_exponent = $host_key_public_exponent;
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$host_key_public_modulus = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->host_key_public_modulus = $host_key_public_modulus;
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
// get a list of the supported ciphers
extract(unpack('Nsupported_ciphers_mask', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4)));
foreach ($this->supported_ciphers as $mask => $name) {
if (($supported_ciphers_mask & 1 << $mask) == 0) {
unset($this->supported_ciphers[$mask]);
}
}
// get a list of the supported authentications
extract(unpack('Nsupported_authentications_mask', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4)));
foreach ($this->supported_authentications as $mask => $name) {
if (($supported_authentications_mask & 1 << $mask) == 0) {
unset($this->supported_authentications[$mask]);
}
}
$session_id = pack('H*', md5($host_key_public_modulus->toBytes() . $server_key_public_modulus->toBytes() . $anti_spoofing_cookie));
$session_key = crypt_random_string(32);
$double_encrypted_session_key = $session_key ^ str_pad($session_id, 32, chr(0));
if ($server_key_public_modulus->compare($host_key_public_modulus) < 0) {
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($server_key_public_exponent, $server_key_public_modulus));
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($host_key_public_exponent, $host_key_public_modulus));
} else {
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($host_key_public_exponent, $host_key_public_modulus));
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($server_key_public_exponent, $server_key_public_modulus));
}
$cipher = isset($this->supported_ciphers[$this->cipher]) ? $this->cipher : NET_SSH1_CIPHER_3DES;
$data = pack('C2a*na*N', NET_SSH1_CMSG_SESSION_KEY, $cipher, $anti_spoofing_cookie, 8 * strlen($double_encrypted_session_key), $double_encrypted_session_key, 0);
if (!$this->_send_binary_packet($data)) {
user_error('Error sending SSH_CMSG_SESSION_KEY');
return false;
}
switch ($cipher) {
//case NET_SSH1_CIPHER_NONE:
// $this->crypto = new Crypt_Null();
// break;
case NET_SSH1_CIPHER_DES:
if (!class_exists('Crypt_DES')) {
include_once 'Crypt/DES.php';
}
$this->crypto = new Crypt_DES();
$this->crypto->disablePadding();
$this->crypto->enableContinuousBuffer();
$this->crypto->setKey(substr($session_key, 0, 8));
break;
case NET_SSH1_CIPHER_3DES:
if (!class_exists('Crypt_TripleDES')) {
include_once 'Crypt/TripleDES.php';
}
$this->crypto = new Crypt_TripleDES(CRYPT_DES_MODE_3CBC);
$this->crypto->disablePadding();
$this->crypto->enableContinuousBuffer();
$this->crypto->setKey(substr($session_key, 0, 24));
break;
//case NET_SSH1_CIPHER_RC4:
// if (!class_exists('Crypt_RC4')) {
// include_once 'Crypt/RC4.php';
// }
// $this->crypto = new Crypt_RC4();
// $this->crypto->enableContinuousBuffer();
// $this->crypto->setKey(substr($session_key, 0, 16));
// break;
}
$response = $this->_get_binary_packet();
if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_SUCCESS) {
user_error('Expected SSH_SMSG_SUCCESS');
return false;
}
$this->bitmap = NET_SSH1_MASK_CONNECTED;
return true;
}
/**
* Default Constructor.
*
* Connects to an SSHv1 server
*
* @param String $host
* @param optional Integer $port
* @param optional Integer $timeout
* @param optional Integer $cipher
* @return Net_SSH1
* @access public
*/
function Net_SSH1($host, $port = 22, $timeout = 10, $cipher = NET_SSH1_CIPHER_3DES)
{
$this->fsock = @fsockopen($host, $port, $errno, $errstr, $timeout);
if (!$this->fsock) {
user_error(rtrim("Cannot connect to {$host}. Error {$errno}. {$errstr}"), E_USER_NOTICE);
return;
}
$this->server_identification = $init_line = fgets($this->fsock, 255);
if (!preg_match('#SSH-([0-9\\.]+)-(.+)#', $init_line, $parts)) {
user_error('Can only connect to SSH servers', E_USER_NOTICE);
return;
}
if ($parts[1][0] != 1) {
user_error("Cannot connect to SSH {$parts['1']} servers", E_USER_NOTICE);
return;
}
fputs($this->fsock, $this->identifier . "\r\n");
$response = $this->_get_binary_packet();
if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_PUBLIC_KEY) {
user_error('Expected SSH_SMSG_PUBLIC_KEY', E_USER_NOTICE);
return;
}
$anti_spoofing_cookie = $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 8);
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$server_key_public_exponent = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->server_key_public_exponent = $server_key_public_exponent;
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$server_key_public_modulus = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->server_key_public_modulus = $server_key_public_modulus;
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$host_key_public_exponent = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->host_key_public_exponent = $host_key_public_exponent;
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$host_key_public_modulus = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->host_key_public_modulus = $host_key_public_modulus;
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
// get a list of the supported ciphers
list(, $supported_ciphers_mask) = unpack('N', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4));
foreach ($this->supported_ciphers as $mask => $name) {
if (($supported_ciphers_mask & 1 << $mask) == 0) {
unset($this->supported_ciphers[$mask]);
}
}
// get a list of the supported authentications
list(, $supported_authentications_mask) = unpack('N', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4));
foreach ($this->supported_authentications as $mask => $name) {
if (($supported_authentications_mask & 1 << $mask) == 0) {
unset($this->supported_authentications[$mask]);
}
}
$session_id = pack('H*', md5($host_key_public_modulus->toBytes() . $server_key_public_modulus->toBytes() . $anti_spoofing_cookie));
$session_key = '';
for ($i = 0; $i < 32; $i++) {
$session_key .= chr(crypt_random(0, 255));
}
$double_encrypted_session_key = $session_key ^ str_pad($session_id, 32, chr(0));
if ($server_key_public_modulus->compare($host_key_public_modulus) < 0) {
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($server_key_public_exponent, $server_key_public_modulus));
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($host_key_public_exponent, $host_key_public_modulus));
} else {
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($host_key_public_exponent, $host_key_public_modulus));
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($server_key_public_exponent, $server_key_public_modulus));
}
$cipher = isset($this->supported_ciphers[$cipher]) ? $cipher : NET_SSH1_CIPHER_3DES;
$data = pack('C2a*na*N', NET_SSH1_CMSG_SESSION_KEY, $cipher, $anti_spoofing_cookie, 8 * strlen($double_encrypted_session_key), $double_encrypted_session_key, 0);
if (!$this->_send_binary_packet($data)) {
user_error('Error sending SSH_CMSG_SESSION_KEY', E_USER_NOTICE);
return;
}
switch ($cipher) {
//case NET_SSH1_CIPHER_NONE:
// $this->crypto = new Crypt_Null();
// break;
case NET_SSH1_CIPHER_DES:
$this->crypto = new Crypt_DES();
$this->crypto->disablePadding();
$this->crypto->enableContinuousBuffer();
$this->crypto->setKey(substr($session_key, 0, 8));
break;
case NET_SSH1_CIPHER_3DES:
$this->crypto = new Crypt_TripleDES(CRYPT_DES_MODE_3CBC);
$this->crypto->disablePadding();
$this->crypto->enableContinuousBuffer();
$this->crypto->setKey(substr($session_key, 0, 24));
break;
//case NET_SSH1_CIPHER_RC4:
// $this->crypto = new Crypt_RC4();
// $this->crypto->enableContinuousBuffer();
// $this->crypto->setKey(substr($session_key, 0, 16));
// break;
}
$response = $this->_get_binary_packet();
if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_SUCCESS) {
user_error('Expected SSH_SMSG_SUCCESS', E_USER_NOTICE);
return;
}
$this->bitmap = NET_SSH1_MASK_CONSTRUCTOR;
}
/**
* Key Exchange
*
* @param String $kexinit_payload_server
* @access private
*/
function _key_exchange($kexinit_payload_server)
{
static $kex_algorithms = array('diffie-hellman-group1-sha1', 'diffie-hellman-group14-sha1');
static $server_host_key_algorithms = array('ssh-rsa', 'ssh-dss');
static $encryption_algorithms = array('arcfour', 'aes128-cbc', 'aes192-cbc', 'aes256-cbc', '3des-cbc', 'none');
static $mac_algorithms = array('hmac-sha1-96', 'hmac-sha1', 'hmac-md5-96', 'hmac-md5', 'none');
static $compression_algorithms = array('none');
static $str_kex_algorithms, $str_server_host_key_algorithms, $encryption_algorithms_server_to_client, $mac_algorithms_server_to_client, $compression_algorithms_server_to_client, $encryption_algorithms_client_to_server, $mac_algorithms_client_to_server, $compression_algorithms_client_to_server;
if (empty($str_kex_algorithms)) {
$str_kex_algorithms = implode(',', $kex_algorithms);
$str_server_host_key_algorithms = implode(',', $server_host_key_algorithms);
$encryption_algorithms_server_to_client = $encryption_algorithms_client_to_server = implode(',', $encryption_algorithms);
$mac_algorithms_server_to_client = $mac_algorithms_client_to_server = implode(',', $mac_algorithms);
$compression_algorithms_server_to_client = $compression_algorithms_client_to_server = implode(',', $compression_algorithms);
}
$client_cookie = '';
for ($i = 0; $i < 16; $i++) {
$client_cookie .= chr(crypt_random(0, 255));
}
$response = $kexinit_payload_server;
$this->_string_shift($response, 1);
// skip past the message number (it should be SSH_MSG_KEXINIT)
$server_cookie = $this->_string_shift($response, 16);
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->kex_algorithms = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->server_host_key_algorithms = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->encryption_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->encryption_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->mac_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->mac_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->compression_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->compression_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->languages_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->languages_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
extract(unpack('Cfirst_kex_packet_follows', $this->_string_shift($response, 1)));
$first_kex_packet_follows = $first_kex_packet_follows != 0;
// the sending of SSH2_MSG_KEXINIT could go in one of two places. this is the second place.
$kexinit_payload_client = pack('Ca*Na*Na*Na*Na*Na*Na*Na*Na*Na*Na*CN', NET_SSH2_MSG_KEXINIT, $client_cookie, strlen($str_kex_algorithms), $str_kex_algorithms, strlen($str_server_host_key_algorithms), $str_server_host_key_algorithms, strlen($encryption_algorithms_client_to_server), $encryption_algorithms_client_to_server, strlen($encryption_algorithms_server_to_client), $encryption_algorithms_server_to_client, strlen($mac_algorithms_client_to_server), $mac_algorithms_client_to_server, strlen($mac_algorithms_server_to_client), $mac_algorithms_server_to_client, strlen($compression_algorithms_client_to_server), $compression_algorithms_client_to_server, strlen($compression_algorithms_server_to_client), $compression_algorithms_server_to_client, 0, '', 0, '', 0, 0);
if (!$this->_send_binary_packet($kexinit_payload_client)) {
return false;
}
// here ends the second place.
// we need to decide upon the symmetric encryption algorithms before we do the diffie-hellman key exchange
for ($i = 0; $i < count($encryption_algorithms) && !in_array($encryption_algorithms[$i], $this->encryption_algorithms_server_to_client); $i++) {
}
if ($i == count($encryption_algorithms)) {
user_error('No compatible server to client encryption algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
// we don't initialize any crypto-objects, yet - we do that, later. for now, we need the lengths to make the
// diffie-hellman key exchange as fast as possible
$decrypt = $encryption_algorithms[$i];
switch ($decrypt) {
case '3des-cbc':
$decryptKeyLength = 24;
// eg. 192 / 8
break;
case 'aes256-cbc':
$decryptKeyLength = 32;
// eg. 256 / 8
break;
case 'aes192-cbc':
$decryptKeyLength = 24;
// eg. 192 / 8
break;
case 'aes128-cbc':
$decryptKeyLength = 16;
// eg. 128 / 8
break;
case 'arcfour':
$decryptKeyLength = 16;
// eg. 128 / 8
break;
case 'none':
$decryptKeyLength = 0;
}
for ($i = 0; $i < count($encryption_algorithms) && !in_array($encryption_algorithms[$i], $this->encryption_algorithms_client_to_server); $i++) {
}
if ($i == count($encryption_algorithms)) {
user_error('No compatible client to server encryption algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$encrypt = $encryption_algorithms[$i];
switch ($encrypt) {
case '3des-cbc':
$encryptKeyLength = 24;
break;
case 'aes256-cbc':
$encryptKeyLength = 32;
break;
case 'aes192-cbc':
$encryptKeyLength = 24;
break;
case 'aes128-cbc':
$encryptKeyLength = 16;
break;
case 'arcfour':
$encryptKeyLength = 16;
break;
case 'none':
$encryptKeyLength = 0;
}
$keyLength = $decryptKeyLength > $encryptKeyLength ? $decryptKeyLength : $encryptKeyLength;
// through diffie-hellman key exchange a symmetric key is obtained
for ($i = 0; $i < count($kex_algorithms) && !in_array($kex_algorithms[$i], $this->kex_algorithms); $i++) {
}
if ($i == count($kex_algorithms)) {
user_error('No compatible key exchange algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
switch ($kex_algorithms[$i]) {
// see http://tools.ietf.org/html/rfc2409#section-6.2 and
// http://tools.ietf.org/html/rfc2412, appendex E
case 'diffie-hellman-group1-sha1':
$p = pack('H256', 'FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74' . '020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F1437' . '4FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED' . 'EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF');
$keyLength = $keyLength < 160 ? $keyLength : 160;
$hash = 'sha1';
break;
// see http://tools.ietf.org/html/rfc3526#section-3
// see http://tools.ietf.org/html/rfc3526#section-3
case 'diffie-hellman-group14-sha1':
$p = pack('H512', 'FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74' . '020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F1437' . '4FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED' . 'EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3DC2007CB8A163BF05' . '98DA48361C55D39A69163FA8FD24CF5F83655D23DCA3AD961C62F356208552BB' . '9ED529077096966D670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B' . 'E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF695581718' . '3995497CEA956AE515D2261898FA051015728E5A8AACAA68FFFFFFFFFFFFFFFF');
$keyLength = $keyLength < 160 ? $keyLength : 160;
$hash = 'sha1';
}
$p = new Math_BigInteger($p, 256);
//$q = $p->bitwise_rightShift(1);
/* To increase the speed of the key exchange, both client and server may
reduce the size of their private exponents. It should be at least
twice as long as the key material that is generated from the shared
secret. For more details, see the paper by van Oorschot and Wiener
[VAN-OORSCHOT].
-- http://tools.ietf.org/html/rfc4419#section-6.2 */
$q = new Math_BigInteger(1);
$q = $q->bitwise_leftShift(2 * $keyLength);
$q = $q->subtract(new Math_BigInteger(1));
$g = new Math_BigInteger(2);
$x = new Math_BigInteger();
$x->setRandomGenerator('crypt_random');
$x = $x->random(new Math_BigInteger(1), $q);
$e = $g->modPow($x, $p);
$eBytes = $e->toBytes(true);
$data = pack('CNa*', NET_SSH2_MSG_KEXDH_INIT, strlen($eBytes), $eBytes);
if (!$this->_send_binary_packet($data)) {
user_error('Connection closed by server', E_USER_NOTICE);
return false;
}
$response = $this->_get_binary_packet();
if ($response === false) {
user_error('Connection closed by server', E_USER_NOTICE);
return false;
}
extract(unpack('Ctype', $this->_string_shift($response, 1)));
if ($type != NET_SSH2_MSG_KEXDH_REPLY) {
user_error('Expected SSH_MSG_KEXDH_REPLY', E_USER_NOTICE);
return false;
}
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->server_public_host_key = $server_public_host_key = $this->_string_shift($response, $temp['length']);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$public_key_format = $this->_string_shift($server_public_host_key, $temp['length']);
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$fBytes = $this->_string_shift($response, $temp['length']);
$f = new Math_BigInteger($fBytes, -256);
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$signature = $this->_string_shift($response, $temp['length']);
$temp = unpack('Nlength', $this->_string_shift($signature, 4));
$signature_format = $this->_string_shift($signature, $temp['length']);
$key = $f->modPow($x, $p);
$keyBytes = $key->toBytes(true);
$source = pack('Na*Na*Na*Na*Na*Na*Na*Na*', strlen($this->identifier), $this->identifier, strlen($this->server_identifier), $this->server_identifier, strlen($kexinit_payload_client), $kexinit_payload_client, strlen($kexinit_payload_server), $kexinit_payload_server, strlen($this->server_public_host_key), $this->server_public_host_key, strlen($eBytes), $eBytes, strlen($fBytes), $fBytes, strlen($keyBytes), $keyBytes);
$source = pack('H*', $hash($source));
if ($this->session_id === false) {
$this->session_id = $source;
}
// if you the server's assymetric key matches the one you have on file, then you should be able to decrypt the
// "signature" and get something that should equal the "exchange hash", as defined in the SSH-2 specs.
// here, we just check to see if the "signature" is good. you can verify whether or not the assymetric key is good,
// later, with the getServerHostKeyAlgorithm() function
for ($i = 0; $i < count($server_host_key_algorithms) && !in_array($server_host_key_algorithms[$i], $this->server_host_key_algorithms); $i++) {
}
if ($i == count($server_host_key_algorithms)) {
user_error('No compatible server host key algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
if ($public_key_format != $server_host_key_algorithms[$i] || $signature_format != $server_host_key_algorithms[$i]) {
user_error('Sever Host Key Algorithm Mismatch', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
switch ($server_host_key_algorithms[$i]) {
case 'ssh-dss':
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$p = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$q = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$g = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$y = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
/* The value for 'dss_signature_blob' is encoded as a string containing
r, followed by s (which are 160-bit integers, without lengths or
padding, unsigned, and in network byte order). */
$temp = unpack('Nlength', $this->_string_shift($signature, 4));
if ($temp['length'] != 40) {
user_error('Invalid signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$r = new Math_BigInteger($this->_string_shift($signature, 20), 256);
$s = new Math_BigInteger($this->_string_shift($signature, 20), 256);
if ($r->compare($q) >= 0 || $s->compare($q) >= 0) {
user_error('Invalid signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$w = $s->modInverse($q);
$u1 = $w->multiply(new Math_BigInteger(sha1($source), 16));
list(, $u1) = $u1->divide($q);
$u2 = $w->multiply($r);
list(, $u2) = $u2->divide($q);
$g = $g->modPow($u1, $p);
$y = $y->modPow($u2, $p);
$v = $g->multiply($y);
list(, $v) = $v->divide($p);
list(, $v) = $v->divide($q);
if (!$v->equals($r)) {
user_error('Invalid signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
}
break;
case 'ssh-rsa':
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$e = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$n = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$nLength = $temp['length'];
/*
$temp = unpack('Nlength', $this->_string_shift($signature, 4));
$signature = $this->_string_shift($signature, $temp['length']);
if (!class_exists('Crypt_RSA')) {
require_once('Crypt/RSA.php');
}
$rsa = new Crypt_RSA();
$rsa->setSignatureMode(CRYPT_RSA_SIGNATURE_PKCS1);
$rsa->loadKey(array('e' => $e, 'n' => $n), CRYPT_RSA_PUBLIC_FORMAT_RAW);
if (!$rsa->verify($source, $signature)) {
user_error('Bad server signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
}
*/
$temp = unpack('Nlength', $this->_string_shift($signature, 4));
$s = new Math_BigInteger($this->_string_shift($signature, $temp['length']), 256);
// validate an RSA signature per "8.2 RSASSA-PKCS1-v1_5", "5.2.2 RSAVP1", and "9.1 EMSA-PSS" in the
// following URL:
// ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-1/pkcs-1v2-1.pdf
// also, see SSHRSA.c (rsa2_verifysig) in PuTTy's source.
if ($s->compare(new Math_BigInteger()) < 0 || $s->compare($n->subtract(new Math_BigInteger(1))) > 0) {
user_error('Invalid signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$s = $s->modPow($e, $n);
$s = $s->toBytes();
$h = pack('N4H*', 0x302130, 0x906052b, 0xe03021a, 0x5000414, sha1($source));
$h = chr(0x1) . str_repeat(chr(0xff), $nLength - 3 - strlen($h)) . $h;
if ($s != $h) {
user_error('Bad server signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
}
}
$packet = pack('C', NET_SSH2_MSG_NEWKEYS);
if (!$this->_send_binary_packet($packet)) {
return false;
}
$response = $this->_get_binary_packet();
if ($response === false) {
user_error('Connection closed by server', E_USER_NOTICE);
return false;
}
extract(unpack('Ctype', $this->_string_shift($response, 1)));
if ($type != NET_SSH2_MSG_NEWKEYS) {
user_error('Expected SSH_MSG_NEWKEYS', E_USER_NOTICE);
return false;
}
switch ($encrypt) {
case '3des-cbc':
$this->encrypt = new Crypt_TripleDES();
// $this->encrypt_block_size = 64 / 8 == the default
break;
case 'aes256-cbc':
$this->encrypt = new Crypt_AES();
$this->encrypt_block_size = 16;
// eg. 128 / 8
break;
case 'aes192-cbc':
$this->encrypt = new Crypt_AES();
$this->encrypt_block_size = 16;
break;
case 'aes128-cbc':
$this->encrypt = new Crypt_AES();
$this->encrypt_block_size = 16;
break;
case 'arcfour':
$this->encrypt = new Crypt_RC4();
break;
case 'none':
//$this->encrypt = new Crypt_Null();
}
switch ($decrypt) {
case '3des-cbc':
$this->decrypt = new Crypt_TripleDES();
break;
case 'aes256-cbc':
$this->decrypt = new Crypt_AES();
$this->decrypt_block_size = 16;
break;
case 'aes192-cbc':
$this->decrypt = new Crypt_AES();
$this->decrypt_block_size = 16;
break;
case 'aes128-cbc':
$this->decrypt = new Crypt_AES();
$this->decrypt_block_size = 16;
break;
case 'arcfour':
$this->decrypt = new Crypt_RC4();
break;
case 'none':
//$this->decrypt = new Crypt_Null();
}
$keyBytes = pack('Na*', strlen($keyBytes), $keyBytes);
if ($this->encrypt) {
$this->encrypt->enableContinuousBuffer();
$this->encrypt->disablePadding();
$iv = pack('H*', $hash($keyBytes . $source . 'A' . $this->session_id));
while ($this->encrypt_block_size > strlen($iv)) {
$iv .= pack('H*', $hash($keyBytes . $source . $iv));
}
$this->encrypt->setIV(substr($iv, 0, $this->encrypt_block_size));
$key = pack('H*', $hash($keyBytes . $source . 'C' . $this->session_id));
while ($encryptKeyLength > strlen($key)) {
$key .= pack('H*', $hash($keyBytes . $source . $key));
}
$this->encrypt->setKey(substr($key, 0, $encryptKeyLength));
}
if ($this->decrypt) {
$this->decrypt->enableContinuousBuffer();
$this->decrypt->disablePadding();
$iv = pack('H*', $hash($keyBytes . $source . 'B' . $this->session_id));
while ($this->decrypt_block_size > strlen($iv)) {
$iv .= pack('H*', $hash($keyBytes . $source . $iv));
}
$this->decrypt->setIV(substr($iv, 0, $this->decrypt_block_size));
$key = pack('H*', $hash($keyBytes . $source . 'D' . $this->session_id));
while ($decryptKeyLength > strlen($key)) {
$key .= pack('H*', $hash($keyBytes . $source . $key));
}
$this->decrypt->setKey(substr($key, 0, $decryptKeyLength));
}
for ($i = 0; $i < count($mac_algorithms) && !in_array($mac_algorithms[$i], $this->mac_algorithms_client_to_server); $i++) {
}
if ($i == count($mac_algorithms)) {
user_error('No compatible client to server message authentication algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$createKeyLength = 0;
// ie. $mac_algorithms[$i] == 'none'
switch ($mac_algorithms[$i]) {
case 'hmac-sha1':
$this->hmac_create = new Crypt_Hash('sha1');
$createKeyLength = 20;
break;
case 'hmac-sha1-96':
$this->hmac_create = new Crypt_Hash('sha1-96');
$createKeyLength = 20;
break;
case 'hmac-md5':
$this->hmac_create = new Crypt_Hash('md5');
$createKeyLength = 16;
break;
case 'hmac-md5-96':
$this->hmac_create = new Crypt_Hash('md5-96');
$createKeyLength = 16;
}
for ($i = 0; $i < count($mac_algorithms) && !in_array($mac_algorithms[$i], $this->mac_algorithms_server_to_client); $i++) {
}
if ($i == count($mac_algorithms)) {
user_error('No compatible server to client message authentication algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$checkKeyLength = 0;
$this->hmac_size = 0;
switch ($mac_algorithms[$i]) {
case 'hmac-sha1':
$this->hmac_check = new Crypt_Hash('sha1');
$checkKeyLength = 20;
$this->hmac_size = 20;
break;
case 'hmac-sha1-96':
$this->hmac_check = new Crypt_Hash('sha1-96');
$checkKeyLength = 20;
$this->hmac_size = 12;
break;
case 'hmac-md5':
$this->hmac_check = new Crypt_Hash('md5');
$checkKeyLength = 16;
$this->hmac_size = 16;
break;
case 'hmac-md5-96':
$this->hmac_check = new Crypt_Hash('md5-96');
$checkKeyLength = 16;
$this->hmac_size = 12;
}
$key = pack('H*', $hash($keyBytes . $source . 'E' . $this->session_id));
while ($createKeyLength > strlen($key)) {
$key .= pack('H*', $hash($keyBytes . $source . $key));
}
$this->hmac_create->setKey(substr($key, 0, $createKeyLength));
$key = pack('H*', $hash($keyBytes . $source . 'F' . $this->session_id));
while ($checkKeyLength > strlen($key)) {
$key .= pack('H*', $hash($keyBytes . $source . $key));
}
$this->hmac_check->setKey(substr($key, 0, $checkKeyLength));
for ($i = 0; $i < count($compression_algorithms) && !in_array($compression_algorithms[$i], $this->compression_algorithms_server_to_client); $i++) {
}
if ($i == count($compression_algorithms)) {
user_error('No compatible server to client compression algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$this->decompress = $compression_algorithms[$i] == 'zlib';
for ($i = 0; $i < count($compression_algorithms) && !in_array($compression_algorithms[$i], $this->compression_algorithms_client_to_server); $i++) {
}
if ($i == count($compression_algorithms)) {
user_error('No compatible client to server compression algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$this->compress = $compression_algorithms[$i] == 'zlib';
return true;
}
/**
* Key Exchange
*
* @param String $kexinit_payload_server
* @access private
*/
function _key_exchange($kexinit_payload_server)
{
static $kex_algorithms = array('diffie-hellman-group1-sha1', 'diffie-hellman-group14-sha1');
static $server_host_key_algorithms = array('ssh-rsa', 'ssh-dss');
static $encryption_algorithms = array('arcfour', 'aes128-cbc', 'aes192-cbc', 'aes256-cbc', '3des-cbc', 'none');
static $mac_algorithms = array('hmac-sha1-96', 'hmac-sha1', 'hmac-md5-96', 'hmac-md5', 'none');
static $compression_algorithms = array('none');
static $str_kex_algorithms, $str_server_host_key_algorithms, $encryption_algorithms_server_to_client, $mac_algorithms_server_to_client, $compression_algorithms_server_to_client, $encryption_algorithms_client_to_server, $mac_algorithms_client_to_server, $compression_algorithms_client_to_server;
if (empty($str_kex_algorithms)) {
$str_kex_algorithms = implode(',', $kex_algorithms);
$str_server_host_key_algorithms = implode(',', $server_host_key_algorithms);
$encryption_algorithms_server_to_client = $encryption_algorithms_client_to_server = implode(',', $encryption_algorithms);
$mac_algorithms_server_to_client = $mac_algorithms_client_to_server = implode(',', $mac_algorithms);
$compression_algorithms_server_to_client = $compression_algorithms_client_to_server = implode(',', $compression_algorithms);
}
$client_cookie = '';
for ($i = 0; $i < 16; $i++) {
$client_cookie .= chr(crypt_random(0, 255));
}
$response = $kexinit_payload_server;
$this->_string_shift($response, 1);
// skip past the message number (it should be SSH_MSG_KEXINIT)
list(, $server_cookie) = unpack('a16', $this->_string_shift($response, 16));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->kex_algorithms = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->server_host_key_algorithms = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->encryption_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->encryption_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->mac_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->mac_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->compression_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->compression_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->languages_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->languages_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
list(, $first_kex_packet_follows) = unpack('C', $this->_string_shift($response, 1));
$first_kex_packet_follows = $first_kex_packet_follows != 0;
// the sending of SSH2_MSG_KEXINIT could go in one of two places. this is the second place.
$kexinit_payload_client = pack('Ca*Na*Na*Na*Na*Na*Na*Na*Na*Na*Na*CN', NET_SSH2_MSG_KEXINIT, $client_cookie, strlen($str_kex_algorithms), $str_kex_algorithms, strlen($str_server_host_key_algorithms), $str_server_host_key_algorithms, strlen($encryption_algorithms_client_to_server), $encryption_algorithms_client_to_server, strlen($encryption_algorithms_server_to_client), $encryption_algorithms_server_to_client, strlen($mac_algorithms_client_to_server), $mac_algorithms_client_to_server, strlen($mac_algorithms_server_to_client), $mac_algorithms_server_to_client, strlen($compression_algorithms_client_to_server), $compression_algorithms_client_to_server, strlen($compression_algorithms_server_to_client), $compression_algorithms_server_to_client, 0, '', 0, '', 0, 0);
if (!$this->_send_binary_packet($kexinit_payload_client)) {
return false;
}
// here ends the second place.
// we need to decide upon the symmetric encryption algorithms before we do the diffie-hellman key exchange
for ($i = 0; $i < count($encryption_algorithms) && !in_array($encryption_algorithms[$i], $this->encryption_algorithms_server_to_client); $i++) {
}
if ($i == count($encryption_algorithms)) {
user_error('No compatible server to client encryption algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
// we don't initialize any crypto-objects, yet - we do that, later. for now, we need the lengths to make the
// diffie-hellman key exchange as fast as possible
$decrypt = $encryption_algorithms[$i];
switch ($decrypt) {
case '3des-cbc':
$decryptKeyLength = 24;
// eg. 192 / 8
break;
case 'aes256-cbc':
$decryptKeyLength = 32;
// eg. 256 / 8
break;
case 'aes192-cbc':
$decryptKeyLength = 24;
// eg. 192 / 8
break;
case 'aes128-cbc':
$decryptKeyLength = 16;
// eg. 128 / 8
break;
case 'arcfour':
$decryptKeyLength = 16;
// eg. 128 / 8
break;
case 'none':
$decryptKeyLength = 0;
}
for ($i = 0; $i < count($encryption_algorithms) && !in_array($encryption_algorithms[$i], $this->encryption_algorithms_client_to_server); $i++) {
}
if ($i == count($encryption_algorithms)) {
user_error('No compatible client to server encryption algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$encrypt = $encryption_algorithms[$i];
switch ($encrypt) {
case '3des-cbc':
$encryptKeyLength = 24;
break;
case 'aes256-cbc':
$encryptKeyLength = 32;
break;
case 'aes192-cbc':
$encryptKeyLength = 24;
break;
case 'aes128-cbc':
$encryptKeyLength = 16;
break;
case 'arcfour':
$encryptKeyLength = 16;
break;
case 'none':
$encryptKeyLength = 0;
}
$keyLength = $decryptKeyLength > $encryptKeyLength ? $decryptKeyLength : $encryptKeyLength;
// through diffie-hellman key exchange a symmetric key is obtained
for ($i = 0; $i < count($kex_algorithms) && !in_array($kex_algorithms[$i], $this->kex_algorithms); $i++) {
}
if ($i == count($kex_algorithms)) {
user_error('No compatible key exchange algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
switch ($kex_algorithms[$i]) {
// see http://tools.ietf.org/html/rfc2409#section-6.2 and
// http://tools.ietf.org/html/rfc2412, appendex E
case 'diffie-hellman-group1-sha1':
$p = pack('N32', 4294967295.0, 4294967295.0, 3373259426.0, 0x2168c234, 3301335691.0, 2161908945.0, 0x29024e08, 2322058356.0, 0x20bbea6, 0x3b139b22, 0x514a0879, 0.0, 0.0, 3443147547.0, 0x302b0a6d, 4066317367.0, 0x4fe1356d, 0x6d51c245, 0.0, 0x625e7ec6, 0.0, 0.0, 0xbff5cb6, 0.0, 0.0, 0x5a899fa5, 0.0, 0x7c4b1fe6, 0x49286651, 0.0, 4294967295.0, 4294967295.0);
$keyLength = $keyLength < 160 ? $keyLength : 160;
$hash = 'sha1';
break;
// see http://tools.ietf.org/html/rfc3526#section-3
// see http://tools.ietf.org/html/rfc3526#section-3
case 'diffie-hellman-group14-sha1':
$p = pack('N64', 4294967295.0, 4294967295.0, 3373259426.0, 0x2168c234, 3301335691.0, 2161908945.0, 0x29024e08, 2322058356.0, 0x20bbea6, 0x3b139b22, 0x514a0879, 0.0, 0.0, 3443147547.0, 0x302b0a6d, 4066317367.0, 0x4fe1356d, 0x6d51c245, 0.0, 0x625e7ec6, 0.0, 0.0, 0xbff5cb6, 0.0, 0.0, 0x5a899fa5, 0.0, 0x7c4b1fe6, 0x49286651, 0.0, 3254811832.0, 2707668741.0, 2564442166.0, 0x1c55d39a, 0x69163fa8, 4247048031.0, 2204458275.0, 3701714326.0, 0x1c62f356, 0x208552bb, 0.0, 0x7096966d, 0x670c354e, 0x4abc9804, 4050938888.0, 3390579068.0, 0x32905e46, 0x2e36ce3b, 0.0, 0x180e8603, 2603058082.0, 0.0, 3049610736.0, 0x6f4c52c9, 0.0, 2505578264.0, 0x3995497c, 0.0, 0x15d22618, 2566522128.0, 0x15728e5a, 2326571624.0, 4294967295.0, 4294967295.0);
$keyLength = $keyLength < 160 ? $keyLength : 160;
$hash = 'sha1';
}
$p = new Math_BigInteger($p, 256);
//$q = $p->bitwise_rightShift(1);
/* To increase the speed of the key exchange, both client and server may
reduce the size of their private exponents. It should be at least
twice as long as the key material that is generated from the shared
secret. For more details, see the paper by van Oorschot and Wiener
[VAN-OORSCHOT].
-- http://tools.ietf.org/html/rfc4419#section-6.2 */
$q = new Math_BigInteger(1);
$q = $q->bitwise_leftShift(2 * $keyLength);
$q = $q->subtract(new Math_BigInteger(1));
$g = new Math_BigInteger(2);
$x = new Math_BigInteger();
$x = $x->random(new Math_BigInteger(1), $q, 'crypt_random');
$e = $g->modPow($x, $p);
$eBytes = $e->toBytes(true);
$data = pack('CNa*', NET_SSH2_MSG_KEXDH_INIT, strlen($eBytes), $eBytes);
if (!$this->_send_binary_packet($data)) {
user_error('Connection closed by server', E_USER_NOTICE);
return false;
}
$response = $this->_get_binary_packet();
if ($response === false) {
user_error('Connection closed by server', E_USER_NOTICE);
return false;
}
list(, $type) = unpack('C', $this->_string_shift($response, 1));
if ($type != NET_SSH2_MSG_KEXDH_REPLY) {
user_error('Expected SSH_MSG_KEXDH_REPLY', E_USER_NOTICE);
return false;
}
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->server_public_host_key = $server_public_host_key = $this->_string_shift($response, $temp['length']);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$public_key_format = $this->_string_shift($server_public_host_key, $temp['length']);
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$fBytes = $this->_string_shift($response, $temp['length']);
$f = new Math_BigInteger($fBytes, -256);
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$signature = $this->_string_shift($response, $temp['length']);
$temp = unpack('Nlength', $this->_string_shift($signature, 4));
$signature_format = $this->_string_shift($signature, $temp['length']);
$key = $f->modPow($x, $p);
$keyBytes = $key->toBytes(true);
$source = pack('Na*Na*Na*Na*Na*Na*Na*Na*', strlen($this->identifier), $this->identifier, strlen($this->server_identifier), $this->server_identifier, strlen($kexinit_payload_client), $kexinit_payload_client, strlen($kexinit_payload_server), $kexinit_payload_server, strlen($this->server_public_host_key), $this->server_public_host_key, strlen($eBytes), $eBytes, strlen($fBytes), $fBytes, strlen($keyBytes), $keyBytes);
$source = pack('H*', $hash($source));
if ($this->session_id === false) {
$this->session_id = $source;
}
// if you the server's assymetric key matches the one you have on file, then you should be able to decrypt the
// "signature" and get something that should equal the "exchange hash", as defined in the SSH-2 specs.
// here, we just check to see if the "signature" is good. you can verify whether or not the assymetric key is good,
// later, with the getServerHostKeyAlgorithm() function
for ($i = 0; $i < count($server_host_key_algorithms) && !in_array($server_host_key_algorithms[$i], $this->server_host_key_algorithms); $i++) {
}
if ($i == count($server_host_key_algorithms)) {
user_error('No compatible server host key algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
if ($public_key_format != $server_host_key_algorithms[$i] || $signature_format != $server_host_key_algorithms[$i]) {
user_error('Sever Host Key Algorithm Mismatch', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
switch ($server_host_key_algorithms[$i]) {
case 'ssh-dss':
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$p = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$q = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$g = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$y = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
/* The value for 'dss_signature_blob' is encoded as a string containing
r, followed by s (which are 160-bit integers, without lengths or
padding, unsigned, and in network byte order). */
$temp = unpack('Nlength', $this->_string_shift($signature, 4));
if ($temp['length'] != 40) {
user_error('Invalid signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$r = new Math_BigInteger($this->_string_shift($signature, 20), 256);
$s = new Math_BigInteger($this->_string_shift($signature, 20), 256);
if ($r->compare($q) >= 0 || $s->compare($q) >= 0) {
user_error('Invalid signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$w = $s->modInverse($q);
$u1 = $w->multiply(new Math_BigInteger(sha1($source), 16));
list(, $u1) = $u1->divide($q);
$u2 = $w->multiply($r);
list(, $u2) = $u2->divide($q);
$g = $g->modPow($u1, $p);
$y = $y->modPow($u2, $p);
$v = $g->multiply($y);
list(, $v) = $v->divide($p);
list(, $v) = $v->divide($q);
if ($v->compare($r) != 0) {
user_error('Invalid signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
}
break;
case 'ssh-rsa':
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$e = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$n = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$nLength = $temp['length'];
$temp = unpack('Nlength', $this->_string_shift($signature, 4));
$s = new Math_BigInteger($this->_string_shift($signature, $temp['length']), 256);
// validate an RSA signature per "8.2 RSASSA-PKCS1-v1_5", "5.2.2 RSAVP1", and "9.1 EMSA-PSS" in the
// following URL:
// ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-1/pkcs-1v2-1.pdf
// also, see SSHRSA.c (rsa2_verifysig) in PuTTy's source.
if ($s->compare(new Math_BigInteger()) < 0 || $s->compare($n->subtract(new Math_BigInteger(1))) > 0) {
user_error('Invalid signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$s = $s->modPow($e, $n);
$s = $s->toBytes();
$h = pack('N4H*', 0x302130, 0x906052b, 0xe03021a, 0x5000414, sha1($source));
$h = chr(0x1) . str_repeat(chr(0xff), $nLength - 3 - strlen($h)) . $h;
if ($s != $h) {
user_error('Bad server signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
}
}
$packet = pack('C', NET_SSH2_MSG_NEWKEYS);
if (!$this->_send_binary_packet($packet)) {
return false;
}
$response = $this->_get_binary_packet();
if ($response === false) {
user_error('Connection closed by server', E_USER_NOTICE);
return false;
}
list(, $type) = unpack('C', $this->_string_shift($response, 1));
if ($type != NET_SSH2_MSG_NEWKEYS) {
user_error('Expected SSH_MSG_NEWKEYS', E_USER_NOTICE);
return false;
}
switch ($encrypt) {
case '3des-cbc':
$this->encrypt = new Crypt_TripleDES();
// $this->encrypt_block_size = 64 / 8 == the default
break;
case 'aes256-cbc':
$this->encrypt = new Crypt_AES();
$this->encrypt_block_size = 16;
// eg. 128 / 8
break;
case 'aes192-cbc':
$this->encrypt = new Crypt_AES();
$this->encrypt_block_size = 16;
break;
case 'aes128-cbc':
$this->encrypt = new Crypt_AES();
$this->encrypt_block_size = 16;
break;
case 'arcfour':
$this->encrypt = new Crypt_RC4();
break;
case 'none':
//$this->encrypt = new Crypt_Null();
}
switch ($decrypt) {
case '3des-cbc':
$this->decrypt = new Crypt_TripleDES();
break;
case 'aes256-cbc':
$this->decrypt = new Crypt_AES();
$this->decrypt_block_size = 16;
break;
case 'aes192-cbc':
$this->decrypt = new Crypt_AES();
$this->decrypt_block_size = 16;
break;
case 'aes128-cbc':
$this->decrypt = new Crypt_AES();
$this->decrypt_block_size = 16;
break;
case 'arcfour':
$this->decrypt = new Crypt_RC4();
break;
case 'none':
//$this->decrypt = new Crypt_Null();
}
$keyBytes = pack('Na*', strlen($keyBytes), $keyBytes);
if ($this->encrypt) {
$this->encrypt->enableContinuousBuffer();
$this->encrypt->disablePadding();
$iv = pack('H*', $hash($keyBytes . $source . 'A' . $this->session_id));
while ($this->encrypt_block_size > strlen($iv)) {
$iv .= pack('H*', $hash($keyBytes . $source . $iv));
}
$this->encrypt->setIV(substr($iv, 0, $this->encrypt_block_size));
$key = pack('H*', $hash($keyBytes . $source . 'C' . $this->session_id));
while ($encryptKeyLength > strlen($key)) {
$key .= pack('H*', $hash($keyBytes . $source . $key));
}
$this->encrypt->setKey(substr($key, 0, $encryptKeyLength));
}
if ($this->decrypt) {
$this->decrypt->enableContinuousBuffer();
$this->decrypt->disablePadding();
$iv = pack('H*', $hash($keyBytes . $source . 'B' . $this->session_id));
while ($this->decrypt_block_size > strlen($iv)) {
$iv .= pack('H*', $hash($keyBytes . $source . $iv));
}
$this->decrypt->setIV(substr($iv, 0, $this->decrypt_block_size));
$key = pack('H*', $hash($keyBytes . $source . 'D' . $this->session_id));
while ($decryptKeyLength > strlen($key)) {
$key .= pack('H*', $hash($keyBytes . $source . $key));
}
$this->decrypt->setKey(substr($key, 0, $decryptKeyLength));
}
for ($i = 0; $i < count($mac_algorithms) && !in_array($mac_algorithms[$i], $this->mac_algorithms_client_to_server); $i++) {
}
if ($i == count($mac_algorithms)) {
user_error('No compatible client to server message authentication algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$createKeyLength = 0;
// ie. $mac_algorithms[$i] == 'none'
switch ($mac_algorithms[$i]) {
case 'hmac-sha1':
$this->hmac_create = new Crypt_Hash('sha1');
$createKeyLength = 20;
break;
case 'hmac-sha1-96':
$this->hmac_create = new Crypt_Hash('sha1-96');
$createKeyLength = 20;
break;
case 'hmac-md5':
$this->hmac_create = new Crypt_Hash('md5');
$createKeyLength = 16;
break;
case 'hmac-md5-96':
$this->hmac_create = new Crypt_Hash('md5-96');
$createKeyLength = 16;
}
for ($i = 0; $i < count($mac_algorithms) && !in_array($mac_algorithms[$i], $this->mac_algorithms_server_to_client); $i++) {
}
if ($i == count($mac_algorithms)) {
user_error('No compatible server to client message authentication algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$checkKeyLength = 0;
$this->hmac_size = 0;
switch ($mac_algorithms[$i]) {
case 'hmac-sha1':
$this->hmac_check = new Crypt_Hash('sha1');
$checkKeyLength = 20;
$this->hmac_size = 20;
break;
case 'hmac-sha1-96':
$this->hmac_check = new Crypt_Hash('sha1-96');
$checkKeyLength = 20;
$this->hmac_size = 12;
break;
case 'hmac-md5':
$this->hmac_check = new Crypt_Hash('md5');
$checkKeyLength = 16;
$this->hmac_size = 16;
break;
case 'hmac-md5-96':
$this->hmac_check = new Crypt_Hash('md5-96');
$checkKeyLength = 16;
$this->hmac_size = 12;
}
$key = pack('H*', $hash($keyBytes . $source . 'E' . $this->session_id));
while ($createKeyLength > strlen($key)) {
$key .= pack('H*', $hash($keyBytes . $source . $key));
}
$this->hmac_create->setKey(substr($key, 0, $createKeyLength));
$key = pack('H*', $hash($keyBytes . $source . 'F' . $this->session_id));
while ($checkKeyLength > strlen($key)) {
$key .= pack('H*', $hash($keyBytes . $source . $key));
}
$this->hmac_check->setKey(substr($key, 0, $checkKeyLength));
for ($i = 0; $i < count($compression_algorithms) && !in_array($compression_algorithms[$i], $this->compression_algorithms_server_to_client); $i++) {
}
if ($i == count($compression_algorithms)) {
user_error('No compatible server to client compression algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$this->decompress = $compression_algorithms[$i] == 'zlib';
for ($i = 0; $i < count($compression_algorithms) && !in_array($compression_algorithms[$i], $this->compression_algorithms_client_to_server); $i++) {
}
if ($i == count($compression_algorithms)) {
user_error('No compatible client to server compression algorithms found', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$this->compress = $compression_algorithms[$i] == 'zlib';
return true;
}
/**
* Key Exchange
*
* @param String $kexinit_payload_server
* @access private
*/
function _key_exchange($kexinit_payload_server)
{
$kex_algorithms = array('*****@*****.**', 'diffie-hellman-group1-sha1', 'diffie-hellman-group14-sha1', 'diffie-hellman-group-exchange-sha1', 'diffie-hellman-group-exchange-sha256');
if (!class_exists('\\Sodium')) {
$kex_algorithms = array_diff($kex_algorithms, array('*****@*****.**'));
}
$server_host_key_algorithms = array('ssh-rsa', 'ssh-dss');
$encryption_algorithms = array('arcfour256', 'arcfour128', 'aes128-ctr', 'aes192-ctr', 'aes256-ctr', 'twofish128-ctr', 'twofish192-ctr', 'twofish256-ctr', 'aes128-cbc', 'aes192-cbc', 'aes256-cbc', 'twofish128-cbc', 'twofish192-cbc', 'twofish256-cbc', 'twofish-cbc', 'blowfish-ctr', 'blowfish-cbc', '3des-ctr', '3des-cbc');
if (extension_loaded('openssl') && !extension_loaded('mcrypt')) {
// OpenSSL does not support arcfour256 in any capacity and arcfour128 / arcfour support is limited to
// instances that do not use continuous buffers
$encryption_algorithms = array_diff($encryption_algorithms, array('arcfour256', 'arcfour128', 'arcfour'));
}
if (class_exists('\\phpseclib\\Crypt\\RC4') === false) {
$encryption_algorithms = array_diff($encryption_algorithms, array('arcfour256', 'arcfour128', 'arcfour'));
}
if (class_exists('\\phpseclib\\Crypt\\Rijndael') === false) {
$encryption_algorithms = array_diff($encryption_algorithms, array('aes128-ctr', 'aes192-ctr', 'aes256-ctr', 'aes128-cbc', 'aes192-cbc', 'aes256-cbc'));
}
if (class_exists('\\phpseclib\\Crypt\\Twofish') === false) {
$encryption_algorithms = array_diff($encryption_algorithms, array('twofish128-ctr', 'twofish192-ctr', 'twofish256-ctr', 'twofish128-cbc', 'twofish192-cbc', 'twofish256-cbc', 'twofish-cbc'));
}
if (class_exists('\\phpseclib\\Crypt\\Blowfish') === false) {
$encryption_algorithms = array_diff($encryption_algorithms, array('blowfish-ctr', 'blowfish-cbc'));
}
if (class_exists('\\phpseclib\\Crypt\\TripleDES') === false) {
$encryption_algorithms = array_diff($encryption_algorithms, array('3des-ctr', '3des-cbc'));
}
$encryption_algorithms = array_values($encryption_algorithms);
$mac_algorithms = array('hmac-sha2-256', 'hmac-sha1-96', 'hmac-sha1', 'hmac-md5-96', 'hmac-md5');
$compression_algorithms = array('none');
// some SSH servers have buggy implementations of some of the above algorithms
switch ($this->server_identifier) {
case 'SSH-2.0-SSHD':
$mac_algorithms = array_values(array_diff($mac_algorithms, array('hmac-sha1-96', 'hmac-md5-96')));
}
$str_kex_algorithms = implode(',', $kex_algorithms);
$str_server_host_key_algorithms = implode(',', $server_host_key_algorithms);
$encryption_algorithms_server_to_client = $encryption_algorithms_client_to_server = implode(',', $encryption_algorithms);
$mac_algorithms_server_to_client = $mac_algorithms_client_to_server = implode(',', $mac_algorithms);
$compression_algorithms_server_to_client = $compression_algorithms_client_to_server = implode(',', $compression_algorithms);
$client_cookie = Random::string(16);
$response = $kexinit_payload_server;
$this->_string_shift($response, 1);
// skip past the message number (it should be SSH_MSG_KEXINIT)
$server_cookie = $this->_string_shift($response, 16);
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->kex_algorithms = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->server_host_key_algorithms = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->encryption_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->encryption_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->mac_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->mac_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->compression_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->compression_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->languages_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->languages_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
extract(unpack('Cfirst_kex_packet_follows', $this->_string_shift($response, 1)));
$first_kex_packet_follows = $first_kex_packet_follows != 0;
// the sending of SSH2_MSG_KEXINIT could go in one of two places. this is the second place.
$kexinit_payload_client = pack('Ca*Na*Na*Na*Na*Na*Na*Na*Na*Na*Na*CN', NET_SSH2_MSG_KEXINIT, $client_cookie, strlen($str_kex_algorithms), $str_kex_algorithms, strlen($str_server_host_key_algorithms), $str_server_host_key_algorithms, strlen($encryption_algorithms_client_to_server), $encryption_algorithms_client_to_server, strlen($encryption_algorithms_server_to_client), $encryption_algorithms_server_to_client, strlen($mac_algorithms_client_to_server), $mac_algorithms_client_to_server, strlen($mac_algorithms_server_to_client), $mac_algorithms_server_to_client, strlen($compression_algorithms_client_to_server), $compression_algorithms_client_to_server, strlen($compression_algorithms_server_to_client), $compression_algorithms_server_to_client, 0, '', 0, '', 0, 0);
if (!$this->_send_binary_packet($kexinit_payload_client)) {
return false;
}
// here ends the second place.
// we need to decide upon the symmetric encryption algorithms before we do the diffie-hellman key exchange
// we don't initialize any crypto-objects, yet - we do that, later. for now, we need the lengths to make the
// diffie-hellman key exchange as fast as possible
$decrypt = $this->_array_intersect_first($encryption_algorithms, $this->encryption_algorithms_server_to_client);
$decryptKeyLength = $this->_encryption_algorithm_to_key_size($decrypt);
if ($decryptKeyLength === null) {
user_error('No compatible server to client encryption algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$encrypt = $this->_array_intersect_first($encryption_algorithms, $this->encryption_algorithms_client_to_server);
$encryptKeyLength = $this->_encryption_algorithm_to_key_size($encrypt);
if ($encryptKeyLength === null) {
user_error('No compatible client to server encryption algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
// through diffie-hellman key exchange a symmetric key is obtained
$kex_algorithm = $this->_array_intersect_first($kex_algorithms, $this->kex_algorithms);
if ($kex_algorithm === false) {
user_error('No compatible key exchange algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
// Only relevant in diffie-hellman-group-exchange-sha{1,256}, otherwise empty.
$exchange_hash_rfc4419 = '';
if ($kex_algorithm === '*****@*****.**') {
$x = Random::string(32);
$eBytes = \Sodium::crypto_box_publickey_from_secretkey($x);
$clientKexInitMessage = NET_SSH2_MSG_KEX_ECDH_INIT;
$serverKexReplyMessage = NET_SSH2_MSG_KEX_ECDH_REPLY;
$kexHash = new Hash('sha256');
} else {
if (strpos($kex_algorithm, 'diffie-hellman-group-exchange') === 0) {
$dh_group_sizes_packed = pack('NNN', $this->kex_dh_group_size_min, $this->kex_dh_group_size_preferred, $this->kex_dh_group_size_max);
$packet = pack('Ca*', NET_SSH2_MSG_KEXDH_GEX_REQUEST, $dh_group_sizes_packed);
if (!$this->_send_binary_packet($packet)) {
return false;
}
$response = $this->_get_binary_packet();
if ($response === false) {
user_error('Connection closed by server');
return false;
}
extract(unpack('Ctype', $this->_string_shift($response, 1)));
if ($type != NET_SSH2_MSG_KEXDH_GEX_GROUP) {
user_error('Expected SSH_MSG_KEX_DH_GEX_GROUP');
return false;
}
extract(unpack('NprimeLength', $this->_string_shift($response, 4)));
$primeBytes = $this->_string_shift($response, $primeLength);
$prime = new BigInteger($primeBytes, -256);
extract(unpack('NgLength', $this->_string_shift($response, 4)));
$gBytes = $this->_string_shift($response, $gLength);
$g = new BigInteger($gBytes, -256);
$exchange_hash_rfc4419 = pack('a*Na*Na*', $dh_group_sizes_packed, $primeLength, $primeBytes, $gLength, $gBytes);
$clientKexInitMessage = NET_SSH2_MSG_KEXDH_GEX_INIT;
$serverKexReplyMessage = NET_SSH2_MSG_KEXDH_GEX_REPLY;
} else {
switch ($kex_algorithm) {
// see http://tools.ietf.org/html/rfc2409#section-6.2 and
// http://tools.ietf.org/html/rfc2412, appendex E
case 'diffie-hellman-group1-sha1':
$prime = 'FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74' . '020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F1437' . '4FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED' . 'EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF';
break;
// see http://tools.ietf.org/html/rfc3526#section-3
// see http://tools.ietf.org/html/rfc3526#section-3
case 'diffie-hellman-group14-sha1':
$prime = 'FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74' . '020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F1437' . '4FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED' . 'EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3DC2007CB8A163BF05' . '98DA48361C55D39A69163FA8FD24CF5F83655D23DCA3AD961C62F356208552BB' . '9ED529077096966D670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B' . 'E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF695581718' . '3995497CEA956AE515D2261898FA051015728E5A8AACAA68FFFFFFFFFFFFFFFF';
break;
}
// For both diffie-hellman-group1-sha1 and diffie-hellman-group14-sha1
// the generator field element is 2 (decimal) and the hash function is sha1.
$g = new BigInteger(2);
$prime = new BigInteger($prime, 16);
$clientKexInitMessage = NET_SSH2_MSG_KEXDH_INIT;
$serverKexReplyMessage = NET_SSH2_MSG_KEXDH_REPLY;
}
switch ($kex_algorithm) {
case 'diffie-hellman-group-exchange-sha256':
$kexHash = new Hash('sha256');
break;
default:
$kexHash = new Hash('sha1');
}
/* To increase the speed of the key exchange, both client and server may
reduce the size of their private exponents. It should be at least
twice as long as the key material that is generated from the shared
secret. For more details, see the paper by van Oorschot and Wiener
[VAN-OORSCHOT].
-- http://tools.ietf.org/html/rfc4419#section-6.2 */
$one = new BigInteger(1);
$keyLength = min($kexHash->getLength(), max($encryptKeyLength, $decryptKeyLength));
$max = $one->bitwise_leftShift(16 * $keyLength);
// 2 * 8 * $keyLength
$max = $max->subtract($one);
$x = $one->random($one, $max);
$e = $g->modPow($x, $prime);
$eBytes = $e->toBytes(true);
}
$data = pack('CNa*', $clientKexInitMessage, strlen($eBytes), $eBytes);
if (!$this->_send_binary_packet($data)) {
user_error('Connection closed by server');
return false;
}
$response = $this->_get_binary_packet();
if ($response === false) {
user_error('Connection closed by server');
return false;
}
extract(unpack('Ctype', $this->_string_shift($response, 1)));
if ($type != $serverKexReplyMessage) {
user_error('Expected SSH_MSG_KEXDH_REPLY');
return false;
}
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->server_public_host_key = $server_public_host_key = $this->_string_shift($response, $temp['length']);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$public_key_format = $this->_string_shift($server_public_host_key, $temp['length']);
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$fBytes = $this->_string_shift($response, $temp['length']);
$temp = unpack('Nlength', $this->_string_shift($response, 4));
$this->signature = $this->_string_shift($response, $temp['length']);
$temp = unpack('Nlength', $this->_string_shift($this->signature, 4));
$this->signature_format = $this->_string_shift($this->signature, $temp['length']);
if ($kex_algorithm === '*****@*****.**') {
if (strlen($fBytes) !== 32) {
user_error('Received curve25519 public key of invalid length.');
return false;
}
$key = new BigInteger(\Sodium::crypto_scalarmult($x, $fBytes), 256);
\Sodium::sodium_memzero($x);
} else {
$f = new BigInteger($fBytes, -256);
$key = $f->modPow($x, $prime);
}
$keyBytes = $key->toBytes(true);
$this->exchange_hash = pack('Na*Na*Na*Na*Na*a*Na*Na*Na*', strlen($this->identifier), $this->identifier, strlen($this->server_identifier), $this->server_identifier, strlen($kexinit_payload_client), $kexinit_payload_client, strlen($kexinit_payload_server), $kexinit_payload_server, strlen($this->server_public_host_key), $this->server_public_host_key, $exchange_hash_rfc4419, strlen($eBytes), $eBytes, strlen($fBytes), $fBytes, strlen($keyBytes), $keyBytes);
$this->exchange_hash = $kexHash->hash($this->exchange_hash);
if ($this->session_id === false) {
$this->session_id = $this->exchange_hash;
}
$server_host_key_algorithm = $this->_array_intersect_first($server_host_key_algorithms, $this->server_host_key_algorithms);
if ($server_host_key_algorithm === false) {
user_error('No compatible server host key algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
if ($public_key_format != $server_host_key_algorithm || $this->signature_format != $server_host_key_algorithm) {
user_error('Server Host Key Algorithm Mismatch');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$packet = pack('C', NET_SSH2_MSG_NEWKEYS);
if (!$this->_send_binary_packet($packet)) {
return false;
}
$response = $this->_get_binary_packet();
if ($response === false) {
user_error('Connection closed by server');
return false;
}
extract(unpack('Ctype', $this->_string_shift($response, 1)));
if ($type != NET_SSH2_MSG_NEWKEYS) {
user_error('Expected SSH_MSG_NEWKEYS');
return false;
}
$keyBytes = pack('Na*', strlen($keyBytes), $keyBytes);
$this->encrypt = $this->_encryption_algorithm_to_crypt_instance($encrypt);
if ($this->encrypt) {
if ($this->crypto_engine) {
$this->encrypt->setEngine($this->crypto_engine);
}
if ($this->encrypt->block_size) {
$this->encrypt_block_size = $this->encrypt->block_size;
}
$this->encrypt->enableContinuousBuffer();
$this->encrypt->disablePadding();
$iv = $kexHash->hash($keyBytes . $this->exchange_hash . 'A' . $this->session_id);
while ($this->encrypt_block_size > strlen($iv)) {
$iv .= $kexHash->hash($keyBytes . $this->exchange_hash . $iv);
}
$this->encrypt->setIV(substr($iv, 0, $this->encrypt_block_size));
$key = $kexHash->hash($keyBytes . $this->exchange_hash . 'C' . $this->session_id);
while ($encryptKeyLength > strlen($key)) {
$key .= $kexHash->hash($keyBytes . $this->exchange_hash . $key);
}
$this->encrypt->setKey(substr($key, 0, $encryptKeyLength));
}
$this->decrypt = $this->_encryption_algorithm_to_crypt_instance($decrypt);
if ($this->decrypt) {
if ($this->crypto_engine) {
$this->decrypt->setEngine($this->crypto_engine);
}
if ($this->decrypt->block_size) {
$this->decrypt_block_size = $this->decrypt->block_size;
}
$this->decrypt->enableContinuousBuffer();
$this->decrypt->disablePadding();
$iv = $kexHash->hash($keyBytes . $this->exchange_hash . 'B' . $this->session_id);
while ($this->decrypt_block_size > strlen($iv)) {
$iv .= $kexHash->hash($keyBytes . $this->exchange_hash . $iv);
}
$this->decrypt->setIV(substr($iv, 0, $this->decrypt_block_size));
$key = $kexHash->hash($keyBytes . $this->exchange_hash . 'D' . $this->session_id);
while ($decryptKeyLength > strlen($key)) {
$key .= $kexHash->hash($keyBytes . $this->exchange_hash . $key);
}
$this->decrypt->setKey(substr($key, 0, $decryptKeyLength));
}
/* The "arcfour128" algorithm is the RC4 cipher, as described in
[SCHNEIER], using a 128-bit key. The first 1536 bytes of keystream
generated by the cipher MUST be discarded, and the first byte of the
first encrypted packet MUST be encrypted using the 1537th byte of
keystream.
-- http://tools.ietf.org/html/rfc4345#section-4 */
if ($encrypt == 'arcfour128' || $encrypt == 'arcfour256') {
$this->encrypt->encrypt(str_repeat("", 1536));
}
if ($decrypt == 'arcfour128' || $decrypt == 'arcfour256') {
$this->decrypt->decrypt(str_repeat("", 1536));
}
$mac_algorithm = $this->_array_intersect_first($mac_algorithms, $this->mac_algorithms_client_to_server);
if ($mac_algorithm === false) {
user_error('No compatible client to server message authentication algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$createKeyLength = 0;
// ie. $mac_algorithm == 'none'
switch ($mac_algorithm) {
case 'hmac-sha2-256':
$this->hmac_create = new Hash('sha256');
$createKeyLength = 32;
break;
case 'hmac-sha1':
$this->hmac_create = new Hash('sha1');
$createKeyLength = 20;
break;
case 'hmac-sha1-96':
$this->hmac_create = new Hash('sha1-96');
$createKeyLength = 20;
break;
case 'hmac-md5':
$this->hmac_create = new Hash('md5');
$createKeyLength = 16;
break;
case 'hmac-md5-96':
$this->hmac_create = new Hash('md5-96');
$createKeyLength = 16;
}
$mac_algorithm = $this->_array_intersect_first($mac_algorithms, $this->mac_algorithms_server_to_client);
if ($mac_algorithm === false) {
user_error('No compatible server to client message authentication algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$checkKeyLength = 0;
$this->hmac_size = 0;
switch ($mac_algorithm) {
case 'hmac-sha2-256':
$this->hmac_check = new Hash('sha256');
$checkKeyLength = 32;
$this->hmac_size = 32;
break;
case 'hmac-sha1':
$this->hmac_check = new Hash('sha1');
$checkKeyLength = 20;
$this->hmac_size = 20;
break;
case 'hmac-sha1-96':
$this->hmac_check = new Hash('sha1-96');
$checkKeyLength = 20;
$this->hmac_size = 12;
break;
case 'hmac-md5':
$this->hmac_check = new Hash('md5');
$checkKeyLength = 16;
$this->hmac_size = 16;
break;
case 'hmac-md5-96':
$this->hmac_check = new Hash('md5-96');
$checkKeyLength = 16;
$this->hmac_size = 12;
}
$key = $kexHash->hash($keyBytes . $this->exchange_hash . 'E' . $this->session_id);
while ($createKeyLength > strlen($key)) {
$key .= $kexHash->hash($keyBytes . $this->exchange_hash . $key);
}
$this->hmac_create->setKey(substr($key, 0, $createKeyLength));
$key = $kexHash->hash($keyBytes . $this->exchange_hash . 'F' . $this->session_id);
while ($checkKeyLength > strlen($key)) {
$key .= $kexHash->hash($keyBytes . $this->exchange_hash . $key);
}
$this->hmac_check->setKey(substr($key, 0, $checkKeyLength));
$compression_algorithm = $this->_array_intersect_first($compression_algorithms, $this->compression_algorithms_server_to_client);
if ($compression_algorithm === false) {
user_error('No compatible server to client compression algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$this->decompress = $compression_algorithm == 'zlib';
$compression_algorithm = $this->_array_intersect_first($compression_algorithms, $this->compression_algorithms_client_to_server);
if ($compression_algorithm === false) {
user_error('No compatible client to server compression algorithms found');
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$this->compress = $compression_algorithm == 'zlib';
return true;
}
/**
* Default Constructor.
*
* Connects to an SSHv1 server
*
* @param String $host
* @param optional Integer $port
* @param optional Integer $timeout
* @param optional Integer $cipher
* @return Net_SSH1
* @access public
*/
function __construct($host, $port = 22, $timeout = 10, $cipher = NET_SSH1_CIPHER_3DES)
{
$this->protocol_flags = array(1 => 'NET_SSH1_MSG_DISCONNECT', 2 => 'NET_SSH1_SMSG_PUBLIC_KEY', 3 => 'NET_SSH1_CMSG_SESSION_KEY', 4 => 'NET_SSH1_CMSG_USER', 9 => 'NET_SSH1_CMSG_AUTH_PASSWORD', 10 => 'NET_SSH1_CMSG_REQUEST_PTY', 12 => 'NET_SSH1_CMSG_EXEC_SHELL', 13 => 'NET_SSH1_CMSG_EXEC_CMD', 14 => 'NET_SSH1_SMSG_SUCCESS', 15 => 'NET_SSH1_SMSG_FAILURE', 16 => 'NET_SSH1_CMSG_STDIN_DATA', 17 => 'NET_SSH1_SMSG_STDOUT_DATA', 18 => 'NET_SSH1_SMSG_STDERR_DATA', 19 => 'NET_SSH1_CMSG_EOF', 20 => 'NET_SSH1_SMSG_EXITSTATUS', 33 => 'NET_SSH1_CMSG_EXIT_CONFIRMATION');
$this->_define_array($this->protocol_flags);
$this->fsock = @fsockopen($host, $port, $errno, $errstr, $timeout);
if (!$this->fsock) {
user_error(rtrim("Cannot connect to {$host}. Error {$errno}. {$errstr}"), E_USER_NOTICE);
return;
}
$this->server_identification = $init_line = fgets($this->fsock, 255);
if (defined('NET_SSH1_LOGGING')) {
$this->protocol_flags_log[] = '<-';
$this->protocol_flags_log[] = '->';
if (NET_SSH1_LOGGING == NET_SSH1_LOG_COMPLEX) {
$this->message_log[] = $this->server_identification;
$this->message_log[] = $this->identifier . "\r\n";
}
}
if (!preg_match('#SSH-([0-9\\.]+)-(.+)#', $init_line, $parts)) {
user_error('Can only connect to SSH servers', E_USER_NOTICE);
return;
}
if ($parts[1][0] != 1) {
user_error("Cannot connect to SSH {$parts['1']} servers", E_USER_NOTICE);
return;
}
fputs($this->fsock, $this->identifier . "\r\n");
$response = $this->_get_binary_packet();
if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_PUBLIC_KEY) {
user_error('Expected SSH_SMSG_PUBLIC_KEY', E_USER_NOTICE);
return;
}
$anti_spoofing_cookie = $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 8);
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$server_key_public_exponent = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->server_key_public_exponent = $server_key_public_exponent;
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$server_key_public_modulus = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->server_key_public_modulus = $server_key_public_modulus;
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$host_key_public_exponent = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->host_key_public_exponent = $host_key_public_exponent;
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$host_key_public_modulus = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->host_key_public_modulus = $host_key_public_modulus;
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
// get a list of the supported ciphers
extract(unpack('Nsupported_ciphers_mask', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4)));
foreach ($this->supported_ciphers as $mask => $name) {
if (($supported_ciphers_mask & 1 << $mask) == 0) {
unset($this->supported_ciphers[$mask]);
}
}
// get a list of the supported authentications
extract(unpack('Nsupported_authentications_mask', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4)));
foreach ($this->supported_authentications as $mask => $name) {
if (($supported_authentications_mask & 1 << $mask) == 0) {
unset($this->supported_authentications[$mask]);
}
}
$session_id = pack('H*', md5($host_key_public_modulus->toBytes() . $server_key_public_modulus->toBytes() . $anti_spoofing_cookie));
$session_key = '';
for ($i = 0; $i < 32; $i++) {
$session_key .= chr(crypt_random(0, 255));
}
$double_encrypted_session_key = $session_key ^ str_pad($session_id, 32, chr(0));
if ($server_key_public_modulus->compare($host_key_public_modulus) < 0) {
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($server_key_public_exponent, $server_key_public_modulus));
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($host_key_public_exponent, $host_key_public_modulus));
} else {
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($host_key_public_exponent, $host_key_public_modulus));
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($server_key_public_exponent, $server_key_public_modulus));
}
$cipher = isset($this->supported_ciphers[$cipher]) ? $cipher : NET_SSH1_CIPHER_3DES;
$data = pack('C2a*na*N', NET_SSH1_CMSG_SESSION_KEY, $cipher, $anti_spoofing_cookie, 8 * strlen($double_encrypted_session_key), $double_encrypted_session_key, 0);
if (!$this->_send_binary_packet($data)) {
user_error('Error sending SSH_CMSG_SESSION_KEY', E_USER_NOTICE);
return;
}
switch ($cipher) {
//case NET_SSH1_CIPHER_NONE:
// $this->crypto = new Crypt_Null();
// break;
case NET_SSH1_CIPHER_DES:
$this->crypto = new Crypt_DES();
$this->crypto->disablePadding();
$this->crypto->enableContinuousBuffer();
$this->crypto->setKey(substr($session_key, 0, 8));
break;
case NET_SSH1_CIPHER_3DES:
$this->crypto = new Crypt_TripleDES(CRYPT_DES_MODE_3CBC);
$this->crypto->disablePadding();
$this->crypto->enableContinuousBuffer();
$this->crypto->setKey(substr($session_key, 0, 24));
break;
//case NET_SSH1_CIPHER_RC4:
// $this->crypto = new Crypt_RC4();
// $this->crypto->enableContinuousBuffer();
// $this->crypto->setKey(substr($session_key, 0, 16));
// break;
}
$response = $this->_get_binary_packet();
if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_SUCCESS) {
user_error('Expected SSH_SMSG_SUCCESS', E_USER_NOTICE);
return;
}
$this->bitmap = NET_SSH1_MASK_CONSTRUCTOR;
}