public function setPublicKey($key = false, $type = false)
{
if ($key === false && !empty($this->modulus)) {
$this->publicExponent = $this->exponent;
return true;
}
if ($type === false) {
$types = array(CRYPT_RSA_PUBLIC_FORMAT_RAW, CRYPT_RSA_PUBLIC_FORMAT_PKCS1, CRYPT_RSA_PUBLIC_FORMAT_XML, CRYPT_RSA_PUBLIC_FORMAT_OPENSSH);
foreach ($types as $type) {
$components = $this->_parseKey($key, $type);
if ($components !== false) {
break;
}
}
} else {
$components = $this->_parseKey($key, $type);
}
if ($components === false) {
return false;
}
if (empty($this->modulus) || !$this->modulus->equals($components['modulus'])) {
$this->modulus = $components['modulus'];
$this->exponent = $this->publicExponent = $components['publicExponent'];
return true;
}
$this->publicExponent = $components['publicExponent'];
return true;
}
/**
* Returns the server public host key.
*
* Caching this the first time you connect to a server and checking the result on subsequent connections
* is recommended. Returns false if the server signature is not signed correctly with the public host key.
*
* @return Mixed
* @access public
*/
function getServerPublicHostKey()
{
if (!($this->bitmap & NET_SSH2_MASK_CONSTRUCTOR)) {
$this->bitmap |= NET_SSH2_MASK_CONSTRUCTOR;
if (!$this->_connect()) {
return false;
}
}
$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':
$zero = new Math_BigInteger();
$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');
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);
switch (true) {
case $r->equals($zero):
case $r->compare($q) >= 0:
case $s->equals($zero):
case $s->compare($q) >= 0:
user_error('Invalid signature');
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');
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')) {
include_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');
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');
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');
return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
}
break;
default:
user_error('Unsupported signature format');
return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
}
return $this->signature_format . ' ' . base64_encode($this->server_public_host_key);
}
/**
* Defines the public key
*
* Some private key formats define the public exponent and some don't. Those that don't define it are problematic when
* used in certain contexts. For example, in SSH-2, RSA authentication works by sending the public key along with a
* message signed by the private key to the server. The SSH-2 server looks the public key up in an index of public keys
* and if it's present then proceeds to verify the signature. Problem is, if your private key doesn't include the public
* exponent this won't work unless you manually add the public exponent.
*
* Do note that when a new key is loaded the index will be cleared.
*
* Returns true on success, false on failure
*
* @see getPublicKey()
* @access public
* @param String $key
* @param Integer $type optional
* @return Boolean
*/
function setPublicKey($key, $type = CRYPT_RSA_PUBLIC_FORMAT_PKCS1)
{
$components = $this->_parseKey($key, $type);
if (empty($this->modulus) || !$this->modulus->equals($components['modulus'])) {
return false;
}
$this->publicExponent = $components['publicExponent'];
}
/**
* Defines the public key
*
* Some private key formats define the public exponent and some don't. Those that don't define it are problematic when
* used in certain contexts. For example, in SSH-2, RSA authentication works by sending the public key along with a
* message signed by the private key to the server. The SSH-2 server looks the public key up in an index of public keys
* and if it's present then proceeds to verify the signature. Problem is, if your private key doesn't include the public
* exponent this won't work unless you manually add the public exponent.
*
* Do note that when a new key is loaded the index will be cleared.
*
* Returns true on success, false on failure
*
* @see getPublicKey()
* @access public
* @param String $key
* @param Integer $type optional
* @return Boolean
*/
function setPublicKey($key, $type = CRYPT_RSA_PUBLIC_FORMAT_PKCS1)
{
$components = $this->_parseKey($key, $type);
if (empty($this->modulus) || !$this->modulus->equals($components['modulus'])) {
user_error('Trying to load a public key? Use loadKey() instead. It\'s called loadKey() and not loadPrivateKey() for a reason.', E_USER_NOTICE);
return false;
}
$this->publicExponent = $components['publicExponent'];
return true;
}
/**
* Defines the public key
*
* Some private key formats define the public exponent and some don't. Those that don't define it are problematic when
* used in certain contexts. For example, in SSH-2, RSA authentication works by sending the public key along with a
* message signed by the private key to the server. The SSH-2 server looks the public key up in an index of public keys
* and if it's present then proceeds to verify the signature. Problem is, if your private key doesn't include the public
* exponent this won't work unless you manually add the public exponent.
*
* Do note that when a new key is loaded the index will be cleared.
*
* Returns true on success, false on failure
*
* @see getPublicKey()
* @access public
* @param String $key optional
* @param Integer $type optional
* @return Boolean
*/
function setPublicKey($key = false, $type = false)
{
if ($key === false && !empty($this->modulus)) {
$this->publicExponent = $this->exponent;
return true;
}
if ($type === false) {
$types = array(CRYPT_RSA_PUBLIC_FORMAT_RAW, CRYPT_RSA_PUBLIC_FORMAT_PKCS1, CRYPT_RSA_PUBLIC_FORMAT_XML, CRYPT_RSA_PUBLIC_FORMAT_OPENSSH);
foreach ($types as $type) {
try {
$components = $this->_parseKey($key, $type);
break;
} catch (FormatNotSupportedException $e) {
}
}
if (!isset($components)) {
throw new FormatNotSupportedException('Unable to find matching format');
}
} else {
$components = $this->_parseKey($key, $type);
}
if (empty($this->modulus) || !$this->modulus->equals($components['modulus'])) {
$this->modulus = $components['modulus'];
$this->exponent = $this->publicExponent = $components['publicExponent'];
return true;
}
$this->publicExponent = $components['publicExponent'];
return true;
}
/**
*
* @param unknown $text string
* @param unknown $unblindf string: hex encoded bigInt
* @param unknown $blindedHash string: hex encoded bigInt
*/
function verifyBlindedHash($text, $unblindf, $blindedHash)
{
$hashByMe = hash('sha256', $text);
$hashByMeBigInt = new Math_BigInteger($hashByMe, 16);
$blindedHashBigInt = new Math_BigInteger($blindedHash, 16);
$signedblindedHash = $this->myPrivateKey['privRsa']->_rsasp1($blindedHashBigInt);
$unblindf = new Math_BigInteger($unblindf, 16);
$unblindedSignedHash = $this->myPrivateKey['privRsa']->rsaUnblind($signedblindedHash, $unblindf);
$verifyHash = $this->myPrivateKey['pubRsa']->_rsasp1($unblindedSignedHash);
$hashOk = $hashByMeBigInt->equals($verifyHash);
if ($hashOk !== true) {
WrongRequestException::throwException(1002, "Error: blinded hash verification failed", "expected hash: {$hashByMe}, got unblinded hash: {$verifyHash}, blinded Hash {$blindedHash}, unblinding factor {$unblindf}");
}
return $hashOk;
}
