Objective-C

Continue SFTP Keyboard-Interactive Authentication

Demonstrates the Chilkat SFtp.ContinueKeyboardAuth method, which submits a response to a keyboard-interactive prompt. The only argument is the response text; for a request with multiple prompts, an XML response is supplied instead. It returns XML indicating the next prompt or the final result.

Background: This is the second half of the exchange started by StartKeyboardAuth. A server may issue several rounds of prompts, so a robust client loops: submit answers, read the returned XML, and continue until it sees success or failure. On success, remember that InitializeSftp still must be called before any file operation.

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Objective-C

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

BOOL success = NO;

//  Demonstrates the SFtp.ContinueKeyboardAuth method, which submits a response to a
//  keyboard-interactive prompt.  The only argument is the response.  For multiple prompts, an
//  XML response is supplied instead.

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 to receive the server's prompt(s).
NSString *infoRequestXml = [sftp StartKeyboardAuth: @"mySshLogin"];
if (sftp.LastMethodSuccess == NO) {
    NSLog(@"%@",sftp.LastErrorText);
    return;
}

//  Normally you would not hard-code the password in source.  You should instead obtain it
//  from an interactive prompt, environment variable, or a secrets vault.
NSString *password = @"mySshPassword";

//  Submit the response (typically the password).  The returned XML indicates the next prompt or
//  the final result.
NSString *result = [sftp ContinueKeyboardAuth: password];
if (sftp.LastMethodSuccess == NO) {
    NSLog(@"%@",sftp.LastErrorText);
    return;
}

NSLog(@"%@",result);

//  On success, initialize the SFTP subsystem.
success = [sftp InitializeSftp];
if (success == NO) {
    NSLog(@"%@",sftp.LastErrorText);
    return;
}

[sftp Disconnect];