/**
* 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 Mixed
* @access public
*/
function getServerPublicHostKey()
{
$signature = $this->signature;
$server_public_host_key = $this->server_public_host_key;
extract(unpack('Nlength', $this->_string_shift($server_public_host_key, 4)));
$this->_string_shift($server_public_host_key, $length);
if ($this->signature_validated) {
return $this->bitmap ? $this->signature_format . ' ' . base64_encode($this->server_public_host_key) : false;
}
$this->signature_validated = true;
switch ($this->signature_format) {
case 'ssh-dss':
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$p = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$q = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$g = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$y = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
/* The value for 'dss_signature_blob' is encoded as a string containing
r, followed by s (which are 160-bit integers, without lengths or
padding, unsigned, and in network byte order). */
$temp = unpack('Nlength', $this->_string_shift($signature, 4));
if ($temp['length'] != 40) {
user_error('Invalid signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$r = new Math_BigInteger($this->_string_shift($signature, 20), 256);
$s = new Math_BigInteger($this->_string_shift($signature, 20), 256);
if ($r->compare($q) >= 0 || $s->compare($q) >= 0) {
user_error('Invalid signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$w = $s->modInverse($q);
$u1 = $w->multiply(new Math_BigInteger(sha1($this->exchange_hash), 16));
list(, $u1) = $u1->divide($q);
$u2 = $w->multiply($r);
list(, $u2) = $u2->divide($q);
$g = $g->modPow($u1, $p);
$y = $y->modPow($u2, $p);
$v = $g->multiply($y);
list(, $v) = $v->divide($p);
list(, $v) = $v->divide($q);
if (!$v->equals($r)) {
user_error('Bad server signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
}
break;
case 'ssh-rsa':
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$e = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
$n = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
$nLength = $temp['length'];
/*
$temp = unpack('Nlength', $this->_string_shift($signature, 4));
$signature = $this->_string_shift($signature, $temp['length']);
if (!class_exists('Crypt_RSA')) {
require_once('Crypt/RSA.php');
}
$rsa = new Crypt_RSA();
$rsa->setSignatureMode(CRYPT_RSA_SIGNATURE_PKCS1);
$rsa->loadKey(array('e' => $e, 'n' => $n), CRYPT_RSA_PUBLIC_FORMAT_RAW);
if (!$rsa->verify($this->exchange_hash, $signature)) {
user_error('Bad server signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
}
*/
$temp = unpack('Nlength', $this->_string_shift($signature, 4));
$s = new Math_BigInteger($this->_string_shift($signature, $temp['length']), 256);
// validate an RSA signature per "8.2 RSASSA-PKCS1-v1_5", "5.2.2 RSAVP1", and "9.1 EMSA-PSS" in the
// following URL:
// ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-1/pkcs-1v2-1.pdf
// also, see SSHRSA.c (rsa2_verifysig) in PuTTy's source.
if ($s->compare(new Math_BigInteger()) < 0 || $s->compare($n->subtract(new Math_BigInteger(1))) > 0) {
user_error('Invalid signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
$s = $s->modPow($e, $n);
$s = $s->toBytes();
$h = pack('N4H*', 0x302130, 0x906052b, 0xe03021a, 0x5000414, sha1($this->exchange_hash));
$h = chr(0x1) . str_repeat(chr(0xff), $nLength - 3 - strlen($h)) . $h;
if ($s != $h) {
user_error('Bad server signature', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
}
break;
default:
user_error('Unsupported signature format', E_USER_NOTICE);
return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
}
return $this->signature_format . ' ' . base64_encode($this->server_public_host_key);
}
/**
* Pure-PHP implementation of SHA384 and SHA512
*
* @access private
* @param String $text
*/
function _sha512($m)
{
if (!class_exists('Math_BigInteger')) {
require_once 'Math/BigInteger.php';
}
static $init384, $init512, $k;
if (!isset($k)) {
// Initialize variables
$init384 = array('cbbb9d5dc1059ed8', '629a292a367cd507', '9159015a3070dd17', '152fecd8f70e5939', '67332667ffc00b31', '8eb44a8768581511', 'db0c2e0d64f98fa7', '47b5481dbefa4fa4');
$init512 = array('6a09e667f3bcc908', 'bb67ae8584caa73b', '3c6ef372fe94f82b', 'a54ff53a5f1d36f1', '510e527fade682d1', '9b05688c2b3e6c1f', '1f83d9abfb41bd6b', '5be0cd19137e2179');
for ($i = 0; $i < 8; $i++) {
$init384[$i] = new Math_BigInteger($init384[$i], 16);
$init384[$i]->setPrecision(64);
$init512[$i] = new Math_BigInteger($init512[$i], 16);
$init512[$i]->setPrecision(64);
}
// Initialize table of round constants
// (first 64 bits of the fractional parts of the cube roots of the first 80 primes 2..409)
$k = array('428a2f98d728ae22', '7137449123ef65cd', 'b5c0fbcfec4d3b2f', 'e9b5dba58189dbbc', '3956c25bf348b538', '59f111f1b605d019', '923f82a4af194f9b', 'ab1c5ed5da6d8118', 'd807aa98a3030242', '12835b0145706fbe', '243185be4ee4b28c', '550c7dc3d5ffb4e2', '72be5d74f27b896f', '80deb1fe3b1696b1', '9bdc06a725c71235', 'c19bf174cf692694', 'e49b69c19ef14ad2', 'efbe4786384f25e3', '0fc19dc68b8cd5b5', '240ca1cc77ac9c65', '2de92c6f592b0275', '4a7484aa6ea6e483', '5cb0a9dcbd41fbd4', '76f988da831153b5', '983e5152ee66dfab', 'a831c66d2db43210', 'b00327c898fb213f', 'bf597fc7beef0ee4', 'c6e00bf33da88fc2', 'd5a79147930aa725', '06ca6351e003826f', '142929670a0e6e70', '27b70a8546d22ffc', '2e1b21385c26c926', '4d2c6dfc5ac42aed', '53380d139d95b3df', '650a73548baf63de', '766a0abb3c77b2a8', '81c2c92e47edaee6', '92722c851482353b', 'a2bfe8a14cf10364', 'a81a664bbc423001', 'c24b8b70d0f89791', 'c76c51a30654be30', 'd192e819d6ef5218', 'd69906245565a910', 'f40e35855771202a', '106aa07032bbd1b8', '19a4c116b8d2d0c8', '1e376c085141ab53', '2748774cdf8eeb99', '34b0bcb5e19b48a8', '391c0cb3c5c95a63', '4ed8aa4ae3418acb', '5b9cca4f7763e373', '682e6ff3d6b2b8a3', '748f82ee5defb2fc', '78a5636f43172f60', '84c87814a1f0ab72', '8cc702081a6439ec', '90befffa23631e28', 'a4506cebde82bde9', 'bef9a3f7b2c67915', 'c67178f2e372532b', 'ca273eceea26619c', 'd186b8c721c0c207', 'eada7dd6cde0eb1e', 'f57d4f7fee6ed178', '06f067aa72176fba', '0a637dc5a2c898a6', '113f9804bef90dae', '1b710b35131c471b', '28db77f523047d84', '32caab7b40c72493', '3c9ebe0a15c9bebc', '431d67c49c100d4c', '4cc5d4becb3e42b6', '597f299cfc657e2a', '5fcb6fab3ad6faec', '6c44198c4a475817');
for ($i = 0; $i < 80; $i++) {
$k[$i] = new Math_BigInteger($k[$i], 16);
}
}
$hash = $this->l == 48 ? $init384 : $init512;
// Pre-processing
$length = strlen($m);
// to round to nearest 112 mod 128, we'll add 128 - (length + (128 - 112)) % 128
$m .= str_repeat(chr(0), 128 - ($length + 16 & 0x7f));
$m[$length] = chr(0x80);
// we don't support hashing strings 512MB long
$m .= pack('N4', 0, 0, 0, $length << 3);
// Process the message in successive 1024-bit chunks
$chunks = str_split($m, 128);
foreach ($chunks as $chunk) {
$w = array();
for ($i = 0; $i < 16; $i++) {
$temp = new Math_BigInteger($this->_string_shift($chunk, 8), 256);
$temp->setPrecision(64);
$w[] = $temp;
}
// Extend the sixteen 32-bit words into eighty 32-bit words
for ($i = 16; $i < 80; $i++) {
$temp = array($w[$i - 15]->bitwise_rightRotate(1), $w[$i - 15]->bitwise_rightRotate(8), $w[$i - 15]->bitwise_rightShift(7));
$s0 = $temp[0]->bitwise_xor($temp[1]);
$s0 = $s0->bitwise_xor($temp[2]);
$temp = array($w[$i - 2]->bitwise_rightRotate(19), $w[$i - 2]->bitwise_rightRotate(61), $w[$i - 2]->bitwise_rightShift(6));
$s1 = $temp[0]->bitwise_xor($temp[1]);
$s1 = $s1->bitwise_xor($temp[2]);
$w[$i] = $w[$i - 16]->copy();
$w[$i] = $w[$i]->add($s0);
$w[$i] = $w[$i]->add($w[$i - 7]);
$w[$i] = $w[$i]->add($s1);
}
// Initialize hash value for this chunk
$a = $hash[0]->copy();
$b = $hash[1]->copy();
$c = $hash[2]->copy();
$d = $hash[3]->copy();
$e = $hash[4]->copy();
$f = $hash[5]->copy();
$g = $hash[6]->copy();
$h = $hash[7]->copy();
// Main loop
for ($i = 0; $i < 80; $i++) {
$temp = array($a->bitwise_rightRotate(28), $a->bitwise_rightRotate(34), $a->bitwise_rightRotate(39));
$s0 = $temp[0]->bitwise_xor($temp[1]);
$s0 = $s0->bitwise_xor($temp[2]);
$temp = array($a->bitwise_and($b), $a->bitwise_and($c), $b->bitwise_and($c));
$maj = $temp[0]->bitwise_xor($temp[1]);
$maj = $maj->bitwise_xor($temp[2]);
$t2 = $s0->add($maj);
$temp = array($e->bitwise_rightRotate(14), $e->bitwise_rightRotate(18), $e->bitwise_rightRotate(41));
$s1 = $temp[0]->bitwise_xor($temp[1]);
$s1 = $s1->bitwise_xor($temp[2]);
$temp = array($e->bitwise_and($f), $g->bitwise_and($e->bitwise_not()));
$ch = $temp[0]->bitwise_xor($temp[1]);
$t1 = $h->add($s1);
$t1 = $t1->add($ch);
$t1 = $t1->add($k[$i]);
$t1 = $t1->add($w[$i]);
$h = $g->copy();
$g = $f->copy();
$f = $e->copy();
$e = $d->add($t1);
$d = $c->copy();
$c = $b->copy();
$b = $a->copy();
$a = $t1->add($t2);
}
// Add this chunk's hash to result so far
$hash = array($hash[0]->add($a), $hash[1]->add($b), $hash[2]->add($c), $hash[3]->add($d), $hash[4]->add($e), $hash[5]->add($f), $hash[6]->add($g), $hash[7]->add($h));
}
// Produce the final hash value (big-endian)
// (Crypt_Hash::hash() trims the output for hashes but not for HMACs. as such, we trim the output here)
$temp = $hash[0]->toBytes() . $hash[1]->toBytes() . $hash[2]->toBytes() . $hash[3]->toBytes() . $hash[4]->toBytes() . $hash[5]->toBytes();
if ($this->l != 48) {
$temp .= $hash[6]->toBytes() . $hash[7]->toBytes();
}
return $temp;
}
/**
* RSAVP1
*
* See {@link http://tools.ietf.org/html/rfc3447#section-5.2.2 RFC3447#section-5.2.2}.
*
* @access private
* @param Math_BigInteger $s
* @return Math_BigInteger
*/
function _rsavp1($s)
{
if ($s->compare($this->zero) < 0 || $s->compare($this->modulus) > 0) {
user_error('Signature representative out of range', E_USER_NOTICE);
return false;
}
return $this->_exponentiate($s);
}
/**
* Default Constructor.
*
* Connects to an SSHv1 server
*
* @param String $host
* @param optional Integer $port
* @param optional Integer $timeout
* @param optional Integer $cipher
* @return Net_SSH1
* @access public
*/
function __construct($host, $port = 22, $timeout = 10, $cipher = NET_SSH1_CIPHER_3DES)
{
$this->protocol_flags = array(1 => 'NET_SSH1_MSG_DISCONNECT', 2 => 'NET_SSH1_SMSG_PUBLIC_KEY', 3 => 'NET_SSH1_CMSG_SESSION_KEY', 4 => 'NET_SSH1_CMSG_USER', 9 => 'NET_SSH1_CMSG_AUTH_PASSWORD', 10 => 'NET_SSH1_CMSG_REQUEST_PTY', 12 => 'NET_SSH1_CMSG_EXEC_SHELL', 13 => 'NET_SSH1_CMSG_EXEC_CMD', 14 => 'NET_SSH1_SMSG_SUCCESS', 15 => 'NET_SSH1_SMSG_FAILURE', 16 => 'NET_SSH1_CMSG_STDIN_DATA', 17 => 'NET_SSH1_SMSG_STDOUT_DATA', 18 => 'NET_SSH1_SMSG_STDERR_DATA', 19 => 'NET_SSH1_CMSG_EOF', 20 => 'NET_SSH1_SMSG_EXITSTATUS', 33 => 'NET_SSH1_CMSG_EXIT_CONFIRMATION');
$this->_define_array($this->protocol_flags);
$this->fsock = @fsockopen($host, $port, $errno, $errstr, $timeout);
if (!$this->fsock) {
user_error(rtrim("Cannot connect to {$host}. Error {$errno}. {$errstr}"), E_USER_NOTICE);
return;
}
$this->server_identification = $init_line = fgets($this->fsock, 255);
if (defined('NET_SSH1_LOGGING')) {
$this->protocol_flags_log[] = '<-';
$this->protocol_flags_log[] = '->';
if (NET_SSH1_LOGGING == NET_SSH1_LOG_COMPLEX) {
$this->message_log[] = $this->server_identification;
$this->message_log[] = $this->identifier . "\r\n";
}
}
if (!preg_match('#SSH-([0-9\\.]+)-(.+)#', $init_line, $parts)) {
user_error('Can only connect to SSH servers', E_USER_NOTICE);
return;
}
if ($parts[1][0] != 1) {
user_error("Cannot connect to SSH {$parts['1']} servers", E_USER_NOTICE);
return;
}
fputs($this->fsock, $this->identifier . "\r\n");
$response = $this->_get_binary_packet();
if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_PUBLIC_KEY) {
user_error('Expected SSH_SMSG_PUBLIC_KEY', E_USER_NOTICE);
return;
}
$anti_spoofing_cookie = $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 8);
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$server_key_public_exponent = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->server_key_public_exponent = $server_key_public_exponent;
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$server_key_public_modulus = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->server_key_public_modulus = $server_key_public_modulus;
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$host_key_public_exponent = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->host_key_public_exponent = $host_key_public_exponent;
$temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
$host_key_public_modulus = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
$this->host_key_public_modulus = $host_key_public_modulus;
$this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
// get a list of the supported ciphers
extract(unpack('Nsupported_ciphers_mask', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4)));
foreach ($this->supported_ciphers as $mask => $name) {
if (($supported_ciphers_mask & 1 << $mask) == 0) {
unset($this->supported_ciphers[$mask]);
}
}
// get a list of the supported authentications
extract(unpack('Nsupported_authentications_mask', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4)));
foreach ($this->supported_authentications as $mask => $name) {
if (($supported_authentications_mask & 1 << $mask) == 0) {
unset($this->supported_authentications[$mask]);
}
}
$session_id = pack('H*', md5($host_key_public_modulus->toBytes() . $server_key_public_modulus->toBytes() . $anti_spoofing_cookie));
$session_key = '';
for ($i = 0; $i < 32; $i++) {
$session_key .= chr(crypt_random(0, 255));
}
$double_encrypted_session_key = $session_key ^ str_pad($session_id, 32, chr(0));
if ($server_key_public_modulus->compare($host_key_public_modulus) < 0) {
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($server_key_public_exponent, $server_key_public_modulus));
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($host_key_public_exponent, $host_key_public_modulus));
} else {
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($host_key_public_exponent, $host_key_public_modulus));
$double_encrypted_session_key = $this->_rsa_crypt($double_encrypted_session_key, array($server_key_public_exponent, $server_key_public_modulus));
}
$cipher = isset($this->supported_ciphers[$cipher]) ? $cipher : NET_SSH1_CIPHER_3DES;
$data = pack('C2a*na*N', NET_SSH1_CMSG_SESSION_KEY, $cipher, $anti_spoofing_cookie, 8 * strlen($double_encrypted_session_key), $double_encrypted_session_key, 0);
if (!$this->_send_binary_packet($data)) {
user_error('Error sending SSH_CMSG_SESSION_KEY', E_USER_NOTICE);
return;
}
switch ($cipher) {
//case NET_SSH1_CIPHER_NONE:
// $this->crypto = new Crypt_Null();
// break;
case NET_SSH1_CIPHER_DES:
$this->crypto = new Crypt_DES();
$this->crypto->disablePadding();
$this->crypto->enableContinuousBuffer();
$this->crypto->setKey(substr($session_key, 0, 8));
break;
case NET_SSH1_CIPHER_3DES:
$this->crypto = new Crypt_TripleDES(CRYPT_DES_MODE_3CBC);
$this->crypto->disablePadding();
$this->crypto->enableContinuousBuffer();
$this->crypto->setKey(substr($session_key, 0, 24));
break;
//case NET_SSH1_CIPHER_RC4:
// $this->crypto = new Crypt_RC4();
// $this->crypto->enableContinuousBuffer();
// $this->crypto->setKey(substr($session_key, 0, 16));
// break;
}
$response = $this->_get_binary_packet();
if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_SUCCESS) {
user_error('Expected SSH_SMSG_SUCCESS', E_USER_NOTICE);
return;
}
$this->bitmap = NET_SSH1_MASK_CONSTRUCTOR;
}
