如何在Laravel 5.5中动态设置SSH密钥？

Great question! Storing SSH keys in your database and using them dynamically without writing to disk is totally feasible—here are a couple of solid approaches to implement this in Laravel:

1. Use phpseclib (Recommended: No File I/O Required) #

phpseclib is a pure-PHP SSH library that lets you pass in private key content directly as a string, no file path needed. This is perfect for your use case since it skips disk operations entirely.

First, install the package:

composer require phpseclib/phpseclib

Then, create a method or service class to fetch your server details and key from the database, then establish the connection:

use phpseclib3\Net\SSH2;
use phpseclib3\Crypt\RSA;
use App\Models\Server; // Adjust this to your actual Server model
use Exception;

// Fetch server and its stored private key from the database
$server = Server::findOrFail($targetServerId);
$privateKeyString = $server->ssh_private_key; // Make sure this includes the full key (-----BEGIN RSA PRIVATE KEY----- and footer)

// Load the key from the string
$privateKey = RSA::load($privateKeyString);

// Initialize SSH connection
$ssh = new SSH2($server->host);
if (!$ssh->login($server->username, $privateKey)) {
    throw new Exception('Failed to authenticate with SSH key');
}

// Run your commands
$commandOutput = $ssh->exec('ls -la');
echo $commandOutput;

This approach has minimal overhead since it works directly with the key string from your database—no file writes, no disk delays.

2. Extend Laravel's Remote Component (With Memory-Based Temp Files) #

If you prefer using Laravel's familiar SSH facade (note: the Remote component was moved out of core in Laravel 5.1, so you'll need the laravelcollective/remote package), you can use a memory-based temporary file to avoid disk I/O.

First, install the package:

composer require laravelcollective/remote

Then, implement the dynamic connection:

use Illuminate\Support\Facades\Config;
use Collective\Remote\RemoteFacade as SSH;
use App\Models\Server;

// Fetch server data from DB
$server = Server::findOrFail($targetServerId);
$privateKeyString = $server->ssh_private_key;

// Create a temp file in RAM (uses /dev/shm on Linux, which is a RAM filesystem)
$tempKeyPath = '/dev/shm/ssh_key_' . uniqid();
file_put_contents($tempKeyPath, $privateKeyString);
chmod($tempKeyPath, 0600); // SSH requires private keys to have strict 600 permissions

// Dynamically add a new SSH connection config
Config::set('remote.connections.' . $server->id, [
    'host' => $server->host,
    'username' => $server->username,
    'key' => $tempKeyPath,
]);

// Execute commands using the dynamic connection
SSH::connection($server->id)->run(['ls -la'], function($line) {
    echo $line . PHP_EOL;
});

// Clean up the temp file immediately after use
unlink($tempKeyPath);

The /dev/shm path ensures the temp file lives in RAM, so writes/reads are nearly instant with no disk overhead. For Windows environments, you can use sys_get_temp_dir() instead, though it won't be RAM-based—still better than persistent disk files.

Critical Extra Tip #

Always encrypt your private keys in the database! Never store plain-text keys. Use Laravel's built-in encryption to secure them:

• Store: Crypt::encryptString($rawPrivateKey)
• Retrieve: Crypt::decryptString($encryptedKeyFromDb)

This adds a critical layer of security if your database ever gets compromised.

内容的提问来源于stack exchange，提问作者Adarsh Sojitra