Start SFTP Keyboard-Interactive Authentication

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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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#include <C_CkSFtp.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkSFtp sftp;
    int port;
    const char *infoRequestXml;

    success = FALSE;

    //  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.

    sftp = CkSFtp_Create();

    //  Step 1: Connect the SSH transport.  Port 22 is the usual port.
    port = 22;
    success = CkSFtp_Connect(sftp,"sftp.example.com",port);
    if (success == FALSE) {
        printf("%s\n",CkSFtp_lastErrorText(sftp));
        CkSFtp_Dispose(sftp);
        return;
    }

    //  Begin keyboard-interactive authentication.  The returned XML describes the server's prompts.
    infoRequestXml = CkSFtp_startKeyboardAuth(sftp,"mySshLogin");
    if (CkSFtp_getLastMethodSuccess(sftp) == FALSE) {
        printf("%s\n",CkSFtp_lastErrorText(sftp));
        CkSFtp_Dispose(sftp);
        return;
    }

    printf("%s\n",infoRequestXml);

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

    CkSFtp_Disconnect(sftp);


    CkSFtp_Dispose(sftp);

    }