Adding dynamic claims to a principal

DynamicOrganizationRoleClaimsFactory.cs

public class DynamicOrganizationRoleClaimsFactory : UserClaimsPrincipalFactory<ApplicationUser>
{
    private readonly ApplicationDbContext dbContext;

    public DynamicOrganizationRoleClaimsFactory(UserManager<ApplicationUser> userManager, 
        IOptions<IdentityOptions> optionsAccessor, ApplicationDbContext dbContext) 
        : base(userManager, optionsAccessor)
    {
        this.dbContext = dbContext;
    }

    public override async Task<ClaimsPrincipal> CreateAsync(ApplicationUser user)
    {
        var principal = await base.CreateAsync(user);

        var orgRoleClaims = dbContext.Set<OrganizationMembership>()
            .Where(om => om.UserId == user.Id)
            .Select(om => new Claim($"org_role_{om.Role}".ToLowerInvariant(), om.OrganizationId.ToString()));

        ((ClaimsIdentity) principal.Identity).AddClaims(orgRoleClaims);

        return principal;
    }
}

// at startup
services.AddScoped<IUserClaimsPrincipalFactory<ApplicationUser>, DynamicOrganizationRoleClaimsFactory>();