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Diffstat (limited to 'vendor/phpseclib/phpseclib/phpseclib/Net/SSH2.php')
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diff --git a/vendor/phpseclib/phpseclib/phpseclib/Net/SSH2.php b/vendor/phpseclib/phpseclib/phpseclib/Net/SSH2.php new file mode 100644 index 0000000..ac70af9 --- /dev/null +++ b/vendor/phpseclib/phpseclib/phpseclib/Net/SSH2.php @@ -0,0 +1,5397 @@ +<?php + +/** + * Pure-PHP implementation of SSHv2. + * + * PHP version 5 + * + * Here are some examples of how to use this library: + * <code> + * <?php + * include 'vendor/autoload.php'; + * + * $ssh = new \phpseclib3\Net\SSH2('www.domain.tld'); + * if (!$ssh->login('username', 'password')) { + * exit('Login Failed'); + * } + * + * echo $ssh->exec('pwd'); + * echo $ssh->exec('ls -la'); + * ?> + * </code> + * + * <code> + * <?php + * include 'vendor/autoload.php'; + * + * $key = \phpseclib3\Crypt\PublicKeyLoader::load('...', '(optional) password'); + * + * $ssh = new \phpseclib3\Net\SSH2('www.domain.tld'); + * if (!$ssh->login('username', $key)) { + * exit('Login Failed'); + * } + * + * echo $ssh->read('username@username:~$'); + * $ssh->write("ls -la\n"); + * echo $ssh->read('username@username:~$'); + * ?> + * </code> + * + * @author Jim Wigginton <[email protected]> + * @copyright 2007 Jim Wigginton + * @license http://www.opensource.org/licenses/mit-license.html MIT License + * @link http://phpseclib.sourceforge.net + */ + +namespace phpseclib3\Net; + +use phpseclib3\Common\Functions\Strings; +use phpseclib3\Crypt\Blowfish; +use phpseclib3\Crypt\ChaCha20; +use phpseclib3\Crypt\Common\AsymmetricKey; +use phpseclib3\Crypt\Common\PrivateKey; +use phpseclib3\Crypt\Common\PublicKey; +use phpseclib3\Crypt\Common\SymmetricKey; +use phpseclib3\Crypt\DH; +use phpseclib3\Crypt\DSA; +use phpseclib3\Crypt\EC; +use phpseclib3\Crypt\Hash; +use phpseclib3\Crypt\Random; +use phpseclib3\Crypt\RC4; +use phpseclib3\Crypt\Rijndael; +use phpseclib3\Crypt\RSA; +use phpseclib3\Crypt\TripleDES; // Used to do Diffie-Hellman key exchange and DSA/RSA signature verification. +use phpseclib3\Crypt\Twofish; +use phpseclib3\Exception\ConnectionClosedException; +use phpseclib3\Exception\InsufficientSetupException; +use phpseclib3\Exception\NoSupportedAlgorithmsException; +use phpseclib3\Exception\UnableToConnectException; +use phpseclib3\Exception\UnsupportedAlgorithmException; +use phpseclib3\Exception\UnsupportedCurveException; +use phpseclib3\Math\BigInteger; +use phpseclib3\System\SSH\Agent; + +/** + * Pure-PHP implementation of SSHv2. + * + * @author Jim Wigginton <[email protected]> + */ +class SSH2 +{ + /**#@+ + * Compression Types + * + */ + /** + * No compression + */ + const NET_SSH2_COMPRESSION_NONE = 1; + /** + * zlib compression + */ + const NET_SSH2_COMPRESSION_ZLIB = 2; + /** + */ + const NET_SSH2_COMPRESSION_ZLIB_AT_OPENSSH = 3; + /**#@-*/ + + // Execution Bitmap Masks + const MASK_CONSTRUCTOR = 0x00000001; + const MASK_CONNECTED = 0x00000002; + const MASK_LOGIN_REQ = 0x00000004; + const MASK_LOGIN = 0x00000008; + const MASK_SHELL = 0x00000010; + const MASK_WINDOW_ADJUST = 0x00000020; + + /* + * Channel constants + * + * RFC4254 refers not to client and server channels but rather to sender and recipient channels. we don't refer + * to them in that way because RFC4254 toggles the meaning. the client sends a SSH_MSG_CHANNEL_OPEN message with + * a sender channel and the server sends a SSH_MSG_CHANNEL_OPEN_CONFIRMATION in response, with a sender and a + * recipient channel. at first glance, you might conclude that SSH_MSG_CHANNEL_OPEN_CONFIRMATION's sender channel + * would be the same thing as SSH_MSG_CHANNEL_OPEN's sender channel, but it's not, per this snippet: + * The 'recipient channel' is the channel number given in the original + * open request, and 'sender channel' is the channel number allocated by + * the other side. + * + * @see \phpseclib3\Net\SSH2::send_channel_packet() + * @see \phpseclib3\Net\SSH2::get_channel_packet() + */ + const CHANNEL_EXEC = 1; // PuTTy uses 0x100 + const CHANNEL_SHELL = 2; + const CHANNEL_SUBSYSTEM = 3; + const CHANNEL_AGENT_FORWARD = 4; + const CHANNEL_KEEP_ALIVE = 5; + + /** + * Returns the message numbers + * + * @see \phpseclib3\Net\SSH2::getLog() + */ + const LOG_SIMPLE = 1; + /** + * Returns the message content + * + * @see \phpseclib3\Net\SSH2::getLog() + */ + const LOG_COMPLEX = 2; + /** + * Outputs the content real-time + */ + const LOG_REALTIME = 3; + /** + * Dumps the content real-time to a file + */ + const LOG_REALTIME_FILE = 4; + /** + * Outputs the message numbers real-time + */ + const LOG_SIMPLE_REALTIME = 5; + /** + * Make sure that the log never gets larger than this + * + * @see \phpseclib3\Net\SSH2::getLog() + */ + const LOG_MAX_SIZE = 1048576; // 1024 * 1024 + + /** + * Returns when a string matching $expect exactly is found + * + * @see \phpseclib3\Net\SSH2::read() + */ + const READ_SIMPLE = 1; + /** + * Returns when a string matching the regular expression $expect is found + * + * @see \phpseclib3\Net\SSH2::read() + */ + const READ_REGEX = 2; + /** + * Returns whenever a data packet is received. + * + * Some data packets may only contain a single character so it may be necessary + * to call read() multiple times when using this option + * + * @see \phpseclib3\Net\SSH2::read() + */ + const READ_NEXT = 3; + + /** + * The SSH identifier + * + * @var string + */ + private $identifier; + + /** + * The Socket Object + * + * @var resource|closed-resource|null + */ + public $fsock; + + /** + * Execution Bitmap + * + * The bits that are set represent functions that have been called already. This is used to determine + * if a requisite function has been successfully executed. If not, an error should be thrown. + * + * @var int + */ + protected $bitmap = 0; + + /** + * Error information + * + * @see self::getErrors() + * @see self::getLastError() + * @var array + */ + private $errors = []; + + /** + * Server Identifier + * + * @see self::getServerIdentification() + * @var string|false + */ + protected $server_identifier = false; + + /** + * Key Exchange Algorithms + * + * @see self::getKexAlgorithims() + * @var array|false + */ + private $kex_algorithms = false; + + /** + * Key Exchange Algorithm + * + * @see self::getMethodsNegotiated() + * @var string|false + */ + private $kex_algorithm = false; + + /** + * Minimum Diffie-Hellman Group Bit Size in RFC 4419 Key Exchange Methods + * + * @see self::_key_exchange() + * @var int + */ + private $kex_dh_group_size_min = 1536; + + /** + * Preferred Diffie-Hellman Group Bit Size in RFC 4419 Key Exchange Methods + * + * @see self::_key_exchange() + * @var int + */ + private $kex_dh_group_size_preferred = 2048; + + /** + * Maximum Diffie-Hellman Group Bit Size in RFC 4419 Key Exchange Methods + * + * @see self::_key_exchange() + * @var int + */ + private $kex_dh_group_size_max = 4096; + + /** + * Server Host Key Algorithms + * + * @see self::getServerHostKeyAlgorithms() + * @var array|false + */ + private $server_host_key_algorithms = false; + + /** + * Supported Private Key Algorithms + * + * In theory this should be the same as the Server Host Key Algorithms but, in practice, + * some servers (eg. Azure) will support rsa-sha2-512 as a server host key algorithm but + * not a private key algorithm + * + * @see self::privatekey_login() + * @var array|false + */ + private $supported_private_key_algorithms = false; + + /** + * Encryption Algorithms: Client to Server + * + * @see self::getEncryptionAlgorithmsClient2Server() + * @var array|false + */ + private $encryption_algorithms_client_to_server = false; + + /** + * Encryption Algorithms: Server to Client + * + * @see self::getEncryptionAlgorithmsServer2Client() + * @var array|false + */ + private $encryption_algorithms_server_to_client = false; + + /** + * MAC Algorithms: Client to Server + * + * @see self::getMACAlgorithmsClient2Server() + * @var array|false + */ + private $mac_algorithms_client_to_server = false; + + /** + * MAC Algorithms: Server to Client + * + * @see self::getMACAlgorithmsServer2Client() + * @var array|false + */ + private $mac_algorithms_server_to_client = false; + + /** + * Compression Algorithms: Client to Server + * + * @see self::getCompressionAlgorithmsClient2Server() + * @var array|false + */ + private $compression_algorithms_client_to_server = false; + + /** + * Compression Algorithms: Server to Client + * + * @see self::getCompressionAlgorithmsServer2Client() + * @var array|false + */ + private $compression_algorithms_server_to_client = false; + + /** + * Languages: Server to Client + * + * @see self::getLanguagesServer2Client() + * @var array|false + */ + private $languages_server_to_client = false; + + /** + * Languages: Client to Server + * + * @see self::getLanguagesClient2Server() + * @var array|false + */ + private $languages_client_to_server = false; + + /** + * Preferred Algorithms + * + * @see self::setPreferredAlgorithms() + * @var array + */ + private $preferred = []; + + /** + * Block Size for Server to Client Encryption + * + * "Note that the length of the concatenation of 'packet_length', + * 'padding_length', 'payload', and 'random padding' MUST be a multiple + * of the cipher block size or 8, whichever is larger. This constraint + * MUST be enforced, even when using stream ciphers." + * + * -- http://tools.ietf.org/html/rfc4253#section-6 + * + * @see self::__construct() + * @see self::_send_binary_packet() + * @var int + */ + private $encrypt_block_size = 8; + + /** + * Block Size for Client to Server Encryption + * + * @see self::__construct() + * @see self::_get_binary_packet() + * @var int + */ + private $decrypt_block_size = 8; + + /** + * Server to Client Encryption Object + * + * @see self::_get_binary_packet() + * @var SymmetricKey|false + */ + private $decrypt = false; + + /** + * Decryption Algorithm Name + * + * @var string|null + */ + private $decryptName; + + /** + * Decryption Invocation Counter + * + * Used by GCM + * + * @var string|null + */ + private $decryptInvocationCounter; + + /** + * Fixed Part of Nonce + * + * Used by GCM + * + * @var string|null + */ + private $decryptFixedPart; + + /** + * Server to Client Length Encryption Object + * + * @see self::_get_binary_packet() + * @var object + */ + private $lengthDecrypt = false; + + /** + * Client to Server Encryption Object + * + * @see self::_send_binary_packet() + * @var SymmetricKey|false + */ + private $encrypt = false; + + /** + * Encryption Algorithm Name + * + * @var string|null + */ + private $encryptName; + + /** + * Encryption Invocation Counter + * + * Used by GCM + * + * @var string|null + */ + private $encryptInvocationCounter; + + /** + * Fixed Part of Nonce + * + * Used by GCM + * + * @var string|null + */ + private $encryptFixedPart; + + /** + * Client to Server Length Encryption Object + * + * @see self::_send_binary_packet() + * @var object + */ + private $lengthEncrypt = false; + + /** + * Client to Server HMAC Object + * + * @see self::_send_binary_packet() + * @var object + */ + private $hmac_create = false; + + /** + * Client to Server HMAC Name + * + * @var string|false + */ + private $hmac_create_name; + + /** + * Client to Server ETM + * + * @var int|false + */ + private $hmac_create_etm; + + /** + * Server to Client HMAC Object + * + * @see self::_get_binary_packet() + * @var object + */ + private $hmac_check = false; + + /** + * Server to Client HMAC Name + * + * @var string|false + */ + private $hmac_check_name; + + /** + * Server to Client ETM + * + * @var int|false + */ + private $hmac_check_etm; + + /** + * Size of server to client HMAC + * + * We need to know how big the HMAC will be for the server to client direction so that we know how many bytes to read. + * For the client to server side, the HMAC object will make the HMAC as long as it needs to be. All we need to do is + * append it. + * + * @see self::_get_binary_packet() + * @var int + */ + private $hmac_size = false; + + /** + * Server Public Host Key + * + * @see self::getServerPublicHostKey() + * @var string + */ + private $server_public_host_key; + + /** + * Session identifier + * + * "The exchange hash H from the first key exchange is additionally + * used as the session identifier, which is a unique identifier for + * this connection." + * + * -- http://tools.ietf.org/html/rfc4253#section-7.2 + * + * @see self::_key_exchange() + * @var string + */ + private $session_id = false; + + /** + * Exchange hash + * + * The current exchange hash + * + * @see self::_key_exchange() + * @var string + */ + private $exchange_hash = false; + + /** + * Message Numbers + * + * @see self::__construct() + * @var array + * @access private + */ + private static $message_numbers = []; + + /** + * Disconnection Message 'reason codes' defined in RFC4253 + * + * @see self::__construct() + * @var array + * @access private + */ + private static $disconnect_reasons = []; + + /** + * SSH_MSG_CHANNEL_OPEN_FAILURE 'reason codes', defined in RFC4254 + * + * @see self::__construct() + * @var array + * @access private + */ + private static $channel_open_failure_reasons = []; + + /** + * Terminal Modes + * + * @link http://tools.ietf.org/html/rfc4254#section-8 + * @see self::__construct() + * @var array + * @access private + */ + private static $terminal_modes = []; + + /** + * SSH_MSG_CHANNEL_EXTENDED_DATA's data_type_codes + * + * @link http://tools.ietf.org/html/rfc4254#section-5.2 + * @see self::__construct() + * @var array + * @access private + */ + private static $channel_extended_data_type_codes = []; + + /** + * Send Sequence Number + * + * See 'Section 6.4. Data Integrity' of rfc4253 for more info. + * + * @see self::_send_binary_packet() + * @var int + */ + private $send_seq_no = 0; + + /** + * Get Sequence Number + * + * See 'Section 6.4. Data Integrity' of rfc4253 for more info. + * + * @see self::_get_binary_packet() + * @var int + */ + private $get_seq_no = 0; + + /** + * Server Channels + * + * Maps client channels to server channels + * + * @see self::get_channel_packet() + * @see self::exec() + * @var array + */ + protected $server_channels = []; + + /** + * Channel Buffers + * + * If a client requests a packet from one channel but receives two packets from another those packets should + * be placed in a buffer + * + * @see self::get_channel_packet() + * @see self::exec() + * @var array + */ + private $channel_buffers = []; + + /** + * Channel Status + * + * Contains the type of the last sent message + * + * @see self::get_channel_packet() + * @var array + */ + protected $channel_status = []; + + /** + * The identifier of the interactive channel which was opened most recently + * + * @see self::getInteractiveChannelId() + * @var int + */ + private $channel_id_last_interactive = 0; + + /** + * Packet Size + * + * Maximum packet size indexed by channel + * + * @see self::send_channel_packet() + * @var array + */ + private $packet_size_client_to_server = []; + + /** + * Message Number Log + * + * @see self::getLog() + * @var array + */ + private $message_number_log = []; + + /** + * Message Log + * + * @see self::getLog() + * @var array + */ + private $message_log = []; + + /** + * The Window Size + * + * Bytes the other party can send before it must wait for the window to be adjusted (0x7FFFFFFF = 2GB) + * + * @var int + * @see self::send_channel_packet() + * @see self::exec() + */ + protected $window_size = 0x7FFFFFFF; + + /** + * What we resize the window to + * + * When PuTTY resizes the window it doesn't add an additional 0x7FFFFFFF bytes - it adds 0x40000000 bytes. + * Some SFTP clients (GoAnywhere) don't support adding 0x7FFFFFFF to the window size after the fact so + * we'll just do what PuTTY does + * + * @var int + * @see self::_send_channel_packet() + * @see self::exec() + */ + private $window_resize = 0x40000000; + + /** + * Window size, server to client + * + * Window size indexed by channel + * + * @see self::send_channel_packet() + * @var array + */ + protected $window_size_server_to_client = []; + + /** + * Window size, client to server + * + * Window size indexed by channel + * + * @see self::get_channel_packet() + * @var array + */ + private $window_size_client_to_server = []; + + /** + * Server signature + * + * Verified against $this->session_id + * + * @see self::getServerPublicHostKey() + * @var string + */ + private $signature = ''; + + /** + * Server signature format + * + * ssh-rsa or ssh-dss. + * + * @see self::getServerPublicHostKey() + * @var string + */ + private $signature_format = ''; + + /** + * Interactive Buffer + * + * @see self::read() + * @var string + */ + private $interactiveBuffer = ''; + + /** + * Current log size + * + * Should never exceed self::LOG_MAX_SIZE + * + * @see self::_send_binary_packet() + * @see self::_get_binary_packet() + * @var int + */ + private $log_size; + + /** + * Timeout + * + * @see self::setTimeout() + */ + protected $timeout; + + /** + * Current Timeout + * + * @see self::get_channel_packet() + */ + protected $curTimeout; + + /** + * Keep Alive Interval + * + * @see self::setKeepAlive() + */ + private $keepAlive; + + /** + * Real-time log file pointer + * + * @see self::_append_log() + * @var resource|closed-resource + */ + private $realtime_log_file; + + /** + * Real-time log file size + * + * @see self::_append_log() + * @var int + */ + private $realtime_log_size; + + /** + * Has the signature been validated? + * + * @see self::getServerPublicHostKey() + * @var bool + */ + private $signature_validated = false; + + /** + * Real-time log file wrap boolean + * + * @see self::_append_log() + * @var bool + */ + private $realtime_log_wrap; + + /** + * Flag to suppress stderr from output + * + * @see self::enableQuietMode() + */ + private $quiet_mode = false; + + /** + * Time of first network activity + * + * @var float + */ + private $last_packet; + + /** + * Exit status returned from ssh if any + * + * @var int + */ + private $exit_status; + + /** + * Flag to request a PTY when using exec() + * + * @var bool + * @see self::enablePTY() + */ + private $request_pty = false; + + /** + * Contents of stdError + * + * @var string + */ + private $stdErrorLog; + + /** + * The Last Interactive Response + * + * @see self::_keyboard_interactive_process() + * @var string + */ + private $last_interactive_response = ''; + + /** + * Keyboard Interactive Request / Responses + * + * @see self::_keyboard_interactive_process() + * @var array + */ + private $keyboard_requests_responses = []; + + /** + * Banner Message + * + * Quoting from the RFC, "in some jurisdictions, sending a warning message before + * authentication may be relevant for getting legal protection." + * + * @see self::_filter() + * @see self::getBannerMessage() + * @var string + */ + private $banner_message = ''; + + /** + * Did read() timeout or return normally? + * + * @see self::isTimeout() + * @var bool + */ + private $is_timeout = false; + + /** + * Log Boundary + * + * @see self::_format_log() + * @var string + */ + private $log_boundary = ':'; + + /** + * Log Long Width + * + * @see self::_format_log() + * @var int + */ + private $log_long_width = 65; + + /** + * Log Short Width + * + * @see self::_format_log() + * @var int + */ + private $log_short_width = 16; + + /** + * Hostname + * + * @see self::__construct() + * @see self::_connect() + * @var string + */ + private $host; + + /** + * Port Number + * + * @see self::__construct() + * @see self::_connect() + * @var int + */ + private $port; + + /** + * Number of columns for terminal window size + * + * @see self::getWindowColumns() + * @see self::setWindowColumns() + * @see self::setWindowSize() + * @var int + */ + private $windowColumns = 80; + + /** + * Number of columns for terminal window size + * + * @see self::getWindowRows() + * @see self::setWindowRows() + * @see self::setWindowSize() + * @var int + */ + private $windowRows = 24; + + /** + * Crypto Engine + * + * @see self::setCryptoEngine() + * @see self::_key_exchange() + * @var int + */ + private static $crypto_engine = false; + + /** + * A System_SSH_Agent for use in the SSH2 Agent Forwarding scenario + * + * @var Agent + */ + private $agent; + + /** + * Connection storage to replicates ssh2 extension functionality: + * {@link http://php.net/manual/en/wrappers.ssh2.php#refsect1-wrappers.ssh2-examples} + * + * @var array<string, SSH2|\WeakReference<SSH2>> + */ + private static $connections; + + /** + * Send the identification string first? + * + * @var bool + */ + private $send_id_string_first = true; + + /** + * Send the key exchange initiation packet first? + * + * @var bool + */ + private $send_kex_first = true; + + /** + * Some versions of OpenSSH incorrectly calculate the key size + * + * @var bool + */ + private $bad_key_size_fix = false; + + /** + * Should we try to re-connect to re-establish keys? + * + * @var bool + */ + private $retry_connect = false; + + /** + * Binary Packet Buffer + * + * @var string|false + */ + private $binary_packet_buffer = false; + + /** + * Preferred Signature Format + * + * @var string|false + */ + protected $preferred_signature_format = false; + + /** + * Authentication Credentials + * + * @var array + */ + protected $auth = []; + + /** + * Terminal + * + * @var string + */ + private $term = 'vt100'; + + /** + * The authentication methods that may productively continue authentication. + * + * @see https://tools.ietf.org/html/rfc4252#section-5.1 + * @var array|null + */ + private $auth_methods_to_continue = null; + + /** + * Compression method + * + * @var int + */ + private $compress = self::NET_SSH2_COMPRESSION_NONE; + + /** + * Decompression method + * + * @var int + */ + private $decompress = self::NET_SSH2_COMPRESSION_NONE; + + /** + * Compression context + * + * @var resource|false|null + */ + private $compress_context; + + /** + * Decompression context + * + * @var resource|object + */ + private $decompress_context; + + /** + * Regenerate Compression Context + * + * @var bool + */ + private $regenerate_compression_context = false; + + /** + * Regenerate Decompression Context + * + * @var bool + */ + private $regenerate_decompression_context = false; + + /** + * Smart multi-factor authentication flag + * + * @var bool + */ + private $smartMFA = true; + + /** + * How many channels are currently opened + * + * @var int + */ + private $channelCount = 0; + + /** + * Does the server support multiple channels? If not then error out + * when multiple channels are attempted to be opened + * + * @var bool + */ + private $errorOnMultipleChannels; + + /** + * Terrapin Countermeasure + * + * "During initial KEX, terminate the connection if any unexpected or out-of-sequence packet is received" + * -- https://github.com/openssh/openssh-portable/commit/1edb00c58f8a6875fad6a497aa2bacf37f9e6cd5 + * + * @var int + */ + private $extra_packets; + + /** + * Default Constructor. + * + * $host can either be a string, representing the host, or a stream resource. + * + * @param mixed $host + * @param int $port + * @param int $timeout + * @see self::login() + */ + public function __construct($host, $port = 22, $timeout = 10) + { + if (empty(self::$message_numbers)) { + self::$message_numbers = [ + 1 => 'NET_SSH2_MSG_DISCONNECT', + 2 => 'NET_SSH2_MSG_IGNORE', + 3 => 'NET_SSH2_MSG_UNIMPLEMENTED', + 4 => 'NET_SSH2_MSG_DEBUG', + 5 => 'NET_SSH2_MSG_SERVICE_REQUEST', + 6 => 'NET_SSH2_MSG_SERVICE_ACCEPT', + 7 => 'NET_SSH2_MSG_EXT_INFO', // RFC 8308 + 20 => 'NET_SSH2_MSG_KEXINIT', + 21 => 'NET_SSH2_MSG_NEWKEYS', + 30 => 'NET_SSH2_MSG_KEXDH_INIT', + 31 => 'NET_SSH2_MSG_KEXDH_REPLY', + 50 => 'NET_SSH2_MSG_USERAUTH_REQUEST', + 51 => 'NET_SSH2_MSG_USERAUTH_FAILURE', + 52 => 'NET_SSH2_MSG_USERAUTH_SUCCESS', + 53 => 'NET_SSH2_MSG_USERAUTH_BANNER', + + 80 => 'NET_SSH2_MSG_GLOBAL_REQUEST', + 81 => 'NET_SSH2_MSG_REQUEST_SUCCESS', + 82 => 'NET_SSH2_MSG_REQUEST_FAILURE', + 90 => 'NET_SSH2_MSG_CHANNEL_OPEN', + 91 => 'NET_SSH2_MSG_CHANNEL_OPEN_CONFIRMATION', + 92 => 'NET_SSH2_MSG_CHANNEL_OPEN_FAILURE', + 93 => 'NET_SSH2_MSG_CHANNEL_WINDOW_ADJUST', + 94 => 'NET_SSH2_MSG_CHANNEL_DATA', + 95 => 'NET_SSH2_MSG_CHANNEL_EXTENDED_DATA', + 96 => 'NET_SSH2_MSG_CHANNEL_EOF', + 97 => 'NET_SSH2_MSG_CHANNEL_CLOSE', + 98 => 'NET_SSH2_MSG_CHANNEL_REQUEST', + 99 => 'NET_SSH2_MSG_CHANNEL_SUCCESS', + 100 => 'NET_SSH2_MSG_CHANNEL_FAILURE' + ]; + self::$disconnect_reasons = [ + 1 => 'NET_SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT', + 2 => 'NET_SSH2_DISCONNECT_PROTOCOL_ERROR', + 3 => 'NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED', + 4 => 'NET_SSH2_DISCONNECT_RESERVED', + 5 => 'NET_SSH2_DISCONNECT_MAC_ERROR', + 6 => 'NET_SSH2_DISCONNECT_COMPRESSION_ERROR', + 7 => 'NET_SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE', + 8 => 'NET_SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED', + 9 => 'NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE', + 10 => 'NET_SSH2_DISCONNECT_CONNECTION_LOST', + 11 => 'NET_SSH2_DISCONNECT_BY_APPLICATION', + 12 => 'NET_SSH2_DISCONNECT_TOO_MANY_CONNECTIONS', + 13 => 'NET_SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER', + 14 => 'NET_SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE', + 15 => 'NET_SSH2_DISCONNECT_ILLEGAL_USER_NAME' + ]; + self::$channel_open_failure_reasons = [ + 1 => 'NET_SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED' + ]; + self::$terminal_modes = [ + 0 => 'NET_SSH2_TTY_OP_END' + ]; + self::$channel_extended_data_type_codes = [ + 1 => 'NET_SSH2_EXTENDED_DATA_STDERR' + ]; + + self::define_array( + self::$message_numbers, + self::$disconnect_reasons, + self::$channel_open_failure_reasons, + self::$terminal_modes, + self::$channel_extended_data_type_codes, + [60 => 'NET_SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ'], + [60 => 'NET_SSH2_MSG_USERAUTH_PK_OK'], + [60 => 'NET_SSH2_MSG_USERAUTH_INFO_REQUEST', + 61 => 'NET_SSH2_MSG_USERAUTH_INFO_RESPONSE'], + // RFC 4419 - diffie-hellman-group-exchange-sha{1,256} + [30 => 'NET_SSH2_MSG_KEXDH_GEX_REQUEST_OLD', + 31 => 'NET_SSH2_MSG_KEXDH_GEX_GROUP', + 32 => 'NET_SSH2_MSG_KEXDH_GEX_INIT', + 33 => 'NET_SSH2_MSG_KEXDH_GEX_REPLY', + 34 => 'NET_SSH2_MSG_KEXDH_GEX_REQUEST'], + // RFC 5656 - Elliptic Curves (for [email protected]) + [30 => 'NET_SSH2_MSG_KEX_ECDH_INIT', + 31 => 'NET_SSH2_MSG_KEX_ECDH_REPLY'] + ); + } + + /** + * Typehint is required due to a bug in Psalm: https://github.com/vimeo/psalm/issues/7508 + * @var \WeakReference<SSH2>|SSH2 + */ + self::$connections[$this->getResourceId()] = class_exists('WeakReference') + ? \WeakReference::create($this) + : $this; + + if (is_resource($host)) { + $this->fsock = $host; + return; + } + + if (Strings::is_stringable($host)) { + $this->host = $host; + $this->port = $port; + $this->timeout = $timeout; + } + } + + /** + * Set Crypto Engine Mode + * + * Possible $engine values: + * OpenSSL, mcrypt, Eval, PHP + * + * @param int $engine + */ + public static function setCryptoEngine($engine) + { + self::$crypto_engine = $engine; + } + + /** + * Send Identification String First + * + * https://tools.ietf.org/html/rfc4253#section-4.2 says "when the connection has been established, + * both sides MUST send an identification string". It does not say which side sends it first. In + * theory it shouldn't matter but it is a fact of life that some SSH servers are simply buggy + * + */ + public function sendIdentificationStringFirst() + { + $this->send_id_string_first = true; + } + + /** + * Send Identification String Last + * + * https://tools.ietf.org/html/rfc4253#section-4.2 says "when the connection has been established, + * both sides MUST send an identification string". It does not say which side sends it first. In + * theory it shouldn't matter but it is a fact of life that some SSH servers are simply buggy + * + */ + public function sendIdentificationStringLast() + { + $this->send_id_string_first = false; + } + + /** + * Send SSH_MSG_KEXINIT First + * + * https://tools.ietf.org/html/rfc4253#section-7.1 says "key exchange begins by each sending + * sending the [SSH_MSG_KEXINIT] packet". It does not say which side sends it first. In theory + * it shouldn't matter but it is a fact of life that some SSH servers are simply buggy + * + */ + public function sendKEXINITFirst() + { + $this->send_kex_first = true; + } + + /** + * Send SSH_MSG_KEXINIT Last + * + * https://tools.ietf.org/html/rfc4253#section-7.1 says "key exchange begins by each sending + * sending the [SSH_MSG_KEXINIT] packet". It does not say which side sends it first. In theory + * it shouldn't matter but it is a fact of life that some SSH servers are simply buggy + * + */ + public function sendKEXINITLast() + { + $this->send_kex_first = false; + } + + /** + * stream_select wrapper + * + * Quoting https://stackoverflow.com/a/14262151/569976, + * "The general approach to `EINTR` is to simply handle the error and retry the operation again" + * + * This wrapper does that loop + */ + private static function stream_select(&$read, &$write, &$except, $seconds, $microseconds = null) + { + $remaining = $seconds + $microseconds / 1000000; + $start = microtime(true); + while (true) { + $result = @stream_select($read, $write, $except, $seconds, $microseconds); + if ($result !== false) { + return $result; + } + $elapsed = microtime(true) - $start; + $seconds = (int) ($remaining - floor($elapsed)); + $microseconds = (int) (1000000 * ($remaining - $seconds)); + if ($elapsed >= $remaining) { + return false; + } + } + } + + /** + * Connect to an SSHv2 server + * + * @throws \UnexpectedValueException on receipt of unexpected packets + * @throws \RuntimeException on other errors + */ + private function connect() + { + if ($this->bitmap & self::MASK_CONSTRUCTOR) { + return; + } + + $this->bitmap |= self::MASK_CONSTRUCTOR; + + $this->curTimeout = $this->timeout; + + $this->last_packet = microtime(true); + + if (!is_resource($this->fsock)) { + $start = microtime(true); + // with stream_select a timeout of 0 means that no timeout takes place; + // with fsockopen a timeout of 0 means that you instantly timeout + // to resolve this incompatibility a timeout of 100,000 will be used for fsockopen if timeout is 0 + $this->fsock = @fsockopen($this->host, $this->port, $errno, $errstr, $this->curTimeout == 0 ? 100000 : $this->curTimeout); + if (!$this->fsock) { + $host = $this->host . ':' . $this->port; + throw new UnableToConnectException(rtrim("Cannot connect to $host. Error $errno. $errstr")); + } + $elapsed = microtime(true) - $start; + + if ($this->curTimeout) { + $this->curTimeout -= $elapsed; + if ($this->curTimeout < 0) { + throw new \RuntimeException('Connection timed out whilst attempting to open socket connection'); + } + } + } + + $this->identifier = $this->generate_identifier(); + + if ($this->send_id_string_first) { + fputs($this->fsock, $this->identifier . "\r\n"); + } + + /* According to the SSH2 specs, + + "The server MAY send other lines of data before sending the version + string. Each line SHOULD be terminated by a Carriage Return and Line + Feed. Such lines MUST NOT begin with "SSH-", and SHOULD be encoded + in ISO-10646 UTF-8 [RFC3629] (language is not specified). Clients + MUST be able to process such lines." */ + $data = ''; + while (!feof($this->fsock) && !preg_match('#(.*)^(SSH-(\d\.\d+).*)#ms', $data, $matches)) { + $line = ''; + while (true) { + if ($this->curTimeout) { + if ($this->curTimeout < 0) { + throw new \RuntimeException('Connection timed out whilst receiving server identification string'); + } + $read = [$this->fsock]; + $write = $except = null; + $start = microtime(true); + $sec = (int) floor($this->curTimeout); + $usec = (int) (1000000 * ($this->curTimeout - $sec)); + if (static::stream_select($read, $write, $except, $sec, $usec) === false) { + throw new \RuntimeException('Connection timed out whilst receiving server identification string'); + } + $elapsed = microtime(true) - $start; + $this->curTimeout -= $elapsed; + } + + $temp = stream_get_line($this->fsock, 255, "\n"); + if ($temp === false) { + throw new \RuntimeException('Error reading from socket'); + } + if (strlen($temp) == 255) { + continue; + } + + $line .= "$temp\n"; + + // quoting RFC4253, "Implementers who wish to maintain + // compatibility with older, undocumented versions of this protocol may + // want to process the identification string without expecting the + // presence of the carriage return character for reasons described in + // Section 5 of this document." + + //if (substr($line, -2) == "\r\n") { + // break; + //} + + break; + } + + $data .= $line; + } + + if (feof($this->fsock)) { + $this->bitmap = 0; + throw new ConnectionClosedException('Connection closed by server'); + } + + $extra = $matches[1]; + + if (defined('NET_SSH2_LOGGING')) { + $this->append_log('<-', $matches[0]); + $this->append_log('->', $this->identifier . "\r\n"); + } + + $this->server_identifier = trim($temp, "\r\n"); + if (strlen($extra)) { + $this->errors[] = $data; + } + + if (version_compare($matches[3], '1.99', '<')) { + $this->bitmap = 0; + throw new UnableToConnectException("Cannot connect to SSH $matches[3] servers"); + } + + // Ubuntu's OpenSSH from 5.8 to 6.9 didn't work with multiple channels. see + // https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/1334916 for more info. + // https://lists.ubuntu.com/archives/oneiric-changes/2011-July/005772.html discusses + // when consolekit was incorporated. + // https://marc.info/?l=openssh-unix-dev&m=163409903417589&w=2 discusses some of the + // issues with how Ubuntu incorporated consolekit + $pattern = '#^SSH-2\.0-OpenSSH_([\d.]+)[^ ]* Ubuntu-.*$#'; + $match = preg_match($pattern, $this->server_identifier, $matches); + $match = $match && version_compare('5.8', $matches[1], '<='); + $match = $match && version_compare('6.9', $matches[1], '>='); + $this->errorOnMultipleChannels = $match; + + if (!$this->send_id_string_first) { + fputs($this->fsock, $this->identifier . "\r\n"); + } + + if (!$this->send_kex_first) { + $response = $this->get_binary_packet(); + + if (is_bool($response) || !strlen($response) || ord($response[0]) != NET_SSH2_MSG_KEXINIT) { + $this->bitmap = 0; + throw new \UnexpectedValueException('Expected SSH_MSG_KEXINIT'); + } + + $this->key_exchange($response); + } + + if ($this->send_kex_first) { + $this->key_exchange(); + } + + $this->bitmap |= self::MASK_CONNECTED; + + return true; + } + + /** + * Generates the SSH identifier + * + * You should overwrite this method in your own class if you want to use another identifier + * + * @return string + */ + private function generate_identifier() + { + $identifier = 'SSH-2.0-phpseclib_3.0'; + + $ext = []; + if (extension_loaded('sodium')) { + $ext[] = 'libsodium'; + } + + if (extension_loaded('openssl')) { + $ext[] = 'openssl'; + } elseif (extension_loaded('mcrypt')) { + $ext[] = 'mcrypt'; + } + + if (extension_loaded('gmp')) { + $ext[] = 'gmp'; + } elseif (extension_loaded('bcmath')) { + $ext[] = 'bcmath'; + } + + if (!empty($ext)) { + $identifier .= ' (' . implode(', ', $ext) . ')'; + } + + return $identifier; + } + + /** + * Key Exchange + * + * @return bool + * @param string|bool $kexinit_payload_server optional + * @throws \UnexpectedValueException on receipt of unexpected packets + * @throws \RuntimeException on other errors + * @throws \phpseclib3\Exception\NoSupportedAlgorithmsException when none of the algorithms phpseclib has loaded are compatible + */ + private function key_exchange($kexinit_payload_server = false) + { + $preferred = $this->preferred; + $send_kex = true; + + $kex_algorithms = isset($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(); + + $kex_algorithms = array_merge($kex_algorithms, ['ext-info-c', '[email protected]']); + + // 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': + 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( + $c2s_mac_algorithms, + ['hmac-sha1-96', 'hmac-md5-96'] + )); + } + break; + case substr($this->server_identifier, 0, 24) == 'SSH-2.0-TurboFTP_SERVER_': + if (!isset($preferred['server_to_client']['crypt'])) { + $s2c_encryption_algorithms = array_values(array_diff( + $s2c_encryption_algorithms, + ['[email protected]', '[email protected]'] + )); + } + if (!isset($preferred['client_to_server']['crypt'])) { + $c2s_encryption_algorithms = array_values(array_diff( + $c2s_encryption_algorithms, + ['[email protected]', '[email protected]'] + )); + } + } + + $client_cookie = Random::string(16); + + $kexinit_payload_client = pack('Ca*', NET_SSH2_MSG_KEXINIT, $client_cookie); + $kexinit_payload_client .= Strings::packSSH2( + 'L10bN', + $kex_algorithms, + $server_host_key_algorithms, + $c2s_encryption_algorithms, + $s2c_encryption_algorithms, + $c2s_mac_algorithms, + $s2c_mac_algorithms, + $c2s_compression_algorithms, + $s2c_compression_algorithms, + [], // language, client to server + [], // language, server to client + false, // first_kex_packet_follows + 0 // reserved for future extension + ); + + if ($kexinit_payload_server === false) { + $this->send_binary_packet($kexinit_payload_client); + + $this->extra_packets = 0; + $kexinit_payload_server = $this->get_binary_packet(); + + if ( + is_bool($kexinit_payload_server) + || !strlen($kexinit_payload_server) + || ord($kexinit_payload_server[0]) != NET_SSH2_MSG_KEXINIT + ) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_PROTOCOL_ERROR); + throw new \UnexpectedValueException('Expected SSH_MSG_KEXINIT'); + } + + $send_kex = false; + } + + $response = $kexinit_payload_server; + Strings::shift($response, 1); // skip past the message number (it should be SSH_MSG_KEXINIT) + $server_cookie = Strings::shift($response, 16); + + list( + $this->kex_algorithms, + $this->server_host_key_algorithms, + $this->encryption_algorithms_client_to_server, + $this->encryption_algorithms_server_to_client, + $this->mac_algorithms_client_to_server, + $this->mac_algorithms_server_to_client, + $this->compression_algorithms_client_to_server, + $this->compression_algorithms_server_to_client, + $this->languages_client_to_server, + $this->languages_server_to_client, + $first_kex_packet_follows + ) = Strings::unpackSSH2('L10C', $response); + if (in_array('[email protected]', $this->kex_algorithms)) { + if ($this->session_id === false && $this->extra_packets) { + throw new \UnexpectedValueException('Possible Terrapin Attack detected'); + } + } + + $this->supported_private_key_algorithms = $this->server_host_key_algorithms; + + if ($send_kex) { + $this->send_binary_packet($kexinit_payload_client); + } + + // 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 + $decrypt = self::array_intersect_first($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'); + } + + $encrypt = self::array_intersect_first($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); + throw new NoSupportedAlgorithmsException('No compatible client to server encryption algorithms found'); + } + + // through diffie-hellman key exchange a symmetric key is obtained + $this->kex_algorithm = self::array_intersect_first($kex_algorithms, $this->kex_algorithms); + if ($this->kex_algorithm === false) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED); + throw new NoSupportedAlgorithmsException('No compatible key exchange algorithms found'); + } + + $server_host_key_algorithm = self::array_intersect_first($server_host_key_algorithms, $this->server_host_key_algorithms); + if ($server_host_key_algorithm === false) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED); + throw new NoSupportedAlgorithmsException('No compatible server host key algorithms found'); + } + + $mac_algorithm_out = self::array_intersect_first($c2s_mac_algorithms, $this->mac_algorithms_client_to_server); + if ($mac_algorithm_out === false) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED); + throw new NoSupportedAlgorithmsException('No compatible client to server message authentication algorithms found'); + } + + $mac_algorithm_in = self::array_intersect_first($s2c_mac_algorithms, $this->mac_algorithms_server_to_client); + if ($mac_algorithm_in === false) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED); + throw new NoSupportedAlgorithmsException('No compatible server to client message authentication algorithms found'); + } + + $compression_map = [ + 'none' => self::NET_SSH2_COMPRESSION_NONE, + 'zlib' => self::NET_SSH2_COMPRESSION_ZLIB, + '[email protected]' => self::NET_SSH2_COMPRESSION_ZLIB_AT_OPENSSH + ]; + + $compression_algorithm_in = self::array_intersect_first($s2c_compression_algorithms, $this->compression_algorithms_server_to_client); + if ($compression_algorithm_in === false) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED); + throw new NoSupportedAlgorithmsException('No compatible server to client compression algorithms found'); + } + $this->decompress = $compression_map[$compression_algorithm_in]; + + $compression_algorithm_out = self::array_intersect_first($c2s_compression_algorithms, $this->compression_algorithms_client_to_server); + if ($compression_algorithm_out === false) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED); + throw new NoSupportedAlgorithmsException('No compatible client to server compression algorithms found'); + } + $this->compress = $compression_map[$compression_algorithm_out]; + + switch ($this->kex_algorithm) { + case 'diffie-hellman-group15-sha512': + case 'diffie-hellman-group16-sha512': + case 'diffie-hellman-group17-sha512': + case 'diffie-hellman-group18-sha512': + case 'ecdh-sha2-nistp521': + $kexHash = new Hash('sha512'); + break; + case 'ecdh-sha2-nistp384': + $kexHash = new Hash('sha384'); + break; + case 'diffie-hellman-group-exchange-sha256': + case 'diffie-hellman-group14-sha256': + case 'ecdh-sha2-nistp256': + case '[email protected]': + case 'curve25519-sha256': + $kexHash = new Hash('sha256'); + break; + default: + $kexHash = new Hash('sha1'); + } + + // Only relevant in diffie-hellman-group-exchange-sha{1,256}, otherwise empty. + + $exchange_hash_rfc4419 = ''; + + if (strpos($this->kex_algorithm, 'curve25519-sha256') === 0 || strpos($this->kex_algorithm, 'ecdh-sha2-nistp') === 0) { + $curve = strpos($this->kex_algorithm, 'curve25519-sha256') === 0 ? + 'Curve25519' : + substr($this->kex_algorithm, 10); + $ourPrivate = EC::createKey($curve); + $ourPublicBytes = $ourPrivate->getPublicKey()->getEncodedCoordinates(); + $clientKexInitMessage = 'NET_SSH2_MSG_KEX_ECDH_INIT'; + $serverKexReplyMessage = 'NET_SSH2_MSG_KEX_ECDH_REPLY'; + } else { + if (strpos($this->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 + ); + $this->send_binary_packet($packet); + $this->updateLogHistory('UNKNOWN (34)', 'NET_SSH2_MSG_KEXDH_GEX_REQUEST'); + + $response = $this->get_binary_packet(); + + list($type, $primeBytes, $gBytes) = Strings::unpackSSH2('Css', $response); + if ($type != NET_SSH2_MSG_KEXDH_GEX_GROUP) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_PROTOCOL_ERROR); + throw new \UnexpectedValueException('Expected SSH_MSG_KEX_DH_GEX_GROUP'); + } + $this->updateLogHistory('NET_SSH2_MSG_KEXDH_REPLY', 'NET_SSH2_MSG_KEXDH_GEX_GROUP'); + $prime = new BigInteger($primeBytes, -256); + $g = new BigInteger($gBytes, -256); + + $exchange_hash_rfc4419 = $dh_group_sizes_packed . Strings::packSSH2( + 'ss', + $primeBytes, + $gBytes + ); + + $params = DH::createParameters($prime, $g); + $clientKexInitMessage = 'NET_SSH2_MSG_KEXDH_GEX_INIT'; + $serverKexReplyMessage = 'NET_SSH2_MSG_KEXDH_GEX_REPLY'; + } else { + $params = DH::createParameters($this->kex_algorithm); + $clientKexInitMessage = 'NET_SSH2_MSG_KEXDH_INIT'; + $serverKexReplyMessage = 'NET_SSH2_MSG_KEXDH_REPLY'; + } + + $keyLength = min($kexHash->getLengthInBytes(), max($encryptKeyLength, $decryptKeyLength)); + + $ourPrivate = DH::createKey($params, 16 * $keyLength); // 2 * 8 * $keyLength + $ourPublic = $ourPrivate->getPublicKey()->toBigInteger(); + $ourPublicBytes = $ourPublic->toBytes(true); + } + + $data = pack('CNa*', constant($clientKexInitMessage), strlen($ourPublicBytes), $ourPublicBytes); + + $this->send_binary_packet($data); + + switch ($clientKexInitMessage) { + case 'NET_SSH2_MSG_KEX_ECDH_INIT': + $this->updateLogHistory('NET_SSH2_MSG_KEXDH_INIT', 'NET_SSH2_MSG_KEX_ECDH_INIT'); + break; + case 'NET_SSH2_MSG_KEXDH_GEX_INIT': + $this->updateLogHistory('UNKNOWN (32)', 'NET_SSH2_MSG_KEXDH_GEX_INIT'); + } + + $response = $this->get_binary_packet(); + + list( + $type, + $server_public_host_key, + $theirPublicBytes, + $this->signature + ) = Strings::unpackSSH2('Csss', $response); + + if ($type != constant($serverKexReplyMessage)) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_PROTOCOL_ERROR); + throw new \UnexpectedValueException("Expected $serverKexReplyMessage"); + } + switch ($serverKexReplyMessage) { + case 'NET_SSH2_MSG_KEX_ECDH_REPLY': + $this->updateLogHistory('NET_SSH2_MSG_KEXDH_REPLY', 'NET_SSH2_MSG_KEX_ECDH_REPLY'); + break; + case 'NET_SSH2_MSG_KEXDH_GEX_REPLY': + $this->updateLogHistory('UNKNOWN (33)', 'NET_SSH2_MSG_KEXDH_GEX_REPLY'); + } + + $this->server_public_host_key = $server_public_host_key; + list($public_key_format) = Strings::unpackSSH2('s', $server_public_host_key); + if (strlen($this->signature) < 4) { + throw new \LengthException('The signature needs at least four bytes'); + } + $temp = unpack('Nlength', substr($this->signature, 0, 4)); + $this->signature_format = substr($this->signature, 4, $temp['length']); + + $keyBytes = DH::computeSecret($ourPrivate, $theirPublicBytes); + if (($keyBytes & "\xFF\x80") === "\x00\x00") { + $keyBytes = substr($keyBytes, 1); + } elseif (($keyBytes[0] & "\x80") === "\x80") { + $keyBytes = "\0$keyBytes"; + } + + $this->exchange_hash = Strings::packSSH2( + 's5', + $this->identifier, + $this->server_identifier, + $kexinit_payload_client, + $kexinit_payload_server, + $this->server_public_host_key + ); + $this->exchange_hash .= $exchange_hash_rfc4419; + $this->exchange_hash .= Strings::packSSH2( + 's3', + $ourPublicBytes, + $theirPublicBytes, + $keyBytes + ); + + $this->exchange_hash = $kexHash->hash($this->exchange_hash); + + if ($this->session_id === false) { + $this->session_id = $this->exchange_hash; + } + + switch ($server_host_key_algorithm) { + case 'rsa-sha2-256': + case 'rsa-sha2-512': + //case 'ssh-rsa': + $expected_key_format = 'ssh-rsa'; + break; + default: + $expected_key_format = $server_host_key_algorithm; + } + if ($public_key_format != $expected_key_format || $this->signature_format != $server_host_key_algorithm) { + switch (true) { + case $this->signature_format == $server_host_key_algorithm: + case $server_host_key_algorithm != 'rsa-sha2-256' && $server_host_key_algorithm != 'rsa-sha2-512': + case $this->signature_format != 'ssh-rsa': + $this->disconnect_helper(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE); + throw new \RuntimeException('Server Host Key Algorithm Mismatch (' . $this->signature_format . ' vs ' . $server_host_key_algorithm . ')'); + } + } + + $packet = pack('C', NET_SSH2_MSG_NEWKEYS); + $this->send_binary_packet($packet); + + $response = $this->get_binary_packet(); + + if ($response === false) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_CONNECTION_LOST); + throw new ConnectionClosedException('Connection closed by server'); + } + + list($type) = Strings::unpackSSH2('C', $response); + if ($type != NET_SSH2_MSG_NEWKEYS) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_PROTOCOL_ERROR); + throw new \UnexpectedValueException('Expected SSH_MSG_NEWKEYS'); + } + + if (in_array('[email protected]', $this->kex_algorithms)) { + $this->get_seq_no = $this->send_seq_no = 0; + } + + $keyBytes = pack('Na*', strlen($keyBytes), $keyBytes); + + $this->encrypt = self::encryption_algorithm_to_crypt_instance($encrypt); + if ($this->encrypt) { + if (self::$crypto_engine) { + $this->encrypt->setPreferredEngine(self::$crypto_engine); + } + if ($this->encrypt->getBlockLengthInBytes()) { + $this->encrypt_block_size = $this->encrypt->getBlockLengthInBytes(); + } + $this->encrypt->disablePadding(); + + if ($this->encrypt->usesIV()) { + $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, $this->encrypt_block_size)); + } + + switch ($encrypt) { + case '[email protected]': + case '[email protected]': + $nonce = $kexHash->hash($keyBytes . $this->exchange_hash . 'A' . $this->session_id); + $this->encryptFixedPart = substr($nonce, 0, 4); + $this->encryptInvocationCounter = substr($nonce, 4, 8); + // fall-through + case '[email protected]': + break; + default: + $this->encrypt->enableContinuousBuffer(); + } + + $key = $kexHash->hash($keyBytes . $this->exchange_hash . 'C' . $this->session_id); + while ($encryptKeyLength > strlen($key)) { + $key .= $kexHash->hash($keyBytes . $this->exchange_hash . $key); + } + switch ($encrypt) { + case '[email protected]': + $encryptKeyLength = 32; + $this->lengthEncrypt = self::encryption_algorithm_to_crypt_instance($encrypt); + $this->lengthEncrypt->setKey(substr($key, 32, 32)); + } + $this->encrypt->setKey(substr($key, 0, $encryptKeyLength)); + $this->encryptName = $encrypt; + } + + $this->decrypt = self::encryption_algorithm_to_crypt_instance($decrypt); + if ($this->decrypt) { + if (self::$crypto_engine) { + $this->decrypt->setPreferredEngine(self::$crypto_engine); + } + if ($this->decrypt->getBlockLengthInBytes()) { + $this->decrypt_block_size = $this->decrypt->getBlockLengthInBytes(); + } + $this->decrypt->disablePadding(); + + if ($this->decrypt->usesIV()) { + $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, $this->decrypt_block_size)); + } + + switch ($decrypt) { + case '[email protected]': + case '[email protected]': + // see https://tools.ietf.org/html/rfc5647#section-7.1 + $nonce = $kexHash->hash($keyBytes . $this->exchange_hash . 'B' . $this->session_id); + $this->decryptFixedPart = substr($nonce, 0, 4); + $this->decryptInvocationCounter = substr($nonce, 4, 8); + // fall-through + case '[email protected]': + break; + default: + $this->decrypt->enableContinuousBuffer(); + } + + $key = $kexHash->hash($keyBytes . $this->exchange_hash . 'D' . $this->session_id); + while ($decryptKeyLength > strlen($key)) { + $key .= $kexHash->hash($keyBytes . $this->exchange_hash . $key); + } + switch ($decrypt) { + case '[email protected]': + $decryptKeyLength = 32; + $this->lengthDecrypt = self::encryption_algorithm_to_crypt_instance($decrypt); + $this->lengthDecrypt->setKey(substr($key, 32, 32)); + } + $this->decrypt->setKey(substr($key, 0, $decryptKeyLength)); + $this->decryptName = $decrypt; + } + + /* The "arcfour128" algorithm is the RC4 cipher, as described in + [SCHNEIER], using a 128-bit key. The first 1536 bytes of keystream + generated by the cipher MUST be discarded, and the first byte of the + first encrypted packet MUST be encrypted using the 1537th byte of + keystream. + + -- http://tools.ietf.org/html/rfc4345#section-4 */ + if ($encrypt == 'arcfour128' || $encrypt == 'arcfour256') { + $this->encrypt->encrypt(str_repeat("\0", 1536)); + } + if ($decrypt == 'arcfour128' || $decrypt == 'arcfour256') { + $this->decrypt->decrypt(str_repeat("\0", 1536)); + } + + if (!$this->encrypt->usesNonce()) { + list($this->hmac_create, $createKeyLength) = self::mac_algorithm_to_hash_instance($mac_algorithm_out); + } else { + $this->hmac_create = new \stdClass(); + $this->hmac_create_name = $mac_algorithm_out; + //$mac_algorithm_out = 'none'; + $createKeyLength = 0; + } + + if ($this->hmac_create instanceof Hash) { + $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)); + $this->hmac_create_name = $mac_algorithm_out; + $this->hmac_create_etm = preg_match('#-etm@openssh\.com$#', $mac_algorithm_out); + } + + if (!$this->decrypt->usesNonce()) { + list($this->hmac_check, $checkKeyLength) = self::mac_algorithm_to_hash_instance($mac_algorithm_in); + $this->hmac_size = $this->hmac_check->getLengthInBytes(); + } else { + $this->hmac_check = new \stdClass(); + $this->hmac_check_name = $mac_algorithm_in; + //$mac_algorithm_in = 'none'; + $checkKeyLength = 0; + $this->hmac_size = 0; + } + + if ($this->hmac_check instanceof Hash) { + $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)); + $this->hmac_check_name = $mac_algorithm_in; + $this->hmac_check_etm = preg_match('#-etm@openssh\.com$#', $mac_algorithm_in); + } + + $this->regenerate_compression_context = $this->regenerate_decompression_context = true; + + return true; + } + + /** + * Maps an encryption algorithm name to the number of key bytes. + * + * @param string $algorithm Name of the encryption algorithm + * @return int|null Number of bytes as an integer or null for unknown + */ + private function encryption_algorithm_to_key_size($algorithm) + { + if ($this->bad_key_size_fix && self::bad_algorithm_candidate($algorithm)) { + return 16; + } + + switch ($algorithm) { + case 'none': + return 0; + case '[email protected]': + case 'aes128-cbc': + case 'aes128-ctr': + case 'arcfour': + case 'arcfour128': + case 'blowfish-cbc': + case 'blowfish-ctr': + case 'twofish128-cbc': + case 'twofish128-ctr': + return 16; + case '3des-cbc': + case '3des-ctr': + case 'aes192-cbc': + case 'aes192-ctr': + case 'twofish192-cbc': + case 'twofish192-ctr': + return 24; + case '[email protected]': + case 'aes256-cbc': + case 'aes256-ctr': + case 'arcfour256': + case 'twofish-cbc': + case 'twofish256-cbc': + case 'twofish256-ctr': + return 32; + case '[email protected]': + return 64; + } + return null; + } + + /** + * Maps an encryption algorithm name to an instance of a subclass of + * \phpseclib3\Crypt\Common\SymmetricKey. + * + * @param string $algorithm Name of the encryption algorithm + * @return SymmetricKey|null + */ + private static function encryption_algorithm_to_crypt_instance($algorithm) + { + switch ($algorithm) { + case '3des-cbc': + return new TripleDES('cbc'); + case '3des-ctr': + return new TripleDES('ctr'); + case 'aes256-cbc': + case 'aes192-cbc': + case 'aes128-cbc': + return new Rijndael('cbc'); + case 'aes256-ctr': + case 'aes192-ctr': + case 'aes128-ctr': + return new Rijndael('ctr'); + case 'blowfish-cbc': + return new Blowfish('cbc'); + case 'blowfish-ctr': + return new Blowfish('ctr'); + case 'twofish128-cbc': + case 'twofish192-cbc': + case 'twofish256-cbc': + case 'twofish-cbc': + return new Twofish('cbc'); + case 'twofish128-ctr': + case 'twofish192-ctr': + case 'twofish256-ctr': + return new Twofish('ctr'); + case 'arcfour': + case 'arcfour128': + case 'arcfour256': + return new RC4(); + case '[email protected]': + case '[email protected]': + return new Rijndael('gcm'); + case '[email protected]': + return new ChaCha20(); + } + return null; + } + + /** + * Maps an encryption algorithm name to an instance of a subclass of + * \phpseclib3\Crypt\Hash. + * + * @param string $algorithm Name of the encryption algorithm + * @return array{Hash, int}|null + */ + private static function mac_algorithm_to_hash_instance($algorithm) + { + switch ($algorithm) { + case '[email protected]': + case '[email protected]': + return [new Hash('umac-64'), 16]; + case '[email protected]': + case '[email protected]': + return [new Hash('umac-128'), 16]; + case 'hmac-sha2-512': + case '[email protected]': + return [new Hash('sha512'), 64]; + case 'hmac-sha2-256': + case '[email protected]': + return [new Hash('sha256'), 32]; + case 'hmac-sha1': + case '[email protected]': + return [new Hash('sha1'), 20]; + case 'hmac-sha1-96': + return [new Hash('sha1-96'), 20]; + case 'hmac-md5': + return [new Hash('md5'), 16]; + case 'hmac-md5-96': + return [new Hash('md5-96'), 16]; + } + } + + /* + * Tests whether or not proposed algorithm has a potential for issues + * + * @link https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/ssh2-aesctr-openssh.html + * @link https://bugzilla.mindrot.org/show_bug.cgi?id=1291 + * @param string $algorithm Name of the encryption algorithm + * @return bool + */ + private static function bad_algorithm_candidate($algorithm) + { + switch ($algorithm) { + case 'arcfour256': + case 'aes192-ctr': + case 'aes256-ctr': + return true; + } + + return false; + } + + /** + * Login + * + * The $password parameter can be a plaintext password, a \phpseclib3\Crypt\RSA|EC|DSA object, a \phpseclib3\System\SSH\Agent object or an array + * + * @param string $username + * @param string|PrivateKey|array[]|Agent|null ...$args + * @return bool + * @see self::_login() + */ + public function login($username, ...$args) + { + if (!$this->retry_connect) { + $this->auth[] = func_get_args(); + } + + // try logging with 'none' as an authentication method first since that's what + // PuTTY does + if (substr($this->server_identifier, 0, 15) != 'SSH-2.0-CoreFTP' && $this->auth_methods_to_continue === null) { + if ($this->sublogin($username)) { + return true; + } + if (!count($args)) { + return false; + } + } + return $this->sublogin($username, ...$args); + } + + /** + * Login Helper + * + * @param string $username + * @param string|PrivateKey|array[]|Agent|null ...$args + * @return bool + * @see self::_login_helper() + */ + protected function sublogin($username, ...$args) + { + if (!($this->bitmap & self::MASK_CONSTRUCTOR)) { + $this->connect(); + } + + if (empty($args)) { + return $this->login_helper($username); + } + + foreach ($args as $arg) { + switch (true) { + case $arg instanceof PublicKey: + throw new \UnexpectedValueException('A PublicKey object was passed to the login method instead of a PrivateKey object'); + case $arg instanceof PrivateKey: + case $arg instanceof Agent: + case is_array($arg): + case Strings::is_stringable($arg): + break; + default: + throw new \UnexpectedValueException('$password needs to either be an instance of \phpseclib3\Crypt\Common\PrivateKey, \System\SSH\Agent, an array or a string'); + } + } + + while (count($args)) { + if (!$this->auth_methods_to_continue || !$this->smartMFA) { + $newargs = $args; + $args = []; + } else { + $newargs = []; + foreach ($this->auth_methods_to_continue as $method) { + switch ($method) { + case 'publickey': + foreach ($args as $key => $arg) { + if ($arg instanceof PrivateKey || $arg instanceof Agent) { + $newargs[] = $arg; + unset($args[$key]); + break; + } + } + break; + case 'keyboard-interactive': + $hasArray = $hasString = false; + foreach ($args as $arg) { + if ($hasArray || is_array($arg)) { + $hasArray = true; + break; + } + if ($hasString || Strings::is_stringable($arg)) { + $hasString = true; + break; + } + } + if ($hasArray && $hasString) { + foreach ($args as $key => $arg) { + if (is_array($arg)) { + $newargs[] = $arg; + break 2; + } + } + } + // fall-through + case 'password': + foreach ($args as $key => $arg) { + $newargs[] = $arg; + unset($args[$key]); + break; + } + } + } + } + + if (!count($newargs)) { + return false; + } + + foreach ($newargs as $arg) { + if ($this->login_helper($username, $arg)) { + return true; + } + } + } + return false; + } + + /** + * Login Helper + * + * {@internal It might be worthwhile, at some point, to protect against {@link http://tools.ietf.org/html/rfc4251#section-9.3.9 traffic analysis} + * by sending dummy SSH_MSG_IGNORE messages.} + * + * @param string $username + * @param string|AsymmetricKey|array[]|Agent|null ...$args + * @return bool + * @throws \UnexpectedValueException on receipt of unexpected packets + * @throws \RuntimeException on other errors + */ + private function login_helper($username, $password = null) + { + if (!($this->bitmap & self::MASK_CONNECTED)) { + return false; + } + + if (!($this->bitmap & self::MASK_LOGIN_REQ)) { + $packet = Strings::packSSH2('Cs', NET_SSH2_MSG_SERVICE_REQUEST, 'ssh-userauth'); + $this->send_binary_packet($packet); + + try { + $response = $this->get_binary_packet(); + } catch (\Exception $e) { + if ($this->retry_connect) { + $this->retry_connect = false; + $this->connect(); + return $this->login_helper($username, $password); + } + $this->disconnect_helper(NET_SSH2_DISCONNECT_CONNECTION_LOST); + throw $e; + } + + list($type) = Strings::unpackSSH2('C', $response); + + if ($type == NET_SSH2_MSG_EXT_INFO) { + list($nr_extensions) = Strings::unpackSSH2('N', $response); + for ($i = 0; $i < $nr_extensions; $i++) { + list($extension_name, $extension_value) = Strings::unpackSSH2('ss', $response); + if ($extension_name == 'server-sig-algs') { + $this->supported_private_key_algorithms = explode(',', $extension_value); + } + } + + $response = $this->get_binary_packet(); + list($type) = Strings::unpackSSH2('C', $response); + } + + list($service) = Strings::unpackSSH2('s', $response); + + if ($type != NET_SSH2_MSG_SERVICE_ACCEPT || $service != 'ssh-userauth') { + $this->disconnect_helper(NET_SSH2_DISCONNECT_PROTOCOL_ERROR); + throw new \UnexpectedValueException('Expected SSH_MSG_SERVICE_ACCEPT'); + } + $this->bitmap |= self::MASK_LOGIN_REQ; + } + + if (strlen($this->last_interactive_response)) { + return !Strings::is_stringable($password) && !is_array($password) ? false : $this->keyboard_interactive_process($password); + } + + if ($password instanceof PrivateKey) { + return $this->privatekey_login($username, $password); + } + + if ($password instanceof Agent) { + return $this->ssh_agent_login($username, $password); + } + + if (is_array($password)) { + if ($this->keyboard_interactive_login($username, $password)) { + $this->bitmap |= self::MASK_LOGIN; + return true; + } + return false; + } + + if (!isset($password)) { + $packet = Strings::packSSH2( + 'Cs3', + NET_SSH2_MSG_USERAUTH_REQUEST, + $username, + 'ssh-connection', + 'none' + ); + + $this->send_binary_packet($packet); + + $response = $this->get_binary_packet(); + + list($type) = Strings::unpackSSH2('C', $response); + switch ($type) { + case NET_SSH2_MSG_USERAUTH_SUCCESS: + $this->bitmap |= self::MASK_LOGIN; + return true; + case NET_SSH2_MSG_USERAUTH_FAILURE: + list($auth_methods) = Strings::unpackSSH2('L', $response); + $this->auth_methods_to_continue = $auth_methods; + // fall-through + default: + return false; + } + } + + $packet = Strings::packSSH2( + 'Cs3bs', + NET_SSH2_MSG_USERAUTH_REQUEST, + $username, + 'ssh-connection', + 'password', + false, + $password + ); + + // remove the username and password from the logged packet + if (!defined('NET_SSH2_LOGGING')) { + $logged = null; + } else { + $logged = Strings::packSSH2( + 'Cs3bs', + NET_SSH2_MSG_USERAUTH_REQUEST, + $username, + 'ssh-connection', + 'password', + false, + 'password' + ); + } + + $this->send_binary_packet($packet, $logged); + + $response = $this->get_binary_packet(); + if ($response === false) { + return false; + } + list($type) = Strings::unpackSSH2('C', $response); + switch ($type) { + case NET_SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: // in theory, the password can be changed + $this->updateLogHistory('UNKNOWN (60)', 'NET_SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ'); + + list($message) = Strings::unpackSSH2('s', $response); + $this->errors[] = 'SSH_MSG_USERAUTH_PASSWD_CHANGEREQ: ' . $message; + + return $this->disconnect_helper(NET_SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER); + case NET_SSH2_MSG_USERAUTH_FAILURE: + // can we use keyboard-interactive authentication? if not then either the login is bad or the server employees + // multi-factor authentication + list($auth_methods, $partial_success) = Strings::unpackSSH2('Lb', $response); + $this->auth_methods_to_continue = $auth_methods; + if (!$partial_success && in_array('keyboard-interactive', $auth_methods)) { + if ($this->keyboard_interactive_login($username, $password)) { + $this->bitmap |= self::MASK_LOGIN; + return true; + } + return false; + } + return false; + case NET_SSH2_MSG_USERAUTH_SUCCESS: + $this->bitmap |= self::MASK_LOGIN; + return true; + } + + return false; + } + + /** + * Login via keyboard-interactive authentication + * + * See {@link http://tools.ietf.org/html/rfc4256 RFC4256} for details. This is not a full-featured keyboard-interactive authenticator. + * + * @param string $username + * @param string|array $password + * @return bool + */ + private function keyboard_interactive_login($username, $password) + { + $packet = Strings::packSSH2( + 'Cs5', + NET_SSH2_MSG_USERAUTH_REQUEST, + $username, + 'ssh-connection', + 'keyboard-interactive', + '', // language tag + '' // submethods + ); + $this->send_binary_packet($packet); + + return $this->keyboard_interactive_process($password); + } + + /** + * Handle the keyboard-interactive requests / responses. + * + * @param string|array ...$responses + * @return bool + * @throws \RuntimeException on connection error + */ + private function keyboard_interactive_process(...$responses) + { + if (strlen($this->last_interactive_response)) { + $response = $this->last_interactive_response; + } else { + $orig = $response = $this->get_binary_packet(); + } + + list($type) = Strings::unpackSSH2('C', $response); + switch ($type) { + case NET_SSH2_MSG_USERAUTH_INFO_REQUEST: + list( + , // name; may be empty + , // instruction; may be empty + , // language tag; may be empty + $num_prompts + ) = Strings::unpackSSH2('s3N', $response); + + for ($i = 0; $i < count($responses); $i++) { + if (is_array($responses[$i])) { + foreach ($responses[$i] as $key => $value) { + $this->keyboard_requests_responses[$key] = $value; + } + unset($responses[$i]); + } + } + $responses = array_values($responses); + + if (isset($this->keyboard_requests_responses)) { + for ($i = 0; $i < $num_prompts; $i++) { + list( + $prompt, // prompt - ie. "Password: "; must not be empty + // echo + ) = Strings::unpackSSH2('sC', $response); + foreach ($this->keyboard_requests_responses as $key => $value) { + if (substr($prompt, 0, strlen($key)) == $key) { + $responses[] = $value; + break; + } + } + } + } + + // see http://tools.ietf.org/html/rfc4256#section-3.2 + if (strlen($this->last_interactive_response)) { + $this->last_interactive_response = ''; + } else { + $this->updateLogHistory('UNKNOWN (60)', 'NET_SSH2_MSG_USERAUTH_INFO_REQUEST'); + } + + if (!count($responses) && $num_prompts) { + $this->last_interactive_response = $orig; + return false; + } + + /* + After obtaining the requested information from the user, the client + MUST respond with an SSH_MSG_USERAUTH_INFO_RESPONSE message. + */ + // see http://tools.ietf.org/html/rfc4256#section-3.4 + $packet = $logged = pack('CN', NET_SSH2_MSG_USERAUTH_INFO_RESPONSE, count($responses)); + for ($i = 0; $i < count($responses); $i++) { + $packet .= Strings::packSSH2('s', $responses[$i]); + $logged .= Strings::packSSH2('s', 'dummy-answer'); + } + + $this->send_binary_packet($packet, $logged); + + $this->updateLogHistory('UNKNOWN (61)', 'NET_SSH2_MSG_USERAUTH_INFO_RESPONSE'); + + /* + After receiving the response, the server MUST send either an + SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, or another + SSH_MSG_USERAUTH_INFO_REQUEST message. + */ + // maybe phpseclib should force close the connection after x request / responses? unless something like that is done + // there could be an infinite loop of request / responses. + return $this->keyboard_interactive_process(); + case NET_SSH2_MSG_USERAUTH_SUCCESS: + return true; + case NET_SSH2_MSG_USERAUTH_FAILURE: + list($auth_methods) = Strings::unpackSSH2('L', $response); + $this->auth_methods_to_continue = $auth_methods; + return false; + } + + return false; + } + + /** + * Login with an ssh-agent provided key + * + * @param string $username + * @param \phpseclib3\System\SSH\Agent $agent + * @return bool + */ + private function ssh_agent_login($username, Agent $agent) + { + $this->agent = $agent; + $keys = $agent->requestIdentities(); + foreach ($keys as $key) { + if ($this->privatekey_login($username, $key)) { + return true; + } + } + + return false; + } + + /** + * Login with an RSA private key + * + * {@internal It might be worthwhile, at some point, to protect against {@link http://tools.ietf.org/html/rfc4251#section-9.3.9 traffic analysis} + * by sending dummy SSH_MSG_IGNORE messages.} + * + * @param string $username + * @param \phpseclib3\Crypt\Common\PrivateKey $privatekey + * @return bool + * @throws \RuntimeException on connection error + */ + private function privatekey_login($username, PrivateKey $privatekey) + { + $publickey = $privatekey->getPublicKey(); + + if ($publickey instanceof RSA) { + $privatekey = $privatekey->withPadding(RSA::SIGNATURE_PKCS1); + $algos = ['rsa-sha2-256', 'rsa-sha2-512', 'ssh-rsa']; + if (isset($this->preferred['hostkey'])) { + $algos = array_intersect($algos, $this->preferred['hostkey']); + } + $algo = self::array_intersect_first($algos, $this->supported_private_key_algorithms); + switch ($algo) { + case 'rsa-sha2-512': + $hash = 'sha512'; + $signatureType = 'rsa-sha2-512'; + break; + case 'rsa-sha2-256': + $hash = 'sha256'; + $signatureType = 'rsa-sha2-256'; + break; + //case 'ssh-rsa': + default: + $hash = 'sha1'; + $signatureType = 'ssh-rsa'; + } + } elseif ($publickey instanceof EC) { + $privatekey = $privatekey->withSignatureFormat('SSH2'); + $curveName = $privatekey->getCurve(); + switch ($curveName) { + case 'Ed25519': + $hash = 'sha512'; + $signatureType = 'ssh-ed25519'; + break; + case 'secp256r1': // nistp256 + $hash = 'sha256'; + $signatureType = 'ecdsa-sha2-nistp256'; + break; + case 'secp384r1': // nistp384 + $hash = 'sha384'; + $signatureType = 'ecdsa-sha2-nistp384'; + break; + case 'secp521r1': // nistp521 + $hash = 'sha512'; + $signatureType = 'ecdsa-sha2-nistp521'; + break; + default: + if (is_array($curveName)) { + throw new UnsupportedCurveException('Specified Curves are not supported by SSH2'); + } + throw new UnsupportedCurveException('Named Curve of ' . $curveName . ' is not supported by phpseclib3\'s SSH2 implementation'); + } + } elseif ($publickey instanceof DSA) { + $privatekey = $privatekey->withSignatureFormat('SSH2'); + $hash = 'sha1'; + $signatureType = 'ssh-dss'; + } else { + throw new UnsupportedAlgorithmException('Please use either an RSA key, an EC one or a DSA key'); + } + + $publickeyStr = $publickey->toString('OpenSSH', ['binary' => true]); + + $part1 = Strings::packSSH2( + 'Csss', + NET_SSH2_MSG_USERAUTH_REQUEST, + $username, + 'ssh-connection', + 'publickey' + ); + $part2 = Strings::packSSH2('ss', $signatureType, $publickeyStr); + + $packet = $part1 . chr(0) . $part2; + $this->send_binary_packet($packet); + + $response = $this->get_binary_packet(); + + list($type) = Strings::unpackSSH2('C', $response); + switch ($type) { + case NET_SSH2_MSG_USERAUTH_FAILURE: + list($auth_methods) = Strings::unpackSSH2('L', $response); + if (in_array('publickey', $auth_methods) && substr($signatureType, 0, 9) == 'rsa-sha2-') { + $this->supported_private_key_algorithms = array_diff($this->supported_private_key_algorithms, ['rsa-sha2-256', 'rsa-sha2-512']); + return $this->privatekey_login($username, $privatekey); + } + $this->auth_methods_to_continue = $auth_methods; + $this->errors[] = 'SSH_MSG_USERAUTH_FAILURE'; + return false; + case NET_SSH2_MSG_USERAUTH_PK_OK: + // we'll just take it on faith that the public key blob and the public key algorithm name are as + // they should be + $this->updateLogHistory('UNKNOWN (60)', 'NET_SSH2_MSG_USERAUTH_PK_OK'); + break; + case NET_SSH2_MSG_USERAUTH_SUCCESS: + $this->bitmap |= self::MASK_LOGIN; + return true; + default: + $this->disconnect_helper(NET_SSH2_DISCONNECT_BY_APPLICATION); + throw new ConnectionClosedException('Unexpected response to publickey authentication pt 1'); + } + + $packet = $part1 . chr(1) . $part2; + $privatekey = $privatekey->withHash($hash); + $signature = $privatekey->sign(Strings::packSSH2('s', $this->session_id) . $packet); + if ($publickey instanceof RSA) { + $signature = Strings::packSSH2('ss', $signatureType, $signature); + } + $packet .= Strings::packSSH2('s', $signature); + + $this->send_binary_packet($packet); + + $response = $this->get_binary_packet(); + + list($type) = Strings::unpackSSH2('C', $response); + switch ($type) { + case NET_SSH2_MSG_USERAUTH_FAILURE: + // either the login is bad or the server employs multi-factor authentication + list($auth_methods) = Strings::unpackSSH2('L', $response); + $this->auth_methods_to_continue = $auth_methods; + return false; + case NET_SSH2_MSG_USERAUTH_SUCCESS: + $this->bitmap |= self::MASK_LOGIN; + return true; + } + + $this->disconnect_helper(NET_SSH2_DISCONNECT_BY_APPLICATION); + throw new ConnectionClosedException('Unexpected response to publickey authentication pt 2'); + } + + /** + * Return the currently configured timeout + * + * @return int + */ + public function getTimeout() + { + return $this->timeout; + } + + /** + * Set Timeout + * + * $ssh->exec('ping 127.0.0.1'); on a Linux host will never return and will run indefinitely. setTimeout() makes it so it'll timeout. + * Setting $timeout to false or 0 will mean there is no timeout. + * + * @param mixed $timeout + */ + public function setTimeout($timeout) + { + $this->timeout = $this->curTimeout = $timeout; + } + + /** + * Set Keep Alive + * + * Sends an SSH2_MSG_IGNORE message every x seconds, if x is a positive non-zero number. + * + * @param int $interval + */ + public function setKeepAlive($interval) + { + $this->keepAlive = $interval; + } + + /** + * Get the output from stdError + * + */ + public function getStdError() + { + return $this->stdErrorLog; + } + + /** + * Execute Command + * + * If $callback is set to false then \phpseclib3\Net\SSH2::get_channel_packet(self::CHANNEL_EXEC) will need to be called manually. + * In all likelihood, this is not a feature you want to be taking advantage of. + * + * @param string $command + * @return string|bool + * @psalm-return ($callback is callable ? bool : string|bool) + * @throws \RuntimeException on connection error + */ + public function exec($command, callable $callback = null) + { + $this->curTimeout = $this->timeout; + $this->is_timeout = false; + $this->stdErrorLog = ''; + + if (!$this->isAuthenticated()) { + return false; + } + + //if ($this->isPTYOpen()) { + // throw new \RuntimeException('If you want to run multiple exec()\'s you will need to disable (and re-enable if appropriate) a PTY for each one.'); + //} + + $this->openChannel(self::CHANNEL_EXEC); + + if ($this->request_pty === true) { + $terminal_modes = pack('C', NET_SSH2_TTY_OP_END); + $packet = Strings::packSSH2( + 'CNsCsN4s', + NET_SSH2_MSG_CHANNEL_REQUEST, + $this->server_channels[self::CHANNEL_EXEC], + 'pty-req', + 1, + $this->term, + $this->windowColumns, + $this->windowRows, + 0, + 0, + $terminal_modes + ); + + $this->send_binary_packet($packet); + + $this->channel_status[self::CHANNEL_EXEC] = NET_SSH2_MSG_CHANNEL_REQUEST; + if (!$this->get_channel_packet(self::CHANNEL_EXEC)) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_BY_APPLICATION); + throw new \RuntimeException('Unable to request pseudo-terminal'); + } + } + + // sending a pty-req SSH_MSG_CHANNEL_REQUEST message is unnecessary and, in fact, in most cases, slows things + // down. the one place where it might be desirable is if you're doing something like \phpseclib3\Net\SSH2::exec('ping localhost &'). + // with a pty-req SSH_MSG_CHANNEL_REQUEST, exec() will return immediately and the ping process will then + // then immediately terminate. without such a request exec() will loop indefinitely. the ping process won't end but + // neither will your script. + + // although, in theory, the size of SSH_MSG_CHANNEL_REQUEST could exceed the maximum packet size established by + // SSH_MSG_CHANNEL_OPEN_CONFIRMATION, RFC4254#section-5.1 states that the "maximum packet size" refers to the + // "maximum size of an individual data packet". ie. SSH_MSG_CHANNEL_DATA. RFC4254#section-5.2 corroborates. + $packet = Strings::packSSH2( + 'CNsCs', + NET_SSH2_MSG_CHANNEL_REQUEST, + $this->server_channels[self::CHANNEL_EXEC], + 'exec', + 1, + $command + ); + $this->send_binary_packet($packet); + + $this->channel_status[self::CHANNEL_EXEC] = NET_SSH2_MSG_CHANNEL_REQUEST; + + if (!$this->get_channel_packet(self::CHANNEL_EXEC)) { + return false; + } + + $this->channel_status[self::CHANNEL_EXEC] = NET_SSH2_MSG_CHANNEL_DATA; + + if ($this->request_pty === true) { + $this->channel_id_last_interactive = self::CHANNEL_EXEC; + return true; + } + + $output = ''; + while (true) { + $temp = $this->get_channel_packet(self::CHANNEL_EXEC); + switch (true) { + case $temp === true: + return is_callable($callback) ? true : $output; + case $temp === false: + return false; + default: + if (is_callable($callback)) { + if ($callback($temp) === true) { + $this->close_channel(self::CHANNEL_EXEC); + return true; + } + } else { + $output .= $temp; + } + } + } + } + + /** + * How many channels are currently open? + * + * @return int + */ + public function getOpenChannelCount() + { + return $this->channelCount; + } + + /** + * Opens a channel + * + * @param string $channel + * @param bool $skip_extended + * @return bool + */ + protected function openChannel($channel, $skip_extended = false) + { + if (isset($this->channel_status[$channel]) && $this->channel_status[$channel] != NET_SSH2_MSG_CHANNEL_CLOSE) { + throw new \RuntimeException('Please close the channel (' . $channel . ') before trying to open it again'); + } + + $this->channelCount++; + + if ($this->channelCount > 1 && $this->errorOnMultipleChannels) { + throw new \RuntimeException("Ubuntu's OpenSSH from 5.8 to 6.9 doesn't work with multiple channels"); + } + + // RFC4254 defines the (client) window size as "bytes the other party can send before it must wait for the window to + // be adjusted". 0x7FFFFFFF is, at 2GB, the max size. technically, it should probably be decremented, but, + // honestly, if you're transferring more than 2GB, you probably shouldn't be using phpseclib, anyway. + // see http://tools.ietf.org/html/rfc4254#section-5.2 for more info + $this->window_size_server_to_client[$channel] = $this->window_size; + // 0x8000 is the maximum max packet size, per http://tools.ietf.org/html/rfc4253#section-6.1, although since PuTTy + // uses 0x4000, that's what will be used here, as well. + $packet_size = 0x4000; + + $packet = Strings::packSSH2( + 'CsN3', + NET_SSH2_MSG_CHANNEL_OPEN, + 'session', + $channel, + $this->window_size_server_to_client[$channel], + $packet_size + ); + + $this->send_binary_packet($packet); + + $this->channel_status[$channel] = NET_SSH2_MSG_CHANNEL_OPEN; + + return $this->get_channel_packet($channel, $skip_extended); + } + + /** + * Creates an interactive shell + * + * Returns bool(true) if the shell was opened. + * Returns bool(false) if the shell was already open. + * + * @see self::isShellOpen() + * @see self::read() + * @see self::write() + * @return bool + * @throws InsufficientSetupException if not authenticated + * @throws \UnexpectedValueException on receipt of unexpected packets + * @throws \RuntimeException on other errors + */ + public function openShell() + { + if (!$this->isAuthenticated()) { + throw new InsufficientSetupException('Operation disallowed prior to login()'); + } + + $this->openChannel(self::CHANNEL_SHELL); + + $terminal_modes = pack('C', NET_SSH2_TTY_OP_END); + $packet = Strings::packSSH2( + 'CNsbsN4s', + NET_SSH2_MSG_CHANNEL_REQUEST, + $this->server_channels[self::CHANNEL_SHELL], + 'pty-req', + true, // want reply + $this->term, + $this->windowColumns, + $this->windowRows, + 0, + 0, + $terminal_modes + ); + + $this->send_binary_packet($packet); + + $this->channel_status[self::CHANNEL_SHELL] = NET_SSH2_MSG_CHANNEL_REQUEST; + + if (!$this->get_channel_packet(self::CHANNEL_SHELL)) { + throw new \RuntimeException('Unable to request pty'); + } + + $packet = Strings::packSSH2( + 'CNsb', + NET_SSH2_MSG_CHANNEL_REQUEST, + $this->server_channels[self::CHANNEL_SHELL], + 'shell', + true // want reply + ); + $this->send_binary_packet($packet); + + $response = $this->get_channel_packet(self::CHANNEL_SHELL); + if ($response === false) { + throw new \RuntimeException('Unable to request shell'); + } + + $this->channel_status[self::CHANNEL_SHELL] = NET_SSH2_MSG_CHANNEL_DATA; + + $this->channel_id_last_interactive = self::CHANNEL_SHELL; + + $this->bitmap |= self::MASK_SHELL; + + return true; + } + + /** + * Return the channel to be used with read(), write(), and reset(), if none were specified + * @deprecated for lack of transparency in intended channel target, to be potentially replaced + * with method which guarantees open-ness of all yielded channels and throws + * error for multiple open channels + * @see self::read() + * @see self::write() + * @return int + */ + private function get_interactive_channel() + { + switch (true) { + case $this->is_channel_status_data(self::CHANNEL_SUBSYSTEM): + return self::CHANNEL_SUBSYSTEM; + case $this->is_channel_status_data(self::CHANNEL_EXEC): + return self::CHANNEL_EXEC; + default: + return self::CHANNEL_SHELL; + } + } + + /** + * Indicates the DATA status on the given channel + * + * @param int $channel The channel number to evaluate + * @return bool + */ + private function is_channel_status_data($channel) + { + return isset($this->channel_status[$channel]) && $this->channel_status[$channel] == NET_SSH2_MSG_CHANNEL_DATA; + } + + /** + * Return an available open channel + * + * @return int + */ + private function get_open_channel() + { + $channel = self::CHANNEL_EXEC; + do { + if (isset($this->channel_status[$channel]) && $this->channel_status[$channel] == NET_SSH2_MSG_CHANNEL_OPEN) { + return $channel; + } + } while ($channel++ < self::CHANNEL_SUBSYSTEM); + + return false; + } + + /** + * Request agent forwarding of remote server + * + * @return bool + */ + public function requestAgentForwarding() + { + $request_channel = $this->get_open_channel(); + if ($request_channel === false) { + return false; + } + + $packet = Strings::packSSH2( + 'CNsC', + NET_SSH2_MSG_CHANNEL_REQUEST, + $this->server_channels[$request_channel], + '[email protected]', + 1 + ); + + $this->channel_status[$request_channel] = NET_SSH2_MSG_CHANNEL_REQUEST; + + $this->send_binary_packet($packet); + + if (!$this->get_channel_packet($request_channel)) { + return false; + } + + $this->channel_status[$request_channel] = NET_SSH2_MSG_CHANNEL_OPEN; + + return true; + } + + /** + * Returns the output of an interactive shell + * + * Returns when there's a match for $expect, which can take the form of a string literal or, + * if $mode == self::READ_REGEX, a regular expression. + * + * If not specifying a channel, an open interactive channel will be selected, or, if there are + * no open channels, an interactive shell will be created. If there are multiple open + * interactive channels, a legacy behavior will apply in which channel selection prioritizes + * an active subsystem, the exec pty, and, lastly, the shell. If using multiple interactive + * channels, callers are discouraged from relying on this legacy behavior and should specify + * the intended channel. + * + * @see self::write() + * @param string $expect + * @param int $mode One of the self::READ_* constants + * @param int|null $channel Channel id returned by self::getInteractiveChannelId() + * @return string|bool|null + * @throws \RuntimeException on connection error + * @throws InsufficientSetupException on unexpected channel status, possibly due to closure + */ + public function read($expect = '', $mode = self::READ_SIMPLE, $channel = null) + { + if (!$this->isAuthenticated()) { + throw new InsufficientSetupException('Operation disallowed prior to login()'); + } + + $this->curTimeout = $this->timeout; + $this->is_timeout = false; + + if ($channel === null) { + $channel = $this->get_interactive_channel(); + } + + if (!$this->is_channel_status_data($channel) && empty($this->channel_buffers[$channel])) { + if ($channel != self::CHANNEL_SHELL) { + throw new InsufficientSetupException('Data is not available on channel'); + } elseif (!$this->openShell()) { + throw new \RuntimeException('Unable to initiate an interactive shell session'); + } + } + + if ($mode == self::READ_NEXT) { + return $this->get_channel_packet($channel); + } + + $match = $expect; + while (true) { + if ($mode == self::READ_REGEX) { + preg_match($expect, substr($this->interactiveBuffer, -1024), $matches); + $match = isset($matches[0]) ? $matches[0] : ''; + } + $pos = strlen($match) ? strpos($this->interactiveBuffer, $match) : false; + if ($pos !== false) { + return Strings::shift($this->interactiveBuffer, $pos + strlen($match)); + } + $response = $this->get_channel_packet($channel); + if ($response === true) { + return Strings::shift($this->interactiveBuffer, strlen($this->interactiveBuffer)); + } + + $this->interactiveBuffer .= $response; + } + } + + /** + * Inputs a command into an interactive shell. + * + * If not specifying a channel, an open interactive channel will be selected, or, if there are + * no open channels, an interactive shell will be created. If there are multiple open + * interactive channels, a legacy behavior will apply in which channel selection prioritizes + * an active subsystem, the exec pty, and, lastly, the shell. If using multiple interactive + * channels, callers are discouraged from relying on this legacy behavior and should specify + * the intended channel. + * + * @see SSH2::read() + * @param string $cmd + * @param int|null $channel Channel id returned by self::getInteractiveChannelId() + * @return void + * @throws \RuntimeException on connection error + * @throws InsufficientSetupException on unexpected channel status, possibly due to closure + */ + public function write($cmd, $channel = null) + { + if (!$this->isAuthenticated()) { + throw new InsufficientSetupException('Operation disallowed prior to login()'); + } + + if ($channel === null) { + $channel = $this->get_interactive_channel(); + } + + if (!$this->is_channel_status_data($channel)) { + if ($channel != self::CHANNEL_SHELL) { + throw new InsufficientSetupException('Data is not available on channel'); + } elseif (!$this->openShell()) { + throw new \RuntimeException('Unable to initiate an interactive shell session'); + } + } + + $this->send_channel_packet($channel, $cmd); + } + + /** + * Start a subsystem. + * + * Right now only one subsystem at a time is supported. To support multiple subsystem's stopSubsystem() could accept + * a string that contained the name of the subsystem, but at that point, only one subsystem of each type could be opened. + * To support multiple subsystem's of the same name maybe it'd be best if startSubsystem() generated a new channel id and + * returns that and then that that was passed into stopSubsystem() but that'll be saved for a future date and implemented + * if there's sufficient demand for such a feature. + * + * @see self::stopSubsystem() + * @param string $subsystem + * @return bool + */ + public function startSubsystem($subsystem) + { + $this->openChannel(self::CHANNEL_SUBSYSTEM); + + $packet = Strings::packSSH2( + 'CNsCs', + NET_SSH2_MSG_CHANNEL_REQUEST, + $this->server_channels[self::CHANNEL_SUBSYSTEM], + 'subsystem', + 1, + $subsystem + ); + $this->send_binary_packet($packet); + + $this->channel_status[self::CHANNEL_SUBSYSTEM] = NET_SSH2_MSG_CHANNEL_REQUEST; + + if (!$this->get_channel_packet(self::CHANNEL_SUBSYSTEM)) { + return false; + } + + $this->channel_status[self::CHANNEL_SUBSYSTEM] = NET_SSH2_MSG_CHANNEL_DATA; + + $this->channel_id_last_interactive = self::CHANNEL_SUBSYSTEM; + + return true; + } + + /** + * Stops a subsystem. + * + * @see self::startSubsystem() + * @return bool + */ + public function stopSubsystem() + { + if ($this->isInteractiveChannelOpen(self::CHANNEL_SUBSYSTEM)) { + $this->close_channel(self::CHANNEL_SUBSYSTEM); + } + return true; + } + + /** + * Closes a channel + * + * If read() timed out you might want to just close the channel and have it auto-restart on the next read() call + * + * If not specifying a channel, an open interactive channel will be selected. If there are + * multiple open interactive channels, a legacy behavior will apply in which channel selection + * prioritizes an active subsystem, the exec pty, and, lastly, the shell. If using multiple + * interactive channels, callers are discouraged from relying on this legacy behavior and + * should specify the intended channel. + * + * @param int|null $channel Channel id returned by self::getInteractiveChannelId() + * @return void + */ + public function reset($channel = null) + { + if ($channel === null) { + $channel = $this->get_interactive_channel(); + } + if ($this->isInteractiveChannelOpen($channel)) { + $this->close_channel($channel); + } + } + + /** + * Is timeout? + * + * Did exec() or read() return because they timed out or because they encountered the end? + * + */ + public function isTimeout() + { + return $this->is_timeout; + } + + /** + * Disconnect + * + */ + public function disconnect() + { + $this->disconnect_helper(NET_SSH2_DISCONNECT_BY_APPLICATION); + if (isset($this->realtime_log_file) && is_resource($this->realtime_log_file)) { + fclose($this->realtime_log_file); + } + unset(self::$connections[$this->getResourceId()]); + } + + /** + * Destructor. + * + * Will be called, automatically, if you're supporting just PHP5. If you're supporting PHP4, you'll need to call + * disconnect(). + * + */ + public function __destruct() + { + $this->disconnect(); + } + + /** + * Is the connection still active? + * + * @return bool + */ + public function isConnected() + { + return ($this->bitmap & self::MASK_CONNECTED) && is_resource($this->fsock) && !feof($this->fsock); + } + + /** + * Have you successfully been logged in? + * + * @return bool + */ + public function isAuthenticated() + { + return (bool) ($this->bitmap & self::MASK_LOGIN); + } + + /** + * Is the interactive shell active? + * + * @return bool + */ + public function isShellOpen() + { + return $this->isInteractiveChannelOpen(self::CHANNEL_SHELL); + } + + /** + * Is the exec pty active? + * + * @return bool + */ + public function isPTYOpen() + { + return $this->isInteractiveChannelOpen(self::CHANNEL_EXEC); + } + + /** + * Is the given interactive channel active? + * + * @param int $channel Channel id returned by self::getInteractiveChannelId() + * @return bool + */ + public function isInteractiveChannelOpen($channel) + { + return $this->isAuthenticated() && $this->is_channel_status_data($channel); + } + + /** + * Returns a channel identifier, presently of the last interactive channel opened, regardless of current status. + * Returns 0 if no interactive channel has been opened. + * + * @see self::isInteractiveChannelOpen() + * @return int + */ + public function getInteractiveChannelId() + { + return $this->channel_id_last_interactive; + } + + /** + * Pings a server connection, or tries to reconnect if the connection has gone down + * + * Inspired by http://php.net/manual/en/mysqli.ping.php + * + * @return bool + */ + public function ping() + { + if (!$this->isAuthenticated()) { + if (!empty($this->auth)) { + return $this->reconnect(); + } + return false; + } + + try { + $this->openChannel(self::CHANNEL_KEEP_ALIVE); + } catch (\RuntimeException $e) { + return $this->reconnect(); + } + + $this->close_channel(self::CHANNEL_KEEP_ALIVE); + return true; + } + + /** + * In situ reconnect method + * + * @return boolean + */ + private function reconnect() + { + $this->reset_connection(NET_SSH2_DISCONNECT_CONNECTION_LOST); + $this->retry_connect = true; + $this->connect(); + foreach ($this->auth as $auth) { + $result = $this->login(...$auth); + } + return $result; + } + + /** + * Resets a connection for re-use + * + * @param int $reason + */ + protected function reset_connection($reason) + { + $this->disconnect_helper($reason); + $this->decrypt = $this->encrypt = false; + $this->decrypt_block_size = $this->encrypt_block_size = 8; + $this->hmac_check = $this->hmac_create = false; + $this->hmac_size = false; + $this->session_id = false; + $this->retry_connect = true; + $this->get_seq_no = $this->send_seq_no = 0; + $this->channel_status = []; + $this->channel_id_last_interactive = 0; + } + + /** + * Gets Binary Packets + * + * See '6. Binary Packet Protocol' of rfc4253 for more info. + * + * @see self::_send_binary_packet() + * @param bool $skip_channel_filter + * @return bool|string + */ + private function get_binary_packet($skip_channel_filter = false) + { + if ($skip_channel_filter) { + if (!is_resource($this->fsock)) { + throw new \InvalidArgumentException('fsock is not a resource.'); + } + $read = [$this->fsock]; + $write = $except = null; + + if (!$this->curTimeout) { + if ($this->keepAlive <= 0) { + static::stream_select($read, $write, $except, null); + } else { + if (!static::stream_select($read, $write, $except, $this->keepAlive)) { + $this->send_binary_packet(pack('CN', NET_SSH2_MSG_IGNORE, 0)); + return $this->get_binary_packet(true); + } + } + } else { + if ($this->curTimeout < 0) { + $this->is_timeout = true; + return true; + } + + $start = microtime(true); + + if ($this->keepAlive > 0 && $this->keepAlive < $this->curTimeout) { + if (!static::stream_select($read, $write, $except, $this->keepAlive)) { + $this->send_binary_packet(pack('CN', NET_SSH2_MSG_IGNORE, 0)); + $elapsed = microtime(true) - $start; + $this->curTimeout -= $elapsed; + return $this->get_binary_packet(true); + } + $elapsed = microtime(true) - $start; + $this->curTimeout -= $elapsed; + } + + $sec = (int) floor($this->curTimeout); + $usec = (int) (1000000 * ($this->curTimeout - $sec)); + + // this can return a "stream_select(): unable to select [4]: Interrupted system call" error + if (!static::stream_select($read, $write, $except, $sec, $usec)) { + $this->is_timeout = true; + return true; + } + $elapsed = microtime(true) - $start; + $this->curTimeout -= $elapsed; + } + } + + if (!is_resource($this->fsock) || feof($this->fsock)) { + $this->bitmap = 0; + $str = 'Connection closed (by server) prematurely'; + if (isset($elapsed)) { + $str .= ' ' . $elapsed . 's'; + } + throw new ConnectionClosedException($str); + } + + $start = microtime(true); + $raw = stream_get_contents($this->fsock, $this->decrypt_block_size); + + if (!strlen($raw)) { + $this->bitmap = 0; + throw new ConnectionClosedException('No data received from server'); + } + + if ($this->decrypt) { + switch ($this->decryptName) { + case '[email protected]': + case '[email protected]': + $this->decrypt->setNonce( + $this->decryptFixedPart . + $this->decryptInvocationCounter + ); + Strings::increment_str($this->decryptInvocationCounter); + $this->decrypt->setAAD($temp = Strings::shift($raw, 4)); + extract(unpack('Npacket_length', $temp)); + /** + * @var integer $packet_length + */ + + $raw .= $this->read_remaining_bytes($packet_length - $this->decrypt_block_size + 4); + $stop = microtime(true); + $tag = stream_get_contents($this->fsock, $this->decrypt_block_size); + $this->decrypt->setTag($tag); + $raw = $this->decrypt->decrypt($raw); + $raw = $temp . $raw; + $remaining_length = 0; + break; + case '[email protected]': + // This should be impossible, but we are checking anyway to narrow the type for Psalm. + if (!($this->decrypt instanceof ChaCha20)) { + throw new \LogicException('$this->decrypt is not a ' . ChaCha20::class); + } + + $nonce = pack('N2', 0, $this->get_seq_no); + + $this->lengthDecrypt->setNonce($nonce); + $temp = $this->lengthDecrypt->decrypt($aad = Strings::shift($raw, 4)); + extract(unpack('Npacket_length', $temp)); + /** + * @var integer $packet_length + */ + + $raw .= $this->read_remaining_bytes($packet_length - $this->decrypt_block_size + 4); + $stop = microtime(true); + $tag = stream_get_contents($this->fsock, 16); + + $this->decrypt->setNonce($nonce); + $this->decrypt->setCounter(0); + // this is the same approach that's implemented in Salsa20::createPoly1305Key() + // but we don't want to use the same AEAD construction that RFC8439 describes + // for ChaCha20-Poly1305 so we won't rely on it (see Salsa20::poly1305()) + $this->decrypt->setPoly1305Key( + $this->decrypt->encrypt(str_repeat("\0", 32)) + ); + $this->decrypt->setAAD($aad); + $this->decrypt->setCounter(1); + $this->decrypt->setTag($tag); + $raw = $this->decrypt->decrypt($raw); + $raw = $temp . $raw; + $remaining_length = 0; + break; + default: + if (!$this->hmac_check instanceof Hash || !$this->hmac_check_etm) { + $raw = $this->decrypt->decrypt($raw); + break; + } + extract(unpack('Npacket_length', $temp = Strings::shift($raw, 4))); + /** + * @var integer $packet_length + */ + $raw .= $this->read_remaining_bytes($packet_length - $this->decrypt_block_size + 4); + $stop = microtime(true); + $encrypted = $temp . $raw; + $raw = $temp . $this->decrypt->decrypt($raw); + $remaining_length = 0; + } + } + + if (strlen($raw) < 5) { + $this->bitmap = 0; + throw new \RuntimeException('Plaintext is too short'); + } + extract(unpack('Npacket_length/Cpadding_length', Strings::shift($raw, 5))); + /** + * @var integer $packet_length + * @var integer $padding_length + */ + + if (!isset($remaining_length)) { + $remaining_length = $packet_length + 4 - $this->decrypt_block_size; + } + + $buffer = $this->read_remaining_bytes($remaining_length); + + if (!isset($stop)) { + $stop = microtime(true); + } + if (strlen($buffer)) { + $raw .= $this->decrypt ? $this->decrypt->decrypt($buffer) : $buffer; + } + + $payload = Strings::shift($raw, $packet_length - $padding_length - 1); + $padding = Strings::shift($raw, $padding_length); // should leave $raw empty + + if ($this->hmac_check instanceof Hash) { + $hmac = stream_get_contents($this->fsock, $this->hmac_size); + if ($hmac === false || strlen($hmac) != $this->hmac_size) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_MAC_ERROR); + throw new \RuntimeException('Error reading socket'); + } + + $reconstructed = !$this->hmac_check_etm ? + pack('NCa*', $packet_length, $padding_length, $payload . $padding) : + $encrypted; + if (($this->hmac_check->getHash() & "\xFF\xFF\xFF\xFF") == 'umac') { + $this->hmac_check->setNonce("\0\0\0\0" . pack('N', $this->get_seq_no)); + if ($hmac != $this->hmac_check->hash($reconstructed)) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_MAC_ERROR); + throw new \RuntimeException('Invalid UMAC'); + } + } else { + if ($hmac != $this->hmac_check->hash(pack('Na*', $this->get_seq_no, $reconstructed))) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_MAC_ERROR); + throw new \RuntimeException('Invalid HMAC'); + } + } + } + + switch ($this->decompress) { + case self::NET_SSH2_COMPRESSION_ZLIB_AT_OPENSSH: + if (!$this->isAuthenticated()) { + break; + } + // fall-through + case self::NET_SSH2_COMPRESSION_ZLIB: + if ($this->regenerate_decompression_context) { + $this->regenerate_decompression_context = false; + + $cmf = ord($payload[0]); + $cm = $cmf & 0x0F; + if ($cm != 8) { // deflate + user_error("Only CM = 8 ('deflate') is supported ($cm)"); + } + $cinfo = ($cmf & 0xF0) >> 4; + if ($cinfo > 7) { + user_error("CINFO above 7 is not allowed ($cinfo)"); + } + $windowSize = 1 << ($cinfo + 8); + + $flg = ord($payload[1]); + //$fcheck = $flg && 0x0F; + if ((($cmf << 8) | $flg) % 31) { + user_error('fcheck failed'); + } + $fdict = boolval($flg & 0x20); + $flevel = ($flg & 0xC0) >> 6; + + $this->decompress_context = inflate_init(ZLIB_ENCODING_RAW, ['window' => $cinfo + 8]); + $payload = substr($payload, 2); + } + if ($this->decompress_context) { + $payload = inflate_add($this->decompress_context, $payload, ZLIB_PARTIAL_FLUSH); + } + } + + $this->get_seq_no++; + + if (defined('NET_SSH2_LOGGING')) { + $current = microtime(true); + $message_number = isset(self::$message_numbers[ord($payload[0])]) ? self::$message_numbers[ord($payload[0])] : 'UNKNOWN (' . ord($payload[0]) . ')'; + $message_number = '<- ' . $message_number . + ' (since last: ' . round($current - $this->last_packet, 4) . ', network: ' . round($stop - $start, 4) . 's)'; + $this->append_log($message_number, $payload); + $this->last_packet = $current; + } + + return $this->filter($payload, $skip_channel_filter); + } + + /** + * Read Remaining Bytes + * + * @see self::get_binary_packet() + * @param int $remaining_length + * @return string + */ + private function read_remaining_bytes($remaining_length) + { + if (!$remaining_length) { + return ''; + } + + $adjustLength = false; + if ($this->decrypt) { + switch (true) { + case $this->decryptName == '[email protected]': + case $this->decryptName == '[email protected]': + case $this->decryptName == '[email protected]': + case $this->hmac_check instanceof Hash && $this->hmac_check_etm: + $remaining_length += $this->decrypt_block_size - 4; + $adjustLength = true; + } + } + + // quoting <http://tools.ietf.org/html/rfc4253#section-6.1>, + // "implementations SHOULD check that the packet length is reasonable" + // PuTTY uses 0x9000 as the actual max packet size and so to shall we + // don't do this when GCM mode is used since GCM mode doesn't encrypt the length + if ($remaining_length < -$this->decrypt_block_size || $remaining_length > 0x9000 || $remaining_length % $this->decrypt_block_size != 0) { + if (!$this->bad_key_size_fix && self::bad_algorithm_candidate($this->decrypt ? $this->decryptName : '') && !($this->bitmap & SSH2::MASK_LOGIN)) { + $this->bad_key_size_fix = true; + $this->reset_connection(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED); + return false; + } + throw new \RuntimeException('Invalid size'); + } + + if ($adjustLength) { + $remaining_length -= $this->decrypt_block_size - 4; + } + + $buffer = ''; + while ($remaining_length > 0) { + $temp = stream_get_contents($this->fsock, $remaining_length); + if ($temp === false || feof($this->fsock)) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_CONNECTION_LOST); + throw new \RuntimeException('Error reading from socket'); + } + $buffer .= $temp; + $remaining_length -= strlen($temp); + } + + return $buffer; + } + + /** + * Filter Binary Packets + * + * Because some binary packets need to be ignored... + * + * @see self::_get_binary_packet() + * @param string $payload + * @param bool $skip_channel_filter + * @return string|bool + */ + private function filter($payload, $skip_channel_filter) + { + switch (ord($payload[0])) { + case NET_SSH2_MSG_DISCONNECT: + Strings::shift($payload, 1); + list($reason_code, $message) = Strings::unpackSSH2('Ns', $payload); + $this->errors[] = 'SSH_MSG_DISCONNECT: ' . self::$disconnect_reasons[$reason_code] . "\r\n$message"; + $this->bitmap = 0; + return false; + case NET_SSH2_MSG_IGNORE: + $this->extra_packets++; + $payload = $this->get_binary_packet($skip_channel_filter); + break; + case NET_SSH2_MSG_DEBUG: + $this->extra_packets++; + Strings::shift($payload, 2); // second byte is "always_display" + list($message) = Strings::unpackSSH2('s', $payload); + $this->errors[] = "SSH_MSG_DEBUG: $message"; + $payload = $this->get_binary_packet($skip_channel_filter); + break; + case NET_SSH2_MSG_UNIMPLEMENTED: + return false; + case NET_SSH2_MSG_KEXINIT: + // this is here for key re-exchanges after the initial key exchange + if ($this->session_id !== false) { + if (!$this->key_exchange($payload)) { + $this->bitmap = 0; + return false; + } + $payload = $this->get_binary_packet($skip_channel_filter); + } + } + + // see http://tools.ietf.org/html/rfc4252#section-5.4; only called when the encryption has been activated and when we haven't already logged in + if (($this->bitmap & self::MASK_CONNECTED) && !$this->isAuthenticated() && !is_bool($payload) && ord($payload[0]) == NET_SSH2_MSG_USERAUTH_BANNER) { + Strings::shift($payload, 1); + list($this->banner_message) = Strings::unpackSSH2('s', $payload); + $payload = $this->get_binary_packet(); + } + + // only called when we've already logged in + if (($this->bitmap & self::MASK_CONNECTED) && $this->isAuthenticated()) { + if (is_bool($payload)) { + return $payload; + } + + switch (ord($payload[0])) { + case NET_SSH2_MSG_CHANNEL_REQUEST: + if (strlen($payload) == 31) { + extract(unpack('cpacket_type/Nchannel/Nlength', $payload)); + if (substr($payload, 9, $length) == '[email protected]' && isset($this->server_channels[$channel])) { + if (ord(substr($payload, 9 + $length))) { // want reply + $this->send_binary_packet(pack('CN', NET_SSH2_MSG_CHANNEL_SUCCESS, $this->server_channels[$channel])); + } + $payload = $this->get_binary_packet($skip_channel_filter); + } + } + break; + case NET_SSH2_MSG_CHANNEL_DATA: + case NET_SSH2_MSG_CHANNEL_EXTENDED_DATA: + case NET_SSH2_MSG_CHANNEL_CLOSE: + case NET_SSH2_MSG_CHANNEL_EOF: + if (!$skip_channel_filter && !empty($this->server_channels)) { + $this->binary_packet_buffer = $payload; + $this->get_channel_packet(true); + $payload = $this->get_binary_packet(); + } + break; + case NET_SSH2_MSG_GLOBAL_REQUEST: // see http://tools.ietf.org/html/rfc4254#section-4 + Strings::shift($payload, 1); + list($request_name) = Strings::unpackSSH2('s', $payload); + $this->errors[] = "SSH_MSG_GLOBAL_REQUEST: $request_name"; + + try { + $this->send_binary_packet(pack('C', NET_SSH2_MSG_REQUEST_FAILURE)); + } catch (\RuntimeException $e) { + return $this->disconnect_helper(NET_SSH2_DISCONNECT_BY_APPLICATION); + } + + $payload = $this->get_binary_packet($skip_channel_filter); + break; + case NET_SSH2_MSG_CHANNEL_OPEN: // see http://tools.ietf.org/html/rfc4254#section-5.1 + Strings::shift($payload, 1); + list($data, $server_channel) = Strings::unpackSSH2('sN', $payload); + switch ($data) { + case 'auth-agent': + case '[email protected]': + if (isset($this->agent)) { + $new_channel = self::CHANNEL_AGENT_FORWARD; + + list( + $remote_window_size, + $remote_maximum_packet_size + ) = Strings::unpackSSH2('NN', $payload); + + $this->packet_size_client_to_server[$new_channel] = $remote_window_size; + $this->window_size_server_to_client[$new_channel] = $remote_maximum_packet_size; + $this->window_size_client_to_server[$new_channel] = $this->window_size; + + $packet_size = 0x4000; + + $packet = pack( + 'CN4', + NET_SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, + $server_channel, + $new_channel, + $packet_size, + $packet_size + ); + + $this->server_channels[$new_channel] = $server_channel; + $this->channel_status[$new_channel] = NET_SSH2_MSG_CHANNEL_OPEN_CONFIRMATION; + $this->send_binary_packet($packet); + } + break; + default: + $packet = Strings::packSSH2( + 'CN2ss', + NET_SSH2_MSG_CHANNEL_OPEN_FAILURE, + $server_channel, + NET_SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED, + '', // description + '' // language tag + ); + + try { + $this->send_binary_packet($packet); + } catch (\RuntimeException $e) { + return $this->disconnect_helper(NET_SSH2_DISCONNECT_BY_APPLICATION); + } + } + + $payload = $this->get_binary_packet($skip_channel_filter); + break; + case NET_SSH2_MSG_CHANNEL_WINDOW_ADJUST: + Strings::shift($payload, 1); + list($channel, $window_size) = Strings::unpackSSH2('NN', $payload); + + $this->window_size_client_to_server[$channel] += $window_size; + + $payload = ($this->bitmap & self::MASK_WINDOW_ADJUST) ? true : $this->get_binary_packet($skip_channel_filter); + } + } + + return $payload; + } + + /** + * Enable Quiet Mode + * + * Suppress stderr from output + * + */ + public function enableQuietMode() + { + $this->quiet_mode = true; + } + + /** + * Disable Quiet Mode + * + * Show stderr in output + * + */ + public function disableQuietMode() + { + $this->quiet_mode = false; + } + + /** + * Returns whether Quiet Mode is enabled or not + * + * @see self::enableQuietMode() + * @see self::disableQuietMode() + * @return bool + */ + public function isQuietModeEnabled() + { + return $this->quiet_mode; + } + + /** + * Enable request-pty when using exec() + * + */ + public function enablePTY() + { + $this->request_pty = true; + } + + /** + * Disable request-pty when using exec() + * + */ + public function disablePTY() + { + if ($this->isPTYOpen()) { + $this->close_channel(self::CHANNEL_EXEC); + } + $this->request_pty = false; + } + + /** + * Returns whether request-pty is enabled or not + * + * @see self::enablePTY() + * @see self::disablePTY() + * @return bool + */ + public function isPTYEnabled() + { + return $this->request_pty; + } + + /** + * Gets channel data + * + * Returns the data as a string. bool(true) is returned if: + * + * - the server closes the channel + * - if the connection times out + * - if the channel status is CHANNEL_OPEN and the response was CHANNEL_OPEN_CONFIRMATION + * - if the channel status is CHANNEL_REQUEST and the response was CHANNEL_SUCCESS + * - if the channel status is CHANNEL_CLOSE and the response was CHANNEL_CLOSE + * + * bool(false) is returned if: + * + * - if the channel status is CHANNEL_REQUEST and the response was CHANNEL_FAILURE + * + * @param int $client_channel + * @param bool $skip_extended + * @return mixed + * @throws \RuntimeException on connection error + */ + protected function get_channel_packet($client_channel, $skip_extended = false) + { + if (!empty($this->channel_buffers[$client_channel])) { + switch ($this->channel_status[$client_channel]) { + case NET_SSH2_MSG_CHANNEL_REQUEST: + foreach ($this->channel_buffers[$client_channel] as $i => $packet) { + switch (ord($packet[0])) { + case NET_SSH2_MSG_CHANNEL_SUCCESS: + case NET_SSH2_MSG_CHANNEL_FAILURE: + unset($this->channel_buffers[$client_channel][$i]); + return substr($packet, 1); + } + } + break; + default: + return substr(array_shift($this->channel_buffers[$client_channel]), 1); + } + } + + while (true) { + if ($this->binary_packet_buffer !== false) { + $response = $this->binary_packet_buffer; + $this->binary_packet_buffer = false; + } else { + $response = $this->get_binary_packet(true); + if ($response === true && $this->is_timeout) { + if ($client_channel == self::CHANNEL_EXEC && !$this->request_pty) { + $this->close_channel($client_channel); + } + return true; + } + if ($response === false) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_CONNECTION_LOST); + throw new ConnectionClosedException('Connection closed by server'); + } + } + + if ($client_channel == -1 && $response === true) { + return true; + } + list($type, $channel) = Strings::unpackSSH2('CN', $response); + + // will not be setup yet on incoming channel open request + if (isset($channel) && isset($this->channel_status[$channel]) && isset($this->window_size_server_to_client[$channel])) { + $this->window_size_server_to_client[$channel] -= strlen($response); + + // resize the window, if appropriate + if ($this->window_size_server_to_client[$channel] < 0) { + // PuTTY does something more analogous to the following: + //if ($this->window_size_server_to_client[$channel] < 0x3FFFFFFF) { + $packet = pack('CNN', NET_SSH2_MSG_CHANNEL_WINDOW_ADJUST, $this->server_channels[$channel], $this->window_resize); + $this->send_binary_packet($packet); + $this->window_size_server_to_client[$channel] += $this->window_resize; + } + + switch ($type) { + case NET_SSH2_MSG_CHANNEL_EXTENDED_DATA: + /* + if ($client_channel == self::CHANNEL_EXEC) { + $this->send_channel_packet($client_channel, chr(0)); + } + */ + // currently, there's only one possible value for $data_type_code: NET_SSH2_EXTENDED_DATA_STDERR + list($data_type_code, $data) = Strings::unpackSSH2('Ns', $response); + $this->stdErrorLog .= $data; + if ($skip_extended || $this->quiet_mode) { + continue 2; + } + if ($client_channel == $channel && $this->channel_status[$channel] == NET_SSH2_MSG_CHANNEL_DATA) { + return $data; + } + $this->channel_buffers[$channel][] = chr($type) . $data; + + continue 2; + case NET_SSH2_MSG_CHANNEL_REQUEST: + if ($this->channel_status[$channel] == NET_SSH2_MSG_CHANNEL_CLOSE) { + continue 2; + } + list($value) = Strings::unpackSSH2('s', $response); + switch ($value) { + case 'exit-signal': + list( + , // FALSE + $signal_name, + , // core dumped + $error_message + ) = Strings::unpackSSH2('bsbs', $response); + + $this->errors[] = "SSH_MSG_CHANNEL_REQUEST (exit-signal): $signal_name"; + if (strlen($error_message)) { + $this->errors[count($this->errors) - 1] .= "\r\n$error_message"; + } + + $this->send_binary_packet(pack('CN', NET_SSH2_MSG_CHANNEL_EOF, $this->server_channels[$client_channel])); + $this->send_binary_packet(pack('CN', NET_SSH2_MSG_CHANNEL_CLOSE, $this->server_channels[$channel])); + + $this->channel_status[$channel] = NET_SSH2_MSG_CHANNEL_EOF; + + continue 3; + case 'exit-status': + list(, $this->exit_status) = Strings::unpackSSH2('CN', $response); + + // "The client MAY ignore these messages." + // -- http://tools.ietf.org/html/rfc4254#section-6.10 + + continue 3; + default: + // "Some systems may not implement signals, in which case they SHOULD ignore this message." + // -- http://tools.ietf.org/html/rfc4254#section-6.9 + continue 3; + } + } + + switch ($this->channel_status[$channel]) { + case NET_SSH2_MSG_CHANNEL_OPEN: + switch ($type) { + case NET_SSH2_MSG_CHANNEL_OPEN_CONFIRMATION: + list( + $this->server_channels[$channel], + $window_size, + $this->packet_size_client_to_server[$channel] + ) = Strings::unpackSSH2('NNN', $response); + + if ($window_size < 0) { + $window_size &= 0x7FFFFFFF; + $window_size += 0x80000000; + } + $this->window_size_client_to_server[$channel] = $window_size; + $result = $client_channel == $channel ? true : $this->get_channel_packet($client_channel, $skip_extended); + $this->on_channel_open(); + return $result; + case NET_SSH2_MSG_CHANNEL_OPEN_FAILURE: + $this->disconnect_helper(NET_SSH2_DISCONNECT_BY_APPLICATION); + throw new \RuntimeException('Unable to open channel'); + default: + if ($client_channel == $channel) { + $this->disconnect_helper(NET_SSH2_DISCONNECT_BY_APPLICATION); + throw new \RuntimeException('Unexpected response to open request'); + } + return $this->get_channel_packet($client_channel, $skip_extended); + } + break; + case NET_SSH2_MSG_CHANNEL_REQUEST: + switch ($type) { + case NET_SSH2_MSG_CHANNEL_SUCCESS: + return true; + case NET_SSH2_MSG_CHANNEL_FAILURE: + return false; + case NET_SSH2_MSG_CHANNEL_DATA: + list($data) = Strings::unpackSSH2('s', $response); + $this->channel_buffers[$channel][] = chr($type) . $data; + return $this->get_channel_packet($client_channel, $skip_extended); + default: + $this->disconnect_helper(NET_SSH2_DISCONNECT_BY_APPLICATION); + throw new \RuntimeException('Unable to fulfill channel request'); + } + case NET_SSH2_MSG_CHANNEL_CLOSE: + if ($client_channel == $channel && $type == NET_SSH2_MSG_CHANNEL_CLOSE) { + return true; + } + return $this->get_channel_packet($client_channel, $skip_extended); + } + } + + // ie. $this->channel_status[$channel] == NET_SSH2_MSG_CHANNEL_DATA + + switch ($type) { + case NET_SSH2_MSG_CHANNEL_DATA: + /* + if ($channel == self::CHANNEL_EXEC) { + // SCP requires null packets, such as this, be sent. further, in the case of the ssh.com SSH server + // this actually seems to make things twice as fast. more to the point, the message right after + // SSH_MSG_CHANNEL_DATA (usually SSH_MSG_IGNORE) won't block for as long as it would have otherwise. + // in OpenSSH it slows things down but only by a couple thousandths of a second. + $this->send_channel_packet($channel, chr(0)); + } + */ + list($data) = Strings::unpackSSH2('s', $response); + + if ($channel == self::CHANNEL_AGENT_FORWARD) { + $agent_response = $this->agent->forwardData($data); + if (!is_bool($agent_response)) { + $this->send_channel_packet($channel, $agent_response); + } + break; + } + + if ($client_channel == $channel) { + return $data; + } + $this->channel_buffers[$channel][] = chr($type) . $data; + break; + case NET_SSH2_MSG_CHANNEL_CLOSE: + $this->curTimeout = 5; + + $this->close_channel_bitmap($channel); + + if ($this->channel_status[$channel] != NET_SSH2_MSG_CHANNEL_EOF) { + $this->send_binary_packet(pack('CN', NET_SSH2_MSG_CHANNEL_CLOSE, $this->server_channels[$channel])); + } + + $this->channel_status[$channel] = NET_SSH2_MSG_CHANNEL_CLOSE; + $this->channelCount--; + + if ($client_channel == $channel) { + return true; + } + // fall-through + case NET_SSH2_MSG_CHANNEL_EOF: + break; + default: + $this->disconnect_helper(NET_SSH2_DISCONNECT_BY_APPLICATION); + throw new \RuntimeException("Error reading channel data ($type)"); + } + } + } + + /** + * Sends Binary Packets + * + * See '6. Binary Packet Protocol' of rfc4253 for more info. + * + * @param string $data + * @param string $logged + * @see self::_get_binary_packet() + * @return void + */ + protected function send_binary_packet($data, $logged = null) + { + if (!is_resource($this->fsock) || feof($this->fsock)) { + $this->bitmap = 0; + throw new ConnectionClosedException('Connection closed prematurely'); + } + + if (!isset($logged)) { + $logged = $data; + } + + switch ($this->compress) { + case self::NET_SSH2_COMPRESSION_ZLIB_AT_OPENSSH: + if (!$this->isAuthenticated()) { + break; + } + // fall-through + case self::NET_SSH2_COMPRESSION_ZLIB: + if (!$this->regenerate_compression_context) { + $header = ''; + } else { + $this->regenerate_compression_context = false; + $this->compress_context = deflate_init(ZLIB_ENCODING_RAW, ['window' => 15]); + $header = "\x78\x9C"; + } + if ($this->compress_context) { + $data = $header . deflate_add($this->compress_context, $data, ZLIB_PARTIAL_FLUSH); + } + } + + // 4 (packet length) + 1 (padding length) + 4 (minimal padding amount) == 9 + $packet_length = strlen($data) + 9; + if ($this->encrypt && $this->encrypt->usesNonce()) { + $packet_length -= 4; + } + // round up to the nearest $this->encrypt_block_size + $packet_length += (($this->encrypt_block_size - 1) * $packet_length) % $this->encrypt_block_size; + // subtracting strlen($data) is obvious - subtracting 5 is necessary because of packet_length and padding_length + $padding_length = $packet_length - strlen($data) - 5; + switch (true) { + case $this->encrypt && $this->encrypt->usesNonce(): + case $this->hmac_create instanceof Hash && $this->hmac_create_etm: + $padding_length += 4; + $packet_length += 4; + } + + $padding = Random::string($padding_length); + + // we subtract 4 from packet_length because the packet_length field isn't supposed to include itself + $packet = pack('NCa*', $packet_length - 4, $padding_length, $data . $padding); + + $hmac = ''; + if ($this->hmac_create instanceof Hash && !$this->hmac_create_etm) { + if (($this->hmac_create->getHash() & "\xFF\xFF\xFF\xFF") == 'umac') { + $this->hmac_create->setNonce("\0\0\0\0" . pack('N', $this->send_seq_no)); + $hmac = $this->hmac_create->hash($packet); + } else { + $hmac = $this->hmac_create->hash(pack('Na*', $this->send_seq_no, $packet)); + } + } + + if ($this->encrypt) { + switch ($this->encryptName) { + case '[email protected]': + case '[email protected]': + $this->encrypt->setNonce( + $this->encryptFixedPart . + $this->encryptInvocationCounter + ); + Strings::increment_str($this->encryptInvocationCounter); + $this->encrypt->setAAD($temp = ($packet & "\xFF\xFF\xFF\xFF")); + $packet = $temp . $this->encrypt->encrypt(substr($packet, 4)); + break; + case '[email protected]': + // This should be impossible, but we are checking anyway to narrow the type for Psalm. + if (!($this->encrypt instanceof ChaCha20)) { + throw new \LogicException('$this->encrypt is not a ' . ChaCha20::class); + } + + $nonce = pack('N2', 0, $this->send_seq_no); + + $this->encrypt->setNonce($nonce); + $this->lengthEncrypt->setNonce($nonce); + + $length = $this->lengthEncrypt->encrypt($packet & "\xFF\xFF\xFF\xFF"); + + $this->encrypt->setCounter(0); + // this is the same approach that's implemented in Salsa20::createPoly1305Key() + // but we don't want to use the same AEAD construction that RFC8439 describes + // for ChaCha20-Poly1305 so we won't rely on it (see Salsa20::poly1305()) + $this->encrypt->setPoly1305Key( + $this->encrypt->encrypt(str_repeat("\0", 32)) + ); + $this->encrypt->setAAD($length); + $this->encrypt->setCounter(1); + $packet = $length . $this->encrypt->encrypt(substr($packet, 4)); + break; + default: + $packet = $this->hmac_create instanceof Hash && $this->hmac_create_etm ? + ($packet & "\xFF\xFF\xFF\xFF") . $this->encrypt->encrypt(substr($packet, 4)) : + $this->encrypt->encrypt($packet); + } + } + + if ($this->hmac_create instanceof Hash && $this->hmac_create_etm) { + if (($this->hmac_create->getHash() & "\xFF\xFF\xFF\xFF") == 'umac') { + $this->hmac_create->setNonce("\0\0\0\0" . pack('N', $this->send_seq_no)); + $hmac = $this->hmac_create->hash($packet); + } else { + $hmac = $this->hmac_create->hash(pack('Na*', $this->send_seq_no, $packet)); + } + } + + $this->send_seq_no++; + + $packet .= $this->encrypt && $this->encrypt->usesNonce() ? $this->encrypt->getTag() : $hmac; + + $start = microtime(true); + $sent = @fputs($this->fsock, $packet); + $stop = microtime(true); + + if (defined('NET_SSH2_LOGGING')) { + $current = microtime(true); + $message_number = isset(self::$message_numbers[ord($logged[0])]) ? self::$message_numbers[ord($logged[0])] : 'UNKNOWN (' . ord($logged[0]) . ')'; + $message_number = '-> ' . $message_number . + ' (since last: ' . round($current - $this->last_packet, 4) . ', network: ' . round($stop - $start, 4) . 's)'; + $this->append_log($message_number, $logged); + $this->last_packet = $current; + } + + if (strlen($packet) != $sent) { + $this->bitmap = 0; + $message = $sent === false ? + 'Unable to write ' . strlen($packet) . ' bytes' : + "Only $sent of " . strlen($packet) . " bytes were sent"; + throw new \RuntimeException($message); + } + } + + /** + * Logs data packets + * + * Makes sure that only the last 1MB worth of packets will be logged + * + * @param string $message_number + * @param string $message + */ + private function append_log($message_number, $message) + { + $this->append_log_helper( + NET_SSH2_LOGGING, + $message_number, + $message, + $this->message_number_log, + $this->message_log, + $this->log_size, + $this->realtime_log_file, + $this->realtime_log_wrap, + $this->realtime_log_size + ); + } + + /** + * Logs data packet helper + * + * @param int $constant + * @param string $message_number + * @param string $message + * @param array &$message_number_log + * @param array &$message_log + * @param int &$log_size + * @param resource &$realtime_log_file + * @param bool &$realtime_log_wrap + * @param int &$realtime_log_size + */ + protected function append_log_helper($constant, $message_number, $message, array &$message_number_log, array &$message_log, &$log_size, &$realtime_log_file, &$realtime_log_wrap, &$realtime_log_size) + { + // remove the byte identifying the message type from all but the first two messages (ie. the identification strings) + if (strlen($message_number) > 2) { + Strings::shift($message); + } + + switch ($constant) { + // useful for benchmarks + case self::LOG_SIMPLE: + $message_number_log[] = $message_number; + break; + case self::LOG_SIMPLE_REALTIME: + echo $message_number; + echo PHP_SAPI == 'cli' ? "\r\n" : '<br>'; + @flush(); + @ob_flush(); + break; + // the most useful log for SSH2 + case self::LOG_COMPLEX: + $message_number_log[] = $message_number; + $log_size += strlen($message); + $message_log[] = $message; + while ($log_size > self::LOG_MAX_SIZE) { + $log_size -= strlen(array_shift($message_log)); + array_shift($message_number_log); + } + break; + // dump the output out realtime; packets may be interspersed with non packets, + // passwords won't be filtered out and select other packets may not be correctly + // identified + case self::LOG_REALTIME: + switch (PHP_SAPI) { + case 'cli': + $start = $stop = "\r\n"; + break; + default: + $start = '<pre>'; + $stop = '</pre>'; + } + echo $start . $this->format_log([$message], [$message_number]) . $stop; + @flush(); + @ob_flush(); + break; + // basically the same thing as self::LOG_REALTIME with the caveat that NET_SSH2_LOG_REALTIME_FILENAME + // needs to be defined and that the resultant log file will be capped out at self::LOG_MAX_SIZE. + // the earliest part of the log file is denoted by the first <<< START >>> and is not going to necessarily + // at the beginning of the file + case self::LOG_REALTIME_FILE: + if (!isset($realtime_log_file)) { + // PHP doesn't seem to like using constants in fopen() + $filename = NET_SSH2_LOG_REALTIME_FILENAME; + $fp = fopen($filename, 'w'); + $realtime_log_file = $fp; + } + if (!is_resource($realtime_log_file)) { + break; + } + $entry = $this->format_log([$message], [$message_number]); + if ($realtime_log_wrap) { + $temp = "<<< START >>>\r\n"; + $entry .= $temp; + fseek($realtime_log_file, ftell($realtime_log_file) - strlen($temp)); + } + $realtime_log_size += strlen($entry); + if ($realtime_log_size > self::LOG_MAX_SIZE) { + fseek($realtime_log_file, 0); + $realtime_log_size = strlen($entry); + $realtime_log_wrap = true; + } + fputs($realtime_log_file, $entry); + } + } + + /** + * Sends channel data + * + * Spans multiple SSH_MSG_CHANNEL_DATAs if appropriate + * + * @param int $client_channel + * @param string $data + * @return void + */ + protected function send_channel_packet($client_channel, $data) + { + while (strlen($data)) { + if (!$this->window_size_client_to_server[$client_channel]) { + $this->bitmap ^= self::MASK_WINDOW_ADJUST; + // using an invalid channel will let the buffers be built up for the valid channels + $this->get_channel_packet(-1); + $this->bitmap ^= self::MASK_WINDOW_ADJUST; + } + + /* The maximum amount of data allowed is determined by the maximum + packet size for the channel, and the current window size, whichever + is smaller. + -- http://tools.ietf.org/html/rfc4254#section-5.2 */ + $max_size = min( + $this->packet_size_client_to_server[$client_channel], + $this->window_size_client_to_server[$client_channel] + ); + + $temp = Strings::shift($data, $max_size); + $packet = Strings::packSSH2( + 'CNs', + NET_SSH2_MSG_CHANNEL_DATA, + $this->server_channels[$client_channel], + $temp + ); + $this->window_size_client_to_server[$client_channel] -= strlen($temp); + $this->send_binary_packet($packet); + } + } + + /** + * Closes and flushes a channel + * + * \phpseclib3\Net\SSH2 doesn't properly close most channels. For exec() channels are normally closed by the server + * and for SFTP channels are presumably closed when the client disconnects. This functions is intended + * for SCP more than anything. + * + * @param int $client_channel + * @param bool $want_reply + * @return void + */ + private function close_channel($client_channel, $want_reply = false) + { + // see http://tools.ietf.org/html/rfc4254#section-5.3 + + $this->send_binary_packet(pack('CN', NET_SSH2_MSG_CHANNEL_EOF, $this->server_channels[$client_channel])); + + if (!$want_reply) { + $this->send_binary_packet(pack('CN', NET_SSH2_MSG_CHANNEL_CLOSE, $this->server_channels[$client_channel])); + } + + $this->channel_status[$client_channel] = NET_SSH2_MSG_CHANNEL_CLOSE; + $this->channelCount--; + + $this->curTimeout = 5; + + while (!is_bool($this->get_channel_packet($client_channel))) { + } + + if ($want_reply) { + $this->send_binary_packet(pack('CN', NET_SSH2_MSG_CHANNEL_CLOSE, $this->server_channels[$client_channel])); + } + + $this->close_channel_bitmap($client_channel); + } + + /** + * Maintains execution state bitmap in response to channel closure + * + * @param int $client_channel The channel number to maintain closure status of + * @return void + */ + private function close_channel_bitmap($client_channel) + { + switch ($client_channel) { + case self::CHANNEL_SHELL: + // Shell status has been maintained in the bitmap for backwards + // compatibility sake, but can be removed going forward + if ($this->bitmap & self::MASK_SHELL) { + $this->bitmap &= ~self::MASK_SHELL; + } + break; + } + } + + /** + * Disconnect + * + * @param int $reason + * @return false + */ + protected function disconnect_helper($reason) + { + if ($this->bitmap & self::MASK_CONNECTED) { + $data = Strings::packSSH2('CNss', NET_SSH2_MSG_DISCONNECT, $reason, '', ''); + try { + $this->send_binary_packet($data); + } catch (\Exception $e) { + } + } + + $this->bitmap = 0; + if (is_resource($this->fsock) && get_resource_type($this->fsock) === 'stream') { + fclose($this->fsock); + } + + return false; + } + + /** + * Define Array + * + * Takes any number of arrays whose indices are integers and whose values are strings and defines a bunch of + * named constants from it, using the value as the name of the constant and the index as the value of the constant. + * If any of the constants that would be defined already exists, none of the constants will be defined. + * + * @param mixed[] ...$args + * @access protected + */ + protected static function define_array(...$args) + { + foreach ($args as $arg) { + foreach ($arg as $key => $value) { + if (!defined($value)) { + define($value, $key); + } else { + break 2; + } + } + } + } + + /** + * Returns a log of the packets that have been sent and received. + * + * Returns a string if NET_SSH2_LOGGING == self::LOG_COMPLEX, an array if NET_SSH2_LOGGING == self::LOG_SIMPLE and false if !defined('NET_SSH2_LOGGING') + * + * @return array|false|string + */ + public function getLog() + { + if (!defined('NET_SSH2_LOGGING')) { + return false; + } + + switch (NET_SSH2_LOGGING) { + case self::LOG_SIMPLE: + return $this->message_number_log; + case self::LOG_COMPLEX: + $log = $this->format_log($this->message_log, $this->message_number_log); + return PHP_SAPI == 'cli' ? $log : '<pre>' . $log . '</pre>'; + default: + return false; + } + } + + /** + * Formats a log for printing + * + * @param array $message_log + * @param array $message_number_log + * @return string + */ + protected function format_log(array $message_log, array $message_number_log) + { + $output = ''; + for ($i = 0; $i < count($message_log); $i++) { + $output .= $message_number_log[$i] . "\r\n"; + $current_log = $message_log[$i]; + $j = 0; + do { + if (strlen($current_log)) { + $output .= str_pad(dechex($j), 7, '0', STR_PAD_LEFT) . '0 '; + } + $fragment = Strings::shift($current_log, $this->log_short_width); + $hex = substr(preg_replace_callback('#.#s', function ($matches) { + return $this->log_boundary . str_pad(dechex(ord($matches[0])), 2, '0', STR_PAD_LEFT); + }, $fragment), strlen($this->log_boundary)); + // replace non ASCII printable characters with dots + // http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters + // also replace < with a . since < messes up the output on web browsers + $raw = preg_replace('#[^\x20-\x7E]|<#', '.', $fragment); + $output .= str_pad($hex, $this->log_long_width - $this->log_short_width, ' ') . $raw . "\r\n"; + $j++; + } while (strlen($current_log)); + $output .= "\r\n"; + } + + return $output; + } + + /** + * Helper function for agent->on_channel_open() + * + * Used when channels are created to inform agent + * of said channel opening. Must be called after + * channel open confirmation received + * + */ + private function on_channel_open() + { + if (isset($this->agent)) { + $this->agent->registerChannelOpen($this); + } + } + + /** + * Returns the first value of the intersection of two arrays or false if + * the intersection is empty. The order is defined by the first parameter. + * + * @param array $array1 + * @param array $array2 + * @return mixed False if intersection is empty, else intersected value. + */ + private static function array_intersect_first(array $array1, array $array2) + { + foreach ($array1 as $value) { + if (in_array($value, $array2)) { + return $value; + } + } + return false; + } + + /** + * Returns all errors + * + * @return string[] + */ + public function getErrors() + { + return $this->errors; + } + + /** + * Returns the last error + * + * @return string + */ + public function getLastError() + { + $count = count($this->errors); + + if ($count > 0) { + return $this->errors[$count - 1]; + } + } + + /** + * Return the server identification. + * + * @return string|false + */ + public function getServerIdentification() + { + $this->connect(); + + return $this->server_identifier; + } + + /** + * Returns a list of algorithms the server supports + * + * @return array + */ + public function getServerAlgorithms() + { + $this->connect(); + + 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 + ] + ]; + } + + /** + * Returns a list of KEX algorithms that phpseclib supports + * + * @return array + */ + public static function getSupportedKEXAlgorithms() + { + $kex_algorithms = [ + // Elliptic Curve Diffie-Hellman Key Agreement (ECDH) using + // Curve25519. See doc/[email protected] in the + // libssh repository for more information. + 'curve25519-sha256', + '[email protected]', + + 'ecdh-sha2-nistp256', // RFC 5656 + 'ecdh-sha2-nistp384', // RFC 5656 + 'ecdh-sha2-nistp521', // RFC 5656 + + 'diffie-hellman-group-exchange-sha256',// RFC 4419 + 'diffie-hellman-group-exchange-sha1', // RFC 4419 + + // Diffie-Hellman Key Agreement (DH) using integer modulo prime + // groups. + 'diffie-hellman-group14-sha256', + 'diffie-hellman-group14-sha1', // REQUIRED + 'diffie-hellman-group15-sha512', + 'diffie-hellman-group16-sha512', + 'diffie-hellman-group17-sha512', + 'diffie-hellman-group18-sha512', + + 'diffie-hellman-group1-sha1', // REQUIRED + ]; + + return $kex_algorithms; + } + + /** + * Returns a list of host key algorithms that phpseclib supports + * + * @return array + */ + public static function getSupportedHostKeyAlgorithms() + { + return [ + 'ssh-ed25519', // https://tools.ietf.org/html/draft-ietf-curdle-ssh-ed25519-02 + 'ecdsa-sha2-nistp256', // RFC 5656 + 'ecdsa-sha2-nistp384', // RFC 5656 + 'ecdsa-sha2-nistp521', // RFC 5656 + 'rsa-sha2-256', // RFC 8332 + 'rsa-sha2-512', // RFC 8332 + 'ssh-rsa', // RECOMMENDED sign Raw RSA Key + 'ssh-dss' // REQUIRED sign Raw DSS Key + ]; + } + + /** + * Returns a list of symmetric key algorithms that phpseclib supports + * + * @return array + */ + public static function getSupportedEncryptionAlgorithms() + { + $algos = [ + // from <https://tools.ietf.org/html/rfc5647>: + '[email protected]', + '[email protected]', + + // from <http://tools.ietf.org/html/rfc4345#section-4>: + 'arcfour256', + 'arcfour128', + + //'arcfour', // OPTIONAL the ARCFOUR stream cipher with a 128-bit key + + // CTR modes from <http://tools.ietf.org/html/rfc4344#section-4>: + 'aes128-ctr', // RECOMMENDED AES (Rijndael) in SDCTR mode, with 128-bit key + 'aes192-ctr', // RECOMMENDED AES with 192-bit key + 'aes256-ctr', // RECOMMENDED AES with 256-bit key + + // from <https://github.com/openssh/openssh-portable/blob/001aa55/PROTOCOL.chacha20poly1305>: + // one of the big benefits of chacha20-poly1305 is speed. the problem is... + // libsodium doesn't generate the poly1305 keys in the way ssh does and openssl's PHP bindings don't even + // seem to support poly1305 currently. so even if libsodium or openssl are being used for the chacha20 + // part, pure-PHP has to be used for the poly1305 part and that's gonna cause a big slow down. + // speed-wise it winds up being faster to use AES (when openssl or mcrypt are available) and some HMAC + // (which is always gonna be super fast to compute thanks to the hash extension, which + // "is bundled and compiled into PHP by default") + '[email protected]', + + 'twofish128-ctr', // OPTIONAL Twofish in SDCTR mode, with 128-bit key + 'twofish192-ctr', // OPTIONAL Twofish with 192-bit key + 'twofish256-ctr', // OPTIONAL Twofish with 256-bit key + + 'aes128-cbc', // RECOMMENDED AES with a 128-bit key + 'aes192-cbc', // OPTIONAL AES with a 192-bit key + 'aes256-cbc', // OPTIONAL AES in CBC mode, with a 256-bit key + + 'twofish128-cbc', // OPTIONAL Twofish with a 128-bit key + 'twofish192-cbc', // OPTIONAL Twofish with a 192-bit key + 'twofish256-cbc', + 'twofish-cbc', // OPTIONAL alias for "twofish256-cbc" + // (this is being retained for historical reasons) + + 'blowfish-ctr', // OPTIONAL Blowfish in SDCTR mode + + 'blowfish-cbc', // OPTIONAL Blowfish in CBC mode + + '3des-ctr', // RECOMMENDED Three-key 3DES in SDCTR mode + + '3des-cbc', // REQUIRED three-key 3DES in CBC mode + + //'none' // OPTIONAL no encryption; NOT RECOMMENDED + ]; + + if (self::$crypto_engine) { + $engines = [self::$crypto_engine]; + } else { + $engines = [ + 'libsodium', + 'OpenSSL (GCM)', + 'OpenSSL', + 'mcrypt', + 'Eval', + 'PHP' + ]; + } + + $ciphers = []; + + foreach ($engines as $engine) { + foreach ($algos as $algo) { + $obj = self::encryption_algorithm_to_crypt_instance($algo); + if ($obj instanceof Rijndael) { + $obj->setKeyLength(preg_replace('#[^\d]#', '', $algo)); + } + switch ($algo) { + case '[email protected]': + case 'arcfour128': + case 'arcfour256': + if ($engine != 'Eval') { + continue 2; + } + break; + case '[email protected]': + case '[email protected]': + if ($engine == 'OpenSSL') { + continue 2; + } + $obj->setNonce('dummydummydu'); + } + if ($obj->isValidEngine($engine)) { + $algos = array_diff($algos, [$algo]); + $ciphers[] = $algo; + } + } + } + + return $ciphers; + } + + /** + * Returns a list of MAC algorithms that phpseclib supports + * + * @return array + */ + public static function getSupportedMACAlgorithms() + { + return [ + '[email protected]', + '[email protected]', + '[email protected]', + '[email protected]', + '[email protected]', + + // from <http://www.ietf.org/rfc/rfc6668.txt>: + 'hmac-sha2-256',// RECOMMENDED HMAC-SHA256 (digest length = key length = 32) + 'hmac-sha2-512',// OPTIONAL HMAC-SHA512 (digest length = key length = 64) + + // from <https://tools.ietf.org/html/draft-miller-secsh-umac-01>: + '[email protected]', + '[email protected]', + + 'hmac-sha1-96', // RECOMMENDED first 96 bits of HMAC-SHA1 (digest length = 12, key length = 20) + 'hmac-sha1', // REQUIRED HMAC-SHA1 (digest length = key length = 20) + 'hmac-md5-96', // OPTIONAL first 96 bits of HMAC-MD5 (digest length = 12, key length = 16) + 'hmac-md5', // OPTIONAL HMAC-MD5 (digest length = key length = 16) + //'none' // OPTIONAL no MAC; NOT RECOMMENDED + ]; + } + + /** + * Returns a list of compression algorithms that phpseclib supports + * + * @return array + */ + public static function getSupportedCompressionAlgorithms() + { + $algos = ['none']; // REQUIRED no compression + if (function_exists('deflate_init')) { + $algos[] = '[email protected]'; // https://datatracker.ietf.org/doc/html/draft-miller-secsh-compression-delayed + $algos[] = 'zlib'; + } + return $algos; + } + + /** + * Return list of negotiated algorithms + * + * Uses the same format as https://www.php.net/ssh2-methods-negotiated + * + * @return array + */ + public function getAlgorithmsNegotiated() + { + $this->connect(); + + $compression_map = [ + self::NET_SSH2_COMPRESSION_NONE => 'none', + self::NET_SSH2_COMPRESSION_ZLIB => 'zlib', + self::NET_SSH2_COMPRESSION_ZLIB_AT_OPENSSH => '[email protected]' + ]; + + return [ + 'kex' => $this->kex_algorithm, + 'hostkey' => $this->signature_format, + 'client_to_server' => [ + 'crypt' => $this->encryptName, + 'mac' => $this->hmac_create_name, + 'comp' => $compression_map[$this->compress], + ], + 'server_to_client' => [ + 'crypt' => $this->decryptName, + 'mac' => $this->hmac_check_name, + 'comp' => $compression_map[$this->decompress], + ] + ]; + } + + /** + * Force multiple channels (even if phpseclib has decided to disable them) + */ + public function forceMultipleChannels() + { + $this->errorOnMultipleChannels = false; + } + + /** + * Allows you to set the terminal + * + * @param string $term + */ + public function setTerminal($term) + { + $this->term = $term; + } + + /** + * 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 + */ + 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. + * + * Quoting from the RFC, "in some jurisdictions, sending a warning message before + * authentication may be relevant for getting legal protection." + * + * @return string + */ + public function getBannerMessage() + { + return $this->banner_message; + } + + /** + * Returns the server public host key. + * + * Caching this the first time you connect to a server and checking the result on subsequent connections + * is recommended. Returns false if the server signature is not signed correctly with the public host key. + * + * @return string|false + * @throws \RuntimeException on badly formatted keys + * @throws \phpseclib3\Exception\NoSupportedAlgorithmsException when the key isn't in a supported format + */ + public function getServerPublicHostKey() + { + if (!($this->bitmap & self::MASK_CONSTRUCTOR)) { + $this->connect(); + } + + $signature = $this->signature; + $server_public_host_key = base64_encode($this->server_public_host_key); + + if ($this->signature_validated) { + return $this->bitmap ? + $this->signature_format . ' ' . $server_public_host_key : + false; + } + + $this->signature_validated = true; + + switch ($this->signature_format) { + case 'ssh-ed25519': + case 'ecdsa-sha2-nistp256': + case 'ecdsa-sha2-nistp384': + case 'ecdsa-sha2-nistp521': + $key = EC::loadFormat('OpenSSH', $server_public_host_key) + ->withSignatureFormat('SSH2'); + switch ($this->signature_format) { + case 'ssh-ed25519': + $hash = 'sha512'; + break; + case 'ecdsa-sha2-nistp256': + $hash = 'sha256'; + break; + case 'ecdsa-sha2-nistp384': + $hash = 'sha384'; + break; + case 'ecdsa-sha2-nistp521': + $hash = 'sha512'; + } + $key = $key->withHash($hash); + break; + case 'ssh-dss': + $key = DSA::loadFormat('OpenSSH', $server_public_host_key) + ->withSignatureFormat('SSH2') + ->withHash('sha1'); + break; + case 'ssh-rsa': + case 'rsa-sha2-256': + case 'rsa-sha2-512': + // could be ssh-rsa, rsa-sha2-256, rsa-sha2-512 + // we don't check here because we already checked in key_exchange + // some signatures have the type embedded within the message and some don't + list(, $signature) = Strings::unpackSSH2('ss', $signature); + + $key = RSA::loadFormat('OpenSSH', $server_public_host_key) + ->withPadding(RSA::SIGNATURE_PKCS1); + switch ($this->signature_format) { + case 'rsa-sha2-512': + $hash = 'sha512'; + break; + case 'rsa-sha2-256': + $hash = 'sha256'; + break; + //case 'ssh-rsa': + default: + $hash = 'sha1'; + } + $key = $key->withHash($hash); + break; + default: + $this->disconnect_helper(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE); + throw new NoSupportedAlgorithmsException('Unsupported signature format'); + } + + if (!$key->verify($this->exchange_hash, $signature)) { + return $this->disconnect_helper(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE); + }; + + return $this->signature_format . ' ' . $server_public_host_key; + } + + /** + * Returns the exit status of an SSH command or false. + * + * @return false|int + */ + public function getExitStatus() + { + if (is_null($this->exit_status)) { + return false; + } + return $this->exit_status; + } + + /** + * Returns the number of columns for the terminal window size. + * + * @return int + */ + public function getWindowColumns() + { + return $this->windowColumns; + } + + /** + * Returns the number of rows for the terminal window size. + * + * @return int + */ + public function getWindowRows() + { + return $this->windowRows; + } + + /** + * Sets the number of columns for the terminal window size. + * + * @param int $value + */ + public function setWindowColumns($value) + { + $this->windowColumns = $value; + } + + /** + * Sets the number of rows for the terminal window size. + * + * @param int $value + */ + public function setWindowRows($value) + { + $this->windowRows = $value; + } + + /** + * Sets the number of columns and rows for the terminal window size. + * + * @param int $columns + * @param int $rows + */ + public function setWindowSize($columns = 80, $rows = 24) + { + $this->windowColumns = $columns; + $this->windowRows = $rows; + } + + /** + * To String Magic Method + * + * @return string + */ + #[\ReturnTypeWillChange] + public function __toString() + { + return $this->getResourceId(); + } + + /** + * Get Resource ID + * + * We use {} because that symbols should not be in URL according to + * {@link http://tools.ietf.org/html/rfc3986#section-2 RFC}. + * It will safe us from any conflicts, because otherwise regexp will + * match all alphanumeric domains. + * + * @return string + */ + public function getResourceId() + { + return '{' . spl_object_hash($this) . '}'; + } + + /** + * Return existing connection + * + * @param string $id + * + * @return bool|SSH2 will return false if no such connection + */ + public static function getConnectionByResourceId($id) + { + if (isset(self::$connections[$id])) { + return self::$connections[$id] instanceof \WeakReference ? self::$connections[$id]->get() : self::$connections[$id]; + } + return false; + } + + /** + * Return all excising connections + * + * @return array<string, SSH2> + */ + public static function getConnections() + { + if (!class_exists('WeakReference')) { + /** @var array<string, SSH2> */ + return self::$connections; + } + $temp = []; + foreach (self::$connections as $key => $ref) { + $temp[$key] = $ref->get(); + } + return $temp; + } + + /* + * Update packet types in log history + * + * @param string $old + * @param string $new + */ + private function updateLogHistory($old, $new) + { + if (defined('NET_SSH2_LOGGING') && NET_SSH2_LOGGING == self::LOG_COMPLEX) { + $this->message_number_log[count($this->message_number_log) - 1] = str_replace( + $old, + $new, + $this->message_number_log[count($this->message_number_log) - 1] + ); + } + } + + /** + * Return the list of authentication methods that may productively continue authentication. + * + * @see https://tools.ietf.org/html/rfc4252#section-5.1 + * @return array|null + */ + public function getAuthMethodsToContinue() + { + return $this->auth_methods_to_continue; + } + + /** + * Enables "smart" multi-factor authentication (MFA) + */ + public function enableSmartMFA() + { + $this->smartMFA = true; + } + + /** + * Disables "smart" multi-factor authentication (MFA) + */ + public function disableSmartMFA() + { + $this->smartMFA = false; + } +} |