How do I use OAuth to connect to the Etrade API?

Question

E-Trade released their API recently and provided technical documentation which is somewhat useful but not complete.

Does anyone have a fully working example in C#

Answer 1

I was able to connect using the DevDefined OAuth Library, but i had to make some tweeks to the source to get it to work properly. I forked the repo so you can download the src i used, and build you a .dll.

Repo: GitHub

Example Class:

 public abstract class BaseOAuthRepository
{

    private static string REQUEST_URL = "https://etws.etrade.com/oauth/request_token";
    private static string AUTHORIZE_URL = "https://us.etrade.com/e/t/etws/authorize";
    private static string ACCESS_URL = "https://etws.etrade.com/oauth/access_token";

    private readonly TokenBase _tokenBase;
    private readonly string _consumerSecret;

    protected BaseOAuthRepository(TokenBase tokenBase, 
                                  string consumerSecret)
    {
        _tokenBase = tokenBase;
        _consumerSecret = consumerSecret;
    }

    public TokenBase MyTokenBase
    {
        get { return _tokenBase; }
    }

    public string MyConsumerSecret
    {
        get { return _consumerSecret; }
    }


    public OAuthSession CreateSession()
    {
        var consumerContext = new OAuthConsumerContext
        {
            ConsumerKey = MyTokenBase.ConsumerKey,
            ConsumerSecret = MyConsumerSecret,
            SignatureMethod = SignatureMethod.HmacSha1,
            UseHeaderForOAuthParameters = true,
            CallBack = "oob"
        };

        var session = new OAuthSession(consumerContext, REQUEST_URL, AUTHORIZE_URL, ACCESS_URL);    
        return session;
    }

    public IToken GetAccessToken(OAuthSession session)
    {
        IToken requestToken = session.GetRequestToken();
        string authorizationLink = session.GetUserAuthorizationUrlForToken(MyTokenBase.ConsumerKey, requestToken);
        Process.Start(authorizationLink);
        Console.Write("Please enter pin from browser: ");
        string pin = Console.ReadLine();
        IToken accessToken = session.ExchangeRequestTokenForAccessToken(requestToken, pin.ToUpper());

        return accessToken;
    }

    public string GetResponse(OAuthSession session, string url)
    {
        IToken accessToken = MyTokenBase;

        var response = session.Request(accessToken).Get().ForUrl(url).ToString();
        return response;
    }

    public XDocument GetWebResponseAsXml(HttpWebResponse response)
    {
        XmlReader xmlReader = XmlReader.Create(response.GetResponseStream());
        XDocument xdoc = XDocument.Load(xmlReader);
        xmlReader.Close();
        return xdoc;
    }

    public string GetWebResponseAsString(HttpWebResponse response)
    {
        Encoding enc = System.Text.Encoding.GetEncoding(1252);
        StreamReader loResponseStream = new
        StreamReader(response.GetResponseStream(), enc);
        return loResponseStream.ReadToEnd();
    }
}