public override bool ValidateUser(string username, string password)
        {
            bool isAuth = false;

            if (GenUtil.IsNull(username) || GenUtil.IsNull(password))
                return isAuth;
            else
            {
                SPSecurity.RunWithElevatedPrivileges(delegate()
                {

                    var dbUser = db.CustomDbUsersLists.Where(x => x.username.Trim().ToLower() == username.Trim().ToLower()).FirstOrDefault();

                    if (dbUser != null)
                        if (dbUser.password == password) // case sensitive
                            isAuth = true;

                });
            }

            return isAuth; // isAuth is true in debug
        }

class CustomDbUsersRP : RoleProvider
  {

    private CustomDbUsersContextDataContext db = new CustomDbUsersContextDataContext(@"Data Source=MYLOCALSERVERSharePoint;Initial Catalog=CustomDbUsers;Integrated Security=True;Enlist=False;Pooling=True;Min Pool Size=0;Max Pool Size=100;Connect Timeout=15");

    private string theRoleName = "DynamicAdmins";

    public override string[] GetUsersInRole(string roleName)
    {
        if (roleName.Trim().ToLower() != theRoleName.Trim().ToLower())
            return new string[] { };
        else
        {
            string[] users = new string[] { };

            SPSecurity.RunWithElevatedPrivileges(delegate()
            {

                users = db.CustomDbUsersLists.Where(x => x.isadmin == 1).Select(x => x.username).ToArray<string>();

            });

            return users;

        }
    }

    public override bool IsUserInRole(string username, string roleName)
    {
        if (roleName.Trim().ToLower() != theRoleName.Trim().ToLower() ||
            GenUtil.IsNull(username))
            return false;
        else
        {

            bool ret = false;

            SPSecurity.RunWithElevatedPrivileges(delegate()
            {
                if (db.CustomDbUsersLists.Where(x =>
                        x.isadmin == 1 &&
                        x.username.Trim().ToLower() == username.Trim().ToLower())
                        .Any())
                    ret = true;
            });

            return ret;

        }
    }

    public override string[] GetAllRoles()
    {
        return new string[] { theRoleName };
    }

    public override string[] FindUsersInRole(string roleName, string usernameToMatch)
    {
        if (roleName.Trim().ToLower() != theRoleName.Trim().ToLower() ||
            GenUtil.IsNull(usernameToMatch))
            return new string[] { };
        else
        {
            string[] users = new string[] { };

            SPSecurity.RunWithElevatedPrivileges(delegate()
            {

                users = db.CustomDbUsersLists.Where(x =>
                            x.isadmin == 1 &&
                            x.username.Trim().ToLower() == usernameToMatch.Trim().ToLower())
                            .Select(x => x.username).ToArray<string>();

            });

            return users;

        }
    }

    public override string[] GetRolesForUser(string username)
    {
        if (GenUtil.IsNull(username))
            return new string[] { };
        else
        {
            bool isAdmin = false;

            SPSecurity.RunWithElevatedPrivileges(delegate()
            {
                if (db.CustomDbUsersLists.Where(x =>
                        x.isadmin == 1 &&
                        x.username.Trim().ToLower() == username.Trim().ToLower())
                        .Any())
                    isAdmin = true;
            });

            if (isAdmin)
                return new string[] { theRoleName };
            else
                return new string[] { };

        }
    }

    public override bool RoleExists(string roleName)
    {
        return roleName.Trim().ToLower() == theRoleName.Trim().ToLower();
    }

    #region "NOT IMPLEMENTED"

    public override void AddUsersToRoles(string[] usernames, string[] roleNames)
    {
        throw new NotImplementedException();
    }

    public override string ApplicationName
    {
        get
        {
            throw new NotImplementedException();
        }
        set
        {
            throw new NotImplementedException();
        }
    }

    public override void CreateRole(string roleName)
    {
        throw new NotImplementedException();
    }

    public override bool DeleteRole(string roleName, bool throwOnPopulatedRole)
    {
        throw new NotImplementedException();
    }

    public override void RemoveUsersFromRoles(string[] usernames, string[] roleNames)
    {
        throw new NotImplementedException();
    }

    #endregion

}

 }

new string[] { theRoleName };