c# - ASP.Net Identity 2 - 来自 OAuthAuthorizationServerProvider 的自定义响应

Question

这个问题是我上一个问题的延续:ASP.Net Identity 2 login using password from SMS - not using two-factor authentication

我构建了自定义 OAuthAuthorizationServerProvider 以支持自定义 grant_type。
我的想法是创建 sms 的 grant_type，这将允许用户生成一次性访问代码，该代码将发送到他的手机，然后在使用 grant_type 密码发送请求时作为密码用户。

现在，在生成、存储并通过 SMS 发送该密码后，我想返回自定义响应，而不是来 self 的 GrantCustomExtension 的 token 。

public override async Task GrantCustomExtension(OAuthGrantCustomExtensionContext context)
{
    const string allowedOrigin = "*";
    context.OwinContext.Response.Headers.Add("Access-Control-Allow-Origin", new[] {allowedOrigin});

    if (context.GrantType != "sms")
    {
        context.SetError("invalid_grant", "unsupported grant_type");
        return;
    }

    var userName = context.Parameters.Get("username");

    if (userName == null)
    {
        context.SetError("invalid_grant", "username is required");
        return;
    }

    var userManager = context.OwinContext.GetUserManager<ApplicationUserManager>();

    ApplicationUser user = await userManager.FindByNameAsync(userName);

    if (user == null)
    {
        context.SetError("invalid_grant", "user not found");
        return;
    }

    var generator = new TotpSecurityStampBasedTokenProvider<ApplicationUser, string>();
    await userManager.UpdateSecurityStampAsync(user.Id);
    var accessCode = await generator.GenerateAsync("SMS", userManager, user);

    var accessCodeExpirationTime = TimeSpan.FromMinutes(5);

    var result = await userManager.AddAccessCode(user, accessCode, accessCodeExpirationTime);


    if(result.Succeeded)
    {
        Debug.WriteLine("Login code:"+accessCode);
        //here I'll send login code to user phone via SMS
    }


    //return 200 (OK)
    //with content type="application/json; charset=utf-8"
    //and custom json content {"message":"code send","expires_in":300}

    //skip part below

    ClaimsIdentity oAuthIdentity = await user.GenerateUserIdentityAsync(userManager, "SMS");

    var ticket = new AuthenticationTicket(oAuthIdentity, null);

    context.Validated(ticket);

}

如何停止生成 token 并从 OAuthAuthorizationServerProvider 返回自定义响应？

我知道两种方法:TokenEndpoint、TokenEndpointResponse，但我想覆盖整个响应，而不仅仅是 token 。

编辑:
现在，我正在使用以下代码在 GrantCustomExtension 中创建临时 ClaimsIdentity:

var ci = new ClaimsIdentity();
ci.AddClaim(new Claim("message","send"));
ci.AddClaim(new Claim("expires_in", accessCodeExpirationTime.TotalSeconds.ToString(CultureInfo.InvariantCulture)));
context.Validated(ci);

我正在覆盖 TokenEndpointResponse:

public override Task TokenEndpointResponse(OAuthTokenEndpointResponseContext context)
{
    if (context.TokenEndpointRequest.GrantType != "sms") return base.TokenEndpointResponse(context);
    //clear response containing temporary token.
    HttpContext.Current.Response.SuppressContent = true;
    return Task.FromResult<object>(null);
}

这有两个问题:当调用 context.Validated(ci); 时，我说这是一个有效的用户，但我想响应我已发送访问代码的信息通过短信。HttpContext.Current.Response.SuppressContent = true; 清除响应，但我想返回一些内容而不是空响应。

Answer 1

这更像是一种解决方法，而不是最终解决方案，但我相信这是解决问题的最可靠方法，无需重写默认 OAuthAuthorizationServerProvider 实现中的大量代码。

方法很简单:使用 Owin 中间件捕获 token 请求，并在发送 SMS 时覆盖响应。

[评论后编辑] 修复了代码以允许根据此答案缓冲和更改响应主体 https://stackoverflow.com/a/36414238/965722

在您的 Startup.cs 文件中:

public void Configuration(IAppBuilder app)
{
    var tokenPath = new PathString("/Token"); //the same path defined in OAuthOptions.TokenEndpointPath

    app.Use(async (c, n) =>
    {
        //check if the request was for the token endpoint
        if (c.Request.Path == tokenPath)
        {
            var buffer = new MemoryStream();
            var body = c.Response.Body;
            c.Response.Body = buffer; // we'll buffer the response, so we may change it if needed

            await n.Invoke(); //invoke next middleware (auth)

            //check if we sent a SMS
            if (c.Get<bool>("sms_grant:sent"))
            {
                var json = JsonConvert.SerializeObject(
                    new
                    {
                        message = "code send",
                        expires_in = 300
                    });

                var bytes = Encoding.UTF8.GetBytes(json);

                buffer.SetLength(0); //change the buffer
                buffer.Write(bytes, 0, bytes.Length);

                //override the response headers
                c.Response.StatusCode = 200;
                c.Response.ContentType = "application/json";
                c.Response.ContentLength = bytes.Length;
            }

            buffer.Position = 0; //reset position
            await buffer.CopyToAsync(body); //copy to real response stream
            c.Response.Body = body; //set again real stream to response body
        }
        else
        {
            await n.Invoke(); //normal behavior
        }
    });

    //other owin middlewares in the pipeline
    //ConfigureAuth(app);

    //app.UseWebApi( .. );
}

在您的自定义授权方法中:

// ...
var result = await userManager.AddAccessCode(user, accessCode, accessCodeExpirationTime);


if(result.Succeeded)
{
    Debug.WriteLine("Login code:"+accessCode);
    //here I'll send login code to user phone via SMS
}

context.OwinContext.Set("sms_grant:sent", true);

//you may validate the user or set an error, doesn't matter anymore
//it will be overwritten
//...