实现Evernote的OAuth授权

 

原理图

第三方OAuth库

由于当中有一个签名的字段，需要实现一些比较复杂的操作。所以使用了danielcrenna的OAuth的库。下载地址https://github.com/danielcrenna/oauth

他里面的实例好像有点问题，好在库本身是可以使用的。而且非常方便。

代码

因为我是本地的程序所以我需要使用一个WebBrowser控件来完成认证授权的过程，另外也是因为是本地程序的原因我的回调地址就设置了一个localHost,这个回调地址必须有，不然会出现401错误，而且之后需要通过这个回调地址获取Verifier.这个回调地址，不一定是要可以访问的。

private String ConsumerKey = "xxxxxx";
private String ConsumerSecret = "xxxxxxyyyyyyy";
private String RequestURI = "https://sandbox.evernote.com/oauth";
private String AuthorizationURI = "https://sandbox.evernote.com/OAuth.action";
private String CallbackURI = "http://localhost/EvernoteAdage";
private String RequestToken;
private String RequestTokenSecret;
private String Verifier;

private string Token;
private long Expires;

private void button2_Click(object sender, RoutedEventArgs e)
{
    RequesCredentials();
    //使用webBrowser，导航到授权的网站
    this.webBrowser1.Navigate(AuthorizationURI + "?oauth_token=" +
                                                        RequestToken);
}

//获取RequestToken和RequestTokenSecret
private void RequesCredentials()
{
    //CallbackUrl是一定要设置的
    OAuthRequest client = OAuthRequest.ForRequestToken(ConsumerKey,
                                        ConsumerSecret);
    client.RequestUrl = RequestURI;
    client.CallbackUrl = CallbackURI;

    String auth = client.GetAuthorizationQuery();
    String url = client.RequestUrl + "?" + auth;
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);

    //获取请求结果
    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
    StreamReader reader = new StreamReader(response.GetResponseStream());
    String result = reader.ReadToEnd();
    reader.Close();
    response.Close();

    //从结果中提取出RequestToken和RequestTokenSecret
    RequestToken = result.Split('&')[0].Split('=')[1];
    RequestTokenSecret = result.Split('&')[1].Split('=')[1];
}

//针对授权的结果的Verifier
private void webBrowser1_Navigating(object sender, NavigatingCancelEventArgs e)
{
    if(e.Uri.ToString().StartsWith("http://localhost/EvernoteAdage"))
    {
        var splitted = e.Uri.ToString().Split('&').Select(s => s.Split('=')).ToDictionary(s => s.First(), s => s.Last());
        if(!splitted.ContainsKey("oauth_verifier"))
        {
            return;
        }
        Verifier = splitted["oauth_verifier"];
        //获取最终的Token
        AccessCredentials();

        //显示结果
        this.textBlock.Text =
            String.Format("Token = {0}\nExpires = {1}",
                           Token, Expires);
        //进行退出处理
        this.webBrowser1.Visibility = Visibility.Hidden;
    }
}

//获取访问所需的Token Expires
private void AccessCredentials()
{
    OAuthRequest Client = OAuthRequest.ForAccessToken(ConsumerKey,
                                                      ConsumerSecret,
                                                      RequestToken,
                                                      RequestTokenSecret,
                                                      Verifier);
    Client.RequestUrl = RequestURI;

    String auth = Client.GetAuthorizationQuery();
    String url = Client.RequestUrl + "?" + auth;
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);

    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
    StreamReader reader = new StreamReader(response.GetResponseStream());
    String result = reader.ReadToEnd();
    reader.Close();
    response.Close();

    var splitted = result.Split('&').Select(s => s.Split('=')).ToDictionary(s => s.First(), s => s.Last());
    String deToken = splitted["oauth_token"];
    String expiresStr = splitted["edam_expires"];

    Token = HttpUtility.UrlDecode(deToken);
    Expires = Convert.ToInt64(expiresStr);
}