PHP ssh2://

The ssh2:// wrapper in PHP provides secure access to remote resources using the libssh2 library. It enables shell access, remote execution, tunneling, file transfer, and SCP operations through cryptographic transport.

Installation Required: The SSH2 extension must be installed from PECL as it's not enabled by default in PHP.

Install using: pecl install ssh2

Available SSH2 Wrappers

PHP provides several SSH2 wrappers for different operations −

ssh2.shell://user:pass@example.com:22/xterm
ssh2.exec://user:pass@example.com:22/usr/local/bin/somecmd
ssh2.tunnel://user:pass@example.com:22/192.168.0.1:14
ssh2.sftp://user:pass@example.com:22/path/to/filename
ssh2.scp://user:pass@example.com:22/path/to/filename

Basic Example

Here's how to read a remote file using SSH2 SFTP wrapper −

<?php
// Create context with SSH2 options
$context = stream_context_create([
    'ssh2' => [
        'username' => 'myuser',
        'password' => 'mypassword'
    ]
]);

// Read remote file
$contents = file_get_contents('ssh2.sftp://example.com/path/to/file.txt', false, $context);
echo $contents;
?>

Context Options

Key-Based Authentication

For enhanced security, use SSH keys instead of passwords −

<?php
$context = stream_context_create([
    'ssh2' => [
        'username' => 'myuser',
        'pubkey_file' => '/path/to/public.key',
        'privkey_file' => '/path/to/private.key'
    ]
]);

$handle = fopen('ssh2.sftp://example.com/remote/file.txt', 'r', false, $context);
?>

Conclusion

SSH2 wrappers provide a convenient way to access remote resources securely in PHP. They support various authentication methods and can be used with standard PHP file functions for seamless remote operations.