Authenticate with API using OpenID connect from a Windows Service - windows-services

Question

I've got a cloud migration coming up and we previously did a lot of work transferring data between on-prem databases. The cloud provider is building API's for us to interface with the db once it's in the cloud, so I'm trying to write a Windows Service that will periodically suck some data out of our other on-prem db and post it to the cloud db. I'm having trouble figuring out how to implement OpenID Connect authentication in c# in a windows service. All the examples I've seen are web applications. Has anyone tried this?
If anyone has a better idea than a windows service, I'm open to it.

Answer 1

What you should look for is the client credentials flow (part of OpenID Connect). It is the flow you use when you have no user involved when requesting tokens.
To get a token, you can use the IdentityModel helper library and you can find sample code here:
If you don't want to use a windows service, then the alternative is to create a console application that you schedule to be called using the windows built in task scheduler.
Alternatively, take a look at HangFire.

Answer 2

I've got my service talking with the API. The basic flow is that you request a Bearer token, then pass the token in corresponding requests. Here's an example of the function I'm using to request tokens:
public static async Task<string> RequestTokenAsync()
{
var client = new HttpClient();
string token;
var con = new List<KeyValuePair<string, string>>
{
new KeyValuePair<string, string>("client_id", "XXXXX"),
new KeyValuePair<string, string>("client_secret", "XXXXX"),
new KeyValuePair<string, string>("grant_type", "password"),
new KeyValuePair<string, string>("username", "XXXXX"),
new KeyValuePair<string, string>("password", "XXXXX"),
new KeyValuePair<string, string>("device_id", "XXXXX"),
new KeyValuePair<string, string>("company", "XXXXX")
};
var request = new HttpRequestMessage
{
Method = HttpMethod.Post,
RequestUri = new Uri("https://whatever/connect/token"),
Content = new FormUrlEncodedContent(con)
{
Headers =
{
ContentType = new MediaTypeHeaderValue("application/x-www-form-urlencoded")
}
}
};
try
{
using (var response = await client.SendAsync(request))
{
response.EnsureSuccessStatusCode();
var body = await response.Content.ReadAsStringAsync();
token = body;
}
}
catch (Exception ex)
{
return "ERROR: " + ex.Message;
}
Dictionary<string, object> values =
JsonConvert.DeserializeObject<Dictionary<string, object>>(token);
values.TryGetValue("access_token", out object extractedToken);
return extractedToken.ToString();
}
And here's an example of using the token:
public static async Task<List<Location>> GetLocations()
{
List<Location> result = new List<Location>();
string jsonResponse;
var client = new HttpClient();
string token = await RequestTokenAsync();
var request = new HttpRequestMessage
{
Method = HttpMethod.Get,
RequestUri = new Uri("https://whatever/v1/Locations"),
};
request.Headers.TryAddWithoutValidation("Authorization", "Bearer " + token);
try
{
using (var response = await client.SendAsync(request))
{
response.EnsureSuccessStatusCode();
var body = await response.Content.ReadAsStringAsync();
jsonResponse = body.ToString();
try
{
result = JsonConvert.DeserializeObject<List<Location>>(jsonResponse);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message + ex.StackTrace);
}
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message + ex.StackTrace);
}
return result;
}