'ASP.NET Web API and OpenID Connect: how to get Access Token from Authorization Code
I try to get OpenID Connect running... A user of my Web API managed to get an Authorization Code of a OpenID Connect Provider. How am I supposed to pass this code to my ASP.NET Web API? How do I have to configure OWIN Middleware such that I can get an Access Token using the Authorization Code?
UPDATE: A SPA uses AJAX for communicating with my web service (ASP.NET Web API). In my web service a use OWIN Middleware. I set OpenIDConnect as the authentication mechanism. When the web service is called for the first time it successfully redirected the user to the login page of the OpenID Connect Provider. The user could login and got an Authorization Code as a result. AFAIK this code could now be used (by my web service) to the an Access Token. However, I don't know how to get this code back to my web service (is this done using a header?) and then what to configure to get the Access Token. I guess I could call the token endpoint manually but I would like to take advantage of the OWIN component instead.
Solution 1:[1]
Looks like the recommended approach is to use the AuthorizationCodeReceived
event to exchange the Auth code for an Access Token. Vittorio has a blog entry that outlines the overall flow.
Here's an example from this sample app on GitHub of the Startup.Auth.cs
code to set this up:
app.UseOpenIdConnectAuthentication(
new OpenIdConnectAuthenticationOptions
{
ClientId = clientId,
Authority = Authority,
Notifications = new OpenIdConnectAuthenticationNotifications()
{
AuthorizationCodeReceived = (context) =>
{
var code = context.Code;
ClientCredential credential = new ClientCredential(clientId, appKey);
string tenantID = context.AuthenticationTicket.Identity.FindFirst("http://schemas.microsoft.com/identity/claims/tenantid").Value;
string signedInUserID = context.AuthenticationTicket.Identity.FindFirst(ClaimTypes.NameIdentifier).Value;
AuthenticationContext authContext = new AuthenticationContext(string.Format("https://login.windows.net/{0}", tenantID), new EFADALTokenCache(signedInUserID));
AuthenticationResult result = authContext.AcquireTokenByAuthorizationCode(
code, new Uri(HttpContext.Current.Request.Url.GetLeftPart(UriPartial.Path)), credential, graphResourceID);
return Task.FromResult(0);
},
...
}
Note: The AuthorizationCodeReceived
event is invoked only once when authorization really takes place. If the auth code is already generated and stored, this event is not invoked. You have to logout or clear cookies to force this event to take place.
Solution 2:[2]
BenV already answered the question, but there's more to consider.
class partial Startup
{
public void ConfigureAuth(IAppBuilder app)
{
// ...
app.UseOpenIdConnectAuthentication(new OpenIdConnectAuthenticationOptions
{
ClientId = clientId,
Authority = authority,
Notifications = new OpenIdConnectAuthenticationNotifications() {
AuthorizationCodeReceived = (context) => {
string authorizationCode = context.Code;
// (tricky) the authorizationCode is available here to use, but...
return Task.FromResult(0);
}
}
}
}
}
Two problems:
- First of all,
authorizationCode
will get expired quickly. There's no sense in storing it. - The second problem is that
AuthorizationCodeReceived
event will not get fired for any of the page reloads as long as authorizationCode is not expired and stored inside the session.
What you need to do is to call AcquireTokenByAuthorizationCodeAsync
which will cache it and handle properly inside TokenCache.DefaultShare
:
AuthorizationCodeReceived = (context) => {
string authorizationCode = context.Code;
AuthenticationResult tokenResult = await context.AcquireTokenByAuthorizationCodeAsync(authorizationCode, new Uri(redirectUri), credential);
return Task.FromResult(0);
}
Now, before every call to the resource, invoke AcquireTokenSilentAsync
to get the accessToken (it will use TokenCache or silently use refreshToken ). If token is expired, it will raise AdalSilentTokenAcquisitionException
exception (invoke access code renew procedure).
// currentUser for ClaimsPrincipal.Current.FindFirst("http://schemas.microsoft.com/identity/claims/objectidentifier")
AuthenticationResult authResult = await context.AcquireTokenSilentAsync(resourceUri, credential, currentUser);
Calling AcquireTokenSilentAsync
is very fast if token is cached.
Solution 3:[3]
You need to bypass the default owin validation to do custom Authorization:
new OpenIdConnectAuthenticationOptions
{
...,
TokenValidationParameters = new System.IdentityModel.Tokens.TokenValidationParameters
{
ValidateIssuer = false
},
Solution 4:[4]
This is now built into Microsoft.Owin 4.1.0 or later. You can use SaveTokens
to make the id_token available and then RedeemCode
to get an access token and make that available
app.UseOpenIdConnectAuthentication(
new OpenIdConnectAuthenticationOptions
{
ClientId = clientId,
Authority = authority,
PostLogoutRedirectUri = postLogoutRedirectUri,
ClientSecret = "redacted",
RedirectUri = postLogoutRedirectUri,
//This allows multitenant
//https://github.com/Azure-Samples/guidance-identity-management-for-multitenant-apps/blob/master/docs/03-authentication.md
TokenValidationParameters = new TokenValidationParameters
{
ValidateIssuer = false
},
Notifications = new OpenIdConnectAuthenticationNotifications()
{
AuthenticationFailed = (context) =>
{
return Task.FromResult(0);
}
},
SaveTokens = true,
// Required for the authorization code flow to exchange for tokens automatically
// using this means you will need to provide RedirectUri and ClientSecret
RedeemCode = true
}
);
You can then access the tokens through the HttpContext object
var result = Request.GetOwinContext().Authentication.AuthenticateAsync("Cookies").GetAwaiter().GetResult();
string idToken = result.Properties.Dictionary["id_token"];
string accessToken = result.Properties.Dictionary["access_token"];
Sources: How to get access token from httpcontext using owin and Mvc 5
Solution 5:[5]
TokenValidationParameters = new TokenValidationParameters { NameClaimType = "name", RoleClaimType = ClaimTypes.Role },
This line of code solved my issue. We need to validate the issuer to be false.
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
Solution | Source |
---|---|
Solution 1 | |
Solution 2 | |
Solution 3 | James |
Solution 4 | ToDevAndBeyond |
Solution 5 | 4b0 |