OAUTH is an authentication system used by companies such as Google, Twitter, Vimeo, Linked in etc, and it is much more complex than basic authentication, but it. Web Spider. You may need to know the status and update a ProgressBar during the file download or use credentials before making the request. Here it is, an example that covers. Some of the companies Ive worked for have had reporting contracts with smaller 3rd party providers. Campaign or website analysis provided by them would have to be. Hello World, OAUTH Network Programming in. NETOAUTH is an authentication system used by companies such as Google, Twitter, Vimeo, Linked in etc, and it is much more complex than basic authentication, but it really is just about exchanging data between your server and the authentication provider. This is meant to be a Hello World example, showing an easy way to implement OAuth 2, without using any third party frameworks. The example uses C ASPX, and Google API. I will be demonstrating a call to Google Analytics API, but any Google API works similarly. I cant say the same for Twitter Vimeo Linked. In, but the flow of data should be the same. Prerequisites Some windows hosting to host the callback page. Sign up through the Google API Console to the Google Analytics API, and set up a client ID for Web Applications. Flow of actions overview The reason why OAuth is popular, is because it means that API consumers i. Google credentials. You never ask the user for their username and password, you send them to Google and Google enter their username and password on Googles page. Google will then send you back proof that the username and password were correct, but will never tell you what the username and password was. The first step, therefore is to send a user to google using a special link. A simple link like this does lt a hrefhttps accounts. Fprofile redirecturihttp3. A2. F2. Fdananos. Systems Of Linear Inequalities Word Problems Pdf. Foauth2. Fcallback. A2. F2. Fwww. googleapis. Fauth2. Fanalytics gt Loginlt a Lets break down that link https accounts. Fprofile redirecturihttp3. A2. F2. Fdananos. Foauth2. Fcallback. A2. F2. Fwww. googleapis. Fauth2. Fanalytics. The important bits are clientid You get this from your Google API Consoleredirecturi You set this in your Google API, and it tells Google where to send the user after they have logged in. This sets which APIs you would like to use, In my case, Google Analytics. Once the user signs into Google, then its up to some server side code to interpret the response from Google, and use it to access Googles APIs using the users credentials. This is where the callback script comes in, which is simply an ASPX page that is hosted on your server. The steps that this script must do is 1. Exchange the authorisation code provided by Google into a access token. Use the access token when calling Googles API methods. Lets deal with the first step, the exchange of the authorisation code. Google will redirect back to your URL with extra parameters, like this callback. QKG8zbh. Ri hi. RXEyo. Uq. Hc. 8. IQf. Ol. ZT3b. DNXFg. QIThe code value needs to be sent to https accounts. POST data code taken from the querystring sent back from googleredirecturi from your Google API consoleclientid from  your Google API consolescope   emptyclientsecret from your Google API consolegranttype set to authorizationcode. This is the C code I used to make this request  My Access credentials removedstring str. C# Webclient File Credentials' title='C# Webclient File Credentials' />Token Request. Query. Stringcode System. Net. Web. Client wc new System. Net. Web. Client string str. Exchange code0 str. Exchange redirecturi str. Exchange clientid. Exchange scope str. Exchange clientsecret. Exchange string. Formatstr. Exchange,str. Token string str. The. NET API Reference documentation has a new home. Visit the. NET API Browser on docs. Gets or sets a collection of query. This is a post detailing how you perform active authentication to SharePoint Online in Office 365. Active authentication is required when you need to authenticate in. Net tips. ftp2. 0cvb. Url https accounts. HeadersSystem. Net. Http. Request. Header. Content. Type applicationx www form urlencoded string str. Html wc. Upload. Stringstr. Url, str. Exchange Returned, is a small piece of JSON in this format accesstoken ya. AHES6. ZTBNv. 8w. BJFPnn. 7r. MPvr. HZse. G6. EUUvf. Yui. PFTx. 3TUTzp. YVEIQ, tokentype Bearer, expiresin 3. One of the best ways to parse this JSON is to use the Java. Script. Serializer object built into. NET, this requires you to define a class that matches the JSON schema, like this public class Root. Objectpublic string accesstoken get set public string tokentype get set public int expiresin get set public string idtoken get set Then using the following code to convert the JSON into a Root. Object object System. Web. Script. Serialization. Java. Script. Serializer js new System. Web. Script. Serialization. Java. Script. Serializer Root. Object ro js. Deserializelt Root. Object str. Html Once we have our Root. Object, we can use the accesstoken to call Google APIs like so System. Net. Web. Client wc. System. Net. Web. Client str. Url https www. Headers. AddAuthorization,Bearer ro. Html wc. 2. Download. Stringstr. Url This then returns the Google Analytics accounts associated with the authenticated Google user, in my case it is. Results 1. start. Index 1. items. Per. Page 1. 00. Link https www. T1. 3 5. 8 0. 9. Z. T2. 2 3. 4 5. 5. Z. Link. And there you have it, weve successfully used OAuth to authenticate a user against a Google API.