Improving Web Application Security: Threats and - CGISecurity

812 Improving Web Application Security: Threats and Countermeasures(continued)if (target == null){if ((canEncrypt == false && canDecrypt == false) && (canUseMachineStore ==false && canUseUserStore == false))return true;elsereturn false;}if (!(target.GetType().Equals(this.GetType())))throw new ArgumentException("Argument must be of type EncryptionPermission.");// Cast the target to an EncryptionPermission.EncryptionPermission targetPerm = (EncryptionPermission)target;canTargetEncrypt = (targetPerm._permFlag &EncryptionPermissionFlag.Encrypt).Equals(EncryptionPermissionFlag.Encrypt);canTargetDecrypt = (targetPerm._permFlag &EncryptionPermissionFlag.Decrypt).Equals(EncryptionPermissionFlag.Decrypt);canTargetUseMachineStore = (targetPerm._storePermFlag &StorePermissionFlag.Machine).Equals(StorePermissionFlag.Machine);canTargetUseUserStore = (targetPerm._storePermFlag &StorePermissionFlag.User).Equals(StorePermissionFlag.User);// Every value set (true) in this permission must be in the target.// The following code checks to see if the current permission is a subset// of the target. If the current permission has something that the target// does not have, it cannot be a subset.if(canEncrypt == true && canTargetEncrypt == false)return false;if(canDecrypt == true && canTargetDecrypt == false)return false;if(canUseMachineStore == true && canTargetUseMachineStore == false)return false;if(canUseUserStore == true && canTargetUseUserStore == false)return false;}return true;14. Implement ISecurityEncodable.ToXml and FromXml. These methods convertinstances of a permission object into an XML format and vice-versa. Thesemethods are used to support serialization. This is used, for example, when thesecurity attribute is stored in assembly metadata.