LInkedIn oAuth2 request token 400 Bad Request

问题

I am fighting second day with LinkedIN API , each time I am trying to get a token , I am getting 400 Bad Request.

Here is my code , maybe someone can help with this ?

public void RequestAuthentication(System.Web.HttpContextBase context, System.Uri returnUrl)
{
    string url = String.Format("https://www.linkedin.com/uas/oauth2/authorization?response_type=code" +
                 "&client_id={0}" +
                 "&scope={1}" +
                 "&state={3}" +
                 "&redirect_uri={2}",this._consumerKey,_scope,HttpUtility.UrlEncode(returnUrl.ToString()),Guid.NewGuid().ToString());
    context.Response.Redirect(url);
}

public AuthenticationResult VerifyAuthentication(System.Web.HttpContextBase context)
{
    //TODO: check CSRF
    string code = context.Request.QueryString["code"];

    string rawUrl = context.Request.Url.OriginalString;
    //From this we need to remove code portion
    rawUrl = Regex.Replace(rawUrl, "&code=[^&]*", "");

    string authUrl = "https://www.linkedin.com/uas/oauth2/accessToken";
    string postData = String.Format("grant_type=authorization_code&code={0}&redirect_uri={1}&client_id={2}&client_secret={3}", code,HttpUtility.UrlEncode(context.Request.QueryString["ReturnUrl"]), _consumerKey, _consumerSecret);

    //WebClient client = new WebClient();
    //var getReq =  client.DownloadString(authUrl + "?" + postData);

    HttpWebRequest webRequest = WebRequest.Create(authUrl + "?" + postData) as HttpWebRequest;
    webRequest.Method = "POST";

    //This "application/x-www-form-urlencoded"; line is important
    webRequest.ContentType = "application/x-www-form-urlencoded";

    webRequest.ContentLength = postData.Length;

    StreamWriter requestWriter = new StreamWriter(webRequest.GetRequestStream());
    requestWriter.Write(postData);
    requestWriter.Close();

    StreamReader responseReader = new StreamReader(webRequest.GetResponse().GetResponseStream());
}

Any thought ? Maybe someone solved similar in past ?

回答1:

You have to use the same redirect_uri in both

public void RequestAuthentication(System.Web.HttpContextBase context, System.Uri returnUrl)

And

public AuthenticationResult VerifyAuthentication(System.Web.HttpContextBase context)

function. But in your code redirect_uri of first function HttpUtility.UrlEncode(returnUrl.ToString()) and second function HttpUtility.UrlEncode(context.Request.QueryString["ReturnUrl"]) are not same (I think). So make sure you have fix this problem. You code may be worked.

回答2:

I just debugged this, here's some of the things I tried before it was successful. I'm not sure which one made it correct, so I'll put them all down just in case you need somewhere to start:

HTTP protocol 1.1
Add a content-type: application/x-www-form-urlencoded header
Do not refresh the response from the authorization code return page; the code in the URL parameter ($_GET['code'] in PHP) apparently can't be re-used (another answer says it expires every 20 seconds)
- To put it another way, don't try to re-use or cache the authorization code, flow it directly into the access token request ASAP
Do try to use another application (like SoapUI or Fiddlr) to hit the endpoint to show it is working, and to see some headers more clearly
- That being said, looking at the response headers (not just the response code) can be helpful
Sending the data as POST content not as a URL parameter

Note that a 400 error indicates a malformed request (400 BAD request HTTP error code meaning?) not a missing resource (404) which can also be a gotcha if you're thinking too fast.

来源：https://stackoverflow.com/questions/17027589/linkedin-oauth2-request-token-400-bad-request

标签

asp.net-mvc