The remote server returned an error: (401) Unauthorized - Error

[manimaran....@gmail.com]

Hi 

I am trying to post a new text message in tumblr wall from C# Web Application.. But I'm getting the "The remote server returned an error: (401) Unauthorized." error message when i try to post message.  I'm using the following url (http://api.tumblr.com/v2/blog/upfrontApp.tumblr.com/post) to post a text message. The upfrontApp.tumblr.com is my tumblr  application name.. I'm trying fix this error from last two, three weeks but i can not get a correct solution.. Please help me. Please give me any suggestion or idea.. Your any suggestion or idea will be helping me lot.. I'm waiting for your response. Thanks a lot..

this is my code to post a text message..

url= http://api.tumblr.com/v2/blog/upfrontApp.tumblr.com/post

method = POST or PUT

postData = my test data

public string APIWebRequest(string method, string url, string postData)

        {

            Uri uri = new Uri(url);

            string nonce = this.GenerateNonce();

            string timeStamp = this.GenerateTimeStamp();

            string outUrl, querystring;

            string sig = this.GenerateSignature(uri,

                this.ConsumerKey,

                this.ConsumerSecret,

                this.Token,

                this.TokenSecret,

                method,

                timeStamp,

                nonce,

                out outUrl,

                out querystring);

            HttpWebRequest webRequest = null;

            webRequest = System.Net.WebRequest.Create(url) as HttpWebRequest;

            webRequest.ContentType = "application/x-www-form-urlencoded";   // text/xml

            webRequest.Method = method;

            webRequest.Credentials = CredentialCache.DefaultCredentials;

            webRequest.AllowWriteStreamBuffering = true;

            webRequest.PreAuthenticate = true;

            webRequest.ServicePoint.Expect100Continue = false;

            ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;

            webRequest.Headers.Add("Authorization", "OAuth realm=\"http://api.tumblr.com/\",oauth_consumer_key=\"" + this.ConsumerKey + "\",oauth_token=\"" + this.Token + "\",oauth_signature_method=\"HMAC-SHA1\",oauth_signature=\"" + HttpUtility.UrlEncode(sig) + "\",oauth_timestamp=\"" + timeStamp + "\",oauth_nonce=\"" + nonce + "\",oauth_verifier=\"" + this.Verifier + "\",oauth_version=\"1.0\"");

            

            if (postData != null)

            {

                byte[] fileToSend = Encoding.UTF8.GetBytes(postData);

                webRequest.ContentLength = fileToSend.Length;

                Stream reqStream = webRequest.GetRequestStream();

                reqStream.Write(fileToSend, 0, fileToSend.Length);

                reqStream.Close();

            }

            string returned = WebResponseGet(webRequest);

            

            return returned;

        }

by

Mani

[Marco Tagliaferri]

The code is a bit generic (does not show how you get your signature for example) but from experience I can tell you to check the following things:

 

1) Make sure that you are URL encoding everything that needs to be encoded

 

2) HttpUtility.UrlEncode sometimes produces lower-case characters in the encoded string, this is refused by the server: either make your encode function or make sure you have everything upper case.

 

3) You have to add your request parameters (all the parameters required by the api method you are calling) in the big string that you use to generate the signature (these parameters do NOT have to go in the authorization header)

 

4) Parameter values ALSO have to be URL encoded

 

5) Make sure that the parameters used for generating the signature and the parameters in the authorization header are sorted alphabetically 

 

6) The parameters that have to be passed to the api method (ie: post body, post title) need to be written in the body of the POST request

 

I think there are a few other things, but this is really the major stuff. I am in the process of completing my app, which includes a reusable library for the tumblr v2 api in C# that I wrote from scratch. It is not full production quality code yet, but it has been working pretty well for me so far. If my day job does not kill me in the next few days I hope to be able to share it on codeplex in the near future.