function

var deferred = $q.defer();
$http.post([serviceBase, "token"].join(''), data, { headers: { "Content-Type": "application/x-www-form-urlencoded" } }).success(function (response) {
    console.log("login response", response);
    localStorageService.set(_keyAuthorizationData, { token: response.access_token, userName: loginData.userName });
    _authentication.isAuth = true;
    _authentication.userName = loginData.userName;
    deferred.resolve(response);
}).error(function (err, status) {
    _logOut();
    deferred.reject(err);
});
return deferred.promise;
};
   
var _transferPersoon = function (portal, data) {
    var externalAPI = "";
    if (portal == "portal1") {
        externalAPI = "https://urltoportal/webapi/";
    } else if (portal == "portal2") {
        externalAPI = "https://urltoportal/webapi/";
    } else if (portal == "portal3") {
        externalAPI = "https://urltoportal/webapi/";
    } else if (portal == "portal4") {
        externalAPI = "https://urltoportal/webapi/";
    } else {
        externalAPI = serviceBase;
    }

    var tokenData = {
        username: "cactustransfer",
        password: "bbbbbb",
        grant_type: "password"
    };
    var data = ["grant_type=password&username=", "transferaccount", "&password=", "password"].join('');

    $http.post([externalAPI, "token"].join(''), data, { headers: { "Content-Type": "application/x-www-form-urlencoded" } }).success(function (response) {
        return response.access_token;
    })
}
   
{error: "unsupported_grant_type"}
   
public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
    {
        Cactus.Business.DataModel.GEBRUIKER gebruiker = null;
        context.OwinContext.Response.Headers.Add("Access-Control-Allow-Origin", new[] {"*"});

        var identity = new ClaimsIdentity(context.Options.AuthenticationType);

        /*
         * Authenticatie methode voor het verplaatsen van personeel
         * Deze kan niet uitgevoerd worden als het request IP niet in het lijstje van hosts staat.
         * Dit is een extra beveiliging.
         */
        if (context.UserName == "cactustransfer")
        {
            if (!hostVerify.IsValidHost(context.Request.RemoteIpAddress))
            {
                using (UnitOfWork work = new UnitOfWork())
                {
                    gebruiker = work.GebruikerRepository.ValidateUser("transferaccount", "password");
                }
            }
        }

        if (gebruiker == null)
        {
            using (UnitOfWork work = new UnitOfWork())
            {
                gebruiker = work.GebruikerRepository.ValidateUser(context.UserName, context.Password);
                if (gebruiker == null)
                {
                    context.SetError("invalid_grant",
                        "The username or password is incorrect, or you have insufficient rights", context.Request.RemoteIpAddress);
                    return;
                }
            }
        }

        identity.AddClaim(new Claim("sub", context.UserName));
        identity.AddClaim(new Claim("role", "user"));
        identity.AddClaim(new Claim("providerID", gebruiker.gebruikerId.ToString()));
        //identity.AddClaim(new Claim("providerID", gebruiker.persoon.ToString()));

        context.Validated(identity);
    }