private static string ExtractPolicyText(string jwt) { string parsedPolicy = string.Empty; if (!string.IsNullOrEmpty(jwt)) { try { parsedPolicy = JoseHelper.ExtractJosePartField(jwt, 1, "AttestationPolicy").ToString(); // Policy is optionally double base64 URL encoded. We will attempt // to base64 URL decode a second time -- if this throws an exception, // that's OK -- we should just use value as it stands now. var doubleDecodedPolicy = Base64Url.DecodeString(parsedPolicy); parsedPolicy = doubleDecodedPolicy; } catch (Exception) { // Ignore on purpose } } return(parsedPolicy); }