dartssh2 2.5.0
dartssh2: ^2.5.0 copied to clipboard
SSH and SFTP client written in pure Dart, aiming to be feature-rich as well as easy to use.
DartSSH 2
SSH and SFTP client written in pure Dart, aiming to be feature-rich as well as easy to use.
dartssh2 is now a complete rewrite of dartssh.
โจ Features #
- Pure Dart: Working with both Dart VM and Flutter.
- SSH Session: Executing commands, spawning shells, setting environment variables, pseudo terminals, etc.
- Authentication: Supports password, private key and interactive authentication method.
- Forwarding: Supports local forwarding and remote forwarding.
- SFTP: Supports all operations defined in SFTPv3 protocol including upload, download, list, link, remove, rename, etc.
๐งช Try #
# Install the `dartssh` command.
dart pub global activate dartssh2
# Then use `dartssh` as regular `ssh` command.
dartssh user@example.com
# Example: execute a command on remote host.
dartssh user@example.com ls -al
# Example: connect to a non-standard port.
dartssh user@example.com:<port>
# Transfer files via SFTP.
dartsftp user@example.com
If the
dartssh
command can't be found after installation, you might need to set up your path.
๐ Quick start #
Connect to a remote host #
final client = SSHClient(
await SSHSocket.connect('localhost', 22),
username: '<username>',
onPasswordRequest: () => '<password>',
);
SSHSocket
is an interface and it's possible to implement your ownSSHSocket
if you want to use a different underlying transport rather than standard TCP socket. For example WebSocket or Unix domain socket.
Spawn a shell on remote host #
final shell = await client.shell();
stdout.addStream(shell.stdout); // listening for stdout
stderr.addStream(shell.stderr); // listening for stderr
stdin.cast<Uint8List>().listen(shell.write); // writing to stdin
await shell.done; // wait for shell to exit
client.close();
Execute a command on remote host #
final uptime = await client.run('uptime');
print(utf8.decode(uptime));
client.run()
is a convenience method that wrapsclient.execute()
for running non-interactive commands.
Start a process on remote host #
final session = await client.execute('cat > file.txt');
await session.stdin.addStream(File('local_file.txt').openRead().cast());
await session.stdin.close(); // Close the sink to send EOF to the remote process.
await session.done; // Wait for session to exit to ensure all data is flushed to the remote process.
print(session.exitCode); // You can get the exit code after the session is done
session.write()
is a shorthand forsession.stdin.add()
. It's recommended to usesession.stdin.addStream()
instead ofsession.write()
when you want to stream large amount of data to the remote process.
Killing a remote process by sending signal
session.kill(SSHSignal.KILL);
await session.done;
print('exitCode: ${session.exitCode}'); // -> exitCode: null
print('signal: ${session.exitSignal?.signalName}'); // -> signal: KILL
Processes killed by signals do not have an exit code, instead they have an exit signal property.
Forward connections on local port 8080 to the server #
final serverSocket = await ServerSocket.bind('localhost', 8080);
await for (final socket in serverSocket) {
final forward = await client.forwardLocal('httpbin.org', 80);
forward.stream.cast<List<int>>().pipe(socket);
socket.pipe(forward.sink);
}
Forward connections to port 2222 on the server to local port 22 #
final forward = await client.forwardRemote(port: 2222);
if (forward == null) {
print('Failed to forward remote port');
return;
}
await for (final connection in forward.connections) {
final socket = await Socket.connect('localhost', 22);
connection.stream.cast<List<int>>().pipe(socket);
socket.pipe(connection.sink);
}
Authenticate with public keys #
final client = SSHClient(
socket,
username: '<username>',
identities: [
// A single private key file may contain multiple keys.
...SSHKeyPair.fromPem(await File('path/to/id_rsa').readAsString())
],
);
Use encrypted PEM files #
// Test whether the private key is encrypted.
final encrypted = SSHKeyPair.isEncrypted(await File('path/to/id_rsa').readAsString());
print(encrypted);
// If the private key is encrypted, you need to provide the passphrase.
final keys = SSHKeyPair.fromPem('<pem text>', '<passphrase>');
print(keys);
Decrypt PEM file with compute
in Flutter
List<SSHKeyPair> decryptKeyPairs(List<String> args) {
return SSHKeyPair.fromPem(args[0], args[1]);
}
final keypairs = await compute(decryptKeyPairs, ['<pem text>', '<passphrase>']);
Get the version of SSH server #
await client.authenticated;
print(client.remoteVersion); // SSH-2.0-OpenSSH_7.4p1
SFTP #
List remote directory #
final sftp = await client.sftp();
final items = await sftp.listdir('/');
for (final item in items) {
print(item.longname);
}
Read remote file #
final sftp = await client.sftp();
final file = await sftp.open('/etc/passwd');
final content = await file.readBytes();
print(latin1.decode(content));
Write remote file #
final sftp = await client.sftp();
final file = await sftp.open('file.txt', mode: SftpFileOpenMode.write);
await file.writeBytes(utf8.encode('hello there!') as Uint8List);
Write at specific offset
final data = utf8.encode('world') as Uint8List
await file.writeBytes(data, offset: 6);
File upload #
final sftp = await client.sftp();
final file = await sftp.open('file.txt', mode: SftpFileOpenMode.create | SftpFileOpenMode.write);
await file.write(File('local_file.txt').openRead().cast());
Clear the remote file before opening it
final file = await sftp.open('file.txt',
mode: SftpFileOpenMode.create | SftpFileOpenMode.truncate | SftpFileOpenMode.write
);
Directory operations #
final sftp = await client.sftp();
await sftp.mkdir('/path/to/dir');
await sftp.rmdir('/path/to/dir');
Get/Set attributes from/to remote file/directory #
await sftp.stat('/path/to/file');
await sftp.setStat(
'/path/to/file',
SftpFileAttrs(mode: SftpFileMode(userRead: true)),
);
Create a link #
final sftp = await client.sftp();
sftp.link('/from', '/to');
๐ช Example #
SSH client: #
- example/example.dart
- example/execute.dart
- example/forward_local.dart
- example/forward_remote.dart
- example/pubkey.dart
- example/shell.dart
SFTP: #
๐ Supported algorithms #
Host key:
ssh-rsa
rsa-sha2-[256|512]
ecdsa-sha2-nistp[256|384|521]
ssh-ed25519
Key exchange:
curve25519-sha256
ecdh-sha2-nistp[256|384|521]
diffie-hellman-group-exchange-sha[1|256]
diffie-hellman-group14-sha[1|256]
diffie-hellman-group1-sha1
Cipher:
aes[128|192|256]-ctr
aes[128|192|256]-cbc
Integrity:
hmac-md5
hmac-sha1
hmac-sha2-[256|512]
โณ Roadmap #
- Fix broken tests
- Sound null safety
- Redesign API to allow starting multiple sessions.
- Full SFTP
- Server
References #
RFC 4250
The Secure Shell (SSH) Protocol Assigned NumbersRFC 4251
The Secure Shell (SSH) Protocol ArchitectureRFC 4252
The Secure Shell (SSH) Authentication ProtocolRFC 4253
The Secure Shell (SSH) Transport Layer ProtocolRFC 4254
The Secure Shell (SSH) Connection ProtocolRFC 4255
Using DNS to Securely Publish Secure Shell (SSH) Key FingerprintsRFC 4256
Generic Message Exchange Authentication for the Secure Shell Protocol (SSH)RFC 4419
Diffie-Hellman Group Exchange for the Secure Shell (SSH) Transport Layer ProtocolRFC 4716
The Secure Shell (SSH) Public Key File FormatRFC 5656
Elliptic Curve Algorithm Integration in the Secure Shell Transport LayerRFC 8332
Use of RSA Keys with SHA-256 and SHA-512 in the Secure Shell (SSH) ProtocolRFC 8731
Secure Shell (SSH) Key Exchange Method Using Curve25519 and Curve448draft-miller-ssh-agent-03
SSH Agent Protocoldraft-ietf-secsh-filexfer-02
SSH File Transfer Protocoldraft-dbider-sha2-mac-for-ssh-06
SHA-2 Data Integrity Verification for the Secure Shell (SSH) Transport Layer Protocol
Credits #
https://github.com/GreenAppers/dartssh by GreenAppers
License #
dartssh is released under the terms of the MIT license. See LICENSE.