Unicode C

SFTP Authenticate with a SecureString Password and Private Key

Demonstrates the Chilkat SFtp.AuthenticateSecPwPk method, which authenticates using SecureString login and password objects together with a private key. The third argument is the SshKey private key.

Note: The private-key path is relative to the application's current working directory. Supply the path to your own key file.

Background: This is the SecureString form of two-factor SFTP authentication: the password is held encrypted in memory and combined with a private key for servers that require both. It is the most protective option when a deployment mandates two-factor SSH and you also want to minimize plaintext credential exposure in the process.

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Unicode C

#include <C_CkSFtpW.h>
#include <C_CkSshKeyW.h>
#include <C_CkSecureStringW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkSFtpW sftp;
    int port;
    const wchar_t *password;
    HCkSshKeyW privKey;
    const wchar_t *keyText;
    HCkSecureStringW secureLogin;
    HCkSecureStringW securePassword;

    success = FALSE;

    //  Demonstrates the SFtp.AuthenticateSecPwPk method, which authenticates using SecureString login
    //  and password objects together with a private key.  The 1st argument is the username, the 2nd
    //  is the password, and the 3rd is an SshKey private key.

    sftp = CkSFtpW_Create();

    //  Step 1: Connect the SSH transport.  Port 22 is the usual port.
    port = 22;
    success = CkSFtpW_Connect(sftp,L"sftp.example.com",port);
    if (success == FALSE) {
        wprintf(L"%s\n",CkSFtpW_lastErrorText(sftp));
        CkSFtpW_Dispose(sftp);
        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.
    password = L"mySshPassword";

    //  Load the SSH private key.  LoadText reads the file's text, which is then imported.
    privKey = CkSshKeyW_Create();
    keyText = CkSshKeyW_loadText(privKey,L"qa_data/id_rsa");
    if (CkSshKeyW_getLastMethodSuccess(privKey) == FALSE) {
        wprintf(L"%s\n",CkSshKeyW_lastErrorText(privKey));
        CkSFtpW_Dispose(sftp);
        CkSshKeyW_Dispose(privKey);
        return;
    }

    success = CkSshKeyW_FromOpenSshPrivateKey(privKey,keyText);
    if (success == FALSE) {
        wprintf(L"%s\n",CkSshKeyW_lastErrorText(privKey));
        CkSFtpW_Dispose(sftp);
        CkSshKeyW_Dispose(privKey);
        return;
    }

    //  Place the login and password into SecureString objects.
    secureLogin = CkSecureStringW_Create();
    CkSecureStringW_Append(secureLogin,L"mySshLogin");
    securePassword = CkSecureStringW_Create();
    CkSecureStringW_Append(securePassword,password);

    success = CkSFtpW_AuthenticateSecPwPk(sftp,secureLogin,securePassword,privKey);
    if (success == FALSE) {
        wprintf(L"%s\n",CkSFtpW_lastErrorText(sftp));
        CkSFtpW_Dispose(sftp);
        CkSshKeyW_Dispose(privKey);
        CkSecureStringW_Dispose(secureLogin);
        CkSecureStringW_Dispose(securePassword);
        return;
    }

    //  Step 3: Open the SFTP subsystem.  This must be done after authentication and before any
    //  file or directory operations.
    success = CkSFtpW_InitializeSftp(sftp);
    if (success == FALSE) {
        wprintf(L"%s\n",CkSFtpW_lastErrorText(sftp));
        CkSFtpW_Dispose(sftp);
        CkSshKeyW_Dispose(privKey);
        CkSecureStringW_Dispose(secureLogin);
        CkSecureStringW_Dispose(securePassword);
        return;
    }

    wprintf(L"Authenticated.\n");

    CkSFtpW_Disconnect(sftp);


    CkSFtpW_Dispose(sftp);
    CkSshKeyW_Dispose(privKey);
    CkSecureStringW_Dispose(secureLogin);
    CkSecureStringW_Dispose(securePassword);

    }