Objective-C

Start SFTP Keyboard-Interactive Authentication

Demonstrates the Chilkat SFtp.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: rather than assuming a single password, the server sends one or more questions — a password, a one-time code, a security question — and the client answers each. This is how SFTP supports two-factor and other challenge-response schemes. The returned XML tells you exactly what to ask and whether to mask the input.

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Objective-C

#import <CkoSFtp.h>
#import <NSString.h>

BOOL success = NO;

//  Demonstrates the SFtp.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.

CkoSFtp *sftp = [[CkoSFtp alloc] init];

//  Step 1: Connect the SSH transport.  Port 22 is the usual port.
int port = 22;
success = [sftp Connect: @"sftp.example.com" port: [NSNumber numberWithInt: port]];
if (success == NO) {
    NSLog(@"%@",sftp.LastErrorText);
    return;
}

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

NSLog(@"%@",infoRequestXml);

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

[sftp Disconnect];