/**
* Convert a binary string into a hexadecimal string without cache-timing
* leaks
*
* @param string $bin_string (raw binary)
* @return string
*/
public static function hexDecodeUpper(string $bin_string) : string
{
return Hex::decode($bin_string);
}
/**
* Connect to an SSHv1 server
*
* @return bool
* @throws \UnexpectedValueException on receipt of unexpected packets
* @throws \RuntimeException on other errors
* @access private
*/
function _connect()
{
$this->fsock = @fsockopen($this->host, $this->port, $errno, $errstr, $this->connectionTimeout);
if (!$this->fsock) {
throw new \RuntimeException(rtrim("Cannot connect to {$host}. Error {$errno}. {$errstr}"));
}
$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, $parts)) {
throw new \RuntimeException('Can only connect to SSH servers');
}
if ($parts[1][0] != 1) {
throw new \RuntimeException("Cannot connect to {$parts['1']} servers");
}
fputs($this->fsock, $this->identifier . "\r\n");
$response = $this->_get_binary_packet();
if ($response[self::RESPONSE_TYPE] != NET_SSH1_SMSG_PUBLIC_KEY) {
throw new \UnexpectedValueException('Expected SSH_SMSG_PUBLIC_KEY');
}
$anti_spoofing_cookie = $this->_string_shift($response[self::RESPONSE_DATA], 8);
$this->_string_shift($response[self::RESPONSE_DATA], 4);
$temp = unpack('nlen', $this->_string_shift($response[self::RESPONSE_DATA], 2));
$server_key_public_exponent = new BigInteger($this->_string_shift($response[self::RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->server_key_public_exponent = $server_key_public_exponent;
$temp = unpack('nlen', $this->_string_shift($response[self::RESPONSE_DATA], 2));
$server_key_public_modulus = new BigInteger($this->_string_shift($response[self::RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->server_key_public_modulus = $server_key_public_modulus;
$this->_string_shift($response[self::RESPONSE_DATA], 4);
$temp = unpack('nlen', $this->_string_shift($response[self::RESPONSE_DATA], 2));
$host_key_public_exponent = new BigInteger($this->_string_shift($response[self::RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->host_key_public_exponent = $host_key_public_exponent;
$temp = unpack('nlen', $this->_string_shift($response[self::RESPONSE_DATA], 2));
$host_key_public_modulus = new BigInteger($this->_string_shift($response[self::RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->host_key_public_modulus = $host_key_public_modulus;
$this->_string_shift($response[self::RESPONSE_DATA], 4);
// get a list of the supported ciphers
extract(unpack('Nsupported_ciphers_mask', $this->_string_shift($response[self::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[self::RESPONSE_DATA], 4)));
foreach ($this->supported_authentications as $mask => $name) {
if (($supported_authentications_mask & 1 << $mask) == 0) {
unset($this->supported_authentications[$mask]);
}
}
$session_id = Hex::decode(md5($host_key_public_modulus->toBytes() . $server_key_public_modulus->toBytes() . $anti_spoofing_cookie));
$session_key = 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 : self::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($data)) {
throw new \RuntimeException('Error sending SSH_CMSG_SESSION_KEY');
}
switch ($cipher) {
//case self::CIPHER_NONE:
// $this->crypto = new \phpseclib\Crypt\Null();
// break;
case self::CIPHER_DES:
$this->crypto = new DES(DES::MODE_CBC);
$this->crypto->disablePadding();
$this->crypto->enableContinuousBuffer();
$this->crypto->setKey(substr($session_key, 0, 8));
// "The iv (initialization vector) is initialized to all zeroes."
$this->crypto->setIV(str_repeat("", 8));
break;
case self::CIPHER_3DES:
$this->crypto = new TripleDES(TripleDES::MODE_3CBC);
$this->crypto->disablePadding();
$this->crypto->enableContinuousBuffer();
$this->crypto->setKey(substr($session_key, 0, 24));
// "All three initialization vectors are initialized to zero."
$this->crypto->setIV(str_repeat("", 8));
break;
//case self::CIPHER_RC4:
// $this->crypto = new RC4();
// $this->crypto->enableContinuousBuffer();
// $this->crypto->setKey(substr($session_key, 0, 16));
// break;
}
$response = $this->_get_binary_packet();
if ($response[self::RESPONSE_TYPE] != NET_SSH1_SMSG_SUCCESS) {
throw new \UnexpectedValueException('Expected SSH_SMSG_SUCCESS');
}
$this->bitmap = self::MASK_CONNECTED;
return true;
}
/**
* RFC 4648 Base16 decoding
*
* "666F6F" -> "foo"
*
* @param string $str
* @return string
*/
public function base16Decode(string $str) : string
{
return Hex::decode($str, true);
}
