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SSHi2: stop using dynamic properties in SymmetricKey

This commit is contained in:
terrafrost 2022-01-30 01:36:02 -06:00
parent 0a9fc99dc8
commit 215fd61d12
2 changed files with 52 additions and 23 deletions
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7
phpseclib/Crypt/Common/SymmetricKey.php
View File

@ -213,13 +213,6 @@ abstract class SymmetricKey
self::ENGINE_OPENSSL_GCM => 'OpenSSL (GCM)'
];
/** @var string|null */
public $fixed;
/** @var string|null */
public $invocation_counter;
/** @var string|null */
public $name;
/**
* The Encryption Mode
*

68
phpseclib/Net/SSH2.php
View File

@ -410,6 +410,24 @@ class SSH2
*/
private $decrypt = false;
/**
* Decryption Algorithm Name
*
* @var string|null
* @access private
*/
private $decryptName;
/**
* Decryption Invocation Counter
*
* Used by GCM
*
* @var string|null
* @access private
*/
private $decryptInvocationCounter;
/**
* Server to Client Length Encryption Object
*
@ -428,6 +446,24 @@ class SSH2
*/
private $encrypt = false;
/**
* Encryption Algorithm Name
*
* @var string|null
* @access private
*/
private $encryptName;
/**
* Encryption Invocation Counter
*
* Used by GCM
*
* @var string|null
* @access private
*/
private $encryptInvocationCounter;
/**
* Client to Server Length Encryption Object
*
@ -1860,7 +1896,7 @@ class SSH2
case 'aes256-gcm@openssh.com':
$nonce = $kexHash->hash($keyBytes . $this->exchange_hash . 'A' . $this->session_id);
$this->encrypt->fixed = substr($nonce, 0, 4);
$this->encrypt->invocation_counter = substr($nonce, 4, 8);
$this->encryptInvocationCounter = substr($nonce, 4, 8);
case 'chacha20-poly1305@openssh.com':
break;
default:
@ -1878,7 +1914,7 @@ class SSH2
$this->lengthEncrypt->setKey(substr($key, 32, 32));
}
$this->encrypt->setKey(substr($key, 0, $encryptKeyLength));
$this->encrypt->name = $encrypt;
$this->encryptName = $encrypt;
}
$this->decrypt = self::encryption_algorithm_to_crypt_instance($decrypt);
@ -1905,7 +1941,7 @@ class SSH2
// see https://tools.ietf.org/html/rfc5647#section-7.1
$nonce = $kexHash->hash($keyBytes . $this->exchange_hash . 'B' . $this->session_id);
$this->decrypt->fixed = substr($nonce, 0, 4);
$this->decrypt->invocation_counter = substr($nonce, 4, 8);
$this->decryptInvocationCounter = substr($nonce, 4, 8);
case 'chacha20-poly1305@openssh.com':
break;
default:
@ -1923,7 +1959,7 @@ class SSH2
$this->lengthDecrypt->setKey(substr($key, 32, 32));
}
$this->decrypt->setKey(substr($key, 0, $decryptKeyLength));
$this->decrypt->name = $decrypt;
$this->decryptName = $decrypt;
}
/* The "arcfour128" algorithm is the RC4 cipher, as described in
@ -3367,14 +3403,14 @@ class SSH2
}
if ($this->decrypt) {
switch ($this->decrypt->name) {
switch ($this->decryptName) {
case 'aes128-gcm@openssh.com':
case 'aes256-gcm@openssh.com':
$this->decrypt->setNonce(
$this->decrypt->fixed .
$this->decrypt->invocation_counter
$this->decryptInvocationCounter
);
Strings::increment_str($this->decrypt->invocation_counter);
Strings::increment_str($this->decryptInvocationCounter);
$this->decrypt->setAAD($temp = Strings::shift($raw, 4));
extract(unpack('Npacket_length', $temp));
/**
@ -3552,9 +3588,9 @@ class SSH2
$adjustLength = false;
if ($this->decrypt) {
switch (true) {
case $this->decrypt->name == 'aes128-gcm@openssh.com':
case $this->decrypt->name == 'aes256-gcm@openssh.com':
case $this->decrypt->name == 'chacha20-poly1305@openssh.com':
case $this->decryptName == 'aes128-gcm@openssh.com':
case $this->decryptName == 'aes256-gcm@openssh.com':
case $this->decryptName == 'chacha20-poly1305@openssh.com':
case $this->hmac_check instanceof Hash && $this->hmac_check->etm:
$remaining_length+= $this->decrypt_block_size - 4;
$adjustLength = true;
@ -3566,7 +3602,7 @@ class SSH2
// PuTTY uses 0x9000 as the actual max packet size and so to shall we
// don't do this when GCM mode is used since GCM mode doesn't encrypt the length
if ($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 ? $this->decrypt->name : '') && !($this->bitmap & SSH2::MASK_LOGIN)) {
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;
$this->reset_connection(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
return false;
@ -4125,14 +4161,14 @@ class SSH2
}
if ($this->encrypt) {
switch ($this->encrypt->name) {
switch ($this->encryptName) {
case 'aes128-gcm@openssh.com':
case 'aes256-gcm@openssh.com':
$this->encrypt->setNonce(
$this->encrypt->fixed .
$this->encrypt->invocation_counter
$this->encryptInvocationCounter
);
Strings::increment_str($this->encrypt->invocation_counter);
Strings::increment_str($this->encryptInvocationCounter);
$this->encrypt->setAAD($temp = ($packet & "\xFF\xFF\xFF\xFF"));
$packet = $temp . $this->encrypt->encrypt(substr($packet, 4));
break;
@ -4798,12 +4834,12 @@ class SSH2
'kex' => $this->kex_algorithm,
'hostkey' => $this->signature_format,
'client_to_server' => [
'crypt' => $this->encrypt->name,
'crypt' => $this->encryptName,
'mac' => $this->hmac_create->name,
'comp' => $compression_map[$this->compress],
],
'server_to_client' => [
'crypt' => $this->decrypt->name,
'crypt' => $this->decryptName,
'mac' => $this->hmac_check->name,
'comp' => $compression_map[$this->decompress],
]