Merge pull request #1904 from terrafrost/3.0-openchannel

(3.0 branch) SSH/SFTP: create new openChannel() method to eliminate dupe code
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terrafrost 2023-05-10 04:38:51 -05:00 committed by GitHub
commit b25206e92b
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4 changed files with 131 additions and 101 deletions

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@ -545,22 +545,7 @@ class SFTP extends SSH2
*/
private function partial_init_sftp_connection()
{
$this->window_size_server_to_client[self::CHANNEL] = $this->window_size;
$packet = Strings::packSSH2(
'CsN3',
NET_SSH2_MSG_CHANNEL_OPEN,
'session',
self::CHANNEL,
$this->window_size,
0x4000
);
$this->send_binary_packet($packet);
$this->channel_status[self::CHANNEL] = NET_SSH2_MSG_CHANNEL_OPEN;
$response = $this->get_channel_packet(self::CHANNEL, true);
$response = $this->openChannel(self::CHANNEL, true);
if ($response === true && $this->isTimeout()) {
return false;
}

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@ -1087,6 +1087,21 @@ class SSH2
*/
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;
/**
* Default Constructor.
*
@ -1384,6 +1399,18 @@ class SSH2
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, $this->identifier . "\r\n");
}
@ -2725,32 +2752,11 @@ class SSH2
return false;
}
if ($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.');
}
//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.');
//}
// 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[self::CHANNEL_EXEC] = $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',
self::CHANNEL_EXEC,
$this->window_size_server_to_client[self::CHANNEL_EXEC],
$packet_size
);
$this->send_binary_packet($packet);
$this->channel_status[self::CHANNEL_EXEC] = NET_SSH2_MSG_CHANNEL_OPEN;
$this->get_channel_packet(self::CHANNEL_EXEC);
$this->openChannel(self::CHANNEL_EXEC);
if ($this->request_pty === true) {
$terminal_modes = pack('C', NET_SSH2_TTY_OP_END);
@ -2830,6 +2836,60 @@ class SSH2
}
}
/**
* 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, $skip_extended);
}
/**
* Creates an interactive shell
*
@ -2846,31 +2906,11 @@ class SSH2
*/
public function openShell()
{
if ($this->isShellOpen()) {
return false;
}
if (!$this->isAuthenticated()) {
throw new InsufficientSetupException('Operation disallowed prior to login()');
}
$this->window_size_server_to_client[self::CHANNEL_SHELL] = $this->window_size;
$packet_size = 0x4000;
$packet = Strings::packSSH2(
'CsN3',
NET_SSH2_MSG_CHANNEL_OPEN,
'session',
self::CHANNEL_SHELL,
$this->window_size_server_to_client[self::CHANNEL_SHELL],
$packet_size
);
$this->send_binary_packet($packet);
$this->channel_status[self::CHANNEL_SHELL] = NET_SSH2_MSG_CHANNEL_OPEN;
$this->get_channel_packet(self::CHANNEL_SHELL);
$this->openChannel(self::CHANNEL_SHELL);
$terminal_modes = pack('C', NET_SSH2_TTY_OP_END);
$packet = Strings::packSSH2(
@ -3023,6 +3063,10 @@ class SSH2
*/
public function read($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;
@ -3030,7 +3074,7 @@ class SSH2
$channel = $this->get_interactive_channel();
}
if (!$this->isInteractiveChannelOpen($channel)) {
if (!$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 (!$this->openShell()) {
@ -3080,11 +3124,15 @@ class SSH2
*/
public function write($cmd, $channel = null)
{
if (!$this->isAuthenticated()) {
throw new InsufficientSetupException('Operation disallowed prior to login()');
}
if ($channel === null) {
$channel = $this->get_interactive_channel();
}
if (!$this->isInteractiveChannelOpen($channel)) {
if (!$this->is_channel_status_data($channel)) {
if ($channel != self::CHANNEL_SHELL) {
throw new InsufficientSetupException('Data is not available on channel');
} elseif (!$this->openShell()) {
@ -3110,22 +3158,7 @@ class SSH2
*/
public function startSubsystem($subsystem)
{
$this->window_size_server_to_client[self::CHANNEL_SUBSYSTEM] = $this->window_size;
$packet = Strings::packSSH2(
'CsN3',
NET_SSH2_MSG_CHANNEL_OPEN,
'session',
self::CHANNEL_SUBSYSTEM,
$this->window_size,
0x4000
);
$this->send_binary_packet($packet);
$this->channel_status[self::CHANNEL_SUBSYSTEM] = NET_SSH2_MSG_CHANNEL_OPEN;
$this->get_channel_packet(self::CHANNEL_SUBSYSTEM);
$this->openChannel(self::CHANNEL_SUBSYSTEM);
$packet = Strings::packSSH2(
'CNsCs',
@ -3303,23 +3336,8 @@ class SSH2
return false;
}
$this->window_size_server_to_client[self::CHANNEL_KEEP_ALIVE] = $this->window_size;
$packet_size = 0x4000;
$packet = Strings::packSSH2(
'CsN3',
NET_SSH2_MSG_CHANNEL_OPEN,
'session',
self::CHANNEL_KEEP_ALIVE,
$this->window_size_server_to_client[self::CHANNEL_KEEP_ALIVE],
$packet_size
);
try {
$this->send_binary_packet($packet);
$this->channel_status[self::CHANNEL_KEEP_ALIVE] = NET_SSH2_MSG_CHANNEL_OPEN;
$response = $this->get_channel_packet(self::CHANNEL_KEEP_ALIVE);
$this->openChannel(self::CHANNEL_KEEP_ALIVE);
} catch (\RuntimeException $e) {
return $this->reconnect();
}
@ -4111,6 +4129,8 @@ class SSH2
}
$this->channel_status[$channel] = NET_SSH2_MSG_CHANNEL_CLOSE;
$this->channelCount--;
if ($client_channel == $channel) {
return true;
}
@ -4445,6 +4465,7 @@ class SSH2
}
$this->channel_status[$client_channel] = NET_SSH2_MSG_CHANNEL_CLOSE;
$this->channelCount--;
$this->curTimeout = 5;
@ -4916,6 +4937,14 @@ class SSH2
];
}
/**
* Force multiple channels (even if phpseclib has decided to disable them)
*/
public function forceMultipleChannels()
{
$this->errorOnMultipleChannels = false;
}
/**
* Allows you to set the terminal
*

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@ -416,7 +416,7 @@ class SSH2Test extends PhpseclibFunctionalTestCase
public function testMultipleExecPty()
{
$this->expectException(\RuntimeException::class);
$this->expectExceptionMessage('If you want to run multiple exec()\'s you will need to disable (and re-enable if appropriate) a PTY for each one.');
$this->expectExceptionMessage('Please close the channel (1) before trying to open it again');
$ssh = $this->getSSH2Login();
@ -542,4 +542,21 @@ class SSH2Test extends PhpseclibFunctionalTestCase
'Failed asserting that exec channel identifier is maintained as last opened channel.'
);
}
public function testReadingOfClosedChannel()
{
$ssh = $this->getSSH2Login();
$this->assertSame(0, $ssh->getOpenChannelCount());
$ssh->enablePTY();
$ssh->exec('ping -c 3 127.0.0.1; exit');
$ssh->write("ping 127.0.0.2\n", SSH2::CHANNEL_SHELL);
$ssh->setTimeout(3);
$output = $ssh->read('', SSH2::READ_SIMPLE, SSH2::CHANNEL_SHELL);
$this->assertStringContainsString('PING 127.0.0.2', $output);
$output = $ssh->read('', SSH2::READ_SIMPLE, SSH2::CHANNEL_EXEC);
$this->assertStringContainsString('PING 127.0.0.1', $output);
$this->assertSame(1, $ssh->getOpenChannelCount());
$ssh->reset(SSH2::CHANNEL_SHELL);
$this->assertSame(0, $ssh->getOpenChannelCount());
}
}

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@ -202,12 +202,11 @@ class SSH2UnitTest extends PhpseclibTestCase
{
$ssh = $this->getMockBuilder(SSH2::class)
->disableOriginalConstructor()
->setMethods(['__destruct', 'isShellOpen'])
->setMethods(['__destruct'])
->getMock();
$ssh->expects($this->once())
->method('isShellOpen')
->willReturn(true);
$this->expectException(InsufficientSetupException::class);
$this->expectExceptionMessage('Operation disallowed prior to login()');
$this->assertFalse($ssh->openShell());
}