Objective-C

Start SSH Tunnel Keyboard-Interactive Authentication

Demonstrates the Chilkat SshTunnel.StartKeyboardAuth method, which begins keyboard-interactive authentication. The only argument is the login name. It returns XML describing the server's prompts, which are answered with ContinueKeyboardAuth.

Background: Keyboard-interactive is the prompt-driven authentication method: the server sends one or more questions — a password, a one-time code, a security question — and the client answers each. This is how a tunnel supports two-factor and other challenge-response schemes. The returned XML says exactly what to ask and whether to mask the input.

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Objective-C

#import <CkoSshTunnel.h>
#import <NSString.h>

BOOL success = NO;

//  Demonstrates the SshTunnel.StartKeyboardAuth method, which begins keyboard-interactive
//  authentication.  The only argument is the login name.  It returns XML describing the server's
//  prompts, which are answered with ContinueKeyboardAuth.

CkoSshTunnel *tunnel = [[CkoSshTunnel alloc] init];

//  The tunnel forwards accepted local connections to this destination through the SSH server.
tunnel.DestHostname = @"db.internal.example.com";
tunnel.DestPort = [NSNumber numberWithInt:5432];

//  Connect to the SSH server.  This performs the TCP/proxy connection and SSH handshake, but
//  does not authenticate yet.
int sshPort = 22;
success = [tunnel Connect: @"ssh.example.com" port: [NSNumber numberWithInt: sshPort]];
if (success == NO) {
    NSLog(@"%@",tunnel.LastErrorText);
    return;
}

//  Begin keyboard-interactive authentication.  The returned XML describes the server's prompts.
NSString *infoRequestXml = [tunnel StartKeyboardAuth: @"mySshLogin"];
if (tunnel.LastMethodSuccess == NO) {
    NSLog(@"%@",tunnel.LastErrorText);
    return;
}

NSLog(@"%@",infoRequestXml);

//  Answer the prompt(s) with ContinueKeyboardAuth, then call BeginAccepting.

BOOL waitForThreadExit = YES;
success = [tunnel CloseTunnel: waitForThreadExit];
if (success == NO) {
    NSLog(@"%@",tunnel.LastErrorText);
    return;
}