Validating azure ad access token-CodePudding

I am trying to validate an azure ad access token like here: https://www.c-sharpcorner.com/article/how-to-validate-azure-ad-token-using-console-application/

I keep getting the error 'Object reference not set to an instance of an object' inside the tokenHandler.ValidateToken(...)

My code:

            string myTenant = "TENANT ID";
            var myAudience = "CLIENT ID";
            var myIssuer = String.Format(CultureInfo.InvariantCulture, "https://login.microsoftonline.com/{0}/v2.0", myTenant);
            var mySecret = "SECRET";
            var mySecurityKey = new SymmetricSecurityKey(Encoding.ASCII.GetBytes(mySecret));
            var stsDiscoveryEndpoint = String.Format(CultureInfo.InvariantCulture, "https://login.microsoftonline.com/common/v2.0/.well-known/openid-configuration", myTenant);
            var configManager = new ConfigurationManager<OpenIdConnectConfiguration>(stsDiscoveryEndpoint, new OpenIdConnectConfigurationRetriever());
            var config = await configManager.GetConfigurationAsync();

            var tokenHandler = new JwtSecurityTokenHandler();

            var validationParameters = new TokenValidationParameters
            {
                ValidAudience = myAudience,
                ValidIssuer = myIssuer,
                IssuerSigningKeys = config.SigningKeys,
                ValidateLifetime = false,
                IssuerSigningKey = mySecurityKey
            };

            var validatedToken = (SecurityToken)new JwtSecurityToken();

            // Throws an Exception as the token is invalid (expired, invalid-formatted, etc.)  
            tokenHandler.ValidateToken(token, validationParameters, out validatedToken);

instead of TENANT ID I have the tenant ID from azure. Instead of CLIENT ID I have the client ID from azure and instead of SECRET I have the value of the client secret made in azure.

CodePudding user response：

I really didn’t changed the code but it works now. :)