我可以从 email 地址而不是 ASP.NET Core 和 DirectoryServices 中的用户名获取用户身份吗？

Question

I have a need for users to be able to enter an email address and after clicking submit, I'd like to get some Active Directory information from the email address entered. Our usernames unfortunately don't follow a single naming convention so I'm unable to reliably guess the username from the email address entered.

I'm fine with looking up information from a username, is there a way of back tracking to an identity from an email address entered using DirectoryServices or something similar?

Thanks,

Edit and some clarifiction:

On the form, it's not the authenticated users email address that I would be looking up, it's the email address that was entered in the form.

    public class ManagerDetails
    {
        public string GetManagersName(string emailAddress)
        {
            PrincipalContext ctx = new PrincipalContext(ContextType.Domain);
            UserPrincipal mgr = UserPrincipal.FindByIdentity(ctx, emailAddress);

            string managersName = mgr.GivenName;

            return managersName;
        }
    }

This piece of code works, but only if the username matches the email address.

For example, this works, Joe.Bloggs@mydomain.com (email) and Joe.Bloggs (domain username).

If it's Joe.Bloggs@mydomain.com (email) and BloggsJ (domain username) it fails.

This is obviously because it's using the email address as the full username but hopefully it explains what I'm trying to achieve.

Answer 1

I'm still refining but this works, it allows me to use directory searcher to get a name from an email address entered.

        public string GetManagersName(string emailAddress)
        {
            string userName = GetManagersUserNameByEmailAddress(emailAddress);

            PrincipalContext ctx = new PrincipalContext(ContextType.Domain);
            UserPrincipal usr = UserPrincipal.FindByIdentity(ctx, userName);

            string managersName = usr.GivenName;

            return managersName;
        }

        private string GetManagersUserNameByEmailAddress(string emailAddress)
        {
            DirectorySearcher adSearcher = new DirectorySearcher();
            adSearcher.Filter = ("mail=" + emailAddress);
            adSearcher.PropertiesToLoad.Add("samaccountname");

            SearchResult result = adSearcher.FindOne();

            DirectoryEntry user = result.GetDirectoryEntry();

            string userName = user.Properties["samaccountname"].Value.ToString();

            return userName;
        }