Yeah, I had the same problem… Didn’t understand what the heck was going on, since I’m new to OAuth. Keep in mind that you need to pass variables in alphabetical order! And, your signature must have the same variables as the post body (I think ideally the code should be rewritten and done in the opposite order; first create the body and then the signature. Anyway. This messy code works for me:
var oauth_token = "[INSERT THIS]";
var oauth_token_secret = "[INSERT THIS]";
var oauth_consumer_key = "[INSERT THIS]";
var oauth_consumer_secret = "[INSERT THIS]";
var screen_name = "[INSERT THIS]";
// message api details
var resource_url = "https://api.twitter.com/1.1/statuses/user_timeline.json";
// oauth implementation details
var oauth_version = "1.0";
var oauth_signature_method = "HMAC-SHA1";
// unique request details
var oauth_nonce = Convert.ToBase64String(new ASCIIEncoding().GetBytes(DateTime.Now.Ticks.ToString()));
var timeSpan = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
var oauth_timestamp = Convert.ToInt64(timeSpan.TotalSeconds).ToString();
// create oauth signature
var baseFormat = "count=1&exclude_replies=1&include_entities=false&include_rts=false&oauth_consumer_key={0}&oauth_nonce={1}&oauth_signature_method={2}&oauth_timestamp={3}&oauth_token={4}&oauth_version={5}&screen_name={6}&trim_user=1";
var baseString = string.Format(baseFormat,
oauth_consumer_key,
oauth_nonce,
oauth_signature_method,
oauth_timestamp,
oauth_token,
oauth_version,
Uri.EscapeDataString(screen_name)
);
baseString = string.Concat("GET&", Uri.EscapeDataString(resource_url), "&", Uri.EscapeDataString(baseString));
var compositeKey = string.Concat(Uri.EscapeDataString(oauth_consumer_secret), "&", Uri.EscapeDataString(oauth_token_secret));
string oauth_signature;
using (HMACSHA1 hasher = new HMACSHA1(ASCIIEncoding.ASCII.GetBytes(compositeKey))) {
oauth_signature = Convert.ToBase64String(
hasher.ComputeHash(ASCIIEncoding.ASCII.GetBytes(baseString)));
}
// create the request header
var headerFormat = "OAuth oauth_nonce=\"{0}\", oauth_signature_method=\"{1}\", oauth_timestamp=\"{2}\", oauth_consumer_key=\"{3}\", oauth_token=\"{4}\", oauth_signature=\"{5}\", oauth_version=\"{6}\"";
var authHeader = string.Format(headerFormat,
Uri.EscapeDataString(oauth_nonce),
Uri.EscapeDataString(oauth_signature_method),
Uri.EscapeDataString(oauth_timestamp),
Uri.EscapeDataString(oauth_consumer_key),
Uri.EscapeDataString(oauth_token),
Uri.EscapeDataString(oauth_signature),
Uri.EscapeDataString(oauth_version)
);
// make the request
ServicePointManager.Expect100Continue = false;
var postBody = "screen_name=" + Uri.EscapeDataString(screen_name);//
resource_url += "?" + postBody + "&count=1&exclude_replies=1&include_entities=false&include_rts=false&trim_user=1";
Response.Write(resource_url);
//Response.End();
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(resource_url);
request.Headers.Add("Authorization", authHeader);
request.Method = "GET";
request.ContentType = "application/x-www-form-urlencoded";
WebResponse response = request.GetResponse();
string responseData = new StreamReader(response.GetResponseStream()).ReadToEnd();
