IDX12709: CanReadToken() returned false. JWT is not well formed - Open ID Connect Authentication - asp.net-mvc-5

Question

We are implementing authentication in asp.net mvc application using open id connect.
app.UseKentorOwinCookieSaver();
app.UseCookieAuthentication(new CookieAuthenticationOptions
{
AuthenticationType = "Cookies",
CookieManager = new Microsoft.Owin.Host.SystemWeb.SystemWebChunkingCookieManager()
});
app.UseOpenIdConnectAuthentication(
new OpenIdConnectAuthenticationOptions
{
ClientId = clientId,
Authority = authority,
PostLogoutRedirectUri = postLogoutRedirectUri,
RedirectUri = RedirectUri,
ResponseType = OpenIdConnectResponseType.Code,
TokenValidationParameters = new TokenValidationParameters
{
ValidateIssuerSigningKey = true,
IssuerSigningKey = new SymmetricSecurityKey(Encoding.ASCII.GetBytes(secretkey)),
ValidateIssuer = true,
ValidIssuer = authority,
ValidateAudience = true
// ValidAudience = strAudience
},
Notifications = new OpenIdConnectAuthenticationNotifications()
{
// when an auth code is received...
AuthorizationCodeReceived = (context) => {
// get the OpenID Connect code passed from Azure AD on successful auth
string code = context.Code;
var handler = new JwtSecurityTokenHandler();
var token = handler.ReadJwtToken(code);
//// successful auth
return Task.FromResult(0);
},
SecurityTokenValidated = (ctx) =>
{
// We can remove claims that are not necessary in this context, mitigating the cookie size.
var identity = ctx.AuthenticationTicket.Identity;
return Task.FromResult(0);
},
AuthenticationFailed = (context) => {
context.HandleResponse();
return Task.FromResult(0);
}
}
});
Authentication is successful, and I am able to get the code.
I am using Authorize attribute in my controller.
Using msal, we received auth token and id_token. I am getting the proper tokens, still after getting tokens, I am getting Infinite loop. I am used UseKentorOwinCookieSaver also. But nothing is working.

Answer 1

The authorization code is not a JWT.
You use it to get JWTs from Azure AD's token endpoint.
You can use MSAL (Microsoft Authentication Library) for this, or make the call yourself.
https://learn.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-auth-code-flow