octoleo
/
phpseclib
mirror of https://github.com/phpseclib/phpseclib.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

add setPreferredAlgorithms() and getServerAlgorithms()

This commit is contained in:
terrafrost 2019-03-29 18:44:31 -05:00
parent 0cff98b19e
commit 72209ffd65
1 changed files with 167 additions and 142 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

309
phpseclib/Net/SSH2.php
View File

@ -63,6 +63,7 @@ use phpseclib\Math\BigInteger; // Used to do Diffie-Hellman key exchange and DSA
use phpseclib\System\SSH\Agent;
use phpseclib\System\SSH\Agent\Identity as AgentIdentity;
use phpseclib\Exception\NoSupportedAlgorithmsException;
use phpseclib\Exception\UnsupportedAlgorithmException;
use phpseclib\Common\Functions\Strings;
use phpseclib\Common\Functions\Objects;
@ -328,6 +329,15 @@ class SSH2
*/
private $languages_client_to_server = false;
/**
* Preferred Algorithms
*
* @see self::setPreferredAlgorithms()
* @var array
* @access private
*/
private $preferred = [];
/**
* Block Size for Server to Client Encryption
*
@ -1342,27 +1352,59 @@ class SSH2
*/
private function key_exchange($kexinit_payload_server = false)
{
$kex_algorithms = SSH2::getSupportedKEXAlgorithms();
$server_host_key_algorithms = SSH2::getSupportedHostKeyAlgorithms();
$encryption_algorithms = SSH2::getSupportedEncryptionAlgorithms();
$mac_algorithms = SSH2::getSupportedMACAlgorithms();
$compression_algorithms = SSH2::getSupportedCompressionAlgorithms();
$preferred = $this->preferred;
$kex_algorithms = isset($preferred['kex']) ?
$preferred['kex'] :
SSH2::getSupportedKEXAlgorithms();
$server_host_key_algorithms = isset($preferred['hostkey']) ?
$preferred['hostkey'] :
SSH2::getSupportedHostKeyAlgorithms();
$s2c_encryption_algorithms = isset($preferred['server_to_client']['crypt']) ?
$preferred['server_to_client']['crypt'] :
SSH2::getSupportedEncryptionAlgorithms();
$c2s_encryption_algorithms = isset($preferred['client_to_server']['crypt']) ?
$preferred['client_to_server']['crypt'] :
SSH2::getSupportedEncryptionAlgorithms();
$s2c_mac_algorithms = isset($preferred['server_to_client']['mac']) ?
$preferred['server_to_client']['mac'] :
SSH2::getSupportedMACAlgorithms();
$c2s_mac_algorithms = isset($preferred['client_to_server']['mac']) ?
$preferred['client_to_server']['mac'] :
SSH2::getSupportedMACAlgorithms();
$s2c_compression_algorithms = isset($preferred['server_to_client']['comp']) ?
$preferred['server_to_client']['comp'] :
SSH2::getSupportedCompressionAlgorithms();
$c2s_compression_algorithms = isset($preferred['client_to_server']['comp']) ?
$preferred['client_to_server']['comp'] :
SSH2::getSupportedCompressionAlgorithms();
// some SSH servers have buggy implementations of some of the above algorithms
switch (true) {
case $this->server_identifier == 'SSH-2.0-SSHD':
case substr($this->server_identifier, 0, 13) == 'SSH-2.0-DLINK':
$mac_algorithms = array_values(array_diff(
$mac_algorithms,
['hmac-sha1-96', 'hmac-md5-96']
));
if (!isset($preferred['server_to_client']['mac'])) {
$s2c_mac_algorithms = array_values(array_diff(
$s2c_mac_algorithms,
['hmac-sha1-96', 'hmac-md5-96']
));
}
if (!isset($preferred['client_to_server']['mac'])) {
$c2s_mac_algorithms = array_values(array_diff(
$c2s_mac_algorithms,
['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);
$encryption_algorithms_server_to_client = implode(',', $s2c_encryption_algorithms);
$encryption_algorithms_client_to_server = implode(',', $c2s_encryption_algorithms);
$mac_algorithms_server_to_client = implode(',', $s2c_mac_algorithms);
$mac_algorithms_client_to_server = implode(',', $c2s_mac_algorithms);
$compression_algorithms_server_to_client = implode(',', $s2c_compression_algorithms);
$compression_algorithms_client_to_server = implode(',', $c2s_compression_algorithms);
$client_cookie = Random::string(16);
$kexinit_payload_client = pack(
@ -1432,6 +1474,7 @@ class SSH2
$this->encryption_algorithms_client_to_server = explode(',', Strings::shift($response, $temp['length']));
if (strlen($response) < 4) {
return false;
}
$temp = unpack('Nlength', Strings::shift($response, 4));
@ -1488,14 +1531,14 @@ class SSH2
// 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);
$decrypt = $this->array_intersect_first($s2c_encryption_algorithms, $this->encryption_algorithms_server_to_client);
$decryptKeyLength = $this->encryption_algorithm_to_key_size($decrypt);
if ($decryptKeyLength === null) {
$this->disconnect_helper(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
throw new NoSupportedAlgorithmsException('No compatible server to client encryption algorithms found');
}
$encrypt = $this->array_intersect_first($encryption_algorithms, $this->encryption_algorithms_client_to_server);
$encrypt = $this->array_intersect_first($c2s_encryption_algorithms, $this->encryption_algorithms_client_to_server);
$encryptKeyLength = $this->encryption_algorithm_to_key_size($encrypt);
if ($encryptKeyLength === null) {
$this->disconnect_helper(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
@ -1678,7 +1721,6 @@ class SSH2
}
$temp = unpack('Nlength', Strings::shift($this->signature, 4));
$this->signature_format = Strings::shift($this->signature, $temp['length']);
if ($this->kex_algorithm === 'curve25519-sha256@libssh.org') {
if (strlen($fBytes) !== 32) {
throw new \RuntimeException('Received curve25519 public key of invalid length.');
@ -1835,7 +1877,7 @@ class SSH2
$this->decrypt->setIV(substr($iv, 0, $this->decrypt_block_size));
}
switch ($encrypt) {
switch ($decrypt) {
case 'aes128-gcm@openssh.com':
case 'aes256-gcm@openssh.com':
// see https://tools.ietf.org/html/rfc5647#section-7.1
@ -1876,7 +1918,7 @@ class SSH2
$this->decrypt->decrypt(str_repeat("\0", 1536));
}
$mac_algorithm = $this->array_intersect_first($mac_algorithms, $this->mac_algorithms_client_to_server);
$mac_algorithm = $this->array_intersect_first($c2s_mac_algorithms, $this->mac_algorithms_client_to_server);
if ($mac_algorithm === false) {
$this->disconnect_helper(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
throw new NoSupportedAlgorithmsException('No compatible client to server message authentication algorithms found');
@ -1920,7 +1962,7 @@ class SSH2
$this->hmac_create->name = $mac_algorithm;
}
$mac_algorithm = $this->array_intersect_first($mac_algorithms, $this->mac_algorithms_server_to_client);
$mac_algorithm = $this->array_intersect_first($s2c_mac_algorithms, $this->mac_algorithms_server_to_client);
if ($mac_algorithm === false) {
$this->disconnect_helper(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
throw new NoSupportedAlgorithmsException('No compatible server to client message authentication algorithms found');
@ -1970,14 +2012,14 @@ class SSH2
$this->hmac_check->name = $mac_algorithm;
}
$compression_algorithm = $this->array_intersect_first($compression_algorithms, $this->compression_algorithms_server_to_client);
$compression_algorithm = $this->array_intersect_first($s2c_compression_algorithms, $this->compression_algorithms_server_to_client);
if ($compression_algorithm === false) {
$this->disconnect_helper(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
throw new NoSupportedAlgorithmsException('No compatible server to client compression algorithms found');
}
$this->decompress = $compression_algorithm == 'zlib';
$compression_algorithm = $this->array_intersect_first($compression_algorithms, $this->compression_algorithms_client_to_server);
$compression_algorithm = $this->array_intersect_first($c2s_compression_algorithms, $this->compression_algorithms_client_to_server);
if ($compression_algorithm === false) {
$this->disconnect_helper(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
throw new NoSupportedAlgorithmsException('No compatible client to server compression algorithms found');
@ -4501,133 +4543,31 @@ class SSH2
}
/**
* Return a list of the key exchange algorithms the server supports.
* Returns a list of algorithms the server supports
*
* @return array
* @access public
*/
public function getKexAlgorithms()
public function getServerAlgorithms()
{
$this->connect();
return $this->kex_algorithms;
}
/**
* Return a list of the host key (public key) algorithms the server supports.
*
* @return array
* @access public
*/
public function getServerHostKeyAlgorithms()
{
$this->connect();
return $this->server_host_key_algorithms;
}
/**
* Return a list of the (symmetric key) encryption algorithms the server supports, when receiving stuff from the client.
*
* @return array
* @access public
*/
public function getEncryptionAlgorithmsClient2Server()
{
$this->connect();
return $this->encryption_algorithms_client_to_server;
}
/**
* Return a list of the (symmetric key) encryption algorithms the server supports, when sending stuff to the client.
*
* @return array
* @access public
*/
public function getEncryptionAlgorithmsServer2Client()
{
$this->connect();
return $this->encryption_algorithms_server_to_client;
}
/**
* Return a list of the MAC algorithms the server supports, when receiving stuff from the client.
*
* @return array
* @access public
*/
public function getMACAlgorithmsClient2Server()
{
$this->connect();
return $this->mac_algorithms_client_to_server;
}
/**
* Return a list of the MAC algorithms the server supports, when sending stuff to the client.
*
* @return array
* @access public
*/
public function getMACAlgorithmsServer2Client()
{
$this->connect();
return $this->mac_algorithms_server_to_client;
}
/**
* Return a list of the compression algorithms the server supports, when receiving stuff from the client.
*
* @return array
* @access public
*/
public function getCompressionAlgorithmsClient2Server()
{
$this->connect();
return $this->compression_algorithms_client_to_server;
}
/**
* Return a list of the compression algorithms the server supports, when sending stuff to the client.
*
* @return array
* @access public
*/
public function getCompressionAlgorithmsServer2Client()
{
$this->connect();
return $this->compression_algorithms_server_to_client;
}
/**
* Return a list of the languages the server supports, when sending stuff to the client.
*
* @return array
* @access public
*/
public function getLanguagesServer2Client()
{
$this->connect();
return $this->languages_server_to_client;
}
/**
* Return a list of the languages the server supports, when receiving stuff from the client.
*
* @return array
* @access public
*/
public function getLanguagesClient2Server()
{
$this->connect();
return $this->languages_client_to_server;
return [
'kex' => $this->kex_algorithms,
'hostkey' => $this->server_host_key_algorithms,
'client_to_server' => [
'crypt' => $this->encryption_algorithms_client_to_server,
'mac' => $this->mac_algorithms_client_to_server,
'comp' => $this->compression_algorithms_client_to_server,
'lang' => $this->languages_client_to_server
],
'server_to_client' => [
'crypt' => $this->encryption_algorithms_server_to_client,
'mac' => $this->mac_algorithms_server_to_client,
'comp' => $this->compression_algorithms_server_to_client,
'lang' => $this->languages_server_to_client
]
];
}
/**
@ -4816,14 +4756,14 @@ class SSH2
}
/**
* Return list of negotiated methods
* Return list of negotiated algorithms
*
* Uses the same format as https://www.php.net/ssh2-methods-negotiated
*
* @return array
* @access public
*/
public function getMethodsNegotiated()
public function getAlgorithmsNegotiated()
{
$this->connect();
@ -4843,6 +4783,91 @@ class SSH2
];
}
/**
* Accepts an associative array with up to four parameters as described at
* <https://www.php.net/manual/en/function.ssh2-connect.php>
*
* @param array $methods
* @access public
*/
public function setPreferredAlgorithms(array $methods)
{
$preferred = $methods;
if (isset($preferred['kex'])) {
$preferred['kex'] = array_intersect(
$preferred['kex'],
static::getSupportedKEXAlgorithms()
);
}
if (isset($preferred['hostkey'])) {
$preferred['hostkey'] = array_intersect(
$preferred['hostkey'],
static::getSupportedHostKeyAlgorithms()
);
}
$keys = ['client_to_server', 'server_to_client'];
foreach ($keys as $key) {
if (isset($preferred[$key])) {
$a = &$preferred[$key];
if (isset($a['crypt'])) {
$a['crypt'] = array_intersect(
$a['crypt'],
static::getSupportedEncryptionAlgorithms()
);
}
if (isset($a['comp'])) {
$a['comp'] = array_intersect(
$a['comp'],
static::getSupportedCompressionAlgorithms()
);
}
if (isset($a['mac'])) {
$a['mac'] = array_intersect(
$a['mac'],
static::getSupportedMACAlgorithms()
);
}
}
}
$keys = [
'kex',
'hostkey',
'client_to_server/crypt',
'client_to_server/comp',
'client_to_server/mac',
'server_to_client/crypt',
'server_to_client/comp',
'server_to_client/mac',
];
foreach ($keys as $key) {
$p = $preferred;
$m = $methods;
$subkeys = explode('/', $key);
foreach ($subkeys as $subkey) {
if (!isset($p[$subkey])) {
continue 2;
}
$p = $p[$subkey];
$m = $m[$subkey];
}
if (count($p) != count($m)) {
$diff = array_diff($m, $p);
$msg = count($diff) == 1 ?
' is not a supported algorithm' :
' are not supported algorithms';
throw new UnsupportedAlgorithmException(implode(', ', $diff) . $msg);
}
}
$this->preferred = $preferred;
}
/**
* Returns the banner message.
*