c# - 在 Windows 7 上调用 IPrincipal.IsInRole

Question

我们在应用程序中使用 NTLM 身份验证来确定用户是否可以执行某些操作。我们使用 IPrincipal他们当前的 Windows 登录(在 WinForms 应用程序中)，调用 IsInRole检查特定的组成员。

要检查用户是否是机器上的本地管理员，我们使用:

AppDomain.CurrentDomain.SetPrincipalPolicy(PrincipalPolicy.WindowsPrincipal);
...
bool allowed = Thread.CurrentPrincipal.IsInRole(@"Builtin\Administrators")

如果当前用户是 Administrator 用户，或者是 Builtin\Administrators 组成员的另一个用户，这将起作用。

在我们对 Windows 7 的测试中，我们发现这不再按预期工作。 Administrator 用户仍然可以正常工作，但属于 Builtin\Administrators 组成员的任何其他用户都会为 IsInRole 调用返回 false。

是什么导致了这种差异？我有一种直觉，默认设置已在某处更改(可能在 gpedit 中)，但找不到任何看起来像罪魁祸首的东西。

Answer 1

问题是 Windows 安全(又名“UAC”)妨碍了您。对管理员角色有特殊处理，您的用户在提升之前实际上不会拥有这些角色。管理员角色在某种意义上是“幽灵”:存在但无法进行权限检查，甚至无法(轻松)测试是否存在。请参阅注释: http://msdn.microsoft.com/en-us/library/46ks97y7.aspx

这是一个讨论该问题的系列，其中包含执行必要解决方法的示例代码:

• http://www.simple-talk.com/community/blogs/dana/archive/2008/03/17/45354.aspx
• http://www.simple-talk.com/community/blogs/dana/archive/2008/03/17/45352.aspx

我通过构建自己的 UAC 提示并使用名称和密码调用 Win32 登录 API 解决了 ASP.NET 应用程序中的类似问题。您可能很幸运能够使用 .NET 桌面应用程序，在这种情况下您可以使用常规提升请求。

这里有一些 C# 代码可以在不提升权限的情况下检查管理员权限。

    public const UInt32 TOKEN_DUPLICATE = 0x0002;
    public const UInt32 TOKEN_IMPERSONATE = 0x0004;
    public const UInt32 TOKEN_QUERY = 0x0008;

    public enum TOKEN_ELEVATION_TYPE
    {
        TokenElevationTypeDefault = 1,
        TokenElevationTypeFull,
        TokenElevationTypeLimited
    }

    public enum TOKEN_INFORMATION_CLASS
    {
        TokenUser = 1,
        TokenGroups,
        TokenPrivileges,
        TokenOwner,
        TokenPrimaryGroup,
        TokenDefaultDacl,
        TokenSource,
        TokenType,
        TokenImpersonationLevel,
        TokenStatistics,
        TokenRestrictedSids,
        TokenSessionId,
        TokenGroupsAndPrivileges,
        TokenSessionReference,
        TokenSandBoxInert,
        TokenAuditPolicy,
        TokenOrigin,
        TokenElevationType,
        TokenLinkedToken,
        TokenElevation,
        TokenHasRestrictions,
        TokenAccessInformation,
        TokenVirtualizationAllowed,
        TokenVirtualizationEnabled,
        TokenIntegrityLevel,
        TokenUIAccess,
        TokenMandatoryPolicy,
        TokenLogonSid,
        MaxTokenInfoClass  // MaxTokenInfoClass should always be the last enum 
    }

    public enum SECURITY_IMPERSONATION_LEVEL
    {
        SecurityAnonymous,
        SecurityIdentification,
        SecurityImpersonation,
        SecurityDelegation
    }


    public static bool IsAdmin()
    {
        var identity = WindowsIdentity.GetCurrent();
        return (null != identity && new WindowsPrincipal(identity).IsInRole(WindowsBuiltInRole.Administrator));
    }

    /// <summary>
    /// The function checks whether the primary access token of the process belongs
    /// to user account that is a member of the local Administrators group, even if
    /// it currently is not elevated.
    /// </summary>
    /// <returns>
    /// Returns true if the primary access token of the process belongs to user
    /// account that is a member of the local Administrators group. Returns false
    /// if the token does not.
    /// </returns>
    public static bool CanBeAdmin()
    {
        bool fInAdminGroup = false;
        IntPtr hToken = IntPtr.Zero;
        IntPtr hTokenToCheck = IntPtr.Zero;
        IntPtr pElevationType = IntPtr.Zero;
        IntPtr pLinkedToken = IntPtr.Zero;
        int cbSize = 0;

        if (IsAdmin())
            return true;

        try
        {
            // Check the token for this user
            hToken = WindowsIdentity.GetCurrent().Token;

            // Determine whether system is running Windows Vista or later operating
            // systems (major version >= 6) because they support linked tokens, but
            // previous versions (major version < 6) do not.
            if (Environment.OSVersion.Version.Major >= 6)
            {
                // Running Windows Vista or later (major version >= 6).
                // Determine token type: limited, elevated, or default.

                // Allocate a buffer for the elevation type information.
                cbSize = sizeof(TOKEN_ELEVATION_TYPE);
                pElevationType = Marshal.AllocHGlobal(cbSize);
                if (pElevationType == IntPtr.Zero)
                {
                    throw new Win32Exception(Marshal.GetLastWin32Error());
                }

                // Retrieve token elevation type information.
                if (!GetTokenInformation(hToken,
                    TOKEN_INFORMATION_CLASS.TokenElevationType, pElevationType, cbSize, out cbSize))
                {
                    throw new Win32Exception(Marshal.GetLastWin32Error());
                }

                // Marshal the TOKEN_ELEVATION_TYPE enum from native to .NET.
                TOKEN_ELEVATION_TYPE elevType = (TOKEN_ELEVATION_TYPE)Marshal.ReadInt32(pElevationType);

                // If limited, get the linked elevated token for further check.
                if (elevType == TOKEN_ELEVATION_TYPE.TokenElevationTypeLimited)
                {
                    // Allocate a buffer for the linked token.
                    cbSize = IntPtr.Size;
                    pLinkedToken = Marshal.AllocHGlobal(cbSize);
                    if (pLinkedToken == IntPtr.Zero)
                    {
                        throw new Win32Exception(Marshal.GetLastWin32Error());
                    }

                    // Get the linked token.
                    if (!GetTokenInformation(hToken,
                        TOKEN_INFORMATION_CLASS.TokenLinkedToken, pLinkedToken,
                        cbSize, out cbSize))
                    {
                        throw new Win32Exception(Marshal.GetLastWin32Error());
                    }

                    // Marshal the linked token value from native to .NET.
                    hTokenToCheck = Marshal.ReadIntPtr(pLinkedToken);
                }
            }

            // CheckTokenMembership requires an impersonation token. If we just got
            // a linked token, it already is an impersonation token.  If we did not
            // get a linked token, duplicate the original into an impersonation
            // token for CheckTokenMembership.
            if (hTokenToCheck == IntPtr.Zero)
            {
                if (!DuplicateToken(hToken, (int)SECURITY_IMPERSONATION_LEVEL.SecurityIdentification, ref hTokenToCheck))
                {
                    throw new Win32Exception(Marshal.GetLastWin32Error());
                }
            }

            // Check if the token to be checked contains admin SID.
            WindowsIdentity id = new WindowsIdentity(hTokenToCheck);
            WindowsPrincipal principal = new WindowsPrincipal(id);
            fInAdminGroup = principal.IsInRole(WindowsBuiltInRole.Administrator);
        }
        catch
        {
            return false;
        }
        finally
        {
            // Centralized cleanup for all allocated resources.
            if (pElevationType != IntPtr.Zero)
            {
                Marshal.FreeHGlobal(pElevationType);
                pElevationType = IntPtr.Zero;
            }
            if (pLinkedToken != IntPtr.Zero)
            {
                Marshal.FreeHGlobal(pLinkedToken);
                pLinkedToken = IntPtr.Zero;
            }
        }

        return fInAdminGroup;
    }

改编自网上某处的一篇文章，不好意思，出处没了。