C# Signature:

    [DllImport("credui")]
    private static extern CredUIReturnCodes CredUIPromptForCredentials(ref CREDUI_INFO creditUR,
      string targetName,
      IntPtr reserved1,
      int iError,
      StringBuilder userName,
      int maxUserName,
      StringBuilder password,
      int maxPassword,
      [MarshalAs(UnmanagedType.Bool)] ref bool pfSave,
      CREDUI_FLAGS flags);

VB Signature:

    ''' <summary>
    ''' The CredUIPromptForWindowsCredentials function creates and displays a configurable dialog box that allows users to supply credential information by using any credential provider installed on the local computer.
    ''' NOTE: Windows Vista or Server 2008 or later ONLY. For older Windows versions use CredUIPromptForCredentials().
    ''' See http://msdn.microsoft.com/en-us/library/aa375178(v=VS.85).aspx
    ''' </summary>
    ''' <param name="pUiInfo">The CREDUI_INFO structure with customises the appearance of the dialog.</param>
    ''' <param name="dwAuthError">If prompting after an error pass the Windows Error code so the appropriate error message is included in the dialog.</param>
    ''' <param name="pulAuthPackage">Determine the authentication package to use. Pass zero to use default. Returns with identifier for package used.</param>
    ''' <param name="pvInAuthBuffer">An authentication buffer with which to default prompted values (see <see cref="CredPackAuthenticationBuffer" />).</param>
    ''' <param name="ulInAuthBufferSize">Size of the input authentication buffer.</param>
    ''' <param name="ppvOutAuthBuffer">An authentication buffer which will be populated with entered credentials (see <see cref="CredUnPackAuthenticationBuffer" />).</param>
    ''' <param name="pulOutAuthBufferSize">Size of the output authentication buffer.</param>
    ''' <param name="pfSave">If set to <c>True</c> the check the "Save" checkbox on teh dialog - only displayed if CREDUIWIN_CHECKBOX is passed in dwFlags.</param>
    ''' <param name="dwFlags">Flags to control the dialog functionality (see <see cref="CredUIWinFlags" />.</param>
    ''' <returns>A <see cref="CredUIReturnCodes" /> value.</returns>
    <System.Runtime.InteropServices.DllImport("credui.dll", EntryPoint:="CredUIPromptForWindowsCredentials", CharSet:=CharSet.Unicode)> <CLSCompliant(False)> _
    Public Shared Function CredUIPromptForWindowsCredentials(ByRef pUiInfo As CREDUI_INFO, _
                                ByVal dwAuthError As UInt32, _
                                ByRef pulAuthPackage As UInt32, _
                                ByVal pvInAuthBuffer As IntPtr, _
                                ByVal ulInAuthBufferSize As UInt32, _
                                ByRef ppvOutAuthBuffer As IntPtr, _
                                ByRef pulOutAuthBufferSize As UInt32, _
                                <MarshalAs(UnmanagedType.Bool)> ByRef pfSave As Boolean, _
                                ByVal dwFlags As CredUIWinFlags) As CredUIReturnCodes
    End Function

User-Defined Types:

    [Flags]
    enum CREDUI_FLAGS
    {
    INCORRECT_PASSWORD = 0x1,
    DO_NOT_PERSIST = 0x2,
    REQUEST_ADMINISTRATOR = 0x4,
    EXCLUDE_CERTIFICATES = 0x8,
    REQUIRE_CERTIFICATE = 0x10,
    SHOW_SAVE_CHECK_BOX = 0x40,
    ALWAYS_SHOW_UI = 0x80,
    REQUIRE_SMARTCARD = 0x100,
    PASSWORD_ONLY_OK = 0x200,
    VALIDATE_USERNAME = 0x400,
    COMPLETE_USERNAME = 0x800,
    PERSIST = 0x1000,
    SERVER_CREDENTIAL = 0x4000,
    EXPECT_CONFIRMATION = 0x20000,
    GENERIC_CREDENTIALS = 0x40000,
    USERNAME_TARGET_CREDENTIALS = 0x80000,
    KEEP_USERNAME = 0x100000,
    }

    public enum CredUIReturnCodes
    {
    NO_ERROR = 0,
    ERROR_CANCELLED = 1223,
    ERROR_NO_SUCH_LOGON_SESSION = 1312,
    ERROR_NOT_FOUND = 1168,
    ERROR_INVALID_ACCOUNT_NAME = 1315,
    ERROR_INSUFFICIENT_BUFFER = 122,
    ERROR_INVALID_PARAMETER = 87,
    ERROR_INVALID_FLAGS = 1004,
    }

VB Syntax:

    <Flags()> _
    Public Enum CredUIWinFlags As Integer
    CredUIWin_Generic = &H1
    CredUIWin_Checkbox = &H2
    CredUIWin_AuthPackage_Only = &H10
    CredUIWin_InCred_Only = &H20
    CredUIWin_Enumerate_Admins = &H100
    CredUIWin_Enumerate_CurrentUser = &H200
    CredUIWin_Secure_Prompt = &H1000
    CredUIWin_Pack_32_Wow = &H10000000
    End Enum

    Public Enum CredUIReturnCodes As Integer
    NO_ERROR = 0
    ERROR_CANCELLED = 1223
    ERROR_NO_SUCH_LOGON_SESSION = 1312
    ERROR_NOT_FOUND = 1168
    ERROR_INVALID_ACCOUNT_NAME = 1315
    ERROR_INSUFFICIENT_BUFFER = 122
    ERROR_INVALID_PARAMETER = 87
    ERROR_INVALID_FLAGS = 1004
    End Enum

Also see [CREDUI_INFO}.

Alternative Managed API:

Do you know one? Please contribute it!

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code:

    /// <summary>
    /// Prompts for password.
    /// </summary>
    /// <param name="user">The user.</param>
    /// <param name="password">The password.</param>
    /// <returns>True if no errors.</returns>
    internal static bool PromptForPassword(out string user, out string password)
    {
    // Setup the flags and variables
    StringBuilder userPassword = new StringBuilder(), userID = new StringBuilder();
    CREDUI_INFO credUI = new CREDUI_INFO();
    credUI.cbSize = Marshal.SizeOf(credUI);
    bool save = false;
    CREDUI_FLAGS flags = CREDUI_FLAGS.ALWAYS_SHOW_UI | CREDUI_FLAGS.GENERIC_CREDENTIALS;

    // Prompt the user
    CredUIReturnCodes returnCode = CredUIPromptForCredentials(ref credUI, Application.ProductName, IntPtr.Zero, 0, userID, 100, userPassword, 100, ref save, flags);

    user = userID.ToString();
    password = userPassword.ToString();

    return (returnCode == CredUIReturnCodes.NO_ERROR);
    }

Please edit this page!

Do you have...

• helpful tips or sample code to share for using this API in managed code?
• corrections to the existing content?
• variations of the signature you want to share?
• additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).