System.Configuration.BaseConfigurationRecord.DecryptConfigSection C# (CSharp) Метод

        private ConfigXmlReader DecryptConfigSection(ConfigXmlReader reader, ProtectedConfigurationProvider protectionProvider) {
            ConfigXmlReader     clone           = reader.Clone();
            IConfigErrorInfo    err             = (IConfigErrorInfo)clone;
            string              encryptedXml    = null;
            string              clearTextXml    = null;
            XmlNodeType         nodeType;

            clone.Read();

            // Save the file and line at the top of the section
            
            string filename = err.Filename;
            int lineNumber = err.LineNumber;
            int sectionLineNumber = lineNumber;

            if (clone.IsEmptyElement) {
                throw new ConfigurationErrorsException(SR.GetString(SR.EncryptedNode_not_found), filename, lineNumber);
            }

            //////////////////////////////////////////////////////////
            // Find the <EncryptedData> node
            for (;;) {
                clone.Read(); // Keep reading till we find a relavant node
                
                nodeType = clone.NodeType;
                
                if (nodeType  == XmlNodeType.Element && clone.Name == "EncryptedData")  { // Found it!
                    break;
                }

                if (nodeType == XmlNodeType.EndElement) {
                    throw new ConfigurationErrorsException(SR.GetString(SR.EncryptedNode_not_found), filename, lineNumber);
                }
                else if (nodeType  != XmlNodeType.Comment && nodeType != XmlNodeType.Whitespace) {
                    // some other unexpected content
                    throw new ConfigurationErrorsException(SR.GetString(SR.EncryptedNode_is_in_invalid_format), filename, lineNumber);
                }
            }

            //////////////////////////////////////////////////////////
            // Do the decryption

            // Save the line at the top of the <EncryptedData> node
            lineNumber = err.LineNumber;

            encryptedXml = clone.ReadOuterXml();
            try {
                clearTextXml = CallHostDecryptSection(encryptedXml, protectionProvider, ProtectedConfig);
            } catch (Exception e) {
                throw new ConfigurationErrorsException(SR.GetString(SR.Decryption_failed, protectionProvider.Name, e.Message), e, filename, lineNumber);
            }
            catch {
                throw new ConfigurationErrorsException(SR.GetString(SR.Decryption_failed, protectionProvider.Name, ExceptionUtil.NoExceptionInformation), filename, lineNumber);
            }

            // Detect if there is any XML left over after <EncryptedData>
            do {
                nodeType = clone.NodeType;
                
                if (nodeType == XmlNodeType.EndElement) {
                    break;
                }
                else if (nodeType  != XmlNodeType.Comment && nodeType != XmlNodeType.Whitespace) {
                    // Got other unexpected content
                    throw new ConfigurationErrorsException(SR.GetString(SR.EncryptedNode_is_in_invalid_format), filename, lineNumber);
                }
            } while (clone.Read());
            
            // Create a new reader, using the position of the original reader
            return new ConfigXmlReader(clearTextXml, filename, sectionLineNumber, true);
        }