LogonUser function

The LogonUser function attempts to log a user on to the local computer. The function authenticates the user, and, if successful, returns a handle to an access token that represents the logged-on user.

Syntax

BOOL LogonUserA(
  LPCSTR  lpszUsername,
  LPCSTR  lpszDomain,
  LPCSTR  lpszPassword,
  DWORD   dwLogonType,
  DWORD   dwLogonProvider,
  PHANDLE phToken
);

BOOL LogonUserW(
  LPCWSTR lpszUsername,
  LPCWSTR lpszDomain,
  LPCWSTR lpszPassword,
  DWORD   dwLogonType,
  DWORD   dwLogonProvider,
  PHANDLE phToken
);

Parameters

Name	Type	Description
lpszUsername	LPCSTR/W	Pointer to a null-terminated string that specifies the name of the user.
lpszDomain	LPCSTR/W	Pointer to a null-terminated string that specifies the domain or local computer name.
lpszPassword	LPCSTR/W	Pointer to a null-terminated string that specifies the password.
dwLogonType	DWORD	Type of logon operation. See table below.
dwLogonProvider	DWORD	Logon provider. Usually `LOGON32_PROVIDER_DEFAULT`.
phToken	PHANDLE	Pointer to a handle that receives the token.

Logon type values

Constant	Value	Meaning
LOGON32_LOGON_INTERACTIVE	2	Logon by user with interactive logon rights.
LOGON32_LOGON_NETWORK	3	Network logon, no profile loaded.
LOGON32_LOGON_BATCH	4	Batch logon for scheduled tasks.
LOGON32_LOGON_SERVICE	5	Logon for service accounts.
LOGON32_LOGON_UNLOCK	7	Unlock workstation.

Return value

If the function succeeds, the return value is non‑zero. If it fails, the return value is zero. Call GetLastError for extended error information.

Remarks

The caller must have the SE_TCB_NAME privilege to call this function with LOGON32_LOGON_SERVICE or LOGON32_LOGON_BATCH.
The token returned by LogonUser can be used with ImpersonateLoggedOnUser or CreateProcessAsUser.
Use LogonUserW for Unicode support. Prefer the wide version in new code.
When logging on with LOGON32_LOGON_INTERACTIVE, the user profile is loaded. This may affect performance.

Example

#include <windows.h>
#include <stdio.h>

int main()
{
    HANDLE hToken = NULL;
    BOOL  ok = LogonUserA(
        "UserName",       // user name
        "Domain",         // domain or local computer
        "Password123",   // password
        LOGON32_LOGON_INTERACTIVE,
        LOGON32_PROVIDER_DEFAULT,
        &hToken);

    if (ok) {
        printf("Logon successful. Token: %p\n", hToken);
        CloseHandle(hToken);
    } else {
        printf("Logon failed. Error: %lu\\n", GetLastError());
    }
    return 0;
}