Sign in with Linkedin

Question

How do I implement the login method for Linkedin so that people can simply click a button and use their Linkedin account to login, like on Facebook or Twitter? Both use OAuth, but I found specific libraries for them that are easy to use. For Linkedin, I found only some sample code in DotNetOpenAuth, but I can't make any sense out of it.

Are there libraries that I can use to facilitate LinkedIn login? Or any tutorials on how to do this in ASP.NET MVC with DotNetOpenAuth 4?

Answer 1

Here's what a pretty solid example looks like.

http://mrsarker.wordpress.com/2011/08/20/linkedin-rest-api-in-asp-net-mvc/

[HandleError] public class LinkedInController : Controller { public ActionResult index() { return AuthenticateToLinkedIn(); } static string token_secret = ""; public ActionResult AuthenticateToLinkedIn() { var credentials = new OAuthCredentials { CallbackUrl = "http://localhost/home/callback", ConsumerKey = ConfigurationManager.AppSettings["ConsumerKey"], ConsumerSecret = ConfigurationManager.AppSettings["ConsumerSecret"], Verifier = "123456", Type = OAuthType.RequestToken }; var client = new RestClient { Authority = "https://api.linkedin.com/uas/oauth", Credentials = credentials }; var request = new RestRequest { Path = "requestToken" }; RestResponse response = client.Request(request); token = response.Content.Split('&').Where(s => s.StartsWith("oauth_token=")).Single().Split('=')[1]; token_secret = response.Content.Split('&').Where(s => s.StartsWith("oauth_token_secret=")).Single().Split('=')[1]; Response.Redirect("https://api.linkedin.com/uas/oauth/authorize?oauth_token=" + token); return null; } string token = ""; string verifier = ""; public ActionResult Callback() { token = Request["oauth_token"]; verifier = Request["oauth_verifier"]; var credentials = new OAuthCredentials { ConsumerKey = ConfigurationManager.AppSettings["ConsumerKey"], ConsumerSecret = ConfigurationManager.AppSettings["ConsumerSecret"], Token = token, TokenSecret = token_secret, Verifier = verifier, Type = OAuthType.AccessToken, ParameterHandling = OAuthParameterHandling.HttpAuthorizationHeader, SignatureMethod = OAuthSignatureMethod.HmacSha1, Version = "1.0" }; var client = new RestClient { Authority = "https://api.linkedin.com/uas/oauth", Credentials = credentials, Method = WebMethod.Post }; var request = new RestRequest { Path = "accessToken" }; RestResponse response = client.Request(request); string content = response.Content; string accessToken = response.Content.Split('&').Where(s => s.StartsWith("oauth_token=")).Single().Split('=')[1]; string accessTokenSecret = response.Content.Split('&').Where(s => s.StartsWith("oauth_token_secret=")).Single().Split('=')[1]; var company = new LinkedInService(accessToken, accessTokenSecret).GetCompany(162479); // Some commented call to API //company = new LinkedInService(accessToken, accessTokenSecret).GetCompanyByUniversalName("linkedin"); // var companies = new LinkedInService(accessToken, accessTokenSecret).GetCompaniesByEmailDomain("apple.com"); // var companies1 = new LinkedInService(accessToken, accessTokenSecret).GetCompaniesByEmailDomain("linkedin.com"); // var companies2= new LinkedInService(accessToken, accessTokenSecret).GetCompaniesByIdAnduniversalName("162479", "linkedin"); //var people = new LinkedInService(accessToken, accessTokenSecret).GetPersonById("f7cp5sKscd"); //var people = new LinkedInService(accessToken, accessTokenSecret).GetCurrentUser(); //string url = Url.Encode("http://bd.linkedin.com/pub/rakibul-islam/37/522/653"); //var people = new LinkedInService(accessToken, accessTokenSecret).GetPeoPleByPublicProfileUrl(url); //var peopleSearchresult = new LinkedInService(accessToken, accessTokenSecret).SearchPeopleByKeyWord("Princes"); var peopleSearchresult = new LinkedInService(accessToken, accessTokenSecret).GetPeopleByFirstName("Mizan"); String companyName = company.Name; return Content(companyName); } } public class LinkedInService { private const string URL_BASE = "http://api.linkedin.com/v1"; public static string ConsumerKey { get { return ConfigurationManager.AppSettings["ConsumerKey"]; } } public static string ConsumerKeySecret { get { return ConfigurationManager.AppSettings["ConsumerSecret"]; } } public string AccessToken { get; set; } public string AccessTokenSecret { get; set; } public LinkedInService(string accessToken, string accessTokenSecret) { this.AccessToken = accessToken; this.AccessTokenSecret = accessTokenSecret; } private OAuthCredentials AccessCredentials { get { return new OAuthCredentials { Type = OAuthType.AccessToken, SignatureMethod = OAuthSignatureMethod.HmacSha1, ParameterHandling = OAuthParameterHandling.HttpAuthorizationHeader, ConsumerKey = ConsumerKey, ConsumerSecret = ConsumerKeySecret, Token = AccessToken, TokenSecret = AccessTokenSecret }; } } #region Helper private RestResponse GetResponse(string path) { var client = new RestClient() { Authority = URL_BASE, Credentials = AccessCredentials, Method = WebMethod.Get }; var request = new RestRequest { Path = path }; return client.Request(request); } private T Deserialize(string xmlContent) { MemoryStream memoryStream = new MemoryStream(Encoding.ASCII.GetBytes(xmlContent)); XmlSerializer deserializer = new XmlSerializer(typeof(T)); return (T)deserializer.Deserialize(new StringReader(xmlContent)); } #endregion // methods removed for brevity. check the original link for full source } 

Answer 2

If you do not want to code it yourself, you can always look at a third-party solution, for example, the Janrain RPX solution: http://developers.janrain.com/ . This will give you a LinkedIn link plus many more.