AzureFunctions.Authentication.LocalhostAuthProvider.AuthenticateIdToken C# (CSharp) Method

        private ClaimsPrincipal AuthenticateIdToken(HttpContextBase context, string id_token)
        {
            var config = OpenIdConfiguration.Current;
            var handler = new JwtSecurityTokenHandler();
            handler.CertificateValidator = X509CertificateValidator.None;
            if (!handler.CanReadToken(id_token))
            {
                throw new InvalidOperationException("No SecurityTokenHandler can authenticate this id_token!");
            }

            var parameters = new TokenValidationParameters();
            parameters.AllowedAudience = SecuritySettings.AADClientId;
            // this is just for Saml
            // paramaters.AudienceUriMode = AudienceUriMode.Always;
            parameters.ValidateIssuer = false;

            var tokens = new List<SecurityToken>();
            foreach (var key in config.IssuerKeys.Keys)
            {
                tokens.AddRange(key.GetSecurityTokens());
            }
            parameters.SigningTokens = tokens;

            // validate
            var principal = (ClaimsPrincipal)handler.ValidateToken(id_token, parameters);

            // verify nonce
            VerifyNonce(principal.FindFirst(NonceClaimType).Value);

            return principal;
        }