public async Task <IHttpActionResult> GetExternalLogin(string provider, string error = null)
{
if (error != null)
{
return(Redirect(Url.Content("~/") + "#error=" + Uri.EscapeDataString(error)));
}
if (!User.Identity.IsAuthenticated)
{
return(new ChallengeResult(provider, this));
}
ExternalLoginData externalLogin = ExternalLoginData.FromIdentity(User.Identity as ClaimsIdentity);
if (externalLogin == null)
{
return(InternalServerError());
}
if (externalLogin.LoginProvider != provider)
{
Authentication.SignOut(DefaultAuthenticationTypes.ExternalCookie);
return(new ChallengeResult(provider, this));
}
AppUser user = await UserManager.FindAsync(new UserLoginInfo(externalLogin.LoginProvider,
externalLogin.ProviderKey));
bool hasRegistered = user != null;
if (hasRegistered)
{
Authentication.SignOut(DefaultAuthenticationTypes.ExternalCookie);
ClaimsIdentity oAuthIdentity = await user.GenerateUserIdentityAsync(UserManager,
OAuthDefaults.AuthenticationType);
ClaimsIdentity cookieIdentity = await user.GenerateUserIdentityAsync(UserManager,
CookieAuthenticationDefaults.AuthenticationType);
AuthenticationProperties properties = OAuthProvider.CreateProperties(user);
Authentication.SignIn(properties, oAuthIdentity, cookieIdentity);
}
else
{
IEnumerable <Claim> claims = externalLogin.GetClaims();
ClaimsIdentity identity = new ClaimsIdentity(claims, OAuthDefaults.AuthenticationType);
Authentication.SignIn(identity);
}
return(Ok());
}