(C++) Twitter OAuth1 Authorization (3-legged)

Demonstrates 3-legged OAuth1 authorization for Twitter.

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#include <CkHttp.h>
#include <CkHttpRequest.h>
#include <CkHttpResponse.h>
#include <CkHashtable.h>
#include <CkStringBuilder.h>
#include <CkSocket.h>
#include <CkTask.h>
#include <CkJsonObject.h>
#include <CkFileAccess.h>

void ChilkatSample(void)
    {
    const char *consumerKey = "TWITTER_CONSUMER_KEY";
    const char *consumerSecret = "TWITTER_CONSUMER_SECRET";

    const char *requestTokenUrl = "https://api.twitter.com/oauth/request_token";
    const char *authorizeUrl = "https://api.twitter.com/oauth/authorize";
    const char *accessTokenUrl = "https://api.twitter.com/oauth/access_token";

    // The port number is picked at random. It's some unused port that won't likely conflict with anything else..
    const char *callbackUrl = "http://localhost:3017/";
    int callbackLocalPort = 3017;

    // The 1st step in 3-legged OAuth1.0a is to send a POST to the request token URL to obtain an OAuth Request Token
    CkHttp http;
    bool success;

    http.put_OAuth1(true);
    http.put_OAuthConsumerKey(consumerKey);
    http.put_OAuthConsumerSecret(consumerSecret);

    CkHttpRequest req;
    req.AddParam("oauth_callback",callbackUrl);

    CkHttpResponse *resp = http.PostUrlEncoded(requestTokenUrl,req);
    if (http.get_LastMethodSuccess() != true) {
        std::cout << http.lastErrorText() << "\r\n";
        return;
    }

    // If successful, the resp.BodyStr contains something like this:  
    // oauth_token=-Wa_KwAAAAAAxfEPAAABV8Qar4Q&oauth_token_secret=OfHY4tZBX2HK4f7yIw76WYdvnl99MVGB&oauth_callback_confirmed=true
    std::cout << resp->bodyStr() << "\r\n";

    if (resp->get_StatusCode() != 200) {
        std::cout << "Failed response status code: " << resp->get_StatusCode() << "\r\n";
        delete resp;
        return;
    }

    CkHashtable hashTab;
    hashTab.AddQueryParams(resp->bodyStr());

    const char *requestToken = hashTab.lookupStr("oauth_token");
    const char *requestTokenSecret = hashTab.lookupStr("oauth_token_secret");
    http.put_OAuthTokenSecret(requestTokenSecret);

    delete resp;

    std::cout << "oauth_token = " << requestToken << "\r\n";
    std::cout << "oauth_token_secret = " << requestTokenSecret << "\r\n";

    // ---------------------------------------------------------------------------
    // The next step is to form a URL to send to the authorizeUrl
    // This is an HTTP GET that we load into a popup browser.
    CkStringBuilder sbUrlForBrowser;
    sbUrlForBrowser.Append(authorizeUrl);
    sbUrlForBrowser.Append("?oauth_token=");
    sbUrlForBrowser.Append(requestToken);
    const char *url = sbUrlForBrowser.getAsString();

    // At this point, your application should load the URL in a browser.
    // For example, 
    // in C#: System.Diagnostics.Process.Start(url);
    // in Java: Desktop.getDesktop().browse(new URI(url));
    // in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
    //              wsh.Run url
    // in Xojo: ShowURL(url)  (see http://docs.xojo.com/index.php/ShowURL)
    // in Dataflex: Runprogram Background "c:\Program Files\Internet Explorer\iexplore.exe" sUrl        
    // The Microsoft account owner would interactively accept or deny the authorization request.

    // Add the code to load the url in a web browser here...
    // Add the code to load the url in a web browser here...
    // Add the code to load the url in a web browser here...

    // When the url is loaded into a browser, the response from Twitter will redirect back to localhost:3017
    // We'll need to start a socket that is listening on port 3017 for the callback from the browser.
    CkSocket listenSock;

    int backLog = 5;
    success = listenSock.BindAndListen(callbackLocalPort,backLog);
    if (success != true) {
        std::cout << listenSock.lastErrorText() << "\r\n";
        return;
    }

    // Wait for the browser's connection in a background thread.
    // (We'll send load the URL into the browser following this..)
    // Wait a max of 60 seconds before giving up.
    int maxWaitMs = 60000;
    CkTask *task = listenSock.AcceptNextConnectionAsync(maxWaitMs);
    task->Run();

    // At this point, your application should load the URL in a browser.
    // For example, 
    // in C#: System.Diagnostics.Process.Start(url);
    // in Java: Desktop.getDesktop().browse(new URI(url));
    // in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
    //              wsh.Run url
    // in Xojo: ShowURL(url)  (see http://docs.xojo.com/index.php/ShowURL)
    // in Dataflex: Runprogram Background "c:\Program Files\Internet Explorer\iexplore.exe" sUrl        
    // The Twitter account owner would interactively accept or deny the authorization request.

    // Add the code to load the url in a web browser here...
    // Add the code to load the url in a web browser here...
    // Add the code to load the url in a web browser here...
    // System.Diagnostics.Process.Start(url);

    // Wait for the listenSock's task to complete.
    success = task->Wait(maxWaitMs);
    if (!success || (task->get_StatusInt() != 7) || (task->get_TaskSuccess() != true)) {
        if (!success) {
            // The task.LastErrorText applies to the Wait method call.
            std::cout << task->lastErrorText() << "\r\n";
        }
        else {
            // The ResultErrorText applies to the underlying task method call (i.e. the AcceptNextConnection)
            std::cout << task->status() << "\r\n";
            std::cout << task->resultErrorText() << "\r\n";
        }

        delete task;
        return;
    }

    // If we get to this point, the connection from the browser arrived and was accepted.

    // We no longer need the listen socket...
    // Stop listening on port 3017.
    listenSock.Close(10);

    // First get the connected socket.
    CkSocket sock;
    sock.LoadTaskResult(*task);
    delete task;

    // Read the start line of the request..
    const char *startLine = sock.receiveUntilMatch("\r\n");
    if (sock.get_LastMethodSuccess() != true) {
        std::cout << sock.lastErrorText() << "\r\n";
        return;
    }

    // Read the request header.
    const char *requestHeader = sock.receiveUntilMatch("\r\n\r\n");
    if (sock.get_LastMethodSuccess() != true) {
        std::cout << sock.lastErrorText() << "\r\n";
        return;
    }

    // The browser SHOULD be sending us a GET request, and therefore there is no body to the request.
    // Once the request header is received, we have all of it.
    // We can now send our HTTP response.
    CkStringBuilder sbResponseHtml;
    sbResponseHtml.Append("<html><body><p>Chilkat thanks you!</b></body</html>");

    CkStringBuilder sbResponse;
    sbResponse.Append("HTTP/1.1 200 OK\r\n");
    sbResponse.Append("Content-Length: ");
    sbResponse.AppendInt(sbResponseHtml.get_Length());
    sbResponse.Append("\r\n");
    sbResponse.Append("Content-Type: text/html\r\n");
    sbResponse.Append("\r\n");
    sbResponse.AppendSb(sbResponseHtml);

    sock.SendString(sbResponse.getAsString());
    sock.Close(50);

    // The information we need is in the startLine.
    // For example, the startLine will look like this:
    //  GET /?oauth_token=abcdRQAAZZAAxfBBAAABVabcd_k&oauth_verifier=9rdOq5abcdCe6cn8M3jabcdj3Eabcd HTTP/1.1
    CkStringBuilder sbStartLine;
    sbStartLine.Append(startLine);
    int numReplacements = sbStartLine.Replace("GET /?","");
    numReplacements = sbStartLine.Replace(" HTTP/1.1","");
    sbStartLine.Trim();

    // oauth_token=abcdRQAAZZAAxfBBAAABVabcd_k&oauth_verifier=9rdOq5abcdCe6cn8M3jabcdj3Eabcd
    std::cout << "startline: " << sbStartLine.getAsString() << "\r\n";

    hashTab.Clear();
    hashTab.AddQueryParams(sbStartLine.getAsString());

    requestToken = hashTab.lookupStr("oauth_token");
    const char *authVerifier = hashTab.lookupStr("oauth_verifier");

    // ------------------------------------------------------------------------------
    // Finally , we must exchange the OAuth Request Token for an OAuth Access Token.

    http.put_OAuthToken(requestToken);
    http.put_OAuthVerifier(authVerifier);

    // We don't need the "Authorization: OAuth ..." header for this POST.
    http.put_OAuth1(false);
    req.RemoveParam("oauth_callback");
    req.AddParam("oauth_verifier",authVerifier);
    req.AddParam("oauth_token",requestToken);

    resp = http.PostUrlEncoded(accessTokenUrl,req);
    if (http.get_LastMethodSuccess() != true) {
        std::cout << http.lastErrorText() << "\r\n";
        return;
    }

    // Make sure a successful response was received.
    if (resp->get_StatusCode() != 200) {
        std::cout << resp->statusLine() << "\r\n";
        std::cout << resp->header() << "\r\n";
        std::cout << resp->bodyStr() << "\r\n";
        return;
    }

    // If successful, the resp.BodyStr contains something like this:
    // oauth_token=85123455-fF41296Bi3daM8eCo9Y5vZabcdxXpRv864plYPOjr&oauth_token_secret=afiYJOgabcdSfGae7BDvJVVTwys8fUGpra5guZxbmFBZo&user_id=85612355&screen_name=chilkatsoft&x_auth_expires=0
    std::cout << resp->bodyStr() << "\r\n";

    hashTab.Clear();
    hashTab.AddQueryParams(resp->bodyStr());

    const char *accessToken = hashTab.lookupStr("oauth_token");
    const char *accessTokenSecret = hashTab.lookupStr("oauth_token_secret");
    const char *userId = hashTab.lookupStr("user_id");
    const char *screenName = hashTab.lookupStr("screen_name");

    delete resp;

    // The access token + secret is what should be saved and used for
    // subsequent REST API calls.
    std::cout << "Access Token = " << accessToken << "\r\n";
    std::cout << "Access Token Secret = " << accessTokenSecret << "\r\n";
    std::cout << "user_id = " << userId << "\r\n";
    std::cout << "screen_name  = " << screenName << "\r\n";

    // Save this access token for future calls.
    // Just in case we need user_id and screen_name, save those also..
    CkJsonObject json;
    json.AppendString("oauth_token",accessToken);
    json.AppendString("oauth_token_secret",accessTokenSecret);
    json.AppendString("user_id",userId);
    json.AppendString("screen_name",screenName);

    CkFileAccess fac;
    fac.WriteEntireTextFile("qa_data/tokens/twitter.json",json.emit(),"utf-8",false);

    std::cout << "Success." << "\r\n";
    }