C++

Get SSH Server Authentication Methods

Demonstrates getting the authentication methods advertised by an SSH server. Connect first but do not authenticate, then call GetAuthMethods, which returns a lowercase, comma-separated list such as publickey,password,keyboard-interactive.

Important: Querying the authentication methods intentionally disconnects from the server, so reconnect before authenticating.

Background: Knowing what a server accepts lets a client choose the right authentication path rather than guessing — for example, falling back to keyboard-interactive when password authentication is not offered, or failing fast with a clear message when only public-key is allowed. It is also useful diagnostically when authentication fails for reasons that are not obvious from the error text.

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C++

#include <CkSsh.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  Demonstrates getting the authentication methods advertised by an SSH server.

    CkSsh ssh;

    int port = 22;

    //  The server must be connected, but not yet authenticated.
    success = ssh.Connect("ssh.example.com",port);
    if (success == false) {
        std::cout << ssh.lastErrorText() << "\r\n";
        return;
    }

    //  Returns a lowercase, comma-separated list, such as:
    //      publickey,password,keyboard-interactive
    const char *authMethods = ssh.getAuthMethods();
    if (ssh.get_LastMethodSuccess() == false) {
        std::cout << ssh.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Authentication methods supported by this server: " << authMethods << "\r\n";

    //  IMPORTANT: Querying the authentication methods intentionally disconnects from the server.
    //  Reconnect before authenticating.
    success = ssh.Connect("ssh.example.com",port);
    if (success == false) {
        std::cout << ssh.lastErrorText() << "\r\n";
        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.
    const char *password = "mySshPassword";

    success = ssh.AuthenticatePw("mySshLogin",password);
    if (success == false) {
        std::cout << ssh.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "SSH authentication successful." << "\r\n";

    ssh.Disconnect();
    }