proc_open 交互

2021-12-23 00:00:00 ssh pipe php proc-open

这是我想要实现的目标:打开一个 shell(korn 或 bash，无所谓)，从那个 shell，我想打开一个 ssh 连接(ssh user@host).在某些时候可能会发生这种情况，我会被提示输入密码，或者我可能会被问到是否确定要连接(有问题的密钥).

Here's what I'm trying to achieve: open a shell (korn or bash, doesn't matter), from that shell, I want to open a ssh connection (ssh user@host). At some point it is likely to happen I will be prompted for either a password or I might be asked whether or not I'm sure I want to connect (offending keys).

在有人问之前:是的，我知道有一个用于 ssh2 exec 调用的插件，但是我正在使用的服务器不支持它，并且不太可能这样做.

Before anyone asks: yes, I am aware there is a plugin for ssh2 exec calls, but the servers I'm working on don't support it, and are unlikely to do so.

这是我迄今为止尝试过的:

Here's what I've tried so far: 

$desc = array(array('pipe','r'),array('pipe','w'));//used in all example code
$p = proc_open('ssh user@host',$desc,$pipes);
if(!is_resource($p)){ die('@!#$%');}//will omit this line from now on
sleep(1);//omitting this,too but it's there every time I need it

然后我尝试读取控制台输出 (stream_get_contents($pipes[1])) 以查看我接下来必须传递的内容(密码，是或返回 'connection failed: '.stream_get_contents($pipes[1]) 和 proc_close $p.

Then I tried to read console output (stream_get_contents($pipes[1])) to see what I have to pass next (either password, yes or return 'connection failed: '.stream_get_contents($pipes[1]) and proc_close $p.

这给了我以下错误:

伪终端不会被分配，因为 stdin 不是终端.

Pseudo-terminal will not be allocated because stdin is not a terminal.

所以，我虽然在 php:// io-stream 上下文中调用了 ssh，但似乎是上述错误的合理解释.

So, I though ssh was called in the php:// io-stream context, seems a plausible explanation of the above error.

下一步:我虽然关于 我的第一个 SO 问题 并决定它可能是一个最好先打开 bash/ksh shell:

Next: I though about my first SO question and decided it might be a good idea to open a bash/ksh shell first:

$p = proc_open('bash',$desc,$pipes);

从那里开始，但我收到了完全相同的错误消息，只是这一次，脚本停止运行，但 ssh 确实运行了.所以我充满希望，然后觉得自己很愚蠢，最终绝望了:

And take it from there, but I got the exact same error message, only this time, the script stopped running but ssh did run. So I got hopeful, then felt stupid and, eventually, desperate:

$p=proc_open('bash && ssh user@host',$desc,$pipes);

等待几秒钟后，我收到以下错误:

After a few seconds wait, I got the following error:

PHP 致命错误:允许的内存大小为 134217728 字节已用完(尝试分配 133693440 字节)

PHP Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 133693440 bytes)

即使在我最后一次绝望的尝试中，调用堆栈也会不断地调用 stream_get_contents 行:

The Call Stack keeps bringing up the stream_get_contents line, even in my last desperate attempt:

#!/path/to/bin/php -n
<?php
    $p = proc_open('bash && ssh user@host',array(array('pipe','r'),array('pipe','w')),$ps);
    if (!is_resource($p))
    {
        die('FFS');
    }
    usleep(10);
    fwrite($ps[0],'yes'."
");
    fflush($ps[0]);
    usleep(20);
    fwrite($ps[0],'password'."
");
    fflush($ps[0]);
    usleep(20);
    fwrite($ps[0],'whoami'."
");
    fflush($ps[0]);
    usleep(2);
    $msg = stream_get_contents($ps[1]);
    fwrite($ps[0],'exit'."
");
    fclose($ps[0]);
    fclose($ps[1]);
    proc_close($p);
?>

我知道，它很乱，有很多fflush 和冗余，但重点是:我知道这个连接会首先提示我输入有问题的密钥，然后询问密码.我的猜测是 $pipes[1] 中的流包含 ssh 连接，因此它的内容很大.那么我需要的是管道内的管道......这甚至可能吗?我一定是遗漏了什么，如果这不可能的话，管子有什么用……我的猜测是 proc_open 命令开始是错误的，(错误:管道损坏).但我真的看不到第一个错误的任何其他方式......有什么想法吗?或者，如果上述咆哮根本不清楚(可能不是)，请跟进问题.

I know, its a mess, a lot of fflush and redundancy, but the point is: I know this connection will first prompt me for offending keys, and then ask a password. My guess is the stream in $pipes[1] holds the ssh connection, hence it's content is huge. what I need then, is a pipe inside a pipe... is this even possible? I must be missing something, what good is a pipe if this isn't possible... My guess is the proc_open command is wrong to begin with, (error: Broken pipe). But I really can't see any other way around the first error... any thoughts? Or follow up questions if the above rant isn't at all clear (which it probably isn't).

推荐答案

在有人问之前:是的，我知道有一个用于 ssh2 exec 的插件调用，但我正在使用的服务器不支持它，并且不太可能这样做.

Before anyone asks: yes, I am aware there is a plugin for ssh2 exec calls, but the servers I'm working on don't support it, and are unlikely to do so.

实际上有两个.PECL 模块，这是大多数服务器都没有安装的 PITA 和 phpseclib，一个纯 PHP SSH2 实现.其使用示例:

There are actually two. The PECL module, which is a PITA that most servers don't have installed anyway and phpseclib, a pure PHP SSH2 implementation. An example of its use:

<?php
include('Net/SSH2.php');

$ssh = new Net_SSH2('www.domain.tld');
if (!$ssh->login('username', 'password')) {
    exit('Login Failed');
}

echo $ssh->exec('pwd');
echo $ssh->exec('ls -la');
?>

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