DotNetOpenAuth CTP - Facebook錯誤請求

Question

我正在嘗試使用CTP通過OAuth 2.0與Facebook連接。

我可以得到Facebook的初始請求工作正常，但當它回來時我們打電話：

// Where null will become an HttpRequestInfo object
client.ProcessUserAuthorization(null);

我明白了：

遠程服務器返回錯誤：（400）錯誤請求。

我對初始代碼庫沒有太多幫助; 只是將可選值設置為null（我們仍然在.NET 3.5上）。 任何線索將非常感激。

此外，我想這對安德魯來說更具問題; 是否存在任何此類內容的論壇/博客，或者定期更新的任何地方？ 了解一些事情會很棒：

1. 使用OAuth 2.0計划發布DotNetOpenAuth的日期
2. .NET 4.0是否是先決條件

無論如何，任何建議都是最受歡迎的。

Answer 1

在遇到這個問題后，我編寫了自己的代碼進行授權，並獲取用戶詳細信息。 另一種方法是使用Facebook C＃SDK 。 作為其他任何想要自己做的人的首發，我就是這樣做的。 請注意我沒有查看錯誤案例。

首先， 閱讀facebooks doc如何工作（它相當簡單！）

我這樣消耗它：

private static readonly FacebookClient facebookClient = new FacebookClient();
public ActionResult LoginWithFacebook()
{
    var result = facebookClient.Authorize();
    if (result == FacebookAuthorisationResult.RequestingCode)
    {
        //The client will have already done a Response.Redirect
        return View();
    } else if (result == FacebookAuthorisationResult.Authorized)
    {
        var user = facebookClient.GetCurrentUser();
    }
    return Redirect("/");
}

和客戶端代碼：

using System;
using System.IO;
using System.Net;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;
using System.Text;
using System.Web;

namespace Web.Services
{
    public enum FacebookAuthorisationResult
    {
        Denied,
        Authorized,
        RequestingCode
    }
    public class FacebookClient
    {
        private const String SESSION_NAME_TOKEN = "UserFacebookToken";
        public FacebookClient()
        {
            TokenEndpoint = new Uri("https://graph.facebook.com/oauth/access_token");
            AuthorizationEndpoint = new Uri("https://graph.facebook.com/oauth/authorize");
            MeGraphEndpoint = new Uri("https://graph.facebook.com/me");
            ClientIdentifier = "xxxxxxxxxxxxxxxxxx";
            Secret = "xxxxxxxxxxxx";
            LocalSubDomain = "local.xxxxxxx.com";
        }

        public Uri TokenEndpoint { get; set; }
        public Uri AuthorizationEndpoint { get; set; }
        public Uri MeGraphEndpoint { get; set; }
        public String Secret { get; set; }
        public String ClientIdentifier { get; set; }
        private String LocalSubDomain { get; set; }


        public FacebookAuthorisationResult Authorize()
        {
            var errorReason = HttpContext.Current.Request.Params["error_reason"];
            var userDenied = errorReason != null;
            if (userDenied)
                return FacebookAuthorisationResult.Denied;
            var verificationCode = HttpContext.Current.Request.Params["code"];
            var redirectUrl = GetResponseUrl(HttpContext.Current.Request.Url);
            var needToGetVerificationCode = verificationCode == null;
            if (needToGetVerificationCode)
            {
                var url = AuthorizationEndpoint + "?" +
                          "client_id=" + ClientIdentifier + "&" +
                          "redirect_uri=" + redirectUrl;
                HttpContext.Current.Response.Redirect(url);
                return FacebookAuthorisationResult.RequestingCode;
            }
            var token = ExchangeCodeForToken(verificationCode, redirectUrl);
            HttpContext.Current.Session[SESSION_NAME_TOKEN] = token;
            return FacebookAuthorisationResult.Authorized;
        }
        public Boolean IsCurrentUserAuthorized()
        {
            return HttpContext.Current.Session[SESSION_NAME_TOKEN] != null;
        }
        public FacebookGraph GetCurrentUser()
        {
            var token = HttpContext.Current.Session[SESSION_NAME_TOKEN];
            if (token == null)
                return null;
            var url = MeGraphEndpoint + "?" +
                      "access_token=" + token;
            var request = WebRequest.CreateDefault(new Uri(url));
            using (var response = request.GetResponse())
            {
                using (var responseStream = response.GetResponseStream())
                {
                    using (var responseReader = new StreamReader(responseStream))
                    {
                        var responseText = responseReader.ReadToEnd();
                        var user =  FacebookGraph.Deserialize(responseText);
                        return user;
                    }
                }
            }
        }
        private String ExchangeCodeForToken(String code, Uri redirectUrl)
        {
            var url = TokenEndpoint + "?" +
                      "client_id=" + ClientIdentifier + "&" +
                      "redirect_uri=" + redirectUrl + "&" +
                      "client_secret=" + Secret + "&" +
                      "code=" + code;
            var request = WebRequest.CreateDefault(new Uri(url));
            using (var response = request.GetResponse())
            {
                using (var responseStream = response.GetResponseStream())
                {
                    using (var responseReader = new StreamReader(responseStream))
                    {
                        var responseText = responseReader.ReadToEnd();
                        var token = responseText.Replace("access_token=", "");
                        return token;
                    }
                }
            }
        }
        private Uri GetResponseUrl(Uri url)
        {
            var urlAsString = url.ToString();
            var doesUrlContainQuestionMark = urlAsString.Contains("?");
            if (doesUrlContainQuestionMark)
            {
                // Remove any parameters. Apparently Facebook does not support state: http://forum.developers.facebook.net/viewtopic.php?pid=255231
                // If you do not do this, you will get 'Error validating verification code'
                urlAsString = urlAsString.Substring(0, urlAsString.IndexOf("?"));
            }
            var replaceLocalhostWithSubdomain = url.Host == "localhost";
            if (!replaceLocalhostWithSubdomain)
                return new Uri(urlAsString);
            // Facebook does not like localhost, you can only use the configured url. To get around this, log into facebook
            // and set your Site Domain setting, ie happycow.com. 
            // Next edit C:\Windows\System32\drivers\etc\hosts, adding the line: 
            // 127.0.0.1       local.happycow.cow
            // And lastly, set LocalSubDomain to local.happycow.cow
            urlAsString = urlAsString.Replace("localhost", LocalSubDomain);
            return new Uri(urlAsString);
        }
    }
    [DataContract]
    public class FacebookGraph
    {
        private static DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(typeof(FacebookGraph));
            // Note: Changed from int32 to string based on Antonin Jelinek advise of an overflow
        [DataMember(Name = "id")]
        public string Id { get; set; }

        [DataMember(Name = "name")]
        public string Name { get; set; }

        [DataMember(Name = "first_name")]
        public string FirstName { get; set; }

        [DataMember(Name = "last_name")]
        public string LastName { get; set; }

        [DataMember(Name = "link")]
        public Uri Link { get; set; }

        [DataMember(Name = "birthday")]
        public string Birthday { get; set; }

        public static FacebookGraph Deserialize(string json)
        {
            if (String.IsNullOrEmpty(json))
            {
                throw new ArgumentNullException("json");
            }

            return Deserialize(new MemoryStream(Encoding.UTF8.GetBytes(json)));
        }

        public static FacebookGraph Deserialize(Stream jsonStream)
        {
            if (jsonStream == null)
            {
                throw new ArgumentNullException("jsonStream");
            }

            return (FacebookGraph)jsonSerializer.ReadObject(jsonStream);
        }
    }


}

Answer 2

Iain的解決方案終於讓我的東西與之合作。

未來的實施者有一個注意事項 - 似乎Facebook ID屬性現在超過了Int32類型的容量。 你可能需要在FacebookGraph類中更改它，我使用了純字符串。

謝謝Iain，你的代碼真的幫助了我！

Answer 3

在搞砸了DotNetOpenAuth的升級很長一段時間並且沒有經歷任何連接到Facebook的運氣之后，我也整理了一些代碼以支持從我的ASP.NET MVC應用程序中登錄Facebook。

首先，這樣的代碼應該放在控制器的某個地方。

// You call this action to initiate the process with Facebook
public ActionResult FacebookLogIn()
{
    return CreateFacebookClient().RequestAuthorisation();
}

// Facebook will call you back here
public ActionResult FacebookAuthorisationResponse()
{
    var facebookClient = CreateFacebookClient();
    var authorisationResponse = facebookClient.HandleAuthorisationResponse();

    if (authorisationResponse.IsSuccess)
    {
        var accessToken = authorisationResponse.AccessToken;

        // TODO do whatever you want to do with your access token here

        return Redirect("SomeUrl");
    }

    // TODO handle the error somehow
    return Content(authorisationResponse.ErrorMessage);
}

private FacebookClient CreateFacebookClient()
{
    const string clientId = "xxxxxxxxxxxxxxx";
    const string appSecret = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";

    var redirectUrl = Url.Action("FacebookAuthorisationResponse", null, null, "http");

    return new FacebookClient(clientId, appSecret, redirectUrl);
}

這幾乎就是你需要對代碼做的所有事情。 獲得該訪問令牌后，您可以執行以下操作：

// Get basic information for this user
var basicInfoUrl = string.Format("https://graph.facebook.com/me?access_token={0}", Uri.EscapeDataString(accessToken.TokenString));
var json = new WebClient().DownloadString(basicInfoUrl);

支持上面相對簡單的東西的代碼就在這里。 您可以將所有這些轉儲到項目的文件中：

// Drew Noakes, http://drewnoakes.com
// Created 08/08/2012 22:41

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Web;
using System.Web.Mvc;

namespace DrewNoakes.Facebook.Mvc
{
    public sealed class FacebookClient
    {
        private readonly string _clientId;
        private readonly string _appSecret;
        private readonly string _authorisationResponseUrl;

        public IFacebookClientStateManager StateManager { get; set; }

        public FacebookClient(string clientId, string appSecret, string authorisationResponseUrl)
        {
            _clientId = clientId;
            _appSecret = appSecret;
            _authorisationResponseUrl = authorisationResponseUrl;

            StateManager = MemoryStateManager.Instance;
        }

        public ActionResult RequestAuthorisation(string[] permissions = null)
        {
            // First step is to redirect the visitor's browser to Facebook

            var state = StateManager.GetState();

            var url = string.Format("https://www.facebook.com/dialog/oauth?client_id={0}&redirect_uri={1}&scope={2}&state={3}",
                _clientId, Uri.EscapeDataString(_authorisationResponseUrl), permissions == null ? string.Empty : string.Join(",", permissions), state);

            return new RedirectResult(url, permanent: false);
        }

        public AuthorisationResponse HandleAuthorisationResponse()
        {
            var queryString = HttpContext.Current.Request.QueryString;

            // Ensure returned state is expected
            if (!StateManager.IsValidState(queryString["state"]))
                return AuthorisationResponse.Error("Invalid state");

            // TODO handle case where user declined: YOUR_REDIRECT_URI?error_reason=user_denied&error=access_denied&error_description=The+user+denied+your+request.&state=YOUR_STATE_VALUE

            var code = queryString["code"];
            var url = string.Format("https://graph.facebook.com/oauth/access_token?client_id={0}&redirect_uri={1}&code={3}&client_secret={2}",
                _clientId, Uri.EscapeDataString(_authorisationResponseUrl), _appSecret, Uri.EscapeDataString(code));

            var client = new WebClient { Proxy = null };
            var responseBody = client.DownloadString(url);

            // HTTP 200: access_token=USER_ACCESS_TOKEN&expires=NUMBER_OF_SECONDS_UNTIL_TOKEN_EXPIRES
            // HTTP 400: TODO handle JSON error reponse: { "error": { "type": "OAuthException", "message": "Error validating verification code." } }

            var response = HttpUtility.ParseQueryString(responseBody);
            var accessToken = response["access_token"];
            var expiresSecondsString = response["expires"];

            int expiresSeconds;
            if (!int.TryParse(expiresSecondsString, out expiresSeconds))
                return AuthorisationResponse.Error("Unable to parse expiration time");
            var expiresAtUtc = DateTime.UtcNow.AddSeconds(expiresSeconds);

            return AuthorisationResponse.Success(accessToken, expiresAtUtc);
        }
    }

    public class AuthorisationResponse
    {
        public bool IsSuccess { get; private set; }
        public AccessToken AccessToken { get; private set; }
        public string ErrorMessage { get; private set; }

        private AuthorisationResponse() { }

        public static AuthorisationResponse Error(string errorMessage)
        {
            return new AuthorisationResponse { IsSuccess = false, ErrorMessage = errorMessage };
        }

        public static AuthorisationResponse Success(string accessToken, DateTime expiresAtUtc)
        {
            return new AuthorisationResponse { IsSuccess = true, AccessToken = new AccessToken(accessToken, expiresAtUtc) };
        }
    }

    public struct AccessToken
    {
        public string TokenString { get; private set; }
        public DateTime ExpiresAtUtc { get; private set; }

        public AccessToken(string tokenString, DateTime expiresAtUtc)
            : this()
        {
            if (tokenString == null)
                throw new ArgumentNullException("tokenString");
            TokenString = tokenString;
            ExpiresAtUtc = expiresAtUtc;
        }
    }

    public interface IFacebookClientStateManager
    {
        string GetState();

        bool IsValidState(string state);
    }

    /// <summary>
    /// The default implementation of <see cref="IFacebookClientStateManager"/>.
    /// </summary>
    public sealed class MemoryStateManager : IFacebookClientStateManager
    {
        private static readonly IFacebookClientStateManager _instance = new MemoryStateManager();

        public static IFacebookClientStateManager Instance
        {
            get { return _instance; }
        }

        private readonly Dictionary<string, DateTime> _stateTimes = new Dictionary<string, DateTime>();

        public string GetState()
        {
            var state = Guid.NewGuid().ToString("N");
            _stateTimes[state] = DateTime.UtcNow;
            return state;
        }

        public bool IsValidState(string state)
        {
            var isValid = _stateTimes.Remove(state);

            // Remove any keys that have not been accessed within a given period
            var staleKeys = _stateTimes.Where(pair => pair.Value < DateTime.UtcNow.AddMinutes(-30)).Select(pair => pair.Key).ToList();

            foreach (var staleKey in staleKeys)
                _stateTimes.Remove(staleKey);

            return isValid;
        }
    }
}

我今晚很快就把它扔到了一起，但如果發現問題，我會稍后再回來修補它。 它現在在我的網站上運行得非常好。

有一些與強大的錯誤響應處理相關的TODO。

Answer 4

當我使用WebServerClient的PrepareRequestUserAuthorization()的returnTo參數時，我一直在間歇地遇到同樣的問題。 只有某些returnTo URI會遇到問題...我傳入的URI有一個Base64組件。 其中一些在其中包含=。 如果我對這些URL進行URL編碼，我會從本地服務器收到“從客戶端檢測到潛在危險的Request.Path值（％）”錯誤。

直到我找到一個更好的解決方案，我才會在傳遞之前對字符串進行一些刺激;

localReturnTo = localReturnTo.Replace("=", "_")

然后，當我收到我的回復時，我執行相反的操作;

returnedUri = returnedUri.Replace("_", "=")

它不漂亮。 但它確實解決了我遇到的直接（類似）問題。

Answer 5

我發現編寫自己的實現比使用DNOA花費更少的時間。 這並不是很困難，雖然我還沒有真正對代碼進行徹底的安全檢查; 我想這將是一個重要的警告。

這可能沒那么有用，但我發現只需要每天花一半時間才能完成工作。