Chilkat Online Tools

The C# Source Code for this Page

             
@{

    Layout = "~/_LayoutPage1.cshtml";
}

@functions {

    // Exchange the authorization code for an access token returned in jsonToken.
    private static bool ExchangeCodeForToken(string uri, string body, Chilkat.JsonObject jsonToken)
    {
        var request = (HttpWebRequest)WebRequest.Create(uri);
        request.Method = "POST";
        request.Accept = "application/json";
        request.ContentType = "application/x-www-form-urlencoded";

        request.ContentLength = body.Length;

        using (Stream requestStream = request.GetRequestStream())
        {
            StreamWriter writer = new StreamWriter(requestStream);
            writer.Write(body);
            writer.Close();
        }

        var response = (HttpWebResponse)request.GetResponse();

        using (Stream responseStream = response.GetResponseStream())
        {
            var reader = new StreamReader(responseStream);
            string jsonStr = reader.ReadToEnd();
            reader.Close();
            jsonToken.Load(jsonStr);
        }

        return jsonToken.HasMember("access_token");
    }

}

@{
    string access_token = "";
    string state = "";
    string redirect_uri = "https://tools.chilkat.io/coinbase_oauth2.cshtml";
    string clientId = "a39ec72a986e432eec055815f21ca1190e2971caf913f4b44adcf7ad328b6082";
    string clientSecret = "<secret>CLIENT_SECRET</secret>";
    Chilkat.JsonObject jsonAccessToken = new Chilkat.JsonObject();


    // Check to see if this is our redirect containing the access token.
    if (!string.IsNullOrEmpty(Request.Params["state"]))
    {
        state = Request["state"];

        // Make sure this is the redirect for our session.
        if (!state.Equals(Session["oauth2_state"]))
        {
            access_token = "invalid_state";
        }
        else if (!string.IsNullOrEmpty(Request.Params["code"]))
        {
            string authorizationCode = Request["code"];

            string bodyTemplate = "client_id={0}&client_secret={1}&code={2}&grant_type=authorization_code&redirect_uri={3}&access_type=offline";
            var formUrlEncodedBody = string.Format(bodyTemplate,
                WebUtility.UrlEncode(clientId),
                WebUtility.UrlEncode(clientSecret.Replace("<secret>", "").Replace("</secret>", "")),
                WebUtility.UrlEncode(authorizationCode),
                WebUtility.UrlEncode(redirect_uri));

            if (ExchangeCodeForToken("https://api.coinbase.com/oauth/token", formUrlEncodedBody, jsonAccessToken))
            {
                access_token = jsonAccessToken.StringOf("access_token");
            }
            else
            {
                access_token = "exchange_code_for_token_failed";
            }
        }
    }
}

@{

    Chilkat.HttpRequest req = new Chilkat.HttpRequest();
    req.AddParam("client_id", clientId);
    req.AddParam("redirect_uri", redirect_uri);
    req.AddParam("response_type", "code");
    req.AddParam("scope", "wallet:user:read");
    string stateData = "12345678";  // Replace this with random data..
    req.AddParam("state", stateData);
    Session["oauth2_state"] = stateData;

    string auth_url = "https://www.coinbase.com/oauth/authorize?" + req.GetUrlEncodedParams();

}

<div class="container">
    <h2>Obtain Coinbase OAuth2 Access Token</h2>
    <p>
        This tool demonstrates how to get a Coinbase OAuth2 access token using
        three-legged OAuth2 in an ASP.NET application.  This is also known as the "authorization code grant flow".
        This is when your ASP.NET app acts on the behalf of a third-party user, your app must obtain the user's permission
        before it can make requests that access and update that third-party's confidential resources. A User access token carries
        a third-party's authorization to access specific resources, and this type of token is obtained through the authorization code grant flow.
    </p>
    <div class="panel panel-default">
        <div class="panel-body">
            <a href="@auth_url" class="btn btn-primary" role="button">Begin OAuth2</a>
        </div>
    </div>
    <div class="panel panel-default">
        @{
            if (!string.IsNullOrEmpty(access_token))
            {
                @:<p><b>Coinbase access token:</b> @access_token</p>
            }
            if (!string.IsNullOrEmpty(state))
            {
                @:<p>state: @state</p>
            }
        }
    </div>

    <div class="panel panel-default">
        <h2>The C# Source Code for this Page</h2>
        <pre>
        @{ 
            Chilkat.FileAccess fac = new Chilkat.FileAccess();
            string path = Server.MapPath("~/coinbase_oauth2.cshtml");
            string src = fac.ReadEntireTextFile(path,"utf-8");
            Chilkat.StringBuilder sbTemp = new Chilkat.StringBuilder();
            sbTemp.Append(src);
            sbTemp.ReplaceAllBetween("<secret>", "</secret>", "CLIENT_SECRET", false);
            src = sbTemp.GetAsString();
            @: @src
        }
        </pre>
    </div>
</div>