Using C#, how do you check if a computer account is disabled in active directory?

Question

How do you check if a computer account is disabled in Active Directory using C#/.NET

Answer 1

If you are using samAcountName or any other Identity field.. it is way simpler to use UserPrincipal.FindByIdentity method. And use the hybrid approach to Leandro López and Deepti. both their approaches are very good.. but very narrowly focused. More details on this flag is available on MSDN

Answer 2

You can easily decode the userAccountControl property by converting your result to an enum.

int userAccountControlValue = 544;
UserAccountControl userAccountControl = (UserAccountControl) userAccountControlValue;

// This gets a comma separated string of the flag names that apply.
string userAccountControlFlagNames = userAccountControl.ToString();

// This is how you test for an individual flag.
bool isNormalAccount = (userAccountControl & UserAccountControl.NORMAL_ACCOUNT) == UserAccountControl.NORMAL_ACCOUNT;
bool isAccountDisabled = (userAccountControl & UserAccountControl.ACCOUNTDISABLE) == UserAccountControl.ACCOUNTDISABLE;
bool isAccountLockedOut = (userAccountControl & UserAccountControl.LOCKOUT) == UserAccountControl.LOCKOUT;

You can also use it to build an LDAP filter:

// To get a user that is disabled.
string ldapFilter = string.Format("(&(objectCategory=person)(objectClass=user)(sAMAccountName={0})(userAccountControl:1.2.840.113556.1.4.803:={1:D}))", accountName, UserAccountControl.ACCOUNTDISABLE)

// To get a user that is not disabled.
string ldapFilter = string.Format("(&(objectCategory=person)(objectClass=user)(sAMAccountName={0})(!(userAccountControl:1.2.840.113556.1.4.803:={1:D})))", accountName, UserAccountControl.ACCOUNTDISABLE)

Also see Active Directory: LDAP Syntax Filters for examples of commonly useful Active Directory LDAP filters.

Here's the enum definition that you want:

/// <summary>
/// Flags that control the behavior of the user account.
/// </summary>
[Flags()]
public enum UserAccountControl : int
{
    /// <summary>
    /// The logon script is executed. 
    ///</summary>
    SCRIPT = 0x00000001,

    /// <summary>
    /// The user account is disabled. 
    ///</summary>
    ACCOUNTDISABLE = 0x00000002,

    /// <summary>
    /// The home directory is required. 
    ///</summary>
    HOMEDIR_REQUIRED = 0x00000008,

    /// <summary>
    /// The account is currently locked out. 
    ///</summary>
    LOCKOUT = 0x00000010,

    /// <summary>
    /// No password is required. 
    ///</summary>
    PASSWD_NOTREQD = 0x00000020,

    /// <summary>
    /// The user cannot change the password. 
    ///</summary>
    /// <remarks>
    /// Note:  You cannot assign the permission settings of PASSWD_CANT_CHANGE by directly modifying the UserAccountControl attribute. 
    /// For more information and a code example that shows how to prevent a user from changing the password, see User Cannot Change Password.
    // </remarks>
    PASSWD_CANT_CHANGE = 0x00000040,

    /// <summary>
    /// The user can send an encrypted password. 
    ///</summary>
    ENCRYPTED_TEXT_PASSWORD_ALLOWED = 0x00000080,

    /// <summary>
    /// This is an account for users whose primary account is in another domain. This account provides user access to this domain, but not 
    /// to any domain that trusts this domain. Also known as a local user account. 
    ///</summary>
    TEMP_DUPLICATE_ACCOUNT = 0x00000100,

    /// <summary>
    /// This is a default account type that represents a typical user. 
    ///</summary>
    NORMAL_ACCOUNT = 0x00000200,

    /// <summary>
    /// This is a permit to trust account for a system domain that trusts other domains. 
    ///</summary>
    INTERDOMAIN_TRUST_ACCOUNT = 0x00000800,

    /// <summary>
    /// This is a computer account for a computer that is a member of this domain. 
    ///</summary>
    WORKSTATION_TRUST_ACCOUNT = 0x00001000,

    /// <summary>
    /// This is a computer account for a system backup domain controller that is a member of this domain. 
    ///</summary>
    SERVER_TRUST_ACCOUNT = 0x00002000,

    /// <summary>
    /// Not used. 
    ///</summary>
    Unused1 = 0x00004000,

    /// <summary>
    /// Not used. 
    ///</summary>
    Unused2 = 0x00008000,

    /// <summary>
    /// The password for this account will never expire. 
    ///</summary>
    DONT_EXPIRE_PASSWD = 0x00010000,

    /// <summary>
    /// This is an MNS logon account. 
    ///</summary>
    MNS_LOGON_ACCOUNT = 0x00020000,

    /// <summary>
    /// The user must log on using a smart card. 
    ///</summary>
    SMARTCARD_REQUIRED = 0x00040000,

    /// <summary>
    /// The service account (user or computer account), under which a service runs, is trusted for Kerberos delegation. Any such service 
    /// can impersonate a client requesting the service. 
    ///</summary>
    TRUSTED_FOR_DELEGATION = 0x00080000,

    /// <summary>
    /// The security context of the user will not be delegated to a service even if the service account is set as trusted for Kerberos delegation. 
    ///</summary>
    NOT_DELEGATED = 0x00100000,

    /// <summary>
    /// Restrict this principal to use only Data Encryption Standard (DES) encryption types for keys. 
    ///</summary>
    USE_DES_KEY_ONLY = 0x00200000,

    /// <summary>
    /// This account does not require Kerberos pre-authentication for logon. 
    ///</summary>
    DONT_REQUIRE_PREAUTH = 0x00400000,

    /// <summary>
    /// The user password has expired. This flag is created by the system using data from the Pwd-Last-Set attribute and the domain policy. 
    ///</summary>
    PASSWORD_EXPIRED = 0x00800000,

    /// <summary>
    /// The account is enabled for delegation. This is a security-sensitive setting; accounts with this option enabled should be strictly 
    /// controlled. This setting enables a service running under the account to assume a client identity and authenticate as that user to 
    /// other remote servers on the network.
    ///</summary>
    TRUSTED_TO_AUTHENTICATE_FOR_DELEGATION = 0x01000000,

    /// <summary>
    /// 
    /// </summary>
    PARTIAL_SECRETS_ACCOUNT = 0x04000000,

    /// <summary>
    /// 
    /// </summary>
    USE_AES_KEYS = 0x08000000
}