- 1 year ago
LogonUser with JNA leads to "unknown user name or bad password"
When using JNA (Java Native Access) to call the Windows LogonUser
function, there are a few potential reasons why you might encounter the "unknown user name or bad password" error:
Incorrect Username or Domain: Double-check that you are providing the correct username and domain (if applicable) to the
LogonUser
function. Ensure there are no leading or trailing spaces in the input.Password Encoding: Make sure that the password is correctly encoded before passing it to the
LogonUser
function. If the password is not encoded correctly, it may result in an "unknown user name or bad password" error. Typically, the password should be converted to a null-terminated character array (C-style string) before passing it to the function.User Privileges: The user account attempting to log on may not have the necessary privileges to perform the logon operation. Ensure that the user has the appropriate logon privileges on the system.
Logon Type: The
LogonUser
function requires you to specify the logon type, which can be eitherLOGON32_LOGON_INTERACTIVE
(interactive logon) orLOGON32_LOGON_BATCH
(batch logon). Make sure you are using the correct logon type for your scenario.Trusted Domain: If you are logging on using a domain account, ensure that the domain is trusted by the local system. If the domain is not trusted, the logon operation may fail.
Here's a basic example of how to call the LogonUser
function using JNA:
javaimport com.sun.jna.Native;
import com.sun.jna.platform.win32.Advapi32;
import com.sun.jna.platform.win32.WinBase;
import com.sun.jna.platform.win32.WinNT;
public class LogonUserExample {
public static void main(String[] args) {
String username = "your_username";
String password = "your_password";
String domain = "your_domain"; // If logging on using a domain account
Advapi32 advapi32 = Advapi32.INSTANCE;
WinNT.HANDLEByReference phToken = new WinNT.HANDLEByReference();
boolean result = advapi32.LogonUser(username, domain, password, WinBase.LOGON32_LOGON_INTERACTIVE,
WinBase.LOGON32_PROVIDER_DEFAULT, phToken);
if (result) {
System.out.println("Logon successful!");
// Use the token for privileged operations, if needed.
// Close the token handle when done using it.
Kernel32.INSTANCE.CloseHandle(phToken.getValue());
} else {
System.out.println("Logon failed. Error code: " + Kernel32.INSTANCE.GetLastError());
}
}
}
Ensure that you have the appropriate permissions to perform the logon operation. If you are still encountering the error after verifying the above points, double-check the provided credentials and consult the Windows Event Viewer for more detailed error information.