Using ASP.NET Identity with an Int for a primary key.

BaseController.cs

using System;
using System.Security.Claims;
using System.Web.Mvc;
using Vigil.Data;

namespace Vigil.Web.Controllers
{
    public abstract class BaseController : Controller, IDisposable
    {
        public VigilClaimsPrincipal CurrentUser
        {
            get { return new VigilClaimsPrincipal((ClaimsPrincipal)this.User); }
        }
        protected readonly IVigilContext VigilContext = new VigilContext();

        public BaseController() { }

        protected override void Dispose(bool disposing)
        {
            if (disposing && VigilContext != null)
                VigilContext.Dispose();
            base.Dispose(disposing);
        }
    }
}

VigilAuthentication.cs

using System.Data.Entity;
using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.EntityFramework;
using Vigil.Data;
using Vigil.Data.System;

namespace Vigil.Web
{
    public interface IVigilUserStore : IUserStore<VigilUser, int> { }

    public class VigilUserStore : UserStore<VigilUser, VigilRole, int, VigilUserLogin, VigilUserRole, VigilUserClaim>, IVigilUserStore
    {
        public VigilUserStore() : base(new VigilContext()) { }
        public VigilUserStore(DbContext context) : base(context) { }
    }

    public class VigilUserManager : UserManager<VigilUser, int>
    {
        public VigilUserManager() : this(new VigilUserStore(new VigilContext())) { }
        public VigilUserManager(IVigilUserStore store) : base(store) { }
    }
}

VigilClaimsPrincipal.cs

using System;
using System.Security.Claims;
using Vigil.Data;
using Vigil.Data.System;

namespace Vigil.Web
{
    public class VigilClaimsPrincipal : ClaimsPrincipal
    {
        public VigilClaimsPrincipal(ClaimsPrincipal principal) : base(principal) { }

        public int UserId
        {
            get { return Int32.Parse(this.FindFirst(ClaimTypes.Sid).Value); }
        }

        public VigilUser VigilUser
        {
            get { return (new VigilContext()).Set<VigilUser>().Find(UserId); }
        }
    }
}

VigilContext.cs

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Data.Entity.ModelConfiguration.Conventions;
using System.Data.Entity.Validation;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNet.Identity.EntityFramework;
using Vigil.Data.System;

namespace Vigil.Data
{
    public interface IVigilContext : IDisposable
    {
        DbChangeTracker ChangeTracker { get; }
        DbContextConfiguration Configuration { get; }
        Database Database { get; }
        DbEntityEntry Entry(object entity);
        DbEntityEntry<TEntity> Entry<TEntity>(TEntity entity) where TEntity : class;
        IEnumerable<DbEntityValidationResult> GetValidationErrors();
        int SaveChanges();
        Task<int> SaveChangesAsync();
        Task<int> SaveChangesAsync(CancellationToken cancellationToken);
        DbSet<TEntity> Set<TEntity>() where TEntity : class;
        DbSet Set(Type entityType);
    }
    public class VigilContext : IdentityDbContext<VigilUser, VigilRole, int, VigilUserLogin, VigilUserRole, VigilUserClaim>, IVigilContext
    {
        public VigilContext()
            : base("VigilDb")
        {
            Database.SetInitializer<VigilContext>(new VigilDbInitializer());
        }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.HasDefaultSchema("vigil");
            modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
        }
    }
}

VigilIdentity.cs

using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.EntityFramework;

namespace Vigil.Data.System
{
    public class VigilUser : IdentityUser<int, VigilUserLogin, VigilUserRole, VigilUserClaim>, IUser<int>
    {
    }
    public class VigilRole : IdentityRole<int, VigilUserRole>, IRole<int>
    {
    }
    public class VigilUserRole : IdentityUserRole<int>
    {
    }
    public class VigilUserLogin : IdentityUserLogin<int>
    {
    }
    public class VigilUserClaim : IdentityUserClaim<int>
    {
    }
}