[Bug] "The issuer '(null)' is invalid" error when I request my API with bearer token

Which Version of MSAL are you using ? msal.net 1.9.0

Platform asp.net core 5.0

What authentication flow has the issue?

• Desktop / Mobile
  • Interactive
  • Integrated Windows Auth
  • Username Password
  • Device code flow (browserless)
• Web App
  • Authorization code
  • OBO
• Daemon App
  • Service to Service calls

Other? - please describe;

Is this a new or existing app? This is a new app or experiment

Repro

I have added following lines of code.

// startup.cs
services.AddMicrosoftIdentityWebApiAuthentication(Configuration, "AzureAd");
app.UseAuthentication();

// WeatherForecastController
[Authorize]
[RequiredScope("Default")]

// appsettings.json
"AzureAd": {
    "Instance": "https://login.chinacloudapi.cn/",
    "ClientId": "my client id",
    "Domain": "my organization domain",
    "TenantId": "my organization tenant id",
    "Authority": "https://login.chinacloudapi.cn/my organization tenant id/"
}

Expected behavior I checked my token on jwt.ms, it shows everything is good.

Actual behavior I use Postman to request the API, and the API tells me issuer is null in my token.

[Gtyrande]

@bgavrilMS

1. I tried to set authority as sts.chinacloud.cn but response shows The issuer '(null)' is invalid also. So I prefer to think of it as a problem in msal.net.
2. Actually I’m not a Microsoft employee. Ha ha.

[shuichen17]

I use Microsoft.Identity.Web 1.25.3 and set "accessTokenAcceptedVersion": 2 Here is my code

services.AddAuthentication(options =>
                {
                    options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
                    options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
                })
                .AddJwtBearer("AzureAd", jwtOptions =>
                {
                    jwtOptions.TokenValidationParameters = new TokenValidationParameters
                    {
                        ValidateIssuer = false
                    };
                }).AddMicrosoftIdentityWebApi(Configuration.GetSection("AzureAd"));

              //  Set up basic authorization
                services.AddAuthorization(options =>
                {
                    options.AddPolicy("Bearer", new AuthorizationPolicyBuilder()
                    .AddAuthenticationSchemes(JwtBearerDefaults.AuthenticationScheme‌​)
                    .RequireAuthenticatedUser().Build());
                });

It works properly. My app is multitenant.