danog/tgseclib
1
0
Fork 0
mirror of https://github.com/danog/tgseclib.git synced 2024-11-27 04:34:45 +01:00
Code Issues Projects Releases Wiki Activity

Add support for RFC 4419: diffie-hellman-group-exchange-sha{1,256}

Browse Source
This commit is contained in:
Andreas Fischer 2015-06-25 00:50:00 +02:00
parent 92a7f74d8a
commit abeda5237f
1 changed files with 126 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

113
phpseclib/Net/SSH2.php
View File

@ -206,6 +206,33 @@ class Net_SSH2
*/
var $kex_algorithms = false;
/**
* Minimum Diffie-Hellman Group Bit Size in RFC 4419 Key Exchange Methods
*
* @see Net_SSH2::_key_exchange()
* @var Integer
* @access private
*/
var $kex_dh_group_size_min = 1536;
/**
* Preferred Diffie-Hellman Group Bit Size in RFC 4419 Key Exchange Methods
*
* @see Net_SSH2::_key_exchange()
* @var Integer
* @access private
*/
var $kex_dh_group_size_preferred = 2048;
/**
* Maximum Diffie-Hellman Group Bit Size in RFC 4419 Key Exchange Methods
*
* @see Net_SSH2::_key_exchange()
* @var Integer
* @access private
*/
var $kex_dh_group_size_max = 4096;
/**
* Server Host Key Algorithms
*
@ -942,7 +969,13 @@ class Net_SSH2
array(60 => 'NET_SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ'),
array(60 => 'NET_SSH2_MSG_USERAUTH_PK_OK'),
array(60 => 'NET_SSH2_MSG_USERAUTH_INFO_REQUEST',
61 => 'NET_SSH2_MSG_USERAUTH_INFO_RESPONSE')
61 => 'NET_SSH2_MSG_USERAUTH_INFO_RESPONSE'),
// RFC 4419 - diffie-hellman-group-exchange-sha{1,256}
array(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')
);
$this->host = $host;
@ -1123,7 +1156,9 @@ class Net_SSH2
{
static $kex_algorithms = array(
'diffie-hellman-group1-sha1', // REQUIRED
'diffie-hellman-group14-sha1' // REQUIRED
'diffie-hellman-group14-sha1', // REQUIRED
'diffie-hellman-group-exchange-sha1', // RFC 4419
'diffie-hellman-group-exchange-sha256', // RFC 4419
);
static $server_host_key_algorithms = array(
@ -1403,6 +1438,48 @@ class Net_SSH2
return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
}
if (strpos($kex_algorithms[$i], '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,
$dh_group_sizes_packed
);
if (!$this->_send_binary_packet($packet)) {
return false;
}
$response = $this->_get_binary_packet();
if ($response === false) {
user_error('Connection closed by server');
return false;
}
extract(unpack('Ctype', $this->_string_shift($response, 1)));
if ($type != NET_SSH2_MSG_KEXDH_GEX_GROUP) {
user_error('Expected SSH_MSG_KEX_DH_GEX_GROUP');
return false;
}
extract(unpack('NprimeLength', $this->_string_shift($response, 4)));
$primeBytes = $this->_string_shift($response, $primeLength);
$prime = new Math_BigInteger($primeBytes, -256);
extract(unpack('NgLength', $this->_string_shift($response, 4)));
$gBytes = $this->_string_shift($response, $gLength);
$g = new Math_BigInteger($gBytes, -256);
$exchange_hash_rfc4419 = pack('a*Na*Na*',
$dh_group_sizes_packed,
$primeLength, $primeBytes,
$gLength, $gBytes
);
$clientKexInitMessage = NET_SSH2_MSG_KEXDH_GEX_INIT;
$serverKexReplyMessage = NET_SSH2_MSG_KEXDH_GEX_REPLY;
} else {
switch ($kex_algorithms[$i]) {
// see http://tools.ietf.org/html/rfc2409#section-6.2 and
// http://tools.ietf.org/html/rfc2412, appendex E
@ -1424,13 +1501,22 @@ class Net_SSH2
'3995497CEA956AE515D2261898FA051015728E5A8AACAA68FFFFFFFFFFFFFFFF';
break;
}
// For both diffie-hellman-group1-sha1 and diffie-hellman-group14-sha1
// the generator field element is 2 (decimal) and the hash function is sha1.
$g = new Math_BigInteger(2);
$prime = new Math_BigInteger($prime, 16);
$exchange_hash_rfc4419 = '';
$clientKexInitMessage = NET_SSH2_MSG_KEXDH_INIT;
$serverKexReplyMessage = NET_SSH2_MSG_KEXDH_REPLY;
}
switch ($kex_algorithms[$i]) {
case 'diffie-hellman-group-exchange-sha256':
$kexHash = new Crypt_Hash('sha256');
break;
default:
$kexHash = new Crypt_Hash('sha1');
//$q = $p->bitwise_rightShift(1);
}
/* To increase the speed of the key exchange, both client and server may
reduce the size of their private exponents. It should be at least
@ -1448,7 +1534,7 @@ class Net_SSH2
$e = $g->modPow($x, $prime);
$eBytes = $e->toBytes(true);
$data = pack('CNa*', NET_SSH2_MSG_KEXDH_INIT, strlen($eBytes), $eBytes);
$data = pack('CNa*', $clientKexInitMessage, strlen($eBytes), $eBytes);
if (!$this->_send_binary_packet($data)) {
user_error('Connection closed by server');
@ -1462,7 +1548,7 @@ class Net_SSH2
}
extract(unpack('Ctype', $this->_string_shift($response, 1)));
if ($type != NET_SSH2_MSG_KEXDH_REPLY) {
if ($type != $serverKexReplyMessage) {
user_error('Expected SSH_MSG_KEXDH_REPLY');
return false;
}
@ -1486,11 +1572,16 @@ class Net_SSH2
$key = $f->modPow($x, $prime);
$keyBytes = $key->toBytes(true);
$this->exchange_hash = pack('Na*Na*Na*Na*Na*Na*Na*Na*',
strlen($this->identifier), $this->identifier, strlen($this->server_identifier), $this->server_identifier,
strlen($kexinit_payload_client), $kexinit_payload_client, strlen($kexinit_payload_server),
$kexinit_payload_server, strlen($this->server_public_host_key), $this->server_public_host_key, strlen($eBytes),
$eBytes, strlen($fBytes), $fBytes, strlen($keyBytes), $keyBytes
$this->exchange_hash = pack('Na*Na*Na*Na*Na*a*Na*Na*Na*',
strlen($this->identifier), $this->identifier,
strlen($this->server_identifier), $this->server_identifier,
strlen($kexinit_payload_client), $kexinit_payload_client,
strlen($kexinit_payload_server), $kexinit_payload_server,
strlen($this->server_public_host_key), $this->server_public_host_key,
$exchange_hash_rfc4419,
strlen($eBytes), $eBytes,
strlen($fBytes), $fBytes,
strlen($keyBytes), $keyBytes
);
$this->exchange_hash = $kexHash->hash($this->exchange_hash);