Sitecore virtual user name | Pattern

Question

I have the following understanding:

1. If an unauthenticated user visits a Sitecore site virtual user is created.

2. The name for the virtual user is a guid.

I want to understand whether it is possible that such a virtual user has either only letters or digits in the name.

Please correct me if I my understanding is wrong.

Answer 1

I assume you are talking about virtual users: https://doc.sitecore.com/xp/en/developers/92/sitecore-experience-manager/configure-federated-authentication.html#configure-virtual-and-persistent-users

I get the same result when I login with a virtual user. If the user does not exist a unique username is generated. This is done in the following class:

Sitecore.Owin.Authentication.Services.DefaultExternalUserBuilder.CreateUniqueUserName

This is what the decompiled class looks like for Sitecore 10.2:

using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.Owin;
using Sitecore.Diagnostics;
using Sitecore.Owin.Authentication.Configuration;
using Sitecore.Owin.Authentication.Identity;
using Sitecore.SecurityModel.Cryptography;
using System;
using System.Text;

namespace Sitecore.Owin.Authentication.Services
{
  public class DefaultExternalUserBuilder : ExternalUserBuilder
  {
    private readonly IHashEncryption _hashEncryption;

    public DefaultExternalUserBuilder(ApplicationUserFactory applicationUserFactory, IHashEncryption hashEncryption)
    {
      Assert.ArgumentNotNull((object) applicationUserFactory, nameof (applicationUserFactory));
      Assert.ArgumentNotNull((object) hashEncryption, nameof (hashEncryption));
      this._hashEncryption = hashEncryption;
      this.ApplicationUserFactory = applicationUserFactory;
    }

    public bool IsPersistentUser { get; set; }

    protected ApplicationUserFactory ApplicationUserFactory { get; }

    public override ApplicationUser BuildUser(UserManager<ApplicationUser> userManager, ExternalLoginInfo externalLoginInfo)
    {
      ApplicationUser user = this.ApplicationUserFactory.CreateUser(this.CreateUniqueUserName(userManager, externalLoginInfo));
      user.IsVirtual = !this.IsPersistentUser;
      user.Email = externalLoginInfo.Email;
      return user;
    }

    protected virtual string CreateUniqueUserName(UserManager<ApplicationUser> userManager, ExternalLoginInfo externalLoginInfo)
    {
      Assert.ArgumentNotNull((object) userManager, nameof (userManager));
      Assert.ArgumentNotNull((object) externalLoginInfo, nameof (externalLoginInfo));
      IdentityProvider identityProvider = this.FederatedAuthenticationConfiguration.GetIdentityProvider(externalLoginInfo.ExternalIdentity);
      if (identityProvider == null)
        throw new InvalidOperationException("Unable to retrieve an identity provider for the given identity");
      string domain = identityProvider.Domain;
      string s = externalLoginInfo.Login.LoginProvider + externalLoginInfo.Login.ProviderKey;
      string userName;
      do
      {
        s += "$";
        string str1 = System.Convert.ToBase64String(this._hashEncryption.ComputeHash(Encoding.ASCII.GetBytes(s))).Trim('=').Replace("/", string.Empty).Replace("+", string.Empty);
        string str2 = str1.Substring(0, Math.Min(str1.Length, 10));
        userName = domain + "\\" + str2;
      }
      while (userManager.FindByName<ApplicationUser, string>(userName) != null);
      return userName;
    }
  }
}

As you can see the result of the CreateUniqueUserName method will return the domain with the unique username. The username is also 10 characters long.

For example I got this username after login: extranet\ahLpHAJFUy.

If you want to change this you can override the DefaultExternalUserBuilder pipeline. If you search for Sitecore.Owin.Authentication.Services.DefaultExternalUserBuilder in /sitecore/admin/showconfig.aspx you should be able to find it. You can do a config transform to override it or change it manually in \App_Config\Sitecore\Owin.Authentication\Sitecore.Owin.Authentication.config.

You can probably make a copy of the decompiled class I posted here and make your changes in that. So it should be possible to change it.