Open a Forwarded Channel through an SSH Tunnel

See more Socket/SSL/TLS Examples

Demonstrates Socket.SshNewChannel, which opens a port-forwarded channel through an authenticated SSH tunnel to a destination host and port, populating a Socket with the connected channel.

#import <CkoSocket.h>
#import <NSString.h>

BOOL success = NO;

CkoSocket *socket = [[CkoSocket alloc] init];

//  Connect to the SSH server and initialize an SSH tunneling session.  Port 22 is conventional but
//  not required.
success = [socket SshOpenTunnel: @"ssh.example.com" sshPort: [NSNumber numberWithInt: 22]];
if (success == NO) {
    NSLog(@"%@",socket.LastErrorText);
    return;
}

//  Authenticate the SSH session before opening forwarded channels.
//  The SSH password should come from a secure source rather than being hard-coded.
NSString *sshPassword = @"mySshPassword";
success = [socket SshAuthenticatePw: @"sshUser" sshPassword: sshPassword];
if (success == NO) {
    NSLog(@"%@",socket.LastErrorText);
    return;
}

//  Open a port-forwarded channel through the authenticated SSH tunnel to the destination host and
//  port, populating a Socket with the connected channel.  Set the 3rd argument to true to establish
//  TLS to the destination inside the tunnel.
BOOL bTls = NO;
int maxWaitMs = 20000;
CkoSocket *channel = [[CkoSocket alloc] init];
success = [socket SshNewChannel: @"db.internal" port: [NSNumber numberWithInt: 5432] ssl: bTls maxWaitMs: [NSNumber numberWithInt: maxWaitMs] channel: channel];
if (success == NO) {
    NSLog(@"%@",socket.LastErrorText);
    return;
}

//  Use the channel socket to send and receive with the destination through the tunnel.
NSLog(@"%@",@"Forwarded channel opened to the destination.");