如何检查[UserName]和[Password]的用户是否是[DomainName]的域管理员而没有模拟？

Question

Impersonation example

I can check is user domain administrator with next lines of code:

using (Impersonation im = new Impersonation(UserName, Domain, Password))
{
    System.Security.Principal.WindowsIdentity identity = System.Security.Principal.WindowsIdentity.GetCurrent();
    bool isDomainAdmin = identity.IsDomainAdmin(Domain, UserName, Password);
    if (!isDomainAdmin)
    {
        //deny access, for example
    }
}

where IsDomainAdmin - is extension method

public static bool IsDomainAdmin(this WindowsIdentity identity, string domain, string userName, string password)
{
    Domain d = Domain.GetDomain(new DirectoryContext(DirectoryContextType.Domain, domain, userName, password));

    using (DirectoryEntry de = d.GetDirectoryEntry())
    {
        byte[] domainSIdArray = (byte[])de.Properties["objectSid"].Value;
        SecurityIdentifier domainSId = new SecurityIdentifier(domainSIdArray, 0);
        SecurityIdentifier domainAdminsSId = new SecurityIdentifier(WellKnownSidType.AccountDomainAdminsSid, domainSId);
        WindowsPrincipal wp = new WindowsPrincipal(identity);
        return wp.IsInRole(domainAdminsSId);
    }
}

But, when method IsDomainAdmin is called, it is trying to write some files to the %LOCALAPPDATA% for impersonated user, and if program is runnig not as administrator, it throws an exception

Could not load file or assembly 'System.DirectoryServices, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. Either a required impersonation level was not provided, or the provided impersonation level is invalid. (Exception from HRESULT: 0x80070542)

Answer 1

You certainly don't need a user's password to verify if the user is a member of a group. So why don't you just query AD in a straight-forward manner using DirectoryEntry or DirectorySearcher ? If you also need to verify that the password supplied is correct you can do that in an additional step using PrincipalContext.ValidateCredentials . (See PrincipalContext.ValidateCredentials Method (String, String) ).

static void Main(string[] args) {
    string userDomain = "somedomain";
    string userName = "username";
    string password = "apassword";

    if (IsDomainAdmin(userDomain, userName)) {
        string fullUserName = userDomain + @"\" + userName;
        PrincipalContext context = new PrincipalContext(
            ContextType.Domain, userDomain);
        if (context.ValidateCredentials(fullUserName, password)) {
            Console.WriteLine("Success!");
        }
    }
}

public static bool IsDomainAdmin(string domain, string userName) {
    string adminDn = GetAdminDn(domain);
    SearchResult result = (new DirectorySearcher(
        new DirectoryEntry("LDAP://" + domain),
        "(&(objectCategory=user)(samAccountName=" + userName + "))",
        new[] { "memberOf" })).FindOne();
    return result.Properties["memberOf"].Contains(adminDn);
}

public static string GetAdminDn(string domain) {
    return (string)(new DirectorySearcher(
        new DirectoryEntry("LDAP://" + domain),
        "(&(objectCategory=group)(cn=Domain Admins))")
        .FindOne().Properties["distinguishedname"][0]);
}

Answer 2

We are modified @jmh_gr answer, and it seems to become independent from "Domain Admins" group name.

static string BuildOctetString(SecurityIdentifier sid)
{
    byte[] items = new byte[sid.BinaryLength];
    sid.GetBinaryForm(items, 0);
    StringBuilder sb = new StringBuilder();
    foreach (byte b in items)
    {
        sb.Append(b.ToString("X2"));
    }
    return sb.ToString();
}
public static bool IsDomainAdmin(string domain, string userName)
{
    using (DirectoryEntry domainEntry = new DirectoryEntry(string.Format("LDAP://{0}", domain)))
    {
        byte[] domainSIdArray = (byte[])domainEntry.Properties["objectSid"].Value;

        SecurityIdentifier domainSId = new SecurityIdentifier(domainSIdArray, 0);
        SecurityIdentifier domainAdminsSId = new SecurityIdentifier(WellKnownSidType.AccountDomainAdminsSid, domainSId);

        using (DirectoryEntry groupEntry = new DirectoryEntry(string.Format("LDAP://<SID={0}>", BuildOctetString(domainAdminsSId))))
        {
            string adminDn = groupEntry.Properties["distinguishedname"].Value as string;
            SearchResult result = (new DirectorySearcher(domainEntry, string.Format("(&(objectCategory=user)(samAccountName={0}))", userName), new[] { "memberOf" })).FindOne();
            return result.Properties["memberOf"].Contains(adminDn);
        }
    }
}

Anyway, thanks to @jmh_gr for the answer.

Answer 3

Using this code by @lluisfranco

using System.DirectoryServices;
using System.DirectoryServices.ActiveDirectory;
using System.Net.NetworkInformation;
using System.Security.Principal;

namespace Alpha.Code
{
    public static class SecurityExtensions
    {
        public static bool IsDomainAdmin (this WindowsIdentity identity)
        {
            Domain d = Domain.GetDomain(new
                DirectoryContext(DirectoryContextType.Domain, getDomainName()));
            using (DirectoryEntry de = d.GetDirectoryEntry())
            {
                byte[] bdomSid = (byte[])de.Properties["objectSid"].Value;
                string sdomainSid = sIDtoString(bdomSid);
                WindowsPrincipal wp = new WindowsPrincipal(identity);
                SecurityIdentifier dsid = new SecurityIdentifier(sdomainSid);
                SecurityIdentifier dasid = new SecurityIdentifier(
                    WellKnownSidType.AccountDomainAdminsSid, dsid);
                return wp.IsInRole(dasid);
            }
        }

        public static string getDomainName()
        {
            return IPGlobalProperties.GetIPGlobalProperties().DomainName;
        }

        public static string sIDtoString(byte[] sidBinary)
        {
            SecurityIdentifier sid = new SecurityIdentifier(sidBinary, 0);
            return sid.ToString();
        }
    }
}

Usage sample:

if (WindowsIdentity.GetCurrent().IsDomainAdmin())
{
    //Actions to do if user is domain admin
}

Source:
http://geeks.ms/blogs/lfranco/archive/2009/11/25/how-to-191-como-saber-si-el-usuario-actual-es-administrador-del-dominio.aspx