/** * 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); }