Restore SEBPatch

SafeExamBrowser.Configuration/DataFormats/XmlSerializer.cs

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+/*
+ * Copyright (c) 2024 ETH Zürich, IT Services
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Xml;
+using SafeExamBrowser.Configuration.Contracts;
+using SafeExamBrowser.Configuration.Contracts.Cryptography;
+using SafeExamBrowser.Configuration.Contracts.DataFormats;
+using SafeExamBrowser.Logging.Contracts;
+
+namespace SafeExamBrowser.Configuration.DataFormats
+{
+	public class XmlSerializer : IDataSerializer
+	{
+		private readonly ILogger logger;
+
+		public XmlSerializer(ILogger logger)
+		{
+			this.logger = logger;
+		}
+
+		public bool CanSerialize(FormatType format)
+		{
+			return format == FormatType.Xml;
+		}
+
+		public SerializeResult TrySerialize(IDictionary<string, object> data, EncryptionParameters encryption = null)
+		{
+			var result = new SerializeResult();
+			var settings = new XmlWriterSettings { Encoding = new UTF8Encoding(), Indent = true };
+			var stream = new MemoryStream();
+
+			logger.Debug("Starting to serialize data...");
+
+			using (var writer = XmlWriter.Create(stream, settings))
+			{
+				writer.WriteStartDocument();
+				writer.WriteDocType("plist", "-//Apple Computer//DTD PLIST 1.0//EN", "https://www.apple.com/DTDs/PropertyList-1.0.dtd", null);
+				writer.WriteStartElement(XmlElement.Root);
+				writer.WriteAttributeString("version", "1.0");
+
+				result.Status = WriteDictionary(writer, data);
+				result.Data = stream;
+
+				writer.WriteEndElement();
+				writer.WriteEndDocument();
+				writer.Flush();
+				writer.Close();
+			}
+
+			logger.Debug($"Finished serialization -> Result: {result.Status}.");
+
+			return result;
+		}
+
+		private SaveStatus WriteArray(XmlWriter writer, List<object> array)
+		{
+			var status = SaveStatus.Success;
+
+			writer.WriteStartElement(XmlElement.Array);
+
+			foreach (var item in array)
+			{
+				status = WriteElement(writer, item);
+
+				if (status != SaveStatus.Success)
+				{
+					break;
+				}
+			}
+
+			writer.WriteEndElement();
+
+			return status;
+		}
+
+		private SaveStatus WriteDictionary(XmlWriter writer, IDictionary<string, object> data)
+		{
+			var status = SaveStatus.Success;
+
+			writer.WriteStartElement(XmlElement.Dictionary);
+
+			foreach (var item in data.OrderBy(i => i.Key))
+			{
+				status = WriteKeyValuePair(writer, item);
+
+				if (status != SaveStatus.Success)
+				{
+					break;
+				}
+			}
+
+			writer.WriteEndElement();
+
+			return status;
+		}
+
+		private SaveStatus WriteKeyValuePair(XmlWriter writer, KeyValuePair<string, object> item)
+		{
+			var status = SaveStatus.InvalidData;
+
+			if (item.Key != null)
+			{
+				writer.WriteElementString(XmlElement.Key, item.Key);
+				status = WriteElement(writer, item.Value);
+			}
+			else
+			{
+				logger.Error($"Key of item '{item}' is null!");
+			}
+
+			return status;
+		}
+
+		private SaveStatus WriteElement(XmlWriter writer, object element)
+		{
+			var status = default(SaveStatus);
+
+			if (element is List<object> array)
+			{
+				status = WriteArray(writer, array);
+			}
+			else if (element is Dictionary<string, object> dictionary)
+			{
+				status = WriteDictionary(writer, dictionary);
+			}
+			else
+			{
+				status = WriteSimpleType(writer, element);
+			}
+
+			return status;
+		}
+
+		private SaveStatus WriteSimpleType(XmlWriter writer, object element)
+		{
+			var name = default(string);
+			var value = default(string);
+			var status = SaveStatus.Success;
+
+			switch (element)
+			{
+				case byte[] data:
+					name = XmlElement.Data;
+					value = Convert.ToBase64String(data);
+					break;
+				case DateTime date:
+					name = XmlElement.Date;
+					value = XmlConvert.ToString(date, XmlDateTimeSerializationMode.Utc);
+					break;
+				case bool boolean when boolean == false:
+					name = XmlElement.False;
+					break;
+				case bool boolean when boolean == true:
+					name = XmlElement.True;
+					break;
+				case int integer:
+					name = XmlElement.Integer;
+					value = integer.ToString(NumberFormatInfo.InvariantInfo);
+					break;
+				case double real:
+					name = XmlElement.Real;
+					value = real.ToString(NumberFormatInfo.InvariantInfo);
+					break;
+				case string text:
+					name = XmlElement.String;
+					value = text;
+					break;
+				case null:
+					name = XmlElement.String;
+					break;
+				default:
+					status = SaveStatus.InvalidData;
+					break;
+			}
+
+			if (status == SaveStatus.Success)
+			{
+				writer.WriteElementString(name, value);
+			}
+			else
+			{
+				logger.Error($"Element '{element}' is not supported!");
+			}
+
+			return status;
+		}
+	}
+}