ASP.net Identity SecurityStampValidator OnValidateIdentity regenerateIdentity参数

Question

任何人都可以解释为什么ApplicationUser该类创建以下帮助函数？

public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<User, int> manager)
{
    // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
    var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
    // Add custom user claims here
    return userIdentity;
}

我能找到它的唯一地方是在Startup.Auth.cs文件中,作为函数的regenerateIdentity回调参数 SecurityStampValidator.OnValidateEntity:

OnValidateIdentity = SecurityStampValidator.OnValidateIdentity<ApplicationUserManager, User, int>(
     validateInterval: TimeSpan.FromSeconds(15),
     regenerateIdentityCallback: (manager, user) => user.GenerateUserIdentityAsync(manager),
     getUserIdCallback: (id) => id.GetUserId<int>())

正如你从助手那里看到的那样,它只是转身并打电话manager.CreatedIdentityAsync.有没有理由他们ApplicationUser用帮助方法"污染"这个类而不是设置OnValidateEntity如下？

OnValidateIdentity = SecurityStampValidator.OnValidateIdentity<ApplicationUserManager, User, int>(
     validateInterval: TimeSpan.FromSeconds(15),
     regenerateIdentityCallback: (manager, user) => manager.CreateIdentityAsync(user, DefaultAuthenticationTypes.ApplicationCookie),
     getUserIdCallback: (id) => id.GetUserId<int>())

Answer 1

*编辑清晰简洁

通过将Identity Generation方法抽象到用户类中,我们可以获得可扩展性.

想象一下,您的应用程序具有多种不同的用户类型,每种用户都可以实现自己的再生逻辑,而无需使用单独的身份验证类型.获取IdentityUser基类的ApplicationUser子类中的helper方法.

public class ApplicationUser : IdentityUser
{      
    public string NickName {get; set; }
    public DateTime BirthDay {get; set;}


    public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser> manager)
    {
        // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
        var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
        // Add custom user claims here
        return userIdentity;
    }
}

我们现在可以将我们的声明分成不同的用户类,而无需修改OWIN身份验证管道,或者仅通过继承基本IdentityUser为每种类型创建新的CookieAuthenticationProvider.

tldr;

它将身份重新生成职责推送到正在重新生成的用户类.类似于工厂方法模式.