See if user is part of Active Directory group in C# + Asp.net

Question

I need a way to see if a user is part of an active directory group from my .Net 3.5 asp.net c# application.

I am using the standard ldap authentication example off of msdn but I don't really see how to check against a group.

Overdo

Answer 1

With 3.5 and System.DirectoryServices.AccountManagement this is a bit cleaner:

public List<string> GetGroupNames(string userName)
{
  var pc = new PrincipalContext(ContextType.Domain);
  var src = UserPrincipal.FindByIdentity(pc, userName).GetGroups(pc);
  var result = new List<string>();
  src.ToList().ForEach(sr => result.Add(sr.SamAccountName));
  return result;
}

Obstacle

I get this error on the code listed: Unknown error (0x80005000) Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Runtime.InteropServices.COMException: Unknown error (0x80005000) The line causing it is: "var src = UserPrincipal.FindByIdentity(pc, userName).GetGroups(pc);" Any suggestions on what the problem could be? I copied the function as-is from your example. – Gerund

@Gerund are you sure the account you're using has permissions to query AD? Many places have anonymous binds disabled – Obstacle

I'm using .NET 4.0 and I had to change this line, var pc = new PrincipalContext(ContextType.Domain); to var pc = new PrincipalContext(ContextType.Domain, "MyDomainHere"); To get rid of the exception. After that works perfectly. – Antilebanon

@NickCraver why are you not disposing PrincipalContext and UserPrincipal ? – Fiddlededee

Answer 2

Nick Craver's solution doesn't work for me in .NET 4.0. I get an error about an unloaded AppDomain. Instead of using that, I used this (we only have one domain). This will check groups of groups as well as direct group membership.

using System.DirectoryServices.AccountManagement;
using System.Linq;

...

using (var ctx = new PrincipalContext(ContextType.Domain, yourDomain)) {
    using (var grp = GroupPrincipal.FindByIdentity(ctx, IdentityType.Name, yourGroup)) {
        bool isInRole = grp != null && 
            grp
            .GetMembers(true)
            .Any(m => m.SamAccountName == me.Identity.Name.Replace(yourDomain + "\\", ""));
    }
}

Basset

While i use this code, i am getting compilation error on .Any() method saying no extension method. Do i need to add any other using or reference? – Spenserian

@Antoops - you need to add a using statement for System.Linq – Relativity

+1 for showing how to use GetMembers(true), which was exactly what I needed to recursively check for group members! – Relativity

Answer 3

The code below will work in .net 4.0

private static string[] GetGroupNames(string userName)
{
    List<string> result = new List<string>();

    using (PrincipalContext pc = new PrincipalContext(ContextType.Domain, "YOURDOMAIN"))
    {
        using (PrincipalSearchResult<Principal> src = UserPrincipal.FindByIdentity(pc, userName).GetGroups(pc))
        {
            src.ToList().ForEach(sr => result.Add(sr.SamAccountName));
        }
    }

    return result.ToArray();
}

Lebkuchen

Good answer. Thank you. A couple very minor fixes: initalize result to the type you want to return - i.e. list or array. replace this line: src.ToList().ForEach(sr => result.Add(sr.SamAccountName)); with this: result = src.Select(x => x.SamAccountName).ToList(); // ToArray if you prefer – Raptorial

Answer 4

Simplest Solution

PrincipalContext pc = new PrincipalContext((Environment.UserDomainName == Environment.MachineName ? ContextType.Machine : ContextType.Domain), Environment.UserDomainName);

GroupPrincipal gp = GroupPrincipal.FindByIdentity(pc, "{GroupName}");
UserPrincipal up = UserPrincipal.FindByIdentity(pc, Environment.UserName);
up.IsMemberOf(gp);

Gracielagracile

Answer 5

This method might be helpful if you're trying to determine if the Windows authenticated current user is in a particular role.

public static bool CurrentUserIsInRole(string role)
{
    try
    {
        return System.Web.HttpContext.Current.Request
                    .LogonUserIdentity
                    .Groups
                    .Any(x => x.Translate(typeof(NTAccount)).ToString() == role);
        }
        catch (Exception) { return false; }
    }

Osmic

Answer 6

It depends on what you mean by if a user is in an AD group. In AD, groups can be a Security group or Distribution group. Even for security groups, it depends on if groups like "Domain Users" or "Users" need to be included in the membership check.

IsUserInSecurityGroup will only check for security groups and will work for Primary Group kind of groups like "Domain Users" and "Users", and not distribution groups. It will also solve the issue with nested groups. IsUserInAllGroup will also check for Distribution groups, but I am not sure if you would run into permission issues. If you do, use a service account that is in WAAG (See MSDN)

The reason I am not using UserPrincipal.GetAuthorizedGroups() is because it has a lot of issues, such as requiring the calling account to be in WAAG and requiring there isn't an entry in SidHistory (See David Thomas' comment)

public bool IsUserInSecurityGroup(string user, string group)
    {
        return IsUserInGroup(user, group, "tokenGroups");
    }
    public bool IsUserInAllGroup(string user, string group)
    {
        return IsUserInGroup(user, group, "tokenGroupsGlobalAndUniversal");
    }

    private bool IsUserInGroup(string user, string group, string groupType)
    {
        var userGroups = GetUserGroupIds(user, groupType);
        var groupTokens = ParseDomainQualifiedName(group, "group");
        using (var groupContext = new PrincipalContext(ContextType.Domain, groupTokens[0]))
        {
            using (var identity = GroupPrincipal.FindByIdentity(groupContext, IdentityType.SamAccountName, groupTokens[1]))
            {
                if (identity == null)
                    return false;

                return userGroups.Contains(identity.Sid);
            }
        }
    }
    private List<SecurityIdentifier> GetUserGroupIds(string user, string groupType)
    {
        var userTokens = ParseDomainQualifiedName(user, "user");
        using (var userContext = new PrincipalContext(ContextType.Domain, userTokens[0]))
        {
            using (var identity = UserPrincipal.FindByIdentity(userContext, IdentityType.SamAccountName, userTokens[1]))
            {
                if (identity == null)
                    return new List<SecurityIdentifier>();

                var userEntry = identity.GetUnderlyingObject() as DirectoryEntry;
                userEntry.RefreshCache(new[] { groupType });
                return (from byte[] sid in userEntry.Properties[groupType]
                        select new SecurityIdentifier(sid, 0)).ToList();
            }
        }
    }
    private static string[] ParseDomainQualifiedName(string name, string parameterName)
    {
        var groupTokens = name.Split(new[] {"\\"}, StringSplitOptions.RemoveEmptyEntries);
        if (groupTokens.Length < 2)
            throw new ArgumentException(Resources.Exception_NameNotDomainQualified + name, parameterName);
        return groupTokens;
    }

Mcmichael

All other answers are wrong to me because they don't take care of nested groups. Thanks. – Lundin

Answer 7

Here is my 2 cents.

    static void CheckUserGroup(string userName, string userGroup)
    {
        var wi = new WindowsIdentity(userName);
        var wp = new WindowsPrincipal(wi);

        bool inRole = wp.IsInRole(userGroup);

        Console.WriteLine("User {0} {1} member of {2} AD group", userName, inRole ? "is" : "is not", userGroup);
    }

Eades

Answer 8

This seems much simpler:

public bool IsInRole(string groupname)
{
    var myIdentity = WindowsIdentity.GetCurrent();
    if (myIdentity == null) return false;

    var myPrincipal = new WindowsPrincipal(myIdentity);
    var result = myPrincipal.IsInRole(groupname);

    return result;
}

Basildon

Answer 9

How about this

How to write LDAP query to test if user is member of a group?

Panayiotis

Answer 10

You could try the following code:

public bool Check_If_Member_Of_AD_Group(string username, string grouptoCheck, string domain, string ADlogin, string ADpassword)
{
    
     try {
        
        string EntryString = null;
        EntryString = "LDAP://" + domain;
        
        DirectoryEntry myDE = default(DirectoryEntry);
        
        grouptoCheck = grouptoCheck.ToLower();
        
        
        myDE = new DirectoryEntry(EntryString, ADlogin, ADpassword);
        
        DirectorySearcher myDirectorySearcher = new DirectorySearcher(myDE);
        
        myDirectorySearcher.Filter = "sAMAccountName=" + username;
        
        myDirectorySearcher.PropertiesToLoad.Add("MemberOf");
        
        SearchResult myresult = myDirectorySearcher.FindOne();
        
        int NumberOfGroups = 0;
        
        NumberOfGroups = myresult.Properties["memberOf"].Count - 1;
        
        string tempString = null;
        
        while ((NumberOfGroups >= 0)) {
            
            tempString = myresult.Properties["MemberOf"].Item[NumberOfGroups];
            tempString = tempString.Substring(0, tempString.IndexOf(",", 0));
            
            tempString = tempString.Replace("CN=", "");
            
            tempString = tempString.ToLower();
            tempString = tempString.Trim();
            
            if ((grouptoCheck == tempString)) {
                
                    
                return true;
            }
            
                
            NumberOfGroups = NumberOfGroups - 1;
        }
        
            
        return false;
    }
    catch (Exception ex) {
        
        System.Diagnostics.Debugger.Break();
    }
    //HttpContext.Current.Response.Write("Error: <br><br>" & ex.ToString)
}

Davidoff

As with BC's answer the above code will not test for nested membership – Davidoff

Answer 11

Brandon Johnson, loved it, I used what you had, but made the following change:

private static string[] GetGroupNames(string domainName, string userName)
{
    List<string> result = new List<string>();

    using (PrincipalContext principalContext = new PrincipalContext(ContextType.Domain, domainName))
    {
        using (PrincipalSearchResult<Principal> src = UserPrincipal.FindByIdentity(principalContext, userName).GetGroups(principalContext))
        {
            src.ToList().ForEach(sr => result.Add(sr.SamAccountName));
        }
    }

    return result.ToArray();
}

Apportionment

Answer 12

var context = new PrincipalContext(ContextType.Domain, {ADDomain}, {ADContainer});
var group = GroupPrincipal.FindByIdentity(context, IdentityType.Name, {AD_GROUP_NAME});
var user = UserPrincipal.FindByIdentity(context, {login});
bool result = user.IsMemberOf(group);

Ensoul

Answer 13

If you want to check the user groups membership including the nested groups which is indirectly linked to the user parent group you can try use the "tokenGroups" properties as below:

Using System.DirectoryServices

 public static bool IsMemberOfGroupsToCheck(string DomainServer, string LoginID, string LoginPassword)
        {
            string UserDN = "CN=John.Doe-A,OU=Administration Accounts,OU=User Directory,DC=ABC,DC=com"
            string ADGroupsDNToCheck = "CN=ADGroupTocheck,OU=Administration Groups,OU=Group Directory,DC=ABC,DC=com";

            byte[] sid, parentSID;
            bool check = false;
            DirectoryEntry parentEntry;
            DirectoryEntry basechildEntry;
            string octetSID;

                basechildEntry = new DirectoryEntry("LDAP://" + DomainServer + "/" + UserDN, LoginID, LoginPassword);
                basechildEntry.RefreshCache(new String[] { "tokenGroups" });

                parentEntry = new DirectoryEntry("LDAP://" + DomainServer + "/" + ADGroupsDNToCheck, LoginID, LoginPassword);
                parentSID = (byte[])parentEntry.Properties["objectSID"].Value;
                octetSID = ConvertToOctetString(parentSID, false, false);

                foreach(Object GroupSid in basechildEntry.Properties["tokenGroups"])
                {
                    sid = (byte[])GroupSid;
                    if (ConvertToOctetString(sid,false,false) == octetSID)
                    {
                        check = true;
                        break;
                    }
                }

                basechildEntry.Dispose();
                parentEntry.Dispose();

                return check;
        }

Hydrous

Answer 14

How to check user is in AD member and specific AD group member

//This Reference and DLL must be attach in your project         
//using System.DirectoryServices.AccountManagement;        


         public bool IsAuthenticated(string username, string pwd)
        {

            using (PrincipalContext pc = new PrincipalContext(ContextType.Domain, "xxx.com"))   // Your Domain Name
            {
                if (pc.ValidateCredentials(username, password))  //User and Password is OK for Active Directory 
                {
                    UserPrincipal user = UserPrincipal.FindByIdentity(pc, username);  //Get User Active Directory Information Details
                    if (user != null)
                    {

                        var groups = user.GetAuthorizationGroups();   // Get User Authorized Active Directory Groups
                        foreach (GroupPrincipal group in groups)
                        {
                            if (group.Name.Equals("SpecificActiveDirectoryGroupName"))  //Check if user specific group members
                            { 
                                return true;
                            }

                        }
                    }
                }
            }
            return false;
        }

Stets

Answer 15

This should work in .NET 3.5+

// using System.DirectoryServices.AccountManagement;
public static bool IsUserMemberOfGroup(string username, string group)
{
    using (var ctx = new PrincipalContext(ContextType.Domain))
    using (var usr = UserPrincipal.FindByIdentity(ctx, username))
        return usr.IsMemberOf(ctx, IdentityType.Name, group);
}

This is similar to a lot of answers here, but this:

• only finds the user, then checks if the user is a member of a group using just its name (doesn't need to find the Group or iterate over the users/groups)
• Disposes the objects (using usings)

Rebellion